Postoperative Delirium

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Postoperative Delirium

• Presented By
• Tareq Salwati SSC-Anaes

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• Case Summary 1
• 27 years old lady, comes for debridement and skin
  grafting.
• She receives a balanced TIVA anesthetic, using
  propofol infusion and fentanyl.
• After extubation she became agitated, and
  combative.

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• Case Summary 2
• A 23-year-old previously healthy man undergoes
  general anesthesia for distal upper extremity
  surgery.
• The surgery and anesthetic progress uneventfully.
  After emergence and extubation and on transport
  to the postanesthesia care unit (PACU), the
  patient becomes disoriented and combative.

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Problem Analysis

• Definition
• Postoperative delirium is a state in which a
  patient has alterations in mental status that
  range from disorientation and lethargy to
  violent, harmful behavior and confusion.
• These patients are awake, but cannot or do not
  follow commands appropriately.

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Recognition

• Multifactorial Occurrence
• -Postoperative delirium is a multifactorial
  occurrence that needs to be promptly evaluated by
  an anesthesiologist whether on table, or in the
  PACU.
• -It also may only be a sign of a more
  life-threatening problem, such as airway
  obstruction, hypoxia or hypercarbia, which must
  be diagnosed immediately.

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Possible Sequelae

• -A significant sequela of postoperative delirium
  is that the patient is at extreme risk of
  physically harming himself or PACU personnel.
• -If the patient becomes combative, he or she may
  cause accidental trauma to self or the staff, and
  surgical repairs or indwelling lines and
  catheters may be in jeopardy.
• -Furthermore, the agitation may also produce a
  large sympathetic nervous system response leading
  to hypertension and tachycardia.

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Patient Assessment

• After restraining the patient, assess the
  patients preexisting medical condition,
  perioperative medications administered, course of
  anesthesia, and type of surgery performed.
• Next, a thorough physical examination and
  laboratory evaluation addressing arterial blood
  gas, serum glucose concentration, and
  electrolytes should follow.
• If a diagnosis is not forthcoming, a
  neurologic consultation and computed tomographic
  (CT) head scan should be considered.

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Risk Assessment

• -Postoperative delirium is not a rare occurrence
  in the immediate postoperative period.
• -It has been established that children and young
  adults are more likely to be agitated after
  emergence.
• -Young children can often be calmed by the
  presence of a parent in the PACU.
• -Furthermore, elderly patients are at
  substantially higher risk of having prolonged
  recovery of cognitive function after emergence,
  and thus may respond inappropriately in the PACU.

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• -Any patient with preoperative personality
  disturbances will generally have the same after
  emergence.
• -Patients with language, cultural or ethnic
  differences may have difficulty responding
  appropriately to PACU staff.
• -Finally, patients who have undergone surgical
  procedures with possibly grave consequences
  (e.g., tumor biopsies) may emerge with heightened
  agitation.

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Implications

• The consequences of postoperative delirium are
  twofold
• -First, identifying the cause and treating that
  appropriately, and
• -second, calming and carefully positioning and
  restraining the patient to avoid injury to
  himself or others.
• The former requires efficient, precise diagnosis
  and treatment to offset possible sequelae.

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• Management

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Emergence Phenomena

• The most likely reason for development of
  postoperative delirium is a transient period
  after emerging from general anesthesia during
  which the patient is unable to respond to sensory
  input appropriately.
• -A wide range of variation occurs among the
  responses, from somnolence and quiescence to
  hysteria and uncontrolled thrashing.
• -A patient with the latter will need calming,
  positioning, and restraint, all of which may
  escalate the state of restlessness.
• -As noted above, airway obstruction, hypoxia, or
  hypercarbia must be immediately assessed and
  treated if present.

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Anticholinergic Crises

• -Anticholinergics have historically been a major
  contributor to emergence delirium when given
  parenterally.
• -Both atropine and scopolamine, when administered
  perioperatively, may lead to postoperative
  disorientation.
• -They may concomitantly produce tachycardia,
  facial flushing, and dry mouth.
• -Moreover, anticholinergic medications
  administred ocularly for pupillary dilataion have
  also been implicated in causing emergence
  delirium.
• -Treatment consists of administering
  physostigmine 1.25 mg IV.

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Perioperative Meperidine

• -Perioperative meperidine (pethidine) in large
  doses, because of its atropine-like structure,
  can also cause these symptoms (i.e., similar to
  anticholinergic crises).
• -Furthermore, long term meperidine use may lead
  to build-up of normeperidine, its major
  metabolite, which has substantial convulsive
  properties.

