Abdominal and pelvic trauma

• Abdominal and pelvic trauma is managed in order of lethality: airway and breathing first, then circulation, then the specific injury.
• Blunt trauma is far more common than penetrating trauma; most blunt solid-organ injuries are now managed without surgery when the patient is haemodynamically stable.
• A haemodynamically unstable patient with free fluid on FAST goes to theatre without waiting for a scan; a stable patient gets a CT with intravenous contrast.
• Seat-belt bruising is not cosmetic: it is linked to roughly a 12% chance of bowel injury, most often small bowel. ^[5]
• Pelvic bleeding is mainly venous; most deaths are from uncontrolled haemorrhage and from coagulopathy, so a pelvic binder, blood products and rapid control matter more than the fracture pattern.
• Raised pressure in the abdomen can become its own emergency: sustained intra-abdominal pressure at or above 12 mmHg is intra-abdominal hypertension, and above 20 mmHg with organ failure is abdominal compartment syndrome, treated by decompressive laparotomy.

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

1. Run the primary survey for abdominal and pelvic trauma and decide who goes straight to the operating theatre.
2. Recognise the seat-belt sign and explain why it predicts hollow-viscus injury.
3. Compare solid-organ injuries (spleen, liver, kidney) and hollow-viscus injuries (duodenum, pancreas, diaphragm, bowel) and state the first-line management for each.
4. Explain when to use FAST, CT with contrast and diagnostic peritoneal lavage, and interpret a DPL.
5. Manage a pelvic-ring fracture: stability, binder, external fixation, angioembolisation and preperitoneal packing, plus bladder and urethral injuries and blood at the meatus.
6. Define and treat intra-abdominal hypertension and abdominal compartment syndrome.

This page covers trauma to the abdomen and pelvis in adults, with paediatric differences noted where they change management. It assumes a trauma team, a massive transfusion protocol and access to CT, but it also states what to do when these are unavailable. It treats the abdomen as a container of bleeding solid organs, leaking hollow tubes, and a retroperitoneal space that can hide several litres of blood. The high-level plan is always the same: find and stop bleeding, control contamination, restore physiology, then repair anatomy.

Abdominal and pelvic trauma is usually blunt (road traffic collisions, falls, assaults) and sometimes penetrating (stab and gunshot wounds). Prehospital and hospital care follow the Advanced Trauma Life Support (ATLS) primary survey, in which airway and breathing are secured before circulation is addressed. Abdominal bleeding is a leading cause of preventable trauma death. ^[4]

Abdominal trauma is any injury to the abdominal wall, peritoneal cavity, retroperitoneum, solid or hollow organs, great vessels or pelvic structures caused by blunt or penetrating force. Blunt injury transfers energy without a break in the skin; penetrating injury breaches the skin and fascia. Pelvic trauma covers injuries to the pelvic ring, its viscera (bladder, urethra, rectum) and the major vessels that run through it. ^[4]

Solid and hollow organs are graded with the American Association for the Surgery of Trauma organ injury scale (AAST-OIS), from grade I (minor contusion or superficial laceration) to grade V (shattered organ or hilar devascularisation). The World Society of Emergency Surgery (WSES) combines the AAST grade with haemodynamic status into three classes: minor, moderate and severe. Haemodynamic stability is defined here as systolic blood pressure above 90 mmHg after minimal fluids with heart rate under 100 beats per minute; instability is systolic pressure under 90 mmHg, or over 90 mmHg but needing bolus fluids, transfusion or vasopressors, with a base deficit worse than -5 mmol per litre, a shock index above 1, or a transfusion requirement of at least 4 to 6 units of packed red cells in the first 24 hours. A transient responder stabilises briefly and then deteriorates, and is managed as unstable. ^[1][6]

Haemodynamic grading drives every decision below: unstable patients go to theatre, stable patients get cross-sectional imaging, and a large group in between is observed closely.

