Rapid review: surgery and emergency medicine

• This page is a revision map for the emergency presentations a medical student is expected to recognise and start managing before senior help arrives: acute abdomen, major trauma, head injury, burns, shock, postoperative fever, hernias, vascular emergencies, breast and thyroid lumps, poisoning, anaphylaxis and cardiac arrest.
• Each block gives the picture in plain clinical words, the single most likely diagnosis for that picture, the best first test, the best first treatment, the commonest wrong answer and where to read the full topic page.
• These are high-stakes, time-critical problems. The aim is to get the first minutes right: airway, breathing, circulation, then the diagnosis-specific step.
• Where guidelines disagree, the value used is named as an edition and the source is cited next to it.
• Read the linked full topics for depth; this page does not replace them.

By the end of this page you should be able to:

1. State, for each named presentation, the most likely diagnosis, the best first test and the best first treatment.
2. Run a trauma primary survey in the correct order and explain what must not be done.
3. Recognise the red flags that convert a stable patient into an emergency call.
4. Use at least one structured algorithm and one comparison table while revising.
5. Pass a mixed check-yourself quiz covering these presentations.

Read each block as a mini clinical vignette. Cover the answer column in your mind before reading it, then check. The diagnosis given is the single most likely one for that picture; the full topic explains the differential and why it is so.

The figures and depths you need for exams live in the full topics, which are listed in plain text at the end of each block. The references are the editions actually used; they can be opened by their URL.

Presenting picture. Sudden or worsening abdominal pain, often with nausea, vomiting and distension. The patient lies still (peritonitis) or writhes (colic). Older patients may have little pain despite serious disease.

Single most likely diagnosis for the pattern. For pain that begins centrally and migrates to the right lower quadrant, appendicitis is the single most likely diagnosis. For an elderly patient with sudden central pain and collapse, think ruptured abdominal aortic aneurysm.

Best first test. Tailor the test to the suspected cause rather than to a fixed panel: erect chest radiograph and supine abdominal radiograph when obstruction or perforation is suspected; serum lactate and venous blood gas for ischaemia; pregnancy test in any woman of childbearing age; and cross-sectional imaging, usually CT with intravenous contrast, when the diagnosis remains unclear or the patient is deteriorating. A complete blood count, renal function and amylase or lipase are routine.

Best first treatment. Keep the patient nil by mouth, give intravenous crystalloid resuscitation guided by perfusion, control pain and nausea, give appropriate analgesia, and start broad-spectrum intravenous antibiotics when infection or a suspected surgical source is present. Suspected perforation, strangulation, ischaemia or ruptured aneurysm goes to theatre without waiting for complete investigation.

Commonest wrong answer. Treating the pain with a strong analgesic and then discharging before considering gynaecological causes, ischaemic bowel or an atypical myocardial infarction in an older patient; or starting antibiotics and fluids but failing to act on a rigid, silent abdomen.

Full topic page. surgery/acute-abdomen, linked with emergency-medicine/abdominal-examination-and-presentation.

Presenting picture. A patient after a high-energy mechanism, or any multisystem injury. The mechanism, speed and whether they are alert all matter before the patient can tell you anything.

Single most likely problem to treat first. Airway obstruction and loss of it, with cervical spine protection, is the first threat to life. Tension pneumothorax comes next, then uncontrolled haemorrhage.

Best first test. Whole-body CT with intravenous contrast (pan-scan) once the patient is stable enough to move to the scanner; before that, bedside ultrasound (focused assessment with sonography in trauma, FAST) and plain chest radiograph, or extended FAST, look for free fluid, pneumothorax and pericardial fluid. Laboratory screening includes full blood count, group and save or crossmatch, clotting and lactate.

Best first treatment. Run the survey in the fixed order of airway, breathing, circulation, disability and exposure; immobilise the cervical spine; give oxygen; control external bleeding directly; open a tension pneumothorax with open thoracostomy then a chest drain, as NICE NG39 advises ^[2]; obtain two large lines; and in hospital do not use crystalloids for active bleeding, replacing volume instead with blood components at a 1:1 ratio of plasma to red cells for adults aged 16 or over ^[2]. Defer definitive operations until physiology is restored if the patient is in extremis.

Commonest wrong answer. Abandoning the sequence to chase a long-bone fracture or a head scan in an unstable patient, or pouring in crystalloid for an actively bleeding patient.

Full topic page. emergency-medicine/trauma-primary-survey.

