articles
nature publishing group
Intervention and Prevention
Update on Best Practice Recommendations for Anesthetic Perioperative Care and Pain Management in Weight Loss Surgery, 2004–2007 Roman Schumann1, Stephanie B. Jones2, Bronwyn Cooper3, Scott D. Kelley4, Mark Vanden Bosch5, Vilma E. Ortiz6, Kathleen A. Connor7, Michael D. Kaufman8, Alan M. Harvey4 and Daniel B. Carr1 To reevaluate and update evidence-based best practice recommendations published in 2004 for anesthetic perioperative care and pain management in weight loss surgery (WLS), we performed a systematic search of English-language literature on anesthetic perioperative care and pain management in WLS published between April 2004 and May 2007 in MEDLINE and the Cochrane Library. We identified relevant abstracts by using key words, retrieved full text articles, and stratified the resulting evidence according to systems used in established evidence-based models. We updated prior evidence-based best practice recommendations based upon interim literature. In instances of controversial or inadequate scientific evidence, the task force reached consensus recommendations following evaluation of the best available information and expert opinion. The search yielded 1,788 abstracts, with 162 potentially relevant titles; 45 were reviewed in detail. Despite more information on perioperative management of patients with obstructive sleep apnea (OSA), evidence to support preoperative testing and treatment or to guide perioperative monitoring is scarce. New evidence on appropriate intraoperative dosing of muscle relaxants allows for greater precision in their use during WLS. A novel application of α-2 agonists for perioperative anesthetic care is emerging. Key elements that may enhance patient safety include integration of the latest evidence on WLS, obesity, and collaborative multidisciplinary care into clinical care. However, large gaps remain in the evidence base. Obesity (2009) 17, 889–894. doi:10.1038/oby.2008.569
Introduction
Evidence-based best practice recommendations for anesthetic perioperative care and pain management in weight loss surgery (WLS) were prepared in 2004 and published the following year (1,2). These recommendations focused on patient safety and addressed pre-, intra-, and postoperative anesthesia patient care, including pain management (1). The present report updates key aspects of anesthetic perioperative practice to improve patient safety. It provides suggestions for medical error reduction and systems improvements, credentialing, and future research. This update is an extension of, and builds upon, our prior recommendations (1), all of which continue to be endorsed and disseminated by this task force. For this
reason, earlier recommendations are restated only if we identified confirmatory new evidence. Relevant recent advances include the development of practice guidelines for perioperative management of patients with obstructive sleep apnea (OSA) (3). Clinical evidence to refine dosing recommendations for several neuromuscular blocking agents in severely obese patients has emerged (4–6), and α-2 agonists, a well-known drug class, are being applied in innovative contexts that include perioperative anesthetic care for WLS patients (7–9). Multimodal postoperative pain management strategies have been effectively used after WLS (10–12). New target areas for outcomes research include the effects of rigorous intra- and postoperative glycemic control as
1 Department of Anesthesia, Tufts-New England Medical Center, Boston, Massachusetts, USA; 2Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA; 3Department of Anesthesiology, University of Massachusetts Memorial Medical Center, Worcester, Massachusetts, USA; 4Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women’s Hospital, Boston, Massachusetts, USA; 5Department of Anesthesiology, Berkshire Health Systems, Pittsfield, Massachusetts, USA; 6Department of Anesthesia and Critical Care, Massachusetts General Hospital, Boston, Massachusetts, USA; 7Department of Anesthesiology, Newton-Wellesley Hospital, Newton, Massachusetts, USA; 8Department of Anesthesiology, The Lahey Clinic, Burlington, Massachusetts, USA. Correspondence: Roman Schumann (
[email protected])
Received 22 June 2007; accepted 25 September 2007; published online 19 February 2009. doi:10.1038/oby.2008.569
obesity | VOLUME 17 NUMBER 5 | MAY 2009
889