Abdominal and pelvic injuries are part of the trauma burden that falls hardest on young adults. In Western cohorts blunt mechanisms dominate road traffic collisions, while in many low- and middle-income settings penetrating injury from stabs, gunshots and conflicts is at least as common. Overall, in large trauma series 10 to 15% of patients with pelvic fractures arrive in shock, and one third of those die, with quoted mortality around 32% in the most recent reports. Urogenital injuries occur in 10 to 20% of abdominal trauma, and the kidney is involved in 65 to 90% of those. ^[4] Traumatic diaphragmatic rupture itself is uncommon, at about 0.5% of all trauma patients. ^[10] Hollow viscus and mesenteric injuries are rare in blunt trauma, at about 1%, but occur in about 17% of penetrating trauma. ^[1][5][6]

A male preponderance is reported for urogenital trauma, with males affected about three times as often as females. Children are injured differently: their kidneys and bladders are more exposed because of thinner muscles, less perirenal fat and unossified ribs, so urogenital injury is relatively more common in children even though it is still uncommon overall. ^[4]

Mechanisms group into three categories. Rapid deceleration (head-on collision, fall from height) produces shear at fixed points: the duodenum at the ligament of Treitz, the duodeno-pancreatic complex, the renal pedicle, and the diaphragm. Compression or crush (steering wheel, seat belt, direct blow) raises intra-abdominal pressure suddenly and ruptures hollow organs or bursts the spleen and liver against the spine. Penetrating mechanisms (stab, gunshot) injure whatever lies in the tract, including retroperitoneal structures.

Modifiable risks are alcohol or drug intoxication, not using seat belts or crash helmets, and unsafe work at height. Non-modifiable risks include age and frailty, osteoporosis, chronic lung disease and anticoagulation. The single most important reversible error in prehospital care is an unfastened or misplaced seat belt: a belt worn high on the abdomen transfers load to the bowel and spine rather than the pelvis.

Spleen. The spleen is the most commonly injured solid organ in blunt trauma. Bleeding is venous and brisk; a subcapsular haematoma can rupture hours or days later (delayed rupture), and a pseudoaneurysm can rupture after the patient has stabilised. The spleen is also immunologically important, so salvage is preferred when physiology allows.

Liver. The liver is large, vascular and sits under the rib cage. Hepatic bleeding can be arterial from the hepatic artery or portal venous, and severe injuries can bleed from the retrohepatic vena cava or hepatic veins, which are the most dangerous.

Kidney. The kidney is mobile on the renal pedicle and prone to shear in deceleration. Blood may track into the retroperitoneum and not appear as free intraperitoneal fluid, so a negative FAST does not exclude renal injury. ^[3]

Duodenum. The duodenum is fixed, partly retroperitoneal, and receives gastric acid and enzymes. Perforation leaks enzymatically inactive but contaminated contents; peritonitis therefore develops slowly, sometimes over hours.

Pancreas. The pancreas is retroperitoneal and bleeds and enzymatically leaks when its duct is disrupted. Serum amylase and lipase rise, but they can be normal in up to 40% of patients on admission and only become useful after 3 to 6 hours. ^[6]

Diaphragm. The pressure in the abdomen is higher than in the chest and can rise tenfold in trauma. A diaphragmatic tear does not heal because the diaphragm moves continuously, so herniation of abdominal organs can occur early or years later. Most tears are on the left, because the liver protects the right side. ^[10]

Bowel and mesentery. Hollow-viscus perforation after blunt trauma is uncommon (about 1%) but devastating if missed. Luminal contents are near neutral pH early on, so peritoneal signs develop slowly. The mesentery can be torn with partial devascularisation, leading to delayed necrosis days later.

The pelvis is a rigid ring containing the bladder, rectum, vessels and nerves. Bleeding is venous in about 80% of pelvic fractures (presacral plexus, prevesical veins) and arterial in about 20% (branches of the internal iliac, particularly the obturator, pudendal, superior gluteal and lateral sacral arteries). ^[1] A fracture opens the pelvic ring, increasing its volume and reducing the tamponade effect; an open-book fracture can hold several litres of blood in the retroperitoneal tissues. High-energy pelvic fractures are accompanied by associated injuries in up to 80% of cases, including bladder or urethral injury in 1.6 to 25% and anorectal injury in 18 to 64%. CT signs of an arterial source include active contrast extravasation ("blush") and a pelvic haematoma of 500 cubic centimetres or more even without a visible blush.

