Respiratory mechanics during laparoscopic cholecystectomy: the effects of the abdominal wall lift

Correlation between intra-abdominal pressure and pulmonary volumes after superior and inferior abdominal surgery

OBJECTIVE

Patients undergoing abdominal surgery are at risk for pulmonary complications. The principal cause of postoperative pulmonary complications is a significant reduction in pulmonary volumes (FEV1 and FVC) to approximately 65-70% of the predicted value. Another frequent occurrence after abdominal surgery is increased intra-abdominal pressure. The aim of this study was to correlate changes in pulmonary volumes with the values of intra-abdominal pressure after abdominal surgery, according to the surgical incision in the abdomen (superior or inferior).

METHODS

We prospectively evaluated 60 patients who underwent elective open abdominal surgery with a surgical time greater than 240 minutes. Patients were evaluated before surgery and on the 3rd postoperative day. Spirometry was assessed by maximal respiratory maneuvers and flow-volume curves. Intra-abdominal pressure was measured in the postoperative period using the bladder technique.

RESULTS

The mean age of the patients was 56 ± 13 years, and 41.6% 25 were female; 50 patients (83.3%) had malignant disease. The patients were divided into two groups according to the surgical incision (superior or inferior). The lung volumes in the preoperative period showed no abnormalities. After surgery, there was a significant reduction in both FEV1 (1.6 ± 0.6 L) and FVC (2.0 ± 0.7 L) with maintenance of FEV1/FVC of 0.8 ± 0.2 in both groups. The maximum intra-abdominal pressure values were similar (p=0.59) for the two groups. There was no association between pulmonary volumes and intra-abdominal pressure measured in any of the groups analyzed.

CONCLUSIONS

Our results show that superior and inferior abdominal surgery determines hypoventilation, unrelated to increased intra-abdominal pressure. Patients at high risk of pulmonary complications should receive respiratory care even if undergoing inferior abdominal surgery.

Impact of body position on respiratory mechanics in patients during laparoscopic surgery

AIM: To observe the effect of body position on respiratory mechanics in patients during laparoscopic surgery.

METHODS: Reserve trendelenburg position was adopted in 20 patients undergoing laparoscopic gastrectomy, while conventional trendelenburg position was adopted in 20 patients undergoing laparoscopic enterectomy. All patients were subjected to general anaesthesia, and controlled ventilation was selected. The compliance of the lungs (Cpat) and airway pressure (Paw) were monitored with the Drager primus anesthesia machine. PaCO₂ and PaO₂ were monitored with the Siemens Rapidlab1265 Blood Gas Analyzer. Measurements were divided into five distinct phases: 5 minutes after the induction of anesthesia (T1); 5 minutes after pneumoperitoneum (T2); 5 minutes after position change (T3); 5 minutes after adjusting ventilation parameters (T4); and 5 minutes after peritoneal deflation (T5). Respiratory mechanics were analyzed using SPSS15.0 statistics software.

RESULTS: PaCO₂ and Paw at T2 in the conventional trendelenburg group were significantly higher than those in the reserve trendelenburg group (both P < 0.05). PaO₂ and Cpat at T2 and T3 in the conventional trendelenburg group were significantly lower than those in the reserve trendelenburg group (all P < 0.01).

CONCLUSION: Body position can affect respiratory parameters during laparoscopic surgery.

Laparoscopic cholecystectomy with carbon dioxide pneumoperitoneum is safe even for high-risk patients

BACKGROUND

Because of absorbed carbon dioxide (CO(2)) and elevated intraabdominal pressure (IAP), CO(2) pneumoperitoneum (CO(2)PP) has potentially harmful intraoperative circulatory and ventilatory effects. Although not clinically significant for healthy patients, these effects are assumed to be deleterious for patients with a high risk for anesthesia (American Society of Anesthesiology [ASA] 3 and 4) and significant cardiopulmonary, renal, or hepatic diseases. The authors assessed CO(2)PP-related adverse effects by comparing ASA 3 and 4 patients who underwent laparoscopic cholecystectomy (LC) with or without CO(2)PP.

METHODS

A total of 20 successive ASA 3 and 4 patients who underwent LC were randomized into CO(2)PP (n = 10) and abdominal wall elevator (Laparolift) (n = 10) groups. The parameters for perioperative hemodynamics, ventilation, perfusion of intraabdominal organs, and blood chemistry were recorded periodically from before the induction of the anesthesia until postoperative day 2 and compared between the groups.

RESULTS

Mean age, height, weight, the proportional number of ASA 3 vs ASA 4 patients, the volume of perioperative fluid loading, and the dose of analgesics did not differ significantly between the groups. The length of the operation was 49.9 +/- 10.6 min for the CO(2)PP group and 50.6 +/- 17.2 min for Laparolift group (nonsignificant difference). The mean central venous pressure (CVP) 30 min after insufflation was higher (12.3 +/- 4.8 vs 7.9 +/- 3.7 mmHg) and the (Gastric Mucosal pH) pHi at the end of the operation was lower (7.29 +/- 0.07 vs 7.35 +/- 0.04) in the CO(2)PP group than in the Laparolift group (p < 0.05). Later, CVP and pHi did not differ significantly. Other parameters of hemodynamics including oxygenation, perfusion, and blood chemistry did not differ significantly.

CONCLUSIONS

For LC for patients with an ASA 3 and 4 risk for anesthesia, no significant adverse effects could be attributed to CO(2 )pneumoperitoneum. For high-risk patients, preoperative preparation and active perioperative monitoring are essential for safe anesthesia for LC with or without CO(2)PP.

