Abdominal pain

Any person, 16 years and over, who presents with abdominal pain or discomfort.

History prompts, signs and symptoms

These are not exhaustive lists. Maintain an open mind and be aware of cognitive bias.

Red flags

Recognise: identify indicators of actual or potential clinical severity and risk of deterioration.

Respond: carefully consider alternative ECAT protocol. Escalate as per clinical reasoning and local CERS protocol, and continue treatment.

Clinical assessment and specified intervention (A to G)

If the patient has any Yellow or Red Zone observations or additional criteria (as per the relevant NSW Standard Emergency Observation Chart), refer and escalate as per local CERS protocol and continue treatment.

Position

Assessment	Intervention
Observe general position patient able to lie or sit still guarding pacing	Position of comfort

Airway

Assessment	Intervention
Patency of airway	Maintain airway patency Consider airway opening manoeuvres and positioning

Breathing

Assessment	Intervention
Respiratory rate and effort Consider auscultation of chest (breath sounds) Oxygen saturation (SpO2)	Assist ventilation as clinically indicated Consider oxygen if dyspnoeic, titrate oxygen to maintain SpO2 over 93% Patients at risk of hypercapnia, maintain SpO2 at 88–92%

Circulation

Assessment	Intervention
Perfusion (capillary refill, skin warmth and colour) Pulse Blood pressure (initial BP includes both arms) Cardiac rhythm	Assess circulation Attach cardiac monitor and complete 12 lead ECG if BP/HR are within the Yellow or Red Zones, or where clinically relevant, e.g. irregular pulse, palpitations, syncope, shock, respiratory compromise, cardiac history or clinical concern
IVC and/or pathology	Insert IV cannula, if trained and clinically indicated If unable to obtain IV access, consider intraosseous, if trained See pathology section
Signs of shock: tachycardia and CRT 3 seconds and over and/or abnormal skin perfusion and/or hypotension	If signs of shock present and/or SBP less than 90 mmHg, give 250 mL of sodium chloride 0.9% IV/intraosseous bolus Repeat every 10 minutes (up to 1000 mL) until SBP over 90 mmHg or signs of shock have resolved

Disability

Assessment	Intervention
ACVPU	If ACVPU shows reduced level of consciousness, continue to GCS, pupillary response and limb strength
GCS, pupillary response and limb strength	Obtain baseline and repeat assessment, as clinically indicated
Pain	Assess pain. If indicated, give early analgesia as per analgesia section then resume A to G assessment

Exposure

Assessment	Intervention
Temperature	Measure temperature
Skin inspection, including posterior surfaces	Check and document any abnormalities

Fluids

Assessment	Intervention
Hydration status: last ate, drank, bowels opened, passed urine or vomited	Commence fluid balance chart as required
NBM	Consider clear fluids or NBM based on red flags and clinical severity
Nausea and/or vomiting	If present, see nausea and/or vomiting section
Gastrointestinal	Commence stool chart If ostomy bag present, observe functioning and activity levels

Glucose

Assessment

Intervention

BGL

Measure BGL If BGL less than 4 mmol/L with NO decrease in level of consciousness (Yellow Zone criteria): give quick-acting carbohydrate: sugary soft drink, fruit juice or 40% glucose gel, up to 15 g, buccal reassess BGL in 15–30 minutes and repeat treatment until BGL over 4 mmol/L If BGL less than 4 mmol/L WITH a decrease in level of consciousness (Red Zone criteria) OR the patient is unable to tolerate oral intake: give 40% glucose gel, up to 15 g, buccally in incremental doses, as tolerated, while establishing IV access give 10% glucose 200 mL by IV infusion over 15 minutes, once only if delay in IV access, give glucagon 1 mg IM, once only reassess BGL in 15 minutes If the patient is unconscious or peri-arrest: give 50% glucose 50 mL by slow IV injection, once only. Use with caution as extravasation can cause necrosis if delay in IV access, give glucagon 1 mg IM, once only reassess BGL in 15 minutes Once stabilised, give patient long-acting carbohydrate and continue to check BGL hourly, or as clinically indicated

Focused assessment

Complete an abdominal focused assessment.

