Perioperative Care of the Obese Cardiac Surgical Patient

The Effect of Obesity on Short- and Long-Term Outcome after Surgical Treatment for Acute Type A Aortic Dissection

BACKGROUND

A paradox of lower morbidity and mortality in overweight or obese patients undergoing cardiac surgery has been described; however, knowledge about the influence of obesity in patients with acute Type A aortic dissection (AAD) is limited. This study aimed to evaluate the effect of obesity on short- and long-term outcomes after surgical treatment for AAD.

METHODS

Between 01/2004 and 12/2022, 912 patients with a BMI of 18.5 or greater were operated on for AAD. Patients were grouped according to their BMI (normal weight: BMI 18.5-24.9, n = 332; overweight: BMI 25-29.9, n = 367; obesity class I: BMI 30-34.9, n = 133; obesity class II+: BMI ≥ 35, n = 67), and the obtained clinical and surgical data were compared.

RESULTS

Obese patients were younger at the time of AAD (p = 0.001) and demonstrated higher rates of typical cardiovascular comorbidities (arterial hypertension, p = 0.005; diabetes mellitus, p < 0.001). The most important preoperative parameters, as well as the surgical approach, were similar between all four groups. The occurrence of renal failure requiring dialysis was higher in patients with BMI ≥ 35 (p = 0.010), but the in-hospital (p = 0.461) and long-term survival (p = 0.894) showed no significant differences.

CONCLUSIONS

There are no indications that the obesity paradox is applicable in the setting of AAD. Since obese patients are affected by AAD at a younger age, obesity might constitute a risk factor for AAD. However, obesity does not influence short- or long-term survival. Regardless of body weight, immediate surgical therapy remains the treatment of choice for AAD.

Rapid Aggravation of Rhabdomyolysis Caused by Daptomycin After Aortic Arch Replacement: A Case Report

Although rare, rhabdomyolysis is a serious complication of cardiothoracic surgery. Daptomycin is a polypeptide antimicrobial agent used to treat methicillin-resistant Staphylococcus aureus (MRSA) infections of the soft tissues. Daptomycin is associated with elevations in serum creatine kinase (CK). A 50-year-old man with acute Stanford A-type aortic dissection was performed Bentall procedure and total arch replacement with frozen elephant trunk. The CK level was 6,573 U/L on the first postoperative day (POD), suggesting rhabdomyolysis associated with lower limb ischemia. The CK level increased to 11,934 U/L on POD 2 and started to decrease thereafter. On POD 5, the patient had a suspected surgical site infection. Antibiotics were changed to empiric therapy of daptomycin and meropenem to address soft tissue MRSA infection. The CK level at the start of daptomycin administration was 4,122 U/L. However, the CK level rose to 21,813 U/L on POD 6. None of the findings suggested new-onset lower limb ischemia. Assuming that the rhabdomyolysis was induced by daptomycin, it was discontinued. The CK level peaked at 26,123 U/L on POD 8, after which it started to decrease and normalized on POD 16. Daptomycin should be used with extreme caution in patients recovering from rhabdomyolysis.

Variables associated with in-hospital and postdischarge outcomes after postcardiotomy extracorporeal membrane oxygenation: Netherlands Heart Registration Cohort

OBJECTIVES

Extracorporeal membrane oxygenation (ECMO) for postcardiotomy cardiogenic shock has been increasingly used without concomitant mortality reduction. This study aims to investigate determinants of in-hospital and postdischarge mortality in patients requiring postcardiotomy ECMO in the Netherlands.

METHODS

The Netherlands Heart Registration collects nationwide prospective data from cardiac surgery units. Adults receiving intraoperative or postoperative ECMO included in the register from January 2013 to December 2019 were studied. Survival status was established through the national Personal Records Database. Multivariable logistic regression analyses were used to investigate determinants of in-hospital (3 models) and 12-month postdischarge mortality (4 models). Each model was developed to target specific time points during a patient's clinical course.

RESULTS

Overall, 406 patients (67.2% men, median age, 66.0 years [interquartile range, 55.0-72.0 years]) were included. In-hospital mortality was 51.7%, with death occurring in a median of 5 days (interquartile range, 2-14 days) after surgery. Hospital survivors (n = 196) experienced considerable rates of pulmonary infections, respiratory failure, arrhythmias, and deep sternal wound infections during a hospitalization of median 29 days (interquartile range, 17-51 days). Older age (odds ratio [OR], 1.02; 95% CI, 1.0-1.04) and preoperative higher body mass index (OR, 1.08; 95% CI, 1.02-1.14) were associated with in-hospital death. Within 12 months after discharge, 35.1% of hospital survivors (n = 63) died. Postoperative renal failure (OR, 2.3; 95% CI, 1.6-4.9), respiratory failure (OR, 3.6; 95% CI, 1.3-9.9), and re-thoracotomy (OR, 2.9; 95% CI, 1.3-6.5) were associated with 12-month postdischarge mortality.

