Rural Obstetric Anaesthesia

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Rural Obstetric Anaesthesia

• Dr Simon Tomlinson
• Staff Anaesthetist, Geelong Hospital

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Background

• 585, 000 women die each year from obstetric
  related causes - 97 3rd world.
• In 1953 maternal mortality was 1 in 1500.
• In 1996 maternal mortality was 1 in 30,000.
• In the U.K. anaesthesia is ninth leading cause of
  maternal mortality.
• Over half of these (anaesthetic) deaths are due
  to airway misadventure.
• Caesarean section death rate (12000) gt vaginal
  delivery

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Anaesthetic issues

• Anaesthesia for Caesarean Section
• Inadequate regional anaesthesia (too high or too
  low!)
• Obstetric haemorrhage
• Pre-eclampsia
• Foetal resuscitation

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Remember the Basics

• Prepare theatre, blood bank, assistance.
• Communicate with obstetrician and paediatrician.
• History, Examine (airway), Reassure.
• Oxygen on mother - contentious
• Acid prophylaxis contentious
• Lateral tilt.
• Large IV (before you start!)
• Regional anaesthesia if not contraindicated.

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Anaesthesia for caesarean section

• Elective C/S who should be transferred
  elsewhere?
• Maternal indications
• Surgical indications
• Foetal indications

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Anaesthesia for caesarean section

• Elective C/S who should be transferred
  elsewhere?
• Maternal indications
• Surgical indications
• Foetal indications
• GA v regional. How do you decide?
• Contra-indications to regional
• Contra-indications to general

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Contra-indications to regional

• Absolute
• Maternal refusal
• Clotting disorders
• Hypovolaemia with active bleeding
• Relative
• Sepsis
• Fluctuating neurological conditions
• Anticipated major blood loss (placenta praevia)
• Severe foetal distress (controversial)

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Contra-indications to general

• Everybody?

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Contra-indications to general

• Everybody?
• Maternal choice
• Anticipated or known difficult intubation
• Significant (brittle) asthma
• PET unless coagulopathic
• Allergy to Suxamethonium
• Sick neonate (contentious)

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Management of regional C/S

• Spinal v Epidural v CSE
• Drugs and fluids
• Common problems
• Hypotension
• Tachycardia/bradycardia
• Nausea
• Shivering
• Discomfort
• Anxiety

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Management of C/S under regional

• Uncommon problems
• Failed block
• High spinal
• Chest pain

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Management of C/S under GA

• Is this really necessary?
• Am I prepared?
• Does everybody else know what the plan is?
• What do we worry about?
• Failed intubation
• Awareness
• Foetal well-being
• What comes first the chicken or the egg?

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Remember the Basics

• Prepare theatre, blood bank, assistance.
• Communicate with obstetrician and paediatrician.
• History, Examine (airway), Reassure.
• Acid prophylaxis contentious
• Lateral tilt.
• Large IV (before you start!)

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Management of the airway

• Assessment
• Positioning
• Patient
• Assistant do they know how to do cricoid
  pressure?
• Drugs and equipment
• Surgeon
• Airway, BreathingIntubation

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Positioning for intubation
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Management of the airway

• Assessment
• Positioning
• Patient
• Assistant do they know how to do cricoid
  pressure?
• Drugs and equipment
• Surgeon
• Airway, BreathingIntubation

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Airway management cont.

• Pre-oxygenation
• Induction
• Laryngoscopy

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Airway management cont.

• Pre-oxygenation
• Induction
• Laryngoscopy
• Oh meconium!!

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Difficult intubation(can ventilate)

• Can ventilate
• Optimisation of view
• Head position
• Manipulate/remove cricoid pressure
• BURP
• Alternate strategies for passing ETT (partial
  view)
• Introducer
• BOUGIE
• Smaller ETT
• What else?

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Difficult intubation(can ventilate)

• When do you stop during an intubation?

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Difficult intubation(can ventilate)

• When do you stop during an intubation?
• SaO2 lt 90
• Evidence of reflux
• Evidence of trauma
• When do you stop trying to intubate?

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Difficult intubation(can ventilate)

• When do you stop during an intubation?
• SaO2 lt 90
• Evidence of reflux
• Evidence of trauma
• When do you stop trying to intubate?
• Decreased ability to oxygenate between attempts
• Trauma to larynx
• After 3 attempts (max)
• Suxamethonium wearing off

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Difficult intubation(cant ventilate)

• First attempt at intubation is a dismal failure
• Cant intubate, cant ventilate
• This Is an Emergency Call for Help
• Optimise the airway
• How?

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Difficult intubation(cant ventilate)

• First attempt at intubation is a dismal failure
• Cant intubate, cant ventilate
• This Is an Emergency Call for Help
• Optimise the airway
• Position (sniffing, jaw thrust)
• Guedel airway (inspection and suction)
• Two-handed bag and mask ventilation
• Adjust or remove cricoid pressure

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Difficult intubation(cant ventilate)

• Next step?