articles Intervention and Prevention well as the possible benefits of various perioperative monitoring techniques and protocols. Methods and Procedures The task group reconvened with prior participants as well as several new members; all have expertise and interest in WLS and practice either in academic institutions or private hospitals that perform a high volume of WLS (50 to >400 cases during the year prior to this report). The group reached consensus to stratify the available relevant evidence. It assessed relevant clinical research articles from peer-reviewed journals for results with a direct or potential impact on patient safety in WLS, and adopted a best available evidence approach as needed to develop recommendations. Many areas of anesthesia care related to WLS lack sufficient numbers of adequately controlled studies to permit aggregate analyses of data using statistical techniques such as meta-analysis. Consequently, we adopted the best available evidence approach using case reports and other descriptive studies. This literature allowed the task group to discern common clinical practice patterns. We graded evidence from cited literature. In this context, the evidence grading referred to the nature of the retrieved studies insofar as they addressed their original outcomes (e.g., arterial oxygen saturation or analgesic consumption) rather than specific safety outcomes of primary concern to the task group. Grading of recommendations by the task group reflects its qualitative assessment of the strength and consistency of the available literature, along with its generalizability to safety outcomes. All the available information served as the basis for consensus recommendations. We searched PubMed, MEDLINE, and the Cochrane Library for articles on WLS and anesthesia, anesthetic agents, pain management, intra- and postoperative management, perioperative care, OSA, and risk factors published between April 2004 and May 2007. The system used to grade the quality of the evidence has been described previously (1). The literature search yielded 1,788 abstracts, with 162 potentially relevant titles. Following full text evaluation of the latter, 45 articles were reviewed and extracted in detail. These included randomized controlled trials, prospective and retrospective cohort studies, metaanalyses, case reports, prior systematic reviews, expert opinion, and guidelines. The focus of the analytical process mirrored that employed previously (1). Results Preoperative evaluation and preparation
The literature suggests that OSA, also termed sleep-disordered breathing, is underdiagnosed in WLS patients. Mandatory polysomnography (PSG) has been proposed (13,14), but it is not part of the practice guidelines for perioperative management of patients with OSA (3), and it is unclear whether this approach would actually improve outcomes. In addition to a high index of suspicion during the preoperative anesthesia evaluation, simple measurements (15) may indicate the presence of OSA and facilitate decision making for PSG referral. Continuous postive airway pressure (CPAP) treatment is able to reduce or reverse cardiovascular structural changes induced by severe OSA (3,16–18). Patients with OSA who have been treated preoperatively have fewer perioperative complications than those who have not (19,20). However, the duration of preoperative OSA treatment necessary to decrease perioperative risk is undetermined. Data consistent with that on the general surgical population confirm that smoking is risk factor for adverse postoperative outcomes in WLS, as is increasing BMI (21). 890
Recommendations
• PSG in selected patients; when in doubt, clinical preoperative assessment that includes gender, waist-to-hip ratio, and neck circumference (categories B and D). • Strong consideration of a preoperative CPAP treatment period for patients with a PSG diagnosis of moderate to severe OSA (category C). • Smoking cessation at least 6 weeks prior to surgery (category C), with active support from the WLS program to help patients achieve and sustain compliance (categories C and D). Intraoperative management
Induction and emergence. Increasing the time available to manage potentially difficult airways adds a safety margin during induction of anesthesia, particularly in those undergoing WLS. The ability of severely obese patients to tolerate apnea during induction of general anesthesia is prolonged by preoxygenation in the sitting position, which is more efficacious than preoxygenation in the supine position (22). As in prior studies, this finding supports a position other than supine (e.g., sitting or >30° reversed Trendelenburg) to promote oxygenation during critical phases of anesthesia in WLS patients. Use of a CPAP device to maintain positive end expiratory pressure (PEEP) of 10 cm H2O for 5 min during anesthesia induction also prolongs nonhypoxic apnea (23). However, there have been no trials of more feasible and clinically