Preoperative cardiac and pulmonary assessment in bariatric surgery

Obesity Surgery and Anesthesiology Risks: a Review of Key Concepts and Related Physiology

The obesity epidemic is swelling to epic proportions. Obese patients often suffer from a combination of hypertension, dyslipidemia, and type 2 diabetes mellitus (T2DM), also known as the "metabolic syndrome." The metabolic syndrome is an independent predictor of cardiac dysfunction and cardiovascular disease and a risk factor for perioperative morbidity and mortality. In this paper, we discuss the perioperative risk factors and the need for advanced care of obese patients needing general anesthesia for (bariatric) surgical procedures based on physiological principles.

The Amount of Weight Loss Six Months after Bariatric Surgery: It Makes a Difference

BACKGROUND

Bariatric surgery, especially Roux-en-Y gastric bypass (RYGB), has become the most frequently used therapy for morbid obesity.

OBJECTIVES

The aim of this study was to examine the effects of surgically induced weight loss on cardiopulmonary function 6 months after the procedure, as well as the effect of such an intervention on well-known risk factors for cardiovascular diseases.

METHODS

This is a cross-sectional study on 66 morbidly obese patients (BMI ≥40 or ≥35 kg/m2 with present comorbidities), comparing their cardiopulmonary function prior to and 6 months after RYGB surgery.

RESULTS

The substantial amount of weight loss (29.80 ± 13.27 kg) after RYGB surgery was associated with significant reduction of comorbidities, especially diabetes and sedentary lifestyle (p = 0.005 and p = 0.002, respectively). Regarding functional capacity, there was significant increase in peak oxygen uptake (VO2 peak, p = 0.003), duration of exercise testing, metabolic equivalents (exercise time and METs, p < 0.001), and in peak O2 pulse. These findings were particularly pronounced in a group of patients who had lost more than 18% of initial weight.

CONCLUSIONS

Reduction of body weight after RYGB surgery is associated with significantly improved cardiorespiratory function 6 months after surgery, especially in patients who lost more than 18% of their initial body weight. In addition, substantial decreases in body weight were also associated with a reduction of cardiovascular risk factors such as diabetes, smoking, hypertriglyceridemia, and sedentary lifestyle.

A REVIEW OF ECG-BASED DIAGNOSIS SUPPORT SYSTEMS FOR OBSTRUCTIVE SLEEP APNEA

Humans need sleep. It is important for physical and psychological recreation. During sleep our consciousness is suspended or least altered. Hence, our ability to avoid or react to disturbances is reduced. These disturbances can come from external sources or from disorders within the body. Obstructive Sleep Apnea (OSA) is such a disorder. It is caused by obstruction of the upper airways which causes periods where the breathing ceases. In many cases, periods of reduced breathing, known as hypopnea, precede OSA events. The medical background of OSA is well understood, but the traditional diagnosis is expensive, as it requires sophisticated measurements and human interpretation of potentially large amounts of physiological data. Electrocardiogram (ECG) measurements have the potential to reduce the cost of OSA diagnosis by simplifying the measurement process. On the down side, detecting OSA events based on ECG data is a complex task which requires highly skilled practitioners. Computer algorithms can help to detect the subtle signal changes which indicate the presence of a disorder. That approach has the following advantages: computers never tire, processing resources are economical and progress, in the form of better algorithms, can be easily disseminated as updates over the internet. Furthermore, Computer-Aided Diagnosis (CAD) reduces intra- and inter-observer variability. In this review, we adopt and support the position that computer based ECG signal interpretation is able to diagnose OSA with a high degree of accuracy.

Socioeconomic deprivation remains a significant barrier in the choice of bariatric surgery even when full medical expense coverage is present

BACKGROUND

The prevalence of obesity is increasing in the socioeconomically deprived sector of the French population.

OBJECTIVES

Our objective was to assess whether the presence of a socioeconomic gradient could affect access to bariatric surgery in a publicly funded healthcare system with full medical expense coverage.

SETTING

The study was conducted at a general hospital and a health examination center.

METHODS

We prospectively included 100 patients who were admitted to the hospital for a preoperative bariatric surgery evaluation. As a reference group, we included 578 patients from the same area with body mass index (BMI) values≥35 kg/m² who visited the health center for regular medical, cardiovascular checkups. The patients were required to complete the Evaluation of Precariousness and Health Inequalities in Health Examination Centers (EPICES) questionnaire to investigate deprivation (deprivation cutoff≥30.17).

