SEARCH · PubMed Health

Results for “Pneumoperitoneum”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 109 records · Page 6Linked to original sources

PubMed2000

Oxidative stress in lung tissue induced by CO(2) pneumoperitoneum in the rat.

BACKGROUND: Clinical trials have found that the pneumoperitoneum has potentially hazardous side effects. The biochemical basis of organ injury induced by pneumoperitoneum is, however, not well defined. Since oxidative stress is believed to play an important role in many pathological conditions, we set out to examine oxidative stress markers in the lung, liver, kidney, and pancreas by using a rat model of laparoscopy with CO(2) pneumoperitoneum and comparing it to a group with gasless laparoscopy. METHODS: Malondialdehyde (for lipid peroxidation), protein-bound carbonyls (for protein oxidation), reduced and oxidized glutathione, and the neutrophil marker myeloperoxidase were evaluated in tissue homogenates at 2 h, 6 h, and 18 h after laparoscopy. Immunoblotting was used to analyze the modification of lung proteins by 4-hydroxynonenal at 6 h. RESULTS: Significant lipid peroxidation was found selectively in lungs at 2 h and 6 h after CO(2) pneumoperitoneum. This was accompanied by a loss of glutathione but only minor protein oxidation. Further, lung proteins were clearly modified by the aldehydic product of lipid peroxidation 4-hydroxynonenal. Myeloperoxidase in lungs increased continuously up to 18 h in both experimental groups, but there were higher levels in the group with pneumoperitoneum. CONCLUSION: Oxidative stress is likely to contribute to the impairment of pulmonary function after laparoscopic operations using a CO(2) pneumoperitoneum.

Analysis of Variance↗

PubMed2000

Time-related changes in hemodynamic parameters and pressure-derived indices of left ventricular function in a porcine model of prolonged pneumoperitoneum.

BACKGROUND: Advanced laparoscopic procedures require prolonged pneumoperitoneum. Increased intra-abdominal pressure causes a number of hemodynamic changes including a drop in cardiac output, but it is unclear whether there is a direct effect on cardiac contractility. In this experimental study, we sought to determine whether there is a direct impact of pneumoperitoneum on cardiac contractility. We also examined the time-related changes taking place during the insufflation period. METHODS: Six young pigs were anesthetized and mechanically ventilated. Pneumoperitoneum was established by insufflating carbon dioxide to a pressure of 15 mmHg and maintained for a period of 180 min. Hemodynamic parameters including left ventricular dP/dT were invasively recorded every 15 min. All hemodynamic changes were statistically evaluated, and parameters were correlated with time. RESULTS: Cardiac output decreased with insufflation from a baseline of 3.37 +/- 0.34 lt/min and reached the lowest value at 165 min of pneumoperitoneum (2.86 +/- 0.30 l/min; p = 0.023). Systemic vascular resistance (SVR) significantly increased from 2236 +/- 227 dyne/s/cm(5) to a maximum of 3774 +/- 324 dyne/s/cm(5) (p = 0.005). Left ventricular dP/dT maximum did not change significantly with insufflation. The decrease in cardiac output strongly correlated with the increase in SVR (r = -0.949). Time of insufflation correlated with cardiac output (r = -0.762) and dP/dT maximum (r = -0.727). CONCLUSIONS: Pneumoperitoneum at 15 mmHg negatively affects cardiac output without significantly affecting cardiac contractility. A significant increase in SVR appears to be the driving event for the decreased cardiac output. Prolonged pneumoperitoneum may have an additional negative effect on hemodynamic parameters.

Animals↗

PubMed2000

Intraperitoneal tumor growth is influenced by pressure of carbon dioxide pneumoperitoneum.