practical applications. Intubating laryngeal mask airway devices, with and without indirect visual display, offer (after a training period) airway management as rapid and effective as standard direct laryngoscopy in obese patients. The devices offer alternatives to direct laryngoscopy for tracheal intubation by providing a different mechanical approach to securing the airway (24,25). Such devices may also improve success when attempting ventilation prior to securing the airway. A study on closed claims related to difficult airway management showed obesity as a factor in 37% of claims related to induction of anesthesia and 67% of extubation claims. In 28% of extubation claims, a diagnosis of OSA was present (26). The majority of extubation or recovery claims were associated with difficult intubation on induction, obesity, and/or OSA. A recruitment maneuver (27) can provide short-lived improvement of oxygenation prior to extubation in severely obese patients, but the technique has not yet been assessed for potential improvement of outcomes. Recommendations
• Routine use of >30° reverse Trendelenburg position during induction of, and emergence from, anesthesia (categories A and D). • Consideration of CPAP of ~10 cm H2O during preoxygenation to prolong nonhypoxic apnea (category A). • Inclusion of intubating laryngeal mask airway devices as part of alternative airway management devices immediately available in the operating room (categories A and B). VOLUME 17 NUMBER 5 | MAY 2009 | www.obesityjournal.org
articles Intervention and Prevention Maintenance of anesthesia. Although there are measurable differences in recovery profiles after use of different general anesthetic techniques or agents, including nitrous oxide, they do not result in clinically relevant outcome improvements for patients undergoing open or laparoscopic WLS (28–34). Several studies have either evaluated or included intraoperative processed electroencephalography titration of general anesthesia during WLS (31,32,35–39), but none determined its effect on safety outcomes. Very severe obesity (>50) may be a risk factor for increased surgical complications from WLS (38). However, anesthetic outcomes after similar anesthetic management strategies do not differ between very severely obese patients and their less severely obese counterparts (38,40). Clonidine and dexmedetomidine are α-2 agonists, a wellknown drug class, shown to be a potent adjunct to anesthetics. Preoperative oral clonidine in obese patients with OSA reduces anesthetic as well as intra- and postoperative opioid requirements (9). Intraoperative intravenous dexmedetomidine in open WLS has a similar anesthetic and opioid-sparing effect (7), and allowed the successful opioid-free anesthetic management of a severely obese patient undergoing WLS (8). However, at the time of this article’s preparation, dexmedetomidine had not received Food and Drug Administration approval for intraoperative use. Further studies on safety and optimal perioperative dosing (including timing) are needed. Recommendation
• Consideration of preoperative oral clonidine unless medically or surgically contraindicated (categories A and C). Intraoperative oxygenation. Several methods to improve intraoperative oxygenation during WLS have been evaluated. Vital capacity or recruitment maneuvers, in addition to PEEP during open WLS, increase oxygenation (41,42). PEEP of ~15 cm H2O effectively maintains functional residual capacity and improves oxygenation during laparoscopic WLS (27). However, these treatments may require increased fluid administration or the use of vasopressors for hemodynamic stability (27,42). Recommendation
• Initial treatment of intraoperative hypoxemia with recruitment maneuvers and PEEP (15 cm H2O) while monitoring their potential hemodynamic effects (categories A and B). Other interventions. In laparoscopic WLS, postoperative nausea and vomiting is more common in patients who receive less intraoperative fluid replacement at a slower rate than those who receive more intraoperative fluid replacement (43). Achievement of perioperative euglycemia is already a standard target for perioperative patient management in general. We did not identify any literature specific to WLS on intra- and postoperative glycemic management and its effects on outcomes. Recommendation
• Maintenance of euvolemia (category C). obesity | VOLUME 17 NUMBER 5 | MAY 2009
