Perioperative management of the severely obese patient: a selective pathophysiological review

Bariatric Surgery Effect on the Crosstalk of PAI-1 and PCSK9 to Regulate the Metabolic Changes in Patients with Obesity

BACKGROUND

Adiposity favors several metabolic disorders with an exacerbated chronic pro-inflammatory status and tissue damage, with high levels of plasminogen activator inhibitor type 1 (PAI-1) and proprotein convertase subtilisin/kexin type 9 (PCSK9).

OBJECTIVE

To demonstrate the influence of bariatric surgery on the crosstalk between PAI-1 and PCSK9 to regulate metabolic markers.

METHODS

Observational and longitudinal study of 190 patients with obesity and obesity-related comorbidities who underwent bariatric surgery. We measured, before and after bariatric surgery, the anthropometric variables and we performed biochemical analysis by standard methods (glucose, insulin, triglycerides [TG], total cholesterol, high-density lipoprotein cholesterol [HDL-C], low-density lipoprotein cholesterol [LDL-C] and TG/HDL-C ratio, PAI-1 and PCSK9 were measured by ELISA).

RESULTS

PAI-1 levels decreased significantly after bariatric surgery, and were positively correlated with lipids, glucose, and TG, with significance on PCSK9 and TG/HDL-C alleviating the insulin resistance (IR) and inducing a state reversal of type 2 diabetes (T2D) with a significant decrease in body weight and BMI (p <0.0001). Multivariate regression analysis predicted a functional model in which PAI-1 acts as a regulator of PCSK9 (p <0.002), TG (p <0.05), and BMI; at the same time, PCSK9 modulates LDL-C HDL-C and PAI-1.

CONCLUSIONS

After bariatric surgery, we found a positive association and crosstalk between PAI-1 and PCSK9, which modulates the delicate balance of cholesterol, favoring the decrease of circulating lipids, TG, and PAI-1, which influences the glucose levels with amelioration of IR and T2D, demonstrating the crosstalk between fibrinolysis and lipid metabolism, the two main factors involved in atherosclerosis and cardiovascular disease in human obesity.

The effect of obesity on the outcome of thoracic endovascular aortic repair: a systematic review and meta-analysis

Background

Obesity is a well-known predictor for poor postoperative outcomes of vascular surgery. However, the association between obesity and outcomes of thoracic endovascular aortic repair (TEVAR) is still unclear. This systematic review and meta-analysis was performed to assess the roles of obesity in the outcomes of TEVAR.

Methods

We systematically searched the Web of Science and PubMed databases to obtain articles regarding obesity and TEVAR that were published before July 2023. The odds ratio (OR) or hazard ratio (HR) was used to assess the effect of obesity on TEVAR outcomes. Body mass index (BMI) was also compared between patients experiencing adverse events after TEVAR and those not experiencing adverse events. The Newcastle-Ottawa Scale was used to evaluate the quality of the enrolled studies.

Results

A total of 7,849 patients from 10 studies were included. All enrolled studies were high-quality. Overall, the risk of overall mortality (OR = 1.49, 95% CI [1.02-2.17], p = 0.04) was increased in obese patients receiving TEVAR. However, the associations between obesity and overall complications (OR = 2.41, 95% CI [0.84-6.93], p = 0.10) and specific complications were all insignificant, including stroke (OR = 1.39, 95% CI [0.56-3.45], p = 0.48), spinal ischemia (OR = 0.97, 95% CI [0.64-1.47], p = 0.89), neurological complications (OR = 0.13, 95% CI [0.01-2.37], p = 0.17), endoleaks (OR = 1.02, 95% CI [0.46-2.29], p = 0.96), wound complications (OR = 0.91, 95% CI [0.28-2.96], p = 0.88), and renal failure (OR = 2.98, 95% CI [0.92-9.69], p = 0.07). In addition, the patients who suffered from postoperative overall complications (p < 0.001) and acute kidney injury (p = 0.006) were found to have a higher BMI. In conclusion, obesity is closely associated with higher risk of mortality after TEVAR. However, TEVAR may still be suitable for obese patients. Physicians should pay more attention to the perioperative management of obese patients.

The Overweight and Obese Patient in Oculofacial Plastic Surgery: A Narrative Review

PURPOSE

The oculofacial plastic surgeon will more frequently encounter challenges related to overweight and obese patients as the incidence rises. There is a paucity of data in the oculofacial plastic surgical literature regarding this topic. The goal of this review is to detail the role obesity plays in the perioperative course and the considerations for a surgeon treating this patient population.

METHODS

The authors conducted a computerized search using PubMed, Embase, and Google Scholar. The search terms used were "(obesity OR overweight) AND surgery," "(obesity OR overweight) AND oculoplastic," "(obesity OR overweight) AND oculofacial," "(obesity OR overweight) AND 'facial plastic surgery', " "(obesity OR overweight) AND 'bariatric surgery', " "(obesity OR overweight) AND (pre-operative OR post-operative OR intraoperative," " (obesity OR overweight) AND complications," "(obesity OR overweight) AND (facial plastic surgery) AND complications)," "(obesity OR overweight) AND eyelid," "(obesity OR overweight) AND (nasolacrimal OR 'nasolacrimal duct')," "(obesity OR overweight) AND IIH," "(obesity OR overweight) AND exophthalmos."

RESULTS

A total of 127 articles, published from 1952 to 2022 in the English language or with English translations were included. Articles published earlier than 2000 were cited for foundational knowledge. References cited in the identified articles were also used to gather further data for the review.

