Effects of low-dose intraoperative fentanyl on postoperative respiratory complication rate: a pre-specified, retrospective analysis

Intraoperative Opioid Waste and Association of Intraoperative Opioid Dose with Postoperative Adverse Outcomes: A Hospital Registry Study

INTRODUCTION

Perioperative opioid use has been associated with adverse clinical outcomes. Additionally, opioid disposal carries significant costs, due to the waste of pharmaceutical products and the time needed by skilled labor to report the waste. In this study, we aimed to estimate costs and predict factors of opioid-associated intraoperative product waste, as well as to evaluate whether higher intraoperative opioid doses are associated with increased risk of adverse postoperative outcomes.

METHODS

We included 170,607 patients undergoing general anesthesia and receiving intraoperative fentanyl, hydromorphone, or morphine at Beth Israel Deaconess Medical Center, Boston, MA, USA, between January 2010 and June 2020. We estimated product waste-associated costs based on various opioid syringe sizes and determined predictors of opioid waste. Further, we evaluated whether higher opioid doses were associated with postoperative adverse events according to the severity-indexed, incident report-based medication error-reporting program classification. The primary outcome included post-extubation desaturation, postoperative nausea or vomiting, or postoperative somnolence or sedation.

RESULTS

The use of the smallest syringe sizes (50 mcg for fentanyl, 0.2 mg for hydromorphone, and 2 mg for morphine) resulted in the lowest product waste-associated costs. The main predictor of opioid waste was the administration of more than one intraoperative opioid (adjusted odds ratio [aOR] = 7.64, 95% CI 7.40-7.89, P < 0.001). Intraoperative doses of fentanyl > 50-100 mcg (aOR = 1.17 [1.10-1.25], P < 0.001, adjusted risk difference [ARD] 2%) and > 100 mcg (aOR = 1.24 [1.16-1.33], P < 0.001, ARD 3%), hydromorphone > 1 mg (aOR = 1.13 [1.06-1.20], P < 0.001, ARD 2%), and morphine > 2-4 mg (aOR = 1.26 [1.02-1.56], P = 0.04, ARD 3%) and > 4 mg (aOR = 1.45 [1.18-1.77], P < 0.001, ARD 5%) were associated with higher risk of the primary outcome.

CONCLUSION

Smaller syringe sizes of intraoperative opioids may help to reduce product waste and associated costs, as well postoperative adverse events through utilization of lower intraoperative opioid doses.

Effect of ultrasound-guided transversus abdominis plane block in reducing atelectasis after laparoscopic surgery in children: A randomized clinical trial

Background

Atelectasis is a commonly observed postoperative complication of general anesthesia in children. Pulmonary protective ventilation strategies have been reported to have a beneficial effect on postoperative atelectasis in children. Therefore, the present study aimed to evaluate the efficacy of the ultrasound-guided transversus abdominis plane (TAP) block technique in preventing the incidence of postoperative atelectasis in children.

Materials and methods

This study enrolled 100 consecutive children undergoing elective laparoscopic bilateral hernia repair and randomly divided them into the control and TAP groups. Conventional lung-protective ventilation was initiated in both groups after the induction of general anesthesia. The children in the TAP group received an ultrasound-guided TAP block with 0.3 mL/kg of 0.5% ropivacaine after the induction of anesthesia.

Results

Anesthesia-induced atelectasis was observed in 24% and 84% of patients in the TAP (n = 50) and control (n = 50) groups, respectively, before discharge from the post-anesthetic care unit (T3; PACU) (odds ratio [OR], 0.062; 95% confidence interval [CI], 0.019-0.179; P < 0.001). No significant difference was observed between the control and TAP groups in terms of the lung ultrasonography (LUS) scores 5 min after endotracheal intubation (T1). However, the LUS scores were lower in the TAP group than those in the control group at the end of surgery (T2, P < 0.01) and before discharge from the PACU (T3, P < 0.001). Moreover, the ace, legs, activity, cry and consolability (FLACC) pain scores in the TAP group were lower than those in the control group at each postoperative time point.

