Patient and procedure selection for an office-based anesthetic

Seminars in Anesthesia, Perioperative Medicine and Pain (2006) 25, 7-12

Patient and procedure selection for an office-based anesthetic Laurence M. Hausman, MD and Isabelle deLeon, MD From the Department of Anesthesiology, Mount Sinai School of Medicine, New York, New York. KEYWORDS: Office-based anesthesia; Patient selection; Procedure selection; Office-based safety

A key element in the delivery of a safe office-based anesthetic is the proper selection of suitable patients and procedures. Currently, there is a paucity of state or local regulations regarding this issue. However, a few medical societies have been active in developing recommendations and practice advisories. Additionally, our experience with free-standing ambulatory surgery centers should help guide in formulating policies that will insure that patient safety is not sacrificed in this exciting new healthcare venue. © 2006 Elsevier Inc. All rights reserved.

Safety in an office-based practice is of paramount importance and involves many factors. Once it has been determined that a particular office is a safe anesthetizing location, and that the surgeon or proceduralist is qualified to perform the proposed procedure, the issue of what types of patients and procedures are acceptable in this venue must be addressed. As of yet, there is very little scientific data that would support excluding particular patients or procedures from the office-based arena. However, lessons learned from our experience in providing anesthetics in hospitals or freestanding ambulatory surgery centers can be extrapolated into this unique surgical setting. Most patients assume that, in an office setting, they will receive the same high quality of care they have come to expect in a hospital. Although this should be a universal truism, some published data would suggest that this might not be the case.1 During the 1990s several high profile deaths occurred in Florida during routine office-based liposuctions. This led to much mass media coverage as well as several scientific studies trying to determine causes.2,3 These morbidities ultimately led to a 90-day moratorium on Address reprint requests and correspondence: Laurence M. Hausman, MD, Department of Anesthesiology, Box 1010, 1 Gustave L. Levy Place, New York, NY 10029. E-mail: [email protected].

0277-0326/$ -see front matter © 2006 Elsevier Inc. All rights reserved. doi:10.1053/j.sane.2005.11.006

all level II and III office-based procedures in that state. During this same time period, there was an increasing amount of state and local legislature regarding the development of standards for office-based surgery and anesthesia. Also, concurrent with this activity, the American Society of Plastic Surgeons (ASPS) convened a task force made up of representatives from its society as well as representatives from the American Society of Anesthesiology (ASA), the state of Florida, and the American Association for Accreditation of Ambulatory Surgery Facilities, Inc. (AAAASF) to develop a practice advisory for office-based surgery and anesthesia.4,5 This task force addressed issues ranging from patient selection and office accreditation to procedure selection.

Patient selection During the formative years of ambulatory surgery centers, it was commonplace to exclude certain patient populations based on issues as arbitrary as advanced patient age. As our experience in this arena grew, so did our comfort in caring for the elderly patient in these freestanding centers. It would therefore seem obvious that, as we try to develop criteria for patient selection for an office-based procedure, we should

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Seminars in Anesthesia, Perioperative Medicine and Pain, Vol 25, No 1, March 2006 Table 1 ASA recommendations for considerations to be taken before performing an office-based anesthetic* ASA physical status Potential or Known Difficult Airway Age Previous problem with anesthesia and/or surgery Current medications Drug allergies NPO status History of substance abuse Presence of an adult escort *Data from ASA: Office-based anesthesia, considerations for anesthesiologists in setting up and maintaining a safe office anesthesia environment.6

not automatically exclude patient populations based on arbitrary criteria such as age alone. In some situations, the elderly may in fact tolerate an office-based anesthetic well. A good example of this is the case of gastro-intestinal (GI) endoscopy. This procedure often involves older patients and has been performed in offices safely for some time. However, it should be appreciated that not all patient populations are appropriate for an office-based procedure. Before commencing with any office-based anesthetic it is imperative that a thorough pre-operative history and physical be performed and an ASA physical status be assigned to the patient. Additionally, any necessary/pertinent laboratory tests should be done, and subspecialty, consultation be obtained as indicated. Since with most office-based cases the anesthesiologist will not have access to the patient until the day of the procedure, the surgical office scheduling desk as well as the physician doing the pre-operative history and physical, should be familiar with the ASA physical status classification and its implications. The desk clerk can be instructed to schedule any ASA physical status 1 or 2 patient as per protocol. Patients classified as an ASA physical status 3 or greater should prompt a pre-scheduling phone call to the anesthesiologist. This will alleviate the need for a case to be “cancelled” on the day of the procedure, which will be discussed later in this text. It may even be helpful to have a pre-printed history and physical form available for each patient. Having a standardized form will help to assure that all anesthetic and surgical issues are addressed in a uniform fashion. It should be mentioned that, although the anesthesiologist will often not have access to the patient prior to the day of surgery, he/she could still review the chart and contact the patient by telephone. This telephone call will not only allow the anesthesia provider to formulate a tailored anesthetic plan, but will often help to alleviate patient worry and concern. Holding the physician performing the initial history and physical responsible for assigning an ASA physical status to the patient is of vital importance. The ASPS task force has recommended that patients who are assigned an ASA physical status 1 or 2 are “reasonable candidates for the officebased surgery setting,” whereas ASA physical status 3 pa-

