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Increased oxidative stress and gut ischemia caused by prolonged pneumoperitoneum in patients undergoing robot-assisted laparoscopic radical prostatectomy
Acta Anaesthesiologica Taiwanica 49 (2011) 46e49
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Acta Anaesthesiologica Taiwanica journal homepage: www.e-aat.com
Original Article
Increased oxidative stress and gut ischemia caused by prolonged pneumoperitoneum in patients undergoing robot-assisted laparoscopic radical prostatectomy Chiao-Fen Luo 1, Yung-Fong Tsai 1, 2, 3, Chia-Hung Chang 1, Chun-Te Wu 4, Huang-Ping Yu 1, 2 * 1
Department of Anesthesiology, Chang Gung Memorial Hospital, Taoyuan, Taiwan, R.O.C. College of Medicine, Chang Gung University, Taoyuan, Taiwan, R.O.C. Graduate Institute of Clinical Medical Sciences, Chang Gung University, Taoyuan, Taiwan, R.O.C. 4 Department of Urology, Chang Gung Memorial Hospital, Keelung, Taiwan, R.O.C. 2 3
a r t i c l e i n f o
a b s t r a c t
Article history: Received 2 March 2011 Received in revised form 28 April 2011 Accepted 4 May 2011
Objective: To investigate changes in plasma oxidative stress markers associated with prolonged pneumoperitoneum during robot-assisted laparoscopic radical prostatectomy (RALP). Methods: In all, patients of ASA Physical Status IIeIII who intended to undergo RALP were enrolled in the study. Arterial plasma levels of malondialdehyde (MDA) and intramucosal pH were measured 1 minute before and at 1 hour, 2 hours, 3 hours, and 4 hours after the introduction of pneumoperitoneum at an insufflation pressure of 15 mmHg; likewise, they were again measured every 10 minutes after deflation for 60 minutes, at 2 hours and 12 hours after deflation. Results: The mean duration of pneumoperitoneum was around 4 hours. After induction of pneumoperitoneum, the MDA concentrations were significantly elevated at various time points as compared with the preinsufflation value. Significant increase of MDA value was noted also 30 minutes after deflation as compared with the pre-deflation levels. The intramucosal pH value decreased significantly after CO2 insufflation compared with the preinsufflation values. It also increased significantly 2 hours after CO2 deflation as compared with the pre-deflation values. Conclusion: A prolonged pneumoperitoneum in RALP results in decreased splanchnic blood flow. Pneumoperitoneum itself produces oxidative stress, and ischemia-reperfusion model after deflation of pneumoperitoneum produces more oxidative stress. Copyright Ó 2011, Taiwan Society of Anesthesiologists. Published by Elsevier Taiwan LLC. All rights reserved.
Key words: gastric mucosa; hydrogen-ion concentration; malondialdehyde; pneumoperitoneum, artificial; reperfusion injury
1. Introduction Minimally invasive surgery has seen tremendous growth. In 2000, Binder and Kramer1 performed the first robot-assisted laparoscopic radical prostatectomy (RALP), which is a promising minimally invasive surgical approach with possible reduced blood loss, fewer blood product transfusions, shorter care in postanesthesia unit, and shorter hospital stay.2,3 Although laparoscopic surgery is generally considered safe, increased intra-abdominal pressure associated with pneumoperitoneum during laparoscopic procedures greatly impairs the splanchnic perfusion as a result of compression. The detrimental effects of increased intra-abdominal pressure on the hepatic arterial, mesenteric, and intestinal mucosal * Corresponding author. Department of Anesthesiology, Chang Gung Memorial Hospital, No. 5, Fu-Shin Street, Kwei-Shan, Taoyuan 333, Taiwan, R.O.C. E-mail: [email protected] (H.-P. Yu).
blood flows have been described in several studies.4,5 An ischemiareperfusion human model has been observed during and soon after laparoscopic surgery.6e9 After deflation of pneumoperitoneum, intra-abdominal pressure and splanchnic blood flow normalize, thereby representing the reperfusion phase. Clinical manifestations of ischemia-reperfusion injuries are diverse and may include myocardial hibernation/stunning, reperfusion arrhythmias, impaired cerebral function, breakdown of the gastrointestinal barrier, systemic inflammatory response syndrome, and multiorgan dysfunction syndrome.10 Previous studies have documented the impact of CO2 pneumoperitoneum on oxidative stress during laparoscopic cholecystectomies and minor gynecological surgeries.11,12 The duration of the pneumoperitoneum involved in these previous studies was roughly 1 hour. The severity of pneumoperitoneum-induced oxidative stress is suggested to be time dependent.13 However, data for long-term pneumoperitoneums are very limited.