Intraoperative drug dosing. Several pharmacodynamic studies in severely obese patients have clarified optimal dosing requirements for different neuromuscular blocking agents (4–6). Dosing of antibiotic prophylaxis according to current guidelines achieves adequate blood levels in most WLS patients, but antibiotic tissue levels are frequently insufficient (44). When using target-controlled infusion anesthesia, an intravenous drug delivery method not yet approved for use in the United States, the propofol dose should be more closely based on total body weight than would be suggested by the Servin dosing formula (36). During remifentanil target-controlled infusion for WLS, acute opioid tolerance can occur (35). Recommendations
• Dosing of cisatracurium and rocuronium according to ideal body weight during standard induction of general anesthesia (category A). • Dosing of succinylcholine at 1 mg/kg total body weight (category A). • For target-controlled infusion (not yet approved in the United States), calculation of propofol dose to more closely reflect total body weight (category C). Postanesthesia care
Early treatment of postoperative hypoxemia with noninvasive positive pressure ventilation support (NIV) in nonobese, non-OSA patients at risk for respiratory failure following elective surgery reduces the incidence of reintubation (45–47), Intensive care unit length of stay, pneumonia, infection, and sepsis (45). NIV use by previously untrained patients is feasible in the presence of a trained respiratory technician (46). These findings may be extrapolated to patients undergoing WLS. A joint decision between the anesthesiologist, surgeon, respiratory technician, and nurse should determine whether NIV is used in selected WLS patients. Awareness of predictors of increased perioperative risk and use of opioid-sparing techniques have enabled laparoscopic gastric bypass and the laparoscopic gastric banding to be performed safely as 23-h stay and outpatient procedures, respectively (48,49). However, these results do not provide conclusive evidence to permit generalization to all WLS patients. Therefore, until further evidence emerges, patients with OSA should not be considered candidates for outpatient WLS (3). Instead, they should be monitored in a PACU or equivalent environment for 3 h beyond the standard observation time of their non-OSA counterparts. They may be discharged from this environment when baseline SpO2 can be maintained on room air, and no hypoxemia/airway obstruction occurs when left undisturbed (3). Recommendations
• Consensus-based (surgeon, anesthesiologist, respiratory therapist, nurse) determination of early postoperative use of NIV support to treat postoperative hypoxemia in selected WLS patients (categories A, B, and C). 891
articles Intervention and Prevention • Adherence to the American Society of Anesthesiologists Practice Guidelines for the Perioperative Management of Patients with OSA (category D).
should also serve as the interdepartmental liaison to weight loss surgeons and be part of the multidisciplinary care team. Recommendations
Postoperative pain management
Recent data on the efficacy and safety of multimodal pain management strategies for WLS patients are consistent with this accepted approach of opioid–sparing postoperative analgesia in the general surgical patient population (50). The nonsteroidal, antiinflammatory, ketorolac, has been successfully used in a variety of dosing regimens to reduce the need for opioid analgesics in open and laparoscopic WLS (10–12). Local anesthetic port or wound infiltration for open surgery is part of an effective multimodal analgesic approach (11,12). The usefulness of α-2 agonists in perioperative analgesia for WLS and other procedures is promising and currently under investigation. The use of thoracic epidural analgesia improves pulmonary function measurements following abdominal surgery in obese patients (51). Epidural solutions for postoperative neuraxial analgesia in patients with OSA should be opioid-free because of increased risk for respiratory depression (3).
• Assignment of a board-certified anesthesiologist advisor with demonstrated clinical experience in the care of severely obese patients (category D). • Use of the anesthesiologist advisor to coordinate intradepartmental education and proctoring to establish proficiency in anesthesia care for WLS patients (category D). • Use of the anesthesiologist advisor as interdepartmental liaison to WLS programs and the extended WLS care team (category D). Medical error reduction and systems improvement
We found no studies that addressed multidisciplinary teamwork and outcomes with respect to WLS. Optimal outcomes require effective and unimpaired intraand perioperative multidisciplinary communication among care givers. Development of perioperative care pathways for patients with OSA is at an early stage, and their further refinement for WLS patients is needed (3).
