Effects of Intra-operative Cardiopulmonary Variability On Post-operative Pulmonary Complications in Major Non-cardiac Surgery: A Retrospective Cohort Study.

Intraoperative cardiopulmonary variables are well-known predictors of postoperative pulmonary complications (PPC), traditionally quantified by median values over the duration of surgery. However, it is unknown whether cardiopulmonary instability, or wider intra-operative variability of the same metrics, is distinctly associated with PPC risk and severity. We leveraged a retrospective cohort of adults (n = 1202) undergoing major non-cardiothoracic surgery. We used multivariable logistic regression to evaluate the association of two outcomes (1)moderate-or-severe PPC and (2)any PPC with two sets of exposure variables- (a)variability of cardiopulmonary metrics (inter-quartile range, IQR) and (b)median intraoperative cardiopulmonary metrics. We compared predictive ability (receiver operating curve analysis, ROC) and parsimony (information criteria) of three models evaluating different aspects of the intra-operative cardiopulmonary metrics: Median-based: Median cardiopulmonary metrics alone, Variability-based: IQR of cardiopulmonary metrics alone, and Combined: Medians and IQR. Models controlled for peri-operative/surgical factors, demographics, and comorbidities. PPC occurred in 400(33%) of patients, and 91(8%) experienced moderate-or-severe PPC. Variability in multiple intra-operative cardiopulmonary metrics was independently associated with risk of moderate-or-severe, but not any, PPC. For moderate-or-severe PPC, the best-fit predictive model was the Variability-based model by both information criteria and ROC analysis (area under the curve, AUCVariability-based = 0.74 vs AUCMedian-based = 0.65, p = 0.0015; AUCVariability-based = 0.74 vs AUCCombined = 0.68, p = 0.012). For any PPC, the Median-based model yielded the best fit by information criteria. Predictive accuracy was marginally but not significantly higher for the Combined model (AUCCombined = 0.661) than for the Median-based (AUCMedian-based = 0.657, p = 0.60) or Variability-based (AUCVariability-based = 0.649, p = 0.29) models. Variability of cardiopulmonary metrics, distinct from median intra-operative values, is an important predictor of moderate-or-severe PPC.

Correlations of Opioid Intake During Different Predischarge Time Frames with Postdischarge Opioid Use Following Inpatient Surgery.

Previous work has shown that predischarge opioid use is the most reliable and practical predictor of postdischarge opioid intake after inpatient surgery. However, the most appropriate predischarge time frame for operationalizing this relationship into more individualized prescriptions is unknown. We compared the correlations between the quantity of opioids taken during 5 predischarge time frames and self-reported postdischarge opioid intake in 604 adult surgery patients. We found that the 24-hour predischarge time frame was most strongly correlated (ρ= 0.60, P < .001) with postdischarge opioid use and may provide actionable information for predicting opioid use after discharge.

Comparison of postoperative mobilization measurements by activPAL versus Johns Hopkins Highest Level of Mobility scale after major abdominal surgery.

BACKGROUND: The Johns Hopkins Highest Level of Mobility scale is a validated tool for assessing patient mobility in the hospital. It has excellent inter-rater and test-retest reliabilities, but it is unknown how accurately Johns Hopkins Highest Level of Mobility documentation reflects the patients' mobility performance in the immediate postoperative period compared to objective measures such as accelerometers. METHODS: In this single-center observational study, consented adults undergoing open abdominal surgery wore a research-grade accelerometer, activPAL, starting immediately postoperatively until hospital discharge or up to 7 days. We collected the Johns Hopkins Highest Level of Mobility scores documented by hospital staff via retrospective chart review and evaluated their accuracy in describing the type, frequency, and volume of postoperative out-of-bed mobilization using the activPAL as the criterion. RESULTS: We analyzed data from 56 participants. The activPAL showed that participants spent 97.7% of their time lying in bed or sitting in a chair. Meanwhile, the Johns Hopkins Highest Level of Mobility documentation of preambulatory activities (scores 1-5) was rare. The activPAL detected 4 times more out-of-bed mobilization than routine Johns Hopkins Highest Level of Mobility documentation. Whereas the frequency of activPAL-measured out-of-bed mobilization increased steadily to a median of 9 sessions by postoperative day 6, the number of Johns Hopkins Highest Level of Mobility documentation remained around twice daily. ActivPAL measurements demonstrated that Johns Hopkins Highest Level of Mobility documentation of ambulatory sessions (scores 6-8) was accurate. CONCLUSIONS: We found that routine Johns Hopkins Highest Level of Mobility documentation did not accurately detect preambulatory activities or the overall frequency of out-of-bed mobility sessions, poorly reflecting the highly sedentary behaviors of the acute postoperative inpatients and highlighting the need to improve clinical documentation or use alternative methods to track postoperative mobilization.