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Other Perioperative Medications

• -Other perioperative medications that may
  produce disorientation on emergence include
  long-acting benzodiazepines (e.g., diazepam,
  lorazepam)
• -and the induction agents ketamine, etomidate,
  and propofol.
• Ketamine is probably the most widely
  recognized agent that causes postoperative
  dysphoria and hallucinations.
• Propofol has been implicated in induction of
  seizure activity in rare incidences

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• -Insufficient or lack of reversal of
  neuromuscular blockade may produce severe
  agitation and uncoordinated, disoriented
  movement.
• A patient will lack strength and purposeful
  movement and may need sedation and mechanical
  ventilation until the neuromuscular blockers are
  metabolized, if more reversal agent is not
  indicated.

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Alcohol and Recreational Drugs.

• -Acute perioperative intoxication with alcohol or
  recreational drugs and/or withdrawal from such
  agents must be considered.

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Pain and Discomfort

• -Patients who awaken after general anesthesia
  with substantial pain may be highly agitated
  prior to the administration of analgesics.
• -Distension of the stomach or the urinary
  bladder, poor body positioning, inappropriately
  tight dressings or traction, and any indwelling
  catheters or lines can also cause discomfort and
  agitation.

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Metabolic Alterations

• -Hypothermia increases the solubility of
  inhalational anesthetics, decreases metabolism of
  numerous sedative medications, and, if severe
  enough (lt30 degrees centigrade), may produce cold
  narcosis.
• -Serum glucose concentrations must be evaluated,
  as hypoglycemia is readily treatable with 50
  glucose administration IV.
• -Hyperglycemia, especially diabetic ketoacidosis
  and hyperosmolar, nonketotic coma may alter the
  mental status of the patient.
• The latter disorder is diagnosed by high blood
  glucose concentrations (gt600 mg/dL),
  hyperosmolarity, and lack of ketoacidosis.

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Metabolic Alterations

• Furthermore, hyperglycemia often occurs in
  patients without diabetes mellitus but with some
  type of severe illness ( sepsis, pneumonia, large
  burn).
• It may also occur with substantial dehydration,
  IV dextrose administration, or large dose steroid
  administration.
• -The coma that results from this disorder is most
  likely due to cerebral intracellular dehydration.
• Treatment is in the intensive care unit setting
  with insulin administration, hydration, potassium
  supplementation, and close monitoring of glucose
  concentration and electrolytes.

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Neurologic Injuries and Conditions

• -Careful neurologic examination and consultation
  may be of great value.
• Cerebral hypoxia leading to ischemia may occur
  secondary to prolonged hypoxemia or hypotension.
• -Trauma patients may develop unrecognized
  increased intracranial pressure or hemorrhage.
• -Intracranial hemorrhage may also occur due to
  large, abrupt hypertension in the perioperative
  period.
• -Cerebral thromboembolism may occur in many
  patients, especially those with known carotid
  vascular disease or those having undergone
  cardiac, vascular or radical neck surgery.

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Neurologic Injuries and Conditions

• Although rare, placement of intra-arterial,
  internal jugular or subclavian lines could cause
  thromboembolism.
• -Air embolism in cardiac surgery, air injection
  of intra-arterial lines, or intraveinous air
  administration in a patient with right-to-left
  shunt (paradoxical air embolism).
• -Fat embolism producing cerebral ischemia is very
  rare, but it should be considered in patients
  with long bone fractures.
• -Computed tomographic scans may be an invaluable
  aid in all of these situations.
• -Finally, unrecognized grand mal seizures due to
  an underlying seizure disorder or delirium
  tremens secondary to alcohol withdrawal must be
  considered.

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Treatment of Postoperative Delirium

• -Treatment of postoperative delirium , because in
  most cases it is transient, is usually
  supportive.
• -Patient reassurance, a quiet, calm environment,
  and close observation during the short interval
  required for dissipation of general anesthetic
  effects are often all that is necessary.
• -Nevertheless, more substantial intervention,
  such as the administration of analgesics for
  pain, or small doses of short-acting sedatives to
  relieve anxiety, may be required.

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• -Likewise, a patient may need to be restrained if
  agitation could cause harm to self or others in
  the PACU.
• -It must be reiterated that close observation and
  evaluation of all other possible medical reasons
  for the altered mental status must be performed
  prior to the administration of medications that
  may further alter a patients sensorium.

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Prevention

• -Because it is difficult to predict in which
  patient postoperative delirium will develop,
  preventing it, necessitates careful perioperative
  care of the patient, from preoperative assessment
  through discharge from the PACU.
• -A caring, dedicated PACU staff, who attempt to
  calm and reassure the patient while the medical
  evaluation progresses, is invaluable.

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• THANK YOU!

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Source

• Chapter 47-48
• Complications in anesthesia
• John L. Atlee, M.D.
• 1999