Recommendations
• Use of opioid-sparing multimodal analgesic strategies, including local anesthetics and nonsteroidal antiinflammatory medications, unless specifically contraindicated (categories A and C). • Opioid-free solutions for thoracic epidural pain management in OSA patients (category C). Credentialing
There is currently no evidence on the impact of credentialing anesthesiologists for WLS on patient safety or outcomes. Expert consensus concludes that proficiency in anesthetic techniques for severely obese patients needs to be part of the skill set and scope of anesthesia providers, and not limited to those focusing upon WLS. Evidence-based best practice recommendations for WLS patients may be applicable and of benefit to severely obese patients presenting for anesthesia and surgery unrelated to WLS. Because of the anesthetic implications of severe obesity and WLS, every WLS program should coordinate with a supporting anesthesia department. The anesthesia department should identify a board-certified anesthesiologist to function as an advisor to the department and the WLS program on perioperative care issues in WLS patients. This anesthesiologist should have demonstrated proficiency in the management of the severely obese patient. Anesthesia departments are encouraged to define the administrative responsibilities for this position within their institutions. Such responsibilities should include education and proctoring of staff to establish proficiency in the care of severely obese WLS patients, as well as development of anesthesia care pathways for WLS patients. The anesthesiologist should coordinate ongoing departmental communication and continuing medical education on anesthesia care for WLS. He or she 892
Future research
Research is needed in the following areas: • The role and parameters of preoperative OSA treatment for perioperative safety outcomes in WLS. • Intra- and perioperative drug dosing, including prophylactic antibiotic tissue pharmacokinetic assessment. • Appropriate use of α-2 agonists in the perioperative care of WLS patients. • Strategies for intra- and postoperative glycemic management. • Impact of advanced anesthetic effect monitoring on outcomes. • Evidence-based postoperative care guidelines for WLS patients with OSA. • Further delineation of optimal anesthetic care for WLS patients with increased BMI (>50), age (>60), and quantity and severity of comorbidities. • Impact of an organized multidisciplinary care team on WLS safety outcomes. • Effect of primary surgical and overall care team pathways to decrease and/or treat perioperative anesthetic and surgical complications in the immediate postoperative period. Discussion
Determining best anesthetic practice for WLS to improve safety and other outcomes is a challenging, long-term enterprise. Progress has been made in the past 3 years for patients affected by sleep-disordered breathing. The American Society of Anesthesiologists OSA practice guidelines are relevant to the assessment of patient appropriateness for outpatient WLS, and guide their postoperative monitoring to some degree (3). However, remaining questions such as how to identify patients who should have a preoperative PSG, whether preoperative VOLUME 17 NUMBER 5 | MAY 2009 | www.obesityjournal.org
articles Intervention and Prevention CPAP treatment of OSA patients would improve postoperative outcomes and help determine clear criteria for appropriate postoperative monitoring of patients with OSA, all persist. Administration of α-2 agonists is capable of extended benefit beyond the operating room, possibly including long-term outcomes, such as reduced mortality from cardiac events (52). Although promising, further study is needed to define the exact role and dosing parameters of this drug class for perioperative patient care in WLS. Opioid-sparing multimodal analgesia has been further validated for WLS patients and should become a standard of care (11,12). Although intraoperative drug dosing for severely obese patients has been determined for several neuromuscular blocking agents, proper dosing for many medications, including antibiotics (44), has not yet been validated in this population. Evidence on the effects of multidisciplinary treatment pathways on patient outcomes for elective WLS and its early postoperative complications is needed but not yet available. Recommendations in this area of care, as well as for the effect of care team communication and anesthesia credentialing for WLS, are still based on expert opinion. No outcomes research related to WLS in adolescent patients is yet available. This update reconfirms prior recommendations (1), and adds new ones based on clinical literature during the past 3 years. Appendix A is a summary of the 2004 and 2007 task force recommendations (Appendix A). This summary represents the task group’s comprehensive consensus recommendations to date. The evidence base to optimize safety and other outcomes is disproportionately small relative to the high prevalence and public health burden of obesity; likewise with consequent WLS and non–weight loss-related surgery in extremely obese patients. The systematic updating of the available evidence should clarify what is already known and prioritize an ever-evolving research agenda. SUPPLEMENTARY MATERIAL To review task group appendices, go to www.mass.gov/dph and search “Weight Loss Surgery.”
