See also
Gastroenteritis
Dehydration
Intravenous fluids
Key points
- Correction of fluid deficit, electrolyte and acid base abnormalities is the priority
- Surgical management can be delayed until the above are corrected
Background
Hypertrophic Pyloric Stenosis (HPS) usually presents between 2 and 6 weeks of chronological age with progressive non-bilious vomiting.
Risk factors include: male, first born, parental history of HPS (especially if mother affected).
Assessment
History
Vomiting:
- recurrent and progressively more forceful. May be projectile
- soon after feeding
- non-bilious
- blood stained in up to 10% of cases
- often hungry afterwards
Weight loss or inadequate weight gain
Examination
Dehydration
- Assess degree of dehydration
- Weigh and plot on growth chart with previous weights if available
Visible gastric peristalsis (may be more obvious following a feed)
Pyloric mass
- Located in the right upper quadrant at the lateral edge of the rectus abdominis muscle
- Best felt from the left side with the infant settled and supine
- May be difficult to palpate. May require repeated examinations or to wait for several minutes with hand on abdomen to feel
Differential diagnoses:
Urinary tract infection (UTI), gastroenteritis, gastrooesophageal reflux, surgical causes (eg volvulus, malrotation), congenital adrenal hyperplasia
Management
Investigations
- Capillary or venous blood gas with electrolytes and glucose
- Hypochloraemic hypokalaemic metabolic alkalosis may be seen – the degree of abnormality is proportionate to the duration of symptoms prior to presentation
- Abdominal ultrasound can be used to investigate if the diagnosis is not established clinically (95% sensitive in the diagnosis of HPS)
- Urine microscopy and culture to rule out UTI
Treatment
- Gain IV access
- Stop oral feeds
- Insert a nasogastric tube if profuse vomiting continues despite stopping feeds
Fluid Management
| Purpose |
Fluid |
Notes |
| Resuscitation |
0.9% Sodium Chloride |
Fluid Resuscitation as required. Not all infants will require fluid resuscitation |
| Deficit |
1000 mL 0.9% Sodium Chloride + 5% Glucose |
Refer to dehydration and IV fluids guidelines.
Include Potassium in IV fluids once urine output is adequate (1–2 mL/kg/hr) |
| Maintenance (ongoing) |
1000 mL 0.9% Sodium Chloride + 5% Glucose |
- Surgical correction of HPS is usually delayed until correction of dehydration, acid / base status and electrolyte disturbances
- It is particularly important to fully correct serum bicarbonate before surgery because of the risk of hypoventilation / apnoea post-operatively in the setting of a metabolic alkalosis
Monitoring and management
- Repeat blood gas with electrolytes 6 hourly initially and adjust fluids accordingly
- Usually aim to fully correct fluid and electrolyte deficits within 48 hours
- Blood bicarbonate levels can be used to monitor response to fluid therapy in HPS (therefore Plasmalyte is not used in the management of HPS as it contains bicarbonate precursors that may affect this process)
Consider consultation with local paediatric team when
Pyloric stenosis suspected — all
confirmed cases should be managed as an inpatient
Note: consult with a paediatric surgeon
Consider transfer when
Confirmed or high suspicion for pyloric stenosis
Note: transfer to a paediatric centre early, once an
initial management plan is in place
For emergency advice
and paediatric or neonatal ICU transfers, see Retrieval Services.
Consider discharge when
- Cleared by surgical team
- Tolerating full oral feeds
- Pain free
Parent information sheet
Pyloric Stenosis
Last updated July 2019