RESULTS

A total of 94 patients had complete data, with a mean EPICES score of 37.7±19.1 (P<.001). Patients were younger (mean age 39.2±12.7 years, P<.001), had a stronger female predominance (87%, P = .030), and higher mean BMI (43.3±6.9 kg/m², P<.001) than the reference group and were less socioeconomically deprived (64% versus 82% in the reference group, P<.001). No significant correlations existed among BMI, participant age, and deprivation score. In a subsequent age- and BMI-matched analysis, bariatric surgery candidates exhibited lower levels of deprivation.

CONCLUSIONS

The presence not only of material (e.g., coverage for medical expenses) but also social support is an important step toward the acceptance of bariatric surgery by morbidly obese patients.

Obesity: physiologic changes and implications for preoperative management

The proportion of patients defined as obese continues to grow in many westernized nations, particularly the United States (USA). This trend has shifted the perioperative management of obese patients into the realm of routine care. As obese patients present for all types of procedures, it is crucial for anesthesiologists, surgeons, internists, and perioperative health care providers alike to have a firm understanding of their altered multi-organ physiology in order to safely prepare the obese patient for an operation. A careful preoperative evaluation may also serve to identify risk factors for postoperative adverse events. Subsequently, preoperative measures may be implemented to mitigate these complications. In this manuscript we address the major considerations for the preoperative evaluation of the severely obese patient.

Preoperative tests recommendations in adult patients for ambulatory surgery

Anesthetic assessment traditionally included a series of laboratory tests intended to detect undiagnosed diseases, and to ensure that the patient undergoes surgery following safety criteria. These tests, without a specific clinical indication, are expensive, of questionable diagnostic value and often useless. In the context of outpatient surgery, recent evidence suggests that patients of any age without significant comorbidity, ASA physical status gradei and grade ii, do not need additional preoperative tests routinely. The aim of the present recommendations is to determine the general indications in which these tests should be performed in ASA gradei and grade ii patients undergoing ambulatory surgery.

Early and long-term clinical outcomes of bilio-intestinal diversion in morbidly obese patients

PURPOSE

To evaluate the early and long-term postoperative results of malabsorptive surgery in morbidly obese patients.

METHODS

Between 2000 and 2007, 102 morbidly obese patients were referred to the Department of Surgery "Pietro Valdoni", "Sapienza" University of Rome, Policlinico "Umberto I°", Rome, Italy for malabsorptive surgery. All patients underwent derivative biliodigestive surgery after they had been reviewed by a team of surgeons, physicians, dieticians, and psychologists.

RESULTS

There were no intra-operative complications, but two patients suffered postoperative pulmonary embolisms, which resolved with medical treatment. The mean postoperative hospital stay was 7 days, with no early or late mortality. Maximum weight loss was reached 12-24 months after surgery, while the mean percentage excess weight loss at 3-5 years ranged from 45 to 64 %. Specific postoperative complications in the first 2 years after surgery were abdominal abscess (n = 2), gastroduodenal reflux (n = 4), and incisional hernia (n = 6). Diabetes resolved in 98 % of the diabetic patients within a few weeks after surgery and blood pressure normalised in 86.4 % of those who had had hypertension preoperatively. Obstructive sleep apnoea and obesity hypoventilation syndrome also improved significantly in 92 % of the patients.

CONCLUSIONS

Morbidly obese patients can undergo biliodigestive surgery safely with good long-term weight loss and quality of life expectancy.

Cross-sectional assessment of the roles of comorbidities in resting and activity-related dyspnea in severely obese women

OBJECTIVES

Obesity has been associated with a lesser degree of asthma control that may be biased by other comorbidities. The objectives of this cross-sectional study were to describe resting and activity-related dyspnea complaints according to the presence of obesity-related comorbidities (asymptomatic airway hyperresponsiveness (AHR), asthma, gastroesophageal reflux disease (GERD) and sleep-disordered breathing (SDB)). We hypothesized that obese women can exhibit both resting and activity-related dyspnea, independently of the presence of asthma.

METHODS

Severely obese (body mass index (BMI) > 35 kg m(-2)) women prospectively underwent description of resting and activity-related dyspnea (verbal descriptors and Medical Research Council (MRC) scale), pulmonary function testing (spirometry, absolute lung volumes, and methacholine challenge test), oesogastro-duodenal fibroscopy, and overnight polygraphy. Thirty healthy lean women without airway hyperresponsiveness were enrolled.

