The impact of duration and severity of obesity exposure on cardiometabolic health

PURPOSE

Duration and severity of exposure to excess adipose tissue are important risk factors for complications, but are generally not examined in conjunction. We developed a metric considering both factors to examine the relationship between obesity-related complications and parameters of cardiometabolic health in patients undergoing a metabolic bariatric procedure (MBS).

MATERIALS & METHODS

Data from patients screened for primary MBS between 2017 and 2021 were analyzed. The Obesity Exposure score (OBES), based on self-reported years of life with a BMI ≥ 25 kg/m2, was calculated with increased weighting applied for higher BMI categories. Multivariate logistic regression analysis was performed, adjusting for multiple potential confounders.

RESULTS

In total, 2441 patients were included (76% female, age 42.1 ± 11.9 years, BMI 42.0 ± 4.9 kg/m2). OBES was positively related to myocardial infarction, atrial fibrillation and renal function loss (per 10 OBES-units: OR 1.31, 95%CI [1.11-1.52], p = 0.002; OR 1.23, 95% CI [1.06-1.44], p = 0.008; and OR 1.26, 95% CI [1.04-1.51], p = 0.02). OBES was negatively associated with obstructive sleep apnea syndrome (OSAS) (OR 0.90, 95% CI [0.83-0.98], p = 0.02). In patients without obesity-related complications, OBES was related to lower HbA1c and higher HDL-cholesterol levels (ß -0.5 95% CI [-0.08-.0.02] p < 0.001 and ß 0.02 [0.00-0.04] p = 0.01).

CONCLUSION

OBES was related to myocardial infarction, atrial fibrillation and renal function loss in patients applying for MBS. OBES was negatively related to OSAS, possibly because undiagnosed years were not taken into account. In the absence of obesity-related complications, OBES was not related to metabolic blood markers. Our data may aid in improving perioperative risk assessments.

Robotic-assisted surgery in high-risk surgical patients with endometrial cancer

Many patients diagnosed with an endometrial cancer are at high-risk for surgery due to factors such as advanced age, raised body mass index or frailty. Minimally-invasive surgery, in particular robotic-assisted, is increasingly used in the surgical management of endometrial cancer however, there are a lack of clinical trials investigating outcomes in high-risk patient populations. This article will review the current evidence and identify areas of uncertainty where future research is needed.

Anaesthetic nurse specialist role in perioperative anaesthetic management of patients who are morbidly obese

This integrative literature review examined the role of an anaesthetic nurse specialist (ANS) in the perioperative anaesthetic nursing management of morbidly obese patients associated with elective orthopaedic surgery. The responsibility of the ANS is to provide high-quality perioperative anaesthetic care to ensure patient safety. Morbid obesity is increasing globally, with significant implications for healthcare delivery, care and treatment, including perioperative care. The Association of Anaesthetists of Great Britain and Ireland emphasises that the perioperative management of these patients presents significant organisational and practical issues. However, there are limited data or guidelines on whether surgeons, anaesthetists and nurses routinely take special precautions in managing morbidly obesity patients undergoing elective orthopaedic operative procedures. The authors carried out a search of databases, followed by an integrated literature review and synthesis of 11 studies. The main findings revealed significant clinical challenges and resource requirements for perioperative anaesthetic management of this patient group. Recommendations are made to prepare for and manage these surgical patients, from preoperative assessment to postoperative care.

The Impact of Body Mass Index on Local Anaesthetic Inguinal Hernia Repair

BACKGROUND

Open mesh repair of inguinal hernia is acceptable and can be performed under local anaesthesia (LA). Individuals with high BMI (Body Mass Index) have often been excluded from LA repairs for varying reasons including safety concerns. Open repair of unilateral inguinal hernia (UIH) amongst individuals with different BMI groups was studied. Its safety profile was investigated using LA volume and length of operation (LO) as endpoints. Operative pain and patient satisfaction were also evaluated.

PATIENTS AND METHODS

A total of 438 adult patients were studied having excluded underweight patients, those requiring any additional intra-operative analgesia, multiple procedures, or records with incomplete data. Operative pain, patient satisfaction, LO and LA volume were retrospectively studied from the existing data from clinical and operative notes.