The in-vitro influence of urea concentration on thromboelastrography in patients with and without end stage renal disease.

BACKGROUND: End stage renal disease (ESRD) is associated with platelet dysfunction but also thromboembolic complications. The specific role of increased blood urea nitrogen (BUN) on coagulation is unclear. We aimed to characterize thromboelastography (TEG) parameters from males and females with ESRD and normal kidney function and evaluate if exogenous urea in vitro reproduced those TEG differences. METHODS: We collected blood samples from 20 living kidney donors and 20 kidney recipients. TEG was performed without and with two increasing urea concentrations in vitro. TEG parameters were compared between recipients and donors. RESULTS: Blood from kidney recipients showed baseline increased maximum amplitude (MA) and shortened time to maximum amplitude (TMA) compared to donors. These differences were not confirmed in females. In all patients, BUN was inversely correlated with TMA (r = -0.342; p = 0.031). In males, BUN and creatinine concentrations showed a direct correlation with MA (0.583; p = 0.007) and an inverse correlation with TMA (r = -0.520; p = 0.019). Urea in vitro decreased R-time (p = 0.005) and increased LY30 (p = 0.009) in donors but not recipients. CONCLUSIONS: ESRD is associated with increased MA and decreased TMA on TEG. No change in MA was observed with increasing urea concentrations in vitro. Gender-specific variability in TEG parameters were observed.

Best Practice Alerts Informed by Inpatient Opioid Intake to Reduce Opioid Prescribing after Surgery (PRIOR): A Cluster Randomized Multiple Crossover Trial.

BACKGROUND: Overprescription of opioids after surgery remains common. Residual and unnecessarily prescribed opioids can provide a reservoir for nonmedical use. This study therefore tested the hypothesis that a decision-support tool embedded in electronic health records guides clinicians to prescribe fewer opioids at discharge after inpatient surgery. METHODS: This study included 21,689 surgical inpatient discharges in a cluster randomized multiple crossover trial from July 2020 to June 2021 in four Colorado hospitals. Hospital-level clusters were randomized to alternating 8-week periods during which an electronic decision-support tool recommended tailored discharge opioid prescriptions based on previous inpatient opioid intake. During active alert periods, the alert was displayed to clinicians when the proposed opioid prescription exceeded recommended amounts. No alerts were displayed during inactive periods. Carryover effects were mitigated by including 4-week washout periods. The primary outcome was oral morphine milligram equivalents prescribed at discharge. Secondary outcomes included combination opioid and nonopioid prescriptions and additional opioid prescriptions until day 28 after discharge. A vigorous state-wide opioid education and awareness campaign was in place during the trial. RESULTS: The total postdischarge opioid prescription was a median [quartile 1, quartile 3] of 75 [0, 225] oral morphine milligram equivalents among 11,003 patients discharged when the alerts were active and 100 [0, 225] morphine milligram equivalents in 10,686 patients when the alerts were inactive, with an estimated ratio of geometric means of 0.95 (95% CI, 0.80 to 1.13; P = 0.586). The alert was displayed in 28% (3,074 of 11,003) of the discharges during the active alert period. There was no relationship between the alert and prescribed opioid and nonopioid combination medications or additional opioid prescriptions written after discharge. CONCLUSIONS: A decision-support tool incorporated into electronic medical records did not reduce discharge opioid prescribing for postoperative patients in the context of vigorous opioid education and awareness efforts. Opioid prescribing alerts might yet be valuable in other contexts.(Anesthesiology 2023; 139:186-96).

Accelerometer-Measured Inpatient Physical Activity and Associated Outcomes After Major Abdominal Surgery: Systematic Review.