Acknowledgments We thank Frank Hu for advice in manuscript preparation, Leslie Kirle for administrative support, and Rita Buckley for research and editorial services. This report on WLS was prepared for the Betsy Lehman Center for Patient Safety and Medical Error Reduction (Commonwealth of Massachusetts Boston, MA). Manuscript preparation was supported, in part, by the Boston Obesity Nutrition Research Center grant P30-DK-46200 and the Center for Healthy Living, Division of Nutrition, Harvard Medical School.
Disclosure Dr Kelley is medical director of Aspect Medical Systems, which manufactures a processed-electroencephalography monitoring system. Use of these types of systems is discussed in this article. © 2009 The Obesity Society
REFERENCES 1. Schumann R, Jones SB, Ortiz VE, et al. Best practice recommendations for anesthetic perioperative care and pain management in weight loss surgery. Obes Res 2005;13:254–266. 2. Lehman Center Weight Loss Surgery Expert Panel. Commonwealth of Massachusetts Betsy Lehman Center for Patient Safety and Medical Error obesity | VOLUME 17 NUMBER 5 | MAY 2009
Reduction Expert Panel on Weight Loss Surgery: executive report. Obes Res 2005;13:205–226. 3. ASA practice guidelines for the perioperative management of patients with obstructive sleep apnea. Anesthesiology 2006;104:1081–1093. 4. Lemmens HJ, Brodsky JB. The dose of succinylcholine in morbid obesity. Anesth Analg 2006;102:438–442. 5. Leykin Y, Pellis T, Lucca M et al. The effects of cisatracurium on morbidly obese women. Anesth Analg 2004;99:1090–1094. 6. Leykin Y, Pellis T, Lucca M et al. The pharmacodynamic effects of rocuronium when dosed according to real body weight or ideal body weight in morbidly obese patients. Anesth Analg 2004;99:1086–1089. 7. Feld JM, Hoffman WE, Stechert MM, Hoffman IW, Ananda RC. Fentanyl or dexmedetomidine combined with desflurane for bariatric surgery. J Clin Anesth 2006;18:24–28. 8. Hofer RE, Sprung J, Sarr MG, Wedel DJ. Anesthesia for a patient with morbid obesity using dexmedetomidine without narcotics. Can J Anesth 2005;52:176–180. 9. Pawlik MT, Hansen E, Waldhauser D, Selig C, Kuehnel TS. Clonidine premedication in patients with sleep apnea syndrome: a randomized, doubleblind, placebo-controlled study. Anesth Analg 2005;101:1374–1380. 10. Govindarajan R, Ghosh B, Sathyamoorthy MK et al. Efficacy of ketorolac in lieu of narcotics in the operative management of laparoscopic surgery for morbid obesity. Surg Obes Relat Dis 2005;1:530–535. 11. Kamelgard JI, Kim KA, Atlas G. Combined preemptive and preventive analgesia in morbidly obese patients undergoing open gastric bypass: a pilot study. Surg Obes Relat Dis 2005;1:12–16. 12. Madan AK, Ternovits CA, Speck KE, Tichansky DS. Inpatient pain medication requirements after laparoscopic gastric bypass. Obes Surg 2005;15:778–781. 13. Hallowell PT, Stellato TA, Schuster M et al. Potentially life-threatening sleep apnea is unrecognized without aggressive evaluation. Am J Surg 2007;193:364–367. 14. O’Keeffe T, Patterson EJ. Evidence supporting routine polysomnography before bariatric surgery. Obes Surg 2004;14:23–26. 15. Sharma SK, Kurian S, Malik V et al. A stepped approach for prediction of obstructive sleep apnea in overtly asymptomatic obese subjects: a hospital based study. Sleep Med 2004;5:351–357. 16. Arias MA, García-Río F, Alonso-Fernández A, Martínez I, Villamor J. Pulmonary hypertension in obstructive sleep apnoea: effects of continuous positive airway pressure: a randomized, controlled cross-over study. Eur Heart J 2006;27:1106–1113. 17. Shivalkar B, Van de Heyning C, Kerremans M et al. Obstructive sleep apnea syndrome: more insights on structural and functional cardiac alterations, and the effects of treatment with continuous positive airway pressure. J Am Coll Cardiol 2006;47:1433–1439. 18. Lattimore JDL, Celemajer DS, Wilcox I. Obstructive sleep apnea and cardiovascular disease. J Am Coll Cardiol 2003;41:1429–1437. 