Cardiovascular Evaluation and Management of Severely Obese Patients Undergoing Surgery

Obesity and heart failure: epidemiology, pathophysiology, clinical manifestations, and management

Obesity is a risk factor for heart failure (HF) in both men and women. The mortality risk of overweight and class I and II obese adults with HF is lower than that of normal weight or underweight adults with HF of comparable severity, a phenomenon referred to as the obesity paradox. Severe obesity produces hemodynamic alterations that predispose to changes in cardiac morphology and ventricular function, which may lead to the development of HF. The presence of systemic hypertension, sleep apnea, and hypoventilation, comorbidities that occur commonly with severe obesity, may contribute to HF in such patients. The resultant syndrome is known as obesity cardiomyopathy. Substantial weight loss in severely obese persons is capable of reversing most obesity-related abnormalities of cardiac performance and morphology and improving the clinical manifestations of obesity cardiomyopathy.

Morbid obesity and optimization of preoperative fluid therapy

BACKGROUND

Preoperative venous return (VR) optimization and adequate blood volume is essential in management of morbidly obese patients (MO) in order to avoid perioperative circulatory instability. In this study, all subjects underwent a preoperative 3-week preparation by rapid-weight-loss-diet (RWL) as part of their treatment program for bariatric surgery.

METHODS

This is a prospective, observational study of 34 morbidly obese patients consecutively scheduled for bariatric surgery at Sunderby County Hospital, Luleå, Sweden. Preoperative transthoracic echocardiography (TTE) was performed in the awake state before and after intravascular volume challenge (VC) of 6 ml colloids/kg ideal body weight (IBW). Effects of standardized VC were evaluated by TTE. Dynamic and non-dynamic echocardiographic indices for VC were studied. Volume responsiveness and level of VR before and after VC were assessed by TTE. An increase of stroke volume ≥13% was considered as a volume responder.

RESULTS

Twenty-nine out of 34 patients were volume responders. After VC, a majority of patients (23/34) were euvolemic, and only 2/34 were hypovolemic. Post-VC hypervolemia was observed in 9/34 of patients.

CONCLUSIONS

The IBW-based volume challenge regime was found to be suitable for preoperative rehydration of RWL-prepared MO. Most of the patients were volume responders. Preoperative state of VR was not associated with volume responsiveness. IBW estimates and appropriate monitoring avoids potential hyperhydration in MO. For VC assessment, conventional Doppler indices were found to be more suitable compared to tissue Doppler, giving sufficient information on pressure-volume correlation of the left ventricle in morbidly obese.

Dual implantation of a radio-telemeter and vascular access port allows repeated hemodynamic and pharmacological measures in conscious lean and obese rats

Expansion of physiological knowledge increasingly requires examination of processes in the normal, conscious state. The current study describes a novel approach combining surgical implantation of radio-telemeters with vascular access ports (VAPs) to allow repeated hemodynamic and pharmacological measures in conscious rats. Dual implantation was conducted on 16-week-old male lean and obese Zucker rats. Continued viability one month after surgery was observed in 67% of lean and 44% of obese animals, giving an overall 54% completion rate. Over the five-week measurement period, reliable and reproducible basal mean arterial pressure and heart rate measures were observed. VAP patency and receptor-independent vascular reactivity were confirmed by consistent hemodynamic responses to sodium nitroprusside (6.25 µg/kg). Acutely, minimal hemodynamic responses to repeated bolus administration of 0.2 mL saline indicated no significant effect of increased blood volume or administration stress, making repeated acute measures viable. Similarly, repeated administration of the β-adrenoceptor agonist dobutamine (30 µg/kg) at 10 min intervals resulted in reproducible hemodynamic changes in both lean and obese animals. Therefore, our study demonstrates that this new approach is viable for the acute and chronic assessment of hemodynamic and pharmacological responses in both lean and obese conscious rats. This technique reduces the demand for animal numbers and allows hemodynamic measures with minimal disruption to animals' welfare, while providing reliable and reproducible results over several weeks. In conclusion, dual implantation of a radio-telemeter and VAP introduces a valuable technique for undertaking comprehensive studies involving repeated pharmacological tests in conscious animals to address important physiological questions.