RESULTS

It was a predominantly male population (93.2% males) with an age range of 17-94 years peaking in the 60-69 years age group. BMI ranged 19-39 kg/m² with BMI above normal at 62.8%. LO was 13-100 minutes (average 37 mins {SD = 12}) utilising an average LA volume of 45 ml (SD = 11) per patient. Across BMI groups, no significant difference in LO (P = 0.168) or patient satisfaction (P = 0.388) was seen. Although LA volume (P = 0.011) and pain score (P<0.001) demonstrated statistically significant differences, these did not appear to be clinically relevant. Over 90% in each BMI group experienced mild or no pain and with severe pain reported in only one patient in the entire population. Overall, LA volume required per patient was low and dosage was safe in all BMI groups with significant proportion (89%) of patients evaluated for satisfaction rating their experience ≥ 90 out of 100.

CONCLUSION

LA repair is safe and well tolerated irrespective of BMI. BMI is not a viable reason for exclusion of obese/overweight individuals from LA repair.

High-Flow Nasal Cannula for Apneic Oxygenation in Obese Patients for Elective Surgery: A Systematic Review and Meta-Analysis

BACKGROUND

Obese patients desaturate rapidly during the apneic period after induction of anesthesia for elective surgery. Administration of oxygen using high-flow nasal cannulae (HFNCs) may prevent desaturation in nonobese patients compared to facemask (FM) preoxygenation. The aim of this meta-analysis was to compare the effectiveness of HFNC to FM preoxygenation techniques in reducing preintubation desaturation in obese patients undergoing elective surgery.

METHODS

This study protocol was registered on PROSPERO (CRD42022309391). Adult studies that compared HFNC and FM preoxygenation in obese patients requiring general anesthesia for elective surgery were included. The primary outcome was desaturation resulting in oxygen saturation of <92% from induction of anesthesia until intubation. Secondary outcomes included the lowest arterial oxygen content before intubation expressed in mm Hg, safe apnea time expressed in seconds, the lowest oxygen saturation before intubation expressed as a percentage, patient-reported discomfort, the need for rescue ventilation, and the incidence of aspiration of gastric contents during intubation. Risk of bias was assessed using the Cochrane Collaboration tool. Certainty was assessed following the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach.

RESULTS

Six studies including 351 participants were eligible for analysis. There was no difference in odds of oxygen desaturation <92% between HFNC and FM (odds ratio [OR], 0.49; 95% confidence interval [CI], 0.15-1.63; P = .24). The HFNC group had a significantly longer safe apnea time (mean difference [MD], -124.20 with 95% CI, -200.47 to -47.93; P = .001). There was no difference between HFNC and FM in the lowest arterial oxygen content (MD, -23.90; 95% CI, -88.64 to 40.85; P = .47) and the lowest peripheral oxygenation saturation (MD, -0.47 with 95% CI, -5.07 to 4.12; P = .84). HFNC had a lower odd of discomfort than FM (OR, 0.13; 95% CI, 0.03-0.52; P = .004). There was no difference in the odds of aspiration of gastric contents between HFNC and FM (OR, 0.33; 95% CI, 0.01-8.21; P = .50). The risk of bias for our primary and secondary outcomes was low. The GRADE assessment for our primary outcome indicated a low level of certainty. For secondary outcomes, the GRADE assessment indicated a very low certainty for all outcomes except for patient discomfort, which was indicated as a moderate level of certainty.

CONCLUSIONS

There may be no difference between HFNC and FM preoxygenation in preventing oxygen desaturation <92% or the lowest oxygen saturation before intubation. Preparation remains important to prevent and manage desaturation during induction of obese patients.