BACKGROUND: Several studies have indicated that the carbon dioxide (CO(2)) pneumoperitoneum during laparoscopy plays a role in the pathogenesis of port-site metastases. An experimental animal study was performed to investigate the impact of various pneumoperitoneum pressures on peritoneal tumor growth. METHODS: In this study, 36 male WAG rats were randomized into three groups; two groups with different pneumoperitoneum pressures (16 mmHg and 4 mmHg) and one group of gasless controls. After a pneumoperitoneum of 0.5 x 10(6) ml was established, 531 tumor cells were injected intra-abdominally and the pneumoperitoneum was maintained for 60 min. Peritoneal tumor growth was assessed on day 11 at autopsy. RESULTS: Peritoneal tumor growth in the 16-mmHg group was significantly greater than in the 4-mmHg group (p = 0.039) and the gasless group (p = 0.004). CONCLUSIONS: High-pressure CO(2) pneumoperitoneum stimulates intra-abdominal tumor growth. The use of low insufflation pressures in laparoscopic cancer surgery should be considered.

Animals↗

PubMed1998

Influence of acute hemorrhage and pneumoperitoneum on hemodynamic and respiratory parameters.

BACKGROUND: We examined the questions of whether resuscitated (compensated) acute hemorrhage enhances the negative effects of carbopneumoperitoneum on hemodynamic and respiratory parameters and whether pneumoperitoneum with helium has any advantages under these circumstances. Our investigation focused on the influence of acute hemorrhage with different gases on the cardiovascular and respiratory system as well as on hepatic and renal blood flow in a porcine model. METHODS: Cardiac and hemodynamic function were monitored via implantation of catheters in pulmonary artery, femoral vein, and artery. Renal and hepatic blood flow were recorded using a transonic volume flow meter placed at the renal and hepatic artery and portal vein. Twelve animals were randomly assigned to one insufflation gas (carbon dioxide [CO2] or helium [He]). Following baseline recordings, acute hemorrhage (20 ml/kg) was induced by continuous bleeding over 30 min. Animals then received a colloidal solution (20 ml/kg 6% hydroxyethylstarch solution) over 30 min. Pneumoperitoneum of 12 mmHg was established, and all parameters were measured after 30 min of adaptation. The major endpoints of the study were cardiac output (CO), arterial pressure (MAP), systemic vascular resistance (SVR), and central venous pressure (CVP), as well as blood flow in hepatic and renal artery and portal vein. RESULTS: While CO and hemodynamic parameter as well as hepatic and renal blood flow were markedly reduced after hemorrhage, they returned nearly to their previous levels after resuscitation. Pneumoperitoneum with 12 mmHg did not further depress the cardiovascular system or reduce hepatic and renal blood flow. Pneumoperitoneum did not alter hepatic or renal blood flow. Pneumoperitoneum with helium did not substantially change the reaction of the cardiovascular system after resuscitated hemorrhage. CONCLUSIONS: If hemorrhage is compensated by proper resuscitation and hypovolemia is avoided, laparoscopic surgery with pneumoperitoneum of 12 mmHg appears to be not harmful. Using helium as the insufflating gas had no clear advantage over the carbon dioxide model.

Acute Disease↗

PubMed2003

Less impaired cell-mediated immune response in the murine peritoneal cavity after CO(2) pneumoperitoneum.

PURPOSE: We compared changes in the populations of peritoneal T lymphocytes and natural killer (NK) cells after CO(2) pneumoperitoneum and laparotomy to clarify whether pneumoperitoneum affects cell-mediated immune responses in the peritoneal cavity. METHODS: We analyzed and compared populations of T lymphocytes and NK cells among peritoneal exudative cells (PECs) collected from 185 female mice subjected to pneumoperitoneum, laparotomy, or anesthesia only. PECs were collected postoperatively, and the populations of T lymphocytes and NK cell subsets were analyzed by flow cytometry. The NK cell cytotoxicity (NKCC) of PECs and splenocytes was measured. RESULTS: The populations of CD3(+), CD4(+), and CD8(+) lymphocytes in the PECs continued to increase up until postoperative day (POD) 7 after laparotomy. The CD4/8 ratio on POD 3 was significantly lower after laparotomy than after pneumoperitoneum. The percentages of NK cells in the pneumoperitoneum group were significantly lower than those in the laparotomy group. On POD 1, the NKCC of splenocytes was less impaired in the pneumoperitoneum group than in the laparotomy group (10.3% vs 5.0%, P << 0.05). CONCLUSION: Laparoscopic surgery is preferable to open surgery because it results in less impairment of systemic and intraperitoneal cell-mediated immune responses.