Bleeding behind the peritoneum (renal, major vascular, pelvic) is concealed and may not appear as free fluid on FAST or CT. It is diagnosed by contrast CT and by clinical signs of haemorrhage with no intraperitoneal source. Management follows the source: pelvic haematomas are handled with stabilisation and angioembolisation or packing rather than surgical exploration, while central retroperitoneal haematomas from penetrating trauma that are expanding or pulsatile are explored. Any haematoma that is unstable or expanding overrides the category.

Intra-abdominal hypertension (IAH) is a sustained or repeated intra-abdominal pressure (IAP) of 12 mmHg or higher, graded I (12 to 15), II (16 to 20), III (21 to 25) and IV (over 25 mmHg). ^[7] Normal IAP in critically ill adults is 5 to 7 mmHg. Abdominal compartment syndrome (ACS) is a sustained IAP above 20 mmHg associated with new organ dysfunction or failure. The pressure is transmitted to the thorax, reducing venous return and cardiac output and raising intracranial and airway pressures, and it reduces renal perfusion and urine output. ACS is common after damage-control surgery, massive transfusion, over-resuscitation and severe abdominal trauma, and is an under-recognised cause of deterioration in the intensive care unit. In children ACS is defined at a lower threshold: sustained IAP above 10 mmHg with organ dysfunction. IAP is measured through the bladder with no more than 25 mL of sterile saline instilled, at end-expiration, in the supine patient with no abdominal muscle contraction; in children the instillation volume is 1 mL per kg, minimum 3 mL, maximum 25 mL. ^{[4][6] [10]}

Ask about the mechanism, speed, seat-belt use, airbag deployment, and any direct blow to the abdomen. Symptoms may be delayed: abdominal pain, distension, haematuria, or referred shoulder-tip pain from diaphragmatic irritation. Falls onto an outstretched hand suggest splenic or hepatic injury in children.

Inspect for seat-belt bruising, abrasions, distension and penetrating wounds; palpate for tenderness, guarding and rigidity. Pelvic instability and perineal haematoma are signs of pelvic ring disruption. Digital rectal examination looks for blood and a high-riding or non-palpable prostate; perineal and rectal examination are mandatory when rectal injury is suspected. Blood at the urethral meatus (or a high-riding prostate) suggests urethral injury and should stop any attempt at urethral catheterisation until imaging is done.

• Spleen: left upper quadrant tenderness, Kehr sign (shoulder-tip pain), friction rub.
• Liver: right upper quadrant tenderness, rib fractures, hypoventilation.
• Kidney: flank pain, haematuria (macro- or micro-), fractures of the lower ribs.
• Duodenum and pancreas: epigastric or right upper quadrant pain after a blow, often with a delayed presentation of 6 to 24 hours, and sometimes up to 5 days.
• Diaphragm: dyspnoea, shoulder pain, absent breath sounds, bowel sounds in the chest.
• Bowel: initially little to find; worsening pain, distension, peritonitis later.

Many patients with chest, abdominal or pelvic trauma also have medical causes of pain and breathlessness, and some injuries mimic each other. The table separating the common possibilities by the feature that distinguishes them.

• E-FAST (extended FAST). A rapid bedside ultrasound: pericardium, right upper quadrant (Morrison pouch), left upper quadrant (splenorenal pouch), pelvis, and pleural spaces for hemothorax and pneumothorax. It gives a simple yes or no answer and is used in haemodynamically unstable patients. ^[8] It detects free fluid with sensitivity around 85% once 150 to 200 mL has accumulated, and traditional FAST detects pericardial and intraperitoneal fluid with sensitivity 85 to 96% and specificity above 98%. It takes under 5 minutes, usually under 2 minutes in experienced hands. It is poor at detecting retroperitoneal and solid-organ injuries and must not delay laparotomy in a shocked patient with obvious bleeding. ^[3]
• Pelvic and chest X-ray. In the unstable patient, to detect pelvic-ring disruption and haemothorax or pneumothorax. Pelvic X-ray has low sensitivity for fractures; it does not predict bleeding or need for angioembolisation. ^[1]
• Clinical examination and laboratory tests. Base deficit and lactate (sensitive early markers of haemorrhage), full blood count, clotting and platelets, crossmatch, renal function and urinalysis (haematuria).