1875-4597/$ e see front matter Copyright Ó 2011, Taiwan Society of Anesthesiologists. Published by Elsevier Taiwan LLC. All rights reserved. doi:10.1016/j.aat.2011.05.010
Prolonged pneumoperitonium-induced increased oxidative stress and gut ischemia
Gastric intramucosal pH (pHi) reflects splanchnic perfusion and oxygenation.14 Its obtainment is minimally invasive, and its measurement is effective for assessing tissue oxygenation adequacy.14 Reactive oxygen species, which damage cellular components and initiate the lipid peroxidation process, are responsible for ischemia-reperfusion injuries.6 Harmful oxidative reactions may occur in organisms so that they are removed by means of enzymatic and nonenzymatic antioxidative mechanisms.11 Malondialdehyde (MDA) is regarded to be the most reliable and producible markers of oxidative stress in the clinical setting.13 The main source of MDA is the peroxidation of polyunsaturated fatty acids with two or more methylene-interrupted double bonds.15 It is referred to as potentially mutagenic and atherogenic because of its interaction with DNA and proteins.15 The aim of the current study was to evaluate the alterations in oxidative stress and splanchnic perfusion during prolonged pneumoperitoneum in RALP. A prospective clinical study was designed, and plasma levels of MDA-lipid peroxidation marker and gastric pHi were measured. 2. Methods 2.1. Patients The study protocol was approved by the ethics committee of Chang Gung Memorial Hospital (IRB 98-2998B, Taoyuan, Taiwan). All patients provided written informed consent. Twelve adult patients whose physical statuses were graded as ASA Status II or III were recruited. The RALP was carried out by a single surgeon. Exclusion criteria included a history of sepsis or shock, cardiopulmonary disease clinically, tobacco smoking, or recent antioxidant or vasoconstrictor use. 2.2. Study protocol General anesthesia was induced intravenously with fentanyl (3 mg/kg), midazolam (0.2e0.3 mg/kg), and rocuronium (0.5e 0.6 mg/kg). A 20-gauge arterial catheter was inserted into the left brachial artery after the induction of anesthesia for blood sampling and arterial blood pressure monitoring. After tracheal intubation, anesthesia was maintained with isoflurane in oxygen at 1e1.5 end-tidal concentration, and the arterial blood pressure was kept within 20% of its preinduction value. The lungs were mechanically ventilated with pressure-controlled ventilation to maintain the end-tidal CO2 at 30e40 mmHg. Bolus dose of rocuronium (0.2 mg/kg) was given every 30 minutes during surgery. Intraoperative electrocardiogram, pulse oximetry, central venous pressure, and arterial blood pressure were constantly monitored. After skin closure, patients were extubated in the operating room. Pneumoperitoneum was created by intraperitoneal insufflation of CO2 with the patient in the supine position. Patients were then placed in the steep Trendelenburg position (30 from horizontal). Intraperitoneal pressure was maintained at 15 mmHg during the induced pneumoperitoneum. 2.3. Measurement Blood samples containing sodium heparin as anticoagulant were obtained for MDA measurements. Baseline value was obtained 1 minute before inducing the pneumoperitoneum. After pneumoperitoneum establishment, blood samples were collected 1 hour after and at 1-hour intervals during the procedure. At the end of the surgery, blood samples were obtained 10 minutes after the deflation of CO2 and at 10-minute intervals for 1 hour, and then
47
at 2 hours and 12 hours after the deflation of CO2. Blood samples for MDA analysis were centrifuged (3500 rpm, 10 minutes) and the supernatants were immediately stored at 80 C until the analysis was performed within 1 week. The MDA content was measured by a thiobarbituric acid assay to estimate the lipid peroxidation products. MDA was treated with thiobarbituric acid to form a colored complex. We measured the levels of thiobarbituric acid reactive substances by adopting the method reported by Yoshioka et al16 Briefly, 0.5 mL plasma, 2.5 mL thiobarbituric acid (200 g/L), and 1 mL TBA (6.7 g/L) were mixed together and boiled for 30 minutes. Two milliliters of butanol was added to the tubes, and the colored supernatant was extracted after centrifugation at 3000 rpm. The absorbance of the supernatant was spectrophotometrically measured at 535 nm. The MDA concentration was expressed in micromoles per mg protein (mmol/mg protein). The plasma level of MDA in each sample was analyzed by enzyme-linked immunoabsorbent assay and reported as femtograms per milligram of protein (fg/mg protein). After the induction of anesthesia, a double-lumen tonometric nasogastric tube (Tonometrics Catheter; Datex-Ohmeda, Helsinki, Finland) was inserted to the stomach. The correct position of the tube was confirmed by positive aspiration of gastric juice. To calculate pHi, arterial blood and gastric juice samples were collected 1 minute before the insufflation of CO2, 1 hour after the insufflation of CO2, at 1-hour intervals thereafter during the procedure, 10 minutes after deflation, at 10-minute intervals until 1 hour after deflation, and 2 hours after deflation of CO2. The pHi was estimated indirectly by the PCO2 measured in the stomach lumen and the bicarbonate concentration measured in the arterial blood with the Henderson-Hasselbalch’s equation.17
h
HCO 3
i
pHi ¼ 6:1 þ log PCO2 0:031 2.4. Statistical analysis All data are presented as mean standard deviation. Calculation and data analysis were performed using SPSS version 17.0 (SPSS Inc., Troy, NY, USA). The levels of MDA and pHi were analyzed and compared using the Wilcoxon signed-rank test. Differences were considered to be statistically significant if p < 0.05. 3. Results Twelve patients with prostate cancer, who underwent RALP performed by a sole surgeon, were enrolled for the study. Demographic and clinical data are presented in Table 1. Data of blood pressure and heart rate during and after the surgery are presented in Table 2. 3.1. Malondialdehyde After CO2 insufflation, the plasma concentration of MDA, as a measure of free radical production, increased significantly as Table 1 Patient demographic characteristics. Variables
Mean standard deviation (n ¼ 12)
Age (y) Height (cm) Weight (kg) Body mass index (kg/m2) Duration of pneumoperitoneum (min)
61.9 8.6 165.3 6.4 73.4 10.7 26.8 3.5 287.2 38.8
48
C.-F. Luo et al
Table 2 Data of mean arterial pressure and heart rate during and after the surgery. Mean arterial pressure was kept within 20% of its preinduction value.
Mean arterial pressure (mmHg) Heart rate (beat/min)
Preinduction
Preinsufflation
þ1h
þ2h
þ3h
þ4h
96.0 16.6 72.3 9.8
78.3 14.6 65.1 16.1
88.4 6.9 64.5 9.7
86.3 5.0 67.8 13.7
86.3 7.3 70.2 15.7
83.4 9.1 70.5 15.4
Deflation
þ 10 min
þ 30 min
þ1h
þ2h
þ 12 h
Mean arterial pressure (mmHg) Heart rate (beat/min)
79.2 10.4 68.2 15.5
92.1 15.1 77.9 10.3
81.2 15.1 81.2 15.1
82.0 12.2 82.0 8.5
94.5 16.0 78.6 12.8
Data shown as the mean standard deviation.
