Abdominal Trauma

Abdominal Trauma Dr. Qiu Xinguang Department of General Surgery, First Affiliated Hospital, Zhengzhou University (450052)

Mechanism of Injury    

Blunt injury Penetrating injury Blast injury Iatrogenic injury

Blunt injury   

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Commonest mode Frequently multi-system injury Abdominal injury accounts for 10% blunt trauma death Road traffic accident

Mechanism of blunt injury   

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Direct impact Deceleration and rotational forces Liver and spleen are the most commonly injured organs Bowel injury (acute increase in intraluminal pressure / shearing at mesentery)

Penetrating injury 

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High velocity Gunshot wounds Low velocity Stab wounds / low-velocity missiles

Mechanism of penetrating injury 

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Stab wounds Injury confined to the tract of wounding Gunshot wounds Depends on the energy transferred Penetration is accompanied by shock wave with cavitating effect (spiral path of motion)

Blast injury  

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Positive and negative pressure waves Cause associated pressure changes in bowel gas (blowout) Victim thrown by the force of pressure waves Shrapnel

Iatrogenic injury   

Uncommon Laparoscopy Endoscopy

Primary survey and resuscitation 

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Objectives of this phase: To identify and correct any immediate lifethreatening conditions To anticipate problems The activities are performed simultaneously with enough personnel A- Airway and cervical spine control B- Breathing C- Circulation with haemorrhage control D- Disability E- Exposure

Airway and C-spine control  

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C-spine injury should be assumed No attempt should be made to turn the patient’s head to one side unless C-spine injury has been ruled out Oxygen provided once airway cleared and secured Beware of aspiration

Breathing 

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Anticipate SIX immediately life-threatening thoracic conditions: 1. Airway obstruction 2. Tension pneumothorax 3. Open chest wound 4. Massive haemothorax 5. Flail chest 6. Cardiac tamponade Respiratory rate and effort are both sensitive markers of underlying lung pathology (both should be monitored)

Circulation 

Key objectives of circulatory care: Stop haemorrhage Assess hypovolaemia Vascular assess Appropriate fluid resuscitation

Stop haemorrhage      

Direct pressure (external haemorrhage) Long bone fractures be splinted Pelvic binding Pneumatic anti-shock garment (PASG) Pelvic fracture may need external fixation Try to avoid: Vessel clamping Tourniquets (distal ischaemia)

Assessment for hypovolaemia      

Skin (colour, clamminess and capillary refill) Heart rate and BP Pulse pressure Conscious level ECG monitoring Search for common sites of occult bleeding: Chest Abdomen / Retroperitoneum Pelvis Long bones Splints and dressings

Vascular assess  

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Large bore IV catheter 20ml blood taken for grouping and xmatch and for e- + full blood count Femoral line / venous cut down / intra-osseous access (if peripheral IV assess failed) Central venous line insertion is not essential for initial resuscitation

Fluid resuscitation 

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Initial fluid resuscitation: 2L warmed crystalloid Responder: Give maintenance fluids once initial deficit replaced Transient responder: Deteriorate due to continued haemorrhage, give blood and urgent surgical opinion Non-responder: Ongoing haemorrhage at a greater rate, need urgent surgical opinion

Resuscitation end-point 

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Administer sufficient fluids to maintain perfusion of essential organs SBP 80mmHg (previously normotensive) Equivalent to a palpable radial pulse Permissive hypotension to minimize Ongoing haemorrhage Disruption of established thrombus Dilution of clotting factors Monitored vitals: Resp rate, SaO2, HR, BP, Pulse pressure, Cardiac monitoring, Temp, Urine output, GCS

Urethral injury  

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Far more common in male patients 5-25% patients with pelvic fractures have an associated urethral injury Symptoms: Perineal pain Dysuria Failure to void Signs: Blood at urethral meatus Bruising around scrotum High-riding prostate

Urethral injury 

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Urinary catheterization is contraindicated: Conversion of partial to complete transection Stricture formation Introduce infection Diagnosis confirmed by retrograde urethrogram

Disability 

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Baseline neurological examination: AVPU response Glasgow comma scale (if time permits) Pupillary response Repeated assessment to look for signs of deterioration Common causes of deterioration: Hypoxia Hypovolaemia Hypoglycaemia Raised ICP

Exposure 

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Trauma victims must be kept warm and covered with blankets when not examined Log-roll Assess the spine from skull base to coccyx Examine the back for signs of injury Rectal examination

