Efficacy of high-flow nasal oxygenation compared with tracheal intubation for oxygenation during laryngeal microsurgery: a randomised non-inferiority study.

BACKGROUND: Oxygenation via a high-flow nasal cannula (HFNC) can be an alternative to tracheal intubation during short apnoeic procedures. This randomised, non-inferiority study assessed the efficacy of HFNC compared with tracheal intubation in laryngeal microsurgery. METHODS: Patients (≥20 yr old) undergoing laryngeal microsurgery under general anaesthesia and neuromuscular blockade were randomised to either the HFNC or tracheal intubation groups. The primary endpoint was lowest pulse oxygen saturation (SpO2) during the first 30 min of surgery. Secondary endpoints included incidence of desaturation (SpO2 <95%), hypercarbia (transcutaneous carbon dioxide [CO2] ≥8.7 kPa), and rescue intervention. RESULTS: Amongst 130 patients randomised, 118 were included in the analysis. The lowest SpO2 was 100 (98-100)% in the HFNC group (n=56) and 100 (100-100)% in the tracheal intubation group (n=62), with a mean difference of -1.4% (95% confidence interval: -2.4% and -0.3%), failing to confirm non-inferiority with a non-inferiority margin of 2%. The peak transcutaneous CO2 and end-tidal CO2 at the end of surgery were higher in the HFNC group compared with the tracheal intubation group. Incidences of desaturation, hypercarbia, and rescue intervention were more frequent in patients receiving HFNC compared with tracheal intubation. CONCLUSIONS: HFNC oxygenation was not non-inferior to tracheal intubation for maintaining oxygen saturation during laryngeal microsurgery. Considering more frequent desaturation, hypercarbia, and requirement for rescue intervention compared with tracheal intubation, HFNC should be used with cautious monitoring even for short duration airway surgery. CLINICAL TRIAL REGISTRATION: NCT03629353.

The velocity curve of the clotting waveform of rotational thromboelastometry predicts bleeding after cardiac surgery but conventional rotational thromboelastometric parameters do not.

BACKGROUND: Early detection of a risk of postoperative bleeding is essential in cardiac surgery patients. The aim of the present study was to evaluate the utility of the first derivative curve (the V-curve) of the clotting waveform of rotational thromboelastometry (ROTEM) in terms of predicting bleeding after cardiac surgery. METHODS: We retrospectively analysed 534 cardiac surgery patients. We used the chest tube output during the stay in the intensive care unit to divide patients into a higher blood loss group (HBL group; the fourth quartile) and a lower blood loss group (LBL group; the lower quartiles). We performed multivariable logistic regression using the V-curve parameters and potential confounders including conventional ROTEM parameters. RESULTS: In the multivariable model, the adjusted odds ratios for HBL of patients with a lower maximum clotting velocity (MaxVel ≤9 mm*100 s-1) as revealed by extrinsically activated ROTEM (EXTEM), and the area under the velocity curve (AUC ≤988 mm*100) of the fibrin-based extrinsically activated ROTEM (FIBTEM), both measured at skin closure in the end of surgery, were 1.78 (95% CI 1.03 to 3.07) and 2.14 (95% CI 1.20 to 3.82), respectively. However, conventional ROTEM parameters were not included in the final model. Additionally, lower EXTEM MaxVel and FIBTEM AUC values were associated with the need for a higher transfusion volume, longer postoperative intensive care unit and hospital stays, and more frequent re-exploration to control bleeding. CONCLUSIONS: The ROTEM V-curve parameters can predict postoperative bleeding and clinical outcomes after cardiac surgery.

Intraoperative anaphylaxis to neuromuscular blocking agents: the incidence over 9 years at two tertiary hospitals in South Korea: A retrospective observational study.

BACKGROUND: Intraoperative anaphylaxis to neuromuscular blocking agents (NMBAs) is a rare event that is unpredictable and potentially life threatening. Most of the previous reports on such intraoperative anaphylaxis used market share surveys or self-reported data to estimate the incidence. OBJECTIVE: To determine the incidences of intraoperative anaphylaxis to NMBAs using electronic medical records. DESIGN: A retrospective observational study. SETTING: Two tertiary hospitals in South Korea. PATIENTS: This study involved patients exposed to NMBAs during anaesthesia between 1 January 2005 and 31 May 2014. Nineteen episodes were deemed to be intraoperative anaphylaxis to NMBAs. MAIN OUTCOME MEASURES: We calculated the incidences of intraoperative anaphylaxis to NMBAs. Exposure to the agents was determined from intraoperative records maintained in an electronic medical recording system. An anaphylactic reaction was determined from both clinical signs and the results of skin tests. RESULTS: Over 9 years, 729 429 patients were exposed to NMBA, the most frequently used being rocuronium [425 047 (58.3%)] and vecuronium [274 801 (37.7%)]. The overall incidence of intraoperative anaphylaxis was 2.6 per 100 000 (19 cases), and was higher with rocuronium (16 cases, 3.8 per 100 000) than with vecuronium (two cases, 0.7 cases per 100 000), P = 0.014. Comparing the first 3 years with the last 6 years, the incidence of intraoperative rocuronium anaphylaxis appeared to increase 1.4-fold (P = 0.006). CONCLUSION: Among commonly used NMBAs, rocuronium appears to have the highest incidence of anaphylaxis. Our findings suggest that future prospective investigation for NMBA-induced anaphylaxis should use internationally agreed skin test protocols.