In the present study, significant increase in MDA concentration and decrease in pHi value were observed after the induction of pneumoperitoneum. After deflation, an unexpected increase in MDA value was noted. A prolonged pneumoperitoneum of 4 hours could lead to decreased splanchnic blood flow and increased oxidative stress, not only during the pneumoperutineum but also after the deflation. Numerous outcome measures for oxidative stress can be used clinically, including endogenous antioxidant levels, peroxidation markers, derived gastric pHi, cytokine levels, and histological findings.13 Measurements of lipid peroxidation markers, especially MDA, are generally regarded to be most reliable and reproducible in
the clinical setting.13,15 The present data revealed that the maintenance of intra-abdominal CO2 pressure at 15 mmHg for 4 hours could induce a significant increase in oxidative stress markers. There were two trends in regard to MDA changes throughout the surgery. One occurred during the pneumoperitoneum, and the other appeared after CO2 deflation. During the induced CO2 pneumoperitoneum, the plasma MDA level was significantly higher than its preinsufflation level. It peaked during the second hour and revealed a slight but insignificant decrease in the third and fourth hours. Previous studies suggested that the levels of oxidative stress markers associated with pneumoperitoneums could rise in a timedependent manner.13,18 The CO2 insufflation pressure in our study was constant throughout the surgery, but the MDA level did not continuously increase during the third and fourth hours. The MDA level appeared to achieve homeostasis after being subject to pneumoperitoneum for 2 hours. No other study has evaluated oxidative stress markers during such a long pneumoperitoneum duration. To the best of our knowledge, there are no studies in this regard in prolonged pneumoperitoneum (i.e. 3 hours or 4 hours). In our speculation, there might be some substances that were produced to resist the lipid peroxidation process as time went by. After CO2 deflation, MDA values increased steadily and reached a peak 30 minutes after deflation, which was significantly higher than that during CO2 insufflation. Various studies have investigated the ischemia-reperfusion injury that occurs as a result of pneumoperitoneum.6,7,11,12 Pneumoperitoneum for laparoscopic surgery at intra-abdominal pressure of 12e15 mmHg is much higher than the normal pressure of the portal system (7e10 mmHg). Previous experimental and human studies have shown that CO2 pneumoperitoneum impairs splanchnic perfusion by compressing vessels.5 Portal venous flow is also reduced during laparoscopic procedures,19 and there have been several reports about intestinal ischemia after
Fig. 1. Plasma MDA level in patients undergoing robot-assisted laparoscopic radical prostatectomy. Data are expressed as the mean standard deviation. Difference from preinsufflation value: *p < 0.05, **p < 0.01. Difference from pre-deflation value (þ4 hours after pneumoperitoneum): #p < 0.05. MDA ¼ malondialdehyde.
Fig. 2. pHi value in patients undergoing robot-assisted laparoscopic radical prostatectomy. Data are expressed as the mean standard deviation. Difference from preinsufflation value: *p < 0.05. Difference from pre-deflation value (þ4 hours after pneumoperitoneum): **p < 0.05. pHi ¼ intramucosal pH.
compared with the preinsuffltion value (Fig. 1). The mean peak value appeared 2 hours after CO2 insufflation (95.3 74.9 mmol/ mg), which was significantly higher than the mean baseline value (47.7 14.2 mmol/mg). After the deflation of CO2, MDA values demonstrated a slight but insignificant increase. The significant increase appeared 30 minutes after deflation (106.7 75.0 mmol/ mg) as compared with the pre-deflation levels (75.3 42.9 mmol/ mg). The MDA values nearly returned to baseline levels some 12 hours after CO2 deflation (Fig. 1). 3.2. Intramucosal pH The pHi values significantly decreased after CO2 insufflation as compared with the preinsufflation values. After deflation, the pHi values were still significantly lower than the preinsufflation values. Two hours after CO2 deflation, the pHi value increased and significantly differed as compared with the pre-deflation value (Fig. 2). 4. Discussion
Prolonged pneumoperitonium-induced increased oxidative stress and gut ischemia
laparoscopic procedures.20e23 These findings suggest that pneumoperitoneum for laparoscopic surgery, which consequentially raises the intra-abdominal pressure, may produce significant organ ischemia followed by reperfusion injury on deflation of the abdomen.24,25 Consistent with these findings, our results suggest that an ischemia-reperfusion injury would be present at the end of a prolonged induced pneumoperitoneum. A previous study in women who underwent laparoscopic enucleation of uterine myoma demonstrated increased levels of MDA immediately after surgery, which normalized 24 hours after surgery.26 In our study, plasma MDA levels normalized 12 hours after CO2 deflation. Fall of gastric pHi is an early indicator of inadequate splanchnic perfusion.13,17 It is based on the measurement of increased tissue CO2 production that accompanies anaerobic metabolism in the gut. The pHi is an estimate of the gastric mucosal CO2 and bicarbonate concentration in arterial blood. The pHi value was significantly decreased after CO2 insufflation in our study. Previous studies have reported a measurable and continuous reduction in gastric mucosal pH during laparoscopic cholecystectomy.27,28 These results indicate that splanchnic ischemia occurs during the induced pneumoperitoneum. In our study, the decrease in pHi persisted up to 1 hour after CO2 deflation. Koivusalo et al28 reported a decrease in pHi after the creation of a pnemoperitoneum for laparoscopic cholecystectomy, and this decrease persisted for up to 3 hours after CO2 deflation. Persistent decrease of pHi indicates that although the splanchnic blood flow increases after deflation, however, impaired splanchnic circulation persists even after the termination of the pneumoperitoneum. Decreased splanchnic blood flow and increased oxidative stress were observed during the existing pneumoperitoneum and after its deflation. The clinical relevance of oxidative stress after pneumoperitoneum is related to hepatic injury,29 lung injury,30 and renal injury.31 Light microscopy has also revealed histopathological findings concerning ischemia-reperfusion injuries in the liver and ileum.32,33 It is reported that hypoperfusion-reperfusion injury would initiate a wide and complex array of inflammatory responses that may aggravate local injury and induce impairment of remote organ function as well.34 Given the increasing complexity and duration of laparoscopic procedures, organ ischemia-reperfusion injury and oxidative stress associated with prolonged pneumoperitoneum may become more pervasive. In conclusion, a prolonged pneumoperitoneum of 4 hours results in decreased splanchnic blood flow and increased oxidative stress both during the pneumoperitoneum and after deflation. Although RALP is a promising and minimally invasive surgical approach with many advantages, the oxidative stress generated during a prolonged pneumoperitoneum should be noted. The clinical significance of prolonged pneumoperitoneum-associated oxidative stress and the impact of its reduction on defined clinical endpoints need further investigation. Acknowledgment This study was supported by Chang Gung Medical Grant (CMRPG390881). References 1. Binder J, Kramer W. Robotically-assisted laparoscopic radical prostatectomy. BJU Int 2001;87:408e10. 2. Coelho RF, Chauhan S, Palmer KJ, Rocco B, Patel MB, Patel VR. Robotic-assisted radical prostatectomy: a review of current outcomes. BJU Int 2009;104:1428e35. 3. Ficarra V, Cavalleri S, Novara G, Aragona M, Artibani W. Evidence from robotassisted laparoscopic radical prostatectomy: a systematic review. Eur Urol 2007;51:45e55. 4. Diebel LN, Wilson RF, Dulchavsky SA, Saxe J. Effect of increased intraabdominal pressure on hepatic arterial, portal venous, and hepatic microcirculatory blood flow. J Trauma 1992;33:279e82.