Impact of obesity on mortality and complications in trauma patients

OBJECTIVE

To examine the association between obesity and outcomes in injured patients.

BACKGROUND

The United States is facing an obesity epidemic affecting 1 in 3 adult Americans. Very little is known about the role of obesity in acute illness. Optimal care of obese trauma patients can only be achieved once we gain a better understanding of the impact of severe obesity on trauma outcomes.

METHODS

We conducted a retrospective cohort study of 147,680 patients admitted to 28 level I and level II Pennsylvania trauma centers between 2000 and 2009. Logistic regression was used to examine the association between obesity and in-hospital mortality and major complications, adjusting for injury severity, age, gender, mechanism of injury, systolic blood pressure, and the motor component of the Glasgow Coma Scale, comorbidities, and year of admission. Patients were grouped into predefined weight categories: underweight (<1st percentile), reference (1st-74th percentile), grade 1 obesity (75th-90th percentile), grade 2 obesity (91th-95th percentile), grade 3 obesity (96th-99th percentile), and grade 4 obesity (>99th percentile). Body mass index was not calculated because height data was not available.

RESULTS

After adjusting for injury severity and other risk factors, male patients with severe obesity-grade 3 obesity [adjusted odds ratio (AOR) 1.28; 95% confidence interval (CI): 1.00, 1.64; P = 0.052] or grade 4 obesity (AOR 2.30; 95% CI: 1.48, 3.58; P < 0.001)-were more likely to die than nonobese patients. Severe obesity was associated with an approximately twofold higher risk of major complications: male patients with grade 3 obesity (AOR 1.71; 95% CI: 1.48, 1.97; P < 0. 001) or grade 4 obesity (AOR 2.14; 95% CI: 1.83, 2.51; P < 0.001). Similar results were obtained for female patients. Male and female patients with severe obesity had a 2.5- to 4-fold higher risk of developing acute renal failure. Severely obese females had 2.5- to 4.5-fold higher risk of developing wound complications, and a 4-to 8-fold higher risk of developing decubiti.

CONCLUSIONS

Severely obese trauma patients were at least 30% more likely to die and approximately twice as likely to have a major complication compared with nonobese patients.

Risk factors associated with mortality after Roux-en-Y gastric bypass surgery

OBJECTIVE

We sought to identify the major risk factors associated with mortality in Roux-en-Y gastric bypass (RYGB) surgery.

BACKGROUND

Bariatric surgery has become an established treatment for extreme obesity. Bariatric surgery mortality has steadily declined with current rates of less than 0.5%. However, significant variation in the mortality rates has been reported for specific patient cohorts and among bariatric centers.

METHODS

Clinical outcome data from 185,315 bariatric surgery patients from the Bariatric Outcome Longitudinal Database were reviewed. Of these, 157,559 patients had either documented 30 or more day follow-up data, including mortality. Multiple demographic, socioeconomic, and clinical factors were analyzed by univariate analysis for their association with 30-day mortality after gastric bypass. Variables found to be significant were entered into a multiple logistic regression model to identify factors independently associated with 30-day mortality. On the basis of these results, a RYGB mortality risk score was developed.

RESULTS

The overall 30-day mortality rate for the entire bariatric surgery cohort was 0.1%. Of the 81,751 RYGB patients, the mortality rate was 0.15%. Factors significantly associated with 30-day gastric bypass mortality included increasing body mass index (BMI) (P<0.0001), increasing age (P<0.005), male gender (P<0.001), pulmonary hypertension (P<0.0001), congestive heart failure (P=0.0008), and liver disease (P=0.038). When the RYGB risk score was applied, a significant trend (P<0.0001) between increasing risk score and mortality rate is found.

CONCLUSIONS

Increasing BMI, increasing age, male gender, pulmonary hypertension, congestive heart failure, and liver disease are risk factors for 30-day mortality after RYGB. The RYGB risk score can be used to determine patients at greater risk for mortality after RYGB surgery.

Severe obesity, heart disease, and death among white, African American, and Hispanic postmenopausal women

OBJECTIVE

To compare mortality, nonfatal coronary heart disease (CHD), and congestive heart failure (CHF) risk across BMI categories in white, African American, and Hispanic women, with a focus on severe obesity (BMI ≥ 40), and examine heterogeneity in weight-related CHD risk.