• CT abdomen and pelvis with intravenous contrast is the gold standard in haemodynamically stable or stabilised patients, with sensitivity and specificity approaching 96 to 100% for solid-organ injury. ^[2] Delayed (urographic) phases detect urinary extravasation and ureteral or bladder injury. A multidetector CT with arterial, portal and delayed phases is preferred when pelvic arterial bleeding is suspected. ^[3]
• CT with 3-D reconstruction helps plan pelvic fixation.
• Retrograde urethrogram before catheterisation in any patient with perineal or scrotal haematoma, blood at the meatus, a non-palpable or high-riding prostate, or an unstable pelvic fracture.
• Retrograde cystography (conventional or CT) is the test of choice for suspected bladder rupture; intravenous contrast CT with a delayed phase is less sensitive and specific for bladder injury.
• MRCP is second-line for suspected pancreatic duct or biliary injury.
• ERCP can both diagnose and treat pancreatic duct or extrahepatic biliary injury in stable patients.
• IAP monitoring when intra-abdominal hypertension is suspected (see below).

In shock, or where CT is not available, DPL remains useful. It is positive in adults if any of the following is found: more than 10 mL of gross blood on aspiration, white cell count above 500 per cubic millimetre, red cell count above 100,000 per cubic millimetre, or enteric or vegetable matter. ^[9] A minimum of 30% of the infused volume (usually 300 to 350 mL in an adult; 10 to 15 mL per kg in children, with 20 to 30% return) must come back for a valid sample. In children, DPL uses 10 to 15 mL per kg of warm crystalloid. Complication rates in large series are 0.8 to 1.7%. DPL is highly sensitive for mesenteric and hollow-viscus injury but poor for retroperitoneal and diaphragmatic injuries. FAST and DPL do not evaluate retroperitoneal bleeding well. ^[6]

The triage is by haemodynamic state, not by scan, and the thresholds above apply. Severity is graded with AAST-OIS and WSES classes. For solid organs, WSES classes are essentially: minor (haemodynamically stable, AAST I to II), moderate (stable, AAST III), severe (stable, AAST IV to V), and unstable (any grade with haemodynamic instability). For hollow-viscus and biliary injury the WSES classes are described below and in the organ paragraphs.

Non-operative management (NOM) is the standard for haemodynamically stable solid-organ injury without another reason to operate. NOM requires a CT with intravenous contrast, an intensive-care setting with monitoring, serial haemoglobin, and an operating theatre and interventional radiology available around the clock, and it is contraindicated in unresponsive instability, peritonitis, bowel evisceration or impalement. NOM succeeds in about 90% of blunt splenic trauma in experienced centres. ^[3] Failure is more likely with age over 55 years, high injury severity score, and moderate to severe splenic injury.

Angioembolisation (AG/AE) is a first-line extension of NOM when there is active contrast extravasation ("blush") on CT in a stable patient. ^[2][3] It can be repeated if needed.

Follow ATLS. Open or decompress the airway, give oxygen, control external bleeding, obtain vascular access and give blood according to a massive transfusion protocol (transfusion is tailored to coagulation status where testing is available). Examine the abdomen only enough to decide the next step. Give tranexamic acid only if within local protocol and indicated.