CONCLUSIONS

Overweight and obese patients pose specific challenges that the oculofacial plastic surgeon should be aware of to better optimize patient outcomes. Multiple comorbidities, poor wound healing, and nutritional deficits all contribute to the complications experienced in this patient population. Further investigation on overweight and obese patients is needed.

Patient selection in ambulatory surgery

Patient selection is important for ambulatory surgical practices. Proper patient selection for ambulatory practices will optimize resources and lead to increased patient and provider satisfaction. As the number and complexity of procedures in ambulatory surgical centers increase, it is important to ensure that patients are best cared for in facilities that can provide appropriate levels of care. This review addresses the multiple variables and resources that should be considered when selecting patients for anesthesia in ambulatory centers and offices.

Obesity is Not Associated with Adverse Perioperative or Poorer Clinical Outcomes following Thoracic and Fenestrated-Branched Endovascular Aortic Repair

BACKGROUND

Obesity is a risk factor for higher morbidity and mortality following open aortic repair but currently there is limited literature on its impact on clinical and procedural outcomes following thoracic endovascular aortic repair (TEVAR) and branched-fenestrated endovascular aortic repair (B-FEVAR).

METHODS

We conducted a retrospective case-control analysis of a prospectively collected nonrandomized database to evaluate the effects of obesity on procedural and clinical outcomes after B-FEVAR/TEVAR in treatment of pararenal/thoracoabdominal aortic aneurysm and dissection at the University hospital of Nantes (France) between January 2016 and December 2021. Patients were divided in 2 groups according to their body mass index (BMI) and the rate of technical success, complications (renal, pulmonary, cardiac, and neurological events), 30-day and long-term survival, freedom from target vessel instability and reintervention were compared.

RESULTS

195 patients were included (mean age 69.6 DS±11.2; n = 135, 69.2% men; mean BMI: 26.6 kg/m2 range 19-41) totalling n = 72 (36.8%) TEVAR, n = 107 (55.4%) FEVAR and n = 14 (7.3%) BEVAR. Patients were divided in 2 groups [obese: BMI≥30 kg/m2n = 52 (26.7%); and nonobese, BMI<30 kg/m2, n = 143 (73.3%) that statistically differed only in terms of coronary artery disease (obese 42.3% vs. 26.6% nonobese, P = 0.035) and diabetes (obese 25% vs. 12.6% nonobese, P = 0.03). No statistical differences were noted in primary technical (94.2% vs. 94.4%, P = 1.00) and clinical (92.3% vs. 95.1%, P = 0.49) success. Overall morbidity (30.8% vs. 21.1%, P = 0.16), visceral vessels instability (1.9% vs. 1.4% P = 1.00), reintervention rate within 30 days (9.6% vs. 5.6% P = 0.33), 90 days (7.7% vs. 9.8%, P = 0.78) and during follow-up (9.8% vs. 20%, P = 0.14) were comparable. No statistical difference were noted in 30-day mortality (3.8% vs. 4.9%, P = 1.00) and the 2-year follow-up survival (86.8% vs. 78.4%, P = 0.180) between the 2 groups.

CONCLUSIONS

In this series, obesity was not associated to worst clinical outcomes or higher mortality rate following TEVAR/B-FEVAR. However, considering our small patient sample, a conclusive analysis on obesity as risk factors for adverse events after endovascular treatment is not possible. A larger sample from the collaboration of multiple centers will be required to obtain definitive conclusions.

The influence of metabolic syndrome in heart valve intervention. A multi-centric study

BACKGROUND

The effect of metabolic syndrome (MetS), defined as insulin resistance along with two or more of: obesity, atherogenic dyslipidaemia and elevated blood pressure, on postoperative complications after isolated heart valve intervention remains controversial. We hypothesized that MetS may negatively influence the postoperative course in these patients.

METHODS

Patients from 10 cardiac units who underwent isolated valve intervention (mitral± $\pm $  tricuspid repair/replacement (mitral valve surgery [MVS]) or surgical aortic valve replacement (SAVR), or transcatheter aortic valve replacement (TAVR) were included. MetS was defined according to the World Health Organization criteria. Primary outcome was in-hospital mortality and overall postoperative length of stay (LOS). Relevant postoperative complications were also recorded.

RESULTS

From 2010 to 2019, 17,283 patients underwent valve intervention. The MVS, SVAR, and TAVR accounted for the 39.4%, 48.2%, and 12.3% respectively of the whole. MetS compared to no-MetS was associated to higher mortality in the MVS group (6.5% vs. 2%, p < .001), but not in the SAVR and TAVR group. In both surgical cohorts, MetS was associated with increased complications including red blood cells transfusion, renal failure, mechanical ventilation time, intensive care and overall postoperative LOS (11 (9) vs. 10 (6), p < .001 and 10 (6) versus 10 (5) days, p = .002, MVS and [SAVR]). No differences were found in the TAVR cohort, with similar mortality and complications.

CONCLUSION

MetS was associated to more postoperative complications, with higher mortality in the MVS group. In the TAVR cohort, postoperative complications and mortality rate did not differ between patients with and without MetS, however LOS was longer in the MetS group.

The effect of timing of intravenous paracetamol on perioperative pain and cytokine levels following laparoscopic bariatric surgery, a randomized controlled trial

OBJECTIVE

Bariatric surgeries involve manipulation of the viscera and are associated with significant postoperative pain. Paracetamol is a nonopioid analgesic with a rapid onset, and it is effective and safe. The study compared the effects of pre- and postincisional intravenous paracetamol administration for optimal postoperative pain management in patients undergoing bariatric surgeries.

METHODS

This is a prospective, double-blinded, placebo-controlled randomized clinical trial of adult patients, admitted electively for laparoscopic bariatric surgery. The patients were randomly divided into two groups. One group of patients was given paracetamol at the beginning of the operation, prior to the surgical incision, the other group of patients received the same treatment at the end of the operation.