METHODS

Among 156,775 Women's Health Initiative observational study and clinical trial participants (September 1993-12 September 2005), multivariable Cox models estimated relative risk for mortality, CHD, and CHF. CHD incidence was calculated by anthropometry, race, and cardiovascular risk factors (CVRF).

RESULTS

Mortality, nonfatal CHD, and CHF incidence generally rose with BMI category. For severe obesity versus normal BMI, hazard ratios (HRs, 95% confidence interval) for mortality were 1.97 (1.77-2.20) in white, 1.55 (1.20-2.00) in African American, and 2.59 (1.55-4.31) in Hispanic women; for CHD, HRs were 2.05 (1.80-2.35), 2.24 (1.57-3.19), and 2.95 (1.60-5.41) respectively; for CHF, HRs were 5.01 (4.33-5.80), 3.60 (2.30-5.62), and 6.05 (2.49-14.69). CVRF variation resulted in substantial variation in CHD rates across BMI categories, even in severe obesity. CHD incidence was similar by race/ethnicity when differences in BMI or CVRF were accounted for.

CONCLUSIONS

Severe obesity increases mortality, nonfatal CHD, and CHF risk in women of diverse race/ethnicity. CVRF heterogeneity contributes to variation in CHD incidence even in severe obesity.

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.

Changes in predicted cardiovascular disease risk after biliopancreatic diversion surgery in severely obese patients

OBJECTIVE

To determine the impact of biliopancreatic diversion with duodenal switch (BPD-DS) surgery on cardiovascular risk profile and predicted cardiovascular risk in severely obese patients.

MATERIALS/METHODS

We compared 1-year follow-up anthropometric and metabolic profiles in severely obese who underwent BPD-DS (n = 73) with controls (severely obese without surgery) (n =3 3). The 10-year predicted risk for coronary heart disease (CHD) was estimated using the Framingham risk-tool. We assigned 10-year and lifetime predicted risks to stratify subjects into 3 groups: 1) high short-term predicted risk (≥ 10% 10-year risk or diagnosed diabetes), 2) low short-term (<10% 10-year risk)/low lifetime predicted risk or 3) low short-term/high lifetime predicted risk.

RESULTS

During the follow-up period, body weight and body mass index decreased markedly in the surgical group (-52.1 ± 1.9 kg and -19.0 ± 0.6 kg/m(2) respectively, p<0.001) vs. (-0.7 ± 1.0 kg and -0.3 ± 0.4 kg/m(2), p = 0.51). Weight loss in the surgical group was associated with a reduction in HbA1C (6.2% vs. 5.1%), HOMA-IR (61.5 vs. 9.3), all lipoprotein levels, as well as blood pressure (p<0.001). The 10-year CHD predicted risk decreased by 43% in women and 33% in men, whereas the estimated CHD risk in the non surgical group did not change. Before surgery, none of the women and only 18% of men showed low short-term/low lifetime predicted risk, whereas a significant proportion of subjects had high short-term predicted risk (36% in women and 12% in men). Following surgery, 52% of women and 55% of men have a low short-term/low lifetime predicted risk.

CONCLUSIONS

These results highlight the cardiovascular benefits of BPD-DS and suggest a positive impact on predicted CHD risk in severely obese patients. Long-term studies are needed to confirm our results and to ascertain the effects on CHD risk estimates after BPD-DS surgery.

Feasibility and prognostic value of stress echocardiography in obese, morbidly obese, and super obese patients referred for bariatric surgery

BACKGROUND

Stress echocardiography (SE) is clinically used in the risk stratification and prognosis of patients with coronary artery disease. Due to multiple comorbidities, obese patients have increased risk of adverse cardiovascular events perioperatively in noncardiac surgery. The aim of this study was to investigate the feasibility of SE in morbidly obese patients undergoing bariatric surgery.

METHODS

Consecutive patients referred for SE for preoperative evaluation prior to bariatric surgery from January 2002 to July 2011 formed the study cohort. Contrast was used to define the endocardial border in patients with poor acoustic windows. All-cause mortality data were obtained from Social Security Death Index.

