Acute Kidney Injury Following Bariatric Surgery

Background

Postoperative acute kidney injury (AKI) following bariatric surgery has not been well studied. The aim of this study is to identify factors associated with risk of AKI.

Methods

The medical records of adult patients who underwent bariatric surgery between March 1, 2005 and March 31, 2011 at the Mayo Clinic were reviewed to identify patients who experienced AKI, defined as postoperative increase in serum creatinine (sCr) by 0.3 mg/dL within 72 h. For each AKI case, two controls were matched for surgical approach (laparotomy vs. laparoscopic). A chart review was conducted and conditional logistic regression analyses were performed to identify risk factors for AKI.

Results

There were 1,227 patients who underwent bariatric surgery, and of these, 71 developed AKI (5.8 %). The median sCr increase was 0.4 (interquartile range 0.3–0.6) mg/dL. Independent patient factors associated with increased risk included higher body mass index [odds ratio (OR) 1.24, 95 % CI 1.06–1.46 per 5 unit increase, P?=?0.01] and medically treated diabetes mellitus (OR 2.77, 1.36–5.65, P?=?0.01). Patients experiencing AKI had higher rates of blood transfusions (P?<?0.01), postsurgical complications (P?<?0.01), and longer hospital stays (P?<?0.01). Another 30 patients developed kidney injury after 72 postoperative hours, usually in the setting of dehydration.

Conclusions

Kidney injury following bariatric surgery is not uncommon and is associated with higher body mass index and diabetes. Further, there should be a high risk of suspicion for kidney injury in postoperative patients developing volume depletion.     

Perioperative Short-Term Outcome in Super-Super-Obese Patients Undergoing Bariatric Surgery

Background

Prevalence of obesity is increasing with a pandemic magnitude worldwide. Incidence of super-super-obesity (>?60 kg/m²) is expanding by the same means. While bariatric surgery is the only approach with proven long-term results, surgical outcome in super-super-obesity is still discussed controversially.

Objective

This retrospective study examined bariatric surgery patients’ short-term outcome in relation to their degree of obesity.

Setting

Data collection was performed in a German university medical center between March 2010 and November 2013.

Methods

This study analyzes a cohort of 715 patients in a single institution. Patients were subdivided into three groups, obese (≤?49.9 kg/m²), super-obese (≥?50 kg/m²), and super-super-obese (≥?60 kg/m²), and evaluated regarding perioperative outcome.

Results

Three hundred eighty-one patients were included into obese (O); 225 patients, into super-obese (SO); and 109 patients, into super-super-obese (SSO) cohort. There were no significant differences regarding patient characteristics including quantity of comorbidities and perioperative outcome. BMI was significantly lower in patients with complications, compared to patients without complications (p?<?0.05), whereas patients’ age was significantly higher (p?<?0.05) in complication cohort. One SSO patient died of a septic multiorgan failure. Thus, the 30-day overall mortality was 0.14%. The BMI showed an inverse correlation to the patients’ age at surgery (p?<?0.05).

Conclusion

Super-super-obesity should not be considered as a limiting factor for bariatric surgery outcome; however, the patients’ age, surgeries prior to the bariatric procedure, and comorbidities must be considered prior to bariatric surgical treatment.

     

Stroke Volume Variation as a Guide to Fluid Administration in Morbidly Obese Patients Undergoing Laparoscopic Bariatric Surgery

Background  

Perioperative fluid administration in morbidly obese patients is critical. There is scarcity of scientific information in literature on amount and rate of its application. Functional parameters (stroke volume variation (SVV), pulse pressure variation) are considered more accurate predictor of volume status of patients than blood pressure and central venous pressure.     

