general surgery for dental students by dr. ahmad k. shahwan

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GENERAL SURGERY FOR DENTAL STUDENTS

• BY
• Dr. AHMAD K. SHAHWAN
• PH.D. GENERAL SURGERY

2
Approach to the Surgical Patient

• The management of surgical disorders requires not
  only the application of technical skills and
  training in the basic sciences to the problems of
  diagnosis and treatment but also a sympathy and
  indeed love for the patient. The surgeon must be
  a doctor, an applied scientist, an engineer, an
  artist. Because life or death often depends upon
  the validity of surgical decisions, the surgeon's
  judgment must be matched by courage in action and
  by a high degree of technical proficiency

3
Approach to the Surgical Patient

• History-
• physical Examination -
• Investigations-
• Pre-operative preparation -
• operation -
• post-operative treatment-
• management of complications.

4
Approach to the Surgical Patient

• The History
• At their first contact, the surgeon must gain the
  patient's confidence and convey the assurance
  that help is available and will be provided. The
  surgeon must demonstrate concern for the patient
  as a person who needs help and not just as a
  "case" to be processed. This is not always easy
  to do, and there are no rules of conduct except
  to be gentle and considerate.

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The History

• I- The chief complaint i.e. what the problem
  that bring the patient to the doctor its
  duration .
• II- The present history in full detail
• 1-when the complaint start exactly ? (day ,
  hour).
• 2-how it starts? (slowly ,abruptly )
• 3-its course ? (increasing , the same or
  decreasing ).
• 4- any associated symptoms? (pain vomiting ,fever
  ,drowsiness ,change in vision ,..) .
• 5- the provoking factors what increase the
  complaint?
• 6- the releasing factorswhat decrease the
  complaint ?
• 7- relieved by medication or not ?
• 8- constant or intermittent ,its duration for
  how long ?

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The History

• e.g. The pain
• The site
• The onset gradual ,sudden or explosive
• The character burning ,colicky, vague
  ,heaviness,..
• The severity mild ,moderate or sever .
• constant or intermittent .
• relieved by medication or not what medication ?
• Factors increase it movement ,eating, standing
  ,.
• Factors decrease it movement ,eating, standing
  ,
• Radiation to other site ?
• Associated symptoms vomiting ,fever ..

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The History

• E.g. vomiting
• What did the patient vomit? Food ,fluid ,
• How much?
• How often?
• What did the color of the vomitus ? yellow
  ,green, brown,.
• Was vomiting projectile?
• The taste of the vomitus ?acidic , bitter ,..

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The History

• III- The past history
• Any same complain before ? How it started how
  ended?
• Any other complain before? Related to the
  complaint or not related ?
• Any other diseases? hypertension. ,diabetes
  mellitus , cardiac problem,
• IV The drug history aspirin ,anticoagulant
  ,contraceptive pills ,chemotherapy .
• V- The surgical history any operation before,
  type of anesthesia ,any complication?

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The History

• VI- Nutritional history dehydration . Loss of
  electrolyte ,protein deficiency.
• VII- Menstrual history regularity ,duration ,
  amount,..
• VIII-Family history known disease in the family
  ,same disease in the family ,hereditary diseases?
  .
• IX- Environmental history.
• X- Habbit history smoking, alcohol ,drug abuse
  .
• XI- Hypersensitivity history .

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The physical examination

• All patients are sensitive and somewhat
  embarrassed at being examined .
• The examining room and table should be
  comfortable ,worm, closed, and drapes should be
  used if the patient is required to strip for the
  examination. A female nurse should be present if
  the patient is female. Most patients will relax
  if they are allowed to talk a bit during the
  examination, which is another reason for taking
  the past history while the examination is being
  done.

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The physical examination

• Inspection any scar, pulsation, swelling,
  redness, discharge, asymmetry, hair distribution,
  ulcers, wound ,.
• Palpation (superficial palpation for masses,
  tenderness,.deep palpation for deep masses )
• Percation to differentiate between air solid
  surfaces.
• Auscultation by use stethoscope to hear normal
  abnormal sounds.

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• E.g. if we find a lump (mass), we should know
• The site .
• The size .
• The shape .
• The edge (cut or rounded).
• Tenderness .
• Pulsation .
• Flactuality .
• Consistency .
• Mobility .
• The surface.
• Reducibility .
• Regional draining lymph node .

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• E.g. if we find an ulcer we should know
• The site .
• The size .
• The shape .
• The edge .
• The base (what you can feel) .
• The floor (what you can see) .
• The color .
• The secretion .
• The vascularity .
• Regional draining lymph node .

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Investigations

• I- Simple blood investigations
• C.B.C. (complete blood count) which reveals
  hemoglobin, white blood cells, red blood cells,
  platelets count,
• Blood group Rh-factor.
• Blood sugar (fasting or random or post brandial)
  .
• The kidney function tests (Blood urea ,serum
  creatinine) .
• Electrolyte Na ,K, Ca,..
• The liver function test (ALT, AST ,Serum
  bilirubin ,Serum protein albumin ) .
• P.T. P.T.T.

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Investigations

• II- urine exam (general culture).
• III- Stool exam (general culture).
• IV- ultrasonography.
• V- X-ray
• 1- simple X-ray (without dye) e.g. chest X-ray
  ,abdominal X-ray ,K.U.B. ,skull X-ray ,panorama
  X-ray, .
• 2- X-ray with dye e.g. barium meal ,barium
  enema, I.V.P
• 3- C.T. ( computerized tomography ) scan .
• 4- M.R.I. (magnetic resonance imaging) .
• VI- E.C.G . (electro cardio graphy )

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Investigations

• Special Examinations
• such as cystoscopy, gastroscopy, esophagoscopy,
  colonoscopy, angiography, and bronchoscopy are
  often required in the diagnosis of certain
  surgical disorders. The surgeon must be familiar
  with the indications and limitations of these
  procedures and be prepared to consult with
  colleagues in medicine and other surgical
  specialties as required.

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Pre-operative preparation

• According to the type of operation, we should do
• All the required investigations
• Prepare blood .
• Shaving the operation site.
• The patient take a bath.
• Examined by the anesthetist.
• Prepare I.C.U. if the patient need.
• Give him premedications like diazepam a night
  before the operation.
• Fasting 8 hours before the operation .
• The patient should enter the operation room in
  the optimum condition

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Approach to the Surgical Patient

• --operation -
• --post-operative treatment-
• --management of complications.
• (according to the type of the operation.)