A Comparison of Oxygenation Efficacy between High-Flow Nasal Cannulas and Standard Facemasks during Elective Tracheal Intubation for Patients with Obesity: A Randomized Controlled Trial

Obese patients are predisposed to rapid oxygen desaturation during tracheal intubation. We aimed to compare the risk of desaturation between high-flow nasal oxygenation (HFNO) and classical facemask oxygenation (FMO) during rapid sequence intubation for elective surgery in obese patients. Adults with a body mass index ≥30 kg·m−2 undergoing laparoscopic sleeve gastrectomy at a medical center were randomized into the HFNO group (n = 40) and FMO group (n = 40). In the HFNO group, patients used a high-flow nasal cannula to receive 30 to 50 L·min−1 flow of heated and humidified 100% oxygen. In the FMO group, patients received a fitting facemask with 15 L·min−1 flow of 100% oxygen. After 5-min preoxygenation, rapid sequence intubation was performed. The primary outcome was arterial desaturation during intubation, defined as a peripheral capillary oxygen saturation (SpO2) <92%. The risk of peri-intubation desaturation was significantly lower in the HFNO group compared to the FMO group; absolute risk reduction: 0.20 (95% confidence interval: 0.05−0.35, p = 0.0122); number needed to treat: 5. The lowest SpO2 during intubation was significantly increased by HFNO (median 99%, interquartile range: 97−100) compared to FMO (96, 92−100, p = 0.0150). HFNO achieved a higher partial pressure of arterial oxygen (PaO2) compared to FMO, with medians of 476 mmHg (interquartile range: 390−541) and 397 (351−456, p = 0.0010), respectively. There was no difference in patients’ comfort level between groups. Compared with standard FMO, HFNO with apneic oxygenation reduced arterial desaturation during tracheal intubation and enhanced PaO2 among patients with obesity.

Integrating ultrasound with the combined spinal-epidural kit as a rescue technique during difficult spinal anaesthesia

Conducting spinal anaesthesia in patients with elevated body mass index is commonly difficult, yet there are no guidelines to direct best practice. Landmark techniques are sometimes insufficient, leading to increased failure rates and suboptimal patient outcomes. Although ultrasound-guided techniques are now considered standard care for central venous access and regional anaesthesia, there has been relatively sparse uptake of this widely available resource for central neuraxial block, despite evidence of its efficacy.

This article outlines a successful case of ultrasound-assisted spinal anaesthesia, after landmark techniques failed, in conjunction with a combined spinal-epidural kit. This unique combination of techniques has not been published as an amalgamated rescue strategy for difficult spinal anaesthesia. This article adds to current evidence by highlighting the potential benefits of combining these techniques into a novel approach either when difficulties are expected or as a rescue technique after failed landmark-based attempts.

The Relationship Between Body Mass Index and In-Hospital Mortality in Patients Following Coronary Artery Bypass Grafting Surgery

Background: The association between Body Mass Index (BMI) and clinical outcomes following coronary artery bypass grafting (CABG) remains controversial. Our objective was to investigate the real-world relationship between BMI and in-hospital clinical course and mortality, in patients who underwent CABG. Methods: A sampled cohort of patients who underwent CABG between October 2015 and December 2016 was identified in the National Inpatient Sample (NIS) database. Outcomes of interest included in-hospital mortality, peri-procedural complications and length of stay. Patients were divided into 6 BMI (kg/m²) subgroups; (1) under-weight ≤19, (2) normal-weight 20-25, (3) over-weight 26-30, (4) obese I 31-35, (5) obese II 36-39, and (6) extremely obese ≥40. Multivariable logistic regression model was used to identify predictors of in-hospital mortality. Linear regression model was used to identify predictors of length of stay (LOS). Results: An estimated total of 48,710 hospitalizations for CABG across the U.S. were analyzed. The crude data showed a U-shaped relationship between BMI and study population outcomes with higher mortality and longer LOS in patients with BMI ≤ 19 kg/m² and in patients with BMI ≥40 kg/m² compared to patients with BMI 20-39 kg/m². In the multivariable regression model, BMI subgroups of ≤19 kg/m² and ≥40 kg/m² were found to be independent predictors of mortality. Conclusions: A complex, U-shaped relationship between BMI and mortality was documented, confirming the "obesity paradox" in the real-world setting, in patients hospitalized for CABG.