Decision to operate is clinical, not radiological:

• Haemodynamic instability or non-response to resuscitation with a positive FAST means emergency laparotomy.
• Peritonitis, evisceration, impalement, frank per rectal blood with intraperitoneal injury, or free intraperitoneal air means laparotomy.
• In penetrating trauma, "hard signs" also include enteric contents in the wound, haematemesis, frank blood on nasogastric aspiration, and organ evisceration.
• Pelvic-ring disruption with haemodynamic instability means pelvic binder plus resuscitation plus haemorrhage control (below), not immediate laparotomy, unless there is a clear intra-abdominal source.

Damage-control resuscitation (permissive hypotension, limited crystalloid, high plasma-to-red-cell ratio) and damage-control surgery (rapid control of bleeding and contamination, temporary abdominal closure, definitive repair later) are the standards for the physiologically exhausted patient. Decompressive laparotomy is indicated for abdominal compartment syndrome.

• Pelvic binder applied at the level of the greater trochanters and pubic symphysis, legs adducted, as early as possible, ideally prehospital. Binders are superior to sheet wrapping. They should be removed as soon as physiologically justifiable and replaced by external or definitive fixation; continuous pressure above 9.3 kPa for more than 2 to 3 hours risks skin necrosis. Avoid prolonged use (no more than 24 to 48 hours) and position carefully in pregnancy and in older adults. ^[1]
• External fixation or a C-clamp for mechanically unstable pelvic-ring injuries in stable patients (WSES grade II and III).
• Preperitoneal (prevesical) pelvic packing in unstable patients, especially where angioembolisation is unavailable.
• Angioembolisation for haemodynamically stable patients with a CT blush or a pelvic haematoma of at least 500 cubic centimetres, and in any stable patient with WSES grade III splenic injury regardless of blush.
• REBOA (resuscitative endovascular balloon occlusion of the aorta), usually zone III, as a bridge to definitive control in unstable patients with suspected pelvic bleeding, with Zone I when the source is unknown; partial or intermittent occlusion limits ischaemia.
• Laparoscopy is a safe diagnostic and therapeutic tool in stable patients and is particularly useful for detecting diaphragmatic rupture.

Massive transfusion protocols guide blood products to coagulation status. Antibiotic prophylaxis and any specific drug therapy (for example analgesia, antiemetics) follow local protocols. No patient-specific doses are given here; use the local formulary and weigh the risks in each case. Early thromboprophylaxis is recommended once bleeding is controlled: mechanical prophylaxis first, then low-molecular-weight heparin as soon as safely possible, including in non-operatively managed stable solid-organ injury. After splenectomy, immunisation against encapsulated organisms (pneumococcus, Haemophilus influenzae and meningococcus) should be given, usually no sooner than 14 days afterwards, or before discharge if the patient leaves earlier.

Spleen. Non-operative for all haemodynamically stable patients irrespective of grade, with a CT with contrast and monitoring. Angioembolisation is considered first-line in grade III (AAST) or higher injuries and in any stable patient with a blush. ^[3] Splenectomy is reserved for haemodynamic instability, failed embolisation, or peritonitis, bowel evisceration or impalement. Salvaging part of the spleen in theatre is debated. Laparoscopic splenectomy in the acute bleeding patient is not recommended.

Liver. Non-operative for stable patients of all grades (WSES I to III). Arterial blush on CT may be angioembolised first-line. ^[2] Unstable non-responders need surgery: control haemorrhage and bile leak, damage-control packing, early recourse to massive transfusion; major resection is avoided at the first operation and attempted later by experienced surgeons if large areas of devitalised tissue exist. Retrohepatic or suprahepatic venous injuries are managed first by packing. Two indications prompt postoperative angioembolisation: a blush on a completion CT, and suspected arterial bleeding that persisted despite laparotomy. After blunt hepatic trauma, complications (bile leak, abscess, pseudoaneurysm, re-bleeding in 1.7 to 5.9%) occur in 12 to 14%. ^[2]

Kidney. Non-operative for all haemodynamically stable or stabilised injuries (grades I to V). Angioembolisation is indicated for contrast extravasation, pseudoaneurysm or arteriovenous fistula: superselective where possible, and blind embolisation is not indicated. Stable patients with main renal artery dissection or occlusion within a limited warm ischaemia time may be considered for endovascular repair in specialist centres. Surgery is reserved for instability, non-response, severe vascular injury with non-self-limiting bleeding, or associated injuries requiring laparotomy. Isolated urinary extravasation is not in itself an indication to operate. ^[4]

