Overview #
Key points
- Early referral to surgery if suspicious of urgent surgical causes, or if unsure about the diagnosis
- Ectopic pregnancy should be excluded in all females of childbearing age
- Testicular torsion should be excluded in males with acute lower abdominal pain
- Abdominal aortic aneurysm should be excluded in elderly patients, especially if the history is non-specific
- Incarcerated femoral hernia is a red flag that is often missed in elderly female patients
- Consider referred pain from extra-abdominal causes
Triage #
The patient should be seen urgently if the pain is severe, radiating to the back or shoulder tip, associated with cardiorespiratory symptoms or abnormal vital signs. In the absence of red flags, the patient may be seen within an hour or as determined by the triage nurse (if applicable).
Causes #
Upper abdominal pain (1,2)
| Right upper quadrantCholelithiasisAcute cholecystitisAscending cholangitisAcute hepatitisPerforated duodenal ulcer | EpigastricGastritisPeptic ulcer diseaseGORDPancreatitis (acute, chronic)Gastric cancerPancreatic cancer | Left upper quadrantGastritisPeptic ulcer diseaseSplenomegalySplenic ruptureSplenic infarction |
| Extra-abdominal causesPneumoniaPulmonary embolismMyocardial ischaemia |
Central or diffuse abdominal pain (1,2)
| GI causesGastroenteritisBowel obstructionBowel perforationEarly appendicitisMesenteric ischaemiaInflammatory bowel diseaseCoeliac diseaseIrritable bowel syndromeColorectal cancerPeritonitis | Non-GI causesAbdominal aortic aneurysmDiabetic ketoacidosisHypercalcaemiaAdrenal insufficiencySickle cell crisis |
Lower abdominal pain (1,2)
| Right lower quadrantAppendicitisMeckel’s diverticulumMesenteric adenitisInflammatory bowel disease (terminal ileitis)Colorectal cancerInfectious colitisNephrolithiasisPyelonephritisPsoas abscessInguinal herniaFemoral hernia | SuprapubicCystitisAcute urinary retentionInflammatory bowel diseaseColorectal cancerInfectious colitis | Left lower quadrantDiverticulitisInflammatory bowel diseaseColorectal cancerInfectious colitisNephrolithiasisPyelonephritisPsoas abscessInguinal herniaFemoral hernia |
| Gynaecological, pregnancy-related or testicularEctopic pregnancyOvarian torsionRuptured ovarian cystEndometriosisPelvic inflammatory diseasePlacental abruptionTesticular torsion |
Clinical features #
Key points
- Alvarado scores may be used to assess the likelihood of acute appendicitis without imaging (3)
- Alvarado scores ≤3: 96.2% sensitivity for not having appendicitis, imaging is not recommended
- Alvarado scores ≥7: 77% sensitivity for appendicitis
- Acute cholecystitis cannot be reliably diagnosed from clinical features alone (4)
- Right upper quadrant tenderness: negative LR of 0.4
- Murphy’s sign: positive LR of 2.8
- For patients with suspected ascending cholangitis, Tokyo Guidelines {mdcalc link} may be used for clinical diagnosis and severity grading (5)
History (1)
| Time courseSudden onset (perforated hollow viscus, urolithiasis, PE, ruptured ectopic pregnancy, ovarian/testicular torsion)Over hours to days (appendicitis, UTI)Constant (inflammatory) vs intermittent (hollow viscus obstruction)SitePain radiating to the back (pancreatitis, AAA, posterior peptic ulcer)Migratory pain (appendicitis, urolithiasis)Shoulder tip pain (diaphragmatic irritation from free gas, blood or pus)Aggravating factorsMovement (surgical causes, peritonitis)Posture (pancreatitis)Independent of posture, unable to sit comfortably (urolithiasis, biliary colic)Associated featuresConstipation (bowel obstruction), diarrhoea (gastroenteritis, IBD)GI bleeding (peptic ulcer, IBD)N/V (pancreatitis, bowel obstruction), assess oral tolerance (dehydration)History of AF and peripheral vascular disease (mesenteric ischaemia)File review – Recent operations, anticoagulation | |
| Upper abdomenAssociation with food (peptic ulcer, biliary colic)Obstructive jaundice (choledocholithiasis, ascending cholangitis)Cardiorespiratory symptoms (MI, PE)NSAIDs use (peptic ulcer) | Lower abdomenUrinary symptoms (UTI, urolithiasis)Gynaecological – Menstrual changes (ectopic pregnancy), antepartum haemorrhage (abruption) |
Examination (1,2)
- Vitals, ABCDE
- Abdominal exam
- Jaundice
- Signs of peritonism – guarding, rigidity, rebound tenderness
- Murphy’s sign (Sn 65%, Sp 87%) (4)
- Abdominal aorta – check in elderly patients
- Bowel sounds
- Signs of dehydration
- Inguinoscrotal exam – if suspecting hernias, or to identify testicular torsion in males with acute lower abdominal pain
- DRE – especially for GI bleeding or suspected obstruction; not required for localised upper abdominal pain, or if likely a non-GI cause
- Pelvic examination – consider in all females with acute lower abdominal pain and no clear alternative explanation
Investigations #
Initial investigations (1,2)
| Investigation | Significance |