Case Report: Off Label Utilization of Topiramate and Metformin in Patients With BMI ≥50 kg/m2 Prior to Bariatric Surgery

FDA approved anti-obesity medications may not be cost effective for patients struggling with pre-operative weight loss prior to bariatric surgery. Metformin, a biguanide, and Topiramate, a carbonic anhydrase inhibitor, both cost effective medications, have demonstrated weight loss when used for the treatment of type 2 diabetes or seizures, respectively. The aim of the three cases is to demonstrate the clinical utility of topiramate and metformin for preoperative weight loss in patients with a body mass index (BMI) ≥ 50 kg/m² prior to bariatric surgery who are unable to follow the bariatric nutritional prescription due to a dysregulated appetite system Each patient was prescribed metformin and/or topiramate in an off-label manner in conjunction with lifestyle modifications and achieved >8% total body weight loss during the preoperative period.

The Influence of Obesity on Treatment and Outcome of Severely Burned Patients

Obesity and the related medical, social, and economic impacts are relevant multifactorial and chronic conditions that also have a meaningful impact on outcomes following a severe injury, including burns. In addition to burn-specific difficulties, such as adequate hypermetabolic response, fluid resuscitation, and early wound coverage, obese patients also present with common comorbidities, such as arterial hypertension, diabetes mellitus, or nonalcoholic fatty liver disease. In addition, the pathophysiologic response to severe burns can be enhanced. Besides the increased morbidity and mortality compared to burn patients with normal weight, obese patients present a challenge in fluid resuscitation, perioperative management, and difficulties in wound healing. The present work is an in-depth review of the current understanding of the influence of obesity on the management and outcome of severe burns.

Peripheral Cardiopulmonary Bypass in Two Patients With Symptomatic Tracheal Masses: Perioperative Challenges

Tracheal tumors or masses causing critical airway obstruction require resection for symptom relief. However, the location and extent of these tumors or masses often preclude conventional general anesthesia and tracheal intubation. Peripheral cardiopulmonary bypass often is required before anesthetizing these patients. Herein, two cases of patients with tracheal masses, in whom awake peripheral cardiopulmonary bypass was instituted, are reported. The first case was that of an obese male child weighing 102 kg, with tracheal rhinoscleroma, who developed Harlequin, or north-south, syndrome after institution of femorofemoral venoarterial partial cardiopulmonary bypass. The second case was that of a female patient with adenoid cystic carcinoma of the trachea causing near-total central airway occlusion. She had severe pulmonary artery hypertension, which prevented the use of venovenous bypass. Instead, femoral vein-axillary artery venoarterial bypass was established to avoid Harlequin syndrome. Some of the challenges encountered were the development of Harlequin syndrome with risk of myocardial and cerebral ischemia, type and conduct of extracorporeal bypass, choice of monitoring sites, and provision of regional anesthesia for peripheral extracorporeal cannulations. Management of such patients needs frequent troubleshooting and multidisciplinary coordination for a successful surgical outcome.

COVID's Razor: RAS Imbalance, the Common Denominator Across Disparate, Unexpected Aspects of COVID-19

A modern iteration of Occam's Razor posits that "the simplest explanation is usually correct." Coronavirus Disease 2019 involves widespread organ damage and uneven mortality demographics, deemed unexpected from what was originally thought to be "a straightforward respiratory virus." The simplest explanation is that both the expected and unexpected aspects of COVID-19 share a common mechanism. Silent hypoxia, atypical acute respiratory distress syndrome (ARDS), stroke, olfactory loss, myocarditis, and increased mortality rates in the elderly, in men, in African-Americans, and in patients with obesity, diabetes, and cancer-all bear the fingerprints of the renin-angiotensin system (RAS) imbalance, suggesting that RAS is the common culprit. This article examines what RAS is and how it works, then from that baseline, the article presents the evidence suggesting RAS involvement in the disparate manifestations of COVID-19. Understanding the deeper workings of RAS helps one make sense of severe COVID-19. In addition, recognizing the role of RAS imbalance suggests potential routes to mitigate COVID-19 severity.

Massive Localized Abdominal Lymphedema Treatment Challenges

Massive localized lymphedema of the abdomen is a rare condition resulting from a neglected lower abdominal pannus associated with significant disability and morbidity. Compared to other surgical procedures, postbariatric surgery is usually considered a financial drain. In the United Kingdom, this requires National Health Service approval and delays may lead to sequelae that adversely impact on patients' quality of life with increased morbidity. We present a wheelchair-bound patient whose body mass index increased from 53 to 82, while awaiting funding approval increasing her anesthetic and surgical risks. A multidisciplinary approach is mandatory for preoperative, intraoperative, and postoperative care for these patients including anesthetic input and high dependency unit care. Managing this patient was a significant anesthetic and surgical challenge with 47-kg resected tissue. The planning and perioperative measures to minimize morbidity are discussed.