19. Bryson GL, Chung F, Finegan BA et al. Patient selection in ambulatory anesthesia—an evidence-based review: part I. Can J Anesthe 2004;51:768–781. 20. Gupta RM, Parvizi J, Hanssen AD, Gay PC. Postoperative complications in patients with obstructive sleep apnea syndrome undergoing hip or knee replacement: a case-control study. Mayo Clin Proc 2001;76: 897–905. 21. Livingston EH, Arterburn D, Schifftner TL, Henderson WG, DePalma RG. National Surgical Quality Improvement Program analysis of bariatric operations: modifiable risk factors contribute to bariatric surgical adverse outcomes. J Am Coll Surg 2006;203:625–633. 22. Altermatt FR, Munoz HR, Delfino AE, Cortinez LI. Pre-oxygenation in the obese patient: effects of position on tolerance to apnoea. Br J Anaesth 2005;95:706–709. 23. Gander S, Frascarolo P, Suter M, Spahn DR, Magnusson L. Positive end-expiratory pressure during induction of general anesthesia increases duration of nonhypoxic apnea in morbidly obese patients. Anesth Analg 2005;100:580–584. 24. Combes X, Sauvat S, Leroux B et al. Intubating laryngeal mask airway in morbidly obese and lean patients: a comparative study. Anesthesiology 2005;102:1106–1109. 25. Dhonneur G, Ndoko SK, Yavchitz A et al. Tracheal Intubation of morbidly obese patients: LMA Ctrach vs. direct laryngoscopy. Br J Anaesth 2006;97:742–745. 26. Peterson GN, Domino KB, Caplan RA, et al. Management of the difficult airway. A closed claims analysis. Anesthesiology 2005;103:33–39. 893
articles Intervention and Prevention 27. Erlandsson K, Odenstedt H, Lundin S, Stenqvist O. Positive endexpiratory pressure optimization using electric impedance tomography in morbidly obese patients during laparoscopic gastric bypass surgery. Acta Anaesthesiol Scand 2006;50:833–839. 28. Brodsky JB, Lemmens HJ, Saidman LJ. Obesity, surgery, and inhalation anesthetics—is there a “drug of choice”? Obes Surg 2006;16:734. 29. Brodsky JB, Lemmens HJ, Collins JS et al. Nitrous oxide and laparoscopic bariatric surgery. Obes Surg 2005;15:494–496. 30. De Baerdemaeker LEC, Jacobs S, Den Blauwen NMM et al. Postoperative results after desflurane or sevoflurane combined with remifentanil in morbidly obese patients. Obes Surg 2006;16:728–733. 31. Gaszynski T, Strzelczyk J, Machala W, Gaszynski W. Reduction of a total propofol consumption in morbidly obese patients during general anesthesia due to BIS monitoring. Obes Surg 2005;15:1084. 32. Arain SR, Barth CD, Shankar H, Ebert TJ. Choice of volatile anesthetic for the morbidly obese patient: sevoflurane or desflurane. J Clin Anesth 2005;17:413–419. 33. Strum EM, Szenohradszki J, Kaufman WA et al. Emergence and recovery characteristics of desflurane versus sevoflurane in morbidly obese adult surgical patients: a prospective, randomized study. Anesth Analg 2004;99:1848–1853. 34. Vellejo MC, Sah N, Phelps AL, O’Donnell J, Romeo RC. Desflurane versus sevoflurane for laparoscopic gastroplasty in morbidly obese patients. J Clin Anesth 2007;19:3–8. 35. Albertin A, La Colla G, La Colla L et al. Effect site concentrations of remifentanil maintaining cardiovascular homeostasis in response to surgical stimuli during bispectral index guided propofol anesthesia in seriously obese patients. Minerva Anestesiol 2006;72:915–924. 36. Albertin A, Poli D, La Colla L et al. Predictive performance of ‘Servin’s formula’ during BIS-guided propofol-remifentanil targetcontrolled infusion in morbidly obese patients. Br J Anaesth 2007;98: 66–75. 37. Pandazi A, Bourlioti A, Kostopanagiotou G. Bispectral Index (BIS) monitoring in morbidly obese patients undergoing gastric bypass surgery: experience in 23 patients. Obes Surg 2005;15:58–62. 38. Leykin Y, Pellis T, Del Mestro E et al. Anesthetic management of morbidly obese and super-morbidly obese patients undergoing bariatric operations: hospital course and outcomes. Obes Surg 2006;16: 1563–1569.