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Postoperative Care

• The recovery from surgery can be divided into
  three phases
• (1) an immediate, or post-anesthetic phase
• (2) an intermediate phase, ( the hospitalization
  
  
  
  period)
• (3) a convalescent phase.
• During the first two phases, care is principally
  directed at maintenance of homeostasis, treatment
  of pain, and prevention and early detection of
  complications. The convalescent phase is a
  transition period from the time of hospital
  discharge to full recovery.
• The trend toward earlier postoperative discharge
  after major surgery make the 3rd phase more
  important.

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1-The Immediate Postoperative Period

• The major causes of early complications and death
  following major surgery are acute pulmonary,
  cardiovascular, and fluid derangements. The
  post-anesthesia care unit (PACU) is staffed by
  specially trained personnel and provided with
  equipment for early detection and treatment of
  these problems. All patients should be monitored
  in this specialized unit initially following
  major procedures .

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1-The Immediate Postoperative Period

• The patient can be discharged from the recovery
  room when cardiovascular, pulmonary, and
  neurologic function have returned to baseline,
  which usually occurs 13 hours following
  operation.
• Patients who require continuing ventilatory or
  circulatory support or who have other conditions
  that require frequent monitoring are transferred
  to an intensive care unit (I.C.U.) . In this
  setting, nursing personnel specially trained in
  the management of respiratory and cardiovascular
  emergencies are available.
• Monitoring equipment is available to enable
  early detection of cardio-respiratory
  derangements.

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Postoperative Orders in The Immediate
Postoperative Period

• The nursing team must be advised of the nature of
  the operation and the patient's condition.
• Postoperative orders should cover the following
  
• 1- Monitoring the following
• A- Vital Signs Blood pressure, pulse, and
  respiration should be recorded frequently until
  stable and then regularly until the patient is
  discharged from the recovery room. The frequency
  of vital sign measurements thereafter depends
  upon the nature of the operation and the course
  in the PACU. Continuous electrocardiographic
  monitoring is indicated for most patients in the
  PACU. Any major changes in vital signs should be
  communicated to the anesthesiologist and surgeon
  immediately.

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• B-Central Venous Pressure
• Central venous pressure should be recorded
  periodically in the early postoperative period if
  the operation has entailed large blood losses or
  fluid shifts, and invasive monitoring is
  available. A Swan-Ganz catheter for measurement
  of pulmonary artery wedge pressure is indicated
  under these conditions if the patient has
  borderline cardiac or respiratory function.

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• C- Fluid Balance
• The anesthetic record includes all fluid
  administered as well as blood loss and urine
  output during the operation. This record should
  be continued in the postoperative period and
  should also include fluid losses from drains and
  stomas. This aids in assessing hydration and
  helps to guide intravenous fluid replacement. A
  bladder catheter can be placed for frequent
  measurement of urine output. In the absence of a
  bladder catheter, the surgeon should be notified
  if the patient is unable to void within 68 hours
  after operation.

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• D- Other Types of Monitoring
• Depending on the nature of the operation and the
  patient's pre-existing conditions, other types of
  monitoring may be necessary. Examples include
  measurement of intracranial pressure and level of
  consciousness following cranial surgery and
  monitoring of distal pulses following vascular
  surgery or in patients with casts.

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• 2- Respiratory Care
• In the early postoperative period, the patient
  may remain mechanically ventilated or treated
  with supplemental oxygen by mask or nasal prongs.
  These orders should be specified. For intubated
  patients, tracheal suctioning or other forms of
  respiratory therapy must be specified as
  required. Patients who are not intubated should
  do deep breathing exercises frequently to prevent
  atelectasis.

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• 3- Position in Bed and Mobilization
• The postoperative orders should describe any
  required special positioning of the patient.
  Unless doing so is contraindicated, the patient
  should be turned from side to side every 30
  minutes until conscious and then hourly for the
  first 812 hours to minimize atelectasis.
• Early ambulation is encouraged to reduce venous
  stasis the upright position helps to increase
  diaphragmatic function.
• Venous stasis may also be minimized by
  intermittent compression of the calf by pneumatic
  stockings.

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• 4- Diet
• Patients at risk for emesis and pulmonary
  aspiration should have nothing by mouth until
  some gastrointestinal function has returned
  (usually within 4 days). Most patients can
  tolerate liquids by mouth shortly after return to
  full consciousness.
• 5- Administration of Fluid and Electrolytes
• Orders for postoperative intravenous fluids
  should be based on maintenance needs and the
  replacement of gastrointestinal losses from
  drains, fistulas, or stomas.

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• 6- Drainage Tubes
• Drain care should be included in the
  postoperative orders. Details such as type and
  pressure of suction, irrigation fluid and
  frequency, and skin exit site care should be
  specified. The surgeon should examine drains
  frequently, since the character or quantity of
  drain output may herald the development of
  postoperative complications such as bleeding or
  fistulas.
• 7- Medications
• Orders should be written for antibiotics,
  analgesics, gastric acid suppression, deep vein
  thrombosis prophylaxis, and sedatives. If
  appropriate, preoperative medications should be
  reinstituted. Careful attention should be paid to
  replacement of corticosteroids in patients at
  risk, since postoperative adrenal insufficiency
  may be life-threatening. Other medications such
  as antipyretics, laxatives, and stool softeners
  should be used selectively as indicated.

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• 8- Laboratory Examinations and Imaging
• The use of postoperative laboratory and
  radiographic examinations should be to detect
  specific abnormalities in high-risk groups. The
  routine use of daily chest radiographs, blood
  counts, electrolytes, and renal or liver function
  panels is not useful.

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The Intermediate Postoperative Period

• The intermediate phase starts with complete
  recovery from anesthesia and lasts for the rest
  of the hospital stay. During this time, the
  patient recovers most basic functions and becomes
  self-sufficient and able to continue
  convalescence at home.

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• 1- Care of the Wound
• Within hours after a wound is closed, the wound
  space fills with an inflammatory exudate.
  Epidermal cells at the edges of the wound begin
  to divide and migrate across the wound surface.
  By 48 hours after closure, deeper structures are
  completely sealed off from the external
  environment. Sterile dressings applied in the
  operating room provide protection during this
  period. Dressings over closed wounds should be
  removed on the third or fourth postoperative day.
  If the wound is dry, dressings need not be
  reapplied this simplifies periodic inspection.
  Dressings should be removed earlier if they are
  wet, because soaked dressings increase bacterial
  contamination of the wound.