Learning disability and obesity: a case report of challenges and reasonable adjustments

Background When anxious, patients with learning disabilities may display challenging behaviour. The prevalence of obesity in patients with learning disabilities is rising and can increase the complexity of management. Reasonable adjustments are often necessary in order for treatment to be successful.Case report A 41-year-old male patient with a severe learning disability, autism and obesity was referred to the dental hospital for dental treatment. The patient frequently demonstrated physically challenging behaviour, particularly when in unfamiliar environments. In order for the patient to access care, a multidisciplinary team (MDT) approach with a number of reasonable adjustments was required. The patient was then able to receive treatment under general anaesthesia (GA) from not only the special care dentistry team, but also additional medical specialties.Discussion A holistic approach to care is important in this patient group in order to reduce health inequalities. Clinicians should be aware of their role in the screening and referral of patients with obesity.Conclusion Reasonable adjustments and a team approach are essential to the dental management of patients with learning disabilities. Management is becoming increasingly complex as obesity continues to be a growing problem among this group.

Metabolic control of gene transcription in non-alcoholic fatty liver disease: the role of the epigenome

Non-alcoholic fatty liver disease (NAFLD) is estimated to affect 24% of the global adult population. NAFLD is a major risk factor for the development of cirrhosis and hepatocellular carcinoma, as well as being strongly associated with type 2 diabetes and cardiovascular disease. It has been proposed that up to 88% of obese adults have NAFLD, and with global obesity rates increasing, this disease is set to become even more prevalent. Despite intense research in this field, the molecular processes underlying the pathology of NAFLD remain poorly understood. Hepatic intracellular lipid accumulation may lead to dysregulated tricarboxylic acid (TCA) cycle activity and associated alterations in metabolite levels. The TCA cycle metabolites alpha-ketoglutarate, succinate and fumarate are allosteric regulators of the alpha-ketoglutarate-dependent dioxygenase family of enzymes. The enzymes within this family have multiple targets, including DNA and chromatin, and thus may be capable of modulating gene transcription in response to intracellular lipid accumulation through alteration of the epigenome. In this review, we discuss what is currently understood in the field and suggest areas for future research which may lead to the development of novel preventative or therapeutic interventions for NAFLD.

Peri-anaesthetic mortality and nonfatal gastrointestinal complications in pet rabbits: a retrospective study on 210 cases

OBJECTIVE

The aim of this study was to determine the incidence and the associated risk factors of peri-anaesthetic mortality and gastrointestinal complications in pet rabbits.

STUDY DESIGN

Retrospective cohort study.

ANIMALS

A total of 185 pet rabbits admitted to the Exotic Referal Service of Beaumont Sainsbury's Animal Hospital over the period 2009-2016.

METHODS

The clinical records of the rabbits were obtained from the database. To evaluate the incidence of peri-anaesthetic mortality, three possible outcomes were considered: alive, dead or euthanized within the 72 hours following the anaesthetic event. Food intake and stool production during the first 72 hours following the anaesthetic event were evaluated to investigate the occurrence of gastrointestinal complications. Thereafter, various hypothesized risk factors, including administration of alpha-2 agonists, body weight, American Society of Anaesthesiologists classification and endotracheal intubation were tested against peri-anaesthetic mortality and gastrointestinal complications, with both univariate and multivariate binary logistic regression.

RESULTS

Twenty-five out of 185 rabbits underwent two anaesthetic events; therefore, data from 210 cases were used. Of these 210 cases, six died during sedation or general anaesthesia and four (one of which euthanized) died during the first 72 postoperative hours, accounting for an actual mortality rate equal to 4.8% (95% confidence interval, 0.025-0.086). Peri-anaesthetic gastrointestinal complications developed in 77 (38%) out of the 204 anaesthetic events whose outcome was not intraoperative death (95% confidence interval, 0.314-0.446). Species-specific risk factors could not be identified for peri-anaesthetic mortality; however, the odds for post-anaesthetic gastrointestinal complications increased significantly with body weight (p = 0.01).