BACKGROUND: It remains unclear how inpatient physical activity after major abdominal surgery affects outcomes. Accelerometer research may provide further evidence for postoperative mobilization. OBJECTIVE: We aimed to summarize the current literature evaluating the impact of accelerometer-measured postoperative physical activity on outcomes after major abdominal surgery. METHODS: We searched PubMed and Google Scholar in October 2021 to conduct a systematic review. Studies were included if they used accelerometers to measure inpatient physical behaviors immediately after major abdominal surgery, defined as any nonobstetric procedures performed under general anesthesia requiring hospital admission. Studies were eligible only if they evaluated the effects of physical activity on postoperative outcomes such as postoperative complications, return of gastrointestinal function, hospital length of stay, discharge destination, and readmissions. We excluded studies involving participants aged <18 years. Risk of bias was assessed using the risk-of-bias assessment tool for nonrandomized studies (RoBANS) for observational studies and the revised Cochrane risk-of-bias tool for randomized trials (RoB 2) for randomized controlled trials (RCTs). Findings were summarized by qualitative synthesis. RESULTS: We identified 15 studies. Risk of bias was high in 14 (93%) of the 15 studies. Most of the studies (11/15, 73%) had sample sizes of <100. Of the 15 studies, 13 (87%) included the general surgery population, 1 (7%) was a study of patients who had undergone gynecologic surgery, and 1 (7%) included a mixed (abdominal, thoracic, gynecologic, and orthopedic) surgical population. Of the 15 studies, 12 (80%) used consumer-grade accelerometers to measure physical behaviors. Step count was the most commonly reported physical activity outcome (12/15, 80%). In the observational studies (9/15, 60%), increased physical activity during the immediate postoperative period was associated with earlier return of gastrointestinal function, fewer surgical and pulmonary complications, shorter hospital length of stay, and fewer readmissions. In the RCTs (6/15, 40%), only 1 (17%) of the 6 studies demonstrated improved outcomes (shorter time to flatus and hospital length of stay) when a mobility-enhancing intervention was compared with usual care. Notably, mobility-enhancing interventions used in 4 (67%) of the 6 RCTs did not result in increased postoperative physical activity. CONCLUSIONS: Although observational studies show strong associations between postoperative physical activity and outcomes after major abdominal surgery, RCTs have not proved the benefit of mobility-enhancing interventions compared with usual care. The overall risk of bias was high, and we could not synthesize specific recommendations for postoperative mobilization. Future research would benefit from improving study design, increasing methodologic rigor, and measuring physical behaviors beyond step counts to understand the impact of postoperative mobilization on outcomes after major abdominal surgery.

An anesthesia-centered bundle to reduce postoperative pulmonary complications: The PRIME-AIR study protocol.

BACKGROUND: Postoperative pulmonary complications (PPCs) are a major cause of morbidity and mortality after open abdominal surgery. Optimized perioperative lung expansion may minimize the synergistic factors responsible for the multiple-hit perioperative pulmonary dysfunction. This ongoing study will assess whether an anesthesia-centered bundle focused on perioperative lung expansion results in decreased incidence and severity of PPCs after open abdominal surgery. METHODS: Prospective multicenter randomized controlled pragmatic trial in 750 adult patients with at least moderate risk for PPCs undergoing prolonged (≥2 hour) open abdominal surgery. Participants are randomized to receive either a bundle intervention focused on perioperative lung expansion or usual care. The bundle intervention includes preoperative patient education, intraoperative protective ventilation with individualized positive end-expiratory pressure to maximize respiratory system compliance, optimized neuromuscular blockade and reversal management, and postoperative incentive spirometry and early mobilization. Primary outcome is the distribution of the highest PPC severity by postoperative day 7. Secondary outcomes include the proportion of participants with: PPC grades 1-2 through POD 7; PPC grades 3-4 through POD 7, 30 and 90; intraoperative hypoxemia, rescue recruitment maneuvers, or cardiovascular events; and any major extrapulmonary postoperative complications. Additional secondary and exploratory outcomes include individual PPCs by POD 7, length of postoperative oxygen therapy or other respiratory support, hospital resource use parameters, Patient-Reported Outcomes Measurements (PROMIS®) questionnaires for dyspnea and fatigue collected before and at days 7, 30 and 90 after surgery, and plasma concentrations of lung injury biomarkers (IL6, IL-8, RAGE, CC16, Ang-2) analyzed from samples obtained before, end of, and 24 hours after surgery. DISCUSSION: Participant recruitment for this study started January 2020; results are expected in 2024. At the conclusion of this trial, we will determine if this anesthesia-centered strategy focused on perioperative lung expansion reduces lung morbidity and healthcare utilization after open abdominal surgery. TRIAL REGISTRATION: ClinicalTrial.gov NCT04108130.

Hyperoxemia During Cardiac Surgery Is Associated With Postoperative Pulmonary Complications.