Diagnostic Value of Ultrasonographic Examination for Nonalcoholic Steatohepatitis in Morbidly Obese Patients Undergoing Laparoscopic Bariatric Surgery

Background There are few data relating to the role of fatty score (FS) and modified fatty score (MFS) in ultrasonographic (US) examination on the diagnosis of nonalcoholic steatohepatitis (NASH) in patients undergoing bariatric surgery. Methods We investigated consecutive patients undergoing laparoscopic bariatric surgery with biopsy-proven nonalcoholic fatty liver disease. Patients with other liver diseases and significant alcohol consumption were excluded. Clinico-demographic and anthropometric data were collected before surgery. Each biopsy specimen was assessed by the same pathologist. Liver US examinations were performed by an independent and experienced sonographer before surgery. FS and MFS, determined by the US scoring system based on degrees of parenchymal echogenicity, far gain attenuation, gallbladder wall blurring, portal vein wall blurring and hepatic vein blurring, were used to assess the severity of fatty liver. US findings were correlated with histologic results. Results Totally 101 patients were enrolled. The mean BMI of the patients was 44.6 ± 5.4 kg/m². 29 patients (29%) were categorized with simple steatosis and 72 (71%) with NASH. FS and MFS were significantly correlated with the histological steatosis, fibrosis and the presence of NASH (P < 0.001). A receiver operating characteristic curve identified the MFS of 2 as the best cut-off point for the prediction of NASH, yielding measures of sensitivity, specificity, positive predictive value, and accuracy for 72%, 86%, 93% and 76%, respectively. The positive likelihood ratio of 5.24 for MFS approximately doubled the post-test probability of NASH from 30% to 70%. Conclusion FS and MFS on US examination exhibit acceptable sensitivity and high specificity for the detection of the presence of NASH in morbidly obese patients and may aid in the selection of patients for closer follow-up or liver biopsy.     

Clinical Predictors of Sleep Apnea in Patients Undergoing Bariatric Surgery

Background: Sleep apnea is a frequent and unappreciated condition of morbidly obese patients. If unrecognized it could lead to significant postoperative complications. A clinical tool to assess the severity of sleep apnea is not available.We prospectively determined whether the Epworth Sleepiness Scale (ESS) or body mass index (BMI) predict the severity of sleep apnea in morbidly obese patients. Methods: 66 consecutive patients evaluated for bariatric surgery from June to November 1999 were examined and prospectively administered a health questionnaire including the ESS. Patients with an ESS ≥ 6 were referred for polysomnography with calculation of Respiratory Disturbance Index (RDI). Sleep apnea was graded as mild (RDI 6-20), moderate (RDI 21-40) and severe (RDI>40). Clinical variables such as BMI and ESS score were compared using regression analysis. Data are mean ± SEM. Results: 4 men and 23 women (27/66) who scored >6 on the ESS completed a sleep study. Mean ESS was 13 ± 4.5. Sleep apnea was mild in 13 patients, moderate in 7, severe in 6, and absent in 1. Mean age was 43 ± 9.5 years. BMI was 52 ± 10 kg/m². Linear regression analysis did not demonstrate correlation between ESS score and severity of sleep apnea (r²=0.03, p>0.05). Multiple regression analysis demonstrated no correlation between BMI, patient snoring, and RDI score. Conclusions: Sleep apnea is frequent in candidates screened for bariatric surgery. ESS is a useful tool to investigate daytime sleepiness and other manifestations of sleep apnea. However, the ESS does not predict the severity of sleep apnea. Clinical suspicion of sleep apnea should prompt polysomnography.     

腹腔镜手术患者围术期不适症状的调查分析

目的 了解腹腔镜手术患者围术期的不适表现及影响因素.方法 采用自行设计的问卷调查50例腹腔镜术后患者的围术期不适症状.结果 腹腔镜手术患者围术期存在的中重度不适主要有:腹部疼痛(42.0%)、咽部不适(56.0%)、拔管后尿频尿痛(46.0%)、术前口渴(34.0%)、术后饥饿(18.0%)和术后口渴(62.0%).结论 腹腔镜手术患者围术期存在不适,可通过改进护理方法和手段,加强康复指导,减轻患者的症状.     

Prevalence and Predictors of Atrial Fibrillation Among Patients Undergoing Bariatric Surgery

Background

While AF is a disease of the elderly, it can occur earlier in the presence of risk factors such as obesity. Bariatric surgery patients are significantly younger and more obese than previously described populations with AF. Therefore, it remains to be determined whether current estimates of the prevalence and predictors for AF remain true in the bariatric surgery population.