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1- Care of the Wound

• Dressings should also be removed if the patient
  has manifestations of infection (such as fever or
  increasing wound pain). The wound should then be
  inspected and the adjacent area gently
  compressed. Any drainage from the wound should be
  examined by culture and Gram-stained smear.
  Removal of the dressing and handling of the wound
  during the first 24 hours should be done with
  aseptic technique. Medical personnel should wash
  their hands before and after caring for any
  surgical wound. Gloves should always be used when
  there is contact with open wounds or fresh
  wounds.

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1- Care of the Wound

• Generally, skin sutures or skin staples may be
  removed by the fifth postoperative day and
  replaced by tapes. Sutures should be left in
  longer (eg, for 2 weeks) in incisions that
• 1- cross creases (eg, groin, popliteal area)
• 2-for incisions closed under tension
• 3-for some incisions in the extremities (eg, the
  hand)
• 4-with incisions of any kind in debilitated
  patients.
• Sutures should be removed if suture tracts show
  signs of infection. If the incision is healing
  normally, the patient may be allowed to shower or
  bathe by the seventh postoperative day.

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1- Care of the Wound

• Fibroblasts proliferate in the wound space
  quickly, and by the end of the first
  postoperative week, new collagen is abundant in
  the wound. On palpation of the wound, connective
  tissue can be felt as a prominence (the healing
  ridge) and is evidence that healing is normal.
  Tensile strength is minimal for the first 5 days.
  It increases rapidly between the fifth and
  twentieth postoperative days and more slowly
  thereafter. Wounds continue to gain tensile
  strength slowly for about 2 years. In otherwise
  healthy patients, the wound should be subjected
  to only minor stress for 68 weeks. When wound
  healing is expected to be slower than normal
  (e.g., in elderly or debilitated patients or
  those taking corticosteroids), activity should be
  delayed even further

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1- Care of the Wound

• When a wound has been contaminated with bacteria
  during surgery, it is often best to leave the
  skin and subcutaneous tissues open and either to
  perform delayed primary closure or allow
  secondary closure to occur. The wound is loosely
  packed with fine-mesh gauze in the operating room
  and is left undisturbed for 45 days the packing
  is then removed. If at this time the wound
  contains only serous fluid or a small amount of
  exudate, the skin edges can be approximated with
  tapes. If drainage is considerable or infection
  is present, the wound should be allowed to close
  by secondary intention. In this case, the wound
  should be packed with moist-to-dry dressings,
  which are changed once or twice daily. The
  patient can usually learn how to care for the
  wound and should be discharged as soon as his or
  her general condition permits. Most patients do
  not require visiting nurses to assist with wound
  care at home.

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1- Care of the Wound

• Wound healing is faster if the state of nutrition
  is normal and there are no specific nutritional
  deficits. For example, vitamin C deficiency
  interferes with collagen synthesis and vitamin A
  deficiency decreases the rate of
  epithelialization. Deficiencies of copper,
  magnesium, and other trace metals decrease the
  rate of scar formation. Supplemental vitamins and
  minerals should be given postoperatively when
  deficiencies are suspected, but wound healing
  cannot be accelerated beyond the normal rate by
  nutritional supplements.
• Wound problems should be anticipated in patients
  taking corticosteroids, which inhibit the
  inflammatory response, fibroblast proliferation,
  and protein synthesis in the wound. Maturation of
  the scar and gain of tensile strength occur more
  slowly. Extra precautions include using
  non-absorbable suture materials for fascial
  closure, delaying removal of skin stitches, and
  avoiding stress in the wound for 36 months.

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2-Management of Drains

• Drains are used either to prevent or to treat an
  unwanted accumulation of fluid such as pus,
  blood, or serum. Drains are also used to evacuate
  air from the pleural cavity so that the lungs can
  reexpand. When used prophylactically, drains are
  usually placed in a sterile location. Strict
  precautions must be taken to prevent bacteria
  from entering the body through the drainage tract
  in these situations. The external portion of the
  drain must be handled with aseptic technique, and
  the drain must be removed as soon as it is no
  longer useful. When drains have been placed in an
  infected area, there is a smaller risk of
  retrograde infection of the peritoneal cavity,
  since the infected area is usually walled off.
  Drains should usually be brought out through a
  separate incision, because drains through the
  operative wound increase the risk of wound
  infection.

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2-Management of Drains

• Closed drains connected to suction devices are
  preferable to open drains (such as Penrose) that
  predispose to wound contamination. The quantity
  and quality of drainage should be recorded, and
  contamination minimized. When drains are no
  longer needed, they may be withdrawn entirely at
  one time if there has been little or no drainage
  or may be progressively withdrawn over a period
  of a few days.

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2-Management of Drains

• Sump drains (such as Davol drains) have an
  airflow system that keeps the lumen of the drain
  open when fluid is not passing through it, and
  they must be attached to a suction device. Sump
  drains are especially useful when the amount of
  drainage is large or when drainage is likely to
  plug other kinds of drains. Some sump drains have
  an extra lumen through which saline solution can
  be infused to aid in keeping the tube clear.
  After infection has been controlled and the
  discharge is no longer purulent, the large-bore
  catheter is progressively replaced with smaller
  catheters, and the cavity eventually closes.

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3-Postoperative Pulmonary Care

• The changes in pulmonary function observed
  following anesthesia and surgery are principally
  the result of decreased vital capacity,
  functional residual capacity (FRC), and pulmonary
  edema. These changes are accentuated in patients
  who are
• obese,
• who smoke heavily, or
• who have preexisting lung disease.
• Elderly patients are particularly vulnerable
  because they have decreased compliance, increased
  closing volume, increased residual volume, and
  increased dead space, all of which enhance the
  risk of postoperative atelectasis.

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3-Postoperative Pulmonary Care

• Pain is thought to be one of the main causes of
  shallow breathing postoperatively. Complete
  abolition of pain, however, does not completely
  restore pulmonary function . The principal means
  of minimizing atelectasis is deep inspiration.
  Early mobilization, encouragement to take deep
  breaths (especially when standing), and good
  coaching by the nursing staff suffice for most
  patients.