Duodenum. NOM is acceptable in haemodynamically stable patients with wall haematoma only (WSES class I to II, AAST grade I to II). Unstable patients and those with peritonitis, evisceration or impalement need immediate surgery. Primary repair is preferred whenever technically possible; destructive injuries (more than 50% of the circumference, or devascularised bowel) and injuries to the second part involving the ampulla (grade III to V) may need ancillary procedures or staged pancreaticoduodenectomy (Whipple). Haematomas that have not resolved after 14 days should be operated on.

Pancreas. NOM is the treatment of choice for stable minor injuries (WSES class I, AAST grade I and some grade II) and distal class II injuries need surgery: distal pancreatectomy with or without splenectomy. Severe proximal injuries (class III) are controversial; NOM augmented with endoscopic or percutaneous stenting may be used in selected stable patients only in centres with round-the-clock endoscopy, interventional radiology, surgery and blood products. Repeated amylase and lipase measurement from 3 hours after injury supports diagnosis, with a rising level prompt for further imaging.

Extrahepatic biliary tree. Gallbladder contusion or simple injuries are treated non-operatively; gallbladder laceration, perforation or avulsion is treated with cholecystectomy. More severe ductal injuries (class II to III) require reconstruction (hepaticojejunostomy or choledochojejunostomy) if there is no vascular injury.

Diaphragm. This is always repaired once found, because tears do not heal. In acute polytrauma the approach is dictated by the life-threatening injury (laparotomy in 94% of series). A simple tear up to 5 to 6 cm is closed with monofilament sutures; larger defects need figure-of-eight or mattress sutures. Delayed (latent) tears are repaired electively via a transthoracic or minimally invasive approach. About 10% of blunt and 15 to 30% of penetrating chest injuries need an operation at all. ^[10]

Bowel and mesentery. Haemodynamically decompensated patients with a positive FAST go straight to laparotomy. Stable patients with seat-belt sign or high-risk mechanism need CT with contrast and a high index of suspicion. Highly specific CT signs (free air, extraluminal contrast, bowel-wall defect, metallic fragments in penetration) mandate exploration. Free fluid without solid-organ injury, mesenteric stranding and bowel-wall thickening are sensitive but not specific. In stable patients with equivocal findings, admit and re-image: repeat CT at 6 hours if the initial scan is equivocal, or sooner if the clinical picture evolves. NOM is possible only in selected specialist centres with structured observation and serial clinical examination, and only for penetrating trauma without hard signs. During surgery, primary repair of small-bowel injury is preferred; a primary anastomosis of colonic injury is safe in patients with good physiology, while high-risk patients get a stoma. Damage-control surgery (rapid control of bleeding and contamination, temporary closure, restoration later) avoids a long definitive operation in the exhausted patient. ^[5]

Pelvic-ring fractures are caused by high-energy falls, sports injuries and road traffic collisions. The WSES classification incorporates the Young-Burgess pattern (anteroposterior compression, lateral compression, vertical shear, combined mechanism) with haemodynamic state: minor (grade I: stable ring, stable patient), moderate (grades II and III: unstable ring but stable patient) and severe (grade IV: any unstable patient). About 60 to 90% of patients with bladder injury have a pelvic fracture, and 6 to 8% of patients with a pelvic fracture have a bladder injury. ^[4]

Ten to fifteen per cent of patients with pelvic fractures arrive in shock. Bleeding is venous in roughly 80% and arterial in 20%. High-grade pelvic fractures are associated with thoraco-abdominal injuries in up to 80% of cases. Local injuries (bladder, urethra in 1.6 to 25%, rectum in 18 to 64%, vagina, nerves) should be suspected with perineal haematoma or major soft-tissue disruption. ^[1]

Diagnosis and control follow a set sequence:

