Pyloromyotomy

 

Main thing:

·         The emergency is medical

·         The definitive treatment is surgical

 

Pathophysiology:

Causes

·      Gastric losses

·      Starvation

Problems

1.    ↓Volume -> lactic acidosis

2.    ↑Tonicity -> not sure

3.    ↑pH -> respiratory depression

4.    Electrolyte disturbance -> arrhythmia

Priorities

1.    Volume

2.    Tonicity

3.    pH

4.    Electrolytes

It’s the same for the body as it is for us

Hence the kidney worsens alkalosis for the sake of preserving volume

Metabolic profile

·      ↓pH

·      ↓Na

·      ↓Cl

·      ↓K

·      ↓BSL

Hormonal profile

·      ↑Renin-angiotensin-aldosterone

·      ↑ADH

 

Fluid assessment:

Mild (1-3%)

·      Thirsty

·      Dry mouth

Moderate (4-6%)

·      Slow cap refill

·      Oliguria

·      Grumpy

Severe (7%+)

·      Very slow cap refill

·      Anuria

·      Tachycardia, hypotension

·      Rag doll

 

Anaesthesia: pyloric stenosis

Resuscitation

Treatment:

·      Boluses: 20mL/kg 0.9% NaCl over 30 mins

·      Maintenance: 4-2-1 rule (plasmalyte? 4% glucose + 0.18% NaCl?)

Goals:

·      Back to normal weight (if known)

·      Euvolaemia (UO 0.5mL/kg/h – note surgery, stress, oliguria)

·      Cl- >105

·      HCO3 <30

Induction

·      Large bore orogastric tube + four quadrant suction

·      Folded towel under the shoulders

·      Pre-oxygenate

·      IV induction ± bag-mask ventilation

·      Atropine + propofol + suxamethonium + sevoflurane

·      MAC 1, size 3.5 coETT

·      Check ETT position and cuff pressure

Post-op care

·      Risk of apnoea: 12 hour line of sight monitoring

·      Analgesia: just local anaesthetic + paracetamol (avoid opioid)

·      Fluid: 100mL/kg/day until feeding normally

 

Anaesthesia: neonate

Airway

·      Small and easily obstructed

·      BMV: keep mouth open, don’t press on neck

·      LMA: only as a get-out-of-jail card

·      ETT: towel under the shoulders, check cuff pressure

Breathing

·      Rapid desaturation when apnoeic

·      Oxygenation highly PEEP-dependent

·      Risk of oxygen toxicity

·      Risk of post-op apnoea

Circulation

·      Hypoxia causes bradycardia

·      Fairly fixed stroke volume

Drugs

·      High risk of drug dose error

·      High risk of significant air embolism

·      Variably slower rate of metabolism

External

·      Get cold very quickly when exposed

·      Hypothermia causes apnoea

Fluids

·      Get dehydrated quickly when exposed

·      Easy to flood (2 x normal saline ampoules = 10mL/kg)

Glucose

·      Get hypoglycaemic quickly when not fed

Haemoglobin

·      Visually small blood loss may be significant

 

 

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