Secondary survey (abdominal examination) 

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Key objective: To decide if laparotomy is needed Detailed examination of the abdomen, pelvis and perineum Note for bruising and wounds Cover exposed bowel loops with warm NS soaked gauze Gastric tube to decompress distended stomach to facilitate abdominal examination and reduce risk of aspiration

Physical examination 

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Most alert patients will have abdominal tenderness Initial PE in blunt abdominal trauma is only 65% accurate Altered mental state (drugs, alcohol, HI, etc) Sensory abnormalities (spinal cord injury) Distracting injuries (extra-abdominal) Serial examinations are often more important

Physical findings 

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Distension Usually 20 to ileus or pneumoperitoneum or haemoperitoneum Bruising

Palpation     

Lower ribs fracture Abdominal tenderness, guarding or rebound Pelvic stability Lumbar spine for tenderness Rectal examination Anal tone Prostate position (?high riding) Blood over examination glove

Plain radiographs 

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CXR The most important plain film Obvious intra-thoracic and diaphragmatic injuries Pelvis (AP view) C-spine (Lat view) make sure C1-C7 are well shown AXR seldom helpful (not routine)

Laboratory studies 

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Laboratory tests play limited role in the diagnosis of IAI (normal test never R/O IAI) Baseline Hb level Acid-base status Amylase (not sensitive / specific) Urinalysis (gross haematuria is the most consistent sign of serious renal injury)

Diagnostic peritoneal lavage 

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Before the introduction of DPL ~20% patient with abdominal trauma died of unrecognized injury Sensitive 97-99% Fast (5-15 min) False +ve 1.4% Complication rate 1% No information on retroperitoneal organs Not sensitive to detect diaphragmatic or bladder injuries (these result in minimal bleeding)

Contraindication of PDL 

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Absolute Obvious need for laparotomy Evisceration Relative Pregnancy (>12 wks) Previous abdominal surgery

Criticism of PDL  

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Overly sensitive Non-bleeding solid organ injuries (which can be managed conservatively) Non-therapeutic laparotomies Best preserved for hypotensive, unstable, multi-injured patients

Techniques   

Closed percutaneous Semi-closed Open 1 Liter of warm normal saline is instilled in adults 15 ml/kg in children A minimum of 300 ml of lavage fluid must return to give a representative sample

Positive results of DPL 

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10ml gross blood or bowel contents with initial aspiration RBC count >100,000 cells/ml in blunt trauma RBC count >10,000 cells/ml in stab wounds RBC count >5000 cells/ml in penetrating chest trauma WBC count >500 cells/ml

Ultrasound 

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Kristensen et al first reported the use of USG in abdominal trauma in 1971 Non-invasive and inexpensive Portable (bed side) No radiation / contrast required Well tolerated (excellent for unstable patients) Quick (within 3 mins in experienced hands) Serial examination easy to perform Best screens for haemoperitoneum

FAST technique 

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Focused Abdomianl Sonography for Trauma (Rozycki et al) A standard approach which involves imaging a limited number of US windows to detect fluid: RUQ (Morison’s pouch) LUQ (to view the spleen) Pelvis (Douglas pouch) Pericardial window to assess for pericardial effusion (epigastric)

Reliability of FAST   

Sensitivity 93.4% Specificity 98.7% Accuracy 97.5% A collected review of ~5000 patients (with FAST performed by surgeons) Rozycki and Shackford J Trauma 1996; 28: 483-9

Results interpretation 

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Unstable patients with a +ve US requires laparotomy Stable patients can be followed by serial US or employ CT for further evaluation

Limitations        

Operator dependent Uncooperative / agitated patients Obesity Surgical emphysema Ileus Cannot assess retroperitoneal organs Like CT, US is insensitive for bowel injury Poor sensitivity for penetrating trauma

Abdominal computed tomography 

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Introduced in late 1970s for trauma management CT quantifies intraperitoneal blood and grades organ injury IV and oral contrast Accuracy is extremely readerdependent Modern spiral scan requires 3-5 mins Dome of diaphragm to pelvis

Precautions  

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Haemodynamically stable More time consuming than DPL / FAST 30-50 min Adequate monitoring Resuscitation facilities must be available in the CT room

