Opioids and immune checkpoint inhibitors differentially regulate a common immune network in triple-negative breast cancer

Background

Opioids are the primary analgesics for cancer pain. Recent clinical evidence suggests opioids may counteract the effect of immune checkpoint inhibition (ICI) immunotherapy, but the mechanism for this interaction is unknown. The following experiments study how opioids and immunotherapy modulate a common RNA expression pathway in triple negative breast cancer (TNBC), a cancer subtype in which immunotherapy is increasingly used. This study identifies a mechanism by which opioids may decrease ICI efficacy, and compares ketamine, a non-opioid analgesic with emerging use in cancer pain, for potential ICI interaction.

Methods

Tumor RNA expression and clinicopathologic data from a large cohort with TNBC (N=286) was used to identify RNA expression signatures of disease. Various drug-induced RNA expression profiles were extracted from multimodal RNA expression datasets and analyzed to estimate the RNA expression effects of ICI, opioids, and ketamine on TNBC.

Results

We identified a RNA expression network in CD8+ T-cells that was relevant to TNBC pathogenesis and prognosis. Both opioids and anti-PD-L1 ICI regulated RNA expression in this network, suggesting a nexus for opioid-ICI interaction. Morphine and anti-PD-L1 therapy regulated RNA expression in opposing directions. By contrast, there was little overlap between the effect of ketamine and anti-PD-L1 therapy on RNA expression.

Conclusions

Opioids and ICI may target a common immune network in TNBC and regulate gene expression in opposing fashion. No available evidence supports a similar interaction between ketamine and ICI.

The use of transesophageal echocardiography to predict surgical complexity scoring system for degenerative mitral valve repair

BACKGROUND

For severe mitral valve (MV) degenerative disease, repair is recommended. Prediction of repair complexity and referral to high volume centers can increase rates of successful repair. This study sought to demonstrate that TEE is a feasible imaging modality to predict the complexity of surgical MV repair.

METHODS

Two hundred TEE examinations of patients who underwent MV repair (2009-2011) were retrospectively reviewed and scored by two cardiac anesthesiologists. TEE scores were compared to surgical complexity scores, which were previously assigned based on published methods. Kappa values were reported for the agreement of TEE and surgical scores. McNemar's tests were used to test the homogeneity of the marginal probabilities of different scoring categories.

RESULTS

TEE scores were slightly lower (2[1,3]) than surgical scores (3[1,4]). The agreement was 66% between the scoring methods, with a moderate kappa (.46). Using surgical scores as the gold standard, 70%, 71%, and 46% of simple, intermediate and complex surgical scores, respectively, were correctly scored by TEE. P1, P2, P3, and A2 prolapse were easiest to identify with TEE and had the highest agreement with surgical scoring (P1 agreement 79% with kappa .55, P2 96% [kappa .8], P3 77% [kappa .51], A2 88% [kappa .6]). The lowest agreement between the two scores occurred with A1 prolapse (kappa .05) and posteromedial commissure prolapse (kappa .14). In the presence of significant disagreement, TEE scores were more likely to be of higher complexity than surgical. McNemar's test was significant for prolapse of P1 (p = .005), A1 (p = .025), A2 (p = .041), and the posteromedial commissure (p < .0001).

CONCLUSION

TEE-based scoring is feasible for prediction of the complexity of MV surgical repair, thus allowing for preoperative stratification.

Intraoperative opioids are associated with decreased recurrence rates in colon adenocarcinoma: a retrospective observational cohort study

BACKGROUND

Opioid-induced immunomodulation may be important in colon adenocarcinoma, where tumour DNA mismatch repair (MMR) can determine the level of immune activation with consequences for therapeutic response and prognosis. We evaluated the relationship between intraoperative opioid exposure, MMR subtype, and oncological outcomes after surgery for colon adenocarcinoma.

METHODS

Intraoperative opioid use (standardised by calculating morphine milligram equivalents) during stage I-III colon adenocarcinoma resection was reviewed retrospectively. Tumours were classified as DNA mismatch repair deficient (dMMR) or proficient (pMMR) by immunohistochemistry. The primary outcome was local tumour recurrence, distant tumour recurrence, or both (multivariable analysis). The exposures of interest were intraoperative analgesia and tumour subtype. Opioid-related gene expression was analysed using The Cancer Genome Atlas Colon Adenocarcinoma transcriptomic data.

RESULTS

Clinical and pathological data were analysed from 1157 subjects (median age, 60 [51-70] yr; 49% female) who underwent curative resection for stage I-III colon adenocarcinoma. Higher intraoperative opioid doses were associated with reduced risk of tumour recurrence (hazard ratio=0.92 per 10 morphine milligram equivalents; 95% confidence interval [95% CI], 0.87-0.98; P=0.007), but not with overall survival. In tumours deficient in DNA MMR, tumour recurrence was less likely (HR=0.38; 95% CI, 0.21-0.68; P=0.001), with higher opioid dose associated with eightfold lower recurrence rates. Gene expression related to opioid signalling was different between dMMR and pMMR tumours.

CONCLUSIONS

Higher intraoperative opioid dose was associated with a lower risk of tumour recurrence after surgery for stage I-III colon adenocarcinoma, but particularly so in tumours in which DNA MMR was deficient.