The use of hyperoxemia during cardiac surgery remains controversial. We hypothesized that intraoperative hyperoxemia during cardiac surgery is associated with an increased risk of postoperative pulmonary complications. DESIGN: Retrospective cohort study. SETTING: We analyzed intraoperative data from five hospitals within the Multicenter Perioperative Outcomes Group between January 1, 2014, and December 31, 2019. We assessed intraoperative oxygenation of adult patients undergoing cardiac surgery with cardiopulmonary bypass (CPB). Hyperoxemia pre and post CPB was quantified as the area under the curve (AUC) of Fio2 above 0.21 in minutes when the corresponding peripheral oxygen saturation was greater than 92% measured by pulse oximetry. We quantified hyperoxemia during CPB as the AUC of Pao2 greater than 200 mm Hg measured by arterial blood gas. We analyzed the association of hyperoxemia during all phases of cardiac surgery with the frequency of postoperative pulmonary complications within 30 days, including acute respiratory insufficiency or failure, acute respiratory distress syndrome, need for reintubation, and pneumonia. PATIENTS: Twenty-one thousand six hundred thirty-two cardiac surgical patients. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: During 21,632 distinct cardiac surgery cases, 96.4% of patients spent at least 1 minute in hyperoxemia (99.1% pre-CPB, 98.5% intra-CPB, and 96.4% post-CPB). Increasing exposure to hyperoxemia was associated with an increased risk of postoperative pulmonary complications throughout three distinct surgical periods. During CPB, increasing exposure to hyperoxemia was associated with an increased odds of developing postoperative pulmonary complications (p < 0.001) in a linear manner. Hyperoxemia before CPB (p < 0.001) and after CPB (p = 0.02) were associated with increased odds of developing postoperative pulmonary complications in a U-shaped relationship. CONCLUSIONS: Hyperoxemia occurs almost universally during cardiac surgery. Exposure to hyperoxemia assessed continuously as an AUC during the intraoperative period, but particularly during CPB, was associated with an increased incidence of postoperative pulmonary complications.

Lidocaine Intraoperative Infusion Pharmacokinetics during Partial Hepatectomy for Living Liver Donation.

BACKGROUND: Postoperative pain associated with open partial hepatectomy can be intense and persistent. The multimodal approach used to lessen this problem includes an intraoperative intravenous infusion of lidocaine hydrochloride. Decreased hepatic metabolism after resection raises concerns about safe lidocaine dosing in this patient population. The hypothesis was that the elimination clearance of lidocaine and its metabolites, monoethylglycinexylidide and glycinexylidide, is reduced after a partial hepatectomy, as reflected by observed plasma concentrations that are higher and have a longer half-life than expected based on pharmacokinetic modeling (estimated for normal liver function). Secondarily, this study postulated that plasma concentrations of lidocaine, monoethylglycinexylidide, and glycinexylidide do not reach toxic concentrations with institutional protocol up to 24 h after surgery. METHODS: Blood samples were collected from 15 patients undergoing a partial hepatectomy for living liver donation, at the following specific time points: before and immediately after induction of anesthesia, during hepatectomy, 30 min after hepatectomy completion, at case end, and 24 h after the end of surgery. Plasma concentrations of lidocaine and metabolites were measured by liquid chromatography-mass spectrometry. The population lidocaine pharmacokinetics were estimated, and total body weight and the fraction of remaining liver mass as potential model covariates were evaluated. The detection of any lidocaine, monoethylglycinexylidide, or glycinexylidide toxic plasma concentrations at any time point during and after hepatectomy were also evaluated. RESULTS: The typical value for lidocaine elimination clearance was 0.55 ± 0.12 l/min (± standard error of the estimate) which, on average, was reduced to about one third of the baseline clearance, 0.17 ± 0.02 l/min, once the donor graft was surgically isolated, and remained so for 24 h according to the current data and model. The fraction of remaining liver was a significant covariate for the posthepatectomy lidocaine clearance' such that if 50% of the liver is removed the clearance is reduced by approximately 60%. Plasma concentrations of lidocaine and its metabolites remained below their theoretical combined toxic threshold concentrations throughout the surgical and postoperative course in all patients, with one exception obtained near induction of anesthesia. Plasma lidocaine concentrations decreased at case end and postoperatively, while metabolite concentrations continued to rise at the end of surgery with reduction postoperatively. Pharmacokinetic modeling revealed that the only significant covariate in the model was the fraction of liver remaining after isolation of the donor graft. CONCLUSIONS: Intravenous lidocaine infusions are an acceptable option for multimodal pain management in patients undergoing a hepatectomy for living donation if the lidocaine infusion is stopped when the liver resection is complete. Clearance of lidocaine is decreased proportionally to the remaining liver mass, which should guide lidocaine infusion administration or dosing adjustments for patients undergoing liver resection surgery.