Precautions and notes

• Assessment of abdominal pain is complex, therefore maintain a high index of suspicion for differential conditions. Be aware of cognitive bias, focus on excluding red flags and early escalation.
• Opioid analgesics can be safely given before full assessment and diagnosis in acute abdominal pain without increasing the risk of diagnostic errors. Ensure appropriate monitoring post administration, particularly in the elderly.
• Consider abdominal aortic aneurysm (AAA) in any patient aged over 50 years who presents with abdominal, flank or back pain:
  • Complete initial blood pressure on both arms. More than 20 mmHg difference between arms is abnormal. This can be an indicator of aortic dissection.
  • The symptoms of a ruptured AAA may mimic renal colic, diverticulitis or gastrointestinal haemorrhage.
• Elderly patients presenting with abdominal, loin or flank pain have a 14% mortality rate. Symptoms may be vague with low tolerance for shock. For example, an SBP of 90 mmHg may be critical if previously hypertensive.
• Consider gynaecological causes:
  • Ectopic pregnancy – a medical emergency that can present as abdominal pain in early pregnancy
  • Pregnancy in all females of childbearing age
  • Ovarian torsion.
• Complete a testicular examination if the cause of pain is unclear, or in the presence of scrotal pain or swelling. Suspected testicular torsion requires urgent escalation as per local CERS protocol. Delays in surgical management may result in testicular loss.

Interventions and diagnostics

Specific treatment

Treatment for abdominal pain will depend on the diagnosis.

Analgesia and/or nausea management should be offered to all patients.

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Analgesia

Select pain score:

• 1–3 (mild)
• 4–6 (moderate)
• 7–10 (severe)

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Nausea and/or vomiting

If nausea and/or vomiting is present, give:

• ondansetron 4 mg orally or IV/IM. If symptoms persist after 60 minutes, repeat once, maximum dose 8 mg
• or prochlorperazine 5 mg orally once only or 12.5 mg IV/IM once only

Choice of antiemetic should be determined by cause of symptoms.

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Thiamine

If patient is experiencing alcohol withdrawal, or is at high risk of thiamine deficiency (e.g. those who drink large amounts of alcohol or who are severely malnourished), then:

• monitor using alcohol withdrawal scale
• give thiamine 300 mg IV/IM once only

If hypoglycaemic: thiamine should be given before glucose, or as soon as possible. Glucose can further deplete thiamine stores and precipitate Wernicke encephalopathy.

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Radiology

Radiology will depend on the working diagnosis. It needs to be requested by a medical or nurse practitioner. If there is concern for urgent radiology, escalate as per local CERS protocol.

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Pathology

• FBC, UEC
• Urinalysis: mid-stream (preferred), clean catch or catheter urine. If positive for nitrites and/or leucocytes send for MC&S. Keep sample refrigerated if transport delayed
• Female of childbearing age: urine βHCG. If positive and within the first trimester, send serum βHCG for quantitative analysis
• Hypovolemia: VBG, if available
• RUQ or epigastric pain: LFT, lipase
• Cardiac considerations: troponin
• History of alcohol abuse: LFT, lipase
• Warfarinised: INR
• Temp less than 35°C or 38.5°C and over: take two sets of blood cultures from two separate sites

Medications

The shaded sections in this protocol are only to be used by registered nurses who have completed the required education.

Medications with contraindications or requiring dose adjustment are marked:

• ^H for patients with known hepatic impairment
• ^R for patients with known renal impairment.

Escalate to medical or nurse practitioner.

Evidence informed	Information was drawn from evidence-based guidelines and a review of latest available research. For more information, see the development process.
Collaboration	This protocol was developed by the ECAT Working Group, led by the Agency for Clinical Innovation. The group involved expert medical, nursing and allied health representatives from local health districts across NSW. Consensus was reached on all recommendations included within this protocol.
Currency	Due for review: Jan 2026. Based on a regular review cycle.
Feedback	Email ACI-ECIs@health.nsw.gov.au