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4-Postoperative Fluid Electrolyte Management

• Postoperative fluid replacement should be based
  on the following considerations
• (1) maintenance requirements,
• (2) extra needs resulting from systemic factors
  (e.g., fever, burns),
• (3) losses from drains, and
• (4) requirements resulting from tissue edema and
  ileus (third space losses).
• Daily maintenance requirements for sensible and
  insensible loss in the adult are about 15002500
  mL depending on the patient's age, gender,
  weight, and body surface area. A rough estimate
  can be obtained by multiplying the patient's
  weight in kilograms times 30 (e.g., 1800 mL/24 h
  in a 60-kg patient). Maintenance requirements are
  increased by fever, hyperventilation, and
  conditions that increase the catabolic rate.

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4-Postoperative Fluid Electrolyte Management

• For patients requiring intravenous fluid
  replacement for a short period (most
  postoperative patients), it is not necessary to
  measure serum electrolytes at any time during the
  postoperative period, but measurement is
  indicated in more complicated patients (those
  with extra fluid losses, sepsis, preexisting
  electrolyte abnormalities, or other factors).
  Assessment of the status of fluid balance
  requires accurate records of fluid intake and
  output and is aided by weighing the patient
  daily.
• As a rule, 20002500 mL of 5 dextrose /or
  normal saline / or lactated Ringer's solution
  is given daily. Potassium should usually not be
  added during the first 24 hours after surgery,
  because increased amounts of potassium enter the
  circulation during this time as a result of
  operative trauma and increased aldosterone
  activity.

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4-Postoperative Fluid Electrolyte Management

• In most patients, fluid loss through a
  nasogastric tube is less than 500 mL/d and can be
  replaced by increasing the infusion used for
  maintenance by a similar amount. About 20 meq of
  potassium should be added to every liter of fluid
  used to replace these losses. However, with the
  exception of urine, body fluids are isosmolar and
  if large volumes of gastric or intestinal juice
  are replaced with normal saline solution,
  electrolyte imbalance will eventually result.
  Whenever external losses from any site amount to
  1500 mL/d or more, electrolyte concentrations in
  the fluid should be measured periodically, and
  the amount of replacement fluids should be
  adjusted to equal the amount lost.

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5-Postoperative Care of the Gastrointestinal
Tract

• In the immediate postoperative period, the
  stomach may be decompressed with a nasogastric
  tube. Nasogastric intubation was once used in
  almost all patients undergoing laparotomy to
  avoid gastric distention and vomiting, The
  nasogastric tube should be connected to low
  intermittent suction and irrigated frequently to
  ensure patency. The tube should be left in place
  for 23 days or until there is evidence that
  normal peristalsis has returned (e.g., return of
  appetite, audible peristalsis, or passage of
  flatus).

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5-Postoperative Care of the Gastrointestinal Tract

• Once the nasogastric tube has been withdrawn,
  fasting is usually continued for another 24
  hours, and the patient is then started on a
  liquid diet. Opioids may interfere with gastric
  motility and should be stopped in patients who
  have evidence of gastro-paresis beyond the first
  postoperative week. After most operations in
  areas other than the peritoneal cavity, the
  patient may be allowed to resume a regular diet
  as soon as the effects of anesthesia have
  completely worn off.

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6-Postoperative Pain

• Severe pain is a common sequela of intrathoracic,
  intra-abdominal, and major bone or joint
  procedures. About 60 of such patients perceive
  their pain to be severe, 25 moderate, and 15
  mild. In contrast, following superficial
  operations on the head and neck, limbs, or
  abdominal wall, less than 15 of patients
  characterize their pain as severe. The factors
  responsible for these differences include
  duration of surgery, degree of operative trauma,
  type of incision, and magnitude of intraoperative
  retraction. Gentle handling of tissues, expedient
  operations, and good muscle relaxation help
  lessen the severity of postoperative pain.

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6-Postoperative Pain

• While factors related to the nature of the
  operation influence postoperative pain, it is
  also true that the same operation produces
  different amounts of pain in different patients.
  This varies according to individual physical,
  emotional, and cultural characteristics. Much of
  the emotional aspect of pain can be traced to
  anxiety. Feelings such as helplessness, fear, and
  uncertainty contribute to anxiety and may
  heighten the patient's perception of pain.

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7-Physician-Patient Communication

• Close attention to the patient's needs, frequent
  reassurance, and genuine concern help minimize
  postoperative pain. Spending a few minutes with
  the patient every day in frank discussions of
  progress and any complications does more to
  relieve pain than many physicians realize.

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8-Parenteral Opioids

• Opioids are the mainstay of therapy for
  postoperative pain. Their analgesic effect is via
  two mechanisms
• (1) a direct effect on opioid receptors and
• (2) stimulation of a descending brain stem
  system that contributes to pain inhibition.
  Morphine ,pethidine tramal are the most widely
  used opioid for treatment of postoperative pain.
  Morphine may be administered intravenously,
  either intermittently or continuously

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Nonopioid Parenteral Analgesics

• They are non-steroidal anti-inflammatory drugs
  (NSAID) with potent analgesic and moderate
  anti-inflammatory activities. It is available in
  injectable form suitable for postoperative use .
• E.g. aspirin (acetyl salicylic acid ),diclofen
  sodium ,piroxicam,.

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Oral Analgesics

• Within several days following most surgical
  procedures, the severity of pain decreases to a
  point where oral analgesics suffice. Aspirin
  should be avoided as an analgesic
  postoperatively, since it interferes with
  platelet function, prolongs bleeding time, and
  interferes with the effects of anticoagulants.
  For most patients, a combination of acetaminophen
  with codeine (e.g., Tylenol) or with propoxyphene
  (analgan) suffices.
• As with all opioids, tolerance develops with
  long-term use.
• Continuous Epidural Analgesia
• Intercostal Block

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Postoperative Complications

• Postoperative complications may result from 1-
  the primary disease,
• 2- the operation, or
• 3-unrelated factors.
• Occasionally, one complication results from
  another previous one (eg, myocardial infarction
  following massive postoperative bleeding). The
  clinical signs of disease are often blurred in
  the postoperative period. Early detection of
  postoperative complications requires repeated
  evaluation of the patient by the operating
  surgeon and other team members .

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Postoperative Complications

• Prevention of complications starts in the
  preoperative period with evaluation of the
  patient's disease and risk factors. Improving the
  health of the patient before surgery is one goal
  of the preoperative evaluation. For example,
  cessation of smoking for 6 weeks before surgery
  decreases the incidence of postoperative
  pulmonary complications from 50 to 10.
  Correction of gross obesity decreases
  intra-abdominal pressure and the risk of wound
  and respiratory complications and improves
  ventilation postoperatively.
• The surgeon should explain the operation and the
  expected postoperative course to the patient and
  family. The preoperative hospital stay, if one is
  necessary, should be as short as possible both to
  reduce costs and to minimize exposure to
  antibiotic-resistant microorganisms. Adequate
  training in respiratory exercises planned for the
  postoperative period substantially decreases the
  incidence of postoperative pulmonary
  complications.