CONCLUSIONS AND CLINICAL RELEVANCE

Our findings confirm that rabbits continue to have a higher incidence of peri-anaesthetic mortality than dogs and cats, and highlight a high risk for nonfatal peri-anaesthetic gastrointestinal complications in this species.

The effect of UGT1A9, CYP2B6 and CYP2C9 genes polymorphism on individual differences in propofol pharmacokinetics among Polish patients undergoing general anaesthesia

Propofol (2,6-diisopropylphenol) is one of the safest and most commonly used anaesthetic agents for intravenous general anaesthesia. However, in clinical practice, a large inter-individual variability in response to propofol is observed. To limit the risk of adverse effects, pharmacogenetic investigations are recommended. The aim of our study was to verify the impact of genetic changes c.516G>T in the CYP2B6, c.98T>C in the UGT1A9 and c.1075A>C in the CYP2C9 genes on the individual propofol pharmacokinetic profile in the Polish patients undergoing general anaesthesia. Eighty-five patients from the Department of Anaesthesiology and Intensive Therapy, Regional Hospital in Poznan, Poland, anaesthetised with propofol for surgery, were enrolled in the study. We have genotyped CYP2B6, UGT1A9 and CYP2C9 polymorphisms with the use of pyrosequencing. HPLC measurements of propofol plasma concentration were applied for a pharmacokinetic analysis of the anaesthetic. We identified poor (20), intermediate (42) and rapid (23) metabolisers of propofol, which constituted 24%, 49% and 27% of the group, respectively. Homozygotes c.516 T/T in the CYP2B6 gene were statistically more often found in the rapid metabolisers group (p < 0.05). However, polymorphisms c.98T>C in the UGT1A9 and c.1075A>C in the CYP2C9 genes did not affect the pharmacokinetic profile of propofol. The mean propofol retention time (MRT) correlated with the patient’s body mass index (BMI) (p < 0.05). From all the analysed changes, only polymorphism c.516G>T in the CYP2B6 gene and BMI affect the metabolism rate of propofol and may play an important role in the optimisation of propofol anaesthesia.

Airway management of the morbidly obese patient

A UK study found that obese patients are twice as likely as non-obese patients to develop airway problems during general anaesthesia (Cook et al 2011). This article focuses on airway management of morbidly obese patients during anaesthesia and examines the associated respiratory, gastric, and existing co-morbidity complications that can be expected. Strategies that practitioners can use to reduce these risks are discussed.

Evaluation of the site specificity of acute disuse muscle atrophy developed during a relatively short period in critically ill patients according to the activities of daily living level: A prospective observational study

INTRODUCTION

In critically ill patients, excessive bed rest and immobilisation have been shown to cause disuse muscle atrophy, which contributes to prolonged hospitalisation and decreased activity of daily living (ADL) levels. However, the degree and site specificity of acute disuse muscle atrophy in critically ill patients during a relatively short intensive care unit (ICU) stay have not been fully elucidated.

METHODS

Critically ill patients, who required bed rest on ICU admission, were eligible for this study. The degree of skeletal muscle atrophy was evaluated on the day of, and 72 and 144h after ICU admission by measuring the limb circumference in ADL-dependent or -independent patients separately at five different sites: the midpoint of the upper limb between the acromion and the olecranon, the maximum diameter of the triceps surae in the lower leg, and three different sites in the thigh at 5, 10, and 15cm above the superior pole of the patella. Value of the limb circumference was presented as a percentage relative to the baseline (median).

RESULTS

In ADL-dependent patients, limb circumferences at all five sites were decreased significantly at 144h compared with the baseline (98.9-100% in the upper limbs, 97.1-97.2% in the lower legs, and 96.5-99.1% in the thighs), but not at 72h. In contrast, the limb circumferences at almost all sites decreased significantly at both 72 and 144h (100% in the upper limbs, 94.5-94.7% in the lower legs, and 89.7-94.7% in the thighs), compared with the baseline in ADL-independent patients. Muscle atrophy was greater at the four different lower-limb sites compared to the upper limb during 144h in the ICU in the ADL-independent, but not in the ADL-dependent patients.

