Extensive preoperative testing is not necessary in morbidly obese patients undergoing gastric bypass

Preoperative Laboratory Testing

Obtaining routine preoperative laboratory tests increases health care costs and has been listed, by the Choosing Wisely Campaign, as one of the top 5 practices anesthesiologists should avoid. Routine testing without clinical indication is not cost-effective and could cause harm and unnecessary delays. Abnormal findings are more likely to be false positive and costly to pursue, introduce new risks, and increase anxiety for the patient. Preoperative testing need to be performed only following a targeted history and physical examination, factoring severity of surgery, and comorbidities such that the benefit of the test outweighs risk.

Outpatient parathyroid surgery and the differences seen in the morbidly obese

Objective

This prospective study examined rapid patient discharge after routine parathyroidectomy to identify differences between morbidly obese and non-morbidly obese patients. The efficacy of supplemental calcium in preventing postoperative hypocalcemia was also assessed.

Methods

Between March 2003 and June 2004, 842 patients with primary hyperparathyroidism underwent outpatient parathyroid surgery. Morbid obesity was defined as 100 pounds above ideal body weight and/or body mass index greater than 39.

Results

Fifty-one (6.1%) patients were morbidly obese (mean, 261 lbs; body mass index = 45) compared with 791 non-morbidly obese patients (mean, 172 lbs; body mass index = 28, P < .001). Morbidly obese patients were more likely to require conversion of laryngeal masked airway to endotracheal intubation ( P < .05). Incision length, total operative times, and the total time spent in the post-anesthesia care unit were longer for morbidly obese patients (all, P < .05). Of the 842 patients, only four, all non-morbidly obese, spent the night after their operation. No postoperative untoward events occurred in either group.

Conclusions

Immediate discharge after routine parathyroid surgery is extremely safe for nearly all patients although morbid obesity is associated with a longer operation, a more difficult airway, and a longer stay in the recovery room.

[Screening prior to surgery and interventions]

Routine preoperative screening is often performed but seldom indicated. The evidence for such procedures is weak or lacking. Advanced patient age is also not a reasonable trigger to initiate testing. Obtaining a detailed, standardized bleeding history, for example using a questionnaire, is much more valuable than blind testing for coagulation parameters. Of primary importance are a detailed medical history with special focus on the patient's individual fitness and a thorough physical examination. Specific blood tests may then follow. Renal function tests are indicated as routine if major surgery with intraoperative volume restriction is planned. Routine preoperative chest radiography is almost never indicated.

Anesthetic management of patients undergoing bariatric surgery: two year experience in a single institution in Switzerland

BACKGROUND

In the field of anesthesia for bariatric surgery, a wide variety of recommendations exist, but a general consensus on the perioperative management of such patients is missing. We outline the perioperative experiences that we gained in the first two years after introducing a bariatric program.

METHODS

The perioperative approach was established together with all relevant disciplines. Pertinent topics for the anesthesiologists were; successful airway management, indications for more invasive monitoring, and the planning of the postoperative period and deposition. This retrospective analysis was approved by the local ethics committee. Data are mean [SD].

RESULTS

182 bariatric surgical procedures were performed (147 gastric bypass procedures (GBP; 146 (99.3%) performed laparascopically). GBP patients were 43 [10] years old, 78% female, BMI 45 [7] kg/m(2), 73% ASA physical status of 2. 42 patients (28.6%) presented with obstructive sleep apnea syndrome. 117 GBP (79.6%) patients were intubated conventionally by direct laryngoscopy (one converted to fiber-optic intubation, one aspiration of gastric contents). 32 patients (21.8%) required an arterial line, 10 patients (6.8%) a central venous line. Induction lasted 25 [16] min, the procedure itself 138 [42] min. No blood products were required. Two patients (1.4%) presented with hypothermia (<35 °C) at the end of their case. The emergence period lasted 17 [9] min. Postoperatively, 32 patients (21.8%) were transferred to the ICU (one ventilated). The other patients spent 4.1 [0.7] h in the post anesthesia care unit. 15 patients (10.2%) required take backs for surgical revision (two laparotomies).

CONCLUSIONS

The physiology and anatomy of bariatric patients demand a tailored approach from both the anesthesiologist and the perioperative team. The interaction of a multi-disciplinary team is key to achieving good outcomes and a low rate of complications.

TRIAL REGISTRATION

DRKS00005437 (date of registration 16(th) December 2013).