49 5. Eleftheriadis E, Kotzampassi K, Botsios D, Tzartinoglou E, Farmakis H, Dadoukis J. Splanchnic ischemia during laparoscopic cholecystectomy. Surg Endosc 1996;10:324e6. 6. Glantzounis GK, Tselepis AD, Tambaki AP, Trikalinos TA, Manataki AD, Galaris DA, et al. Laparoscopic surgery-induced changes in oxidative stress markers in human plasma. Surg Endosc 2001;15:1315e9. 7. Glantzounis GK, Tsimaris I, Tselepis AD, Thomas C, Galaris DA, Tsimoyiannis EC. Alterations in plasma oxidative stress markers after laparoscopic operations of the upper and lower abdomen. Angiology 2005;56:459e65. 8. Baysal Z, Togrul T, Aksoy N, Cengiz M, Celik H, Boleken ME, et al. Evaluation of total oxidative and antioxidative status in pediatric patients undergoing laparoscopic surgery. J Pediatr Surg 2009;44:1367e70. 9. Yagmurdur H, Cakan T, Bayrak A, Arslan M, Baltaci B, Inan N, et al. The effects of etomidate, thiopental, and propofol in induction on hypoperfusion-reperfusion phenomenon during laparoscopic cholecystectomy. Acta Anaesth Scand 2004;48:772e7. 10. Collard CD, Gelman S. Pathophysiology, clinical manifestations, and prevention of ischemia-reperfusion injury. Anesthesiology 2001;94:1133e8. 11. Stipancic I, Zarkovic N, Servis D, Sabolovic S, Tatzber F, Busic Z. Oxidative stress markers after laparoscopic and open cholecystectomy. J Laparoendosc Adv Surg Tech A 2005;15:347e52. 12. Bentes de Souza AM, Rogers MS, Wang CC, Yuen PM, Ng PS. Comparison of peritoneal oxidative stress during laparoscopy and laparotomy. J Am Assoc Gynecol Laparosc 2003;10:65e74. 13. Sammour T, Mittal A, Loveday BP, Kahokehr A, Phillips AR, Windsor JA, et al. Systematic review of oxidative stress associated with pneumoperitoneum. Br J Surg 2009;96:836e50. 14. Cerny V, Cvachovec K. Gastric tonometry and intramucosal pHdtheoretical principles and clinical application. Physiol Res 2000;49:289e97. 15. Del RD, Stewart AJ, Pellegrini N. A review of recent studies on malondialdehyde as toxic molecule and biological marker of oxidative stress. Nutr Metab Cardiovasc Dis 2005;15:316e28. 16. Yoshioka T, Kawada K, Shimada T, Mori M. Lipid peroxidation in maternal and cord blood and protective mechanism against activated-oxygen toxicity in the blood. Am J Obstet Gynecol 1979;135:372e6. 17. Fiddian-Green RG. Gastric intramucosal pH, tissue oxygenation and acid-base balance. Br J Anaesth 1995;74:591e606. 18. Akbulut G, Polat C, Aktepe F, Yilmaz S, Kahraman A, Serteser M, et al. The oxidative effect of prolonged CO2 pneumoperitoneum on renal tissue of rats. Surg Endosc 2004;18:1384e8. 19. Jakimowicz J, Stultiens G, Smulders F. Laparoscopic insufflation of the abdomen reduces portal venous flow. Surg Endosc 1998;12:129e32. 20. Bandyopadhyay D, Kapadia CR. Large bowel ischemia following laparoscopic inguinal hernioplasty. Surg Endosc 2003;17:520e1. 21. Leduc LJ, Mitchell A. Intestinal ischemia after laparoscopic cholecystectomy. J Soc Laparoendosc Surg 2006;10:236e8. 22. Wassenaar EB, Raymakers JT, Rakic S. Fatal intestinal ischemia after laparoscopic correction of incisional hernia. J Soc Laparoendosc Surg 2007;11: 389e93. 23. Hasson HM, Galanopoulos C, Langerman A. Ischemic necrosis of small bowel following laparoscopic surgery. J Soc Laparoendosc Surg 2004;8:159e63. 24. Nickkholgh A, Barro-Bejarano M, Liang R, Zorn M, Mehrabi A, Gebhard MM, et al. Signs of reperfusion injury following CO2 pneumoperitoneum: an in vivo microscopy study. Surg Endosc 2008;22:122e8. 25. Sare M, Hamamci D, Yilmaz I, Birincioglu M, Mentes BB, Ozmen M, et al. Effects of carbon dioxide pneumoperitoneum on free radical formation in lung and liver tissues. Surg Endosc 2002;16:188e92. 26. Zhang GL, Wen WQ, Xing FQ. Effect of enucleation of hysteromyoma by laparoscopic surgery on protein oxidation and lipid hyperoxidation. Chung Hua I Hsueh Tsa Chih 2005;85:177e80. 27. Windsor MA, Bonham MJ, Rumball M. Splanchnic mucosal ischemia: an unrecognized consequence of routine pneumoperitoneum. Surg Laparosc Endosc 1997;7:480e2. 28. Koivusalo AM, Kellokumpu I, Ristkari S, Lindgren L. Splanchnic and renal deterioration during and after laparoscopic cholecystectomy: a comparison of the carbon dioxide pneumoperitoneum and the abdominal wall lift method. Anesth Analg 1997;85:886e91. 29. Xu GS, Liu HN, Li J, Wu XL, Dai XM, Liu YH. Hepatic injury induced by carbon dioxide pneumoperitoneum in experimental rats. World J Gastroenterol 2009; 15:3060e4. 30. Pross M, Schulz HU, Flechsig A, Manger T, Halangk W, Augustin W, et al. Oxidative stress in lung tissue induced by CO2 pneumoperitoneum in the rat. Surg Endosc 2000;14:1180e4. 31. Khoury W, Schreiber L, Szold A, Klausner JM, Wienbroum AA. Renal oxidative stress following CO2 pneumoperitoneum-like conditions. Surg Endosc 2009;23: 776e82. 32. Kaplan N, Yagmurdur H, Kilinc K, Baltaci B, Tezel S. The protective effects of intravenous anesthetics and verapamil in gut ischemia/reperfusion-induced liver injury. Anesth Analg 2007;105:1371e8. 33. Unsal MA, Guven S, Imamoglu M, Aydin S, Alver A. The effect of CO2 insufflation-desufflation attacks on tissue oxidative stress markers during laparoscopy: a rat model. Fertil Steril 2009;92:363e8. 34. Dorweiler B, Pruefer D, Andrasi TB, Maksan SM. Ischemia-reperfusion injury; pathophysiology and clinical implications. Eur J Trauma Emerg Surg 2007;33: 600e12.