tients “may also be reasonable candidates for office-based surgery facilities when local anesthesia, with or without sedation, is planned and the facility is accredited”; however, ASA physical status 4 patients “are appropriate candidates for the office-based surgery setting only when local anesthesia without sedation is planned.”5 The ASA has made similar recommendations.6 They recommend that a patient with an ASA physical status class of 1 or 2 be scheduled for the procedure in the usual fashion. However, the anesthesiologist prior to the day of the procedure should see those patients with a physical status of 3 or higher, thus giving the anesthesia provider optimal time to help direct patient evaluation and surgical scheduling. The ASA has also suggested specific factors that should be taken into consideration before embarking on an office-based anesthetic (Table 1). Additionally, they cautioned against performing an officebased anesthetic on any patient less than 6 months of age or any premature infant in which post-operative apnea is still an issue. In addition to the considerations made by the ASA, the anesthesiologist should also be mindful of patients with other risk factors of surgery such as the risk of developing deep venous thrombosis (DVT) and/or pulmonary embolisms (PE) (Table 2). A recent article by The Doctors Company, a medical malpractice insurance company, reviewed 12 recent malpractice claims involving PE after an officebased plastic surgery procedure. All of the claims involved patients ages 31 through 64 with a mean age of 47. Eleven of the patients were female and 1 was male. Eight of the 12 patients had undergone an abdominoplasty, and 6 of these 8 had undergone other procedures at the same time. Only 50% of the patients had undergone general anesthesia. Nine of the 12 patients in this report died.7 Death following these types of procedures has been reported, and DVT with subsequent PE is a significant risk of abdominoplasty and liposuction, 2 very common office-based procedures. It may even be the leading cause of postoperative death for these patients.8 Thus, any office-based practitioner should be aware of this patient class and be very knowledgeable about issues of prevention and treatment for both DVT and PE. The morbidly obese patient also presents a unique challenge to the office-based anesthesiologist during the perioperative period.9 Obesity is usually determined in relation to the body mass index (BMI). BMI is defined as mass/

Table 2

Patients with increased risk of DVT

Elderly Malignancy Smokers Obese Oral contraceptive users Patients on bed rest Malignancy Hypercoagulable History of DVT ?General anesthetics greater than 1 hour