Conclusion

Ultrasound-guided TAP block effectively reduced the incidence of postoperative atelectasis and alleviated pain in children undergoing laparoscopic surgery.

Correlation of pain perception and fentanyl consumption after major abdominal surgery with CGRP 4218T/C polymorphism: A prospective interventional study

Background and Aims

Genetic polymorphisms contribute to patients' variability in pain perception and response to opioid treatment. The present study evaluated the association of calcitonin gene-related peptide (CGRP) 4218T/C polymorphisms with fentanyl consumption over 24 h postoperatively in patients after major abdominal surgery.

Methods

Eighty-five patients undergoing major abdominal surgery under general anaesthesia were recruited. For postoperative analgesia, epidural fentanyl and intravenous paracetamol were provided. The CGRP 4218T/C genotype was analysed, and the association between the genotype of the patient and the total consumption of fentanyl in the first 24 h after surgery was assessed. The association between different genotypes, the severity of postoperative pain and the side effects of opioids were also studied.

Results

Our study population distribution included 52.9% of the T/T genotype (wild homozygote), 35.3% of the T/C genotype (heterozygote) and 11.8% of the C/C genotype (mutant homozygote). Mean (standard deviation) total fentanyl consumption in the first 24 h was found to be highest in the C/C group (212.0 [7.5] μg), followed by the T/T group (182.8 [9.9] μg) and was the least in the T/C group (159.6 [7.5] μg). The C/C group reported higher pain scores in all the study periods. There was no significant difference in the side effects of opioids, such as nausea, vomiting, sedation among different genotypes of CGRP 4218T/C.

Conclusion

The polymorphism of CGRP 4218T/C affects postoperative pain perception and analgesic consumption. Patients with the C/C genotype had higher postoperative fentanyl consumption and pain scores.

Balanced Nonopioid General Anesthesia With Lidocaine Is Associated With Lower Postoperative Complications Compared With Balanced Opioid General Anesthesia With Sufentanil for Cardiac Surgery With Cardiopulmonary Bypass: A Propensity Matched Cohort Study

BACKGROUND

There are no data on the effect of balanced nonopioid general anesthesia with lidocaine in cardiac surgery with cardiopulmonary bypass. The main study objective was to evaluate the association between nonopioid general balanced anesthesia and the postoperative complications in relation to opioid side effects.

METHODS

Patients undergoing cardiac surgery with cardiopulmonary bypass between 2019 and 2021 were identified. After exclusion of patients for heart transplantation, left ventricular assistance device, and off-pump surgery, we classified patients according to an opioid general balanced anesthesia or a nonopioid balanced anesthesia with lidocaine. The primary outcome was a collapsed composite of postoperative complications that comprise respiratory failure and confusion, whereas secondary outcomes were acute renal injury, pneumoniae, death, intensive care unit (ICU), and hospital length of stay.

RESULTS

We identified 859 patients exposed to opioid-balanced general anesthesia with lidocaine and 913 patients exposed to nonopioid-balanced general anesthesia. Propensity score matching yielded 772 individuals in each group with balanced baseline covariates. Two hundred thirty-six patients (30.5%) of the nonopioid-balanced general anesthesia versus 186 patients (24.1%) presented postoperative composite complications. The balanced lidocaine nonopioid general anesthesia group was associated with a lower proportion with the postoperative complication composite outcome OR, 0.72 (95% CI, 0.58-0.92; P = .027). The number of patients with acute renal injury, death, and hospital length of stay did not differ between the 2 groups.

CONCLUSIONS

A balanced nonopioid general anesthesia protocol with lidocaine was associated with lower odds of postoperative complication composite outcome based on respiratory failure and confusion.

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.

General anesthetic techniques for enhanced recovery after surgery: Current controversies

General anesthesia technique can influence not only immediate postoperative outcomes, but also long-term outcomes beyond hospital stay (e.g., readmission after discharge from hospital). There is lack of evidence regarding superiority of total intravenous anesthesia over inhalation anesthesia with regards to postoperative outcomes even in high-risk population including cancer patients. Optimal balanced general anesthetic technique for enhance recovery after elective surgery in adults includes avoidance of routine use preoperative midazolam, avoidance of deep anesthesia, use of opioid-sparing approach, and minimization of neuromuscular blocking agents and appropriate reversal of residual paralysis. Given that the residual effects of drugs used during anesthesia can increase postoperative morbidity and delay recovery, it is prudent to use a minimal number of drug combinations, and the drugs used are shorter-acting and administered at the lowest possible dose. It is imperative that the discerning anesthesiologist consider whether each drug used is really necessary for accomplishing perioperative goals.

