Does Prolonged Pneumoperitoneum Affect Oxidative Stress Compared with Open Surgical Procedures?

Synchronous abdominal tumors: is combined laparoscopic surgery in a single approach a safe option?

Background and Purpose:

Recent advances in cancer treatment have resulted in bet- ter prognosis with impact on patient's survival, allowing an increase in incidence of a second primary neoplasm. The development of minimally invasive surgery has provided similar outcomes in comparison to open surgery with potentially less mor- bidity. Consequently, this technique has been used as a safe option to simultaneously treat synchronous abdominal malignancies during a single operating room visit. The objective of this study is to describe the experience of two tertiary cancer hospitals in Brazil, in the minimally invasive treatment of synchronous abdominal neoplasms and to evaluate its feasibility and peri-operative results.

Materials and Methods:

We retrospectively reviewed the data from patients who were submitted to combined laparoscopic procedures performed in two tertiary hospitals in Brazil from May 2009 to February 2015.

Results:

A total of 12 patients (9 males and 3 females) with a mean age of 58.83 years (range: 33 to 76 years) underwent combined laparoscopic surgeries for the treatment of at least one urological disease. The total average duration of surgery was 339.8 minutes (range: 210 to 480 min). The average amount of intraoperative bleeding was 276.6mL (range: 70 to 550mL) and length of hospitalization was 5.08 days (range: 3 to 10 days). Two patients suffered minor complications regarding Clavien system during the immediate postoperative period.

Conclusions:

Combined laparoscopic surgery for the treatment of synchronous tumors is feasible, viable and safe. In our study, there was a low risk of postoperative morbidity.

Selected oxidative stress markers in gynecological laparoscopy

INTRODUCTION

The surgical stress response after laparoscopy is smaller when compared with open surgery, and it is expected that after minimally invasive surgery the possible development of oxidative stress will be less severe.

AIM

To evaluate markers of pro-oxidant activity - levels of lipid peroxides and malondialdehyde - and activity of the antioxidant enzymes superoxide dismutase and glutathione peroxidase in the perioperative period in patients undergoing gynecological laparoscopy and to determine whether the duration of laparoscopy can affect these changes.

MATERIAL AND METHODS

The study included 64 patients, divided into two groups: group 1 with duration of laparoscopy up to 20 min, and group 2 with duration of the operation over 40 min. Blood samples were collected before anesthesia, 5 min after release of pneumoperitoneum, and 10 h after surgery.

RESULTS

A statistically significant increase in the levels of lipid peroxides and malondialdehyde in samples collected after surgery was found in comparison with values obtained before surgery. Also statistically significant differences existed between groups of patients with different duration of surgery. Superoxide dismutase and glutathione peroxidase activity values were significantly decreased. They were also significantly different between the two groups with different duration of surgery.

CONCLUSIONS

In our study, levels of the markers of pro-oxidant activity increased and levels of the markers of antioxidant enzymes decreased, suggesting development of oxidative stress. The duration of laparoscopic procedures affects the severity of the presented changes.

Inflammatory and oxidative stress after surgery for the small area corrections of burn sequelae

PURPOSE

To compare vitamin levels, inflammatory and oxidative stress markers before and after skin autograft surgery to correct burn scar areas.

METHODS

This prospective study was conducted with 8 patients with a median age of 28 years (range, 16 to 40 years) that had burn sequelae and were admitted to a Burn Unit for correction of small burn scar areas [3.3 (1.0-5.0) % of the corporal surface]. The volunteers were evaluated before and 48 hours after excision of scar tissue and skin autograft. Routine laboratory data, along with a food questionnaire and anthropometry were collected in the preoperative period. Serum vitamin A, C, E, B(12) and folic acid levels, inflammatory markers (C-protein reactive, alpha-1-acid glycoprotein, ferritin) and oxidative stress markers (reduced glutathione - GSH and Thiobarbituric Acid Reactive Substances - TBARS) were determined at preoperative and postoperative phases. Data were analyzed with two-sample Wilcoxon test.

RESULTS

All volunteers were clinically stable and had adequate nutritional status at admission. After surgery, C-reactive protein serum levels increased [0.4 (0.01-1.0) vs. 2.5 (0.6-4.7) mg/dL, p=0.01] and vitamin A levels decreased [3.4 (2.1-4.2) vs. 2.4 (1.6-4.1) µmol/L, p=0.01]. No changes occurred in other vitamins, ferrritin, alpha-1-acid glycoprotein, GSH and TBARS levels.