Hausman and deLeon Table 3

Patient and Procedure Selection

BMI scale*

Underweight Normal Overweight Obesity Morbid obesity

BMI BMI BMI BMI BMI

⬍ ⫽ ⫽ ⫽ ⬎

19.0 19–24.9 25–29.9 30.0–34.9 35

*Data from World Health Organization, 1998.22

height2. This number can be calculated as kg/meter2 or (703 ⫻ weight in pounds)/inches2. BMI ranges from underweight through morbid obesity (Table 3). Obesity is associated with many co-morbidities, including obstructive sleep apnea syndrome (OSAS).10 Furthermore, obese and morbidly obese patients are usually considered to be a “full stomach” and therefore would require a rapid sequence induction for general anesthesia. These patients also are generally not suitable for surgery with monitored anesthesia care (MAC). Anesthesia is a continuum ranging from minimum sedation to general anesthesia. An attempt at MAC may quickly convert to a general anesthetic with loss of protective airway reflexes. This potential situation makes MAC for this patient group inadvisable. Due to a number of physiologic parameters, such as reduced pharyngeal area, redundant soft tissue of the pharynx, and enlarged breasts, obese and morbidly obese patients may be difficult to intubate and/or ventilate if need be.9 This creates an ominous situation in the office-based practice since one of the initial steps in the ASA algorithm for the unanticipated difficult airway is to call for help.11 In the office, that help will usually not be present. Even if the anesthesia provider decides to proceed with the case, and the patient has been successfully intubated, the problem with that particular obese patient has not been solved. Because these patients may also have OSAS, they will most likely have an increased sensitivity to the respiratory depressant effects of anesthetics and narcotics, thereby predisposing them to apnea during the post-operative period. This apnea is often resistant to the reversal effects of nalaxone. Because of this, some authors have advocated closely observing all OSAS patients postoperatively for periods of time that would be impractical in the office-based setting.12,13 In light of these facts, it would seem reasonable to avoid performing an office-based anesthetic on any patient with documented OSAS. Since most patients with OSAS have yet to be diagnosed,14 a patient suspected to have this condition (loud snoring, nocturnal apneic events, obese, daytime somnolence, large neck circumference) might warrant a sleep study prior to determining whether or not they will be an acceptable office-based patient. Similarly, it would seem prudent to avoid performing an office-based anesthetic on any patient with a BMI greater than 35, and require a pre-anesthesia consultation with an anesthesiologist prior to the day of surgery for any patient with a BMI of 30-34.9. This would give the anesthesia provider the opportunity to determine whether the particular patient is a

9 suitable candidate for an office-based procedure in a less time-pressured environment. Obesity is a growing international epidemic,15 and consequently we will be faced with an increasing number of obese and morbidly obese patients in all types of anesthesia practices. These patients will most likely be presenting to surgical offices for procedures in increasing numbers as well. It is important to have addressed this issue with each office that one has a business relationship with in advance. It is important to remember that, although these suggestions and other recommendations may not represent the standard of care, it is essential for the office-based practitioner to consider all co-morbidities when deciding whether a patient is a suitable candidate for an office-based procedure. Moreover, there must be an open and honest communication between the anesthesia provider and the surgeon dealing with what types of patients should and should not be operated on in the office setting. The anesthesia provider must not feel pressured to push the limits of patient safety to satisfy either surgeon or even patient demands. It is usually helpful to have discussions and possibly printed material available to the surgeon or proceduralist dealing with patient selection prior to initiating a professional relationship. Table 4 gives a typical example of patients that may not be suitable for an office-based anesthetic.

Procedure selection Recent advances in surgical technology and equipment along with improved anesthetic techniques and drugs have made the office-based setting the appropriate site for numerous surgical procedures once suitable only for hospitals or ambulatory surgery centers. Furthermore, these newer procedures being performed in surgical offices have increased in complexity, degree of invasiveness, and duration. As with patient selection, there is very little, if any, hard scientific data to exclude specific procedures or specific procedure durations from the office-based arena. Additionally, as with patient selection, our experience with ambulatory surgery centers may warn against setting arbitrary standards of suitability for an office-based procedure. Many of the medical specialties and societies that are involved in this

Table 4 Example of patients that the practitioner may choose to exclude from an office-based procedure ASA physical status 3 or 4 Substances abusers Brittle/poorly controlled diabetics Seizure disorder Malignant hyperthermia susceptible Morbid obesity/OSAS Aspiration risk Age ⬍6 months No escort

10 Table 5

Seminars in Anesthesia, Perioperative Medicine and Pain, Vol 25, No 1, March 2006 Commonly performed office-based procedures

Cosmetic Facial-Facelift Blepharoplasty Rhinoplasty Meloplasty Brow lift Facial resurfacing Body-Liposuction Breast augment/reduction/mastopexy Abdominoplasty Arm and leg lift Gastrointestinal Endoscopy Upper endoscopy (esophageal, gastric, duodenal) Colonoscopy Dentistry and Oral and Maxillofacial Surgery Tooth, especially wisdom, extraction Pediatric dentistry Orthopedics and Podiatry Arthroscopy (knee, shoulder, elbow) Wrist, hand and foot surgery Gynecology and Urology Dilatation and curettage Hysteroscopy and mini-laparoscopies Ovum retrieval Vasectomy Cystoscopy Prostate biopsy, laser resection Lithotripsy Ophthalmology and Otolaryngology Cataract extraction Lacrimal duct probing Ocular plastics Endoscopic sinus surgery Turbinate resection Septoplasty Myringotomy