Incidence of Postoperative Cognitive Dysfunction Following Inhalational vs Total Intravenous General Anesthesia: A Systematic Review and Meta-Analysis.

Postoperative cognitive dysfunction (POCD) has been increasingly recognized as a contributor to postoperative complications. A consensus-working group recommended that POCD should be distinguished between delayed cognitive recovery, ie, evaluations up to 30 days postoperative, and neurocognitive disorder, ie, assessments performed between 30 days and 12 months after surgery. Additionally, the choice of the anesthetic, either inhalational or total intravenous anesthesia (TIVA) and its effect on the incidence of POCD, has become a focus of research. Our primary objective was to search the literature and conduct a meta-analysis to verify whether the choice of general anesthesia may impact the incidence of POCD in the first 30 days postoperatively. As a secondary objective, a systematic review of the literature was conducted to estimate the effects of the anesthetic on POCD between 30 days and 12 months postoperative. For the primary objective, an initial review of 1913 articles yielded ten studies with a total of 3390 individuals. For the secondary objective, four studies with a total of 480 patients were selected. In the first 30 days postoperative, the odds-ratio for POCD in TIVA group was 0.46 (95% CI = 0.26-0.81; p = 0.01), compared to the inhalational group. TIVA was associated with a lower incidence of POCD in the first 30 days postoperatively. Regarding the secondary objective, due to the small number of selected articles and its high heterogeneity, a metanalysis was not conducted. Given the heterogeneity of criteria for POCD, future prospective studies with more robust designs should be performed to fully address this question.

Postoperative pulmonary complications with adjuvant regional anesthesia versus general anesthesia alone: a sub-analysis of the Perioperative Research Network study.

BACKGROUND: Adjuvant regional anesthesia is often selected for patients or procedures with high risk of pulmonary complications after general anesthesia. The benefit of adjuvant regional anesthesia to reduce postoperative pulmonary complications remains uncertain. In a prospective observational multicenter study, patients scheduled for non-cardiothoracic surgery with at least one postoperative pulmonary complication surprisingly received adjuvant regional anesthesia more frequently than those with no complications. We hypothesized that, after adjusting for surgical and patient complexity variables, the incidence of postoperative pulmonary complications would not be associated with adjuvant regional anesthesia. METHODS: We performed a secondary analysis of a prospective observational multicenter study including 1202 American Society of Anesthesiologists physical status 3 patients undergoing non-cardiothoracic surgery. Patients were classified as receiving either adjuvant regional anesthesia or general anesthesia alone. Predefined pulmonary complications within the first seven postoperative days were prospectively identified. Groups were compared using bivariable and multivariable hierarchical logistic regression analyses for the outcome of at least one postoperative pulmonary complication. RESULTS: Adjuvant regional anesthesia was performed in 266 (22.1%) patients and not performed in 936 (77.9%). The incidence of postoperative pulmonary complications was greater in patients receiving adjuvant regional anesthesia (42.1%) than in patients without it (30.9%) (site adjusted p = 0.007), but this association was not confirmed after adjusting for covariates (adjusted OR 1.37; 95% CI, 0.83-2.25; p = 0.165). CONCLUSION: After adjusting for surgical and patient complexity, adjuvant regional anesthesia versus general anesthesia alone was not associated with a greater incidence of postoperative pulmonary complications in this multicenter cohort of non-cardiothoracic surgery patients.

Perioperative Pulmonary Atelectasis: Part II. Clinical Implications.

The development of pulmonary atelectasis is common in the surgical patient. Pulmonary atelectasis can cause various degrees of gas exchange and respiratory mechanics impairment during and after surgery. In its most serious presentations, lung collapse could contribute to postoperative respiratory insufficiency, pneumonia, and worse overall clinical outcomes. A specific risk assessment is critical to allow clinicians to optimally choose the anesthetic technique, prepare appropriate monitoring, adapt the perioperative plan, and ensure the patient's safety. Bedside diagnosis and management have benefited from recent imaging advancements such as lung ultrasound and electrical impedance tomography, and monitoring such as esophageal manometry. Therapeutic management includes a broad range of interventions aimed at promoting lung recruitment. During general anesthesia, these strategies have consistently demonstrated their effectiveness in improving intraoperative oxygenation and respiratory compliance. Yet these same intraoperative strategies may fail to affect additional postoperative pulmonary outcomes. Specific attention to the postoperative period may be key for such outcome impact of lung expansion. Interventions such as noninvasive positive pressure ventilatory support may be beneficial in specific patients at high risk for pulmonary atelectasis (e.g., obese) or those with clinical presentations consistent with lung collapse (e.g., postoperative hypoxemia after abdominal and cardiothoracic surgeries). Preoperative interventions may open new opportunities to minimize perioperative lung collapse and prevent pulmonary complications. Knowledge of pathophysiologic mechanisms of atelectasis and their consequences in the healthy and diseased lung should provide the basis for current practice and help to stratify and match the intensity of selected interventions to clinical conditions.