• In the unstable patient, pelvic and chest X-rays with E-FAST are done in the emergency department; CT is reserved for stable or stabilised patients, whose intravenous-contrast CT is the gold standard.
• A binder is applied early; commercial binders control bleeding better than sheets.
• If shock persists, add preperitoneal pelvic packing (especially where there is no angiography service) and mechanical fixation (external fixation or C-clamp) for unstable rings.
• Angiography with embolisation is indicated for stable patients with a CT blush, or a pelvic haematoma of at least 500 cubic centimetres, and it is used in unstable patients after other measures if bleeding continues. Arterial injuries are branches of the internal iliac artery.
• REBOA in zone III is a bridge for unstable patients with suspected pelvic arterial bleeding, and zone I when the source is unknown.
• Definitive internal fixation is planned once the patient is stable and after any other surgery.

Perineal and rectal examination are mandatory when rectal injury is suspected, with proctoscopy if positive. Retrograde urethrogram or urethrocystogram with contrast CT is recommended with local perineal haematoma and pelvic disruption on X-ray. Performing the retrograde study before CT can increase the rate of indeterminate or false-negative CT scans, so in stable patients a late-contrast CT urologic study is preferred.

Bladder and urethral injury. Blood at the urethral meatus, perineal or scrotal haematoma, a high-riding or non-palpable prostate, or an unstable pelvic fracture mandates retrograde urethrography before any catheter is passed. Urethral injury complicates 1.5 to 5% of anterior pelvic fractures, and the risk rises by 10% for every 1 mm of pubic symphysis diastasis. ^[4] Posterior injuries occur proximal to the perineal membrane and are more common in pelvic fractures. Intraperitoneal bladder rupture (15 to 25% of bladder injuries) is repaired operatively; uncomplicated extraperitoneal rupture can be drained non-operatively with a catheter except when the bladder neck, rectum or vagina are involved. Partial urethral injuries and posterior urethral injuries are initially managed with drainage and, where appropriate, endoscopic realignment, with definitive urethroplasty delayed until the pelvic ring has healed. Haemodynamically unstable patients with urethral injury are drained immediately and treated later.

Measure IAP whenever a risk factor is present in a critically ill or injured patient. Medical management comes first: analgesia, brief neuromuscular blockade, nasogastric or rectal decompression when the bowel or stomach is dilated, avoiding a positive fluid balance after the initial resuscitation, and body positioning. Percutaneous drainage can be used where there is obvious intraperitoneal fluid. If overt ACS is present, decompressive laparotomy is recommended. Trauma patients who are physiologically exhausted should be managed with a prophylactic open abdomen. Temporary closure uses negative-pressure wound therapy with a documented effort to achieve fascial closure during the same hospital stay.

Non-operative management requires serial clinical examination and haemoglobin checks (for penetrating trauma often for 48 hours). After blunt solid-organ injury, recovery takes days to weeks. Activity restriction after splenic injury is advised for a limited period after minor injury and longer after moderate or severe injury. CT is not repeated routinely during admission unless clinical findings change. Discharge planning for splenectomised patients must include a vaccination programme. ^[3]

• Haemorrhage: primary or delayed, including delayed splenic rupture and pseudoaneurysm rupture.
• Missed hollow-viscus injury, especially small-bowel perforation after blunt trauma, presenting with sepsis days later.
• Intra-abdominal and wound infection, abscess and anastomotic leak after bowel repair.
• Biliary complications after hepatic trauma (bile leak, biloma, haemobilia).
• Pancreatic fistula and pseudocyst after ductal injury.
• Abdominal compartment syndrome after damage-control surgery and over-resuscitation.
• Enterocutaneous fistula and fascial dehiscence with an open abdomen.
• Urethral stricture, incontinence and erectile dysfunction after posterior urethral injury.

Outcome after major blunt or penetrating abdominal trauma is driven by haemorrhage control and by associated injuries, particularly traumatic brain injury and haemorrhagic shock. Most minor solid-organ injuries heal without intervention. Delayed diagnosis of diaphragmatic, pancreatic or hollow-viscus injury increases morbidity and mortality. Blunt injuries carry higher mortality from associated head injury; penetrating injuries from multiple visceral injuries and bleeding.