CONCLUSIONS

In-hospital and postdischarge mortality after postcardiotomy ECMO in adults remains high in the Netherlands. ECMO support in patients with higher age and body mass index, which drive associations with higher in-hospital mortality, should be carefully considered. Further observations suggest that prevention of re-thoracotomies, renal failure, and respiratory failure are targets that may improve postdischarge outcomes.

Case Report: Rhabdomyolysis in aneurysmal subarachnoid hemorrhage: A rare case with implications for management

Background

In recent years, some cases of rhabdomyolysis after surgery have been reported. In this report, we present an adult patient with rhabdomyolysis after intracranial aneurysm surgery.

Case Report

A 59-year-old male suffered from a coma, fever, and soy sauce urine after intracranial aneurysm clipping. A routine blood examination showed that liver and kidney function were impaired, and creatine phosphokinase(CK) and creatine phosphokinase isoenzyme(CK-MB) levels increased. Therefore, we consider patients with rhabdomyolysis after intracranial aneurysm surgery. A series of treatment schemes, such as intravenous fluid infusion, alkalized urine, and hemodialysis, were adopted immediately, and finally the patient was discharged safely.

Conclusion

For some postoperative patients, once the level of CK/CK-MB increases, acute renal damage occurs, and the urine color turns soy sauce, we should be alert to postoperative rhabdomyolysis.For those patients who have been diagnosed with rhabdomyolysis, we need to take timely treatment measures to avoid an unfortunate occurrence.

A study comparing outcomes between obese and nonobese patients with lumbar disc herniation undergoing surgery: a study of the Swedish National Quality Registry of 9979 patients

Background

This study aimed to evaluate whether an increasing grade of obesity is associated with inferior outcomes after lumbar disc herniation (LDH) surgery.

Methods

We retrieved data from the Swedish register for spine surgery regarding patients aged 20–64 who underwent LDH surgery from 2006–2016 and had preoperative and one-year postoperative data. A total of 4156 patients were normal weight, 4063 were overweight, 1384 had class I obesity, 317 had class II obesity and 59 had class III obesity (“morbid obesity”). Data included patient satisfaction, improvement in leg pain (assessed using the National Rating Scale; NRS; rating 0–10), disability (assessed using the Oswestry Disability Index; ODI; rating 0–100) and complications.

Results

At one year postsurgery, 80% of normal-weight patients, 77% of overweight patients and 74% of obese patients (class I-III evaluated together) were satisfied (p < 0.001) [75%, 71%, 75% in obesity classes I, II, and III, respectively (p = 0.43)]. On average, all groups improved by more than the minimal clinically important difference (MCID) in both NRS leg pain (> 3.5) and ODI (> 20). NRS leg pain improved by 4.8 in normal weight patients (95% CI 4.7–4.9), by 4.5 in overweight patients (4.5–4.6) and by 4.3 in obese patients (4.2–4.4) (p < 0.001) [4.4 (4.3–4.6), 3.8 (3.5–4.1) and 4.6 (3.9–5.3) in obesity classes I, II, and III, respectively (p < 0.001)]. The ODI improved by 30 in normal weight patients (30–31), by 29 in overweight patients (28–29) and by 26 in obese patients (25–27) (p < 0.001) [29 (28–29), 25 (22–27) and 27 (22–32) in obesity classes I, II, and III, respectively (p < 0.01)]. A total of 3.0% of normal-weight patients, 3.9% of overweight patients and 3.9% of obese patients suffered complications (p = 0.047) [3.8%, 4.4%, 3.5% in obesity classes I, II, and III, respectively (p = 0.90)].

Conclusions

LDH surgery is also generally associated with favourable outcomes and few complications in patients with morbid obesity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05884-8.

Aortic valve surgery for native valve endocarditis in extreme obesity

Surgical aortic valve replacement represents a class one indication in the setting of aortic valve endocarditis and decompensated heart failure secondary to aortic regurgitation as per the European Society of Cardiology. However, extreme obesity, whereby the body mass index (BMI) >40 kg/m², represents a challenging cohort of patients. Performing cardiac surgery in the bariatric population is fraught with challenges pertaining to intraoperative issues of surgical access and approach. We describe the case of a 45-year-old gentleman who had previous been diagnosed with infective endocarditis of the aortic valve and with a BMI of 68.2 (228 kg). Surgical aortic valve replacement in extreme obesity is associated with deep sternal wound infection, requirement and duration of mechanical ventilation, atrial fibrillation and renal failure. The 'obesity paradox' of overweight and class I obesity (BMI <35) has demonstrated favourable long-term results compared with underweight patients or even those with normal BMI undergoing cardiac surgery.