Contents lists available at ScienceDirect
Acta Anaesthesiologica Taiwanica journal homepage: www.e-aat.com
Original Article
Increased oxidative stress and gut ischemia caused by prolonged pneumoperitoneum in patients undergoing robot-assisted laparoscopic radical prostatectomy Chiao-Fen Luo 1, Yung-Fong Tsai 1, 2, 3, Chia-Hung Chang 1, Chun-Te Wu 4, Huang-Ping Yu 1, 2 * 1
Department of Anesthesiology, Chang Gung Memorial Hospital, Taoyuan, Taiwan, R.O.C. College of Medicine, Chang Gung University, Taoyuan, Taiwan, R.O.C. Graduate Institute of Clinical Medical Sciences, Chang Gung University, Taoyuan, Taiwan, R.O.C. 4 Department of Urology, Chang Gung Memorial Hospital, Keelung, Taiwan, R.O.C. 2 3
a r t i c l e i n f o
a b s t r a c t
Article history: Received 2 March 2011 Received in revised form 28 April 2011 Accepted 4 May 2011
Objective: To investigate changes in plasma oxidative stress markers associated with prolonged pneumoperitoneum during robot-assisted laparoscopic radical prostatectomy (RALP). Methods: In all, patients of ASA Physical Status IIeIII who intended to undergo RALP were enrolled in the study. Arterial plasma levels of malondialdehyde (MDA) and intramucosal pH were measured 1 minute before and at 1 hour, 2 hours, 3 hours, and 4 hours after the introduction of pneumoperitoneum at an insufflation pressure of 15 mmHg; likewise, they were again measured every 10 minutes after deflation for 60 minutes, at 2 hours and 12 hours after deflation. Results: The mean duration of pneumoperitoneum was around 4 hours. After induction of pneumoperitoneum, the MDA concentrations were significantly elevated at various time points as compared with the preinsufflation value. Significant increase of MDA value was noted also 30 minutes after deflation as compared with the pre-deflation levels. The intramucosal pH value decreased significantly after CO2 insufflation compared with the preinsufflation values. It also increased significantly 2 hours after CO2 deflation as compared with the pre-deflation values. Conclusion: A prolonged pneumoperitoneum in RALP results in decreased splanchnic blood flow. Pneumoperitoneum itself produces oxidative stress, and ischemia-reperfusion model after deflation of pneumoperitoneum produces more oxidative stress. Copyright Ó 2011, Taiwan Society of Anesthesiologists. Published by Elsevier Taiwan LLC. All rights reserved.
Key words: gastric mucosa; hydrogen-ion concentration; malondialdehyde; pneumoperitoneum, artificial; reperfusion injury
1. Introduction Minimally invasive surgery has seen tremendous growth. In 2000, Binder and Kramer1 performed the first robot-assisted laparoscopic radical prostatectomy (RALP), which is a promising minimally invasive surgical approach with possible reduced blood loss, fewer blood product transfusions, shorter care in postanesthesia unit, and shorter hospital stay.2,3 Although laparoscopic surgery is generally considered safe, increased intra-abdominal pressure associated with pneumoperitoneum during laparoscopic procedures greatly impairs the splanchnic perfusion as a result of compression. The detrimental effects of increased intra-abdominal pressure on the hepatic arterial, mesenteric, and intestinal mucosal * Corresponding author. Department of Anesthesiology, Chang Gung Memorial Hospital, No. 5, Fu-Shin Street, Kwei-Shan, Taoyuan 333, Taiwan, R.O.C. E-mail: [email protected] (H.-P. Yu).
blood flows have been described in several studies.4,5 An ischemiareperfusion human model has been observed during and soon after laparoscopic surgery.6e9 After deflation of pneumoperitoneum, intra-abdominal pressure and splanchnic blood flow normalize, thereby representing the reperfusion phase. Clinical manifestations of ischemia-reperfusion injuries are diverse and may include myocardial hibernation/stunning, reperfusion arrhythmias, impaired cerebral function, breakdown of the gastrointestinal barrier, systemic inflammatory response syndrome, and multiorgan dysfunction syndrome.10 Previous studies have documented the impact of CO2 pneumoperitoneum on oxidative stress during laparoscopic cholecystectomies and minor gynecological surgeries.11,12 The duration of the pneumoperitoneum involved in these previous studies was roughly 1 hour. The severity of pneumoperitoneum-induced oxidative stress is suggested to be time dependent.13 However, data for long-term pneumoperitoneums are very limited.