The association between modifiable perioperative parameters and renal function after nephrectomy

OBJECTIVE

To evaluate the association between intraoperative anaesthetic parameters, primarily intraoperative hypotension, and postoperative renal function in patients undergoing nephrectomy.

PATIENTS AND METHODS

We reviewed data from 3240 consecutive patients who underwent nephrectomy between 2010 and 2018. Anaesthetic parameters evaluated included duration of hypotension, tachycardia, hypothermia, volatile anaesthetic use and mean arterial pressure in the post-anaesthesia care unit. Outcomes included acute kidney injury (AKI) and estimated glomerular filtration rate (eGFR) within the first year after nephrectomy. Associations between anaesthetic parameters and outcomes were evaluated with multivariable logistic regression and generalised estimating equation, respectively, adjusted for predictors of renal function after nephrectomy.

RESULTS

Before nephrectomy, 677 (21%) patients had moderate-severe chronic kidney disease. A quarter of patients (n = 809) had postoperative AKI and 35% (n = 746) had Stage ≥3 chronic kidney disease 12-months after surgery. Only 12% of patients (n = 386) had >5 min of intraoperative hypotension. While not statistically significant, longer duration of intraoperative hypotension was associated with slightly higher rates of AKI (odds ratio [OR] per 10-min 1.14, 95% confidence interval [CI] 0.98, 1.32). Prolonged hypothermia was associated with increased rate of AKI (OR per 10-min 1.02, 95% CI 1.00, 1.04), and decreased eGFR (change in eGFR per 10-min -0.19, 95% CI -0.27, -0.12); however, these results have limited clinical significance.

CONCLUSIONS

Under current practice, intraoperative anaesthetic parameters are tightly maintained, restricting the significance of their effect on postoperative renal function. Future studies should evaluate whether haemodynamic parameters during the early postoperative period, when they are monitored less frequently, are associated with renal functional outcome.

ROUTINE USE OF SUGAMMADEX DOES NOT SHORTEN PACU LENGTH OF STAY: A PROSPECTIVE DOUBLE-BLINDED RANDOMIZED CONTROLLED TRIAL

Background

The reversal agent sugammadex has been shown to be more efficacious at reversal from neuromuscular blockade (NMB) induced by the aminosteroid class of non-depolarizing muscle relaxants than the traditionally used medication neostigmine. However, whether these differences lead to significantly faster PACU discharge readiness remains unknown. Given the increased acquisition cost of sugammadex as compared to neostigmine we compared these two reversal agents in our surgical population to determine if its pharmacokinetic superiority warranted a change in current practice.

Methods

We conducted a single-center randomized patient and assessor blinded clinical trial. A total of 201 patients presenting for surgery requiring NMB with an estimated duration of ≤ 6 hours were included in the intention-to-treat (ITT) analysis. The primary outcome was time from reversal agent administration to PACU discharge readiness, measured by either the institutional discharge scoring tool or bedside clinical assessment by a PACU physician or advanced practice provider. Secondary outcomes included subjective assessment of recovery by the patient (pain, visual changes, speaking difficulty, swallowing difficulty, PONV, anxiety) and a simple strength assessment.

Results

Median time from reversal administration to PACU discharge readiness was 3.59 hours (IQR 2.49-5.09) in the neostigmine group and 3.62 hours (IQR 2.70-5.87) in the sugammadex group. Patients who received sugammadex had 8% longer reversal to PACU discharge times (exp(estimate) 1.08, 95% CI [0.87-1.34], p=0.499). Patients age 70 or older had 28% longer reversal to PACU discharge times (exp(estimate) of 1.28, 95% CI [0.91-1.80], P=0.158). In the a modified ITT analysis, sugammadex patients were estimated to be in PACU 13% longer than neostigmine arm patients (exp(estimate) 1.13, 95% CI [0.91-1.40], p=0.265) and patients older than or equal to 70 years 31% longer than patients less than 70 years old (exp(estimate) 1.31, 95% CI [0.93-1.84], p=0.121). Treatment arm was not associated with any of the secondary outcomes.

Conclusion

There was no significant difference in time to readiness to discharge from PACU, and there were no subjective or objective clinically relevant differences in recovery from neuromuscular blockade between the groups. Findings of this study support continued use of either agent at the anesthesiologist's discretion.

Intraoperative opioid exposure, tumour genomic alterations, and survival differences in people with lung adenocarcinoma

BACKGROUND

Opioids have been linked to worse oncologic outcomes in surgical patients. Studies in certain cancer types have identified associations between survival and intra-tumoural opioid receptor gene alterations, but no study has investigated whether the tumour genome interacts with opioid exposure to affect survival. We sought to determine whether intraoperative opioid exposure is associated with recurrence-specific survival and overall survival in early-stage lung adenocarcinoma, and whether selected tumour genomics are associated with this relationship. Associations between ketamine and dexmedetomidine and outcomes were also studied.

METHODS

Surgical patients (N=740) with pathological stage I-III lung adenocarcinoma and next-generation sequencing data were retrospectively reviewed from a prospectively maintained database.

