Hemodynamic and arterial blood gas changes during carbon dioxide and helium pneumoperitoneum in pigs

Abstract

The effects of pneumoperitoneum with carbon dioxide and helium on systemic hemodynamics and arterial blood gases were investigated in pigs in an attempt to clarify the mechanisms by which pneumoperitoneum may induce organ dysfunction. A total of 16 anesthetized female pigs underwent pneumoperitoneum with carbon dioxide or helium (n = 8 each) in a stepwise fashion to intraabdominal pressures of 8, 10, 12, 16, and 20 mmHg. Changes in cardiac output; renal and hepatic blood flow; mean arterial, mean pulmonary arterial, mean pulmonary arterial wedge, inferior vena caval, and portal venous pressures; and total peripheral resistance were measured. Arterial blood samples were obtained at the same time the above parameters were determined. Urine volume was measured as an indicator of renal function. Pneumoperitoneum with either carbon dioxide or helium significantly increased venous pressures and simultaneously decreased cardiac output. These changes were associated with decreases in organ blood flow due to increased peripheral resistance. Urinary output was reduced to a similar degree in the two groups. Blood gas analysis revealed pneumoperitoneum-induced metabolic acidosis in both groups, although hypercapnia was observed only in the carbon dioxide group. These findings suggest that pneumoperitoneum-related organ dysfunction may be due to increased intraperitoneal pressure rather than to hypercapnia.

Cardiac function during laparoscopic vs open gastric bypass

“…Absorption of CO 2 can lead to an increased PaCO 2 , which induces myocardial depression, increased catecholamine, and vasodilatation. However, Shuto et al [16] showed that helium insufflation also reduced CO, which suggested that increased intraabdominal pressure might be, in part, the cause for reduced CO. In the present study, PaCO 2 levels at 3 h after surgical incision were significantly higher for laparoscopic GBP than for open GBP (42.1 ± 4.8 vs 36.6 ± 4.4 mmHg, p ‫ס‬ 0.001).…”

Cardiopulmonary changes during laparoscopy and vessel injury: comparison of CO 2 and helium in an animal model

“…Helium did not influence tumor growth in vivo in recent experimental studies [6,7,8]. Additionally, intraabdominal insufflation of helium had no negative effects on respiratory function and caused only minor changes of hemodynamic function [2,3,4,9,10]. Nevertheless, low solubility of helium raised the question of whether or not helium increases the effects of gas embolism during laparoscopy and accidental injury of large venous vessels.…”

“…It has been reported in recent experimental studies that helium does not influence tumor growth in vivo [6,7,8]. Additionally, intraperitoneal insufflation of helium had no negative effects on respiratory function and caused only minor changes in hemodynamic function [4,9,10]. Nevertheless, helium is not used in the clinical setting because it is thought to increase the effects of gas embolism, owing to the low solubility of this gas.…”

Estudo da função hepática de ratos espontaneamente hipertensos submetidos a diferentes pressões de pneumoperitônio com CO2

“…Entretanto, existem vários trabalhos que avaliam o fluxo sangüíneo portal, da artéria hepática e da microcirculação hepática na vigência de pneumoperitônio (5,23,27,28) . Os efeitos do aumento da pressão intra-abdominal na circulação hepática foram estudados em alguns modelos experimentais (2,6,30,31) . Diebel et al (28) estudaram a sua repercussão sobre a perfusão hepática, em suínos, mostrando uma redução em função do aumento da pressão intra-abdominal.…”

“…Além disso, parece haver também influência hormonal, como a elevação da vasopressina relatada por Punnonem et al (32) , em pacientes submetidas à laparoscopia ginecológica. Mann et al (31) , em estudo experimental com porcos, mostraram que a insuflação com CO 2 promoveu a liberação de vasopressina, o que, por sua vez, levou a distúrbios hemodinâmicos. Estes autores concluíram que as mudanças hemodinâmicas observadas durante o pneumoperitônio de CO 2 estavam relacionadas aos efeitos bioquímicos do gás CO 2 e que eram, primariamente, mediados pelo aumento da concentração plasmática de vasopressina (22) .…”