What is Normal Intra-Abdominal Pressure?

Abstract

The causes and effects of increased intra-abdominal pressure and abdominal compartment syndrome have been well documented. However, there have been no large series to determine normal intra-abdominal pressure in hospitalized patients. The purpose of this study was to determine normal intra-abdominal pressure in randomly selected hospitalized patients and to identify factors that predict variation in normal intra-abdominal pressure. A total of 77 patients were prospectively enrolled between September 1998 and July 1999. Data obtained included patient demographics (i.e., age, gender, height, weight, and body mass index), reason for hospitalization and bladder catheterization, previous and current surgical status, comorbidities, and intra-abdominal pressures. Intra-abdominal pressure readings were obtained through an indwelling transurethral bladder (Foley) catheter. Data were analyzed by analysis of variance and multiple regression analysis. There were 36 females and 41 males with a mean age of 67.7 years. Average weight, height, and body mass index were 79.6 kg, 1.70 m, and 27.6 kg/m2, respectively. Mean intraabdominal pressure was 6.5 mm Hg (range 0.2–16.2 mm Hg). Body mass index was positively related to intra-abdominal pressure ( P < 0.0004). Gender, age, and medical and surgical histories did not significantly affect intra-abdominal pressure. However, using multiple regression analysis, a relationship between intra-abdominal pressure, body mass index, and abdominal surgery was discovered. Intra-abdominal pressure is related to a patient's body mass index and influenced by recent abdominal surgery. Thus, the normal intra-abdominal pressure can be estimated in hospitalized patients by using the derived equation. Knowledge of the expected intra-abdominal pressure can then by used in recognizing when an abnormally high intra-abdominal pressure or abdominal compartment syndrome exists.

Effects of pneumoperitoneum and patient position on intracranial pressure in obese patients undergoing laparoscopic cholecystectomy

“…Obese patients tolerate laparoscopic procedures very well. The normal intra-abdominal pressure of non-obese individuals is 5 mm Hg or lower [20]. In contrast, morbidly obese patients have chronically high intra-abdominal pressures of 9 to 10 mmHg [21].…”

Pelvic Floor Pressures Differ Based on Location in the Pelvis and Body Position: A Cadaver Mode

“…UDS measured sitting and supine measurements, which were consistent with normative in vivo findings, supporting the validity of the model [ 17 , 18 ]. Reported intraabdominal pressure readings obtained similarly through a Foley catheter were 6.5 mm Hg with a range of 0.2–16.2 mm Hg [ 19 ], and in various body positions at 9.5 cm H 2 O for supine, 11.5 cm H 2 O at 30 degrees, and 14 cm H 2 O at 45 degrees. In addition, intravaginal measurement of intraabdominal pressures have been reported at 27.5 cm H 2 O [ 20 ] and in the supine position at 1.5 cm H 2 O [ 21 ].…”

“…They noted increased abdominal pressures in obese patients and did not report measurements at rest. Several studies measured visceral pressures as a surrogate for abdominal pressures, and they found that obesity increased abdominal pressure [ 19 , 22 , 23 ]. This effect of increased weight in the viscera, seen in truncal obesity, supports the idea that the small bowel plays a role in pressure applied to the pelvic floor.…”

“…The magnitude of our UDS pressure recordings are in line with previously reported findings, suggesting that the overall findings are at least reasonably comparable with the pressures one could expect from living subjects. More detailed and less invasive pressure recording approaches will be needed before these findings can be replicated on pre-mortem patients [ 19 , 20 , 21 , 22 , 23 ]. The potential applications of these results may demonstrate that lower lumbar lordosis treatment can alleviate pelvic floor dysfunction.…”

Low-Flow Acute Kidney Injury

“…The kidney is a primary target of abdominal compartment syndrome as it is so dependent on high blood flow, and AKI from this syndrome is primarily mediated by reductions in renal blood flow, resulting in prerenal azotemia. The normal intra-abdominal pressure is approximately 6 mm Hg, is dependent on body mass, and can reach as high as 10-15 mm Hg chronically in morbidly obese individuals without causing abdominal compartment syndrome (24,25). Therefore, the level of intra-abdominal pressure cannot be used for a strict definition for abdominal compartment syndrome.…”