type of health care delivery have made recommendations regarding which types of procedures should be performed in an office, and which are better suited for a hospital or free-standing ambulatory surgery center. The ASPS task force on office-based surgery has recommended that procedures not exceed 6 hours in duration and be completed by 3:00 PM to allow for sufficient recovery time with adequate staffing.4 Procedures that involve or might result in hypothermia, excessive blood loss, or significant fluid shifts are also not suitable for this type of setting.4 Additionally, one must consider the post-operative course of any patient having surgery in an office. If the procedure is associated with significant post-operative pain or immobility, it may be advisable to perform it in a hospital. Ultimately, the patient’s overall health status as well as his/her anticipated peri-operative course is crucial in determining what type of procedure can safely be performed in the office setting. What is considered an acceptable office-based surgical procedure for one patient may not be acceptable for another. Procedures commonly performed in offices scan many of the surgical subspecialties (Table 5). Plastic surgery has long been the mainstay of office-based surgery, and the

specific case of liposuction brings out some important points regarding patient safety.

Office-based liposuction Despite numerous highly publicized fatalities associated with it, liposuction continues to be one of the most commonly performed cosmetic surgical procedures in the office-based practice.16 It is a successful and safe alternative to diet and/or exercise for improving body contour resulting from lipodystrophy. However, it has not been shown to be helpful in the treatment of obesity. Additionally, high volume liposuction (⬎5 liters) is associated with a much higher morbidity and mortality rate than liposuction of smaller volumes. This will be discussed later in this section. The liposuction procedure involves the surgical removal of adipose tissue from subcutaneous space via a blunt tip hollow cannula attached to a high-powered suction catheter or aspirator. During the early years of liposuction, the “dry” technique was the one most commonly performed. With this method, no subcutaneous infiltrate solution was placed prior to insertion of the liposuction cannula. As a result, patients often suffered significant pain, swelling, skin discoloration, and blood loss, sometimes requiring hospitalization and/or blood transfusion. Additionally, not much adipose tissue could be removed with this method. Current liposuction techniques incorporate the use of subcutaneous infiltrate solutions, usually 0.9% NaCl or lactated Ringer’s solution, with or without epinephrine or local anesthetics, such as lidocaine or bupivicaine, to limit the consequences of the dry technique. The “wet” technique of the early 1980s involved injecting 200-300 cc of infiltrate solution with or without epinephrine. This improvement lowered the blood loss to between 4% and 30% of the aspirate. The “superwet” and “tumescent” technique further decreased blood loss to less than 1% of the aspirate volume. This technique involves injecting 1 cc of infiltrate solution (superwet) and 3 to 4 cc of infiltrate solution (tumescent), for each 1 cc of fat to be aspirated.15 The addition of vasoconstrictors such as epinephrine (dosages ranging from 1:100,000 to 1:1,000,0000) to the infiltrate solution offers several advantages. It significantly decreases blood loss from improved hemostasis, and it delays the systemic absorption of local anesthetic, thereby reducing the risk of local anesthetic toxicity and limiting total local anesthetic dose. The addition of local anesthetics to the infiltrate solution, in particular lidocaine (because of its excellent safety profile), provides preemptive and postoperative local analgesia, thus reducing or eliminating the need for sedation, general anesthesia, or epidural anesthesia. Acceptable lidocaine dose for infiltrative solution containing epinephrine is 35 to 50 mg/kg, much higher than the usual recommended dose of 7 mg/kg.17,18 This is due to lidocaine’s slow absorption in the poorly vascularized fatty tissue, the vasoconstrictive effect of epinephrine further delaying its absorption, and the fact that it is quickly aspi-