CONCLUSIONS

Compared to ADL-dependent patients, ADL-independent patients are prone to develop muscle weakness, especially in the lower limbs.

Laparoscopic appendectomy under spinal anesthesia with dexmedetomidine infusion

BACKGROUND

Laparoscopic appendectomy (LA) is rarely performed under regional anesthesia because of pneumoperitoneum-related problems. We expected that dexmedetomidine would compensate for the problems arising from spinal anesthesia alone. Thus, we performed a feasibility study of spinal anesthesia with intravenous dexmedetomidine infusion.

METHODS

Twenty-six patients undergoing LA received spinal anesthesia with intravenous dexmedetomidine infusion. During surgery, the patient's pain or discomfort was controlled by supplemental fentanyl or ketamine injection, and all adverse effects were evaluated.

RESULTS

No patient required conversion to general anesthesia, and all operations were completed laparoscopically without conversion to open surgery. Seventeen (65.4%) patients required supplemental injection of fentanyl or ketamine. Bradycardia occurred in seven (26.9%) patients.

CONCLUSIONS

Spinal anesthesia with dexmedetomidine infusion may be feasible for LA. However, additional analgesia, sedation, and careful attention to the potential development of bradycardia are needed for a successful anesthetic outcome.

The relationship between obesity and prescription of smoking cessation medications

The objective of this study was to examine the differences in prescription of smoking cessation medications among smokers with different body mass index (BMI) classifications. A retrospective cross-sectional study was conducted using National Ambulatory Medical Care Survey data (2006-2010). Self-reported current smokers aged 18 years and older were included in the study. The outcome of interest was receiving a prescription for a Food and Drug Administration-approved smoking cessation medication. Multivariate logistic regression was performed to assess the association between the outcome variable and the main independent variable (BMI classification), controlling for other covariates. The results showed that overweight, obese, and severely obese smokers were less likely to be prescribed a smoking cessation medication as compared to normal weight smokers. Although 5.11% of normal weight smokers were prescribed a smoking cessation medication, only 3.70% of overweight smokers, 3.41% of obese smokers, and 2.50% of severely obese smokers were prescribed a smoking cessation medication. In addition, older smokers, whites, smokers visiting primary care providers, smokers receiving tobacco counseling, and nondiabetic smokers were more likely to be prescribed a smoking cessation medication. Lower prescription of smoking cessation medications among overweight, obese, and severely obese smokers might be driven by patients' health concerns and behavioral factors or providers' treatment preferences or biases. The disparity in smoking cessation medication prescription among smokers with different BMI classifications raises quality of care and health care concerns for overweight, obese, and severely obese smokers.

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.

Evaluation of extended interval dosing aminoglycosides in the morbidly obese population

Aminoglycoside dosing has been studied in the obese population, typically recommending an adjusted weight utilizing a 40% dosing weight correction factor (IBW + 0.4 × (TBW-IBW)). These studies included limited numbers of morbidly obese patients and were not done in the era of extended interval aminoglycoside dosing. Here, we report a retrospective evaluation of morbidly obese patients receiving gentamicin or tobramycin at our hospital. The objective of this study was to evaluate the accuracy of the commonly recommended adjusted weight for weight-based dosing. There were 31 morbidly obese patients who received gentamicin or tobramycin 5-7 mg/kg every 24 hours using a 40% dosing weight correction factor. Our institution utilizes 16-hour postdose concentrations to monitor extended interval aminoglycosides. Twenty-two of the 31 patients (71%) achieved an appropriate serum drug concentration. Four patients (13%) were found to be supratherapeutic and 5 patients (16%) subtherapeutic. The only variable that correlated with supratherapeutic levels was older age (P = 0.0378). Our study helps to validate the current dosing weight correction factor (40%) in the morbidly obese population. We recommend caution when dosing aminoglycosides in morbidly obese patients who are of older age.

Anesthetic challenges in the obese patient

Obesity seems to be the modern concern to society. An increasing number of obese patients present annually to surgical wards to undergo surgical procedures. As morbid obesity affects most of the vital organs, the anesthesiologist must be prepared to deal with several challenges. These include the preoperative evaluation of the consequences of obesity, particularly on cardiac, respiratory, and metabolic systems; airway management; different pharmacokinetic and pharmacodynamic drug regimen; and perioperative management (i.e., hemodynamic, respiratory, and hyperglycemic). This paper reviews and assesses the most important anesthetic issues in managing obese patients.