RESULTS

Resting dyspnea complaints were significantly more prevalent in obesity (prevalence 41%) than in healthy lean women (prevalence 3%). Chest tightness and the need for deep inspirations were independently associated with both asthma and GERD while wheezing and cough were related to asthma only in obese women. Activity-related dyspnea was very prevalent (MRC score > 1, 75%), associated with obesity, with the exception of wheezing on exertion due to asthma. Asymptomatic AHR and SDB did not affect dyspneic complaints.

CONCLUSIONS

In severely obese women referred for bariatric surgery, resting dyspnea complaints are observed in association with asthma or GERD, while activity-related dyspnea was mainly related to obesity only. Consequently, asthma does not explain all respiratory complaints of obese women.

Clinical practice guidelines for the perioperative nutritional, metabolic, and nonsurgical support of the bariatric surgery patient--2013 update: cosponsored by American Association of Clinical Endocrinologists, The Obesity Society, and American Society for Metabolic & Bariatric Surgery

The development of these updated guidelines was commissioned by the AACE, TOS, and ASMBS Board of Directors and adheres to the AACE 2010 protocol for standardized production of clinical practice guidelines (CPG). Each recommendation was re-evaluated and updated based on the evidence and subjective factors per protocol. Examples of expanded topics in this update include: the roles of sleeve gastrectomy, bariatric surgery in patients with type-2 diabetes, bariatric surgery for patients with mild obesity, copper deficiency, informed consent, and behavioral issues. There are 74 recommendations (of which 56 are revised and 2 are new) in this 2013 update, compared with 164 original recommendations in 2008. There are 403 citations, of which 33 (8.2%) are EL 1, 131 (32.5%) are EL 2, 170 (42.2%) are EL 3, and 69 (17.1%) are EL 4. There is a relatively high proportion (40.4%) of strong (EL 1 and 2) studies, compared with only 16.5% in the 2008 AACE-TOS-ASMBS CPG. These updated guidelines reflect recent additions to the evidence base. Bariatric surgery remains a safe and effective intervention for select patients with obesity. A team approach to perioperative care is mandatory with special attention to nutritional and metabolic issues.

Clinical practice guidelines for the perioperative nutritional, metabolic, and nonsurgical support of the bariatric surgery patient--2013 update: cosponsored by American Association of Clinical Endocrinologists, the Obesity Society, and American Society for Metabolic & Bariatric Surgery

The development of these updated guidelines was commissioned by the AACE, TOS, and ASMBS Board of Directors and adheres to the AACE 2010 protocol for standardized production of clinical practice guidelines (CPG). Each recommendation was re-evaluated and updated based on the evidence and subjective factors per protocol. Examples of expanded topics in this update include: the roles of sleeve gastrectomy, bariatric surgery in patients with type-2 diabetes, bariatric surgery for patients with mild obesity, copper deficiency, informed consent, and behavioral issues. There are 74 recommendations (of which 56 are revised and 2 are new) in this 2013 update, compared with 164 original recommendations in 2008. There are 403 citations, of which 33 (8.2%) are EL 1, 131 (32.5%) are EL 2, 170 (42.2%) are EL 3, and 69 (17.1%) are EL 4. There is a relatively high proportion (40.4%) of strong (EL 1 and 2) studies, compared with only 16.5% in the 2008 AACE-TOS-ASMBS CPG. These updated guidelines reflect recent additions to the evidence base. Bariatric surgery remains a safe and effective intervention for select patients with obesity. A team approach to perioperative care is mandatory with special attention to nutritional and metabolic issues.

Clinical practice guidelines for the perioperative nutritional, metabolic, and nonsurgical support of the bariatric surgery patient--2013 update: cosponsored by American Association of Clinical Endocrinologists, the Obesity Society, and American Society for Metabolic & Bariatric Surgery

The development of these updated guidelines was commissioned by the AACE, TOS, and ASMBS Board of Directors and adheres to the AACE 2010 protocol for standardized production of clinical practice guidelines (CPG). Each recommendation was re-evaluated and updated based on the evidence and subjective factors per protocol. Examples of expanded topics in this update include: the roles of sleeve gastrectomy, bariatric surgery in patients with type-2 diabetes, bariatric surgery for patients with mild obesity, copper deficiency, informed consent, and behavioral issues. There are 74 recommendations (of which 56 are revised and 2 are new) in this 2013 update, compared with 164 original recommendations in 2008. There are 403 citations, of which 33 (8.2%) are EL 1, 131 (32.5%) are EL 2, 170 (42.2%) are EL 3, and 69 (17.1%) are EL 4. There is a relatively high proportion (40.4%) of strong (EL 1 and 2) studies, compared with only 16.5% in the 2008 AACE-TOS-ASMBS CPG. These updated guidelines reflect recent additions to the evidence base. Bariatric surgery remains a safe and effective intervention for select patients with obesity. A team approach to perioperative care is mandatory with special attention to nutritional and metabolic issues.