Association Between Anesthesia Delivered During Tumor Resection and Cancer Survival: a Systematic Review of a Mixed Picture with Constant Themes.

BACKGROUND: Surgery is required for cure of most solid tumors, and general anesthesia is required for most cancer surgery. The vast majority of cancer surgery is facilitated by general anesthesia using volatile inhalational agents such as isoflurane and sevoflurane. Only recently have the immunologic and oncologic effect of inhalational agents, and their alternative, propofol-based total intravenous anesthesia (TIVA), come under investigation. METHODS: Between January 2019 and June 2020, English language articles on PubMed were searched for the keywords "Propofol" "TIVA" or "IV anesthesia" and either "cancer surgery" or "surgical oncology." Duplicates were removes, manuscripts classified as either in vitro, animal, translational, or clinical studies, and their results summarized within these categories. RESULTS: In-vitro and translational data suggest that inhalational anesthetics are potent immunosuppressive and tumorigenic agents that promote metastasis, while propofol is anti-inflammatory, anti-tumorigenic, and prevents metastasis development. Clinically there is a recurring association, based largely on retrospective, single institution series, that TIVA is associated with significant improvements in disease-free interval and overall survival in a number of, but not all, solid tumors. The longer the surgery is, the more intense the surgical trauma is, the more aggressive the malignancy is, and the higher likelihood of an association is. DISCUSSION: Prospective randomized trials, coupled with basic science and translational studies, are needed to further define this association.

Characteristics and Outcomes of Mechanically Ventilated COVID-19 Patients-An Observational Cohort Study.

BACKGROUND: The United States currently has more confirmed cases of COVID-19 than any other country in the world. Given the variability in COVID-19 testing and prevention capability, identifying factors associated with mortality in patients requiring mechanical ventilation is critical. This study aimed to identify which demographics, comorbidities, markers of disease progression, and interventions are associated with 30-day mortality in COVID-19 patients requiring mechanical ventilation. METHODS: Adult patients with a confirmed diagnosis of COVID-19 admitted to one of the health system's intensive care units and requiring mechanical ventilation between March 9, 2020 and April 1, 2020, were included in this observational cohort study. We used Chi-Square and Mann-Whitney U tests to compare patient characteristics between deceased and living patients and multiple logistic regression to assess the association between independent variables and the likelihood of 30-day mortality. RESULTS: We included 85 patients, of which 20 died (23.5%) within 30 days of the first hospital admission. In the univariate analysis, deceased patients were more likely ≥60 years of age (p < 0.001), non-Hispanic (p = 0.026), and diagnosed with a solid malignant tumor (p = 0.003). Insurance status also differed between survivors and non-survivors (p = 0.019). Age ≥60 and malignancy had a 9.5-fold (95% confidence interval 1.4-62.3, p = 0.020) and 5.8-fold higher odds ratio (95% confidence interval 1.2-28.4, p = 0.032) for 30-day mortality after adjusted analysis using multivariable logistic regression, while other independent variables were no longer significant. CONCLUSIONS: In our observational cohort study of 85 mechanically ventilated COVID-19 patients, age, and a diagnosis of a solid malignant tumor were associated with 30-day mortality. Our findings validate concerns for the survival of elderly and cancer patients in the face of the COVID-19 pandemic in the United States, where testing capabilities and preventative measures have been inconsistent. Preventative efforts geared to patients at risk for intensive care unit mortality from COVID-19 should be explored.

Association between procalcitonin levels and duration of mechanical ventilation in COVID-19 patients.