Animals↗

PubMed2005

Anuria during pneumoperitoneum in infants and children: a prospective study.

INTRODUCTION: Transient oliguria during laparoscopic surgery is a known phenomenon. Currently, no data on the impact of pneumoperitoneum on renal function in children are available. PATIENTS AND METHODS: Thirty children with normal kidney function, who underwent laparoscopic surgery, were included in a prospective study. A transurethral catheter was placed to measure urine output during and 6 hours after operation. Renal blood flow (resistive index) was evaluated by Doppler ultrasound of a segmental renal artery before surgery, every 15 minutes during laparoscopy, and after 24 hours. Blood and urine samples were studied before and 24 hours after surgery. Hemodynamic parameters were monitored continuously during standardized anesthesia, including a standardized intravenous infusion regimen. RESULTS: Urine output decreased within 45 minutes of pneumoperitoneum in all patients. Of 8 children younger than 1 year, 7 (88%) developed anuria vs 3 of 22 (14%) children aged 1 to 15 years (P < .001). Nine children 1 year and older (32%) developed oliguria. There was a significant recovering in the mean urine output until 5 to 6 hours after pneumoperitoneum in both age groups. No significant alterations of the renal blood flow (resistive index) and the serum and urine levels of cystatin C, creatinine, and urea nitrogen were evident until 24 hours postoperatively. The volume of infusion during pneumoperitoneum did not correlate with urine output. CONCLUSION: Pneumoperitoneum leads to anuria in most children younger than 1 year and to oliguria in about one third of older children. This is a completely reversible phenomenon. Urine output should not be taken into consideration for calculating intravenous fluid administration during pneumoperitoneum in children.

Age Factors↗

PubMed2006

Carbon dioxide pneumoperitoneum prevents intraperitoneal adhesions after laparotomy in rats.

PURPOSE: The aim of this study was to assess whether carbon dioxide insufflation (CDI) pneumoperitoneum prevents intraperitoneal adhesions (IPAs). METHODS: Laparotomy was performed in 40 8-week-old Lewis rats and their bowels delivered through the wound and manipulated. The rats were divided into 4 groups, namely, those that would have laparotomy (Lp group, n = 15), Lp with CDI (Lp-CDI group, n = 15), Lp and bowel anastomosis (LpBA group, n = 5), and LpBA with CDI (LpBA-CDI group, n = 5). LpBA and LpBA-CDI group rats had 1 cm of ileum excised and end-to-end anastomosis performed. To accelerate IPA formation, all rats then had their bowels heated to 45 degrees C for 40 seconds and 0.5 mL of Lewis rat blood spilled over them. Rats in the control group (n = 5) had Lp alone without heating or blood spillage. Pneumoperitoneum involved insufflating carbon dioxide into the peritoneal cavity through a cannula at the time of final abdominal closure to create pneumoperitoneum to a pressure of 5 mm Hg. All rats had relaparotomy 10 days after surgery and IPAs were assessed blindly using an IPA severity score (IPASS: 0 = no adhesions, 1 = no serosal tears during adhesiolysis, 2 = serosal tears during adhesiolysis, 3 = bowel perforation during adhesiolysis). Only the worst IPA in each rat was scored. Rats were killed after the peritoneum and bowels were excised for histopathology. RESULTS: Pneumoperitoneum resolved in approximately 5 days. There were no associated side effects. The Lp-CDI group had significantly lower IPASS than the Lp group (0.23 +/- 0.46 vs 1.07 +/- 1.18, P < .05), and the LpBA-CDI group had significantly lower IPASS than the LpBA group (1.50 +/- 0.61 vs 2.40 +/- 0.55, P < .05). Histopathology showed pneumoperitoneum had no effect on the peritoneum or bowels. CONCLUSIONS: Our results suggest that CDI pneumoperitoneum appears to prevent IPA, especially between bowel-bowel IPA.

