Effect of Remifentanil vs Neuromuscular Blockers During Rapid Sequence Intubation on Successful Intubation Without Major Complications Among Patients at Risk of Aspiration: A Randomized Clinical Trial

Remifentanil for tracheal intubation without neuromuscular blocking drugs in adult patients: a systematic review and meta-analysis

There is increasing interest in the use of short-acting opioids such as remifentanil to facilitate tracheal intubation. The aim of this systematic review was to determine the efficacy and safety of remifentanil for tracheal intubation compared with neuromuscular blocking drugs in adult patients. We conducted a systematic search for randomised controlled trials evaluating remifentanil for tracheal intubation. Primary outcomes included tracheal intubation conditions and adverse events. Twenty-one studies evaluating 1945 participants were included in the analysis. Use of remifentanil (1.5-4.0 μg.kg-1) showed no evidence of a difference in tracheal intubation success rate compared with neuromuscular blocking drugs (risk ratio (95%CI) 0.97 (0.94-1.01); six studies; 1232 participants; I2 28%; p = 0.16; moderate-certainty evidence). Compared with neuromuscular blocking drugs, the use of remifentanil (2.0-4.0 μg.kg-1) makes little to no difference in terms of producing excellent tracheal intubation conditions (risk ratio (95%CI) 1.16 (0.72-1.87); two studies; 121 participants; I2 31%, p = 0.54; moderate-certainty of evidence). There was no evidence of an effect between remifentanil (2.0-4.0 μg.kg-1) and neuromuscular blocking drugs for bradycardia (risk ratio (95%CI) 0.44 (0.01-13.90); two studies; 997 participants; I2 81%; p = 0.64) and hypotension (risk ratio (95%CI) 1.05 (0.44-2.49); three studies; 1071 participants; I2 92%; p = 0.92). However, the evidence for these two outcomes was judged to be of very low-certainty. We conclude that remifentanil may be used as an alternative drug for tracheal intubation in cases where neuromuscular blocking drugs are best avoided, but more studies are required to evaluate the haemodynamic adverse events of remifentanil at different doses.

Comparison of patient-controlled analgesia and sedation (PCAS) with remifentanil and propofol versus total intravenous anesthesia (TIVA) with midazolam, fentanyl, and propofol for colonoscopy

BACKGROUND

Colonoscopy is a commonly performed gastroenterological procedure in patients associated with anxiety and pain. Various approaches have been used to provide sedation and analgesia during colonoscopy, including patient-controlled analgesia and sedation (PCAS). This study aims to evaluate the feasibility and efficiency of PCAS administered with propofol and remifentanil for colonoscopy.

METHODS

This randomized controlled trial was performed in an authorized and approved endoscopy center. A total of 80 outpatients were recruited for the colonoscopy studies. Patients were randomly allocated into PCAS and total intravenous anesthesia (TIVA) groups. In the PCAS group, the dose of 0.1 ml/kg/min of the mixture was injected after an initial bolus of 3 ml mixture (1 ml containing 3 mg of propofol and 10 μg of remifentanil). Each 1 ml of bolus was delivered with a lockout time of 1 min. In the TIVA group, patients were administered fentanyl 1 μg/kg, midazolam 0.02 mg/kg, and propofol (dosage titrated). Cardiorespiratory parameters and auditory evoked response index were continuously monitored during the procedure. The recovery from anesthesia was assessed using the Aldrete scale and the Observer's Assessment of Alertness/Sedation Scale. The Visual Analogue Scale was used to assess the satisfaction of patients and endoscopists.

RESULTS

No statistical differences were observed in the Visual Analogue Scale scores of the patients (9.58 vs 9.50) and the endoscopist (9.43 vs 9.30). A significant decline in the mean arterial blood pressure, heart rate, and auditory evoked response index parameters was recorded in the TIVA group (P < 0.05). The recovery time was significantly shorter in the PCAS group than in the TIVA group (P = 0.00).

CONCLUSION

The combination of remifentanil and propofol could provide sufficient analgesia, better hemodynamic stability, lighter sedation, and faster recovery in the PCAS group of patients compared with the TIVA group.