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Difficult intubation(cant ventilate)

• Next step?
• LMA/Fast-track or another intubation attempt?

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Difficult intubation(cant ventilate)

• Next step?
• LMA/Fast-track
• How long has all this taken?
• What is the SaO2 now?
• Is the patient still asleep?

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Difficult intubation(cant ventilate)
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Difficult intubation(cant ventilate)

• SaO2 85 and falling
• Patient looks blue
• Initial tachycardia now 70 bpm and falling
• Your hands are sweaty and shaking and your heart
  is pounding
• Everybody is looking at YOU
• Surgeon wants to start got to get this baby
  out!
• NOW WHAT???

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End of the line

• Wake the patient and hope they can maintain their
  own airway/breathe
• or
• The Emergency Surgical Airway

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Time to eat!!
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Whats left?

• Obstetric haemorrhage
• Pre-eclampsia
• Neonatal resuscitation

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Obstetric haemorrhage

• Massive haemorrhage defined as gt1500 ml
• Causes
• Uterine atony
• Placental abruption
• Placenta praevia (vasa praevia)
• Ruptured uterus
• Vaginal/cervical tears
• Placental blood flow at term 500ml/min
• Clotting status (usually) unknown

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Obstetric haemorrhage

• Principles
• Requires an empty uterus to control bleeding
• Maternal compensation for blood loss may be very
  effective up to 30 blood volume
• Blood loss can be concealed/difficult to measure
  normally underestimated
• Aorto-caval compression aggravates problem
• THE MOTHER COMES FIRST

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Obstetric haemorrhage

• Principles of resuscitation GET HELP
• Oxygen
• LARGE BORE venous access x 2 - well secured
• Cross match 8 units, check FBC, UE, clotting
• Warn blood bank (may need clotting factors)
• Warm fluids and mother
• Urinary catheter

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Obstetric haemorrhage

• Uterine atony
• Syntocinon 5 IU SLOWLY
• Syntocinon infusion 10 IU/hr
• Ergometrine 0.5mg IM
• PgF2? 5mg in 500 ml saline/Misoprostil (PgE1) PR
• Manual aortic compression
• Bimanual uterine compression

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Bimanual uterine compression
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Obstetric haemorrhage

• Principles of anaesthesia
• Monitoring low threshold for arterial line
• Regional NOT appropriate 9/10
• Keep warm fluids and forced air warmer
• Care with induction doses (slow circulation time)
  /- Midazolam for awareness
• Colloid gt crystalloid NEED BLOOD EARLY
• May need coagulation products

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Obstetric haemorrhage

• Transfusion
• Monitor Hb and clotting regularly and often get
  haematologist involved early
• FFP usually required after 1 blood volume
  replacement if oozy may need platelets
• O neg appropriate early in resuscitation
• WARM WARM WARM

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Severe Pre-eclampsia

• BP gt170 mmHg systolic gt110 mmHg diastolic
• Renal proteinuria gt 300 mg/day serum
  creatinine gt 0.09 mmol/l
• Hepatic epigastric pain elevated liver
  enzymes
• Neurological persistent headache/visual
  disturbance hyper-reflexia/clonus
• Haematological thrombocytopenia DIC /
  haemolysis
• Cardiac pulmonary oedema

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Severe Pre-eclampsia

• Major risks
• Cerebral haemorrhage (20 uncontrolled
  hypertension)
• Iatrogenic fluid overload and pulmonary
  oedema/ARDS
• Eclampsia
• Failed intubation
• Foetal distress/demise

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Severe Pre-eclampsia

• BP stabilisation is critical
• Magnesium sulphate
• Hydrallazine / GTN infusion
• Avoid
• ACE inhibitors
• ß-blockers
• Invasive monitoring
• Arterial line
• CVP line

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Severe PET and GA

• Regional preferred (but not always possible)
• Increased risks of
• Airway problems (oedema)
• Haemodynamic instability
• Foetal resuscitation
• So dont do it - TRANSFER

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Severe PET and GA

• If you must do it do it carefully!!
• GET HELP
• Arterial line
• Expect and plan for difficult intubation/mask
  ventilation
• Induction modified to protect mother baby comes
  second

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Severe PET and GA

• Induction
• Thorough pre-oxygenation/preparation
• Attenuation of hypertensive response to ETT
• IV lignocaine 1mg/kg
• Alfentanyl 10 30 mcg/kg
• Fentanyl 100 200 mcg
• Magnesium sulphate 50 mg/kg if not on an infusion
  (BUT THEY SHOULD BE)
• Tell paediatrician baby may be narcotised

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Neonatal resuscitation

• Risk factors
• Pre-term/IUGR
• Meconium-stained liquor
• Difficult/complex delivery
• Multiple birth
• Maternal disease
• Bleeding
• Eclampsia
• Other
• Intra-partum narcotics