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Postoperative Complications

• Early mobilization, proper respiratory care, and
  careful attention to fluid and electrolyte needs
  are important. On the evening after surgery the
  patient should be encouraged to sit up, cough,
  breathe deeply, and walk, if possible. The
  upright position permits expansion of basilar
  lung segments, and walking increases the
  circulation of the lower extremities and lessens
  the danger of venous thromboembolism.
• In severely ill patients, continuous monitoring
  of systemic blood pressure and cardiac
  performance enables identification and correction
  of mild derangements before they become severe.

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I- Wound Complications

• 2- Seroma
• A seroma is a fluid collection in the wound other
  than pus or blood. Seromas often follow
  operations that involve elevation of skin flaps
  and transection of numerous lymphatic channels
  (eg, mastectomy, operations in the groin).
  Seromas delay healing and increase the risk of
  wound infection. Those located under skin flaps
  can usually be evacuated by needle aspiration.
  Compression dressings should then be applied to
  seal lymphatic leaks and prevent reaccumulation.
  Small seromas that recur may be treated by
  repeated evacuation. Seromas of the groin, which
  are common after vascular operations, are best
  left to resorb without aspiration, since the
  risks of introducing a needle (infection,
  disruption of vascular structures, etc) are
  greater than the risk associated with the seroma
  itself. If seromas persistor if they start
  leaking through the woundthe wound should be
  explored in the operating room and the lymphatics
  ligated.

59
I- Wound Complications

• 1- Hematoma
• Wound hematoma, a collection of blood and clot in
  the wound, is one of the most common wound
  complications and is almost always caused by
  imperfect hemostasis. Patients receiving aspirin
  or low-dose heparin have a slightly higher risk
  of developing this complication. The risk is much
  higher in patients who have been given
  systemically effective doses of anticoagulants
  and those with preexisting coagulopathies.
  Vigorous coughing or marked arterial hypertension
  immediately after surgery may contribute to the
  formation of a wound hematoma.
• Hematomas produce elevation and discoloration of
  the wound edges, discomfort, and swelling. Blood
  sometimes leaks through skin sutures. Neck
  hematomas following operations on the thyroid,
  parathyroid, or carotid artery are particularly
  dangerous, because they may expand rapidly and
  compromise the airway. Small hematomas may
  resorb, but they increase the incidence of wound
  infection. Treatment in most cases consists of
  evacuation of the clot under sterile conditions,
  ligation of bleeding vessels, and reclosure of
  the wound.

60
I- Wound Complications

• 3- Wound Dehiscence
• Wound dehiscence is partial or total disruption
  of any or all layers of the operative wound.
  Rupture of all layers of the abdominal wall and
  extrusion of abdominal viscera is evisceration.
  Wound dehiscence occurs in 13 of abdominal
  surgical procedures. Systemic and local factors
  contribute to the development of this
  complication.
• 3-1-- Systemic Risk Factors
• Dehiscence is rare in patients under age 30 but
  affects about 5 of patients over age 60 having
  laparotomy. It is more common in patients with
  diabetes mellitus, uremia, immunosuppression,
  jaundice, sepsis, hypoalbuminemia, and cancer in
  obese patients and in those receiving
  corticosteroids.

61

• 3-2- Local Risk Factors
• The three most important local factors
  predisposing to wound dehiscence are inadequate
  closure, increased intra-abdominal pressure, and
  deficient wound healing. Dehiscence often results
  from a combination of these factors rather than
  from a single one. The type of incision
  (transverse, midline, etc) does not influence the
  incidence of dehiscence.
• E.g. Adequacy of Closure
• This is the single most important factor. The
  fascial layers give strength to a closure, and
  when fascia disrupts, the wound separates.
  Accurate approximation of anatomic layers is
  essential for adequate wound closure. Most wounds
  that dehisce do so because the sutures tear
  through the fascia. Prevention of this problem
  includes performing a neat incision, avoiding
  devitalization of the fascial edges by careful
  handling of tissues during the operation, placing
  and tying sutures correctly, and selecting the
  proper suture material. Sutures must be placed
  23 cm from the wound edge and about 1 cm apart.
  Dehiscence is often the result of using too few
  stitches and placing them too close to the edge
  of the fascia. Ostomies and drains should be
  brought out through separate incisions to reduce
  the rate of wound infection and disruption.

62
II- Respiratory Complications

• Respiratory complications are the most common
  single cause of morbidity after major surgical
  procedures and the second most common cause of
  postoperative deaths in patients older than 60
  years.
• Patients undergoing chest and upper abdominal
  operations are particularly prone to pulmonary
  complications. The incidence is lower after
  pelvic surgery and even lower after extremity or
  head and neck procedures.
• Pulmonary complications are more common after
  emergency operations.
• Special hazards are posed by preexisting chronic
  obstructive pulmonary disease (chronic
  bronchitis, emphysema, asthma, pulmonary
  fibrosis). Elderly patients are at much higher
  risk because they have decreased compliance,
  increased residual volumes, and increased dead
  space, all of which predispose to atelectasis.

63
II- Respiratory Complications

• 1- Atelectasis
• Atelectasis, the most common pulmonary
  complication, affects 25 of patients who have
  abdominal surgery. It is more common in patients
  who are elderly or overweight and in those who
  smoke or have symptoms of respiratory disease. It
  appears most frequently in the first 48 hours
  after operation and is responsible for over 90
  of febrile episodes during that period. In most
  cases, the course is self-limited and recovery
  uneventful.