RESULTS

On multivariable analysis, ketamine administration was protective for recurrence-specific survival (hazard ratio = 0.44, 95% confidence interval 0.24-0.80; P=0.007), compared with no adjunct. Higher intraoperative oral morphine milligram equivalents were significantly associated with worse overall survival (hazard ratio=1.09/10 morphine milligram equivalents, 95% confidence interval 1.02-1.17; P=0.010). Significant interaction effects were found between morphine milligram equivalents and fraction genome altered and morphine milligram equivalents and CDKN2A, such that higher fraction genome altered or CDKN2A alterations were associated with worse overall survival at higher morphine milligram equivalents (P=0.044 and P=0.052, respectively). In contrast, alterations in the Wnt (P=0.029) and Hippo (P=0.040) oncogenic pathways were associated with improved recurrence-specific survival at higher morphine milligram equivalents, compared with unaltered pathways.

CONCLUSIONS

Intraoperative opioid exposure is associated with worse overall survival, whereas ketamine exposure is associated with improved recurrence-specific survival in patients with early-stage lung adenocarcinoma. This is the first study to investigate tumour-specific genomic interactions with intraoperative opioid administration to modify survival associations.

Intraoperative haemodynamics and postoperative intensive care unit admission in older patients with cancer

PURPOSE

Research on the impact of various intraoperative haemodynamic variables on the incidence of postoperative ICU admission among older patients with cancer is limited. In this study, the relationship between intraoperative haemodynamic status and postoperative intensive care unit admission among older patients with cancer is explored.

METHODS

Patients aged ≥75 who underwent elective oncologic surgery lasting ≥120min were analysed. Chi-squared and t-tests were used to assess the associations between intraoperative variables with postoperative intensive care unit admission. Multivariable regressions were used to analyse potential predict risk factors for postoperative intensive care unit admission.

RESULTS

Out of 994 patients, 48 (4.8%) were admitted to the intensive care unit within 30 days following surgery. Intensive care unit admission was associated with the presence of ≥4 comorbid conditions, intraoperative blood loss ≥100mL, and intraoperative tachycardia and hypertensive urgency. On multivariable analysis, operation time ≥240min (Odds Ratio [OR] = 2.29, p = 0.01), and each minute spent with intraoperative hypertensive urgency (OR = 1.06, p = 0.01) or tachycardia (OR = 1.01, p = 0.002) were associated with postoperative intensive care unit admission.

CONCLUSION

Intraoperative hypertensive urgency and tachycardia were associated with postoperative intensive care unit admission in older patients undergoing cancer surgery.

Identifying Clear Cell Renal Cell Carcinoma Coexpression Networks Associated with Opioid Signaling and Survival

While opioids constitute the major component of perioperative analgesic regimens for surgery in general, a variety of evidence points to an association between perioperative opioid exposure and longer term oncologic outcomes. The mechanistic details underlying these effects are not well understood. In this study, we focused on clear cell renal cell carcinoma (ccRCC) and utilized RNA sequencing and outcome data from both The Cancer Genome Atlas, as well as a local patient cohort to identify survival-associated gene coexpression networks. We then projected drug-induced transcriptional profiles from in vitro cancer cells to predict drug effects on these networks and recurrence-free, cancer-specific, and overall survival. The opioid receptor agonist, leu-enkephalin, was predicted to have antisurvival effects in ccRCC, primarily through Th2 immune- and NRF2-dependent macrophage networks. Conversely, the antagonist, naloxone, was predicted to have prosurvival effects, primarily through angiogenesis, fatty acid metabolism, and hemopoesis pathways. Eight coexpression networks associated with survival endpoints in ccRCC were identified, and master regulators of the transition from the normal to disease state were inferred, a number of which are linked to opioid pathways. These results are the first to suggest a mechanism for opioid effects on cancer outcomes through modulation of survival-associated coexpression networks. While we focus on ccRCC, this methodology may be employed to predict opioid effects on other cancer types and to personalize analgesic regimens in patients with cancer for optimal outcomes. SIGNIFICANCE: This study suggests a possible molecular mechanism for opioid effects on cancer outcomes generally, with implications for personalization of analgesic regimens.

Using near-infrared spectroscopy myocardial oximetry to monitor myocardial oxygen balance in a swine model of cardiac surgery: a descriptive study

Monitoring of the adequacy of myocardial protection with cardioplegia is nearly non-existent in clinical cardiac surgical practice and instead relies on well-defined protocols for delivery of cardioplegia often resulting in inadequate protection. We hypothesized that Near Infrared Spectroscopy technology could be useful in the monitoring of the myocardial oxygen state by attaching the monitors to the epicardium in a porcine model of cardiac surgery. The experiments were conducted with 3 different protocols of 2 pigs each for a total of 6 pigs. The objective was to induce episodic, oxygen supply-demand mismatch. Methods for decreased supply included decreasing coronary blood flow, coronary blood hypoxemia, coronary occlusion, hypovolemia, and hypotension. Methods for increase demand included rapid ventricular pacing and the administration of isoproterenol. Changes in myocardial tissue oximetry were measured and this measurement was then correlated with blood hemoglobin saturations of oxygen from coronary sinus blood samples. We found that decreases in myocardial oxygen supply or increases in demand due to any of the various experimental conditions led to decreases in both myocardial tissue oximetry and hemoglobin oxygen saturation of coronary sinus blood with recovery when the conditions were returned to baseline. Correlation between myocardial tissue oximetry and hemoglobin oxygen saturation of coronary sinus blood was moderate to strong under all tested conditions. This may have translational applications as a monitor of adequacy of myocardial protection and the detection of coronary occlusion.