1875-4597/$ e see front matter Copyright Ó 2011, Taiwan Society of Anesthesiologists. Published by Elsevier Taiwan LLC. All rights reserved. doi:10.1016/j.aat.2011.05.010
Prolonged pneumoperitonium-induced increased oxidative stress and gut ischemia
Gastric intramucosal pH (pHi) reflects splanchnic perfusion and oxygenation.14 Its obtainment is minimally invasive, and its measurement is effective for assessing tissue oxygenation adequacy.14 Reactive oxygen species, which damage cellular components and initiate the lipid peroxidation process, are responsible for ischemia-reperfusion injuries.6 Harmful oxidative reactions may occur in organisms so that they are removed by means of enzymatic and nonenzymatic antioxidative mechanisms.11 Malondialdehyde (MDA) is regarded to be the most reliable and producible markers of oxidative stress in the clinical setting.13 The main source of MDA is the peroxidation of polyunsaturated fatty acids with two or more methylene-interrupted double bonds.15 It is referred to as potentially mutagenic and atherogenic because of its interaction with DNA and proteins.15 The aim of the current study was to evaluate the alterations in oxidative stress and splanchnic perfusion during prolonged pneumoperitoneum in RALP. A prospective clinical study was designed, and plasma levels of MDA-lipid peroxidation marker and gastric pHi were measured. 2. Methods 2.1. Patients The study protocol was approved by the ethics committee of Chang Gung Memorial Hospital (IRB 98-2998B, Taoyuan, Taiwan). All patients provided written informed consent. Twelve adult patients whose physical statuses were graded as ASA Status II or III were recruited. The RALP was carried out by a single surgeon. Exclusion criteria included a history of sepsis or shock, cardiopulmonary disease clinically, tobacco smoking, or recent antioxidant or vasoconstrictor use. 2.2. Study protocol General anesthesia was induced intravenously with fentanyl (3 mg/kg), midazolam (0.2e0.3 mg/kg), and rocuronium (0.5e 0.6 mg/kg). A 20-gauge arterial catheter was inserted into the left brachial artery after the induction of anesthesia for blood sampling and arterial blood pressure monitoring. After tracheal intubation, anesthesia was maintained with isoflurane in oxygen at 1e1.5 end-tidal concentration, and the arterial blood pressure was kept within 20% of its preinduction value. The lungs were mechanically ventilated with pressure-controlled ventilation to maintain the end-tidal CO2 at 30e40 mmHg. Bolus dose of rocuronium (0.2 mg/kg) was given every 30 minutes during surgery. Intraoperative electrocardiogram, pulse oximetry, central venous pressure, and arterial blood pressure were constantly monitored. After skin closure, patients were extubated in the operating room. Pneumoperitoneum was created by intraperitoneal insufflation of CO2 with the patient in the supine position. Patients were then placed in the steep Trendelenburg position (30 from horizontal). Intraperitoneal pressure was maintained at 15 mmHg during the induced pneumoperitoneum. 2.3. Measurement Blood samples containing sodium heparin as anticoagulant were obtained for MDA measurements. Baseline value was obtained 1 minute before inducing the pneumoperitoneum. After pneumoperitoneum establishment, blood samples were collected 1 hour after and at 1-hour intervals during the procedure. At the end of the surgery, blood samples were obtained 10 minutes after the deflation of CO2 and at 10-minute intervals for 1 hour, and then
47
at 2 hours and 12 hours after the deflation of CO2. Blood samples for MDA analysis were centrifuged (3500 rpm, 10 minutes) and the supernatants were immediately stored at 80 C until the analysis was performed within 1 week. The MDA content was measured by a thiobarbituric acid assay to estimate the lipid peroxidation products. MDA was treated with thiobarbituric acid to form a colored complex. We measured the levels of thiobarbituric acid reactive substances by adopting the method reported by Yoshioka et al16 Briefly, 0.5 mL plasma, 2.5 mL thiobarbituric acid (200 g/L), and 1 mL TBA (6.7 g/L) were mixed together and boiled for 30 minutes. Two milliliters of butanol was added to the tubes, and the colored supernatant was extracted after centrifugation at 3000 rpm. The absorbance of the supernatant was spectrophotometrically measured at 535 nm. The MDA concentration was expressed in micromoles per mg protein (mmol/mg protein). The plasma level of MDA in each sample was analyzed by enzyme-linked immunoabsorbent assay and reported as femtograms per milligram of protein (fg/mg protein). After the induction of anesthesia, a double-lumen tonometric nasogastric tube (Tonometrics Catheter; Datex-Ohmeda, Helsinki, Finland) was inserted to the stomach. The correct position of the tube was confirmed by positive aspiration of gastric juice. To calculate pHi, arterial blood and gastric juice samples were collected 1 minute before the insufflation of CO2, 1 hour after the insufflation of CO2, at 1-hour intervals thereafter during the procedure, 10 minutes after deflation, at 10-minute intervals until 1 hour after deflation, and 2 hours after deflation of CO2. The pHi was estimated indirectly by the PCO2 measured in the stomach lumen and the bicarbonate concentration measured in the arterial blood with the Henderson-Hasselbalch’s equation.17
h
HCO 3
i
pHi ¼ 6:1 þ log PCO2 0:031 2.4. Statistical analysis All data are presented as mean standard deviation. Calculation and data analysis were performed using SPSS version 17.0 (SPSS Inc., Troy, NY, USA). The levels of MDA and pHi were analyzed and compared using the Wilcoxon signed-rank test. Differences were considered to be statistically significant if p < 0.05. 3. Results Twelve patients with prostate cancer, who underwent RALP performed by a sole surgeon, were enrolled for the study. Demographic and clinical data are presented in Table 1. Data of blood pressure and heart rate during and after the surgery are presented in Table 2. 3.1. Malondialdehyde After CO2 insufflation, the plasma concentration of MDA, as a measure of free radical production, increased significantly as Table 1 Patient demographic characteristics. Variables
Mean standard deviation (n ¼ 12)
Age (y) Height (cm) Weight (kg) Body mass index (kg/m2) Duration of pneumoperitoneum (min)
61.9 8.6 165.3 6.4 73.4 10.7 26.8 3.5 287.2 38.8
48
C.-F. Luo et al
Table 2 Data of mean arterial pressure and heart rate during and after the surgery. Mean arterial pressure was kept within 20% of its preinduction value.
Mean arterial pressure (mmHg) Heart rate (beat/min)
Preinduction
Preinsufflation
þ1h
þ2h
þ3h
þ4h
96.0 16.6 72.3 9.8
78.3 14.6 65.1 16.1
88.4 6.9 64.5 9.7
86.3 5.0 67.8 13.7
86.3 7.3 70.2 15.7
83.4 9.1 70.5 15.4
Deflation
þ 10 min
þ 30 min
þ1h
þ2h
þ 12 h
Mean arterial pressure (mmHg) Heart rate (beat/min)
79.2 10.4 68.2 15.5
92.1 15.1 77.9 10.3
81.2 15.1 81.2 15.1
82.0 12.2 82.0 8.5
94.5 16.0 78.6 12.8
Data shown as the mean standard deviation.