64

• Atelectasis is usually manifested by fever
  (pathogenesis unknown), tachypnea, and
  tachycardia. Physical examination may show
  elevation of the diaphragm and decreased breath
  sounds.
• Postoperative atelectasis can be largely
  prevented by early mobilization, frequent changes
  in position, encouragement to cough, and
  physiotherapy. Preoperative teaching of
  respiratory exercises and postoperative execution
  of these exercises prevents atelectasis in
  patients without preexisting lung disease.
• Treatment consists of clearing the airway by
  chest percussion, coughing, or nasotracheal
  suction. Bronchodilators and mucolytic agents
  given by nebulizer may help in patients with
  severe chronic obstructive pulmonary disease.
  Atelectasis from obstruction of a major airway
  may require intrabronchial suction through an
  endoscope, a procedure that can usually be
  performed at the bedside with mild sedation

65

• 2- Pulmonary Aspiration
• Aspiration of oropharyngeal and gastric contents
  is normally prevented by the gastroesophageal and
  pharyngoesophageal sphincters. Insertion of
  nasogastric and endotracheal tubes and depression
  of the central nervous system by drugs interfere
  with these defenses and predispose to aspiration.
  Other factors, such as gastroesophageal reflux,
  food in the stomach, or position of the patient,
  may play a role. Trauma victims are particularly
  likely to aspirate regurgitated gastric contents
  when consciousness is depressed. Patients with
  intestinal obstruction and pregnant womenwho
  have increased intra-abdominal pressure and
  decreased gastric motilityare also at high risk
  of aspiration. Two-thirds of cases of aspiration
  follow thoracic or abdominal surgery, and of
  these, one-half result in pneumonia. The death
  rate for grossly evident aspiration and
  subsequent pneumonia is about 50.

66

• The magnitude of pulmonary injury produced by
  aspiration of fluid, usually from gastric
  contents, is determined by the volume aspirated,
  its pH, and the frequency of the event. If the
  aspirate has a pH of 2.5 or less, it causes
  immediate chemical pneumonitis, which results in
  local edema and inflammation, changes that
  increase the risk of secondary infection.
• Aspiration of solid matter can produce airway
  obstruction. Obstruction of distal bronchi,
  though well tolerated initially, can lead to
  atelectasis and pulmonary abscess formation. The
  basal segments are affected most often.
  Tachypnea, fever, and hypoxia are usually present
  within hours less frequently, cyanosis,
  wheezing, and apnea may appear. In patients with
  massive aspiration, hypovolemia caused by
  excessive fluid and colloid loss into the injured
  lung may lead to hypotension and shock.

67

• Aspiration can be prevented by preoperative
  fasting, proper positioning of the patient, and
  careful intubation. A single dose of cimetidine
  before induction of anesthesia may be of value in
  situations where the risk of aspiration is high.
• Treatment of aspiration involves reestablishing
  patency of the airway and preventing further
  damage to the lung. Endotracheal suction should
  be performed immediately, as this procedure
  confirms the diagnosis and stimulates coughing,
  which helps to clear the airway. Bronchoscopy may
  be required to remove solid matter. Fluid
  resuscitation should be undertaken concomitantly.
  Antibiotics are used initially when the aspirate
  is heavily contaminated they are used later to
  treat pneumonia.

68
3- Postoperative Pneumonia

• Pneumonia is the most common pulmonary
  complication among patients who die after
  surgery. It is directly responsible for death in
  more than half of these patients. Patients whos
  requiring prolonged ventilatory support are at
  highest risk for developing postoperative
  pneumonia.
• Atelectasis, aspiration, and copious secretions
  are important predisposing factors.
• The clinical manifestations of postoperative
  pneumonia are fever, tachypnea, increased
  secretions, and physical changes suggestive of
  pulmonary consolidation. A chest x-ray usually
  shows localized parenchymal consolidation.

69
3- Postoperative Pneumonia

• Maintaining the airway clear of secretions is of
  paramount concern in the prevention of
  postoperative pneumonia. Respiratory exercises,
  deep breathing, and coughing help prevent
  atelectasis, which is a precursor of pneumonia.
• Treatment consists of measures to aid the
  clearing of secretions and administration of
  antibiotics. Sputum obtained directly from the
  trachea, usually by endotracheal suctioning, is
  required for specific identification of the
  infecting organism.

70
III-Fat Embolism

• Fat embolism is relatively common but only rarely
  causes symptoms. Fat particles can be found in
  the pulmonary vascular bed in 90 of patients who
  have had fractures of long bones or joint
  replacements. Fat embolism can also be caused by
  exogenous sources of fat, such as blood
  transfusions, intravenous fat emulsion, or bone
  marrow transplantation. Fat embolism symptoms
  consist of neurologic dysfunction, respiratory
  insufficiency, and petechiae of the axillae,
  chest, and proximal arms.
• Fat embolism characteristically begins 1272
  hours after injury but may be delayed for several
  days. The diagnosis is clinical. The finding of
  fat droplets in sputum and urine is common after
  trauma.

71
IV- Cardiac Complications

• Cardiac complications following surgery may be
  life-threatening. Their incidence is reduced by
  appropriate preoperative preparation.
• Dysrhythmias, unstable angina, heart failure, or
  severe hypertension should be corrected before
  surgery whenever possible. Valvular
  diseaseespecially aortic stenosislimits the
  ability of the heart to respond to increased
  demand during operation or in the immediate
  postoperative period. When aortic stenosis is
  recognized preoperatively , the incidence of
  major perioperative complications is small. Thus,
  patients with preexisting heart disease should be
  evaluated by a cardiologist preoperatively.

72
IV- Cardiac Complications

• General anesthesia depresses the myocardium, and
  some anesthetic agents predispose to
  dysrhythmias.
• Monitoring of cardiac activity and blood pressure
  during the operation detects dysrhythmias and
  hypotension early.
• In patients with a high cardiac risk, regional
  anesthesia may be safer than general anesthesia
  for procedures below the umbilicus.
• Non-cardiac complications may affect the
  development of cardiac complications by
  increasing cardiac demands in patients with a
  limited reserve. E.g. Postoperative sepsis and
  hypoxemia. Fluid overload can produce acute left
  ventricular failure.
• Patients with coronary artery disease,
  dysrhythmias, or low cardiac output should be
  monitored postoperatively in an intensive care
  unit.

73
V- Complications of Intravenous Therapy
Hemodynamic Monitoring

• 1- Air Embolism
• Air embolism may occur during or after insertion
  of a venous catheter or as a result of accidental
  introduction of air into the line. Intravenous
  air lodges in the right atrium, preventing
  adequate filling of the right heart. This is
  manifested by hypotension, jugular venous
  distention, and tachycardia.
• This complication can be avoided by placing the
  patient in the Trendelenburg position when a
  central venous line is inserted.
• Emergency treatment consists of aspiration of
  the air with a syringe. If this is unsuccessful,
  the patient should be positioned right side up
  and head down, which will help dislodge the air
  from the right atrium and return circulatory
  dynamics to normal.