The effect of low-flow sevoflurane and desflurane on pulmonary mechanics during laparoscopic surgery

BACKGROUND

This study was designed to investigate the effects of inhaled anesthetic agents on respiratory mechanics with low flow anesthesia in laparoscopic abdominal surgery. Two inhaled anesthetics, desflurane and sevoflurane, have a lower solubility in blood and tissues than all previous volatile anesthetics, and have become the preferred volatile anesthetics for routine surgical procedures.

METHODS

Twenty-six patients were examined. Patients were randomly assigned to two groups, to receive sevoflurane (n = 13) or desflurane (n = 13). Tidal volume and ventilation rate were kept unchanged throughout the operation. Intra-abdominal pressure was kept constant at the level of 12 mm Hg. Respiratory mechanics such as peak inspiratory pressure (PIP), respiratory resistance (Rr), and dynamic compliance (Cdyn) measurements were recorded by a Datex-Ohmeda respiratory device (Datex-Ohmeda, Finland) at four timepoints: 5 minutes after mechanical ventilation started (T1), after insufflation of the peritoneum (T2), in the 30-degree Trendelenburg position (T3), and after desufflation of the peritoneum (T4).

RESULTS

In our study, desflurane caused a statistically significant increase in PIP and Rr and decrease in C(dyn). When the two groups were compared, Rr values in the deslurane group showed significant increases at T2, T3, and T4 compared to the sevoflurane group (P < 0.05). These values did not change in the sevoflurane group, while PIP significantly increased at T2, T3, and T4 after desufflation in the desflurane group (P < 0.05). Cdyn values decreased significantly at all 4 timepoints in the desflurane group compared to the sevoflurane group (P < 0.05).

CONCLUSION

We concluded that respiratory mechanics were affected by desflurane with low flow anesthesia in patients undergoing laparoscopic abdominal surgery. No significant influence on respiratory mechanics was seen with sevoflurane anesthesia.

The effect of different levels of peritoneal CO2 pressure on bleeding time of spleen capsule injury

AIMS

The authors, in contrast to similar injuries with open surgery, had observed spontaneous hemostasis of relatively large spleen capsule injuries during laparoscopic surgery.

METHODS

Standard spleen injuries were carried out in 5 anesthetized mongrel dogs at different CO2 pressures and in open surgery. Bleeding was checked every minute by wiping around the injury but not removing the clot. Bleeding time was measured until no more oozing was detected. At every pressure level 3-3 measurements were done and analyzed. Parenchymal pressure of the spleen and systemic blood pressure were detected with direct catheter implantation.

RESULTS

In open surgery the average bleeding time was 15.2 min; at 5, 15, and 25 mmHg CO2 pressures bleeding times were 12.3, 10.6, and 9.8 min, respectively. The parenchymal pressure of the spleen (5-6 mmHg) rose synchronously with peritoneal pressure, but no significant changes in systemic blood pressure were seen.

CONCLUSION

Peritoneal CO2 pressure may counterweight the parenchymal pressure of the spleen, thus helping hemostasis. There seems to be an inverse proportion between peritoneal pressure and bleeding time. In case of spleen capsule injury during laparoscopic surgery, chances for spontaneous hemostasis are much better compared to open surgery. Attention must be paid to maintain adequate peritoneal pressure.

Hemodynamic and pulmonary changes during open, carbon dioxide pneumoperitoneum and abdominal wall-lifting cholecystectomy. A prospective, randomized study

BACKGROUND

Carbon dioxide (CO2) pneumoperitoneum effects are still controversial. The aim of this study was to investigate cardiopulmonary changes in patients subjected to different surgical procedures for cholecystectomy.

METHODS

In this study, 15 patients were assigned randomly to three groups according to the surgical procedure to be used: open cholecystectomy (OC), CO2 pneumoperitoneum cholecystectomy (PP), and laparoscopic gasless cholecystectomy (abdominal wall lifting [AWL]), respectively. A pulmonary artery catheter was used for hemodynamic monitoring in all patients. A subcutaneous multiplanar device (Laparo Tenser) was used for abdominal wall lifting. To avoid misinterpretation of results, conventional anesthesia was performed with all parameters, and the position of the patients held fixed throughout surgery. The following parameters were analyzed: mean arterial pressure (MAP), heart rate (HR), cardiac output (CO), cardiac index (CI), stroke volume index (SVI), central venous pressure (CVP), systemic vascular resistances index (SVRI), mean pulmonary arterial pressure (MPAP), pulmonary capillary wedge pressure (PCWP), pulmonary vascular resistances index (PVRI), peak inspiratory pressure (PIP), end-tidal CO2 pressure (ETCO)2, CO2 arterial pressure (PaCO2), and arterial pH.

RESULTS

All the operations were completed successfully. The Laparo Tenser allowed good exposition of the surgical field. A slight impairment of the cardiopulmonary functions, with reduction of SVRI, MAP, and CI and elevation of pulmonary pressures and vascular resistance, followed induction of anesthesia. However, these effects tended to normalize in the OC and AWL groups over time. In contrast, CO2 insufflation produced a complex hemodynamic and pulmonary syndrome resulting in increased right- and left side filling pressures, significant cardiac index reduction, derangement of the respiratory mechanics, and respiratory acidosis. All of these effects normalized after desufflation.

CONCLUSIONS

Cardiopulmonary adverse effects of general anesthesia were significant but transitory and normalized during surgery. Carbon dioxide pneumoperitoneum caused a significant impairment in cardiopulmonary functions. In high-risk patients, gasless laparoscopy may be preferred for reliability and absence of cardiopulmonary alterations.