Animals↗

PubMed1999

The effects of carbon dioxide pneumoperitoneum on seeding of tumor in port sites in a rat model.

OBJECTIVES: The use of laparoscopic surgical techniques for the resection of intraperitoneal malignancies has been rapidly increasing in recent years; concomitantly, tumor recurrences at trocar sites have also been reported. These reports bring into question the appropriateness of pneumoperitoneum and laparoscopic techniques for carcinoma removal. We hypothesized that the carbon dioxide pneumoperitoneum and instrumentation used during laparoscopic procedures contribute to a greater incidence of tumor implantation into the ventral peritoneal wall wound sites than seen with laparotomy. This study, which used port placement and carbon dioxide pneumoperitoneum in an animal model, was designed to determine the relative incidences of tumor implantation into wound sites of the ventral peritoneal wall for laparoscopy and laparotomy. STUDY DESIGN: Viable MAT B III rat mammary adenocarcinoma cells were injected into the lower right quadrant of the peritoneal cavity of Fisher 344 rats (1 x 10(5) cells/rat). The animals were then divided into 4 groups: 1 group (n = 9) served as a control group and received no further manipulations; another (n = 8) underwent a midline laparotomy; another (n = 8) had four 18-gauge trocars inserted into the peritoneal cavity; and the last (n = 8) underwent induction of a 7- to 8-mm Hg carbon dioxide pneumoperitoneum in addition to the insertion of four 18-gauge trocars. All animals were maintained under surgical conditions for 2 hours. Animals were killed at 7 days, and the ventral peritoneal wall was examined for macroscopic evidence of tumor formation. RESULTS: A total of 32 possible sites of tumor implantation were measured. The control group showed no significant macroscopic evidence of tumor translocation to the ventral peritoneal wall. Among the 32 measured sites the laparotomy group had an overall lower incidence of tumor implantation at the peritoneal wall wound sites (n = 5) than did the group with the trocars alone (n = 20) group (P =.003) and the group with trocars plus carbon dioxide insufflation (n = 29, P <.0001). The group with trocars alone had a lower incidence of tumor implantation than did the group with trocars plus carbon dioxide pneumoperitoneum (P =.02). CONCLUSIONS: Trocar use during laparoscopic surgical procedures led to greater translocation of free tumor cells to peritoneal wall wound sites than did laparotomy in this animal model. The addition of carbon dioxide pneumoperitoneum further increased implantation of tumor cells at trocar sites. These results provide evidence that the use of laparoscopic techniques for resection of intraperitoneal malignancy needs further long-term study.

Adenocarcinoma↗

PubMed2003

Role of hypoxia inducible factors 1alpha and 2alpha in basal adhesion formation and in carbon dioxide pneumoperitoneum-enhanced adhesion formation after laparoscopic surgery in transgenic mice.

OBJECTIVE: To evaluate the role of hypoxia inducible factors (HIFs) 1alpha and 2alpha in adhesion formation after laparoscopic surgery. DESIGN: Prospective, randomized study. SETTING: Academic research center. ANIMAL(S): Forty Swiss/129SvJ wild-type mice and transgenic mice partially deficient for the genes encoding for HIF-1alpha (HIF-1alpha(+/-)) or HIF-2alpha (HIF-2alpha(+/-)). INTERVENTION(S): Adhesions were induced by standardized lesions during laparoscopy. To evaluate "basal adhesions" and "pneumoperitoneum-enhanced adhesions," the pneumoperitoneum was maintained for a minimum (10 minutes) or prolonged (60 minutes) period, respectively. MAIN OUTCOME MEASURE(S): Adhesions were blindly scored after 7 days. RESULT(S): In both HIF-1alpha and HIF-2alpha wild-type mice, pneumoperitoneum enhanced adhesion formation. In comparison with wild-type mice, basal adhesions were lower in HIF-1alpha(+/-) and similar in HIF-2alpha(+/-) mice. Pneumoperitoneum did not enhance adhesion formation in HIF-1alpha(+/-) or in HIF-2alpha(+/-) mice. Therefore, in comparison with the correspondent wild-type mice, pneumoperitoneum-enhanced adhesions were lower in HIF-1alpha(+/-) and HIF-2alpha(+/-) mice. CONCLUSION(S): These data confirm that CO(2) pneumoperitoneum enhances adhesion formation and indicate that this effect is mediated, at least in part, by an up-regulation of HIF-1alpha and HIF-2alpha.

