Menoufia Medical Journal

REVIEW ARTICLE
Year
: 2019  |  Volume : 32  |  Issue : 4  |  Page : 1169--1172

Predictors of outcomes in bariatric surgery and anesthesia


Ashraf M Moustafa1, Ayman A Rady1, Hala M Koptan1, Mansour Gamal Shaban Alhanouny2,  
1 Department of Anesthesia, Intensive Care and Pain Management, Faculty of Medicine, Menoufia University, Menoufia, Egypt
2 Department of Anesthesia at Kafrelsheikh General Hospital, Kafrelsheikh, Egypt

Correspondence Address:
Mansour Gamal Shaban Alhanouny
Kafrelsheikh
Egypt

Abstract

Objective The aim of this study was to assess the perioperative and postoperative complications and predictors of outcomes in bariatric surgery and anesthesia. Materials and methods We reviewed papers on the predictors of outcomes in bariatric surgery and anesthesia from Medline databases, which are PubMed, Medscape, Science Direct, and EMF-Portal, and all materials available in the internet up to 2017. The initial search presented articles that studied the predictors of outcomes in bariatric surgery and anesthesia. If the studies did not fulfill the inclusion criteria, they were excluded. Study quality assessment included whether ethical approval was gained, eligibility criteria specified, appropriate controls mentioned, and adequate information provided and assessment measures defined. Significant data were collected. Thus, a structured review was performed. Findings Results showed that bariatric surgery is considered high risk, but careful planning, preoperative risk assessment, adequate anesthetic management, strict venothrombotic event prevention, and effective postoperative pain control will all help to reduce the risk. Conclusion Careful planning, preoperative risk assessment, adequate anesthetic management, strict venothrombotic event prevention, and effective postoperative pain control will all help to improve outcomes and reduce the risk of perioperative mortality.



How to cite this article:
Moustafa AM, Rady AA, Koptan HM, Alhanouny MG. Predictors of outcomes in bariatric surgery and anesthesia.Menoufia Med J 2019;32:1169-1172


How to cite this URL:
Moustafa AM, Rady AA, Koptan HM, Alhanouny MG. Predictors of outcomes in bariatric surgery and anesthesia. Menoufia Med J [serial online] 2019 [cited 2020 Feb 22 ];32:1169-1172
Available from: http://www.mmj.eg.net/text.asp?2019/32/4/1169/274243


Full Text



 Introduction



Obesity represents a significant and growing problem around the globe [1]. Bariatric surgery, which is continuously in development, has been performed to provide weight loss and improved quality of life, as well as to decrease the risk of obesity-related disorders [2]. A wide range of available surgical techniques, including intragastric balloon, biliopancreatic diversion, gastric plication, sleeve gastrectomy, and roux-en-Y anastomosis, have been performed on patients with morbid obesity (BMI >40 kg/m 2) or severe obesity (BMI >35 kg/m 2). Although invasive approaches have been associated with better clinical results, such as consistent weight loss and co-morbidity resolution, their disadvantage is an increased risk of perioperative mortality [3].

Obese patients, undergoing bariatric or other surgical procedures, present an increased anesthetic risk because of physiologic changes, comorbidities, and technical challenges. The implications for anesthetic and perioperative care of these patients are considerable and are believed to escalate in the presence of comorbidities [4].

Obesity has a negative effect on cardiovascular health. The presence of obesity increases the risk of coronary artery disease, heart failure, cardiomyopathy, atrial fibrillation, and hypertension [5].

Bariatric surgery helps patients who have diabetes mellitus and cardiovascular, pulmonary, gastrointestinal, urogenital, orthopedic, and cancer diseases [6].

 Materials and Methods



The guideline for conducting this review according to guidance was developed by the center for review and dissemination. It was used to assess the methodology and outcome of the studies.

We reviewed papers on the outcomes in bariatric surgery and anesthesia from Medline databases, which are PubMed, Medscape, and Science Direct, and also materials available in the internet. We used bariatric surgery and anesthesia as searching terms. In addition, we examined references from the specialist databases EMF-portal (http://www.emf-portal.de) and reference lists in relevant publications. The search was performed in the electronic databases up to 2017.