Presenting picture. Any blow to the head with confusion, amnesia, vomiting, headache or loss of consciousness. Severity is stratified by the Glasgow Coma Scale, imaging findings and risk factors, not by how dramatic the event looked.

Single most likely severe condition to exclude. An acute intracranial haematoma requiring neurosurgical evacuation, most often an extradural or acute subdural collection, sometimes with secondary brain injury.

Best first test. CT of the head. NICE NG232 advises a CT head scan within 1 hour of identifying any of the listed high-risk factors in adults aged 16 or over, and within 8 hours when there has been some loss of consciousness or amnesia and further risk factors are present ^[1]. A trained member of staff should assess anyone presenting to an emergency department within a maximum of 15 minutes of arrival ^[1].

Best first treatment. Protect the airway, keep the cervical spine immobilised, control blood pressure and prevent secondary brain injury while deciding on imaging. Give tranexamic acid as soon as possible and within 2 hours of the injury, before imaging, where the guideline applies ^[1]. Escalate to neurosurgery promptly for a deteriorating conscious level, a significant collection or a base-of-skull fracture.

Commonest wrong answer. Relying on the fact that the patient is drunk or has a normal initial examination, or forgetting that a deteriorating Glasgow Coma Scale after a lucid interval is an intracranial haematoma until proved otherwise.

Full topic page. emergency-medicine/head-injury.

Presenting picture. A thermal, chemical, electrical or scald injury, with pain, erythema or blistering, airway soot or a hoarse voice, and tachypnoea. The burn looks small but the patient looks shocked, so think inhalation and fluid loss.

Single most likely immediate threat. Inhalation injury and upper-airway oedema, followed by hypovolaemic shock from capillary leak. Facial burns or a closed-space fire make this likely even when the skin burn is modest.

Best first test. There is no single early laboratory test; the clinical survey is the test. Arterial blood gas with carboxyhaemoglobin in suspected smoke or inhalation injury, electrocardiogram in electrical injury, and a formal assessment of total body surface area involved and burn depth. A chest radiograph is often delayed and initially normal.

Best first treatment. Secure the airway early when inhalation is suspected, before oedema makes it impossible. Apply the ABCDE survey, give high-flow oxygen if carbon monoxide is a concern, and cool a freshly burned area with running water for at least 20 minutes ^[7]. Cover the wound in clean cling film or a sterile non-adherent dressing, keep the patient warm to avoid hypothermia, then calculate resuscitation fluids and refer according to burn size and location.

Commonest wrong answer. Icing the burn, applying butter or creams, or delaying cooling because the patient is already cold; also forgetting to inspect the back and perineum.

Full topic page. emergency-medicine/burns.

Presenting picture. A collapsed or confused patient with tachycardia, hypotension, poor peripheral perfusion, reduced urine output and a lactate that is rising. The type of shock is decided by the cause and the examination, not by the monitor.

Single most likely type for the setting. In a medical patient with infection and no obvious bleeding, septic shock is the most likely; in trauma, hypovolaemic shock from haemorrhage; in a patient with a trigger and stridor or wheeze, anaphylactic; after a large myocardial infarction, cardiogenic.

Best first test. Bedside echocardiography or a structured focused ultrasound (heart and inferior vena cava) to separate hypovolaemia, pump failure and obstruction, plus serial lactate, central line or arterial line measurements and the search for a source: urine, chest radiograph, blood cultures and appropriate imaging.

Best first treatment. Treat the mechanism, not just the pressure. Hypovolaemic bleeding gets source control and blood products rather than crystalloid ^[2]. Cardiogenic shock needs the cause lifted (reperfusion for acute coronary syndrome, afterload reduction where safe) and organ support. Septic shock needs prompt source control and antibiotics with fluids directed by perfusion ^[6]. Anaphylactic shock gets intramuscular adrenaline, below. Obstructive shock (tension pneumothorax, tamponade, massive pulmonary embolism) needs the obstruction relieved urgently before any fluid challenge settles the matter.

Commonest wrong answer. Giving a universal fluid bolus to a patient in cardiogenic or obstructive shock and assuming the problem is volume depletion.

Full topic page. emergency-medicine/shock.

Presenting picture. Fever in the first few days after an operation, with wound tenderness, cough, dysuria, limb swelling or abdominal pain depending on the day. The classic teaching groups causes into wound infection, urinary infection, chest infection, deep vein thrombosis and drug fever.