Acute Hemodynamic Compromise following Superior Vena Cava Stent Placement: A Case Report

Symptomatic relief of Superior Vena Cava (SVC) syndrome caused by tumor obstruction is achieved by the placement of a percutaneous superior vena cava stent. Complications are rare. Even more uncommon is acute hemodynamic compromise from acute hemopericardium during placement of an SVC stent. Point of Care Ultrasound (POCUS) in the Interventional Radiology Suite (IR) suite allows for rapid diagnosis and guidance of pericardial drainage and hemodynamic management.

Institution of Monthly Anesthesia Quality Reports Does Not Reduce Postoperative Complications despite Improved Metric Compliance

While quality programs have been shown to improve provider compliance, few have demonstrated conclusive improvements in patient outcomes. We hypothesized that there would be increased metric compliance and decreased postoperative complications after initiation of an anesthesiology quality improvement program at our institution. We performed a retrospective study of all adult inpatients having anesthesia for a twelve-month period that spanned six months before and after program implementation. The primary outcome was the rate of complications in the post-implementation period. Secondary outcomes included the change in proportion of complications and compliance with quality metrics. We studied a total of 9620 adult inpatient cases, subdivided into pre- and post-implementation groups (4832 vs 4788.) After multivariate model adjustment, the rate of any complication (our primary outcome) was not significantly changed (32% to 31%; adjusted P = 0.410.) Of the individual complications, only wound infection (2.0% to 1.5%; adjusted P = 0.020) showed a statistically significant decrease. Statistically and clinically significant increases in compliance were seen for the BP-02 Avoiding Monitoring Gaps metric (81% to 93%, P < 0.001), both neuromuscular blockade metrics (NMB-01 76% to 91%, P < 0.001; NMB-02 95% to 97%, P = 0.006), both tidal volume metrics (PUL-01 84% to 93%, P < 0.001; PUL-02 30% to 45%, P < 0.001), and the TEMP-02 Core Temperature Measurement metric (88% to 94%, P < 0.001). Implementation of a comprehensive quality feedback program improved metric compliance but was not associated with a change in postoperative complications.

Use of vasopressors during esophagectomy is not associated with increased risk of anastomotic leak

Vasopressor use during esophagectomy has been reported to increase the risk of postoperative anastomotic leak and associated morbidity. We sought to assess the association between vasopressor use and fluid (crystalloid and colloid) administration and anastomotic leak following open esophagectomy. Patients who underwent open Ivor Lewis esophagectomy were identified from a prospective institutional database. The primary outcome was postoperative anastomotic leak (any grade) and analyzed using logistic regression models. Postoperative anastomotic leak developed in 52 of 327 consecutive patients (16%) and was not significantly associated with vasopressor use or fluid administered in either univariable or multivariable analyses. Increasing body mass index was the only significant characteristic of both univariable (P = 0.004) and multivariable analyses associated with anastomotic leak (odds ratio, 1.05; 95% confidence interval, 1.01-1.09; P = 0.007). Of the 52 patients that developed an anastomotic leak, 12 (23%) were grade 1, 21 (40%) were grade 2 and 19 (37%) were grade 3. In our cohort, only body mass index, and not intraoperative vasopressor use and fluid administration, was significantly associated with increased odds of postoperative anastomotic leak following open Ivor Lewis esophagectomy.

Pericardial Effusions in Patients With Cancer: Anesthetic Management and Survival Outcomes

OBJECTIVES

The objective of this study was to describe practice patterns of anesthetic management during pericardial window creation.

DESIGN

Retrospective observational cohort study.

SETTING

Single tertiary cancer center.

PARTICIPANTS

A total of 150 patients treated for cancer between 2011 and 2015 were included in the study.

MEASUREMENTS AND MAIN RESULTS

The primary objective was to evaluate anesthetic management in pericardial window creation. Secondary outcomes were 30-day mortality and overall survival after pericardial window creation. Thirty-day mortality was 19.3%, and median survival was 5.84 months. Higher American Society of Anesthesiologists (ASA) physical status of patients was associated with preinduction arterial line placement (51% ASA 3 v 79% ASA 4; p = 0.002) and use of etomidate for anesthetic induction (34% ASA 3 v 60% ASA 4; p = 0.003). However, there was no association between anesthetic management and presence of tamponade in these patients. Cardiac aspirate volume (per 10 mL: odds ratio [OR], 1.02 [95% CI, 1.0-1.04]; p = 0.026) and intraoperative arrhythmia (atrial fibrillation: OR, 6.76 [95% CI, 1.2-37.49]; p = 0.029; sinus tachycardia: OR, 4.59 [95% CI, 1.25-16.90]; p = 0.022) were associated independently with increased 30-day mortality. High initial heart rate (per 10 beats per minute: hazard ratio [HR], 1.18 [95% CI, 1.05-1.33]; p = 0.005) in the operating room and intraoperative sinus tachycardia (HR, 1.86 [95% CI, 1.15-3.03]; p = 0.012) were associated independently with worse overall survival.