Lung physiology and obesity: anesthetic implications for thoracic procedures

Obesity is a worldwide health problem affecting 34% of the American population. As a result, more patients requiring anesthesia for thoracic surgery will be overweight or obese. Changes in static and dynamic respiratory mechanics, upper airway anatomy, as well as multiple preoperative comorbidities and altered drug metabolism, characterize obese patients and affect the anesthetic plan at multiple levels. During the preoperative evaluation, patients should be assessed to identify who is at risk for difficult ventilation and intubation, and postoperative complications. The analgesia plan should be executed starting in the preoperative area, to increase the success of extubation at the end of the case and prevent reintubation. Intraoperative ventilatory settings should be customized to the changes in respiratory mechanics for the specific patient and procedure, to minimize the risk of lung damage. Several non invasive ventilatory modalities are available to increase the success rate of extubation at the end of the case and to prevent reintubation. The goal of this review is to evaluate the physiological and anatomical changes associated with obesity and how they affect the multiple components of the anesthetic management for thoracic procedures.

Obesity and Obstetric Anaesthesia

Obesity is increasing in the population as a whole, and especially in the obstetric population, among whom pregnancy-induced physiological changes impact on those already present due to obesity. In particular, changes in the cardiovascular and respiratory systems during pregnancy further alter the physiological effects and comorbidities of obesity. Obese pregnant women are at increased risk of diabetes, hypertensive disorders of pregnancy, ischaemic heart disease, congenital malformations, operative delivery, postpartum infection and thromboembolism. Regional analgesia and anaesthesia is usually preferred but may be challenging. Obese pregnant women appear to have increased morbidity and mortality associated with caesarean delivery and general anaesthesia for caesarean delivery in particular, and more anaesthesia-related complications. This article summarises the physiological and pharmacological implications of obesity and pregnancy and describes the issues surrounding the management of these women for labour and delivery.

A comparison between the Boussignac™ continuous positive airway pressure mask and the venturi mask in terms of improvement in the PaO2/F(I)O2 ratio in morbidly obese patients undergoing bariatric surgery: a randomized controlled trial

PURPOSE

This study compared the Boussignac™ continuous positive airway pressure (CPAP) mask with the venturi face mask in terms of the postoperative PaO2/F(I)O2 (PF) ratio in morbidly obese patients after bariatric surgery.

METHODS

Following hospital Research Ethics Board approval and written informed consent, morbidly obese (body mass index > 35 kg·m(-2)) patients undergoing bariatric surgery were recruited. The patients were anesthetized and laparoscopic Roux-en-Y gastric bypass was performed. Patients were assigned randomly to receive either the Boussignac (Boussignac Group) or the venturi face mask (Venturi Group) immediately after tracheal extubation. Patients were transported to the postanesthesia care unit, and the respective devices were applied for one hour. The PF ratio was recorded after tracheal intubation and at one hour and two hours post extubation. The percent forced expiratory volume (%FEV1) and the percent forced vital capacity (%FVC) were recorded preoperatively and at one hour and two hours post extubation. Independent Student's t tests were used for continuous variables, and the Chi square test was used for categorical variables. P < 0.05 was considered statistically significant.

RESULTS

Eighty-one patients (Group Boussignac, n = 43; Group Venturi, n = 38) completed the study. Mean ages and body mass indices were similar in the two groups. At one hour post extubation, the PF ratio in the Boussignac Group was 361 (170) compared with 279 (91) in the Venturi Group (P = 0.007), and at two hours post extubation, the PF ratio in the Boussignac Group was 371 (162) compared with 323 (127) in the Venturi Group (P = 0.1). The postoperative %FEV(1) and %FVC were comparable in both groups at all time points.

CONCLUSION

Compared with the venturi mask, the Boussignac CPAP mask improves the postoperative PF ratio in morbidly obese patients after bariatric surgery. The postoperative %FEV1 and %FVC are comparable for both groups.