Animals↗

PubMed2002

Pathogenesis of CO(2) pneumoperitoneum-induced metabolic hypoxemia in a rabbit model.

STUDY OBJECTIVE: To investigate the effects of carbon dioxide (CO(2)) pneumoperitoneum-induced changes in blood gases, acid-base balance, and oxygen homeostasis in rabbits. DESIGN: Prospective, randomized, controlled study (Canadian Task Force classification I). SETTING: University training and teaching center. SUBJECTS: Twenty-six adult female New Zealand white rabbits. INTERVENTION: Anesthesia and pneumoperitoneum. MEASUREMENTS AND MAIN RESULTS: In anesthetized rabbits arterial blood gases, acid-base balance, oxygenation values, and lactate concentrations were assayed during 2 hours. Spontaneous breathing, superficial and optimal ventilation without pneumoperitoneum, and with pneumoperitoneum at low (6 mm Hg) and higher (10 mm Hg) insufflation pressures were compared. The CO(2) pneumoperitoneum profoundly affected blood gases, acid-base balance, and oxygen homeostasis. Carboxemia with increasing end-tidal CO(2) and partial pressure of CO(2) (p <0.001), acidosis with decreasing pH (p <0.001), and base deficiency with decreasing actual base excess (p <0.001), standard base excess and standard bicarbonate and acid excess with increasing hydrogen bicarbonate (p <0.05 and <0.01) were found. Desaturation (p <0.01) with decreasing oxyhemoglobin p <0.05) and hemoglobin oxygen affinity (p <0.01) were also found. Carboxemia with acidosis was more pronounced with higher (p <0.01) than with lower (p >0.05) intraperitoneal pressures, and also with spontaneous breathing (p <0.05) and superficial ventilation (p <0.001) than with optimal ventilation, resulting in metabolic hypoxemia. CONCLUSION: In superficially ventilated and spontaneously breathing rabbits, CO(2) pneumoperitoneum profoundly affected blood gases, acid-base balance, and oxygen homeostasis, resulting in metabolic hypoxemia. With optimal ventilation and low intraperitoneal pressure carboxemia, respiratory acidosis, and changes in oxygen metabolism were minimal.

Acid-Base Equilibrium↗

PubMed2002

Effect of CO(2) pneumoperitoneum on ventilation-perfusion relationships during laparoscopic cholecystectomy.

BACKGROUND: Previous studies have shown that pneumoperitoneum transiently reduces venous admixture as assessed by a calculation based on the shunt formula, and increases arterial oxygen tension (PaO(2)) in patients without heart or lung disease. The aim of the present study was to further explore the relationship between ventilation-perfusion (V(A)/Q) before and during pneumoperitoneum by using the multiple inert gas technique. METHODS: Nine patients without heart or lung disease (ASA I), with a mean age of 42 years, scheduled for laparoscopic cholecystectomy were included. After premedication and induction of anaesthesia, radial artery and pulmonary artery catheters were introduced percutaneously. The V(A)Q relationships were evaluated by the multiple inert gas elimination technique before and during pneumoperitoneum to obtain a direct measure of the pulmonary shunt. RESULTS: Induction of pneumoperitoneum decreased the pulmonary shunt from 5.8 (4.5) to 4.1 (3.2)% (P<0.05) and increased PaO(2) from 21.7 (5.9) to 24.7 (4.8) kPa (P<0.01). During surgery, the shunt increased from 3.2 (2.8) to 5.2 (3.4)% to the same level as before pneumoperitoneum induction. No area with low V(A)Q was seen. Dead space ventilation amounted to 20.0 (1.2)% in the supine position and did not change during the investigation. CONCLUSIONS: In patients without heart or lung disease, pneumoperitoneum at an intra-abdominal pressure level of 11-13 mmHg causes a transient reduction of the pulmonary shunt. The mechanisms underlying the present finding remain to be elucidated.

