Principles of trauma management (Proceedings)
The principles surrounding the initial approach to the patient with abdominal trauma are similar to those in a patient that has sustained any form of trauma. Rapid assessment of the cardiovascular and respiratory systems should be performed, and the presence of shock should be identified. If physical examination findings are supportive of shock (tachycardia, pale mucous membranes, poor pulse quality), then a large bore intravenous catheter should be placed and fluid therapy should be initiated promptly. Regardless of the nature or severity of the abdominal injury, treatment of shock should take priority in the first few minutes after arrival to the clinic.
While in some instances the presence of abdominal trauma may be easily identified with physical examination alone (when external wounds are present), attention to detail or a raised index of suspicion may be required to identify subtle clues suggestive of abdominal trauma. The presence of wounds or bruising over the abdomen should alert the clinician to the potential for internal injuries. Abdominal distension may indicate the presence of a hemo- or uro-abdomen. Abdominal pain, while a non-specific finding, may be an early indicator of abdominal trauma. Bruising or swelling in the caudal inguinal area can be associated with urinary tract rupture. A soft fluctuant swelling under the skin may be indicative of a body wall hernia. Simple tests including packed cell volume and total solids, and blood urea nitrogen can be helpful and should be performed in every patient that has sustained trauma.Hemoabdomen
Blood loss into the abdominal cavity is a common sequel to vehicular trauma. The source of bleeding is most often secondary to liver or splenic rupture, but can be due to less common causes such as avulsed renal artery or a fractured kidney. Pale mucous membranes should alert the clinician as to the possibility of blood loss, although poor perfusion secondary to shock and volume contraction must also be considered. In general, the presence of a hemoabdomen should be suspected in any patient that presents with signs of shock but without signs of external blood loss. Physical examination finding of a distended abdomen is supportive of hemoabdomen, although a significant amount of abdominal hemorrhage is possible before signs of abdominal distension occur. The initial PCV/TS can be helpful in identifying blood loss when the initial physical examination unremarkable. Although blood loss typically causes a reduction in PCV and TS, a normal PCV in the dog with a hemoabdomen is possible due to splenic contraction. Evaluation of the TS often provides subtle clues as to the presence of blood loss. A total protein of less than 6.0g/dl should raise the index of suspicion of blood loss in the trauma patient. The astute emergency clinician is constantly re-evaluating the trauma patient, and a repeat minimum data base (PCV/TS, BG, Azo) often confirms the initial suspicion of internal blood loss (reduced PCV and reduced TS). A lack of serosal detail on abdominal radiographs may support the presence of hemoabdomen, although a significant amount of effusion must be present before this change becomes obvious. The presence of a hemoabdomen can be confirmed with abdominocentesis, with the PCV of the abdominal blood matching or exceeding the peripheral PCV.
In most cases, patients with traumatic hemoabdomen are successfully managed medically. Treatment for shock should proceed as in any trauma patient to restore perfusion. In some cases, aggressive resuscitation may increase blood pressure sufficiently to worsen intra abdominal bleeding, and highlights the need for constant re-evaluation of the patient. In many cases a full 'shock dose' of intravenous fluids may not be necessary to restore perfusion, and the fluid therapy should be tailored to the patient to avoid over-resuscitation. Abdominal counter pressure may be applied using abdominal bandages, although this is contraindicated in patients with respiratory difficulty or a diaphragmatic hernia. Surgical management of the patient with hemoabdomen is indicated when hemodynamic instability persists despite fluid resuscitation and administration of blood products.