74
V- Complications of Intravenous Therapy
Hemodynamic Monitoring

• 2- Phlebitis
• A needle or a catheter inserted into a vein and
  left in place will in time cause inflammation at
  the entry site. When this process involves the
  vein, it is called phlebitis. Factors determining
  the degree of inflammation are the nature of the
  cannula, the solution infused, bacterial
  infection, and venous thrombosis. Phlebitis is
  one of the most common causes of fever after the
  third postoperative day. The symptomatic triad of
  induration, edema, and tenderness is
  characteristic. Prevention of phlebitis is best
  accomplished by observance of aseptic techniques
  during insertion of venous catheters, frequent
  change of tubing (ie, every 4872 hours),

75
VI-Postoperative Fever

• Fever occurs in about 40 of patients after major
  surgery. In most patients the temperature
  elevation resolves without specific treatment.
  However, postoperative fever may herald a serious
  infection, and it is therefore important to
  evaluate the patient clinically.
• Normal body tempreture is 36.737.3c
• Fever within 48 hours after surgery is usually
  caused by
• 1- atelectasis Re-expansion of the lung causes
  body temperature to return to normal.
• 2- reactions to drugs ,anesthesia ,blood
  transfusion , absorption of haematoma ,

76
VI-Postoperative Fever

• fever appears in the third postoperative day,
  atelectasis is a less likely explanation. The
  differential diagnosis of fever at this time
  includes catheter-related phlebitis, pneumonia,
  and urinary tract infection. A directed history
  and physical examination complemented by focused
  laboratory and radiologic studies usually
  determine the cause.
• Patients without infection are rarely febrile
  after the fifth postoperative day.
• Fever in the fifth postoperative day suggests
  wound infection or, less often, anastomotic
  breakdown and intra-abdominal abscesses.

77
VI-Postoperative Fever

• Fever after the 7th postoperative day (in the
  2nd week ) suggests deep venous thrombosis in the
  calf muscles .

78
Special Medical Problems in Surgical Patients 

• Diabetes Mellitus
• Diabetic patients undergo more surgical
  procedures than do non-diabetics, and management
  of the diabetic patient before, during, and after
  surgery is an important responsibility of the
  surgeon. Fortunately, because close control of
  fluids, electrolytes, glucose, and insulin is now
  possible in the operating room, control of blood
  glucose levels during the peri-operative period
  is usually relatively simple. Marked
  hyperglycemia should be avoided during surgery
  the greater danger, however, is from severe
  unrecognized hypoglycemia.

79
Diabetes Mellitus

• Preoperative Workup
• Blood glucose concentrations may be elevated in
  diabetic patients during the preoperative period.
  Physical trauma, if present, combined with the
  emotional and physiologic stress of the illness
  may cause epinephrine and cortisol levels to
  rise, in each case resulting in increased blood
  glucose levels.

80
Diabetes Mellitus

• The preoperative workup of patients with diabetes
  mellitus includes
• A thorough physical examination, with special
  care to discover occult infections
• An ECG to rule out myocardial infarction
• A chest x-ray to identify hidden pneumonia or
  pulmonary edema.
• A complete urinalysis can rule out urinary tract
  infection and proteinuria, the earliest signs of
  diabetic renal disease.
• Serum potassium levels are measured to check for
  hypokalemia or hyperkalemia .
• Serum creatinine levels are used to assess renal
  function.
• The serum glucose concentration should ideally
  be between 100 and 200 mg/dL,

81
Preoperative Intraoperative Management of
Diabetic Patients

• Type 2 (Non-Insulin-Dependent) Diabetes Mellitus
• Approximately 85 of diabetics over age 50 years
  have only a moderately decreased ability to
  produce and secrete insulin, and when at home
  they can usually be controlled by diet or by oral
  hypoglycemic drugs. If the serum glucose level is
  below 200 mg/dL on the morning of surgery, oral
  hypoglycemic drugs should be withheld and 5
  glucose solution should be administered
  intravenously at a rate of about 100 mL/h. This
  means that over a 10-hour period, only 50 g of
  glucose would be given by contrast, during an
  average day, a diabetic on a normal diet would
  consume four to five times as much carbohydrate
  (ie, 200250 g).

82

• If the operation is lengthy, blood glucose levels
  should be measured every 34 hours during surgery
  to ensure adequate glucose control. The goal is
  to maintain glucose levels between 100 and 200
  mg/dL,
• Type 1 (Insulin-Dependent) Diabetes Mellitus
• Type 1 patients require insulin during surgery.
  It can be administered by any of the following
  methods
• (1) subcutaneous administration of short-acting
  insulin
• (2) constant infusion of a mixture of glucose
  and insulin or
• (3) separate infusions of glucose and insulin.
• blood glucose levels should be monitored at
  least every 2 hours during the procedure to avoid
  hypoglycemia below 60 mg/dL and hyperglycemia
  above 200 mg/dL.
• Blood glucose levels can be measured rapidly
  during surgery with a portable electronic glucose
  analyzer.

83
Postoperative Care

• Hypoglycemia, the most common postoperative
  complication, most often follows the use of
  long-acting insulin given subcutaneously before
  surgery. Although hypoglycemia may also occur if
  the intravenous insulin infusion is excessive in
  relation to that of the glucose, an infusion of
  1.5 units or less of insulin per hour, when given
  with 5 glucose, rarely results in hypoglycemia.
  Blood glucose levels should be measured every 24
  hours and the patient monitored for signs and
  symptoms of hypoglycemia (eg, anxiety,
  tremulousness, profuse sweating without fever).
  When hypoglycemia is detected, the amount of
  glucose infused should be promptly increased and
  the insulin decreased.

84
Postoperative Care

• In the intermediate phase we do blood sugar
  every 6 hours give soluble insulin
  subcutaneously according to the following table

85

• This is continue till the patient can drink /0r
  eat then the patient return to his old medical
  treatment do blood sugar twice daily to be sure
  that its level below 180 mg/dl.
• A marked increase in glucose and insulin
  requirements postoperatively suggests the
  presence of occult infection (eg, wound
  infection, cellulitis at the intravenous site,
  urinary tract infection, or unrecognized
  aspiration pneumonia).
• Adjustments in the rate of glucose or insulin
  administration must be based on blood glucose
  levels.

86
Hypertension

• Patients with uncomplicated and controlled
  hypertension usually tolerate surgery well. The
  patient advised to took his medication till the
  day of surgery at the morning of surgery
  continue after the surgery if possible or replace
  it with parentral drugs.
• The patient should stop aspirin a week before
  surgery an internist should consulted before
  the operation.