Adult↗

PubMed2002

Changes in hemodynamics and autonomic nervous activity in patients undergoing laparoscopic cholecystectomy: differences between the pneumoperitoneum and abdominal wall-lifting method.

BACKGROUND AND STUDY AIMS: Intraoperative changes in circulatory hemodynamics and autonomic nervous activity were evaluated in 33 patients with cholelithiasis who underwent laparoscopic cholecystectomy. PATIENTS AND METHODS: Of these patients, 18 were treated using a pneumoperitoneum (group G) and 15 using the abdominal wall-lifting method (group WL). Their ECG, blood pressure, arterial oxygen saturation, and expiratory carbon dioxide partial pressure were monitored. Autonomic nervous function was evaluated by spectral analysis of the heart rate. RESULTS: Mean blood pressure increased significantly in group G during surgery, but did not vary in group WL during any stage of surgery. The high-frequency (HF) power, an index of parasympathetic activity, decreased significantly in group G after pneumoperitoneum. However, the HF power did not decrease significantly in group WL. The LF/HF ratio, an index of sympathetic activity, increased significantly in group G after pneumoperitoneum, but did not vary in group WL. In addition, the incidence of ventricular or supraventricular arrhythmias and the severity of the arrhythmias as determined by Lown's classification were higher in group G than in group WL. These findings suggest that intraoperative changes in autonomic nervous activity, due to increased intra-abdominal pressure, were smaller in patients undergoing laparoscopic cholecystectomy using the abdominal wall-lifting method than in those undergoing laparoscopic cholecystectomy using pneumoperitoneum. The results also demonstrated that hemodynamic changes were smaller in patients undergoing the abdominal wall-lifting method than in those undergoing pneumoperitoneum. CONCLUSIONS: It was concluded that hemodynamics should be carefully monitored during pneumoperitoneum, and that the abdominal wall-lifting approach in laparoscopic cholecystectomy is a method worthy of consideration for elderly patients or those with cardiopulmonary complications.

Abdominal Muscles↗

PubMed2005

Comparison of carbon dioxide and room air pneumoperitoneum for day-case diagnostic laparoscopy.

Laparoscopic examination is useful in the evaluation of infertile women. To perform this test, pneumoperitoneum is required to distend the abdomen, improve visibility and displace the intestines out of the pelvis. Several gases have been used to achieve this purpose including nitrous oxide (N2O), carbon dioxide (CO2), helium, xenon and air. This is a prospective study in a private fertility centre comparing CO2 and room air pneumoperitoneum for diagnostic laparoscopy. Also the safety of room air was evaluated. One hundred and forty five patients received CO2 (group 1, n=73) or room air (group 2, n=72) pneumoperitoneum. Ketamine anaesthesia was used for all the patients and the cost of the procedure was same for the study. CO2 pneumoperitoneum offered better visibility during laparoscopy and the patients also had a better outcome: Wound infection (CO2-2/73: 2.7% Vs. Air-11/72: 15.3%); abdominal discomfort (feeling of retained gas in the abdomen) CO2-5/73: 6.9% Vs. Air-61/72: 84.7%) and shoulder pain (CO2-0/73; 0.0% Vs. Air-56/72: 77.8%). Group 1 patients returned to normal activity earlier (1.5 days +/- 1.3 SD Vs. 4.8 days +/- 2.1 SD). We conclude that CO2 pneumoperitoneum has a better outcome than Air especially for day-case diagnostic laparoscopy. However, room Air pneumoperitoneum is safe, cheap, and available and may be recommended for low resource settings.

Air↗

PubMed2005

Effects of enalaprilat on the renin-angiotensin-aldosterone system and on renal function during CO2 pneumoperitoneum.