Single most likely cause early after surgery. In the early postoperative period, atelectasis and chest infection dominate; by the middle of the first week wound infection is commoner; fever late in the stay should raise deep venous thrombosis or pulmonary embolism.

Best first test. A focused search rather than a blanket panel: inspect the wound and drain sites, measure oxygen saturation and auscultate the chest, dipstick and send urine, examine the calves and listen to the abdomen, with a full blood count and C-reactive protein. A raised white cell count with wound erythema or a leaking wound points to surgical site infection, which is the infection defined in NICE NG125 as local inflammatory signs plus systemic fever ^[5]. Add blood cultures when the patient is unwell.

Best first treatment. Treat the cause that the examination finds: encourage physiotherapy and coughing, give analgesia to allow deep breathing, change or remove the urinary catheter and review antibiotics, open and drain an infected wound rather than starting antibiotics alone, and anticoagulate while imaging is arranged when venous thromboembolism is suspected. Escalate immediately for sepsis or a leaking anastomosis.

Commonest wrong answer. Starting a broad antibiotic for every postoperative fever without examining the wound, the chest and the urine, or assuming fever after day 5 is just a virus.

Full topic page. surgery/postoperative-complications.

Presenting picture. A lump that appears on straining or standing and reduces when the patient lies flat; groin or midline; may become painful, irreducible or discoloured. Ask about change in size, reducibility and the last time the patient could push it back.

Single most likely dangerous variant. A strangulated hernia, in which the blood supply to the contained bowel is compromised and progresses to gangrene within hours.

Best first test. The diagnosis is clinical for most groin hernias. When the diagnosis is uncertain, the lump is in the midline or signs of obstruction are present, request an abdominal radiograph and, increasingly, a CT scan of the abdomen to look for obstruction, strangulation and the contents of the sac.

Best first treatment. Reduce a simple irreducible hernia if it is safe to try, or plan elective repair. An incarcerated or strangulated hernia, or any hernia with obstruction or peritonitis, is a same-day surgical emergency: resuscitate, pass a nasogastric tube when obstructed, and operate. Guidelines for emergency ventral and incisional hernia repair also favour a damage-control mindset, restoring physiology before definitive reconstruction, and mesh-based repair for defects that close under physiologically stable conditions ^[10].

Commonest wrong answer. Repeatedly trying to reduce a tense, painful hernia in a vomiting patient and then watching it overnight; or missing a femoral hernia in an older woman.

Full topic page. surgery/hernias.

Presenting picture. Three frequent ones: a pulsatile expansile abdominal mass or sudden back or abdominal pain with collapse; a cold, pale, painful leg that loses pulses; and a swollen, tender calf or sudden breathlessness with pleuritic chest pain. Each is an emergency for a different reason.

Single most likely diagnosis. A ruptured abdominal aortic aneurysm in the collapsed patient with abdominal or back pain; acute arterial occlusion in the cold leg; pulmonary embolism in the breathless patient with risk factors. For a ruptured aneurysm, NICE NG156 reminds clinicians to think about the diagnosis with new abdominal or back pain, cardiovascular collapse or loss of consciousness, because it is more likely with the risk factors listed, including smoking, COPD, hypertension, atherosclerosis and family history ^[3]. Aortic ultrasound is the first test and 5.5 cm or more is the threshold for referral to vascular services ^[3].

Best first test. Bedside aortic ultrasound in suspected ruptured aneurysm; urgent CT angiography if the patient is stable enough; ankle-brachial pressure index and duplex ultrasound for the leg; CT pulmonary angiography or a ventilatio-perfusion scan for pulmonary embolism; D-dimer only when the clinical probability is low. A threatened limb needs no imaging before anticoagulation and revascularisation.

Best first treatment. Ruptured aneurysm: permissive hypotension, blood products and immediate vascular control. Acute limb ischaemia: immediate anticoagulation with unfractionated heparin and urgent revascularisation, with fasciotomy if a compartment syndrome develops. Pulmonary embolism with shock: systemic thrombolysis then anticoagulation. Suspected aortic dissection or large aneurysm not yet ruptured goes to vascular services without delay.

Commonest wrong answer. Waiting for a scan in a collapsed patient who is exsanguinating from a ruptured aneurysm, or calling a cold pale foot vasculitis or neuropathy.

Full topic page. vascular/abdominal-aortic-aneurysm and vascular/acute-limb-ischaemia.