Review article: The nutritional and pharmacological consequences of obesity surgery

BACKGROUND

Obesity surgery is acknowledged as a highly effective therapy for morbidly obese patients. Beneficial short-term effects on common comorbidities are practically undisputed, but a growing data pool from long-term follow-up reveals increasing evidence of potentially severe nutritional and pharmacological consequences.

AIMS

To assess the prevalence, causes and symptoms of complications after obesity surgery, to elucidate and compare therapy recommendations for macro- and micronutrient deficiencies, and to explore surgically-induced effects on drug absorption and bioavailability, discussing ramifications for long-term therapy and prophylaxis.

METHODS

PubMed, Embase and MEDLINE were searched using terms including, but not limited to, bariatric surgery, gastric bypass, obesity surgery and Roux-en-Y, coupled with secondary search terms, e.g. anaemia, micronutrients, vitamin deficiency, bacterial overgrowth, drug absorption, pharmacokinetics, undernutrition. All studies in English, French or German published January 1980 through March 2014 were included.

RESULTS

Macro- and micronutrient deficiencies are common after obesity surgery. The most critical, depending on surgical technique, are hypoalbuminemia (3-18%) and deficiencies of vitamins B1 (≤49%), B12 (19-35%) and D (25-73%), iron (17-45%) and zinc (12-91%). Many drugs commonly administered to obese patients (e.g. anti-depressants, anti-microbials, metformin) are subject to post-operative and/or PPI-associated changes affecting bioavailability and absorption.

CONCLUSIONS

Complications are associated with pre-operative and/or post-operative malnutrition or procedure-related changes in intake, absorption and drug bioavailability. The high prevalence of nutrient deficiencies after obesity surgery makes life-long nutritional monitoring and supplementation essential. Post-operative changes to drug absorption and bioavailability in bariatric patients cast doubt on the validity of standard drug dosage and administration recommendations.

Nutrient deficiencies after gastric bypass surgery

Bariatric surgery, and in particular, gastric bypass, is an increasingly utilized and successful approach for long-term treatment of obesity and amelioration of comorbidities. Nutrient deficiencies after surgery are common and have multiple causes. Preoperative factors include obesity, which appears to be associated with risk for several nutrient deficiencies, and preoperative weight loss. Postoperatively, reduced food intake, suboptimal dietary quality, altered digestion and absorption, and nonadherence with supplementation regimens contribute to risk of deficiency. The most common clinically relevant micronutrient deficiencies after gastric bypass include thiamine, vitamin B₁₂, vitamin D, iron, and copper. Reports of deficiencies of many other nutrients, some with severe clinical manifestations, are relatively sporadic. Diet and multivitamin use are unlikely to consistently prevent deficiency, thus supplementation with additional specific nutrients is often needed. Though optimal supplement regimens are not yet defined, most micronutrient deficiencies after gastric bypass currently can be prevented or treated by appropriate supplementation.

Medical complications of obesity and optimization of the obese patient for colorectal surgery

Obesity is a medical epidemic with an enormous impact on disease prevalence and health care utilization. In the preoperative period, an awareness of medical issues associated with obesity is an important part of the planning for surgical procedures. The authors highlight the diagnostic and treatment options for medical conditions commonly affecting the obese patient including diabetes, hypertension, coronary artery disease, and deep venous thrombosis.

Anaesthesia for bariatric surgery

Although many smaller studies have addressed anaesthetic care for bariatric surgical patients, comprehensive systematic literature reviews have yet to be compiled, and much evidence includes expert panel opinion. This review summarises study results in bariatric surgical patients regarding pre-anaesthesia evaluation, the perioperative impact of sleep-disordered breathing, airway management at anaesthetic induction and emergence, maintenance of anaesthesia, postoperative pain management, utility of clinical-care pathways and feasibility of outpatient bariatric surgery. The 'ramped' upper-body, reversed Trendelenburg position at anaesthetic induction and manual application of positive end-expiratory pressure (PEEP) is recommended. Intra-operative hypoxaemia can be treated with the combination of PEEP and recruitment manoeuvres, and attention to airway management at emergence is critical. Local anaesthetic wound infiltration and non-steroidal anti-inflammatory drugs should be part of multimodal opioid-sparing postoperative analgesia. Implementation of bariatric clinical-care pathways seems beneficial. Considering the prevalence of sleep apnoea in these patients, outpatient bariatric surgery remains controversial, but is probably safe for certain procedures, provided there is strict adherence to preoperative eligibility and home-care protocols.

