UJ 35 Summer.pdf 553Vol. 9 | No. 3 | Summer 2012 |U R O LO G Y J O U R N A L Urology and Nephrology Research Center, Shohada- e-Tajrish Medical Center, Shahid Beheshti University of Medical Sciences, Teh- ran, Iran Hossein Karami, Alireza Rezaei, Mohammad Mohsen Mazloomfard, Babak Javanmard, Behzad Lotfi, Amir Haji-Mohammadmehdi-Arbab Effects of Surgical Position on Patients’ Arterial Blood Gases During Percutaneous Nephrolithotomy Corresponding Author: Mohammad Mohsen Mazloomfard, MD Urology and Nephrology Research Center, No.103, 9th Boustan St., Pasdaran Ave., Tehran, Iran Tel: +98 21 2256 7222 Fax: +98 21 2277 0954 E-mail: mazloomfard@ yahoo.com Received August 2010 Accepted January 2012 ENDOUROLOGY AND STONE DISEASE Purpose: - Materials and Methods: - - repositioning. Results : and supine positions, respectively (P 2 P = .21). Arterial oxygen pressure (PaO2 P = .01) and P P 2 3 prone, and supine groups. Conclusion: Keywords: percutaneous nephrolithotomy, blood gas analysis, prone position 554 | Endourology and Stone Disease INTRODUCTION pulmonary ventilation and perfusion. Atelectasis of the dependent areas of the lung due to general arterial oxygen tension.(1) - tion and ventilation. Patients undergoing surgery in prone - space to tidal volume ratio.(2) This position has been report- - tory distress syndrome.(3) Alternating the positions could also improve arterial oxygen pressure in these patients.(4) an improvement in both oxygenation and carbon dioxide - tion.(5) (ABG) changes after repositioning patients to prone, su- - MATERIALS AND METHODS groups using pseudorandomization method (30 patients in - supine positions, respectively. - anomalies, uncontrolled coagulopathies, previous history of or respiratory disease, and children younger than 15 years - - ing to their groups. All the patients received balanced anes- - - Throughout the study, the ventilator settings (tidal volume, 2 - and 20 minutes after repositioning using ABL 330® blood - Demographic characteristics, operation duration, hemo- - P values RESULTS - spectively (P 2 supine positions, respectively (P = .21). Demographic and P = .56). respectively (P P and complications, such as sepsis in the three groups. 555Vol. 9 | No. 3 | Summer 2012 |U R O LO G Y J O U R N A L Effects of Surgical Positions on Patients’ ABG During PCNL | Karami et al Table 2 summarizes the ABG analyses data of patients in the three groups. After positioning, PaO2 - P = P < P = .23). The changes of PaO2 - icantly different from that in supine group (P =.035). With 2 P P = .2), P = .3). 3 from each other. DISCUSSION Percutaneous nephrolithotomy can be carried out in differ- ent positions; the three common positions are prone, lateral, and supine. We demonstrated that oxygenation improves Alterations in distribution of pulmonary ventilation and studies.(6,7) The combined effect of position and general an- - of oxygenation and carbon dioxide elimination. Mentzelo- mechanically ventilated chronic obstructed pulmonary dis- ease, repositioning to prone could facilitate oxygenation recumbent position. have found that in anesthetized and paralyzed obese sub- jects, the prone position improves pulmonary function and increases functional residual capacity, lung compliance, and oxygenation.(7) - the prone position does not change oxygen consumption; author concluded that changes in alveolar ventilation could possibly be the result of circulatory changes caused by the prone position.(9) Papazian and colleagues have indicated that the prone position increases oxygenation and reduces syndrome.(10) that the prone position increases the homogeneity of the ventilation perfusion distribution.(11) ventilation-perfusion matching.(12,13) mechanically ventilated patients, regional ventilation-per- the prone position. Prone position diminishes the percent- age of the lung volume in the dependent zones and as a result, the volume of potentially collapsible lung. During mechanical ventilation, the tidal volume is preferen- tially distributed to the nondependent areas of the lung that have a proportionately larger volume in the prone position positioning in both pulmonary alveolar proteinosis patients and the healthy controls.(14) Soro and colleagues found that in the prone position and PaO2 2 patients undergoing surgery in prone position under general the tidal volume.(2) The effect of lateral position on arterial oxygenation un- der anesthesia is still under debate. Kerbl and colleagues compression of the patients.(15) Gofrit and associates rec- to avoid severe hypoxemia and hypercarbia.(16) Although - 556 | - elimination.(5) 2. We demonstrated that PaO2 increases after repositioning - 2. We also found that 2 3 supine positions in this percutaneous procedure. history of cardiovascular or respiratory disease, abnormal - - - tion. CONCLUSION - - and ventilation, serial arterial blood gases analyses during longer operations could be helpful. CONFLICT OF INTEREST None declared. Endourology and Stone Disease 4. Kim MJ, Hwang HJ, Song HH. A randomized trial on the effects of body positions on lung function with acute res- piratory failure patients. Int J Nurs Stud. 2002;39:549-55. 5. Manikandan S, Rao G. Effect Of Surgical Position On Pul- monary Gas Exchange In Neurosurgical Patients. Indian J Anaesth. 2002;46:356-9. 6. Lumb AB, Nunn JF. Respiratory function and ribcage con- tribution to ventilation in body positions commonly used during anesthesia. Anesth Analg. 1991;73:422-6. 7. Pelosi P, Croci M, Calappi E, et al. Prone positioning improves pulmonary function in obese patients during general anesthesia. Anesth Analg. 1996;83:578-83. 8. 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