In the present study, significant increase in MDA concentration and decrease in pHi value were observed after the induction of pneumoperitoneum. After deflation, an unexpected increase in MDA value was noted. A prolonged pneumoperitoneum of 4 hours could lead to decreased splanchnic blood flow and increased oxidative stress, not only during the pneumoperutineum but also after the deflation. Numerous outcome measures for oxidative stress can be used clinically, including endogenous antioxidant levels, peroxidation markers, derived gastric pHi, cytokine levels, and histological findings.13 Measurements of lipid peroxidation markers, especially MDA, are generally regarded to be most reliable and reproducible in
the clinical setting.13,15 The present data revealed that the maintenance of intra-abdominal CO2 pressure at 15 mmHg for 4 hours could induce a significant increase in oxidative stress markers. There were two trends in regard to MDA changes throughout the surgery. One occurred during the pneumoperitoneum, and the other appeared after CO2 deflation. During the induced CO2 pneumoperitoneum, the plasma MDA level was significantly higher than its preinsufflation level. It peaked during the second hour and revealed a slight but insignificant decrease in the third and fourth hours. Previous studies suggested that the levels of oxidative stress markers associated with pneumoperitoneums could rise in a timedependent manner.13,18 The CO2 insufflation pressure in our study was constant throughout the surgery, but the MDA level did not continuously increase during the third and fourth hours. The MDA level appeared to achieve homeostasis after being subject to pneumoperitoneum for 2 hours. No other study has evaluated oxidative stress markers during such a long pneumoperitoneum duration. To the best of our knowledge, there are no studies in this regard in prolonged pneumoperitoneum (i.e. 3 hours or 4 hours). In our speculation, there might be some substances that were produced to resist the lipid peroxidation process as time went by. After CO2 deflation, MDA values increased steadily and reached a peak 30 minutes after deflation, which was significantly higher than that during CO2 insufflation. Various studies have investigated the ischemia-reperfusion injury that occurs as a result of pneumoperitoneum.6,7,11,12 Pneumoperitoneum for laparoscopic surgery at intra-abdominal pressure of 12e15 mmHg is much higher than the normal pressure of the portal system (7e10 mmHg). Previous experimental and human studies have shown that CO2 pneumoperitoneum impairs splanchnic perfusion by compressing vessels.5 Portal venous flow is also reduced during laparoscopic procedures,19 and there have been several reports about intestinal ischemia after
Fig. 1. Plasma MDA level in patients undergoing robot-assisted laparoscopic radical prostatectomy. Data are expressed as the mean standard deviation. Difference from preinsufflation value: *p < 0.05, **p < 0.01. Difference from pre-deflation value (þ4 hours after pneumoperitoneum): #p < 0.05. MDA ¼ malondialdehyde.
Fig. 2. pHi value in patients undergoing robot-assisted laparoscopic radical prostatectomy. Data are expressed as the mean standard deviation. Difference from preinsufflation value: *p < 0.05. Difference from pre-deflation value (þ4 hours after pneumoperitoneum): **p < 0.05. pHi ¼ intramucosal pH.
compared with the preinsuffltion value (Fig. 1). The mean peak value appeared 2 hours after CO2 insufflation (95.3 74.9 mmol/ mg), which was significantly higher than the mean baseline value (47.7 14.2 mmol/mg). After the deflation of CO2, MDA values demonstrated a slight but insignificant increase. The significant increase appeared 30 minutes after deflation (106.7 75.0 mmol/ mg) as compared with the pre-deflation levels (75.3 42.9 mmol/ mg). The MDA values nearly returned to baseline levels some 12 hours after CO2 deflation (Fig. 1). 3.2. Intramucosal pH The pHi values significantly decreased after CO2 insufflation as compared with the preinsufflation values. After deflation, the pHi values were still significantly lower than the preinsufflation values. Two hours after CO2 deflation, the pHi value increased and significantly differed as compared with the pre-deflation value (Fig. 2). 4. Discussion
Prolonged pneumoperitonium-induced increased oxidative stress and gut ischemia
laparoscopic procedures.20e23 These findings suggest that pneumoperitoneum for laparoscopic surgery, which consequentially raises the intra-abdominal pressure, may produce significant organ ischemia followed by reperfusion injury on deflation of the abdomen.24,25 Consistent with these findings, our results suggest that an ischemia-reperfusion injury would be present at the end of a prolonged induced pneumoperitoneum. A previous study in women who underwent laparoscopic enucleation of uterine myoma demonstrated increased levels of MDA immediately after surgery, which normalized 24 hours after surgery.26 In our study, plasma MDA levels normalized 12 hours after CO2 deflation. Fall of gastric pHi is an early indicator of inadequate splanchnic perfusion.13,17 It is based on the measurement of increased tissue CO2 production that accompanies anaerobic metabolism in the gut. The pHi is an estimate of the gastric mucosal CO2 and bicarbonate concentration in arterial blood. The pHi value was significantly decreased after CO2 insufflation in our study. Previous studies have reported a measurable and continuous reduction in gastric mucosal pH during laparoscopic cholecystectomy.27,28 These results indicate that splanchnic ischemia occurs during the induced pneumoperitoneum. In our study, the decrease in pHi persisted up to 1 hour after CO2 deflation. Koivusalo et al28 reported a decrease in pHi after the creation of a pnemoperitoneum for laparoscopic cholecystectomy, and this decrease persisted for up to 3 hours after CO2 deflation. Persistent decrease of pHi indicates that although the splanchnic blood flow increases after deflation, however, impaired splanchnic circulation persists even after the termination of the pneumoperitoneum. Decreased splanchnic blood flow and increased oxidative stress were observed during the existing pneumoperitoneum and after its deflation. The clinical relevance of oxidative stress after pneumoperitoneum is related to hepatic injury,29 lung injury,30 and renal injury.31 Light microscopy has also revealed histopathological findings concerning ischemia-reperfusion injuries in the liver and ileum.32,33 It is reported that hypoperfusion-reperfusion injury would initiate a wide and complex array of inflammatory responses that may aggravate local injury and induce impairment of remote organ function as well.34 Given the increasing complexity and duration of laparoscopic procedures, organ ischemia-reperfusion injury and oxidative stress associated with prolonged pneumoperitoneum may become more pervasive. In conclusion, a prolonged pneumoperitoneum of 4 hours results in decreased splanchnic blood flow and increased oxidative stress both during the pneumoperitoneum and after deflation. Although RALP is a promising and minimally invasive surgical approach with many advantages, the oxidative stress generated during a prolonged pneumoperitoneum should be noted. The clinical significance of prolonged pneumoperitoneum-associated oxidative stress and the impact of its reduction on defined clinical endpoints need further investigation. Acknowledgment This study was supported by Chang Gung Medical Grant (CMRPG390881). References 1. Binder J, Kramer W. Robotically-assisted laparoscopic radical prostatectomy. BJU Int 2001;87:408e10. 2. Coelho RF, Chauhan S, Palmer KJ, Rocco B, Patel MB, Patel VR. Robotic-assisted radical prostatectomy: a review of current outcomes. BJU Int 2009;104:1428e35. 3. Ficarra V, Cavalleri S, Novara G, Aragona M, Artibani W. Evidence from robotassisted laparoscopic radical prostatectomy: a systematic review. Eur Urol 2007;51:45e55. 4. Diebel LN, Wilson RF, Dulchavsky SA, Saxe J. Effect of increased intraabdominal pressure on hepatic arterial, portal venous, and hepatic microcirculatory blood flow. J Trauma 1992;33:279e82.