CONCLUSION

Risk of death after pericardial window creation remains high in patients with cancer. Variations in anesthetic management did not affect survival in oncologic patients with pericardial effusions.

The Association of Cerebral Desaturation During One-Lung Ventilation and Postoperative Recovery: A Prospective Observational Cohort Study

OBJECTIVES

This study was designed to investigate whether cerebral oxygen desaturations during thoracic surgery are predictive of patients' quality of recovery. As a secondary aim, the authors investigated the relationship among cerebral desaturations and postoperative delirium and hospital length of stay.

DESIGN

This study was a prospective observational cohort study.

SETTING

A single tertiary-care medical center from September 2012 through March 2014.

PATIENTS

Adult patients scheduled for elective pulmonary surgery requiring one-lung ventilation.

INTERVENTIONS

All patients were monitored with the ForeSight cerebral oximeter.

MEASUREMENTS AND MAIN RESULTS

The primary assessment tool was the Postoperative Quality of Recovery Scale. Delirium was assessed using the Confusion Assessment Method. Of the 117 patients analyzed in the study, 60 of the patients desaturated below a cerebral oximetry level of 65% for a minimum of 3 minutes (51.3%). Patients who desaturated were significantly less likely to have cognitive recovery in the immediate postoperative period (p = 0.012), which did not persist in the postoperative period beyond day 0. Patients who desaturated also were more likely to have delirium (p = 0.048, odds ratio 2.81 [95% CI 1.01-7.79]) and longer length of stay (relative duration 1.35, 95% CI 1.05-1.73; p = 0.020).

CONCLUSIONS

Intraoperative cerebral oxygen desaturations, frequent during one-lung ventilation, are associated significantly with worse early cognitive recovery, high risk of postoperative delirium, and prolonged length of stay. Large interventional studies on cerebral oximetry in the thoracic operating room are warranted.

COVID-19 in the Cancer Patient

The novel coronavirus disease 2019 (COVID-19) was first reported in China in December 2019. Since then, it has spread across the world to become one of the most serious life-threatening pandemics since the influenza pandemic of 1918. This review article will focus on the specific risks and nuanced considerations of COVID-19 in the cancer patient. Important perioperative management recommendations during this outbreak are emphasized, in addition to discussion of current treatment techniques and strategies available in the battle against COVID-19.

Association of intraoperative opioids with improved recurrence-free survival in triple-negative breast cancer

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Background: Opioid-induced immunomodulation may be of particular importance in triple negative breast cancer (TNBC) where an immune response is associated with improved outcome and response to immunotherapy. We evaluated the association between intraoperative opioids and outcomes in a large TNBC cohort. Methods: Consecutive patients with stage I-III primary TNBC treated between 03/2010 and 12/2016 were identified from our prospectively maintained database. Total intraoperative opioid dose was extracted from anesthetic records and converted to oral morphine milligram equivalents (MME) (10 MME = 50 mcg fentanyl IV). Univariable and multivariable (MVA) Cox proportional hazards analysis (adjusting for relevant clinicopathological features, (neo)adjuvant therapy, anesthesia technique and morbidity score), were performed to quantify the association between opioid exposure and recurrence-free survival (RFS) and overall survival (OS). Results: 1143 patients were included. Median age was 54 years (IQR 45, 64). 911 (80%) had ductal histology, 359 (31%) had nodal metastases, and 1070 (94%) were poorly differentiated. 781 (68%) received adjuvant chemotherapy and 313 (27%) received neoadjuvant chemotherapy. 525 (46%) received total intravenous anesthesia and 618 (54%) had general anesthesia. Median intraoperative opioid dose was 30 MME (IQR 20, 60). 5-year RFS was 81% (95% CI 79%-84%), 5-year OS was 86% (95% CI 84%-88%). In MVA, higher opioid administration was associated with favorable RFS but did not significantly affect OS (Table). Conclusions: Our study is the first to directly evaluate intraoperative opioid administration in TNBC and suggests a protective effect on RFS. Future work will focus on elucidating the underlying mechanism for this effect, including possible modulation of endogenous opioid signaling pathways and immunologic correlates. [Table: see text]

Focused Transesophageal Echocardiography for Bedside Diagnosis of Iatrogenic Cardiac Perforation: A Case Report

We describe an extremely rare complication of chest tube placement and focused transesophageal echocardiography (TEE) in the diagnosis of a life-threatening condition. It illustrates the value and utility of point-of-care ultrasound (POCUS) by way of a focused TEE in confirming a diagnosis and contributing toward the expeditious operative management of a life-threatening scenario. POCUS continues to gain traction in the field of anesthesiology. However, incorporation of POCUS training into curriculum of anesthesia residency programs is still in the infancy stages. Our report demonstrates the need for development and standardization of POCUS training for anesthesiologists in the perioperative setting.