RESULTS

Patients who were given preincisional intravenous paracetamol presented significantly lower visual analog scale (VAS) scores following the surgery compared with patients who were given intravenous paracetamol in the last 30 minutes of the operation (VAS, median [IQR] = 2 [2-3] vs. 5 [3-6]; p &lt; 0.001). They also required fewer postoperative opioids and tramadol (in milligrams, respectively, 1 [0-5] vs. 7.5 [5-10] and 300 [100-400] vs. 400 [200-500]) compared with later analgesia administration (p &lt; 0.001 and p = 0.03). The levels of inflammatory markers measured at fixed intervals from paracetamol administration were not statistically different between the study groups.

CONCLUSION

Early analgesia with intravenous paracetamol, given before the surgical incision, may result in lower VAS scores postoperatively compared with the same treatment administered toward the end of the operation.

A review on the anesthetic management of obese patients undergoing surgery

There has been an observed increase in theprevalence of obesity over the past few decades. The prevalence of anesthesiology related complications is also observed more frequently in obese patients as compared to patients that are not obese. Due to the increased complications that accompany obesity, obese patients are now more often requiring surgical interventions. Therefore, it is important that anesthesiologists be aware of this development and is equipped to manage these patients effectively and appropriately. As a result, this review highlights the effective management of obese patients undergoing surgery focusing on the preoperative, perioperative and postoperative care of these patients.

Buprenorphine differentially alters breathing among four congenic mouse lines as a function of dose, sex, and leptin status

The opioid buprenorphine alters breathing and the cytokine leptin stimulates breathing. Obesity increases the risk for respiratory disorders and can lead to leptin resistance. This study tested the hypothesis that buprenorphine causes dose-dependent changes in breathing that vary as a function of obesity, leptin status, and sex. Breathing measures were acquired from four congenic mouse lines: female and male wild type C57BL/6J (B6) mice, obese db/db and ob/ob mice with leptin dysfunction, and male B6 mice with diet-induced obesity. Mice were injected intraperitoneally with saline (control) and five doses of buprenorphine (0.1, 0.3, 1.0, 3.0, 10 mg/kg). Buprenorphine caused dose-dependent decreases in respiratory frequency while increasing tidal volume, minute ventilation, and respiratory duty cycle. The effects of buprenorphine varied significantly with leptin status and sex. Buprenorphine decreased minute ventilation variability in all mice. The present findings highlight leptin status as an important modulator of respiration and encourage future studies aiming to elucidate the mechanisms through which leptin status alters breathing.

Patients with sleep-disordered breathing for bariatric surgery

The prevalence of patients with obesity continues to rise worldwide and has reached epidemic proportions. There is a strong correlation between obesity and sleep-disordered breathing (SDB), and, in particular, obstructive sleep apnea (OSA). OSA is often undiagnosed in the surgical population. Bariatric surgery has been recognized as an effective treatment option for both obesity and OSA. Laparoscopic bariatric procedures, particularly laparoscopic sleeve gastrectomy (LSG), have become the most frequently performed procedures. OSA has been identified as an independent risk factor for perioperative complications and failure to recognize and prepare for patients with OSA is a major cause of postoperative adverse events, suggesting that all patients undergoing bariatric surgery should be screened preoperatively for OSA. These patients should be treated with an opioid-sparing analgesic plan and continuous positive airway pressure (CPAP) perioperatively to minimize respiratory complications. With the number of bariatric surgical patients with SDB likely to continue rising, it is critical to understand the best practices to manage this patient population.

The Impact of Metabolic Syndrome on Microvascular Head and Neck Reconstruction: An ACS-NSQIP data analysis

BACKGROUND

Metabolic syndrome (MetS) can predispose patients to poorer surgical outcomes. In this study, we sought to evaluate the impact of MetS on the postoperative outcomes of head and neck microvascular reconstruction.

METHODS

Review of the 2015-2019 NSQIP database identified 5,323 cases of microvascular reconstruction, of which 3,809 were head and neck cases. Of the included patients, 184 had MetS and 3625 did not. The groups were compared in terms of demographics and comorbidities. Postoperative outcomes assessed included mortality, average operative time and length of hospital stay, surgical and medical complications, and nonhome discharge.

RESULTS

The MetS group had higher rates of medical complications (p<0.0001), sepsis (p=0.02), septic shock (p=0.01), and skilled care-discharge (p=0.0004). Analysis by flap type revealed that MetS patients receiving free skin flaps experienced higher rates of organ space infection (p=0.02), sepsis (p<0.0001), and lower home-discharge (p=0.01). In the free muscle group, superficial incisional infection (p=0.04), UTI (p=0.02), and septic shock (p=0.01) were higher in MetS patients. Stratification by surgical site showed that the occurrence of sepsis was significantly higher in the patients receiving microvascular flap reconstruction of the larynx (p=0.04) or tongue(p=0.03). Stratification of the MetS patients according to treatment for diabetes showed that patients receiving insulin experienced a higher rate of superficial incisional infection (p=0.04). A multivariate analysis verified significantly higher rates of medical complications (p<0.0001), sepsis (p=0.03) and septic shock (p=0.01) in the MetS group.

CONCLUSION

Patients with MetS undergoing head and neck microvascular reconstruction are at increased risk of postoperative medical complications, including sepsis and septic shock, and are more likely to be discharged to a skilled care facility. Surgical outcomes were found to depend on the type of flap and site of surgery.