Postoperative Rhabdomyolysis in the Bilateral Shoulder Areas After Cardiac Surgery

Rhabdomyolysis (RML) is a disease that results from the death of muscle fibers and the release of intracellular contents into the bloodstream as a result of traumatic or non-traumatic muscle injury. Postoperative RML is a rare complication that may result from improper patient positioning, extended surgery time, or unique patient risk factors. We describe a case of a 43-year-old obese male who presented with postoperative bilateral shoulder RML after undergoing cardiothoracic surgery for aortic valve disease. To our knowledge, after a thorough review of the literature using PubMed, Medline, and Google Scholar, no previous studies have reported positioning injuries specific to obese cardiac surgical patients and their relation to RML.

Serum GDF15, a Promising Biomarker in Obese Patients Undergoing Heart Surgery

Background: Obesity is a risk factor that negatively impacts outcomes in patients undergoing heart surgery by mechanisms that are not well-defined nor predicated on BMI alone. This knowledge gap has fuelled a search for biomarkers associated with cardiovascular diseases that could provide clinical insight to surgeons. One such biomarker is growth differentiation factor15(GDF15), associated with inflammation, metabolism, and heart failure outcomes but not yet examined in the context of obesity and cardiac surgery outcomes.

Methods: Patients undergoing open-heart surgery were consented and enrolled for blood and tissue (atria) sampling at the time of surgery. Biomarker analysis was carried out using ELISA and western blot/qPCR, respectively. Biomarker screening was classified by inflammation(NLR, GDF15, Galectin3, ST2, TNFR2), heart failure(HF)/remodeling(NT-proBNP) and metabolism(glycemia, lipid profile). Patients were categorized based on BMI: obese group (BMI ≥30.0) and non-obese group(BMI 20.0–29.9). Subsequent stratification of GDF15 high patients was conservatively set as being in the 75th percentile.

Results: A total of 80 patients undergoing any open-heart surgical interventions were included in the study. Obese (mean BMI = 35.8, n = 38) and non-obese (mean BMI = 25.7, n = 42) groups had no significant differences in age, sex, or co-morbidities. Compared to other biomarkers, plasma GDF15 (mean 1,736 vs. 1,207 ng/l, p < 0.001) was significantly higher in obese patients compared to non-obese. Plasma GDF15 also displayed a significant linear correlation with BMI (R² = 0.097; p = 0.0049). Atria tissue was shown to be a significant source of GDF15 protein and tissue levels significantly correlated with plasma GDF15 (R² = 0.4, p = 0.0004). Obesity was not associated with early/late mortality at median follow-up >2years. However, patients with high GDF15 (>1,580 ng/l) had reduced survival (65%) compared to the remaining patients with lower GDF15 levels (95%) by Kaplan Meier Analysis (median >2 years; p = 0.007).

Conclusions: Circulating GDF15 is a salient biomarker likely sourced from heart tissue that appears to predict higher risk obese patients for adverse outcomes. More importantly, elevated GDF15 accounted for more sensitive outcome association than BMI at 2 years post-cardiac surgery, suggesting it heralds links to pathogenicity and should be actively studied prospectively and dynamically in a post-operative follow-up.

Trial number: NCT03248921.

Operative techniques for improving surgical exposure in basic cardiac surgery

Operative exposure is key to ensuring surgical efficiency and patient safety in cardiac surgery. As the population ages and the prevalence of obesity increases, cardiac surgeons will be challenged to consider obese patient physiology and body habitus, surgical exposure and sternotomy closure techniques, and postoperative medical management to ensure optimal outcomes. In this article, we describe techniques to improve operative exposure in both obese and non-obese patients undergoing basic cardiac surgery and highlight the roles of surgical team members to ensure patient safety and provide optimal anesthetic management. We describe pre-operative techniques regarding incision-site marking and alternative positioning techniques on the operating table to improve visualization and decrease risk of upper extremity injury. We summarized the roles of surgical team members regarding patient positioning, especially in those that are obese, and the challenges associated for anesthesia staff pre- and intraoperatively. Procedural techniques regarding sternotomy management and closure, cannulation, internal mammary harvest, and mitral valve exposure are discussed. Cardiac surgical teams must consider the risks associated with the obese patient population undergoing cardiac surgery procedures and employ techniques pre-, intra-, and postoperatively in a multidisciplinary fashion. Safe and efficacious techniques are paramount to optimal patient outcomes.