RESULTS

Six hundred fifty-two patients (47 ± 10 years, 84% females) with the mean follow-up of 3.0 ± 2.7 years and mean body mass index (BMI) of 47 ± 9 kg/m² were included in this analysis. Dobutamine SE was performed in 65% of patients compared to exercise SE in 35%. Patients with higher BMI were more likely to undergo dobutamine SE (P < 0.0001). Similarly, incidence of poor acoustic windows and contrast use was higher in those with increased BMI (P < 0.001). Contrast use was higher in patients undergoing dobutamine SE (39%) versus exercise (25%), (P = 0.002). 19 patients (3%) had an abnormal SE and 8 patients (1.2%) died during the follow-up period.

CONCLUSION

Stress echocardiography is feasible in the morbidly obese patients. Patients with higher BMI were more likely to undergo dobutamine SE and have higher incidence of poor acoustic windows and contrast use.

Blood pressure assessment in severe obesity: validation of a forearm approach

OBJECTIVE

Obesity is frequently associated with systemic hypertension. Blood pressure measure is inaccurate in severely obese patients because of poor cuff size fitting. The aim of the study is to assess the degree of agreement between the intra-arterial method as the gold standard vs. noninvasive methods, i.e., forearm blood pressure and upper-arm blood pressure measures.

DESIGN AND METHODS

A total of 1285 measures of intra-arterial and forearm blood pressure were taken in 51 severely obese patients in a supine position in the operating and the recovery room. A subset of 352 upper-arm measures were taken in the recovery room and compared to the intra-arterial and the forearm methods.

RESULTS

Correlation between the intra-arterial and the forearm measures was 0.90 (P < 0.001) for the 2570 data (systolic and diastolic). Compared to intra-arterial, the forearm method overestimated systolic (6 ± 16 mm Hg, P < 0.001) and underestimated diastolic blood pressure (2 ± 11 mm Hg, P = 0.03). Compared to intra-arterial, upper-arm underestimated systolic (8 ± 16 mm Hg, P < 0.01) and overestimated diastolic blood pressure (9 ± 7 mm Hg, P < 0.001).

CONCLUSION

The magnitude of differences between the intra-arterial and forearm method was less than differences between the intra-arterial and upper-arm method. Our results suggest that forearm method may be a more accurate alternative to upper-arm measurement to assess blood pressure in severely obese patients.

Padrões alimentares e imagem corporal em mulheres frequentadoras de academia de atividade física

Objetivou-se avaliar os padrões alimentares, de atividade física e o grau de insatisfação com a imagem corporal em mulheres frequentadoras de academia de atividade física. 30 mulheres participaram do estudo. Os instrumentos utilizados foram: Teste de Atitudes Alimentares (EAT-26), Teste de Investigação Bulímica de Edimburgo (BITE), Questionário de Imagem Corporal (BSQ), Inventário de Sentimentos sobre Atividade Física (ISAF) e Índice de Massa Corporal (IMC). Quanto aos resultados, 40% das participantes apresentavam alteração no IMC, 9,9% apresentaram comportamento de risco para o desenvolvimento de transtorno alimentar, 57,7% apresentaram alguma distorção na imagem corporal e 30% mostraram atitude positiva com relação à prática de atividade física. Mulheres na faixa de 26 a 33 anos apresentaram mais atitudes alimentares patológicas do que as demais. Sugere-se a realização de estudos complementares com foco nas práticas de promoção da saúde envolvendo frequentadoras de academia de atividade física.

Effect of body mass index on early clinical outcomes after cardiac surgery

Background

there are several reports on the outcomes of cardiac surgery in relation to body mass index. Some concluded that obesity did not increase morbidity or mortality after cardiac surgery, whereas others demonstrated that obesity was a predictor of both morbidity and mortality.

Methods

this was a retrospective study of 3370 adult patients undergoing cardiac surgery. The patients were divided into 4 groups according to body mass index. The 4 groups were compared in terms of preoperative, operative, and postoperative characteristics.

Results

obese patients had a significantly younger mean age. Diabetes, hypertension, and hyperlipidemia were significantly more common in obese patients. The crossclamp time was significantly longer in the underweight group. Reoperation for bleeding, and pulmonary, gastrointestinal, and renal complications were significantly more common in the underweight group. Wound complications were significantly more frequent in the obese group. Mortality was inversely proportional to body mass index. The adjusted odds ratios of the early clinical outcomes demonstrated a higher risk of wound complications in overweight and obese patients

Conclusion

body mass index has no effect on early clinical outcomes after cardiac surgery, except for a higher risk of wound complications in overweight and obese patients.