Pre-oxygenation with high-flow oxygen through the nasopharyngeal airway compared to facemask on carbon dioxide clearance in emergency adults: a prospective randomized non-blinded clinical trial

INTRODUCTION

Before tracheal intubation, it is essential to provide sufficient oxygen reserve for emergency patients with full stomachs. Recent studies have demonstrated that high-flow nasal oxygen (HFNO) effectively pre-oxygenates and prolongs apneic oxygenation during tracheal intubation. Despite its effectiveness, the use of HFNO remains controversial due to concerns regarding carbon dioxide clearance. The air leakage and unknown upper airway obstruction during HFNO therapy cause reduced oxygen flow above the vocal cords, possibly weaken the carbon dioxide clearance.

METHODS

Patients requiring emergency surgery who had fasted < 8 h and not drunk < 2 h were randomly assigned to the high-flow group, who received 100% oxygen at 30-60 L/min through nasopharyngeal airway (NPA), or the mask group, who received 100% oxygen at 8 L/min. PaO2 and PaCO2 were measured immediately before pre-oxygenation (T0), anesthesia induction (T1), tracheal intubation (T2), and mechanical ventilation (T3). The gastric antrum's cross-sectional area (CSA) was measured using ultrasound technology at T0, T1, and T3. Details of complications, including hypoxemia, reflux, nasopharyngeal bleeding, postoperative pulmonary infection, postoperative nausea and vomiting (PONV), and postoperative nasopharyngeal pain, were recorded. The primary outcomes were PaCO2 measured at T1, T2, and T3. The secondary outcomes included PaO2 at T1, T2, and T3, CSA at T1 and T3, and complications happened during this trial.

RESULTS

Pre-oxygenation was administered by high-flow oxygen through NPA (n = 58) or facemask (n = 57) to 115 patients. The mean (SD) PaCO2 was 32.3 (6.7) mmHg in the high-flow group and 34.6 (5.2) mmHg in the mask group (P = 0.045) at T1, 45.0 (5.5) mmHg and 49.4 (4.6) mmHg (P < 0.001) at T2, and 47.9 (5.1) mmHg and 52.9 (4.6) mmHg (P < 0.001) at T3, respectively. The median ([IQR] [range]) PaO2 in the high-flow and mask groups was 404.5 (329.1-458.1 [159.8-552.9]) mmHg and 358.9 (274.0-413.3 [129.0-539.1]) mmHg (P = 0.007) at T1, 343.0 (251.6-428.7 [73.9-522.1]) mmHg and 258.3 (162.5-347.5 [56.0-481.0]) mmHg (P < 0.001) at T2, and 333.5 (229.9-411.4 [60.5-492.4]) mmHg and 149.8 (87.0-246.6 [51.2-447.5]) mmHg (P < 0.001) at T3, respectively. The CSA in the high-flow and mask groups was 371.9 (287.4-557.9 [129.0-991.2]) mm2 and 386.8 (292.0-537.3 [88.3-1651.7]) mm2 at T1 (P = 0.920) and 452.6 (343.7-618.4 [161.6-988.1]) mm2 and 385.6 (306.3-562.0 [105.5-922.9]) mm2 at T3 (P = 0.173), respectively. The number (proportion) of complications in the high-flow and mask groups is shown below: hypoxemia: 1 (1.7%) vs. 9 (15.8%, P = 0.019); reflux: 0 (0%) vs. 0 (0%); nasopharyngeal bleeding: 1 (1.7%) vs. 0 (0%, P = 1.000); pulmonary infection: 4 (6.9%) vs. 3 (5.3%, P = 1.000); PONV: 4 (6.9%) vs. 4 (7.0%, P = 1.000), and nasopharyngeal pain: 0 (0%) vs. 0 (0%).

CONCLUSIONS

Compared to facemasks, pre-oxygenation with high-flow oxygen through NPA offers improved carbon dioxide clearance and enhanced oxygenation prior to tracheal intubation in patients undergoing emergency surgery, while the risk of gastric inflation had not been ruled out.

TRIAL REGISTRATION

This trial was registered prospectively at the Chinese Clinical Research Registry on 26/4/2022 (Registration number: ChiCTR2200059192).