Intraoperative Blood Pressure Monitoring in Obese Patients

BACKGROUND

The optimal method for blood pressure monitoring in obese surgical patients remains unknown. Arterial catheters can cause potential complications, and noninvasive oscillometry provides only intermittent values. Finger cuff methods allow continuous noninvasive monitoring. The authors tested the hypothesis that the agreement between finger cuff and intraarterial measurements is better than the agreement between oscillometric and intraarterial measurements.

METHODS

This prospective study compared intraarterial (reference method), finger cuff, and oscillometric (upper arm, forearm, and lower leg) blood pressure measurements in 90 obese patients having bariatric surgery using Bland-Altman analysis, four-quadrant plot and concordance analysis (to assess the ability of monitoring methods to follow blood pressure changes), and error grid analysis (to describe the clinical relevance of measurement differences).

RESULTS

The difference (mean ± SD) between finger cuff and intraarterial measurements was -1 mmHg (± 11 mmHg) for mean arterial pressure, -7 mmHg (± 14 mmHg) for systolic blood pressure, and 0 mmHg (± 11 mmHg) for diastolic blood pressure. Concordance between changes in finger cuff and intraarterial measurements was 88% (mean arterial pressure), 85% (systolic blood pressure), and 81% (diastolic blood pressure). In error grid analysis comparing finger cuff and intraarterial measurements, the proportions of measurements in risk zones A to E were 77.1%, 21.6%, 0.9%, 0.4%, and 0.0% for mean arterial pressure, respectively, and 89.5%, 9.8%, 0.2%, 0.4%, and 0.2%, respectively, for systolic blood pressure. For mean arterial pressure and diastolic blood pressure, absolute agreement and trending agreement between finger cuff and intraarterial measurements were better than between oscillometric (at each of the three measurement sites) and intraarterial measurements. Forearm performed better than upper arm and lower leg monitoring with regard to absolute agreement and trending agreement with intraarterial monitoring.

CONCLUSIONS

The agreement between finger cuff and intraarterial measurements was better than the agreement between oscillometric and intraarterial measurements for mean arterial pressure and diastolic blood pressure in obese patients during surgery. Forearm oscillometry exhibits better measurement performance than upper arm or lower leg oscillometry.

EDITOR’S PERSPECTIVE

Effects of Obstructive Sleep Apnea and Obesity on Morphine Pharmacokinetics in Children

BACKGROUND

Obesity increases susceptibility to chronic pain, increases metabolism, and is associated with obstructive sleep apnea syndrome (OSAS), all which can complicate perioperative pain management of patients. In addition, obesity and OSAS can cause elevation of the adipose-derived hormone leptin, which increases metabolism. We hypothesized that obesity along with sleep apnea and leptin independently enhance morphine pharmacokinetics.

METHODS

Children 5-12 years of age who were presenting for surgery were administered a morphine dose of 0.05 mg/kg. Blood was collected at baseline and at subsequent preset times for pharmacokinetic analysis of morphine and its metabolites. Three groups were studied: a nonobese group with severe OSAS, an obese group with severe OSAS, and a control group.

RESULTS

Thirty-four patients consisting of controls (n = 16), nonobese/OSAS (n = 8), and obese/OSAS (n = 10) underwent analysis. The obese/OSAS group had a higher dose-adjusted mean maximum morphine concentration (CMAX) over 540 minutes compared to the controls (P < .001) and those with only OSAS (P = .014). The obese/OSAS group also had lower volume of distribution (Vd) when compared to OSAS-only patients (P = .007). In addition, those in the obese/OSAS group had a higher morphine 3-glucuronide (M3G) maximum concentration (P = .012) and a higher ratio of M3G to morphine than did the control group (P = .011). Time to maximum morphine 6-glucuronide (M6G) concentration was significantly lower in both nonobese/OSAS and obese/OSAS groups than in the control group (P < .005). C-reactive protein (CRP), interleukin (IL)-10, and leptin were all higher in the obese/OSAS group than in controls (P = .004, 0.026, and <0.001, respectively), and compared to OSAS-only patients, CRP (P = .013) and leptin (P = .002) levels were higher in the obese/OSAS group.

CONCLUSIONS

The combination of obesity and OSAS was associated with an increase in morphine metabolism compared with that in normal-weight controls. Our previous study in mice demonstrated that obesity from leptin deficiency decreased morphine metabolism, but that metabolism normalized after leptin replacement. Leptin may be a cause of the increased morphine metabolism observed in obese patients.

Comparison of glottic visualisation through supraglottic airway device (SAD) using bronchoscope in the ramped versus supine 'sniffing air' position: A pilot feasibility study

Background and Aims:

Airway management in obese patients is associated with increased risk of difficult airway and intubation. After failed intubation, supraglottic airway-guided flexible bronchoscopic intubation (SAGFBI) may be required. It is uncertain whether SAGFBI is best performed in the ramped versus conventional supine “sniffing air” position. We conducted a feasibility study to evaluate the logistics of positioning, compared glottic views, and evaluated SAGFBI success rates.

Methods:

We conducted a prospective, pilot study in patients with a body mass index (BMI) 30–40 kg/m² undergoing elective operations requiring tracheal intubation. All patients were placed in a ramped position. After induction, a supraglottic airway device (SAD) was inserted. A flexible bronchoscope was inserted into the SAD and a photograph of the glottic view taken. The patient was repositioned to the supine position. A second photograph was taken. SAGFBI was performed. Images were randomised and assessed by two independent anesthetists.

Results:

Of 17 patients recruited, 15 patients were repositioned successfully. There were no differences in glottic views observed in the two positions. SAGFBI was successful in 92.9% of patients (median time 91.5 s). Haemodynamic changes were noted in 42.7% of patients which resolved spontaneously.