Overview of epidemiology and contribution of obesity to cardiovascular disease

The prevalence of obesity has increased worldwide and is a source of concern since the negative consequences of obesity start as early as in childhood. The most commonly used anthropometric tool to assess relative weight and classify obesity is the body mass index (BMI); BMI alone shows a U- or a J-shaped association with clinical outcomes and mortality. Such an inverse relationship fuels a controversy in the literature, named the 'obesity paradox', which associates better survival and fewer cardiovascular (CV) events in patients with elevated BMI afflicted with chronic diseases compared to non-obese patients. However, BMI cannot make the distinction between an elevated body weight due to high levels of lean vs. fat body mass. Generally, an excess of body fat (BF) is more frequently associated with metabolic abnormalities than a high level of lean body mass. Another explanation for the paradox is the absence of control for major individual differences in regional BF distribution. Adipose tissue is now considered as a key organ regarding the fate of excess dietary lipids, which may determine whether or not body homeostasis will be maintained (metabolically healthy obesity) or a state of inflammation/insulin resistance will be produced, with deleterious CV consequences. Obesity, particularly visceral obesity, also induces a variety of structural adaptations/alterations in CV structure/function. Adipose tissue can now be considered as an endocrine organ orchestrating crucial interactions with vital organs and tissues such as the brain, the liver, the skeletal muscle, the heart and blood vessels themselves. Thus, the evidence reviewed in this paper suggests that adipose tissue quality/function is as important, if not more so, than its amount in determining the overall health and CV risks of overweight/obesity.

Rapid weight loss is associated with preoperative hypovolemia in morbidly obese patients

BACKGROUND

In morbidly obese patients (MO), adequate levels of venous return (VR) and left ventricular filling pressures (LVFP) are crucial in order to augment perioperative safety. Rapid weight loss (RWL) preparation with very low calorie diet is commonly used aiming to facilitate bariatric surgery. However, the impact of RWL on VR and LVFP is poorly studied.

METHODS

In this prospective, controlled, single-center study, we hypothesized that RWL-prepared MO prior to bariatric surgery can be hypovolemic (i.e., low VR) and compared MO to lean controls with conventional overnight fasting. Twenty-eight morbidly obese patients were scheduled consecutively for bariatric surgery and 19 lean individuals (control group, CG) for elective general surgery. Preoperative assessment of VR, LVFP, and biventricular heart function was performed by a transthoracic echocardiography (TTE) protocol to all patients in the awake state. Assessment of VR and LVFP was made by inferior vena cava maximal diameter (IVCmax) and inferior vena cava collapsibility index- (IVCCI) derived right atrial pressure estimations.

RESULTS

A majority of MO (71.4 %) were hypovolemic vs. 15.8 % of lean controls (p < 0.001, odds ratio = 13.3). IVCmax was shorter in MO than in CG (p < 0.001). IVCCI was higher in MO (62.1 ± 23 %) vs. controls (42.6 ± 20.8; p < 0.001). Even left atrium anterior-posterior diameter was shorter in MO compared to CG.

CONCLUSIONS

Preoperative RWL may induce hypovolemia in morbidly obese patients. Hypovolemia in MO was more common vs. lean controls. TTE is a rapid and feasible tool for assessment of preload even in morbid obesity.

Severe obesity in children and adolescents: identification, associated health risks, and treatment approaches: a scientific statement from the American Heart Association