Presenting picture. A breast lump noticed by the patient or on screening: painless, hard, irregular and fixed lumps, skin dimpling, nipple changes or discharge; and an anterior neck lump that moves with swallowing. Age, speed of growth and associated features guide the diagnosis.

Single most likely benign and single most likely serious cause. Breast: a fibroadenoma or cyst in a young woman, but breast cancer must be excluded in anyone aged 30 or over with an unexplained breast lump, or with skin changes suggestive of cancer, by a suspected cancer pathway referral ^[4]. Thyroid: a colloid or degenerative nodule, but an unexplained thyroid lump warrants consideration of a suspected cancer pathway referral ^[4].

Best first test. Breast: clinical examination followed by imaging that matches age (ultrasound in younger women, mammography in older women) and a core needle biopsy when suspicious: the standard triple assessment. Thyroid: serum thyroid-stimulating hormone, then neck ultrasound with cytology by fine-needle aspiration, reported using the Bethesda categories, when the ultrasound appearance or clinical features suggest it.

Best first treatment. Excision of a symptomatic fibroadenoma or drainage of a cyst; multimodality treatment by stage for confirmed breast cancer; for thyroid, most nodules are observed, while suspicious or malignant lesions receive surgery, with radioactive iodine and thyrotropin suppression added by guideline.

Commonest wrong answer. Reassuring a patient aged over 30 with a new breast lump after a single normal ultrasound, or watching a hard, fixed neck lump month after month without cytology.

Full topic page. breast/breast-examination-and-presentation and endocrine/thyroid-protocols.

Presenting picture. A collapsed, drowsy or confused patient after ingestion, inhalation or injection, sometimes with pill bottles, needles, the smell of solvents, miosis, tachycardia, sweating or the classic toxidromes. Co-ingestion and delayed presentations are common.

Single most likely mechanism of harm. Respiratory depression from opioids, or reduced conscious level from sedatives, leading to hypoxia and aspiration, rather than the toxin itself being the immediate killer.

Best first test. Again there is no universal test. Check blood glucose, paracetamol and salicylate levels when the agent is unknown or overdose is possible, arterial blood gas, ECG for QRS or corrected QT changes, and serum osmolality and anion gap when a toxic alcohol is suspected. Specific levels, such as paracetamol, iron or lithium, are added from the history.

Best first treatment. Stabilise airway, breathing and circulation; give oxygen; pass a nasogastric tube only if the airway is protected; and seek toxicology or poison-centre advice before decontamination. Activated charcoal is used only in selected cases within a short time of a significant ingestion and only in a cooperative patient with a protected airway. Antidotes are given by toxidrome: naloxone for opioid, N-acetylcysteine for paracetamol, atropine and oximes for organophosphates, and flumazenil only in carefully selected benzodiazepine cases. Gastric lavage is no longer routine.

Commonest wrong answer. Giving a routine "coma cocktail", inducing vomiting, or starting charcoal hours after a sustained-release overdose without poison-centre advice.

Full topic page. emergency-medicine/poisoning-and-overdose.

Presenting picture. Sudden onset after a likely trigger of airway symptoms (hoarseness, stridor, tongue or throat swelling), breathing symptoms (wheeze, dyspnoea), circulation symptoms (faintness, hypotension) or skin and mucosal changes (urticaria, angioedema). Gastrointestinal symptoms may dominate. A patient with known allergy and sudden collapse needs no other diagnosis.

Single most likely diagnosis. Anaphylaxis. The commonest wrong pattern is to wait for skin signs before treating.

Best first test. None. The diagnosis is clinical and the treatment comes before the test. Mast cell tryptase taken in the first hours after onset, and a convalescent level, helps confirm the episode afterwards.

Best first treatment. Intramuscular adrenaline into the anterolateral thigh immediately, at a dose of 0.01 mL per kilogram of body weight up to a total of 0.5 mg per dose of 1 mg per mL concentration, repeated in short intervals of 5 to 10 minutes until the patient is stabilised ^[9]. Lay the patient flat, raise the legs, give high-flow oxygen and intravenous crystalloid for hypotension, and add nebulised adrenaline and bronchodilators for bronchospasm. Antihistamines and corticosteroids such as hydrocortisone 200 mg intravenously in adults are only adjuncts and must not delay adrenaline ^[8]. Refer for anaphylaxis follow-up after recovery ^[8].