Immune checkpoint inhibitors: a narrative review of considerations for the anaesthesiologist

Immunotherapy has revolutionised the treatment of oncologic malignancies. Immune checkpoint inhibitors represent a new class of immunotherapy drugs. Although these drugs show promise, they are associated with immune-related adverse reactions. An increasing number of patients who undergo surgery will have had treatment with immune checkpoint inhibitors. In this narrative review article, we discuss their mechanism of action, therapeutic effects, pertinent toxicities, and address specific perioperative considerations for patients treated with immune checkpoint inhibitors.

Next Generation of Cancer Treatments: Chimeric Antigen Receptor T-Cell Therapy and Its Related Toxicities: A Review for Perioperative Physicians

Cancer immunotherapy has entered a new era with the recent introduction of genetically engineered T-cells that express chimeric antigen receptors (CARs) capable of recognizing and destroying tumor cells. Several clinical trials in patients with relapsed or refractory B-cell malignancies have demonstrated complete remission rates ranging from 50% to 90%, with long-term data suggestive of a possible curative response. CAR T-cell therapy is currently under investigation for earlier use in these disease processes and in various other solid and liquid tumors. CAR T-cell therapy is associated with a unique postinfusion toxicity profile including cytokine-release syndrome and neurotoxicity. These toxicities are usually reversible but can be fatal, requiring close vigilance and prompt treatment often in an intensive care unit (ICU) setting. CAR T-cell therapy is currently restricted to designated centers possessing expertise in acute toxicity management, but wider use is likely if early therapeutic successes are replicated. As perioperative and critical care physicians, anesthesiologists may encounter such patients in the perioperative or ICU setting and should become familiar with this unique and novel therapeutic modality capable of causing extreme cardiovascular and respiratory compromise. This review will describe the immunobiology of CAR T-cells, their relevance to cancer treatment, clinical aspects of their therapeutic use in cancer chemotherapy, toxicities related to CAR T-cell use, and their therapeutic management.

Short-term safety and effectiveness of sugammadex for surgical patients with end-stage renal disease: a two-centre retrospective study

Sugammadex is a novel reversal agent for aminosteroid neuromuscular blocking drugs, especially rocuronium. Given its renal excretion, sugammadex is not recommended for patients with end-stage renal disease; however, reports exist of its use in this group of patients. This two-institutional retrospective observational study aimed to review the safety profile and effectiveness of sugammadex in surgical patients with end-stage renal disease who required pre-operative renal replacement therapy. Adult surgical patients with end-stage renal disease requiring pre-operative renal replacement therapy, who received sugammadex between April 2016 and January 2019, were studied. The primary outcome was the incidence of postoperative tracheal re-intubation within 48 h. The secondary outcome was the incidence of deferred tracheal extubation in the operating theatre. One hundred and fifty-eight patients were identified from 125,653 surgical patients: 48 patients (30%) underwent renal transplantation and 110 (70%) underwent non-renal transplantation procedures. There were 22 instances (14%) of deferred tracheal extubation due to surgical and/or pre-existing medical conditions. Out of the 136 patients who had the tracheal tube removed at the end of the procedure, three patients had their trachea re-intubated within 48 h: two patients developed pulmonary oedema resulting from volume overload; and one patient had worsening sepsis. No incidence of recurrence of neuromuscular blockade was observed. Of note, 24 (18%) patients were found to have incomplete neuromuscular blockade reversal with neostigmine but administration of sugammadex led to successful tracheal extubation. In conclusion, sugammadex appears to be safe and effective in adult patients with end-stage renal disease receiving pre-operative renal replacement therapy.

Identification of Abundant and Evolutionarily Conserved Opioid Receptor Circular RNAs in the Nervous System Modulated by Morphine

Circular RNAs (circRNAs) are a distinct category of single-stranded, covalently closed RNAs formed by backsplicing. The functions of circRNAs are incompletely known and are under active investigation. Here, we report that in addition to traditional linear mRNAs (linRNA), mouse, rat, and human opioid receptor genes generate exonic circRNA isoforms. Using standard molecular biologic methods, Oprm1 circRNAs (circOprm1) were detected in RNAs of rodent and human brains and spinal cords, as well as human neuroblastoma cells, suggesting evolutionary conservation. Sequencing confirmed backsplicing using canonical splice sites. Oprm1 circRNAs were sense-stranded circRNAs resistant to RNase R digestion. The relative abundance of Oprm1 circRNA to linRNA determined by quantitative reverse transcription polymerase chain reaction varied among mouse brain regions, with circRNA isoforms predominating in rostral structures and less abundant in brain stem. Chronic morphine exposure in mice increased brain circOprm1e2.3 and circOprm1.e2.e3.e4(302) levels by 1.5- to 1.6-fold relative to linRNA. Sequence analysis predicted numerous microRNA binding sites within Oprm1 circRNA sequences, suggesting a potential role in microRNA sequestration through sponging. In addition, we observed that other opioid receptor genes including δ, κ, and nociceptin receptor genes produced similar circRNAs. In conclusion, all members of the opioid receptor gene family express circRNAs, with Oprm1 circRNA levels exceeding those of linear forms in some regions. SIGNIFICANCE STATEMENT: The modulation of Oprm1 circular RNA (circRNA) expression by morphine, coupled with the high abundance and existence of potential miRNA binding sites with circRNA sequences suggests the potential role of Oprm1 circRNAs in chronic opioid effects such as tolerance.

