Measuring intra-abdominal pressure in the intensive care setting

Abstract

Increased intra-abdominal pressure (IAP) may occur in critically ill patients. The easiest method to estimate IAP at the bedside is the bladder pressure measurement. A standard procedure (same volume infused, pressure transducers, and patient's position) should be used to obtain comparable and reproducible data among different patients and during different stages and time of the disease. The increase in IAP leads to two major pathological conditions: 1) the intraabdominal hypertension (IAP above 16 cmH2O) and 2) the abdominal compartment syndrome (IAP above 30 cmH2O). Increased IAP negatively affects pulmonary, cardiovascular, renal, gastrointestinal and central nervous system function. Most of critically ill patients have an intraabdominal hypertension, while few of them (less than 5%) present clinical characteristics of abdominal compartment syndrome. IAP is different among different categories of patients. The highest mean values during intensive care unit stay have been reported in respiratory and cardiologic patients among medical categories and in neurologic patients among surgical patients. IAP seems to be correlated with severity scores but its relation to mortality is uncertain. Routine measurements of IAP by means of bladder pressure are not associated with an increased rate of urinary tract infections. Future trials are warranted to better evaluate the role of routine IAP measurements on clinical management of critically ill patients

Comparison of direct and indirect methods of intra‐abdominal pressure measurement in normal horses

“…Second, this site was chosen to allow for more accurate measurement of intra‐abdominal hypertension. Previous work has shown that the mass of the abdominal contents above the site of measurement influences the intra‐abdominal pressure measured 2,6,20,21 . Because the majority of gastrointestinal viscera lies beneath the cannula, the site selected should reduce error due to normal variations in abdominal fill, but still allow space above the cannula to measure any abnormal increase in intra‐abdominal pressure in future studies.…”

“…A pathological increase in pressure in the abdomen is described as intra‐abdominal hypertension in humans, and is defined by sustained or repeated measures of intra‐abdominal pressure >12 mm Hg 1 . With increased intra‐abdominal pressure, venous return and cardiac output decrease, and tissue perfusion is reduced 1,2 . Intra‐abdominal hypertension is an independent risk factor for multiple organ dysfunction, and organ failure resulting from intra‐abdominal hypertension is known as abdominal compartment syndrome 1,3 …”

“…Three causes of intra‐abdominal hypertension in human medicine include decreased body wall compliance (eg, tight abdominal closures), increased intra‐abdominal contents (eg, due to ileus, ascites, or hemoabdomen), as well as intra‐abdominal hypertension secondary to large volume resuscitation resulting in capillary leak syndrome, reperfusion injury, and cytokine release 2,4,5 . Similar risk factors for intra‐abdominal hypertension are present in equine patients, and recognition of intra‐abdominal hypertension in this species would allow for development of therapies to prevent multiorgan dysfunction from compartment syndrome.…”

Intra‐abdominal hypertension and the abdominal compartment syndrome

“…By decreasing venous return, intra‐abdominal hypertension may cause venous pooling and stasis, which predisposes to venous thrombo‐embolic disease. Appropriate mechanical and pharmacological measures must be taken to decrease the risks of pulmonary embolism [24].…”

Evaluation of gastric pressures as an indirect method for measurement of intraabdominal pressures in the horse

“…As the volume within the abdominal cavity increases, the compliance tends to decrease, eventually resulting in exponential increases in intraabdominal pressure for minor changes in intraabdominal volume 1,2 . This loss of compliance along with abnormally high intraabdominal pressure is termed intraabdominal hypertension 1,3–5 …”