Use of Serratus Anterior Plane and Transversus Thoracis Plane Blocks for Subcutaneous Implantable Cardioverter-Defibrillator (S-ICD) Implantation Decreases Intraoperative Opioid Requirements

OBJECTIVES

The present study investigated whether regional anesthetic techniques, especially truncal blocks, can provide adjunct anesthesia without the additional risk of general anesthesia and neuraxial techniques for subcutaneous implantable cardioverter-defibrillator (S-ICD) implantation.

DESIGN

Single-center, prospective, randomized study.

SETTING

Holding area and operating room at a single-center tertiary care hospital.

PARTICIPANTS

The study comprised 22 American Society of Anesthesiologists (ASA) physical status 3 or 4 patients with severe cardiac disease undergoing S-ICD implantation.

INTERVENTIONS

Patients received either a combination of serratus anterior plane block and transversus thoracis plane block or surgical infiltration of local anesthetics.

MEASUREMENTS AND MAIN RESULTS

Perioperative analgesic medication in the fascial plane block group versus the surgical wound infiltration group, visual analog pain scale score (0-10), intraoperative vital signs, total procedure time, and length of stay in the intensive care unit were measured. Total intraoperative fentanyl requirements (µg) were significantly less in the truncal block group versus the surgical infiltration group (45 [25-50] v 90 [50-100]; p = 0.026), and no patients had any adverse sequelae related to the study. Median intraoperative propofol use in the surgical infiltration group was 66.48 (47.30-73.73) µg/kg/min, and 65.95 (51.86-104.86) µg/kg/min for the truncal block group. This difference between the groups was not statistically significant (p = 0.293).

CONCLUSIONS

The performance of both the serratus anterior plane block and transversus thoracis plane blocks for S-ICD implantation are appropriate and may have the benefit of decreasing intraoperative opioid requirements.

Effect of peripheral nerve blocks on postanesthesia care unit length of stay in patients undergoing ambulatory surgery: a retrospective cohort study

BACKGROUND

Peripheral regional anesthesia and analgesia may increase the efficiency of ambulatory surgical centers by reducing pain and preventing nausea and vomiting, which are important modifiable causes of prolonged postanesthesia care unit (PACU) length of stay. We hypothesized that the use of peripheral nerve blocks (PNB) was associated with shorter PACU length of stay in ambulatory surgery.

METHODS

In this retrospective cohort study, we analyzed data from adult ambulatory surgical cases, in which PNB was a viable anesthetic option (ie, was routinely performed for these procedures), at an academic medical center between 2008 and 2018. We assessed the association between the use of PNB and the primary endpoint of PACU length of stay. As key secondary endpoint, we compared intraoperative opioid doses. Analyses were adjusted for patient demographics, comorbidities and intraoperative factors.

RESULTS

A total of 57 040 cases were analyzed, of whom 13 648 (23.9%) received a PNB. The use of PNB was associated with shorter PACU length of stay (a decrease of 7.3 min, 95% CI 6.1 to 8.6, p<0.001). This association was most pronounced in surgeries of long duration (decrease of 11.2 min, 95% CI 9.0 to 13.4) and in patients undergoing leg and ankle procedures (decrease of 15.1 min, 95% CI 5.5 to 24.6). Intraoperative opioid doses were significantly lower in patients receiving a nerve block (decrease of 9.40 mg oral morphine equivalents, 95% CI 8.34 to 10.46, p<0.001).

CONCLUSION

The use of PNB significantly reduced PACU length of stay in ambulatory surgical patients, which may in part be attributed to lower intraoperative opioid requirements.