Hausman and deLeon

Patient and Procedure Selection

rated as part of the fat aspirate. The injected lidocaine follows a two-compartmental model of elimination in this type of technique with peak levels occurring at approximately 12 to 14 hours after injection and declining over the next 6 to 14 hours.17 Recent advances in liposuction techniques, as well as our better understanding of the physiological consequence of liposuction, have made both minor and major body contouring safe and effective. Nevertheless, minor and major complications can arise as a result of this procedure. Minor complications include hematomas, seromas, and minor skin irregularities. Serious adverse events include local anesthetic toxicity, fluid overload, skin and/or organ perforation, infection, major contour defects, skin necrosis, thermal injury, anesthetic reaction, hypotension without shock, hemorrhage, pulmonary embolus, and fat embolus.8,19 Proper patient selection and preoperative evaluation, close perioperative management of pain and fluid/electrolyte imbalance, as well as vigilant monitoring for complications are important contributing factors in reducing or eliminating these serious complications. Presently, liposuction is performed primarily by plastic surgeons and dermatologists, and is associated with an overall death rate reported at as high as 1/5000.8 This same study revealed that 45% of the deaths occurred after an officebased procedure. This is significant because liposuction is commonly performed in that venue, and usually on a healthier group of patients than those in a hospital. However, not all published data regarding office-based surgery and anesthesia have similar findings. A survey sent to 505 of the 517 worldwide members of the American Society for Dermatologic Surgery in August of 2001 revealed that the vast majority of the liposuction cases (71%) are being done in an office as opposed to in the hospital (4%) or free standing ambulatory surgery center (23%).18 This survey had an 89% response rate (450/505). Seventy-eight percent of the respondents (349/450) performed liposuction, and 261 of them gave information dealing with 66,570 cases of liposuction. The mean number of procedures for each practitioner was 255, with a range of 0 to 3014. Eighty-eight percent of the respondents (232/265) claimed no serious adverse outcomes, with an overall morbidity rate of 0.68%. In this survey, it was also found that the morbidity associated with liposuction was related to the area of the body being operated on. The highest complication rate was seen with liposuction of the abdomen (72%), followed by the buttocks and lower extremities (39%), the upper extremities (3%), the upper back (14%), lower back (8%), and head and neck (6%). Interestingly there were no mortalities in this survey.18 It is important to remember that most of the data regarding morbidity and mortality for office-based procedures have been done retrospectively with surveys. No prospective double-blinded studies have yet to appear in the literature. This type of information would be helpful for the advancement of this sub-specialty.

11 Fluid management during liposuction is of extreme importance. It has been recommended that large volume liposuction (greater than 5 liters) only be performed in a hospital or accredited facility.20 When 5 liters of aspirate are removed, significant fluid shifts may occur and a large fluid deficit should be expected. These patients should be watched closely, often overnight for possible fluid overload, an option usually not available in an office-based practice. Additionally, multiple area liposuction also carries unique challenges to the anesthesia provider. Careful positioning to avoid peripheral nerve injuries must always be addressed. This becomes even more of an issue because of multiple periods of patient repositioning during the procedure. Additionally, it should be noted that, during these times of repositioning, the endotracheal tube, or more commonly the laryngeal mask airway, might become dislodged. Thus, as always, there is no substitute for vigilance on the part of the anesthesiologist. As with all areas of anesthesia, a clear understanding of the surgical procedure being performed and its physiologic impact is essential if an anesthetic is to be delivered in a safe and effective manner. One must not be fooled into thinking that a cosmetic procedure is simple and always safe.

The case of endoscopy Upper gastro-esophago-duodenoscopy (EGD) and lower colonoscopies have long been performed in physicians’ offices. These procedures involve intubating the digestive tract with an endoscope and are associated with significant discomfort and cardiovascular events.21 GI endoscopic procedures serve to highlight important office-based issues. First, the patient population tends to be older and sometimes with significant co-morbidities. Consequently, not all of these patients are suitable for the office. It is important to establish which co-morbidities are unacceptable in this venue. For example, one may choose to exclude the morbidly obese, or brittle diabetic, and refer these patents to a hospital-based endoscopic center. The endoscopist must team with the anesthesia provider as champions of patient safety. If the anesthesiologist simply refuses to sedate a specific patient in the office, the endoscopist might choose to perform his/her own sedation. This choice will most likely not be in the patient’s best interest, in terms of comfort or safety. Anesthetic technique is another important issue when evaluating a patient for an endoscopy. Many patients scheduled to undergo an EGD have documented gastro-esophageal reflux. The standard anesthesia teaching would recommend securing the airway via a rapid sequence induction. This is usually not the case. The reasoning behind the decision to proceed with an unsecured airway is that the patient will lose airway reflexes for a short period of time, and the stomach will be immediately suctioned under direct vision. Whether or not this is truly a sound decision needs

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Seminars in Anesthesia, Perioperative Medicine and Pain, Vol 25, No 1, March 2006

to be studied prospectively. It should be mentioned that the anesthesiologist must be vigilant throughout the procedure and have his/her own independent suction readily available. In the past, the endoscopist or a nurse performed the sedation for office endoscopies. The commonly used anesthetic agents at the time included diazapam and demerol. This drug combination often led to the patient being uncomfortable during the procedure and required long periods of time for recovery. Nalaxone was not uncommonly used during the recovery period. As anesthesiologists have moved into this venue, midazolam, propofol, and fentanyl have become popular agents. This drug regimen makes the procedure more comfortable for the patient and provides the endoscopist with an immobilized subject on which to work. However, an anesthesiologist competent in managing an unprotected airway, and familiar with the anesthesia continuum, must administer it. This is because propofol has a significant risk of apnea across a range of dosages. Although there is movement afoot to allow GI endoscopists to administer this drug without the aid of an anesthesiologist, patient safety would be compromised.