87
Respiratory Disease

• Acute Upper Respiratory Tract Infections
• Both anesthesia and surgery provide opportunities
  for the spread of infection because respiratory
  defense mechanisms are compromised and
  instrumentation of the airway may be required.
  Therefore, the presence of a cold, pharyngitis,
  or tonsillitis is a relative contraindication to
  elective surgery, since viral infections decrease
  defense mechanisms against bacterial infections.
• If surgery is necessary, the appropriate
  antibiotic should be administered and
  manipulation of the infected area avoided when
  possible.
• Acute Lower Respiratory Tract Infections
  (Tracheitis, Bronchitis, Pneumonia)
• These infections are absolute contraindications
  to elective surgery. For emergency surgery,
  therapy includes humidification of inhaled gases,
  removal of lung secretions, and continued
  administration of bronchodilators and antibiotics.

88

• Bronchial Asthma
• patients with bronchial asthma who are undergoing
  surgery are at increased risk of pulmonary
  complications. Preoperative management includes
  adjustment of bronchodilator medication,
  cessation of smoking, and treatment of infection.
  
• Intraoperative bronchoconstriction from
  mechanical stimulation of the airway must be
  prevented so that appropriate anesthetics can be
  given in adequate concentrations. Since
  intraoperative use of bronchodilators may be
  necessary, adverse interactions between
  anesthetic agents and bronchodilators must be
  avoided. Many patients with bronchial asthma have
  been treated with corticosteroids and require
  corticosteroid therapy in the perioperative period

89
aneamia

• Surgical patients with anemia should undergo a
  thorough workup to identify and treat the
  underlying cause before elective procedures are
  undertaken. A detailed history should be obtained
  to identify any symptoms of blood loss from the
  genitourinary and gastrointestinal tracts. A
  history of renal, hepatic, hematologic, or
  endocrinologic disorders and a medication history
  should be elicited. A history suggestive of
  hemolytic episodes or a family history of anemia
  may offer clues to the diagnosis. Signs of
  pallor, jaundice, lymphadenopathy, and
  organomegaly should be sought on physical
  examination.
• A complete laboratory evaluation including CBC,
  reticulocyte count, peripheral smear, and stool
  test for occult blood should be done.
• Correctable causes of anemia, like
  deficiencies of iron, folate, and vitamin B12 ,
  should be treated.
• Preoperative red blood cell (RBC) transfusions
  are not routinely recommended, and the decision
  to transfuse should be based on the need to
  improve tissue oxygenation.

90
pregnancy

• The Pregnancy may alter or mask the signs and
  symptoms of the particular presentation or course
  of disease, so that diagnosis is made more
  difficult. Furthermore, the fetus and changes in
  maternal physiology and anatomy must be
  considered in the use of diagnostic tests,
  medical therapy, and the planning of surgical
  procedures.
• Any major operation represents a risk not only
  to the mother but to the fetus as well. An
  increase in both preterm delivery and growth
  restriction in infants that resulted from
  pregnancies that involved a surgical procedure.
• Although there is no evidence that congenital
  anomalies are induced in the developing fetus by
  anesthesia, semielective procedures should be
  deferred until the second trimester of pregnancy,
  exercising the greatest precautions to prevent
  hypoxia and hypotension.
• Emergent surgical procedures should proceed as
  necessary however, changes in maternal
  physiologyparticularly in cardiac output and
  maternal blood volumeas well as of the size of
  the gravid uterus must be considered.

91
Normal values
92
Fluid Electrolyte Management

• Fluid intake (input ) is derived from two
  sources
• (1) exogenous and
• (2) endogenous.
• Exogenous water is either drunk or ingested in
  solid food. The quantities vary within wide
  limits, but average 23 litres per 24 hours, of
  which nearly half is contained in solid food.
• The water requirements of infants and children
  are relatively greater than those of adults
  because of
• (1) the larger surface area per unit of body
  weight
• (2) the greater metabolic activity due to
  growth (3) the comparatively poor
  concentrating ability of the immature kidney.
• Endogenous water is released during the
  oxidation of ingested food the amount is
  normally less than 500 ml / 24 hours. However,
  during starvation, this amount is supplemented by
  water released from the breakdown of body
  tissues.

93

• Fluid output
• Water is lost from the body by four routes.
• 1  By the lungs. About 400 ml of water is lost
  in expired air each 24 hours. In a dry
  atmosphere, and when the respiratory rate is
  increased, the loss is correspondingly greater .
• 2By the skin. When the body becomes overheated,
  there is visible perspiration, but throughout
  life invisible perspiration is always occurring.
  The cutaneous fluid loss varies with the
  atmospheric temperature and humidity, muscular
  activity and body temperature. In a temperate
  climate the average loss is between 600 and 1000
  ml / 24 hours.
• 3 Faeces. Between 60 and 150 ml of water are
  lost by this route daily. In diarrhoea this
  amount is greatly multiplied.
• 4 Urine. The output of urine is under the
  control of multiple influences, such as blood
  volume, hormonal and nervous influences, among
  which the antidiuretic hormone acts by
  stimulating the reabsorption of water from the
  renal tubules. The normal urinary output is
  approximately 1500 ml / 24 hours, and provided
  that the kidneys are healthy, the specific
  gravity of the urine bears a direct relationship
  to the volume. A minimum urinary output of
  approximately 400 ml / 24 hours is required to
  excrete the end products of protein metabolism.

94

• Water depletion
• Pure water depletion is usually due to diminished
  intake. This may be due to lack of availability,
  difficulty or inability to swallow because of
  painful conditions of the mouth and pharynx, or
  obstruction in the oesophagus. Pure water
  depletion may also follow the increased loss from
  the lungs after tracheostomy. This loss may be as
  much as 500 ml in excess of the normal insensible
  loss. After tracheostomy, humidification of the
  inspired air is an important preventive measure.
• Clinical features
• The main symptoms are weakness and intense
  thirst. The urinary output is diminished and its
  specific gravity increased.
• Treatment by drinking water /or give 5glucose
  water solution.

95

• Water intoxication
• This can occur when excessive amounts of water,
  low sodium or hypotonic solutions are taken or
  given by any route. The commonest cause on
  surgical wards is the over-prescribing of
  intravenous 5 glucose solutions to postoperative
  patients.
• Similarly, water intoxication can occur if the
  body retains water in excess to plasma solutes.
  This can be seen in the syndrome of inappropriate
  antidiuretic hormone (SIADH) secretion which is
  most commonly associated with lung conditions
  such as lobar pneum