Supraglottic airway device versus tracheal intubation and the risk of emergent postoperative intubation after general anaesthesia in adults: a retrospective cohort study

BACKGROUND

We examined the association between emergent postoperative tracheal intubation and the use of supraglottic airway devices (SGAs) vs tracheal tubes.

METHODS

We included data from adult noncardiac surgical cases under general anaesthesia between 2008 and 2018. We only included cases (n=59 991) in which both airways were deemed to be feasible options. Multivariable logistic regression, instrumental variable analysis, propensity matching, and mediation analysis were used.

RESULTS

Use of a tracheal tube was associated with a higher risk of emergent postoperative intubation (adjusted absolute risk difference [ARD]=0.80%; 95% confidence interval (CI), 0.64-0.97; P<0.001), and a higher risk of post-extubation hypoxaemia (ARD=3.9%; 95% CI, 3.4-4.4; P<0.001). The effect was modified by the use of non-depolarising neuromuscular blocking agents (NMBAs); mediation analyses revealed that 28.9% (95% CI, 14.4-43.4%; P<0.001) of the main effect was attributable to NMBA. Airway management modified the association of NMBA and risk of emergent postoperative intubation (P_interaction=0.02). Patients managed with an SGA had higher odds of NMBA-associated reintubation compared to patients managed with a tracheal tube (adjusted odds ratio [aOR]=3.65, 95% CI, 1.99-6.67 vs aOR=1.68, 95% CI, 1.29-2.18 [P<0.001], respectively).

CONCLUSIONS

In patients undergoing procedures under general anaesthesia that could be managed with either SGA or tracheal tube, use of an SGA was associated with lower risk of emergent postoperative intubation. The effect can partly be explained by use of NMBAs. Use of NMBAs in patients with an SGA appears to increase the risk of emergent postoperative intubation.

Enhanced recovery pathways for ambulatory surgery

PURPOSE OF REVIEW

Implementation of enhanced recovery pathways have allowed migration of complex surgical procedures from inpatient setting to the outpatient setting. These programs improve patient safety and patient-reported outcomes. The present article discusses the principles of enhanced recovery pathways in adults undergoing ambulatory surgery with an aim of improving patient safety and postoperative outcomes.

RECENT FINDINGS

Procedure and patient selection is one of the key elements that influences perioperative outcomes after ambulatory surgery. Other elements include optimization of comorbid conditions, patient and family education, minimal preoperative fasting and adequate hydration during the fasting period, use of fast-track anesthesia technique, lung-protective mechanical ventilation, maintenance of fluid balance, and multimodal pain, nausea, and vomiting prophylaxis.

SUMMARY

Implementation of enhanced recovery pathways requires a multidisciplinary approach in which the anesthesiologist should take a lead in collaborating with surgeons and perioperative nurses. Measuring compliance with enhanced recovery pathways through an audit program is essential to evaluate success and need for protocol modification. The metrics to assess the impact of enhanced recovery pathways include complication rates, patient reported outcomes, duration of postoperative stay in the surgical facility, unplanned hospital admission rate, and 7-day and 30-day readmission rates.

Is postoperative atelectasis following lumbar fusion more prevalent among patients with chronic opioid use?

OBJECTIVE

Chronic opioid use (COU) remains on the rise globally, acting as a marker for patient morbidity and a risk factor for adverse health outcomes. Opioid use is a risk factor for respiratory depression, which may lead to dysfunctional breathing, a known cause of atelectasis. The objective of this study was to determine whether COU is associated with increased rates of postoperative atelectasis among patients undergoing lumbar fusion.

MATERIALS & METHODS

Three State Inpatient Databases were used to identify patients who underwent an elective lumbar fusion through an anterior, posterior or circumferential approach in Florida, Kentucky and New York between 2013-2015. Patients with COU and those with postoperative atelectasis were identified using ICD diagnosis codes. Three operative groups were created and subsequently matched using propensity scores in order to provide comparable cohorts for analysis. Three-to-one propensity score matching was conducted using the variables of age, sex, race, number of chronic diagnoses and geographic state of admission. Multivariable logistic regressions were used to examine the relationship between COU and postoperative atelectasis.