BACKGROUND: Patients diagnosed with COVID-19 frequently require mechanical ventilation. Knowledge of laboratory tests associated with the prolonged need for mechanical ventilation may guide resource allocation. We hypothesized that an elevated plasma procalcitonin level (>0.1 ng/ml) would be associated with the duration of invasive mechanical ventilation. METHODS: Patients diagnosed with COVID-19, who were admitted to any of our health system's hospitals between March 9th-April 20th, 2020 and required invasive mechanical ventilation, were eligible for this observational cohort study. Demographics, comorbidities, components of the Sequential Organ Failure Assessment score, and procalcitonin levels on admission were obtained from the electronic health record. The primary outcome was the duration of mechanical ventilation; secondary outcomes included 28-day mortality and time to intubation. Outcomes were assessed within the first 28 days of admission. Baseline demographics and comorbidities were summarized by descriptive statistics. Univariate comparisons were made using Pearson's chi-square test for binary outcomes and Mann-Whitney U test for continuous outcomes. A multiple linear regression was fitted to assess the association between procalcitonin levels and the duration of mechanical ventilation. RESULTS: Patients with an initial procalcitonin level >0.1 ng/ml required a significantly longer duration of mechanical ventilation than patients with a level of ≤0.1 ng/ml (p = 0.021) in the univariate analysis. There was no significant difference in 28-day mortality or time to intubation between the two groups. After adjusted analysis using multivariable linear regression, the duration of mechanical ventilation was, on average, 5.6 (p = 0.016) days longer in patients with an initial procalcitonin level >0.1 ng/ml. CONCLUSION: In this cohort of 93 mechanically ventilated COVID-19 patients, we found an association between an initial plasma procalcitonin level >0.1 ng/ml and the duration of mechanical ventilation. These findings may help to identify patients at risk for prolonged mechanical ventilation upon admission.

Opioid-Free Epidural-Free Anesthesia for Open Hepatectomy: A Case Report.

Opioid-free perioperative approaches hold promise to reduce opioid use after surgery and their associated side effects. Here, we report the perioperative analgesic plan of a patient who requested opioid-free care for an open partial hepatectomy. Opioid-free anesthesia care for abdominal surgery is usually dependent on epidural analgesia. However, as in this case, placing an epidural is not always an option due to contraindications such as infection, coagulopathy, or patient refusal. Our multimodal management plan provided an alternative opioid-free, epidural-free perioperative strategy that may prove useful for other patients undergoing similar surgeries.

Individualized PEEP to optimise respiratory mechanics during abdominal surgery: a pilot randomised controlled trial.

BACKGROUND: Higher intraoperative driving pressures (ΔP) are associated with increased postoperative pulmonary complications (PPC). We hypothesised that dynamic adjustment of PEEP throughout abdominal surgery reduces ΔP, maintains positive end-expiratory transpulmonary pressures (Ptp_ee) and increases respiratory system static compliance (Crs) with PEEP levels that are variable between and within patients. METHODS: In a prospective multicentre pilot study, adults at moderate/high risk for PPC undergoing elective abdominal surgery were randomised to one of three ventilation protocols: (1) PEEP≤2 cm H2O, compared with periodic recruitment manoeuvres followed by individualised PEEP to either optimise respiratory system compliance (PEEPmaxCrs) or maintain positive end-expiratory transpulmonary pressure (PEEPPtp_ee). The composite primary outcome included intraoperative ΔP, Ptp_ee, Crs, and PEEP values (median (interquartile range) and coefficients of variation [CVPEEP]). RESULTS: Thirty-seven patients (48.6% female; age range: 47-73 yr) were assigned to control (PEEP≤2 cm H2O; n=13), PEEPmaxCrs (n=16), or PEEPPtp_ee (n=8) groups. The PEEPPtp_ee intervention could not be delivered in two patients. Subjects assigned to PEEPmaxCrs had lower ΔP (median8 cm H2O [7-10]), compared with the control group (12 cm H2O [10-15]; P=0.006). PEEPmaxCrs was also associated with higher Ptp_ee (2.0 cm H2O [-0.7 to 4.5] vs controls: -8.3 cm H2O [-13.0 to -4.0]; P≤0.001) and higher Crs (47.7 ml cm H2O [43.2-68.8] vs controls: 39.0 ml cm H2O [32.9-43.4]; P=0.009). Individualised PEEP (PEEPmaxCrs and PEEPPtp_ee combined) varied widely (median: 10 cm H2O [8-15]; CVPEEP=0.24 [0.14-0.35]), both between, and within, subjects throughout surgery. CONCLUSIONS: This pilot study suggests that individualised PEEP management strategies applied during abdominal surgery reduce driving pressure, maintain positive Ptp_ee and increase static compliance. The wide range of PEEP observed suggests that an individualised approach is required to optimise respiratory mechanics during abdominal surgery. CLINICAL TRIAL REGISTRATION: NCT02671721.