Methods

We performed a cross-sectional analysis of 1,341 consecutive patients who underwent bariatric surgery from January 2008 to October 2012. Baseline characteristics were compared between patients with and without AF. For additional comparison, 176 patients with AF and body mass index (BMI) >40 kg/m² were identified from the Vanderbilt AF Registry. A multivariable logistic regression was performed to identify predictors of AF within the bariatric surgery cohort.

Results

The prevalence of AF in the bariatric surgery cohort was 1.9 % (25/1,341). Patients with AF were older (median 56 years (interquartile range [52–64) vs.46 [38–56] years, p?<?0.001), were more often male (48 vs. 23 %, p?=?0.004), had more comorbidities, but had no difference in BMI (50 kg/m² [44–58] vs. 48 [43–54], p?=?0.4). In multivariable analysis, the odds of AF increased 2.2-fold by age per decade (95 % CI, 1.4–3.5; p?<?0.001) and 2.4-fold by male gender (1.1–5.4, p?=?0.03) when adjusted for BMI. BMI was not independently associated with AF (OR 1.15 [95 % CI, 0.98–1.41], p?=?0.09).

Conclusions

The prevalence of AF is 1.9 % among patients undergoing bariatric surgery. Risk of AF was found to increase with age and male gender, but not with higher BMI.     

Non-invasive Evaluation of NAFLD with Indocyanine Green Clearance Test: a Preliminary Study in Morbidly Obese Patients Undergoing Bariatric Surgery

Background

Overweight and obesity dramatically increased in the last years. Hepatic complication of obesity, integrated in the term of non-alcoholic fatty liver disease (NAFLD), is a spectrum of abnormality ranging from steatosis to non-alcoholic steatohepatitis (NASH), potentially leading to cirrhosis. Liver biopsy remains the gold standard to evaluate the stage of NAFLD; however, the procedure is invasive. The indocyanine green (ICG) clearance test is performed since years to assess hepatic function before partial hepatectomy, or after liver transplantation. This study was designed to detect liver complications with the ICG clearance test in a population of obese patients scheduled for bariatric surgery.

Methods

In a prospective cohort study, morbidly obese individuals receiving bariatric surgery with scheduled hepatic biopsies were investigated. Liver function was determined by the ICG test preoperatively, and blood samples were collected. Liver biopsy specimens were obtained for each patient and classified according to the NAFLD activity score (NAS) by a single pathologist that was blinded to the results of the ICG test.

Results

Twenty-six patients were included (7 male and 19 female). The mean age of participants was 45.8 years; the mean body mass index was 41.4 kg/m². According to the NAS, 6 (23.1%) patients revealed manifest NASH, and 5 patients were considered borderline (19.2%). A closed correlation was observed between the ICG clearance test and hepatic steatosis (r = 0.43, p = 0.03), NAS (r = 0.44, p = 0.025), and fibrosis (r = 0.49, p = 0.01).

Conclusions

In obese patients, non-invasive evaluation of liver function with the indocyanine green clearance test correlated with histological features of NAFLD. This may detect non-invasively hepatopathy in obese population and could motive biopsy.

     

Enoxaparin for Thromboprophylaxis in Morbidly Obese Patients Undergoing Bariatric Surgery: Findings of the Prophylaxis Against VTE Outcomes in Bariatric Surgery Patients Receiving Enoxaparin (PROBE) Study

Background: Obese patients undergoing bariatric surgery are at significant risk for venous thromboembolism (VTE). We performed a multicenter, retrospective survey to evaluate the safety and efficacy of enoxaparin for thromboprophylaxis in patients with morbid obesity undergoing primary bariatric surgery. Methods: From January to December 2002, 668 patients who underwent primary bariatric surgery at 5 centers were analyzed retrospectively. Baseline patient demographics, objectively diagnosed cases of VTE, and bleeding events were recorded. Patients received enoxaparin preoperatively (30 mg) or postoperatively (40 mg) every 12 or 24 hours or upon discharge (30 mg every 24 hours for 10 days). Results: Overall, there were 6 (0.9%) pulmonary embolisms (PE) and 1 (0.1%) occurrence of deep vein thrombosis (DVT); all but 1 occurred after the cessation of thromboprophylaxis. The highest incidence of VTE was at Center B, which did not administer perioperative thromboprophylaxis (1 DVT and 2 PEs). There were 6 (0.9%) severe bleeding complications: 3 at center D and 3 at center E. In Center B, 2 deaths were recorded (0.3%): 1 due to sepsis and 1 due to bleeding, with both occurring after thromboprophylaxis was discontinued. Conclusion: The administration of enoxaparin, in various dosing regimens, is safe for thromboprophylaxis in morbidly obese patients undergoing bariatric surgery. Fewer events occurred with perioperative prophylaxis initiated in the hospital. Because all thromboembolic events occurred after the cessation of thromboprophylaxis, extended thromboprophylaxis may be of value.     