RESULTS

A total of 3618 lumbar fusions were identified. Atelectasis was noted in 1.33 % of NCOU patients and 2.32 % of COU patients. On multivariable analysis, while controlling for the Elixhauser Mortality Index and patient insurance status, COU was significantly associated with atelectasis in posterior lumbar fusion (OR = 2.27; CI: 1.09-4.72; p = 0.028) and circumferential lumbar fusion (OR = 4.68; CI: 1.52-14.45; p = 0.007). The Elixhauser Mortality Index was also significantly associated with atelectasis in posterior lumbar fusion (OR = 1.08; CI: 1.04-1.11; p < 0.001) and circumferential lumbar fusion (OR = 1.09; CI: 1.03-1.16; p = 0.002).

CONCLUSION

Higher rates of postoperative atelectasis were found among patients with COU following posterior and circumferential lumbar fusions. The Elixhauser Mortality Index was also independently associated with atelectasis. Knowledge of these risks may allow for earlier identification and intervention in patients who are at risk.

Effects of laparoscopic vs open abdominal surgery on costs and hospital readmission rate and its effect modification by surgeons' case volume

BACKGROUND

Laparoscopy provides a minimally invasive alternative to open abdominal surgery. Current data describing its association with hospital readmission and costs in relation to surgeon laparoscopic case volume is limited to smaller databases and subsets of operations.

METHODS

This retrospective cohort study of 23,285 adult abdominal operations from 2007 to 2015 compares 30-day readmission rate and costs between laparoscopic and open abdominal operations and examines effect modification by surgeon laparoscopic case volume. Outcomes were all-cause hospital readmission within 30 days after discharge and index hospital admission cost.

RESULTS

All-cause hospital readmission rates were significantly lower after laparoscopic abdominal operations compared with open operations (adjusted odds ratio [aOR] 0.56, 95% CI 0.46-0.69, p < 0.001) with a difference in readmission risk attributable to laparoscopic approach of - 4.0% (95% CI - 5.4 to - 2.6%) in complete-case analysis. Among surgeons with a high laparoscopic case volume, the estimated difference in readmission risk through laparoscopy was magnified (- 5.8%, 95% CI - 7.5 to - 4.1%) compared to low surgeon laparoscopic case volume (- 2.9%, 95% CI - 4.8 to -1.1%, p for interaction = 0.005). The estimated difference in costs of the index hospital admission attributable to laparoscopic approach was - $3869 (95% CI - $4200 to - $3538; adjusted incidence rate ratio 0.77, 95% CI 0.75-0.79, p < 0.001). Laparoscopy was followed by significantly lower rates of readmissions related to gastrointestinal (aOR 0.68, 95% CI 0.55-0.85, p = 0.001), wound complications (infection: aOR 0.33, 95% CI 0.23-0.47, p < 0.001; non-infectious: aOR 0.47, 95% CI 0.30-0.74, p = 0.001), and malignancy (aOR 0.68, 95% CI 0.55-0.85, p < 0.001). The findings remain robust after multiple imputation and sensitivity analyses.

CONCLUSIONS

Laparoscopy versus open abdominal surgery is associated with reduced hospital readmissions related to malignancy, gastrointestinal, and wound complications. Effect modification by higher laparoscopy case volume argues for continued proliferation of laparoscopy in abdominal surgeries.

Outcomes of Transfemoral Transcatheter Aortic Valve Replacement Performed With General Anesthesia Using a Supraglottic Airway Versus Monitored Anesthesia Care

OBJECTIVE

Compare general anesthesia with a supraglottic airway versus monitored anesthesia care for transfemoral transcatheter aortic valve replacement (TF-TAVR) in patients with aortic stenosis. The authors hypothesized that the supraglottic airway group would have similar operating room and procedure times, postanesthesia care unit (PACU) and hospital stays, and similar rates of intraprocedural and postprocedural complications compared with the monitored anesthesia care group.

STUDY DESIGN

Retrospective chart review with 1:1 propensity score matching of supraglottic airway to monitored anesthesia care patients.

SETTING

Tertiary care academic medical center.

PARTICIPANTS

TF-TAVR patients between 2017 and 2019.