Bariatric surgery: the challenges with candidate selection, individualizing treatment and clinical outcomes

Obesity is recognized as a global health crisis. Bariatric surgery offers a treatment that can reduce weight, induce remission of obesity-related diseases, and improve the quality of life. In this article, we outline the different options in bariatric surgery and summarize the recommendations for selecting and assessing potential candidates before proceeding to surgery. We present current data on post-surgical outcomes and evaluate the psychosocial and economic effects of bariatric surgery. Finally, we evaluate the complication rates and present recommendations for post-operative care.

Bariatric surgery: a best practice article

Bariatric surgery can effectively reduce body weight and treat obesity associated metabolic diseases such as diabetes mellitus. There are also benefits for an individual's functional status and psychological health. A multi-disciplinary evaluation should be offered to the individual as the first essential step in considering bariatric surgery as a treatment. This evaluation should include a thorough medical assessment, as well as psychological and dietetic assessments. In this best practice article, we outline the current recommendations for referral for bariatric surgery. We also present the data for pre-operative assessment before bariatric surgery, with particular reference to cardiovascular disease and obstructive sleep apnoea. We describe the literature on outcomes after bariatric surgery, including the results for mortality, weight loss, remission of diabetes and associated endocrine disorders such as hypogonadism. Within this review, we will illustrate the impact of bariatric surgery on self-image, psychological health and perceived health and functional status. Finally, we briefly detail the potential complications of bariatric surgery, and offer advice on post-operative care and surveillance.

Low educational status, smoking, and multidisciplinary team experience predict hospital length of stay after bariatric surgery

Objective:

The objective of the present study was to identify new risk factors associated with longer hospitalization following bariatric surgery.

Methods:

Patient clinical, social, and biochemical data in addition to multidisciplinary team experience were analyzed in a cohort that included all patients undergoing bariatric surgery at our hospital. The primary outcome was length of hospital stay (LOS). Mortality was recorded to validate the obesity surgery mortality risk score (OS-MRS).

Results:

This study included 299 sequential patients, 41 ± 10 years of age, and BMI of 50 ± 8 kg/m² who underwent bariatric surgery. Two thirds (196) of patients were hypertensive, a third (86) were diabetic and a third (91) were current or former smokers. Overall, LOS was 8 ± 5 days. The predictors of a longer LOS were smoking (P < 0.05) and less multidisciplinary team experience (P < 0.05). Looking at only the last three years of data, LOS was 6 ± 5 days, and the predictors of a longer LOS were low educational attainment (P < 0.02) and smoking (P < 0.01) but not team experience. The global mortality was 2.6%, with the OS-MRS identifying a high-risk group.

Conclusion:

Excluding the initial learning phase, longer LOS independent predictors were patient low educational attainment and smoking. These predictors can help guide care to reduce complications.

Prevalence and co-occurrence of upper and lower functional gastrointestinal symptoms in patients eligible for bariatric surgery

BACKGROUND

Obesity is considered as a risk factor for many functional digestive disorders. The aim of the present study was to evaluate the prevalence and the association of functional digestive symptoms affecting the upper and the lower digestive tract in patients eligible for bariatric surgery.

METHODS

Before surgery, 120 consecutive patients with normal upper endoscopy (7.5% males, mean BMI 44 ± 6 m/kg(2)) have filled a standard questionnaire in order to evaluate the presence of depressive symptoms and functional digestive disorders according to the Rome criteria. The major symptoms (esophageal, gastroduodenal, anorectal, and abdominal pain) were coded as dichotomous variables. Data analysis was performed using multivariate logistic regression with a backwards selection procedure adjusted only for the variables that were significant in univariate analysis (p < 0.05).