Association Between Preoperative Statin Exposure and Acute Kidney Injury in Adult Patients Undergoing Cardiac Surgery

1. Download : Download high-res image (163KB)
2. Download : Download full-size image

     

Bariatric Surgery in Morbidly Obese Patients in Wheelchairs

Two morbidly obese patients are presented. The first patient is a 38-year-old superobese female with BMI 56.2 in a wheelchair secondary to multiple sclerosis. The second patient is a 49-year-old female with BMI 47.7 confined to a wheelchair secondary to spinal cord transection due to a motor vehicle accident. Both patients underwent an open duodenal switch procedure, which provided significant weight loss and improved quality of life primarily for mobility with a wheelchair, as well as controlling comorbidities.     

Drug-Related Problems in Bariatric Surgery: a Retrospective Study

Obesity Surgery - With the rapid increase of bariatric surgery worldwide, drug-related problems (DRPs) in this area seem to be rising. This study aimed to investigate the incidence and...     

Perioperative Risks of Untreated Obstructive Sleep Apnea in the Bariatric Surgery Patient: a Retrospective Study

Background

The use of continuous positive airway pressure (CPAP) perioperatively in bariatric surgery patients with obstructive sleep apnea (OSA) has been controversial. Although studies have demonstrated that CPAP use is safe in bariatric patients, prior studies have not shown improvement in outcomes in these patients.

Methods

A retrospective review of patients who underwent bariatric surgery from 2005 to 2009 was performed. All patients underwent polysomnography preoperatively. Patient age, sex, BMI, comorbidities, polysomnogram data, type of bariatric procedure, length of hospital stay, and postoperative complications were reviewed. The Fisher exact test was used for statistical analysis.

Results

Among the 352 patients studied, 47 with apnea-hypopnea index (AHI) ≥5 did not receive CPAP postoperatively. A total of 7/47 (14.9 %) developed postoperative pulmonary complications. There were no non-pulmonary complications. Some 9/305 (2.95 %) with CPAP developed pulmonary complications. There were 26/305 patients with all-cause complications (8.52 %). The AHI was higher in the group receiving treatment. There was a statistically significant difference in pulmonary complications between patients with and those without treatment (p value 0.0002). The average length of stay was 3.0 and 3.2 days in treatment and comparison groups, respectively, a difference that did not reach statistical significance.

Conclusions

Patients who did not receive CPAP postoperatively developed more pulmonary complications than those with CPAP, suggesting that CPAP might be beneficial in decreasing pulmonary complications in patients undergoing bariatric surgery. However, further investigation is warranted to better delineate other risk factors due to small sample size in our study group.

     

Optimizing Perioperative Care in Bariatric Surgery Patients

Enhanced recovery after surgery (ERAS) programs have been shown to minimise morbidity in other types of surgery, but comparatively less data exist investigating ERAS in bariatric surgery. This article reviews the existing literature to identify interventions which may be included in an ERAS program for bariatric surgery. A narrative literature review was conducted. Search terms included 'bariatric surgery', 'weight loss surgery', 'gastric bypass', 'ERAS', 'enhanced recovery', 'enhanced recovery after surgery', 'fast-track surgery', 'perioperative care', 'postoperative care', 'intraoperative care' and 'preoperative care'. Interventions recovered by the database search, as well as interventions garnered from clinical experience in ERAS, were used as individual search terms. A large volume of evidence exists detailing the role of multiple interventions in perioperative care. However, efficacy and safety for a proportion of these interventions for ERAS in bariatric surgery remain unclear. This review concludes that there is potential to implement ERAS programs in bariatric surgery.