INTERVENTIONS

Supraglottic airway or monitored anesthesia care.

MEASUREMENTS AND MAIN RESULTS

One hundred forty-eight supraglottic airway patients were matched with 148 monitored anesthesia care patients. Monitored anesthesia care patients had slightly shorter operating room (p < 0.001) and procedure times (p = 0.015). No difference was observed in hospital length of stay (p = 0.34). Fewer patients in the supraglottic airway group required a PACU stay >2 hours (p < 0.001). Use of intraprocedural vasopressors (p < 0.001) and fentanyl dosage (p < 0.001) was higher in the supraglottic airway group. No differences were observed in postoperative complications or procedural success rates.

CONCLUSIONS

In this, the first study to compare these 2 modalities, supraglottic airway use was demonstrated to be a safe, feasible alternative to monitored anesthesia care during TF-TAVR and did not increase organ-specific morbidity, 30-day mortality, hospital length of stay, or PACU length of stay. Even though supraglottic airway was associated with slight increases in procedure and operating room times, these were not clinically significant.

Which Anesthesia Regimen Is Best to Reduce Pulmonary Complications After Head and Neck Surgery?

OBJECTIVES/HYPOTHESIS

The differences between intravenous and inhalation anesthesia in clinical postoperative pulmonary complications (PPCs) have been studied in cardiac and lung resection surgery. Clinical evidence for the effects of these two anesthetics on PPCs in other types of surgery is still missing. We aimed to assess the impact of sevoflurane and propofol on the incidence of PPCs in patients undergoing surgery for head and neck cancer.

STUDY DESIGN

Double-blind, randomized, controlled trial.

METHODS

We assigned 220 adults at intermediate-to-high risk of PPCs scheduled for head and neck cancer surgery with radial forearm or fibular flap reconstruction to either propofol or sevoflurane as a general anesthetic. The occurrence of pulmonary complications according to the Clavien-Dindo score was defined as the primary (within 7 days after surgery) outcome.

RESULTS

The PPC incidence during 7 days after surgery was 32.4% and 18.2% in the propofol and sevoflurane groups, respectively (P = .027). The corresponding incidence of PPCs in patients who underwent tracheotomy at the end of surgery in the two groups was 44.8% and 24.5%, respectively (P = .030). In addition, the Clavien-Dindo classification showed significant differences between groups in minor complications (grades I and II) but not in major complications (grades III-V).

CONCLUSIONS

Compared with intravenous anesthesia, the administration of sevoflurane reduces the incidence of minor PPCs (grades I and II) in moderate- and high-risk patients who have undergone tracheotomy after head and neck cancer surgery with radial forearm or fibular flap reconstruction.

LEVEL OF EVIDENCE

2 Laryngoscope, 131:E108-E115, 2021.

Calabadion 1 selectively reverses respiratory and central nervous system effects of fentanyl in a rat model

BACKGROUND

We hypothesised that Calabadion 1, an acyclic cucurbit[n]uril molecular container, reverses fentanyl-induced respiratory depression and dysfunction of the CNS.

METHODS

Experiments were conducted in male Sprague-Dawley rats. A constant-rate i.v. infusion of fentanyl (12.5 or 25 μg kg^-1 over 15 min) was administered followed by an i.v. bolus of Calabadion 1 (0.5-200 mg kg^-1) or placebo. The primary outcome was reversal of ventilatory and respiratory depression, assessed by pneumotachography and arterial blood gas analysis, respectively. Key secondary outcomes were effects on fentanyl-induced central nervous dysfunction quantified by righting reflex, balance beam test, and electromyography (EMG).