Commonest wrong answer. Using the intravenous or subcutaneous route or an incorrect dose first, or giving antihistamines and steroids while withholding adrenaline.

Full topic page. emergency-medicine/anaphylaxis.

Presenting picture. An unresponsive patient with absent or abnormal breathing. The rhythm is either shockable (ventricular fibrillation or pulseless ventricular tachycardia) or non-shockable (pulseless electrical activity or asystole).

Single most likely cause in an adult. A primary cardiac arrhythmia, most often triggered by acute coronary ischaemia, followed by hypoxia, hypovolaemia and electrolyte or toxic causes. In trauma, think hypoxia then hypovolaemia, then tamponade or tension pneumothorax before primary arrhythmia.

Best first test. Rhythm check on the defibrillator or monitor after minimal interruption to chest compressions. Look for reversible causes during compressions using bedside ultrasound and the history: hypoxia, hypovolaemia, hyper or hypokalaemia, hypothermia, tension pneumothorax, tamponade, toxins, thrombosis.

Best first treatment. High-quality chest compressions at 100 to 120 per minute, depth 4 to 6 cm in adults, with full recoil and minimal pauses, plus early defibrillation for a shockable rhythm at the energy recommended by the device, starting with one shock per cycle and resuming compressions immediately. Ventilate with a bag-valve device and high-flow oxygen and secure the airway when feasible without interrupting compressions. Adrenaline 1 mg intravenously or intraosseously as a bolus, diluted to 10 mL of 1:10,000 concentration, repeated every 3 to 5 minutes throughout resuscitation ^[11]. In shockable rhythms the first doses are given after a few defibrillation attempts, while in non-shockable rhythms adrenaline is given as soon as vascular access is secured ^[11]. Consider amiodarone after failed shocks, and treat reversible causes throughout.

Commonest wrong answer. Stopping compressions to check a pulse too often, delivering stacked shocks without compressions, or forgetting that a deteriorating patient in cardiac arrest may be bleeding out.

Full topic page. emergency-medicine/cardiac-arrest-algorithms.

• The first minutes decide survival in all twelve presentations, and in every one the sequence is airway first, then breathing, then circulation.
• Acute abdomen is a clinical diagnosis with delayed imaging; never send a deteriorating, rigid patient for a scan before source control.
• In major trauma, crystalloids are not for the bleeding patient; use blood components, and remember the 1:1 plasma to red cell ratio.
• Tranexamic acid for head injury is given within 2 hours and before imaging.
• A head CT is needed within 1 hour for high-risk findings, and within 8 hours for loss of consciousness or amnesia plus further factors.
• Cool a fresh burn with running water for at least 20 minutes, but protect the patient from hypothermia.
• Strangulation converts any hernia into a same-day emergency.
• Ruptured abdominal aortic aneurysm is diagnosed at the bedside by ultrasound; a diameter of 5.5 cm or more is the referral threshold. ^[3]
• A cold pale leg with absent pulses is acute ischaemia until proved otherwise, and anticoagulation precedes imaging.
• Breast lumps in women aged 30 or over need a suspected cancer pathway referral, and a hard thyroid lump should not be watched.
• Anaphylaxis is treated with intramuscular adrenaline first, at 0.01 mL per kilogram up to 0.5 mg per dose, repeated every 5 to 10 minutes, with antihistamines and steroids only as adjuncts. ^[9]
• Cardiac arrest survival depends on early high-quality compressions, early defibrillation of shockable rhythms, adrenaline 1 mg every 3 to 5 minutes, and relentless treatment of reversible causes. ^[11]

• surgery/acute-abdomen; emergency-medicine/abdominal-examination-and-presentation
• emergency-medicine/trauma-primary-survey; emergency-medicine/head-injury
• emergency-medicine/burns; emergency-medicine/shock
• surgery/postoperative-complications; surgery/hernias
• vascular/abdominal-aortic-aneurysm; vascular/acute-limb-ischaemia
• breast/breast-examination-and-presentation; endocrine/thyroid-protocols
• emergency-medicine/poisoning-and-overdose; emergency-medicine/anaphylaxis
• emergency-medicine/cardiac-arrest-algorithms

Where this page quotes a number, the guideline edition is named in the text and in the reference list above. NICE documents are referenced by number and publication date. The resuscitation advice follows the 2026 Singapore Advanced Cardiac Life Support guidelines, which are based on American Heart Association guidance, because an open-access current document was available. Guidelines differ between regions and local protocols should be followed.