Obesity, metabolic syndrome, and the surgical patient

Contemporary life, with its sedentary lifestyles, fast foods, processed foodstuff, and desk-bound service employment, is beset by an epidemic of overweight and obese individuals. The World Health Organization reported that worldwide a billion adults are overweight and at least 30% of them are obese. Moreover, increasing numbers of children are obese. In the United States, 2 National Health and Nutrition Examination Surveys of adults aged 20 to 74 years showed that the prevalence of obesity increased from 15% in the 1976 to 1980 survey to 34% in the 2003 to 2004 survey. Obesity and the metabolic syndrome are unfortunately becoming increasingly common perioperative issues. The ultimate aim of caring for such patients is to find ways to minimize the untoward effects of surgery in patients who are obese or have metabolic syndrome.

Obesity, metabolic syndrome, and the surgical patient

Contemporary life, with its sedentary lifestyles, fast foods, processed foodstuff, and desk-bound service employment, is beset by an epidemic of overweight and obese individuals. The World Health Organization reported that worldwide a billion adults are overweight and at least 30% of them are obese. Moreover, increasing numbers of children are obese. In the United States, 2 National Health and Nutrition Examination Surveys of adults aged 20 to 74 years showed that the prevalence of obesity increased from 15% in the 1976 to 1980 survey to 34% in the 2003 to 2004 survey. Obesity and the metabolic syndrome are unfortunately becoming increasingly common perioperative issues. The ultimate aim of caring for such patients is to find ways to minimize the untoward effects of surgery in patients who are obese or have metabolic syndrome.

Obesity, Weight Management, and Health Care Costs: A Primer

Rational decision-making regarding health care spending for weight management requires an understanding of the cost of care provided to obese patients and the potential cost-effectiveness or cost savings of interventions. The purpose of this review is to assist health plans and disease management leaders in making informed decisions for weight management services. Among the review's findings, obesity and severe obesity are strongly and consistently associated with increased health care costs. The cost-effectiveness of obesity-related interventions is highly dependent on the risk status of the treated population, as well as the length, cost, and effectiveness of the intervention. Bariatric surgery offers high initial costs and uncertain long-term cost savings. From the perspective of a payor, obesity management services are as cost-effective as other commonly offered health services, though not likely to offer cost savings. Behavioral health promotion interventions in the worksite setting provide cost savings from the employer's perspective, if decreased rates of absenteeism are included in the analysis.

Perioperative care of patients undergoing bariatric surgery

The epidemic of obesity in developed countries has resulted in patients with extreme (class III) obesity undergoing the full breadth of medical and surgical procedures. The popularity of bariatric surgery in the treatment of extreme obesity has raised awareness of the unique considerations in the care of this patient population. Minimizing the risk of perioperative complications that contribute to morbidity and mortality requires input from several clinical disciplines and begins with the preoperative assessment of the patient. Airway management, intravenous fluid administration, physiologic responses to pneumoperitoneum during laparoscopic procedures, and the risk of thrombotic complications and peripheral nerve injuries in extremely obese patients are among the factors that present special intraoperative challenges that affect postoperative recovery of the bariatric patient. Early recognition of perioperative complications and education of the patient regarding postoperative issues, including nutrition and vitamin supplementation therapy, can improve patient outcomes. A suitable physical environment and appropriate nursing and dietetic support provide a safe and dignified hospital experience. This article reviews the multidisciplinary management of extremely obese patients who undergo bariatric surgery at the Mayo Clinic.

Resolution of hyperlipidemia after laparoscopic Roux-en-Y gastric bypass

BACKGROUND

Hyperlipidemia is an established risk factor for development of coronary artery disease. The aim of our study was to examine the changes in serum lipid profiles of morbidly obese patients complicated by hyperlipidemia, who underwent laparoscopic gastric bypass.

STUDY DESIGN

We retrospectively reviewed the charts of 95 morbidly obese patients with documented hyperlipidemia who underwent laparoscopic gastric bypass. Mean duration of hyperlipidemia was 44+/- 56 months. Hyperlipidemia was defined as an elevated level of triglycerides (> 150 mg/dL) or total cholesterol (> 200 mg/dL). Changes in lipid profile of a subset of patients with subnormal levels of high-density lipoprotein cholesterol (<or= 40 mg/dL), high levels of low-density lipoprotein cholesterol (> 130 mg/dL), and very-low-density lipoprotein cholesterol (> 40 mg/dL) were also examined. Fasting lipid profiles were measured preoperatively and at 3-month intervals.