All the studies were independently assessed for inclusion. They were included if they fulfilled the following criteria:

Published in English languagePublished in peer-reviewed journalsFocused on the outcomes in bariatric surgery and anesthesia.

Data from each eligible study were independently abstracted in duplicate using a data collection form to capture information on study characteristics, interventions, quantitative results reported for each outcome of interest, conclusion and comments on each study made.

There was heterogeneity in the collected data. It was not possible to perform meta-analysis. Significant data were collected. Thus, a structured review was performed with the result tabulated.

The analyzed publications were evaluated according to evidence-based medicine criteria using the classification of the US Preventive Services Task Force and UK National Health Service protocol for evidence-based medicine in addition to the Evidence Pyramid:

Level I: evidence obtained from at least one properly designed randomized controlled trialLevel II-1: evidence obtained from well-designed controlled trials without randomizationLevel II-2: evidence obtained from well-designed cohort or case–control analytic studies, preferably from more than one center or research groupLevel II-3: evidence obtained from multiple time series with or without the intervention. Dramatic results in uncontrolled trials might also be regarded as this type of evidenceLevel III: opinions of respected authorities, based on clinical experience, descriptive studies, or reports of expert committees.

The quality of all the studies was assessed. Important factors included study design, attainment of ethical approval, evidence of a power calculation, specified eligibility criteria, appropriate controls, adequate information, and specified assessment measures. It was expected that confounding factors would be reported and controlled for and appropriate data analysis made in addition to an explanation of missing data.

 Results



Bariatric surgery has been performed to provide weight loss and improve quality of life, as well as to decrease the risk of obesity-related disorders [2]. Its disadvantage is an increased risk of perioperative mortality [3].

Obese patients, undergoing bariatric or other surgical procedures, present an increased anesthetic risk because of physiologic changes, comorbidities, and technical challenges. The implications for anesthetic and perioperative care of these patients are considerable and are believed to escalate in the presence of comorbidities. Surgery in this patient population is considered high risk, but careful planning, preoperative risk assessment, adequate anesthetic management, strict venothrombotic event prevention, and effective postoperative pain control will all help to reduce the risk [4].

 Discussion



Bariatric surgery in the super obese population has positive outcomes of weight loss and medical comorbidities such as diabetes, hypertension, and obstructive sleep apnea (OSA). Preoperative weight loss in bariatric surgery is an important determinant, but weight loss below 10% and over 10% has no superior effect between each other. Staple line bleeding requiring blood transfusion or reoperation can be lowered by decreased pneumoperitoneum pressures intraoperatively [7].

Well-established guidelines regarding preoperative risk stratification have led to improved surgical outcomes. These standards remain useful in the appraisal of an obese patient. There is evidence that obesity itself is a surgical risk factor. Both the predictors of morbidity and mortality after bariatric surgery and the complications of the surgery may be unique to the morbidly obese population, that is, those with a BMI greater than 40.

Understanding the unique requirements of this patient population and providing the appropriate attention to details are vital for minimizing the risk of complications and maximizing the potential for a good start on the long road to weight loss and improved health.

Only a few studies have attempted to define predictors of outcomes in morbidly obese patients for either bariatric or nonbariatric surgery. Early mortality in the bariatric patient has been linked to both preoperative patient characteristics and perioperative complications. Adverse events most common to bariatric surgical patients include pulmonary embolism, pneumonia, anastomotic leaks, marginal ulcers, wound dehiscence, and small bowel obstruction. Lastly, the greater the BMI preoperatively, the more likely that a patient will sustain these poor outcomes.

All comorbid conditions should be evaluated and optimized before these elective procedures. This requires a team approach and adequate communication among the surgical team members and anesthesia providers. Overall, laparoscopic surgery confers definite advantages for the morbidly obese population. Awareness of and preparation for the unique needs and problems of morbidly obese patients undergoing either open or laparoscopic surgery will optimize outcomes and minimize anesthesia-related complications.