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Neonatal resuscitation

• Clamp cord
• Keep warm very important
• Place under warmer
• Dry with towel (stimulates as well)
• Assessment
• Colour and tone
• Heart rate
• Respiration
• APGAR scores

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Apgar score
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Neonatal resuscitation
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Neonatal resuscitation
Categorise into three groups

• Pink, regular respirations, heart rate gt 100/min
• Healthy baby
• Examine, wrap and give to mother

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Neonatal resuscitation

• Blue, inadequate resps, heart rate gt 100/min
• Stimulate by drying
• Airway
• Head in neutral position (folded towel behind
  shoulders)
• Open airway and clear (gentle, careful suction of
  nares and oropharynx only if having problems)
• Mouth open and jaw thrust
• Passive oxygen

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Neonatal resuscitation

• Blue, inadequate resps, heart rate gt 100/min
• Breathing assessment?

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Neonatal resuscitation

• Blue, inadequate resps, heart rate gt 100/min
• Breathing
• Colour
• Respiratory rate
• Accessory muscle use
• Nasal flaring
• Grunting
• Remains inadequate?
• Progress to lung inflation

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Neonatal resuscitation

• Blue or white, apnoeic, heart rate lt 100/min
• Needs full resuscitation ABC
• Airway - cleared as above
• Breathing
• First 4 6 breaths are inflation breaths to
  expand lungs 2 seconds at 30 40 cm H2O
• Poor compliance initially until fluid expelled
• Then ventilate 15 - 20 cm H2O _at_ 30 40 /min
• Pre-term babies more likely to need assistance
• Beware stomach inflation suction catheter into
  stomach if ventilated for more than few breaths

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Neonatal resuscitation

• Blue or white, apnoeic, heart rate lt 100/min
• Circulation
• Purpose of cardiac compressions?
• HR gt 60/min but lt 100/min and improving good
  sign of adequacy of ventilation. Continue
• HR lt 60/min chest compressions for 30 secs
• 120/min, 2 hands around chest with thumbs in
  middle of sternum. Depress 2 cm
• Reassess if HR still lt 60/min and not improving
  do drugs

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Neonatal resuscitation

• Blue or white, apnoeic, heart rate lt 100/min
• Drugs
• Adrenaline 0.1 ml/kg 110,000 IV or via ETT
• Can repeat every 3-5 mins
• Naloxone 0.1 mg/kg IM, IV, SC
• Only if history of narcotics pre-delivery
• Fluid bolus 10 ml/kg saline/colloid/blood
• Poor response to resuscitation
• Poor peripheral pulses with adequate HR
• Antepartum/intrapartum haemorrhage (very pale)
• Dextrose 10 2.5 ml/kg
• For biochemically proven hypoglycaemia (lt30
  mg/100ml)

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Neonatal resuscitation

• Other issues
• Sodium bicarbonate (2ml/kg of 4.2)
• Used late to reverse severe acidosis
• Not compatible with any other drugs inc adrenaline

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Neonatal resuscitation

• Other issues
• Sodium bicarbonate (2ml/kg of 4.2)
• Used late to reverse severe acidosis
• Not compatible with any other drugs inc
  adrenaline
• Venous access
• Umbilical vein catheters
• Standard venous cannulation
• Intra-osseous needles

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Neonatal resuscitation

• Other issues
• Sodium bicarbonate (2ml/kg of 4.2)
• Used late to reverse severe acidosis
• Not compatible with any other drugs inc
  adrenaline
• Venous access
• Umbilical vein catheters
• Standard venous cannulation
• Intra-osseous needles
• Intubation
• Prolonged resuscitation
• Meconium liquor

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Neonatal resuscitation

• Intubation
• Size of tube (uncuffed) and position at lips
• 2.5 mm _at_ 7cm lt 1 kg lt 28 wks
• 3.0 mm _at_ 8 cm 1 2 kg 28 34 wks
• 3.5 mm _at_ 9 cm 2 3 kg 34 38 wks
• 4.0 mm _at_ 9 cm gt 3 kg gt 38 wks
• Should pass into trachea easily
• Should have slight leak at 20 cm H2O

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Neonatal resuscitation

• Meconium liquor (thick)
• Before shoulders delivered
• Suction mouth, nares and pharynx thoroughly
• Immediately after cord clamped and cut
• Visualise pharynx/larynx with laryngoscope
• Suction and then intubate
• Intermittent suction on ETT as slowly withdrawn
• Repeat if significant return
• Then inflation breaths etc
• Naso/oro-gastric suction to reduce risk of
  further aspiration

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Neonatal resuscitation

• Unusual problems
• Vigorous, blue baby
• Think cyanotic congenital heart disease,
  persistent foetal circulation needs
  paediatrician ASAP transfer
• Difficult resuscitation
• Diaphragmatic hernia, pneumothorax,
• Magnesium toxicity (vasodilated, hypotensive,
  hypotonic) Calcium chloride is antidote

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Thankyou any questions?