RESULTS

There were 68 women (72%) with a mean age of 43 +/- 10 years. Mean body mass index was 47+/- 5 kg/m2. Mean percentage of excess body weight loss at 12 months postoperatively was 66%. One year after gastric bypass, mean total cholesterol levels decreased by 16%; triglyceride levels decreased by 63%; low-density lipoprotein cholesterol levels decreased by 31%; very-low-density lipoprotein cholesterol decreased by 74%; total cholesterol/high-density lipoprotein cholesterol risk ratio decreased by 60%, and high-density lipoprotein cholesterol levels increased by 39%. Also, within 1 year, 23 of 28 (82%) patients requiring lipid-lowering medications preoperatively were able to discontinue their medications.

CONCLUSIONS

Weight loss after laparoscopic gastric bypass substantially improves lipid profiles in morbidly obese patients who have hyperlipidemia. Improvement in lipid profiles was observed as early as 3 months postoperatively and was sustained at 1 year. Improvement of lipid profiles after laparoscopic gastric bypass can reduce health risks associated with high levels of atherogenic lipoproteins.

Perianesthesia respiratory care of the bariatric patient

Our nation's obesity problem has reached epidemic proportions and is only projected to worsen. The morbidly obese patient is at risk for experiencing a multitude of health-related conditions. Morbidly obese patients are presenting for surgery at an increasing rate, especially with the growing popularity of weight-loss surgery. Therefore the perianesthesia nurse has to remain informed of optimal care strategies for this sometimes challenging population. The obese patient presents with distinct respiratory care considerations of which the perianesthesia nurse must be knowledgeable. This review article will specifically focus on the respiratory care of the bariatric patient presenting for surgery.

Surgical treatment of morbid obesity

Obesity is a major epidemic in developed countries. It induces or exacerbates hypertension, diabetes mellitus, obstructive sleep apnea, dyslipidemia, and many other disease processes, which cumulatively contribute to premature mortality on a scale rivaling that of smoking. At present, bariatric surgery is the only therapeutic modality that can produce sustained weight loss and halt or resolve comorbidities. This success results from the ability to perform the operation reliably, usually laparoscopically, with low mortality. The most commonly performed operation is Roux-en-Y gastric bypass. Other bypasses discussed in this review include biliopancreatic diversion with and without duodenal switch. Purely restrictive operations, especially adjustable gastric banding, have a lower risk but are somewhat less effective. We focus on the more controversial aspects of commonly accepted operations, including patient selection, the spectrum and frequency of complications, and the long-term outcome.

Preoperative Evaluation of Patients with Obesity and Obstructive Sleep Apnea

Obesity and obstructive sleep apnea are conditions frequently encountered by the anesthesiologist and may have a significant impact on perioperative outcomes. This article discusses the preoperative evaluation of patients with one or both of these conditions. The goals of the preoperative assessment are to identify issues that can adversely affect the patient. This information is critical to forming an effective plan for the perioperative care of the patient.

Best practice recommendations for anesthetic perioperative care and pain management in weight loss surgery

OBJECTIVE

To develop evidence-based recommendations that optimize the safety and efficacy of perioperative anesthetic care and pain management in weight loss surgery (WLS) patients.

RESEARCH METHODS AND PROCEDURES

This Task Group examined the scientific literature on anesthetic perioperative care and pain management published in MEDLINE from January 1994 to March 2004. We also reviewed additional data from other sources (e.g., book chapters). The search yielded 195 abstracts, of which 35 references were reviewed in detail. Task Group consensus was used to provide recommendations when evidence in the literature was insufficient.

RESULTS

We developed anesthesia practice and patient safety advisory recommendations for preoperative evaluation, intraoperative management, and postoperative care and pain management of WLS patients. We also provided suggestions related to medical error reduction and systems improvements, credentialing, and future research.

DISCUSSION

Obesity-related comorbidities including obstructive sleep apnea place WLS patients at increased risk for complications perioperatively. Regarding perioperative safety and outcomes, conclusive evidence beyond the accepted standard of care in the reviewed literature is limited. Few reports specifically address the perioperative needs of severely obese patients. In this advisory, we synthesize current knowledge and make best practice recommendations for perioperative care and pain management in WLS patients. These recommendations require periodic review as further medical knowledge and evidence evolve.