Xpert(®) MTB/RIF detection of Mycobacterium tuberculosis from sputum collected in molecular transport medium

BACKGROUND

The Xpert(®) MTB/RIF assay is widely used for Mycobacterium tuberculosis detection. However, specimen transport remains a challenge. PrimeStore Molecular Transport Medium(®) (PS-MTM) inactivates specimens and stabilizes DNA/RNA at ambient temperature for subsequent molecular detection.

OBJECTIVE

To compare the detection of M. tuberculosis concentrations in PS-MTM using Xpert and real-time polymerase chain reaction (RT-PCR), and smear-positive sputum specimens collected using a flocked swab.

METHODS

Dilutions of M. tuberculosis in PS-MTM and phosphate buffered saline (PBS) were analyzed using the Xpert assay and commercial RT-PCR. Smear-positive (1+ to 3+) sputum specimens (n = 17) were transferred by flocked swab into PS-MTM and PBS, and were compared to standard 1.0 ml sputum Xpert analysis.

RESULTS

Using the Xpert assay, cycle threshold values from high M. tuberculosis concentrations in PS-MTM (>10(3) colony forming units [cfu]/ml) were increased compared to control. In contrast, M. tuberculosis samples containing <10(3) cfu/ml, i.e., low concentrations, suspended in PS-MTM resulted in detection down to 10 cfu/ml. Xpert detection efficiency in PS-MTM treated samples (63.2%) was improved compared to PBS controls (34.9%). Xpert detected M. tuberculosis in all sputum specimens collected by flocked swabs in PS-MTM, and correlated with routine Xpert detection.

CONCLUSIONS

PS-MTM enhances M. tuberculosis detection at low concentrations of M. tuberculosis, and provides a simplified and efficient collection method for Xpert detection.

Heparin-Induced Thrombocytopenia: A Comprehensive Clinical Review

Heparin-induced thrombocytopenia is a profoundly dangerous, potentially lethal, immunologically mediated adverse drug reaction to unfractionated heparin or, less commonly, to low-molecular weight heparin. In this comprehensive review, the authors highlight heparin-induced thrombocytopenia's risk factors, clinical presentation, pathophysiology, diagnostic principles, and treatment. The authors place special emphasis on the management of patients requiring procedures using cardiopulmonary bypass or interventions in the catheterization laboratory. Clinical vigilance of this disease process is important to ensure its recognition, diagnosis, and treatment. Misdiagnosis of the syndrome, as well as misunderstanding of the disease process, continues to contribute to its morbidity and mortality.

Perioperative Interventions to Modify Risk of Morbidity and Mortality

Perioperative myocardial ischemia is the single most important, potentially reversible risk factor for mortality and cardiovascular complications during and after noncardiac surgery. The influence of anesthetic choices and techniques on cardiac risk in noncardiac surgery is difficult to ascertain because of the low incidence of morbid cardiac outcomes in the surgical population as a whole. This article summarizes several areas (eg, perioperative βblockade, glucose management, and perioperative hemodynamics) that have been addressed in well-designed clinical trials.

Molecular detection of Mycobacterium tuberculosis from sputum transported in PrimeStore(®) from rural settings

SETTING

Mopani District, South Africa.

OBJECTIVE

To explore remote, molecular detection of Mycobacterium tuberculosis from sputum transported using PrimeStore(®) Molecular Transport Medium (PS-MTM) compared to settings where microscopy or Xpert(®) MTB/RIF is used as the baseline test.

DESIGN

Two sputum specimens were collected from patients with cough of ⩾ 2 weeks at clinics in rural South Africa. Shortly after expectoration and before processing using Xpert, microscopy and liquid culture, a flocked swab was swirled in each of these specimens and placed in PS-MTM. Swabs were stored and transported to the United States at ambient temperature for real-time PrimeMix(®) polymerase chain reaction (PM-PCR).

RESULTS

Of 132 patients, 23 (17%) were positive on microscopy, 39 (30%) on Xpert and 44 (33%) by PS-MTM/PM-PCR. Concordance of PS-MTM/PM-PCR with positive microscopy and Xpert was respectively 96% and 85%. Of 107 microscopy-negative samples, 22 (21%) were positive using PS-MTM/PM-PCR, while 11/91 (12%) Xpert-negative samples were PS-MTM/PM-PCR-positive. PS-MTM/PM-PCR positivity was significantly higher than smear microscopy positivity (P < 0.001), but similar to Xpert (P = 0.33).

CONCLUSION

PCR testing of specimens transported in PS-MTM would enhance TB diagnosis in settings where smear microscopy is the baseline diagnostic test, and could provide an alternative in settings where Xpert testing is not available.

Cerebral oximetry monitoring during sinus endoscopy

OBJECTIVES/HYPOTHESIS

Deliberate hypotension, reverse Trendelenburg position, and hyperventilation are techniques utilized during functional endoscopic sinus surgery to attempt to reduce surgical bleeding. These methods may predispose patients to cerebral ischemia. Cerebral oximetry has not been investigated extensively within otolaryngologic surgery. Our study sought to address the question of whether cerebral oximetry is feasible in the FESS population and evaluate whether the data provided may be useful in the assessment of cerebral perfusion.