Postdischarge Pain Management After Thoracic Surgery: A Patient-Centered Approach.

BACKGROUND: Postoperative analgesia is paramount to recovery after thoracic surgery, and opioids play an invaluable role in this process. However, current 1-size-fits-all prescribing practices produce large quantities of unused opioids, thereby increasing the risk of nonmedical use and overdose. This study hypothesized that patient and perioperative characteristics, including 24-hour before-discharge opioid intake, could inform more appropriate postdischarge prescriptions after thoracic surgery. METHODS: This prospective observational cohort study was conducted in 200 adult thoracic surgical patients. The cohort was divided into 3 groups on the basis of 24-hour before-discharge opioid intake in morphine milligram equivalents (MME): (1) no (0 MME), (2) low (>0 to ≤22.5 MME), or (3) high (>22.5 MME) before-discharge opioid intake. Logistic regression was used to analyze the association of patient and perioperative characteristics with self-reported after-discharge opioid use. RESULTS: Univariate analysis showed that preoperative opioid use, 24-hour before-discharge acetaminophen and gabapentinoid intake, and 24-hour before-discharge opioid intake were associated with higher after-discharge opioid use. Multivariable modeling demonstrated that 24-hour before-discharge opioid intake was most significantly associated with after-discharge opioid use. For example, compared with patients who took high amounts of opioids before discharge, patients who took no opioids before discharge were 99% less likely to take a high amount of opioids after discharge compared with taking none (odds ratio, 0.011; 95% confidence interval, 0.003 to 0.047; P < .001). CONCLUSIONS: Assessment of 24-hour before-discharge opioid intake may inform patient requirements after discharge. Opioid prescriptions after thoracic surgery can thereby be targeted on the basis of anticipated needs.

Hypoxemia Within the First 3 Postoperative Days Is Associated With Increased 1-Year Postoperative Mortality After Adjusting for Perioperative Opioids and Other Confounders.

BACKGROUND: Postoperative hypoxemia (POH) is common and primarily treated with temporary oxygen supplementation. Because the clinical impact of POH is sometimes presumed as minor, efforts to better understand and minimize it have been limited. Here, we hypothesized that, after adjusting for opioids received perioperatively and other confounders, the frequency of POH events (POH%) reported within the first 3 postoperative days (PODs) is associated with increased postoperative 1-year mortality. METHODS: With prior institutional review board (IRB) approval, the Epic Clarity database was queried for all adult inpatient anesthesia encounters performed at our health system (1 academic and 2 community hospitals) from January 1, 2012 to March 31, 2016. Patients with multiple hospitalizations or subsequent surgeries within the same hospitalization were excluded. We classified patients based on the presence (POH) or not (No-POH) of ≥1 documented peripheral saturation of oxyhemoglobin (SpO2) ≤85% event of any duration occurring between the discharge from the postanesthesia care unit (PACU) until POD 3. Demographics, comorbidities, surgery duration, morphine milligram equivalents (OMME) administered perioperatively, respiratory therapies, intensive care unit (ICU) admission, and hospital length of stay (LOS) were also collected. Logistic regression was used to characterize the association between POH and 1-year postoperative mortality after adjusting for perioperatively administered opioids and other confounding factors. RESULTS: A total of 43,011 patients met study criteria. At least 1 POH event was reported in 10,727 (24.9%) patients. Of these, 7179 (66.9%) had ≥1 hypoxemic event on POD 1, 5340 (49.8%) on POD 2, and 3455 (32.3%) on POD 3. Patients with ≥1 POH event, compared to No-POH patients, were older, had more respiratory and other comorbidities, underwent longer surgeries, received greater opioid doses on the day of surgery and POD 1, and received more continuous pulse oximetry monitoring. POH patients required more frequent postoperative oxygen therapy, noninvasive ventilation (NIV), intubation, and ICU admission. One-year postoperative mortality occurred in 4.4% of patients with ≥1 POH and 3.0% of No-POH patients (P < .001). After adjusting for confounding factors, for every 10% increase in the frequency of SpO2 ≤85% readings, the odds of postoperative 1-year mortality were 1.20 (95% confidence interval [CI], 1.11-1.29; P < .001). Perioperative opioids were not independently associated with increased 1-year mortality. CONCLUSIONS: After adjusting for perioperative opioids and other confounders, moderate/severe POH within the first 3 PODs was independently associated with increased 1-year postoperative mortality. Increased efforts should be directed to understand if efforts to detect and reduce POH lead to improved patient outcomes.