Prevention is the management that matters most: seat belts and crash helmets, speed enforcement, falls prevention, and violence reduction. No screening programme exists for abdominal injury; trauma activation is based on mechanism and physiology. Early pelvic stabilisation and bundle care reduce mortality from pelvic fracture.

Children. Solid-organ injuries in children are treated non-operatively far more often than in adults. Paediatric splenic trauma should be managed in a dedicated paediatric trauma centre if possible; non-operative management in children has an even lower threshold for attempts, and angioembolisation is used less. Bladder and urethral injury in children is more often associated with pelvic fracture than in adults, but children have proportionally more isolated injuries because of their anatomy. Diaphragmatic and pancreatic injuries in children most often follow bicycle handlebar and motor vehicle accidents.

Pregnancy. The uterus displaces the bowel upward, so penetrating injuries may be less damaging to viscera but more threatening to the fetus. Diagnostic thresholds for imaging change; ultrasound is preferred for initial assessment, and for urethral injury endoscopic routes may differ. Pelvic binders should be placed carefully.

Older adults. Frailty and coagulopathy raise risk; lateral compression pelvic fractures predominate and may be treated with angioembolisation rather than mechanical stabilisation alone. CT and cross-matching thresholds lower.

Immunocompromised and asplenic patients. After splenectomy or splenic angioembolisation, patients need vaccination and must seek early treatment for fever.

Where CT, angioembolisation and interventional radiology are unavailable, the principles remain the same, executed with simpler tools. DPL is specifically useful in low-resource settings, and ultrasound with serial examination and blood tests can guide non-operative management of stable solid-organ injuries. Pelvic haemorrhage can be controlled with a "home-made" pelvic sheet binder, external fixation and preperitoneal pelvic packing. The damage-control laparotomy with temporary abdominal closure is the universal platform. Early transfer to a centre with blood products and surgery is the single most useful intervention. Even without CT, a shocked patient with a positive FAST needs an operating theatre, and delay reduces survival.

• Manage by physiology: unstable with positive FAST goes to theatre; stable patients get CT with intravenous contrast.
• Blunt solid-organ injuries (spleen 96 to 100% CT sensitivity, liver, kidney) are non-operatively managed in stable patients; instability, failed embolisation, peritonitis or evisceration means surgery. ^[2]
• A seat-belt sign carries roughly a 12% risk of bowel injury (small bowel 58%, large bowel 39%, spleen 39%): CT plus 24-hour observation if the scan is negative. ^[5]
• CT detects haemoperitoneum above 100 mL; FAST needs 150 to 200 mL; DPL positive thresholds are 10 mL gross blood, white cells above 500 per mm3, or red cells above 100,000 per mm3. ^[9]
• Pelvic bleeding is 80% venous and 20% arterial; a pelvic haematoma of 500 cubic centimetres or a CT blush means angioembolisation; a binder goes on early.
• Bladder rupture is intraperitoneal in 15 to 25% (operative) and extraperitoneal in 60 to 90% (usually non-operative with drainage). Urethral injury with blood at the meatus stops catheterisation until a retrograde urethrogram. ^[4]
• Abdominal compartment syndrome is sustained IAP above 20 mmHg with organ failure; measure via the bladder and treat with decompressive laparotomy.
• Non-operative management needs discipline: stable patient, CT with contrast, ICU monitoring, available theatre and blood products.
• Diaphragmatic tears do not heal and must be repaired whenever found.
• In low-resource settings, DPL, ultrasound, serial examination and damage-control surgery carry the same principles through.

Related reading (plain text, no links): "Thoracic trauma", "Initial trauma assessment (primary survey)", "Secondary survey and penetrating trauma", "Head and spinal injury in trauma", "Massive haemorrhage and damage-control resuscitation", and the topics on "Sepsis" and "Haematuria". Verify existing slugs before any future linking.