RESULTS

Functional symptoms were present in 89% of the subjects (2.5 functional digestive symptoms/subject). Depression symptoms were found in 43% of the patients. Esophageal symptoms were independent predictors for the presence of gastric, bowel, and anorectal symptoms. Functional abdominal pain and bowel symptoms were present, respectively, in 19% and 84% of the patients. Approximately half of the patients have specific functional bowel disorders (28.6% constipation, 18% irritable bowel syndrome, 18% diarrhea, 1% bloating) and 35.7% have non-specific bowel disorders. Anorectal symptoms were found in 40% of the patients: difficult defecation in 32% and fecal incontinence in 9.8% of the patients. Depression was an independent predictor for anorectal symptoms.

CONCLUSIONS

This study shows the high prevalence of functional bowel symptoms in patients complaining of morbid obesity.

[Recommendations for the peri-operative management of bariatric surgery patients: results of a national survey]

To standardise possible peri-operative bariatric surgery protocols, a survey was prepared to be filled in by members of the Spanish Society for Obesity (Sociedad Española de Cirugía de la Obesidad) (SECO), and to approve it at the XII National Congress. A total of 47 members of SECO from 14 autonomous communities responded, and it unanimously approved by the Congress. As highly recommended peri-operative procedures, were proposed: full laboratory analysis (98%) with an endocrine study (90%), ECG (96%), chest x-ray (98%), an oesophageal-gastric imaging test (endoscopy or gastro-duodenal transit study (98%), antibiotic prophylaxis (92%) and use of low molecular weight heparins pre-operatively (96%), and for 2 weeks (83%). Pre-surgical, abdominal ultrasound (86%), spirometry (80%), diet (88%) and psychological study (76%), and during surgery, use of elastic stockings (76%), leak tests (92%) and drainages (90%), were established as advisable procedures.

Bariatric surgery

BACKGROUND

Bariatric surgery has increased in numbers, but the treatment of morbid obesity in Germany still needs improvement. The new interdisciplinary S3-guideline provides information on the appropriate indications, procedures, techniques, and follow-up care.

METHODS

Systematic review of the literature, classification of the evidence, graded recommendations, and interdisciplinary consensus-building.

RESULTS

Bariatric surgery is a component of the multimodal treatment of obesity, which consists of multidisciplinary evaluation and diagnosis, conservative and surgical treatments, and lifelong follow-up care. The current guideline extends the BMI-based spectrum of indications that was previously proposed (BMI greater than 40 kg/m(2), or greater than 35 kg/m(2)with secondary diseases) by eliminating age limits, as well as most of the contraindications. A prerequisite for surgery is that a structured, conservative weight-loss program has failed or is considered to be futile. Type 2 diabetes is now considered an independent indication under clinical study conditions for patients whose BMI is less than 35 kg/m(2) (metabolic surgery). The standard laparoscopic techniques are gastric banding, gastric bypass, sleeve gastrectomy, and biliopancreatic diversion. The choice of procedure is based on knowledge of the results, long-term effects, complications, and individual circumstances. Structured lifelong follow-up should be provided and should, in particular, prevent metabolic deficiencies.

CONCLUSION

The guideline contains recommendations based on the scientific evidence and on a consensus of experts from multiple disciplines about the indications for bariatric surgery, the choice of procedure, techniques, and follow-up care. It should be broadly implemented to improve patient care in this field.

Evidence-based German guidelines for surgery for obesity

BACKGROUND

The young field of obesity surgery (bariatric surgery) in Germany expands as a consequence of the rapid increase of overweight and obesity. New surgical methods, minimal access techniques, and the enormous increase of scientific studies and evidence, all contribute to the success of bariatric surgery, which is the only realistic chance of permanent weight loss and regression of secondary diseases in many cases.

METHODS

A systematic literature review, classification of evidence, graded recommendations, and interdisciplinary consensus.

RESULTS

Obesity surgery is an integral component of the multimodal treatment of obesity, which consists of multidisciplinary evaluation and preparation, conservative and surgical treatment elements, and a life-long follow-up. The guideline confirms the body mass index (BMI)-based spectrum of indications (BMI > 40 kg/m(2) or >35 kg/m(2) with secondary diseases) and extends it through elimination of all age restrictions (>18 years and <60 years) and most of the contraindications. Precondition for surgery is the failure of a structured conservative program of 6-12 months or the expected futility of it. Type II diabetes mellitus becomes an independent indication criterion for BMI < 35 kg/m(2) (metabolic surgery). The standard techniques are gastric balloon, gastric banding, gastric bypass, gastric sleeve, and biliopancreatic diversion. The choice of procedure is based on profound knowledge of results, long-term effects, complications, and patient-specific circumstances. The after-care should be structured and organized long term.