Conclusion:

Our pilot study was completed within 5 months, achieved low dropout rate and protocol feasibility was established. SAGFBI was successfully and safely performed in obese patients, with a median time of 91.5 s. The time taken for SAGFBI was similar to awake intubation using FBI and videolaryngoscopy. Our study provided preliminary data supporting future, larger-scale studies to evaluate glottic views in the ramped versus supine positions.

The Dentoalveolar Surgical Patient: Perioperative Principles Based on Contemporary Controversies

Dentoalveolar surgery comprises more than 50% of the practice of oral and maxillofacial surgeons worldwide and is the most commonly performed category of surgical procedure. Optimal strategies for management of many medical problems, however, remain unclear. Remaining current on medical and surgical perioperative strategies is a standard for best practice. This article provides contemporary approaches for the perioperative management of patients presenting for dentoalveolar surgery. Attention will be directed to the perioperative management of cardiovascular disease, diabetes, and obesity. These diseases are chosen owing to controversies with respect to good scientific evidence that supports a standard of perioperative care.

Awake Intubation via an Ambu AuraGain in a Patient With Extreme Obesity: A Case Report

Severe obesity is associated with increased morbidity and mortality. Airway management is challenging due to difficulties in positioning and airway management and altered pulmonary physiology. We report a case of awake flexible bronchoscopic intubation via an Ambu AuraGain in a patient with a body mass index of 54 kg/m scheduled for elective thyroidectomy. The procedure was well tolerated and easily performed in the full sitting position for optimal airway and ventilation and cardiovascular stability during intubation. To our knowledge, this is the first published report of awake flexible bronchoscopic intubation via an AuraGain, and we discuss our rationale for using this technique.

The clinical, functional and disability characteristics of patients with severe obesity presenting for non-bariatric surgery

The clinical and functional characteristics of patients with severe obesity who present for non-bariatric surgery have rarely been described. For this study, 293 such patients (mean body mass index 42 kg/m2) were investigated using their medical records, a 6-minute walk test, N-terminal pro B-type natriuretic peptide measurement, and the World Health Organization Disability Assessment Schedule 2.0 measure of disability. Cardiorespiratory disease and diabetes were common, with blood tests revealing a high probability of additional unexpected and undiagnosed renal and cardiac disease in a significant proportion of patients. One-third of patients had natriuretic peptide values that identify early left ventricular dysfunction in the community, with 16% above a value described as useful in predicting adverse outcomes for elective surgical patients. Only 10% of patients walked a distance within 10% of that predicted in six minutes, and 22% did not complete the test. Over one-third of patients (34%) had a clinically significant level of disability, with those unable to walk for six minutes describing higher levels of disability. Functional capacity as measured by the 6-minute walk test was significantly lower than would be expected from age, gender, and weight alone, and was related to age and degree of disability but not body mass index. We describe a severely obese population presenting for non-bariatric surgery who had significant levels of comorbid disease, functional impairment, and disability that were not apparent on routine preoperative assessment.

Patients' Perceptions of Short-Term Recovery After a Gastric Bypass

PURPOSE

To explore gastric bypass patients' perceptions of their postoperative recovery over 1 month.

DESIGN

A standardized questionnaire, the postoperative recovery profile, was used.

METHODS

Postoperative recovery profile is a multi-item questionnaire for self-assessment of general postoperative recovery. Participants were patients who had undergone gastric bypass surgery (n = 39). The changes in recovery between 1 day and 1 month postsurgery were evaluated by a statistical method developed specifically for analyzing changes in paired ordered data over time.

FINDINGS

Most of the symptoms and/or functions were significantly improved on a group level. The most marked improvement was to pain and sleeping difficulties followed by mobilization. In terms of the psychological items, the proportion of patients who indicated no problems was high at both endpoints. The items that deviated from the improvement pattern were appetite changes and gastrointestinal function which demonstrated a relatively high proportion of deterioration, and the individual variability was prominent.

CONCLUSIONS

There is a need for interventions to improve recovery on a group as well as an individual level.

A perioperative care map improves outcomes in patients with morbid obesity undergoing major surgery

BACKGROUND

The surgical management of patients with morbid obesity (body mass index ≥ 40) is notable for a relatively high risk of complications. To address this problem, a perioperative care map was developed using precautions and best practices commonly employed in bariatric surgery. It requires additional medical assessments, sleep apnea surveillance, more stringent guidelines for anesthetic management, and readily available bariatric operating room equipment, among other items. This care map was implemented in 2013 at 4 major urban teaching hospitals for use in patients undergoing all types of nonambulatory surgery with a body mass index greater than 40 kg/m². The impact on patient outcomes was evaluated.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program database was used to compare 30-day outcomes of morbidly obese patients before the year 2013 and after the years 2015 care-map implementation. In addition, trends in 30-day outcomes for morbidly obese patients were compared with those for non-obese patients.

RESULTS

Morbidly obese patients, between 2013 and 2015, saw an adjusted decrease in the rate of unplanned return to the operating room (OR = 0.49; P = .039), unplanned readmission (OR = 0.57; P = .006), total duration of stay (-0.87 days; P = .009), and postoperative duration of stay (-0.69 days; P = .007). Of these, total duration of stay (-0.86 days; P = .015), and postoperative duration of stay (-0.69 days; P = .012) improved significantly more for morbidly obese patients than for nonmorbidly obese patients.

CONCLUSION

Outcomes in morbidly obese patients improved from 2013 to 2015. Implementation of a perioperative care map may have contributed to these improvements. The care map should be further investigated and considered for more widespread use.