49 5. Eleftheriadis E, Kotzampassi K, Botsios D, Tzartinoglou E, Farmakis H, Dadoukis J. Splanchnic ischemia during laparoscopic cholecystectomy. Surg Endosc 1996;10:324e6. 6. Glantzounis GK, Tselepis AD, Tambaki AP, Trikalinos TA, Manataki AD, Galaris DA, et al. Laparoscopic surgery-induced changes in oxidative stress markers in human plasma. Surg Endosc 2001;15:1315e9. 7. Glantzounis GK, Tsimaris I, Tselepis AD, Thomas C, Galaris DA, Tsimoyiannis EC. Alterations in plasma oxidative stress markers after laparoscopic operations of the upper and lower abdomen. Angiology 2005;56:459e65. 8. Baysal Z, Togrul T, Aksoy N, Cengiz M, Celik H, Boleken ME, et al. Evaluation of total oxidative and antioxidative status in pediatric patients undergoing laparoscopic surgery. J Pediatr Surg 2009;44:1367e70. 9. Yagmurdur H, Cakan T, Bayrak A, Arslan M, Baltaci B, Inan N, et al. The effects of etomidate, thiopental, and propofol in induction on hypoperfusion-reperfusion phenomenon during laparoscopic cholecystectomy. Acta Anaesth Scand 2004;48:772e7. 10. Collard CD, Gelman S. Pathophysiology, clinical manifestations, and prevention of ischemia-reperfusion injury. Anesthesiology 2001;94:1133e8. 11. Stipancic I, Zarkovic N, Servis D, Sabolovic S, Tatzber F, Busic Z. Oxidative stress markers after laparoscopic and open cholecystectomy. J Laparoendosc Adv Surg Tech A 2005;15:347e52. 12. Bentes de Souza AM, Rogers MS, Wang CC, Yuen PM, Ng PS. Comparison of peritoneal oxidative stress during laparoscopy and laparotomy. J Am Assoc Gynecol Laparosc 2003;10:65e74. 13. Sammour T, Mittal A, Loveday BP, Kahokehr A, Phillips AR, Windsor JA, et al. Systematic review of oxidative stress associated with pneumoperitoneum. Br J Surg 2009;96:836e50. 14. Cerny V, Cvachovec K. Gastric tonometry and intramucosal pHdtheoretical principles and clinical application. 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Leduc LJ, Mitchell A. Intestinal ischemia after laparoscopic cholecystectomy. J Soc Laparoendosc Surg 2006;10:236e8. 22. Wassenaar EB, Raymakers JT, Rakic S. Fatal intestinal ischemia after laparoscopic correction of incisional hernia. J Soc Laparoendosc Surg 2007;11: 389e93. 23. Hasson HM, Galanopoulos C, Langerman A. Ischemic necrosis of small bowel following laparoscopic surgery. J Soc Laparoendosc Surg 2004;8:159e63. 24. Nickkholgh A, Barro-Bejarano M, Liang R, Zorn M, Mehrabi A, Gebhard MM, et al. Signs of reperfusion injury following CO2 pneumoperitoneum: an in vivo microscopy study. Surg Endosc 2008;22:122e8. 25. Sare M, Hamamci D, Yilmaz I, Birincioglu M, Mentes BB, Ozmen M, et al. Effects of carbon dioxide pneumoperitoneum on free radical formation in lung and liver tissues. Surg Endosc 2002;16:188e92. 26. Zhang GL, Wen WQ, Xing FQ. Effect of enucleation of hysteromyoma by laparoscopic surgery on protein oxidation and lipid hyperoxidation. Chung Hua I Hsueh Tsa Chih 2005;85:177e80. 27. Windsor MA, Bonham MJ, Rumball M. Splanchnic mucosal ischemia: an unrecognized consequence of routine pneumoperitoneum. Surg Laparosc Endosc 1997;7:480e2. 28. Koivusalo AM, Kellokumpu I, Ristkari S, Lindgren L. Splanchnic and renal deterioration during and after laparoscopic cholecystectomy: a comparison of the carbon dioxide pneumoperitoneum and the abdominal wall lift method. Anesth Analg 1997;85:886e91. 29. Xu GS, Liu HN, Li J, Wu XL, Dai XM, Liu YH. Hepatic injury induced by carbon dioxide pneumoperitoneum in experimental rats. World J Gastroenterol 2009; 15:3060e4. 30. Pross M, Schulz HU, Flechsig A, Manger T, Halangk W, Augustin W, et al. Oxidative stress in lung tissue induced by CO2 pneumoperitoneum in the rat. Surg Endosc 2000;14:1180e4. 31. Khoury W, Schreiber L, Szold A, Klausner JM, Wienbroum AA. Renal oxidative stress following CO2 pneumoperitoneum-like conditions. Surg Endosc 2009;23: 776e82. 32. Kaplan N, Yagmurdur H, Kilinc K, Baltaci B, Tezel S. The protective effects of intravenous anesthetics and verapamil in gut ischemia/reperfusion-induced liver injury. Anesth Analg 2007;105:1371e8. 33. Unsal MA, Guven S, Imamoglu M, Aydin S, Alver A. The effect of CO2 insufflation-desufflation attacks on tissue oxidative stress markers during laparoscopy: a rat model. Fertil Steril 2009;92:363e8. 34. Dorweiler B, Pruefer D, Andrasi TB, Maksan SM. Ischemia-reperfusion injury; pathophysiology and clinical implications. Eur J Trauma Emerg Surg 2007;33: 600e12.