Blunt trauma to the abdomen produces a spectrum of clinical findings which include 1.) symptoms of cage injury which include bruising and pain which worsens with tensing of the abdominal musculature or straight leg raising; 2.)symptoms of occult intra-abdominal injury characterized by tenderness on palpation which improves with tensing of the abdominal musculature, situps, and straight leg raising; 3.)symptoms of severe intra-abdominal injury which include guarding, rigidity, absent bowel sounds, abdominal distention, tympany. Flank pain or swelling may indicate a kidney injury or retroperitoneal hematoma. Peritoneal signs consisting of guarding or rigidity can also be present in a bladder injury. Abdominal distension, ecchymoses of the flank and around the umbilicus can indicate intraabdominal bleeding. Severe intra-abdominal injury can also cause respiratory depression and hypovolemic shock.
Stab wounds to the abdomen may result in shock peritonitis or evisceration. In evisceration it is essential to cover the area with moist saline towels and start the patient on iv antibiotics. If either of these three are present the patient deserves an operation. If these three are absent, the wound must be explored and traced under local anesthesia. If there is no penetration of fascia the patient will not need an operation. However if the fascia is penetrated the patient may need an operation because underlying structures may be injured and have a slow leak. There are two techniques useful in evaluating this situation. One is simple observation by a surgeon, the second is quantitative diagnostic peritoneal lavage.
There are a number of useful tests which can be used in evaluating abdominal trauma. In general all patients with blunt abdominal trauma should have serum electrolytes, liver function tests, amylase, creatinine and BUN. A urinalysis and stool guaiac should be done.Blood tests may reveal a falling hematocrit indicative of intraabdominal bleeding; an elevated white blood cell count present in peritonitis, or injury to spleen; an elevated amylase present in pancreatic injury, abnormal liver function tests present in liver injury. Abnormal BUN and Creatinine may indicate kidney injury. Red blood cells in the urine may indicate an injury to the kidney ureters or bladder. Radiographic studies include a flat and upright of the abdomen which may show an ileus, or free air under the diaphragms which indicate bowel injury or perforated viscus, a ground glass appearance which may indicate intraperitoneal hemorrhage, absence of the psoas margin. The psoas is a muscle in the retroperitoneum which is the space in which the kidneys are enclosed. If the edge of the psoas is obscured this may indicate free blood in the retroperitoneum and points to kidney injury. More advanced xray studies include IVP. In the emergency department, iv contrast can be given at the time of the initial abdominal film in order to visualize the kidneys and ureters. A complete IVP and cystogram would also check for a bladder rupture. An IVP may show absence of blood flow to kidney due to arterial injury, anatomical deformity of the kidney or even leakage from the urinary collecting system which includes the ureters, the tubes leading brom the kidneys to the bladder and the bladder itself. If the patient is stable a CAT scan can reveal an aortic aneurysm, solid organ injury including pancreas, liver and kidney, urinary dysfunction using IV contrast, GI dysfunction or injury using oral contrast. An angiogram can be performed in the stable patient to further study vascular injuries such as to the renal artery. Local exploration of a penetrating wound to the abdomen has already been mentioned. Peritoneal lavage can be performed in which a catheter is surgically inserted just under the umbilicus and a liter of Normal saline is allowed to run into the abdomen. A sample of this is allowed to run out. It is then examined for fat gloubules, blood, bile and sometimes amylase. If these are positive the patient may need an operation. Peritoneal lavage is most useful in blunt abdominal trauma, but can be used in penetrating trauma in which case it is called quantitative peritoneal lavage. An ng tube should be considered in evaluation of abdominal trauma in general. The initial aspirate is tested for guaiac and examined for blood, bile or other abnormalities. A Foley catheter can also be used to monitor urine output, and obtain prompt specimens of urine.
The history and mechanism of injury are important. One should investigate into the accident or form of trauma. The speed of the car, the damage to the car, site of impact, whether the patient struck the steering wheel or dash. Attention should be paid to associated injuries. Occult intra-abdominal injury can be masked by other injuries such as severe head injury or blunt trauma to the chest. Conversely severe abdominal pain may lead the evaluation away from other serious injuries such as the spine. In general trauma requires a complete physical exam and adherence to acls and atls guidelines in order to avoid the very distinct possibility of overlooking an injury.
In general fractured lower ribs point to splenic or hepatic injury. Fractures of ribs 10 11 and 12 on the left should occasion evaluation of the spleen. Fractures of ribs 11 and 12 on the right are associated with a significant incidence of hepatic injury. The internal organs can be evaluated by flat plate, CT scan, ultrasound, or peritoneal lavage. The CBC may show leucocytosis or a falling hematocrit. Liver function tests may be abnormal in liver injury.