BACKGROUND AND PURPOSE: Mechanical and hormonal factors have been implicated in pneumoperitoneum-induced renal alterations. The aim of this study was to evaluate the effects of enalaprilat (Vasotec) administration on renal function during CO2 pneumoperitoneum, given that this drug, which is an angiotensin-converting enzyme inhibitor, by inhibiting the renin-angiotensin-aldosterone system, alters hormone-induced changes during pneumoperitoneum. MATERIALS AND METHODS: Thirty adult dogs were randomly assigned to one of three groups (N = 10 each): group A (pneumoperitoneum not performed); group B (CO2 + enalaprilat); group C CO2 only. The groups were analyzed with consideration for body weight, hematologic values, hemodynamic parameters, and renal function (plasma renin activity, urinary debt, creatinine clearance, and sodium-excretory fraction). RESULTS: Hemodynamic and acid-basic parameter differences did not influence renal function. Plasma renin activity decreased significantly in group B compared with group C and stayed close to the values in group A. Creatinine clearance remained constant in group B, while in group C, creatinine clearance dropped, and this difference was statistically significant. Urinary debt and sodium-excretory fraction increased in group B during pneumoperitoneum and 60 minutes after this period in comparison with the other groups without reaching statistical significance. CONCLUSION: The decline in urinary debt and in creatinine clearance observed during pneumoperitoneum was less accentuated with administration of enalaprilat.

Angiotensin-Converting Enzyme Inhibitors↗

PubMed2005

Is pneumoperitoneum harmful during intra-abdominal hemorrhage in rats?

BACKGROUND: Laparoscopic surgical interventions are being used in trauma patients for diagnostic and therapeutic purposes, but there are limited studies on this subject. The effect of pneumoperitoneum during intra-abdominal hemorrhage has not been elucidated. The aim of this study was to investigate the hemodynamic, respiratory, and renal effects of pneumoperitoneum in the splenic injury/ hemorrhagic shock model in rats. MATERIAL AND METHODS: In this study, 80 anesthetized Wistar male rats (294.5 +/- 31.2 g) were randomized into 2 main groups: nontraumatized (group A) and traumatized (group B). After initial preparation and monitoring, each group was divided according to the degree of pneumoperitoneum. The nontraumatized subgroups were A1, sham-operated; A2, 4-8 mm Hg; A3, 9-13 mm Hg; and A4, 14-18 mm Hg. The traumatized subgroups were B1, splenic injury without pneumoperitoneum; B2, B3, and B4, splenic injury with pneumoperitoneum at 4-8 mm Hg, 9-13 mm Hg, and 14-18 mm Hg, respectively. Mean arterial pressure, heart rate, and respiratory rate were monitored continuously. Blood samples were obtained for hemoglobin, hematocrit, arterial blood gases, and biochemical analyses. Twenty-four hour urine output was collected. RESULTS: In group B4, pH, pCO2, and HCO3 levels were lower than in all other groups, while pCO2 and base deficit levels were significantly higher (P < 0.05). Both blood and urine analysis results showed that 24-hour urine output and the glomerular filtration rate of groups A4 and B4 were significantly lower (P < 0.05), while urinary osmolarity and fractional sodium excretion levels were significantly higher (P < 0.05). CONCLUSION: High-pressure pneumoperitoneum in splenically traumatized rats amplifies acidosis, decreases urine output, decreases glomerular filtration rate, and increases urinary osmolarity and fractional sodium excretion significantly.

Animals↗

PubMed2003

Pre-emptive lidocaine inhibits arterial vasoconstriction but not vasopressin release induced by a carbon dioxide pneumoperitoneum in pigs.

BACKGROUND: We assessed the preventive effects of i.v. or i.p. lidocaine administration on increases in vascular resistance produced by carbon dioxide pneumoperitoneum and related this to vasopressin release. METHODS: Carbon dioxide pneumoperitoneum (14 mm Hg intra-abdominal pressure) was performed in 32 anaesthetized young pigs and monitored using a pulmonary artery catheter. Animals received lidocaine 0.5% (0.5 mg kg(-1)) i.v. (n=9) or 2 ml kg(-1) i.p. (n=9) or saline (n=5) 15 min before the pneumoperitoneum and were compared with a control group (n=9). RESULTS: I.V. and i.p. lidocaine inhibited increases in mean systemic vascular resistance induced by the pneumoperitoneum [2109 (SD 935) and 2282 (895), respectively, vs 3013 (1067) dyne s(-1) cm(-5) in the control group]. Cardiac output was increased. Plasma lidocaine concentrations were threefold higher after i.p. administration than after i.v. administration. After pneumoperitoneum insufflation, plasma lysine-vasopressin concentrations increased in all groups (control 74%, saline 65%, i.p. lidocaine 57%, i.v. lidocaine 74%). CONCLUSIONS: I.V. and i.p. lidocaine blunted systemic vascular responses to carbon dioxide pneumoperitoneum in pigs, but without influencing vasopressin release.