Leptin status alters buprenorphine-induced antinociception in obese mice with dysfunctional leptin receptors

Buprenorphine is an opiate used for pain management and to treat opiate addiction. The cytokine leptin can modulate nociception, but the extent to which buprenorphine-induced antinociception varies as a function of leptin signaling has not been characterized. Four congenic mouse lines with phenotypes that include differences in body weight and leptin status were used to test the hypothesis that the antinociceptive effects of buprenorphine vary as function of sex and leptin signaling. Each mouse line was comprised of males (n=12) and females (n=12) for a total of 96 animals. Groups included C57BL/6J (B6) mice (wild type), B6 mice with diet-induced obesity (DIO), obese B6.Cg-Lepob/J (ob/ob) mice lacking leptin, and obese B6.BKS(D)-Leprdb/J (db/db) mice with dysfunctional leptin receptors. The dependent measure was tail flick latency (TFL) in seconds for mouse-initiated tail removal from a warm water bath. Independent variables were intraperitoneal administration of saline (control) or buprenorphine (0.3mg/kg). Within every mouse line, buprenorphine significantly increased TFL relative to saline. Compared to the other mouse lines, db/db mice with dysfunctional leptin receptors had a significantly longer TFL after saline and after buprenorphine. TFL did not vary significantly by body weight or sex. The results provide novel support for the interpretation that acute thermal nociception is associated with altered leptin signaling.

Value of endometrial thickness assessed by transvaginal ultrasound for the prediction of endometrial cancer in patients with postmenopausal bleeding

PURPOSE

Histological confirmation of endometrial cancer by dilatation/curettage (D/C) in women with postmenopausal bleeding (PMB) can be challenging due to anesthesiological and/or surgical risks. Thus, less invasive methods for diagnostics are required to identify patients with minimal risk for endometrial cancer (EC) to avoid unnecessary surgical intervention. The objective of this single-center cohort study was to assess the diagnostic validity of transvaginal ultrasound (TVUS) measurements of endometrial thickness (ET) in patients with PMB for the detection of EC.

METHODS

A retrospective analysis of data from patients presenting between January 2005 and August 2014 at the Department of Obstetrics and Gynecology, University Hospital Ulm, Germany, with PMB and subsequent D/C was performed. Complete data with TVUS documentation of ET and histological results of tissue samples were available from 254 patients. In addition, data on age, body mass index (BMI), ASA-score, diabetes, hypertension, and hematological laboratory values (for a smaller subsample) were recorded. To identify independent risk factors, a multivariate logistic regression with endometrial cancer as binary response variable (yes/no) was performed. Diagnostic efficacy data for different ET cutoff points (≤1 to ≤26 mm) were obtained by a receiver operator characteristic (ROC) curve analysis.

RESULTS

The multivariate logistic regression revealed a significant independent predictive value for age and ET. However, none of the analyzed ET cutoff points showed optimal diagnostic validity, as all cutoff points with sensitivity rates above 90% (≤1 to ≤5 mm) had false positive rates of 70% and higher.

CONCLUSIONS

There is no ET cutoff point that provides good diagnostic accuracy and/or reliably excludes the presence of endometrial cancer in patients with PMB. Thus, our data analysis supports the actual German approach of histological evaluation of any PMB to confirm or exclude EC.

Controlled invasive mechanical ventilation strategies in obese patients undergoing surgery

INTRODUCTION

The obesity prevalence is increasing in surgical population. As the number of obese surgical patients increases, so does the demand for mechanical ventilation. Nevertheless, ventilatory strategies in this population are challenging, since obesity results in pathophysiological changes in respiratory function. Areas covered: We reviewed the impact of obesity on respiratory system and the effects of controlled invasive mechanical ventilation strategies in obese patients undergoing surgery. To date, there is no consensus regarding the optimal invasive mechanical ventilation strategy for obese surgical patients, and no evidence that possible intraoperative beneficial effects on oxygenation and mechanics translate into better postoperative pulmonary function or improved outcomes. Expert commentary: Before determining the ideal intraoperative ventilation strategy, it is important to analyze the pathophysiology and comorbidities of each obese patient. Protective ventilation with low tidal volume, driving pressure, energy, and mechanical power should be employed during surgery; however, further studies are required to clarify the most effective ventilation strategies, such as the optimal positive end-expiratory pressure and whether recruitment maneuvers minimize lung injury. In this context, an ongoing trial of intraoperative ventilation in obese patients (PROBESE) should help determine the mechanical ventilation strategy that best improves clinical outcome in patients with body mass index≥35kg/m².

Perioperative care map improves compliance with best practices for the morbidly obese

BACKGROUND

Morbid obesity can complicate perioperative management. Best practice guidelines have been published but are typically followed only in bariatric patients. Little is known regarding physician awareness of and compliance with these clinical recommendations for nonbariatric operations. Our study evaluated if an educational intervention could improve physician recognition of and compliance with established best practices for all morbidly obese operatively treated patients.

METHODS

A care map outlining best practices for morbidly obese patients was distributed to all surgeons and anesthesiologists at 4 teaching hospitals in 2013. Pre- and postintervention surveys were sent to participants in 2012 and in 2015 to evaluate changes in clinical practice. A chart audit performed postintervention determined physician compliance with distributed guidelines.

RESULTS

In the study, 567 physicians completed the survey in 2012 and 375 physicians completed the survey in 2015. Postintervention, statistically significant improvements were seen in the percentage of surgeons and anesthesiologists combined who reported changing their management of morbidly obese, operatively treated patients to comply with best practices preoperatively (89% vs 59%), intraoperatively (71% vs 54%), postoperatively (80% vs 57%), and overall (88% vs 72%). Results were similar when surgeons and anesthesiologists were analyzed separately. A chart audit of 170 cases from the 4 hospitals found that 167 (98%) cases were compliant with best practices.