Severe obesity afflicts between 4% and 6% of all youth in the United States, and the prevalence is increasing. Despite the serious immediate and long-term cardiovascular, metabolic, and other health consequences of severe pediatric obesity, current treatments are limited in effectiveness and lack widespread availability. Lifestyle modification/behavior-based treatment interventions in youth with severe obesity have demonstrated modest improvement in body mass index status, but participants have generally remained severely obese and often regained weight after the conclusion of the treatment programs. The role of medical management is minimal, because only 1 medication is currently approved for the treatment of obesity in adolescents. Bariatric surgery has generally been effective in reducing body mass index and improving cardiovascular and metabolic risk factors; however, reports of long-term outcomes are few, many youth with severe obesity do not qualify for surgery, and access is limited by lack of insurance coverage. To begin to address these challenges, the purposes of this scientific statement are to (1) provide justification for and recommend a standardized definition of severe obesity in children and adolescents; (2) raise awareness of this serious and growing problem by summarizing the current literature in this area in terms of the epidemiology and trends, associated health risks (immediate and long-term), and challenges and shortcomings of currently available treatment options; and (3) highlight areas in need of future research. Innovative behavior-based treatment, minimally invasive procedures, and medications currently under development all need to be evaluated for their efficacy and safety in this group of patients with high medical and psychosocial risks.

Delayed efficient anticoagulation with heparin in patients with a weight of 110 kg and more treated for acute coronary syndrome

OBJECTIVE

The use of a weight-based nomogram is considered as standard care for prescribing appropriate doses of unfractionated heparin (UFH). Because of the need for multiple other medications that may affect bleeding and that clinical data have relied on similar dosing algorithms, maximum initial bolus and infusion rates have been suggested (capped initial dose). Whether these weight-based heparin nomograms properly address therapeutic dosing in obese patients remains questionable.

DESIGN AND METHODS

Thirty patients treated for acute coronary syndrome and weighing ≥110 kg were retrospectively compared with 90 controls (three groups of 30 patients, weighting 50-69.9, 70-89.9, or 90-109.9 kg), all treated with UFH, July 2008 to April 2009. The primary end point was the time required to obtain a threshold activated partial thromboplastin time (aPTT).

RESULTS

Mean time to achieve threshold aPTT was longer for obese patients weighing ≥110 kg than for controls (31.47 vs. 12.89 hours; P < 0.0001). At 24 hours, 63% of obese patients weighing ≥110 kg had not reached threshold aPTT vs. 7% of controls (P < 0.0001). However, threshold infusion rate did not differ between weight categories (13.0 vs. 13.1 U/kg/h; P = NS) and approximated the initial infusion rate recommended by nomograms without applying the dose cap (12 U/kg/h).

CONCLUSIONS

Adequate anticoagulation time doubled in patients weighing ≥110 kg, suggesting that these patients were not receiving appropriate heparin doses initially to achieve threshold aPTT rapidly. Using initial infusion rate recommended by a nomogram without capping for total body weight is suggested as acceptable in this study. This approach should be further evaluated in a prospective study.

Obesity in anesthesia and intensive care

Obesity is a global epidemic increasingly affecting management of anesthesia as well as intensive care medicine. Possible improvements in therapy require consideration of the specific pathophysiology of the obese, their concomitant diseases, and the complications associated with morbid obesity. Systematic assessment of perioperative risk factors is essential for an appropriate management. Paradoxically, overweight and moderately obese patients undergoing surgery have a lower risk when compared to patients with normal weight. The highest mortality and morbidity rates in this setting are reported for underweight and morbidly obese patients. The better chance of survival when compared to normal-weight individuals in the perioperative setting has been described the obesity paradox. In particular, the commitment of all involved physicians to improve all aspects of care will reduce the perioperative risk in obese patients. Physiological and pharmacological characteristics of the obese should also be considered. Furthermore, adequate technical equipment and practical skills of all members of the anesthesia team significantly contribute to risk reduction and therapeutic success in obese patients.

Total knee arthroplasty in morbidly obese patients treated with bariatric surgery: a comparative study

Our objective was to compare outcomes (anesthesia time, total operative time, tourniquet time, duration of hospital stay, 90-day complication rate, and transfusion rates) of patients with total knee arthroplasty (TKA) who underwent bariatric surgery before or after TKA. One hundred twenty-five patients were included: TKA before bariatric surgery (group 1; n = 39), TKA within 2 years of bariatric surgery (group 2; n = 25), and TKA more than 2 years after bariatric surgery (group 3; n = 61). Patients with TKA more than 2 years after bariatric surgery had shorter anesthesia and total operative and tourniquet times than other groups; differences were significant between groups. Ninety-day complication and transfusion rates approached but did not meet statistical significance. Ninety-day complication rates and duration of hospital stay did not differ significantly between the 3 groups. The level of evidence was level II (cohort study).