CONCLUSION

The S3-guidelines contain evidence-based recommendations for the indication, selection of procedure, technique, and follow-up. Patient care should improve after implementation of these guidelines in clinical practice. Compliance by decision makers and health insurers is warranted.

Dual source CT coronary angiography in severely obese patients: trading off temporal resolution and image noise

OBJECTIVE

To assess in severely obese patients the subjective and objective image quality parameters and to estimate the radiation dose of dual-source computed tomography coronary angiography (CTCA), using 3 different protocols.

MATERIALS AND METHODS

Dual-source CTCA was performed in 60 patients (30 women; mean age 58 +/- 7 years) suffering from obesity class II or higher (body mass index [BMI] >35 kg/sq m). Twenty patients were examined with a standard CTCA protocol at 120 kV/350 mAs (protocol A), 20 patients with a CTCA protocol at 140 kV/350 mAs (protocol B), and 20 patients at 140 kV/350 mAs with a dedicated obesity protocol (protocol C), that allows the additional data sampling by expanding the data acquisition for each tube from a quarter to a half rotation, permitting to trade off temporal resolution and image noise. Two blinded observers independently assessed the image quality of each coronary segment, using a 4-point scale (1: excellent-4: nondiagnostic) and measured the different image parameters (image noise, signal-to-noise ratio [SNR], and contrast-to-noise ratio [CNR]). Radiation dose estimates were calculated.

RESULTS

The average BMI was 46.3 +/- 8.3 kg/sq m (range, 36.8-69.6 kg/sq m). Subjective image quality (1.55 +/- 0.73) was significantly better in protocol C when compared with protocol A (2.46 +/- 0.76; P < 0.01) and protocol B (2.12 +/- 0.87; P < 0.017). There was a significantly lower rate of coronary artery segments with nondiagnostic image quality when using the obesity protocol C (1.5%; 4/262) compared with that obtained when using protocol A (7.8%; 22/280; P < 0.01) and protocol B (4.4%; 12/275; P < 0.017). Image noise was significantly lower in protocol C (31.8 +/- 5.0 HU) when compared with group A (43.5 +/- 4.7 HU; P < 0.001) and B (36.8 +/- 5.5 HU; P < 0.01). SNR and CNR were significantly higher in group C (13.8 +/- 2.4 and 23.1 +/- 2.8) compared with group A (10.6 +/- 1.7 and 15.1 +/- 3.2; each P < 0.001) and group B (12.0 +/- 2.0 and 18.8 +/- 3.1; each P < 0.01). The estimated effective radiation dose of the obesity protocol C (15.6 +/- 0.9 mSv) was significantly higher when compared with that in protocol A (10.1 +/- 0.8 mSv; P < 0.01), but not significantly different from that in protocol B (13.3 +/- 0.8 mSv; P = 0.022).

CONCLUSIONS

Use of an obesity protocol in dual-source CTCA in severely obese patients significantly improves image quality, but goes along with a higher radiation dose.

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.

Current world literature

This bibliography is compiled by clinicians from the journals listed at the end of this publication. It is based on literature entered into our database between 1 February 2008 and 31 January 2009 (articles are generally added to the database about two and a half months after publication). In addition, the bibliography contains every paper annotated by reviewers; these references were obtained from a variety of bibliographic databases and published between the beginning of the review period and the time of going to press. The bibliography has been grouped into topics that relate to the reviews in this issue.

Preoperative screening, evaluation, and optimization of the patient's medical status before outpatient surgery

PURPOSE OF THE REVIEW

Preoperative evaluation and optimization of a patient's medical condition are important components of anesthesia practice. With ever increasing numbers of patients with serious comorbidities having complex procedures as outpatients, the task of gathering information and properly preparing for their care is challenging. Improvements in assessment and management can potentially reduce adverse events, improve patient and caregiver satisfaction, and reduce costs.

RECENT FINDINGS

A growing body of literature and evidence-based practices and guidelines can assist clinicians who work in the expanding field of preoperative medicine. Care providers from various specialties in medicine are developing innovative methods, tools, and knowledge to advance science and processes. Data-driven practices are beginning to close the information gap that has plagued this field of medical practice.

SUMMARY

Preparation of patients before surgery is a necessary and vital component of perioperative medicine. Practices are developing to guide effective interventions that benefit patients and healthcare systems. Outpatients present special challenges to preoperative assessment.