Anesthetics, Local↗

PubMed2000

Hypoxaemia induced by CO(2) or helium pneumoperitoneum is a co-factor in adhesion formation in rabbits.

A prospective randomized trial in a rabbit model was performed to test the hypothesis that the increase in adhesion formation following prolonged pneumoperitoneum is mediated by peritoneal hypoxaemia. Laparoscopic standardized opposing lesions were performed in uterine horns and pelvic sidewalls by bipolar coagulation and CO(2) laser in six groups of eight animals. Pure CO(2) or helium pneumoperitoneum was used for 10 (groups I and IV) or 45 min (groups II and V) to confirm the effect of duration of pneumoperitoneum and 96% of CO(2) or helium with 4% of oxygen (group III and VI) for 45 min to assess the effect of the addition of oxygen. After 7 days, adhesion formation was scored by laparoscopy. By two-way analysis of variance, total, extent, type and tenacity of adhesion scores increased (P = 0.0003, P = 0.0004, P = 0.0004 and P = 0.004) with increasing duration of pneumoperitoneum and decreased (P = 0.02, P = 0.03, P = 0.01 and P = 0.05) with the addition of oxygen. No differences were found between CO(2) and helium. In conclusion these data confirm the effect of pneumoperitoneum upon adhesions and demonstrate its reduction by oxygen, strongly suggesting that the main cause of adhesion formation is the relatively superficial hypoxaemia produced by the pneumoperitoneum.

Acidosis↗

PubMed1997

Splanchnic and renal deterioration during and after laparoscopic cholecystectomy: a comparison of the carbon dioxide pneumoperitoneum and the abdominal wall lift method.

UNLABELLED: Carbon dioxide (CO2) pneumoperitoneum together with an increased intraabdominal pressure (IAP) induces a hemodynamic stress response, diminishes urine output, and may compromise splanchnic perfusion. A new retractor method may be less traumatic. Accordingly, 30 ASA physical status I or II patients undergoing laparoscopic cholecystectomy were randomly allocated to a CO2 pneumoperitoneum (IAP 12-13 mm Hg) (control) or to a gasless abdominal wall lift method (retractor) group. Anesthesia and intravascular fluids were standardized. Direct mean arterial pressure (MAP), urine output, urine-N-acetyl-beta-D-glucosaminidase (U-NAG), arterial blood gases, gastric mucosal PCO2, and intramucosal pH (pHi) were measured. Normoventilation was instituted in all patients. MAP increased (P < 0.001) only with CO2 pneumoperitoneum. Minute volume of ventilation had to be increased by 35% with CO2 insufflation. PaCO2 was significantly higher (P < 0.05) for 3 h postoperatively in the control group. Diuresis was less (P < 0.01) and U-NAG levels (P < 0.01) higher in the control group. The pHi decreased after induction of pneumoperitoneum up to three hours postoperatively and remained intact in the retractor group. We conclude that the retractor method for laparoscopic cholecystectomy ensures stable hemodynamics, prevents respiratory acidosis, and provides protection against biochemical effects, which reveal the renal and splanchic ischemia caused by CO2 insufflation. IMPLICATIONS: A mechanical retractor method (gasless) was compared with conventional CO2 pneumoperitoneum for laparoscopic cholestectomy. The gasless method ensured stable hemodynamics, prevented respiratory acidosis, and provided protection against the renal and splanchnic ischemia seen with CO2 pneumoperitoneum.

Adult↗