STUDY DESIGN

Prospective, blinded, observational trial.

METHODS

We designed a prospective, blinded, observational trial of patients undergoing functional endoscopic sinus surgery using cerebral oximetry monitoring. Collected data included mean arterial blood pressure (MAP), end-tidal carbon dioxide (EtCO₂), cerebral saturation (SctO₂), postanesthesia care unit (PACU) length of stay, and incidence of postoperative nausea and vomiting (PONV).

RESULTS

Thirty-one subjects were enrolled into the study. Univariate analyses showed cross-correlation between concurrent EtCO₂ values and SctO₂ of 0.43 (95% CI: 0.27 to 0.59) and between present EtCO₂ and the SctO₂ 5 minutes later of 0.46 (95% CI: 0.33 to 0.59). MAP was not significantly cross-correlated with SctO₂. Patients who had an SctO₂ below 60% at any time had a median (interquartile range [IQR]) PACU length of stay of 167 (IQR, 95-386) minutes. Patients whose cerebral saturation did not fall below 60% at any time had a median PACU length of stay of 103 (IQR, 76-155) minutes. This difference did not reach statistical significance (P = .257). The median (IQR) maximum decline in SctO₂ for patients with PONV was 11.2% (IQR, 8.2%-13.1%) and for patients without PONV was 7.1% (IQR, 5.1%-9.8%) (P = .126).

CONCLUSIONS

Cerebral oximetry monitoring was feasible during functional endoscopic sinus surgery. This study demonstrated a cross-correlation between EtCO₂ and SctO₂, but not MAP and SctO₂. A longer PACU length of stay and higher rate of PONV were seen but did not reach statistical significance.

Low intraoperative tidal volume ventilation with minimal PEEP is associated with increased mortality

Background

Anaesthetists have traditionally ventilated patients’ lungs with tidal volumes (TVs) between 10 and 15 ml kg⁻¹ of ideal body weight (IBW), without the use of PEEP. Over the past decade, influenced by the results of the Acute Respiratory Distress Syndrome Network trial, many anaesthetists have begun using lower TVs during surgery. It is unclear whether the benefits of low TV ventilation can be extended into the perioperative period.

Methods

We reviewed the records of 29 343 patients who underwent general anaesthesia with mechanical ventilation between January 1, 2008 and December 31, 2011. We calculated TV kg⁻¹ IBW, PEEP, peak inspiratory pressure (PIP), and dynamic compliance. Cox regression analysis with propensity score matching was performed to examine the association between TV and 30-day mortality.

Results

Median TV was 8.6 [7.7–9.6] ml kg⁻¹ IBW with minimal PEEP [4.0 (2.2–5.0) cm H₂O]. A significant reduction in TV occurred over the study period, from 9 ml kg⁻¹ IBW in 2008 to 8.3 ml kg⁻¹ IBW in 2011 (P=0.01). Low TV 6–8 ml kg⁻¹ IBW was associated with a significant increase in 30-day mortality vs TV 8–10 ml kg⁻¹ IBW: hazard ratio (HR) 1.6 [95% confidence interval (CI) [1.25–2.08], P=0.0002]. The association remained significant after matching: HR 1.63 [95% CI (1.22–2.18), P<0.001]. There was only a weak correlation between TV kg⁻¹ IBW and dynamic compliance (r=−0.006, P=0.31) and a weak-to-moderate correlation between TV kg⁻¹ IBW and PIP (r=0.32 P<0.0001).

Conclusions

Use of low intraoperative TV with minimal PEEP is associated with an increased risk of 30-day mortality.

Vocal cord paralysis after aortic surgery

OBJECTIVE

The purpose of this study was to investigate variables associated with vocal cord paralysis during complex aortic procedures.

DESIGN

A retrospective review.

SETTING

A tertiary care center.

PARTICIPANTS

Four hundred ninety-eight patients who underwent aortic surgery between 2002 and 2007.

METHODS

Two groups were studied. Group A patients had procedures only involving their aortic root and/or ascending aorta. Group B patients had procedures only involving their aortic arch and/or descending aorta.

RESULTS

The incidence of vocal cord paralysis was higher (7.26% v 0.8%) in group B patients (p < 0.0001). Increasing the duration of cardiopulmonary bypass time was associated with an increased risk of vocal cord paralysis and death in both groups A and B (p = 0.0002 and 0.002, respectively). Additionally, within group B, descending aneurysms emerged as an independent risk factor associated with vocal cord paralysis (p = 0.03). Length of stay was statistically significantly longer among group A patients who suffered vocal cord paralysis (p = 0.017) and trended toward significance in group B patients who suffered vocal cord paralysis (p = 0.059). The association between tracheostomy and vocal cord paralysis among group A patients reached statistical significance (p = 0.007) and trended toward significance in group B patients (p = 0.057).

CONCLUSIONS

Increasing duration of cardiopulmonary bypass time was associated with a higher risk of vocal cord paralysis in patients undergoing aortic surgery. Additionally, within group B patients, descending aortic aneurysm was an independent risk factor associated with vocal cord paralysis. Most importantly, vocal cord paralysis appeared to have an association between an increased length of stay and tracheostomy among a select group of patients undergoing aortic surgery.