Diagnostic laparoscopy  

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DL is a relatively new investigation Little evidence to support its role in blunt trauma Not sensitive in Dx hollow viscus and retroperitoneal injury Penetrating trauma (stab wounds) in stable patient 100% sensitivity for identification of peritoneal penetration Most effective for diagnosing ruptured diaphragm

Limitation of DL    

Time consuming Invasive General anaesthetic Difficult to exclude hollow viscus perforation

Management approach for blunt abdominal trauma 

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Unstable patient with abdominal sign Operation Unstable patient with uncertain abdominal injury DPL or FAST Stable patient with associated severe injuries DPL or FAST Stable patient with associated minor injuries and equivocal abdomen CT scan Stable patient with abdominal signs CT scan (allowing non-operative Tx if appropriate)

Stab wounds  

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Penetrates peritoneum in 2/3 cases Only 50-70% of these have significant visceral or vascular injury Selective laparotomies to reduce morbidity and hospital stay in haemodynamically stable patients Diagnostic aids: Wound exploration DPL Laparoscopy Serial examinations

Lumbar and flank wounds 

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Significantly less risk (<15%) for intra-abdominal injuries than those with anterior wounds A more selected approach is warranted Contrast enhanced CT scan combined with serial examinations is recommended Renal injuries occur in 6-8%

Management approach for penetrating abdominal trauma 

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Sensitivity of CT or US are far too low to exclude intra-abdominal injury Stab wounds Peritoneal penetration → Laparotomy Diagnostic laparoscopy ± Laparotomy Wound exploration ± Laparotomy Gunshot wounds Obligatory laparotomy Diagnostic laparoscopy ± Laparotomy

Incidence of IAI requiring exploratory laparotomy

Spleen

Blunt % 47

Penetrating % 7

Liver

51

28

Pancreas / Duodenum Colon

10

11

5

23

Stomach / Small bowel

9

42

Management “Prioritization” 

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Concurrent head injuries An exsanguinating abdominal injury demands a laparotomy to control bleeding before assessment of the HI Pelvic fracture Rapid application of external fixator to stabilize the pelvis before laparotomy

Non-operative management of solid organ injury 

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Increasing evidence to support nonoperative Mx Parallels with the wide-spread use of CT Clinical criteria (not CT grading) are used for decision making Must be continuously monitored in HDU or ICU setting

Criteria for non-operative Mx      

Solid organ injury shown on CT scan Minimal abdominal signs Haemodynamically stable Requires <2 units of blood HDU or ICU available Surgeons committed for repeated evaluation

Success rate of non-operative Mx 

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Liver 50-80% Spleen 93% for minor injuries Renal Majority can be Mx conservatively unless there is injury to renal pedicle or massive damage

Intervention radiology 

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Angiography ± embolization Both diagnostic and therapeutic Common use Pelvic fracture with bleeding uncontrolled by fixation Solid organ injury

Damage control surgery 

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10% trauma patients cannot tolerate definitive procedure at initial laparotomy Survival benefit demonstrated with the use of “damage control” approach Control bleeding Injured bowel stapled without anastomosis Solid organ injury packed Abdomen rapidly closed with towel clips or plastic bag

Indications for damage control   

Hypothermia ≤ 350C Acidosis pH <7.2 Coagulopathy Definitive surgery is deferred for 2448 hrs when resuscitation in ICU has corrected these physiological parameters

Abdominal compartment syndrome 

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ACS: A group of adverse progressive physiological effects of raised intraabdominal pressure Abdominal trauma is the commonest cause Pressure required to precipitate ACS is unknown (varies with individuals) Most will require decompression at 25-35 cmH2O

Predisposing factors in trauma patients  

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Massive intra-abdominal bleeding Visceral edema (ischaemiareperfusion) Vigorous fluid resuscitation Surgery Packing

Pathophysiology  

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Diaphragmatic splinting (Resp) Pressure on IVC (Decreases venous return and thus cardiac output) Oliguria (Direct renal compression +/- reduced systemic blood flow) The condition is fatal unless treated before irreversible physiological insult occurs

Major systems affected   

Pulmonary Cardiovascular Renal

Treatment of ACS 

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Urinary manometry to monitor the intraabdominal pressure Nasogastric decompression Abdominal decompression Control of haemorrhage Evacuation of gauze packs and blood Delayed wound closure (temporary plastic wrap) Ventilatory support till definitive closure (optimally in 2-3 days time)

Thank you!

PhD. Qiu Xinguang   

[email protected] 0371-6511 5777 13803710710