CONCLUSION

Minimal metabolic changes were produced after skin autograft in small areas of well-nourished patients without active infection or inflammation.

Oxidative stress in laparoscopic versus open abdominal surgery: a systematic review

BACKGROUND

Any form of trauma, including surgery, is known to result in oxidative stress. Increased intra-abdominal pressure during pneumoperitoneum and inflation-deflation may cause ischemia reperfusion and, hence, oxidative stress may be greater during laparoscopic surgery. The aim of this study was to systemically review the literature to compare oxidative stress in laparoscopic and open procedures.

METHODS

A systematic search of the Medline, Pub Med, EMBASE, and Cochrane databases was performed with the following keywords: pneumoperitoneum AND surger $ OR laparoscop $ AND oxida $. The search was limited to articles published between 1980 and August 2010.

RESULTS

The initial search identified 197 papers. After review of the abstracts, 17 papers met the inclusion criteria. Six more papers were identified through the reference lists. It was not possible to perform a meta-analysis due to heterogeneity of patient data, patient selection criteria, and diversity of biomarkers used. The majority of studies demonstrated greater immediate oxidative stress after open surgery. There was, however, a paucity of studies comparing open versus laparoscopic surgery with regards to tissue oxidative stress.

CONCLUSION

Laparoscopic surgery seems to produce less systemic oxidative stress. However the effect of pneumoperitoneum on local oxidative stress and tissue hypoxia and its clinical significance need further investigation.

Evaluation of antioxidant parameters in rats treated with sevoflurane

BACKGROUND AND OBJECTIVES

Sevoflurane is a halogenated fluorinated ether that undergoes hepatic biotransformation through cytochrome P4502E1. Halogenated ethers undergoing biotransformation by P4502E1 can produce reactive oxygen species (ROS), weakening the antioxidant defense mechanism. The objective of this study was to investigate the relationship between the activity of erythrocyte antioxidant enzymes and sevoflurane.

METHODS

Animals were divided in four groups: Group 1 - control: 100% oxygen (1 L.min(-1) for 60 min during five consecutive days); Group 2 - 4.0% sevoflurane in 100% oxygen (1 L.min(-1) for 60 minutes during five consecutive days); Group 3 - isoniazid (i.p.), 50 mg.kg(-1)/ day for four consecutive days, followed by 100% oxygen (1 L.min(-1) for 60 minutes during four consecutive days); Group 4 - intraperitoneal isoniazid, 50 mg.kg(-1) daily for four days, followed by 4.0% sevoflurane in 100% oxygen (1 L.min(-1) for 60 minutes during five days). Twelve hours after the last exposure to sevoflurane, animals were sacrificed and their blood was collected through the portal vein for analysis of antioxidant enzymes.

RESULTS

An increase in the activity of glucose-6-phosphate dehydrogenase and a decrease in the activity of catalase were observed, especially in the group of animals pre-treated with isoniazid. Changes in the activity of glutathione peroxidase were not observed.

CONCLUSIONS

The interaction between sevoflurane and cytochrome P450 2E1 with enzymatic inducers can lead to oxidative stress with prolonged and repetitive exposure.

Management of mechanical ventilation during laparoscopic surgery

Laparoscopy is widely used in the surgical treatment of a number of diseases. Its advantages are generally believed to lie on its minimal invasiveness, better cosmetic outcome and shorter length of hospital stay based on surgical expertise and state-of-the-art equipment. Thousands of laparoscopic surgical procedures performed safely prove that mechanical ventilation during anaesthesia for laparoscopy is well tolerated by a vast majority of patients. However, the effects of pneumoperitoneum are particularly relevant to patients with underlying lung disease as well as to the increasing number of patients with higher-than-normal body mass index. Moreover, many surgical procedures are significantly longer in duration when performed with laparoscopic techniques. Taken together, these factors impose special care for the management of mechanical ventilation during laparoscopic surgery. The purpose of the review is to summarise the consequences of pneumoperitoneum on the standard monitoring of mechanical ventilation during anaesthesia and to discuss the rationale of using a protective ventilation strategy during laparoscopic surgery. The consequences of chest wall derangement occurring during pneumoperitoneum on airway pressure and central venous pressure, together with the role of end-tidal-CO2 monitoring are emphasised. Ventilatory and non-ventilatory strategies to protect the lung are discussed.