The pathophysiological changes associated with obesity include respiratory, cardiovascular, airway, and other systems changes; all are predictors of anesthetic difficulties.

Airway changes include the following: limitation of movement of atlantoaxial joint and cervical spine, excessive tissue folds in the mouth and pharynx, suprasternal, presternal and posterior cervical fat, short thick neck, very thick submental fat pad, and OSA.

Preoperative assessment

Preoperative assessment included the following: stabilizing comorbidities, identifying OSA symptoms, previous surgeries and previous anesthetics, and difficult airway anticipation. Neck circumference of 40 cm equal 5% risk and 60 cm equal 35% risk. BMI per se is not a predictor of a difficult airway.

Preoperative preparation included the following: avoid sedatives, aspiration prophylaxis using proton pump inhibitors (PPIs), H2 antagonists, and thromboembolism prophylaxis.

Intraoperatively, there must be special equipment, trained personnel, and anesthetic expertise.

Positioning was done as follows: special table with a bean bag, cushion gel pads as pressure on gluteal muscles may lead to rhabdomyolysis, and proper positioning.

Induction was done as follows: head-up position, stacking, good preoxygenation, tidal volumes less than 13 ml/kg, positive end expiratory pressure (PEEP), and recruitment maneuvers.

Induction issues were as follows: regurgitation, aspiration, and hypoxemia.

Maintenance was done with sevoflurane and desflurane. N2O was avoided. Fluids were well balanced. Short-acting agents were preferred, considering dexmedetomidine. Profound muscle relaxation is needed using Vecuronium, Rocuronium and Cisatracurium, Pneumoperitoneum was less than 15 mmHg. Opioid-sparing analgesia, NSAIDs and local anesthetics are effective, avoiding high-dose opioid consumption. Multimodal pain control to reduce opioid consumption is associated with shorter length of stay at hospital [8].

Emergence: awaking the patient in a semirecumbent position and FULLY awake (complete reversal of neuromuscular block), Prompt but SAFE (Patient should have return airway reflexes and be breathing with good tidal volumes before tracheal extubation), Observe in OR before transfer. De Baerdemaker and colleagues reported more stable hemodynamics after termination of anesthesia in obese patients after desflurane compared with sevoflurane. Combination of desfluraneurane with remifentanil helps better recovery from anesthesia [9].

In the recovery room, skilled personnel were recruited. Ventilation was observed, and continuous positive airway pressure (CPAP) or bilevel positive airway pressure (BiPAP) was initiated if needed. Multimodal analgesia was used.

Postoperatively

Postoperative management was as follows: thrombophylaxis was initiated, analgesics were continued, CPAP was continued if initiated, antibioprophylaxis was maintained, PPIs were used, gastric protection was done, and fluid management was maintained.

There is no benefit in the routine admittance of patients to the intensive care unit after undergoing bariatric surgery. In international studies, the rates of immediate ICU admission are not exceeding 8% and are justified mainly by risk factors related to old age, BMI greater than 50 kg/m 2 or intraoperative complications [10].

 Conclusion



Obesity is a major healthcare problem that increases comorbidities and decreases the quality of life. It is a daily challenge for the anesthesiologists and needs extra care during the perioperative period. Advancement in the anesthesia technology has made dramatic improvements. The obesity surgery mortality risk score can help both patients and surgical team as well as anesthetists. Best practice requires trained personnel and well-designed equipment. Providing preoxygenation prevents desaturation periods. An optimal anesthetic protocol has not been defined yet. Electrical impedance tomography can help for optimizing ventilation strategies. Bariatric surgery helps both weight loss and comorbidities reduction, especially type 2 diabetes mellitus in the long term [11]. Laparoscopic techniques provide enhanced recovery from surgery. Pregnancy after bariatric surgery appears to effectively reduce the risk of complications such as fetal macrosomia and hypertensive disorders of pregnancy; however, women who become pregnant after bariatric surgery are under risk of having preterm babies [12].

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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