CONCLUSION

After care map distribution, the percentage of physicians who reported changing their management to match best practices significantly improved. These findings highlight the beneficial impact this educational intervention can have on physician behavior. Continued investigation is needed to evaluate the influence of this intervention on clinical outcomes.

Peri-operative nutrition

Patients are frequently malnourished or are at risk of malnutrition before surgery. Peri-operative nutritional support can improve their outcomes. This review focuses on new developments in peri-operative nutrition, including: patient preparation and pre-operative fasting; the role of nutritional supplementation; the optimal route and timing of nutrient delivery; and the nutritional management of specific groups including critically ill, obese and elderly patients.

Perioperative sleep apnea: a real problem or did we invent a new disease?

Depending on the subpopulation, obstructive sleep apnea (OSA) can affect more than 75% of surgical patients. An increasing body of evidence supports the association between OSA  and perioperative complications, but some data indicate important perioperative outcomes do not differ between patients with and without OSA. In this review we will provide an overview of the pathophysiology of sleep apnea and the risk factors for perioperative complications related to sleep apnea. We also discuss a clinical algorithm for the identification and management of OSA patients facing surgery.

A comparative study of open, laparoscopic and robotic partial nephrectomy in obese patients

Objectives:

Partial nephrectomy is a standard intervention for the treatment of small renal tumors. Our study compares the outcomes of three different partial nephrectomy methods (open, laparoscopic and robotic assisted) in obese (≥30 Kg/m²) patients with renal tumors.

Materials and Methods:

Between 2005-2011, 66 obese patients had partial nephrectomy. Patients were divided into three groups according to intervention received: Open (n = 21), laparoscopic (n = 31) and robotic (n = 14). The outcome variables of blood loss, length of hospital stay, and complications were assessed.

Results:

Mean blood loss in the laparoscopic group (100 mls) was significantly less than open group (300 mls) and no difference between laparoscopic and robotic groups (150 mls). We observed a shorter median hospital stay in the laparoscopic group (two days) than open group (four days) and no difference between laparoscopic and robotic groups (three days). Three patients in the laparoscopic group had complications: Two grade II and one with grade III (based on Clavien-Dindo classification). Tumor location, pathology, grade, stage, patient gender, age, preoperative creatinine and postoperative creatinine were not different among the groups (P > 0.05). The mean tumor size in the laparoscopic group (2.70 cms) was significantly smaller than that of the open group (4.22 cm) (P < 0.05), but not statistically different from that of the robotic group (2.99 cm).

Conclusions:

Our study demonstrates that in obese patients, both laparoscopic and robotic partial nephrectomy are associated with less blood loss than open partial nephrectomy. Second, the length of the hospital stay was not related to the type of utilized intervention.

General anesthesia for the heaviest man in the world

The prevalence of obesity has increased greatly over the last 20 years, resulting in an increase in the number of bariatric and nonbariatric surgeries in this population. We present the case of a 20-year-old male, weighing 610 kg (1345 lb), and believed to be the heaviest living man in the world. After 4 months of rigorous in-hospital weight reduction, now weighing 510 kg (1125 lb), he underwent a laparoscopic gastric sleeve procedure under general anesthesia. This report describes the management of his anesthetic and exemplifies the challenges associated with this patient population.

From the Journal archives: Airway closure and lung volumes in surgical positions

AUTHORS

Douglas B. Craig, W.M. Wahba, Hillary Don

CITATION

Can Anaesth Soc J 1971; 18: 92-9.

PURPOSE

Surgery and anesthesia expose patients to moderate and sometimes extreme positioning changes that are often unphysiological. The purpose of this article is to highlight and contextualize a seminal study from the Journal archives that explores the effect of several commonly utilized surgical positions (supine, Trendelenburg and lithotomy) and age on basic lung volumes as well as the volume at which small airway closure (AC) (also known as closing volume [CV]) occurs. These factors were examined with the aim of determining which patient position variables could be of clinical significance to gas exchange in the perioperative period.

PRINCIPAL FINDINGS

This work showed that supine positioning, when compared with the seated position, results in a decrease of all lung volumes and capacities, including functional residual capacity (FRC) and CV. Trendelenburg positioning further decreases FRC, with no further changes induced by lithotomy positioning. Age is a clinically important factor in AC, occurring within the tidal volume range at a lower age when supine as compared with the seated position.

CONCLUSIONS

The work of Drs. D. Craig et al. published in the Journal more than 40 years ago was seminal to our understanding of how patient positioning has an important influence on lung volumes and on the age-related relationship between FRC and CV.

Tracheal intubation with a flexible intubation scope versus other intubation techniques for obese patients requiring general anaesthesia

BACKGROUND

The prevalence of obesity (body mass index (BMI) > 30 kg/m(2)) is increasing in both developed and developing countries, leading to a rise in the numbers of obese patients requiring general anaesthesia. Obese patients are at increased risk of anaesthetic complications, and tracheal intubation can be more difficult. Flexible intubation scopes (FISs) are recommended as an alternative method of intubation in these patients. Intubation with an FIS is considered an advanced method, requiring training and experience; therefore it may be underused in clinical practice. Patient outcomes following intubation with these scopes compared with other devices have not been systematically reviewed.