RESULTS

Calabadion 1 reversed fentanyl-induced respiratory depression across the endpoints minute ventilation, pH, and Paco₂ (P=0.001). Compared with placebo, Calabadion 1 dose dependently (P for trend <0.001) reversed fentanyl-induced hypoventilation {81.9 [5.1] (mean [standard error of the mean]) vs 45.5 [12.4] ml min^-1; P<0.001}, acidosis (pH 7.43 [0.01] vs 7.28 [0.04]; P=0.005), and hypercarbia (Paco₂ 43.4 [1.6] vs 63.4 [8.1] mm Hg; P=0.018). The effective Calabadion 1 doses required to reverse respiratory depression by 50% and 90% (ED50_Res and ED90_Res) were 1.7 and 15.6 mg kg^-1, respectively. Higher effective doses were needed for recovery of righting reflex (ED50_CNS: 9.6 mg kg^-1; ED90_CNS: 86.1 mg kg^-1), which was accelerated by Calabadion 1 (4.6 [0.3] vs 9.0 [0.7] min; P<0.001). Calabadion 1 also significantly accelerated recovery of full functional mobility and reversal of muscle rigidity.

CONCLUSIONS

Calabadion 1 selectively and dose dependently reversed the respiratory system and CNS side-effects of fentanyl.

Association between propofol dose and 1-year mortality in patients with or without a diagnosis of solid cancer

BACKGROUND

Preclinical data suggest suppression of cancer proliferation by propofol, and retrospective studies suggest improved survival after cancer surgery with propofol-based anaesthesia.

METHODS

To determine whether propofol dose administered for anaesthesia is associated with 1-yr mortality in patients with and without a diagnosis of solid cancer, we analysed adult patients undergoing monitored anaesthesia care or general anaesthesia at two academic medical centres in Boston, MA, USA. Logistic regression with interaction term analysis was applied with propofol dose (mg kg^-1) as primary and diagnosis of solid cancer as co-primary exposure, and 1-yr mortality as the primary outcome.

RESULTS

Of 280 081 patient cases, 10 744 (3.8%) died within 1 yr. Increasing propofol dose was associated with reduced odds of 1-yr mortality (adjusted odds ratio [aOR] 0.93 per 10 mg kg^-1; 95% confidence interval [CI]: 0.89-0.98; absolute risk reduction fifth vs first quintile 0.5%; 95% CI: 0.2-0.7). This association was modified by a diagnosis of solid cancer (P<0.001 for interaction). Increasing propofol dose was associated with reduced odds of 1-yr mortality in patients without solid cancer (aOR: 0.78; 95% CI: 0.71-0.85), but not in patients with solid cancer (0.99; 0.94-1.04), a finding that was replicated when examining 5-yr mortality.

CONCLUSIONS

Increasing propofol dose is associated with lower 1-yr mortality in patients without, but not in patients with, a diagnosis of solid cancer. We found evidence for competing effects, modifying the association between propofol dose and mortality.

The development and validation of the Score for the Prediction of Postoperative Respiratory Complications (SPORC-2) to predict the requirement for early postoperative tracheal re-intubation: a hospital registry study

Postoperative pulmonary complications are associated with an increase in mortality, morbidity and healthcare utilisation. The Agency for Healthcare Research and Quality recommends risk assessment for postoperative respiratory complications in patients undergoing surgery. In this hospital registry study of adult patients undergoing non-cardiac surgery between 2005 and 2017 at two independent healthcare networks, a prediction instrument for early postoperative tracheal re-intubation was developed and externally validated. This was based on the development of the Score for Prediction Of Postoperative Respiratory Complications. For predictor selection, stepwise backward logistic regression and bootstrap resampling were applied. Development and validation cohorts were represented by 90,893 patients at Partners Healthcare and 67,046 patients at Beth Israel Deaconess Medical Center, of whom 699 (0.8%) and 587 (0.9%) patients, respectively, had their tracheas re-intubated. In addition to five pre-operative predictors identified in the Score for Prediction Of Postoperative Respiratory Complications, the final model included seven additional intra-operative predictors: early post-tracheal intubation desaturation; prolonged duration of surgery; high fraction of inspired oxygen; high vasopressor dose; blood transfusion; the absence of volatile anaesthetic use; and the absence of lung-protective ventilation. The area under the receiver operating characteristic curve for the new score was significantly greater than that of the original Score for Prediction Of Postoperative Respiratory Complications (0.84 [95%CI 0.82-0.85] vs. 0.76 [95%CI 0.75-0.78], respectively; p < 0.001). This may allow clinicians to develop and implement strategies to decrease the risk of early postoperative tracheal re-intubation.