Conclusion Office-based anesthesia is a popular new location for providing high quality medical care at a reduced price, with improved convenience for the patient and practitioner. However, not all patients and procedures are the same, and thus not all are suitable for this type of venue. Anesthesiologists have long been the champions of patient safety. This active involvement should continue, and we must not take steps backwards in this new, largely unregulated setting. It is incumbent upon us to insist that the high standard of care achieved in hospitals and ambulatory surgery centers is duplicated in every office in which surgery and anesthesia are performed.

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3. Coldiron B: Office surgical incidents: 19 months of Florida data. Dermatol Surg 28:710-712, 2002 4. Iverson RE, ASPS Task Force on Patient Safety in Office-based Surgery Facilities: Patient safety in office-based surgery facilities. I. Procedures in the office based surgery setting. Plastic Reconstruct Surg 110:1337-1342, 2002 5. Iverson RE, Lynch DJ, ASPS Task Force on Patient Safety in Officebased Surgery Facilities: Patient safety in office-based surgery facilities. II. Patient selection. Plastic Reconstruct Surg 110:1785-1790, 2002 6. The ASA Committee on Ambulatory Surgical Care and the ASA Task Force on Office-Based Anesthesia. American Society of Anesthesiologists. Office-based anesthesia, considerations for anesthesiologists in setting up and maintaining a safe office anesthesia environment. Park Ridge, IL, 2000 7. Lofsky AS: Deep Venous Thrombosis and Pulmonary Embolism in Plastic Surgery Office Procedures. http://www.thedoctors.com/risk/ specialty/anesthesiology/J4254.asp. Accessed October 12, 2005 8. Grazer FM, deJong RH: Fatal outcome from liposuction: census survey of cosmetic surgeons. Plastic Reconstruct Surg 105:436-446, 2000 9. Benumof JL: Obstructive sleep apnea in the adult obese patient: implications for airway management. Anesthesiol Clin N Am 20:789811, 2002 10. Strohl KP, Redline S: Recognition of obstructive sleep apnea. Am J Respir Crit Care Med 143:279-286, 1996 11. http://www.asahq.org/publicationsAndServices/Difficult%20Airway. pdf. Accessed October 12, 2005 12. Lofsky A: Sleep apnea and narcotic postoperative pain medication: a morbidity and mortality risk. APSF Newsletter 17:24-25, 2002 13. Benumof JL: Creation of observational unit may decrease sleep apnea risk. APSF Newsletter 17:39, 2002 14. Young T, Evans L, Finn L, et al: Estimation of the clinically diagnosed proportion of sleep apnea syndrome in middle-aged men and women. Sleep 20:705-706, 1997 15. http://www.who.int/dietphysicalactivity/media/en/gsfs_obesity.pdf. Accessed October 12, 2005 16. Rohrich RJ, Haydon MS: Body mass index: risk predictor for cosmetic day surgery. Plastic Reconstruct Surg 108:562-563, 2001 17. Klein JA: Tumescent technique for regional anesthesia permits lidocaine doses of 35 mg/kg. J Dermatol Surg Oncol 16:248-263, 1990 18. Ostad A, Kageyama N, Moy RL: Tumescent anesthesia with lidocaine dose of 55 mg/kg is safe for liposuction. Dermatol Surg 22:921-927, 1996 19. Houseman TS, Lawrence N, Mellen BG, et al: The safety of liposuction: results of a national survey. Dermatol Surg 28:971-978, 2002 20. The ASPS Committee on Patient Safety.Iverson RE, Lynch DJ, Practice advisory on liposuction. Plastic Reconstruct Surg 113:1478-1490, 2004 21. Puchner R, Allinger S, Doblhofer F, et al: Complications of diagnostic interventional colonoscopy. Wien Klin Wochenschr 108:142-145, 1996 22. World Health Organization. Obesity: preventing and managing the global epidemic: report of a WHO consultation on obesity, Geneva, June 3-5, 1997