OBJECTIVES

We wished to compare the safety and effectiveness of a flexible intubation scope (FIS) used for tracheal intubation in obese patients (BMI > 30 kg/m(2)) with other methods of intubation, including conventional direct laryngoscopy, non-standard laryngoscopy and the use of intubating supraglottic airway devices. We aimed to compare the frequency of complications, as well as process indicators, such as time taken for intubation and the proportion of first attempts that were successful, between groups using the different methods of intubation.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and two trial registers on 18 January 2013, and performed reference checking and citation searching and contacted study authors to identify additional studies.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) of participants aged 16 years and older with a BMI > 30 kg/m(2) that had compared the use of an FIS for tracheal intubation with any one of three comparison groups: direct laryngoscopy; non-standard laryngoscopy (including indirect laryngoscopy using a videolaryngoscope (VLS) or a rigid or semi-rigid stylet); or intubation of supraglottic airway devices (SADs).

DATA COLLECTION AND ANALYSIS

We used standard methodological approaches expected by The Cochrane Collaboration, including independent review of titles, data extraction and risk of bias assessment by two investigators.

MAIN RESULTS

Three eligible studies were identified, all comparing the use of an FIS with a VLS. All studies were small, with only 131 participants in total across all trials. It was impossible for the intubators to be unaware of the device used, so all studies were at high risk of performance and detection bias for outcomes related to intubation. Because of substantial differences in design between the studies, we did not combine their results in meta-analyses. The results for all outcomes were inconclusive, with no differences noted between FIS and VLS. Two studies with experienced intubators reported first attempt success rates greater than 70% in both groups and less than 5% of participants requiring a change of intubation device. No evidence was found of any difference in difficulty or time taken between FIS and VLS intubation. No serious complications or airway trauma was reported, so we were unable to address these outcomes. Bleeding was uncommon, occurring in less than 5% of participants, and we found no evidence that it was more likely in the FIS group. One small study with a novice intubator reported no successful intubations using an FIS and compared with the use of an intubating SAD and stylet, as well as with a VLS. With only five participants in each group, no conclusions can be drawn from these additional comparisons.

AUTHORS' CONCLUSIONS

The evidence base is sparse, and the existing literature does not address the clinical questions of patient safety posed by this review. We are therefore unable to draw any conclusions on safety or effectiveness. More primary research is needed to investigate optimal intubation techniques in obese patients, and new studies should be powered to detect differences in complications and in success rates rather than process measures such as speed, which are of limited clinical importance.

The difficult airway with recommendations for management--part 2--the anticipated difficult airway

BACKGROUND

Appropriate planning is crucial to avoid morbidity and mortality when difficulty is anticipated with airway management. Many guidelines developed by national societies have focused on management of difficulty encountered in the unconscious patient; however, little guidance appears in the literature on how best to approach the patient with an anticipated difficult airway.

METHODS

To review this and other subjects, the Canadian Airway Focus Group (CAFG) was re-formed. With representation from anesthesiology, emergency medicine, and critical care, CAFG members were assigned topics for review. As literature reviews were completed, results were presented and discussed during teleconferences and two face-to-face meetings. When appropriate, evidence- or consensus-based recommendations were made, and levels of evidence were assigned.

PRINCIPAL FINDINGS

Previously published predictors of difficult direct laryngoscopy are widely known. More recent studies report predictors of difficult face mask ventilation, video laryngoscopy, use of a supraglottic device, and cricothyrotomy. All are important facets of a complete airway evaluation and must be considered when difficulty is anticipated with airway management. Many studies now document the increasing patient morbidity that occurs with multiple attempts at tracheal intubation. Therefore, when difficulty is anticipated, tracheal intubation after induction of general anesthesia should be considered only when success with the chosen device(s) can be predicted in a maximum of three attempts. Concomitant predicted difficulty using oxygenation by face mask or supraglottic device ventilation as a fallback makes an awake approach advisable. Contextual issues, such as patient cooperation, availability of additional skilled help, and the clinician's experience, must also be considered in deciding the appropriate strategy.

CONCLUSIONS

With an appropriate airway evaluation and consideration of relevant contextual issues, a rational decision can be made on whether an awake approach to tracheal intubation will maximize patient safety or if airway management can safely proceed after induction of general anesthesia. With predicted difficulty, close attention should be paid to details of implementing the chosen approach. This should include having a plan in case of the failure of tracheal intubation or patient oxygenation.

Patients requiring perioperative nutritional support

One of the most important factors affecting outcome and recovery from surgical trauma is preoperative nutritional status. Research in perioperative nutritional support has suffered from a lack of consensus as to the definition of malnutrition, no recognition of which nutrients are important to surgical healing, and a paucity of well-designed studies. In the past decade, there has been some activity to address this situation, recognizing the importance of nutrition as a therapy before surgery, after surgery, and possibly even during surgery.

Orthopedic trauma surgery in the morbidly obese patient

PURPOSE

The treatment of morbidly obese patients in orthopedic trauma differs in many ways compared to injured patients with normal body mass indices. This paper highlights key differences and ways to overcome obstacles.

METHODS

We present specific tips, as well as considerations for initial planning, positioning for surgery, intra-operative strategies, and a discussion on both anesthesia and imaging.

RESULTS

Several treatment strategies have been shown to have better results in morbidly obese patients. Pre-operative planning is necessary for minimizing risk to the patient.

CONCLUSION

The prevalence of morbid obesity has increased in the USA in the past quarter century. Treatment for orthopedic injuries in morbidly obese patients requires a multidisciplinary approach that addresses not only their orthopedic injuries, but also medical co-morbidities. A team of medicine doctors, anesthesiologists, X-ray technicians, physical and occupational therapists, respiratory therapists, and social workers is needed in addition to the orthopedic surgeon. Modifications in both pre-operative planning and intra-operative strategies may be necessary in order to accommodate the patient. This paper presents numerous technical tips that can aid in providing stable fixation for fractures, as well as addressing peri-operative issues specific to the morbidly obese.