| FBE | Low Hb in peptic ulcer, GI malignancy; WCC for inflammation |
| CRP | Inflammation |
| UEC | Dehydration due to oral intolerance |
| VBG | Quick results for Hb, electrolytes, lactate and glucoseElevated lactate in shock and mesenteric ischaemia, significant if >2 mmol/L |
| Glucose | Hyperglycaemia in DKA (check for metabolic acidosis and ketones) |
| Urine HCG | Exclude ectopic pregnancy in all females of childbearing age |
| Urine dipstick | UTI. Microscopic haematuria is sensitive for urolithiasis |
Further investigations (1,2)
| Investigation | Indication |
| ECG | If epigastric pain and cardiovascular risk factors. Confirms AF in patients with mesenteric ischaemia |
| Troponin | If epigastric pain and cardiovascular risk factors |
| LFTs | If upper or mid abdominal pain, jaundice |
| Lipase | If upper or mid abdominal pain |
| Calcium | Symptoms of hypercalcaemia (“stones, bones, psychic moans”), history of malignancy, diffuse or nonspecific abdominal pain |
| X-ray | If suspecting bowel obstruction or perforation (supine and erect AXR, and erect CXR) |
| #Ultrasound | If suspecting a biliary, pancreatic, splenic, urinary tract, AAA or gynaecological pathology |
| #CT | Consider in elderly or unwell patients with diagnostic uncertainty. CTA for intra-abdominal bleeding, GI ischaemia |
Management #
- Primary assessment (ABCDE) – Consider urgent escalation if the patient is unstable
- Consider surgical referral in patients with the following (1):
- Abnormal vital signs
- Severe or ongoing symptoms
- Signs of peritonism
- Significant abnormalities on investigation results
- Risk factors e.g. history of peptic ulcer or gallstones
- Recent abdominal surgery
- Diagnostic uncertainty
- IV fluids for patients with dehydration or poor oral intake – see “Fluids” {link to chapter}
- Pain management (6,7)
| Mild pain | Paracetamol immediate-release 1 g orally, 4-to 6-hourly. Maximum dose 4 g in 24 hoursAND Ibuprofen 200-400 mg orally, TDSAvoid in peptic ulcer, GI bleeding, GORD, or if CrCl <25 mL/minute |
| Moderate pain | Paracetamol immediate-release 1 g orally, 4-to 6-hourly. Maximum dose 4 g in 24 hoursAND Ibuprofen 200-400 mg orally, TDSAvoid in peptic ulcer, GI bleeding, GORD, or if CrCl <25 mL/minuteAND Oxycodone immediate-release 5-10 mg orally, 4-hourly if requiredIf older than 75 years, dose adjust: 2.5-5 mg orally |
| Severe pain | Paracetamol immediate-release 1 g orally, 4-to 6-hourly. Maximum dose 4 g in 24 hoursAND Ibuprofen 200-400 mg orally, TDSAvoid in peptic ulcer, GI bleeding, GORD, or if CrCl <25 mL/minuteAND Oxycodone immediate-release 5-15 mg orally, 2-hourly if requiredIf age 70 to 85 years, dose adjust: 5-10 mg orallyIf older than 85 years, dose adjust: 2.5-5 mg orally |
| Severe pain and Nil by mouth | Paracetamol 1 g IV 6 hourlyAND #Morphine 2-5 mg IV for the first dose, then 1-2 mg IV for subsequent doses if inadequate relief after 5 minutesDiscuss with senior clinician regarding hospital-specific dosingFor adults who are frail or cachectic, or older than 69 years: 1-2 mg IV for the first dose, 0.5-1 mg IV for subsequent dosesMay only give subsequent doses if patient is easy to rouse, remains awake, respiratory rate ≥8 |
- Antiemetics (if nauseous) – avoid metoclopramide if suspecting GI obstruction or perforation (8,9)
| Ondansetron 4-8 mg IV or orally 8- to 12-hourlyPrecautions – Do not exceed 8 mg daily in severe hepatic impairment |
- Treat underlying cause (discuss with senior clinician)
References #
1. Hayes J. Abdominal pain. In: Hayes J. Title: Northern Hospital guidelines. Melbourne: Northern Hospital; 2018.
2. Penner R, Fishman M. UpToDate [Internet]. Uptodate.com. 2021 [cited 2 October 2021]. Available from: https://www.uptodate.com/contents/evaluation-of-the-adult-with-abdominal-pain
3. McKay R, Shepherd J. The use of the clinical scoring system by Alvarado in the decision to perform computed tomography for acute appendicitis in the ED. The American Journal of Emergency Medicine. 2007;25(5):489-493.
4. Trowbridge R, Rutkowski N, Shojania K. Does This Patient Have Acute Cholecystitis?. JAMA. 2003;289(1):80.
5. Takada T. Tokyo Guidelines 2018: updated Tokyo Guidelines for the management of acute cholangitis/acute cholecystitis. Journal of Hepato-Biliary-Pancreatic Sciences. 2018;25(1):1-2.
6. Severe, acute nociceptive pain [Internet]. eTG Complete. 2020 [cited 3 October 2021]. Available from: https://www.tg.org.au
7. Moderate, acute nociceptive pain [Internet]. eTG Complete. 2020 [cited 3 October 2021]. Available from: https://www.tg.org.au
8. Nausea and vomiting [Internet]. eTG Complete. 2016 [cited 3 October 2021]. Available from: https://www.tg.org.au
9. Australian Medicines Handbook [Internet]. AMH. 2021 [cited 2 October 2021]. Available from: https://amhonline.amh.net.au/
Contributors
Reviewing Consultant/Senior Registrar
Dr Cheng Xie
Dr Tsung Chung