894
39. Gaszynski TM, Strzelczyk JM, Gaszynski WP. Post-anesthesia recovery after infusion of propofol with remifentanil or alfentanil or fentanyl in morbidly obese patients. Obes Surg 2004;14:498–503. 40. Pellis T, Leykin Y, Albano G et al. Perioperative management and monitoring of a super-obese patient. Obes Surg 2004;14:1423–1427. 41. Chalhoub V, Yazigi A, Sleilaty G et al. Effect of vital capacity manoeuvres on arterial oxygenation in morbidly obese patients undergoing open bariatric surgery. Eur J Anaesthesiol 2007;24:283–288. 42. Whalen FX, Gajic O, Thompson GB et al. The effects of the alveolar recruitment maneuver and positive end-expiratory pressure on arterial oxygenation during laparoscopic bariatric surgery. Anesth Analg 2006; 102:298–305. 43. Schuster R, Alami RS, Curet MJ et al. Intra-operative fluid volume influences postoperative nausea and vomiting after laparoscopic gastric bypass surgery. Obes Surg 2006;16:848–851. 44. Edmiston CE, Krepel C, Kelly H et al. Perioperative antibiotic prophylaxis in the gastric bypass patient: do we achieve therapeutic levels? Surgery 2004;136:738–747. 45. Squadrone V, Coha M, Cerutti E et al. Continuous positive airway pressure for treatment of postoperative hypoxemia. A randomized controlled trial. JAMA 2005;293:589–595. 46. Battisti A, Michotte JB, Tassaux D, van Gessel E, Jolliet P. Non-invasive ventilation in the recovery room for postoperative respiratory failure: a feasibility study. Swiss Med Wkly 2005;135:339–343. 47. Albala MZ, Ferrigno M. Short-term noninvasive ventilation in the postanesthesia care unit: a case series. J Clin Anesth 2005;17:636–639. 48. McCarty TM. Can bariatric surgery be done as an outpatient procedure? Adv Surg 2006;40:99–106. 49. Watkins BM, Montgomery KF, Ahroni JH et al. Adjustable gastric banding in an ambulatory surgery center. Obes Surg 2005;15:1045–1049. 50. White PF, Kehlet H, Neal JM et al. The role of the anesthesiologist in fasttrack surgery: from multimodal analgesia to perioperative medical care. Anesth Analg 2007;104:1380–1396. 51. von Ungern-Sternberg BS, Regli A, Reber A, Schneider MC. Effect of obesity and thoracic epidural analgesia on perioperative spirometry. Br J Anaesth 2005;94:121–127. 52. Wallace AW, Galindez D, Salahieh A et al. Effect of clonidine on cardiovascular morbidity and mortality after noncardiac surgery. Anesthesiology 2004;101:284–293.
VOLUME 17 NUMBER 5 | MAY 2009 | www.obesityjournal.org
