Abdominal Compartment Syndrome – A Silent but Lurking Danger!
Posted Aug 07 2011 12:07am
Abdominal Compartment Syndrome and Intra-abdominal Hypertension are two sides of the same coin. While Intra-abdominal Hypertension exists when intra-abdominal pressure exceeds the normal level which is set between 20 to 25 mmHg, Abdominal compartment syndrome is said to exist when intra-abdominal hypertension is accompanied by manifestations of organ dysfunction, which dramatically reduces upon abdominal decompression. The organ systems commonly involved include the pulmonary, cardiovascular, renal, splanchnic, musculoskeletal/integumentary (abdominal wall), and the central nervous system.
Severe blunt and penetrating abdominal trauma
Ruptured abdominal aortic aneurysms
Massive fluid resuscitation
Accumulation of blood and clot
Forced closure of a noncompliant abdominal wall
Circumferential abdominal burn eschars
Incidence among those with identifiable risk is 14%, while the incidence following primary closure after repair of ruptured abdominal aortic aneurysm was found to be 4%.
In the trauma population, those patients undergoing abbreviated or “Damage Control” laparotomy, particularly those with intra-abdominal packing are at an increased risk. Interestingly, an open abdomen does not necessarily mean total absence of the risk of this syndrome.
Respiratory Failure that is characterized by impaired pulmonary compliance resulting in elevated airway pressures with progressive hypoxia and hypercapnia. High airway pressures may be needed in this scenario to overcome the high extrathoracic pressure exerted through the diaphragm and not to overcome an intrinsic lung problem. The earliest manifestations of this syndrome may be a subtle pulmonary dysfunction or an elevated peak airway pressure. Elevated hemidiaphragms with a loss of lung volume may be the only sign in an otherwise innocuous patient.
Haemodynamic Indicators: Elevated heart rate, hypotension, elevated pulmonary artery wedge pressure and central venous pressure, reduced cardiac output, and elevated systemic and pulmonary vascular resistance. A decreased venous return is central to the pathophysiology of abdominal compartment syndrome.
Renal function impairment is manifested as oliguria progressing to anuria with resultant azotemia. It is only partly reversible by fluid resuscitation.
Raised intracranial pressure is also another clinical manifestation.
Intra-abdominal Hypertension is present when intra-abdominal pressure exceeds 20 mmHg
Direct measurement of intra-abdominal pressure by means of an intraperitoneal catheter
Bedside measurement can be achieved by transduction of pressures from indwelling femoral vein, rectal, gastric, and urinary bladder catheters. Of these, measurement of urinary bladder pressure and gastric pressures are the most common and easily accessible.
Intragastric pressure measurements are taken from an indwelling nasogastric tube. This varies within 2.5 cm H2O or 1.84 mmHg (conversion factor 1 cm H2O = 0.736 mmHg) of urinary bladder pressures.
In 1984, Kron et al. described a method to measure intra-abdominal pressure at the bedside with the use of an indwelling Foley Catheter as follows:
Abdominal Compartment Syndrome is best prevented and any existing predisposing factor is looked into and prevented if possible. It is an important component in the critically ill patients and those with blunt abdominal trauma. One must remember that renal failure due to abdominal compartment syndrome does not respond to fluid resuscitation and should trigger us to consider it in the differential diagnosis. It is imperative that the clinician remains alert to this silent but lurking danger that is Abdominal Compartment Syndrome.