Dexmedetomidine, high-flow nasal oxygen and sugammadex-reversal of rocuronium: overcoming anaesthetic challenges in a parturient with congenital muscular dystrophy presenting for caesarean section

Comparison of videolaryngoscopy and direct laryngoscopy for tracheal intubation in obstetrics: a mixed-methods systematic review and meta-analysis

PURPOSE

The incidence of difficult and failed intubation is higher in obstetrical patients than in the general population because of anatomic and physiologic changes in pregnancy. Videolaryngoscopy improves the success rate of intubation and reduces complications when compared with direct laryngoscopy in adults; however, it is not known whether this extends to obstetrical surgery. The aim of this study was to examine the efficacy, efficiency, and safety of videolaryngoscopy compared with direct laryngoscopy in obstetrics.

SOURCE

Central, CINAHL, Embase, MEDLINE and Web of Science databases were searched from inception to 27 May 2020 with no restrictions. Inclusion criteria included randomized-controlled trials (RCTs), observational studies, case series, and case reports that reported the application of videolaryngoscopy to intubate the trachea in pregnant patients having general anesthesia.

PRINCIPAL FINDINGS

Overall, four RCTs with 428 participants, nine observational studies, and 35 case reports/series with 100 participants were included. On meta-analysis of three trials, the co-primary outcomes of first-attempt success rate (risk ratio, 1.02; 95% confidence intervals [CI], 0.98 to 1.06; P = 0.29; I2 = 0%) and time to tracheal intubation (mean difference, 1.20 sec; 95% CI, -6.63 to 9.04; P = 0.76; I² = 95%) demonstrated no difference between videolaryngoscopy and direct laryngoscopy in parturients without difficult airways. Observational studies and case reports underline the role of videolaryngoscopy as a primary choice when difficulty with tracheal intubation is expected or as a rescue modality in difficult or failed intubations.

CONCLUSIONS

Evidence for the utility of videolaryngoscopy continues to evolve but supports its increased adoption in obstetrics where videolaryngoscopes should be immediately available for use as a first-line device.

TRIAL REGISTRATION

PROSPERO (CRD42020189521); registered 6 July 2020.

The efficacy of high flow nasal oxygenation for maintaining maternal oxygenation during rapid sequence induction in pregnancy: A prospective randomised clinical trial

BACKGROUND

High-flow nasal oxygenation (HFNO) for pre-oxygenation in rapid sequence induction (RSI) has only been assessed in volunteer parturients without intubation.

OBJECTIVES

To evaluate the efficacy of HFNO in comparison with the conventional facemask for oxygenation during RSI for caesarean section under general anaesthesia.

SETTING

Operating room in a tertiary hospital.

DESIGN

Prospective randomised, controlled study.

PARTICIPANTS

Thirty-four healthy parturients undergoing general anaesthesia for caesarean section.

INTERVENTIONS

Parturients were randomly assigned to HFNO or standard facemask (SFM) group.

MAIN OUTCOME MEASURES

The primary outcome measure was the PaO2 immediately after intubation. Secondary outcomes included lowest saturation throughout the intubation procedure, end-tidal oxygen concentration (EtO2) on commencing ventilation, blood gas analysis (pH, PaCO2), fetal outcomes and intubation-related adverse events.

RESULTS

PaO2 in the HFNO group was significantly higher than that in SFM group (441.41 ± 46.73 mmHg versus 328.71 ± 72.80 mmHg, P < 0.0001). The EtO2 concentration in the HFNO group was higher than that in the SFM group (86.71 ± 4.12% versus 76.94 ± 7.74%, P < 0.0001). Compared to baseline, PaCO2 immediately after intubation also increased significantly in both groups (HFNO group: 30.87 ± 2.50 mmHg versus 38.28 ± 3.18 mmHg; SFM group: 29.82 ± 2.57 mmHg versus 38.05 ± 5.76 mmHg, P < 0.0001), but there was no difference in PaCO2 between the two groups. There was no difference in lowest saturation, intubation times, duration of apnoea, pH value or fetal outcomes.

CONCLUSIONS

Compared with SFM, HFNO provided a higher PaO2 and EtO2 immediately after intubation in parturients. HFNO is safe as a method of oxygenation during RSI in parturients undergoing general anaesthesia for caesarean section.

TRIAL REGISTRATION

Clinical trial ChiCTR1900023121.

Use of transnasal humidified rapid-insufflation ventilatory exchange (THRIVE) to facilitate the management of subglottic stenosis in pregnancy

Subglottic stenosis is a rare condition. Diagnosis is often delayed as symptoms are attributed to other causes, such as asthma. This problem may be compounded in pregnancy when dyspnoea may be attributed to normal physiological changes. In respiratory compromise, surgical intervention may be required and airway management is challenging as endotracheal intubation may be traumatic or, in severe cases, impossible. Transnasal humidified rapid-insufflation ventilatory exchange (THRIVE) is a novel open-airway apnoeic technique using high-flow nasal oxygen. It does not expose the patient to the risks of jet ventilation, nor does it require the placement of an airway device to effectively oxygenate the patient. In pregnancy, elevation of maternal carbon dioxide is of particular concern as it may result in a worsening fetal acidosis. While THRIVE has been shown to provide some clearance of carbon dioxide, a patent airway is required for it to function effectively. In this case report we describe the management of a pregnant patient who underwent balloon dilatation for severe subglottic stenosis at 23 weeks' gestation using THRIVE and we summarise the evidence supporting the use of this new technique in pregnant women.

Transient Asystole after Sugammadex Administration for Immediate Reversal of Deep Blockade while on Dexmedetomidine Infusion in a Super Obese Patient

Sugammadex is increasingly used to reverse aminosteroid neuromuscular blocking agents. Dosing is calculated based on actual body weight, even for those who are obese. We report a case where a super obese patient (BMI 58.5 kg/m²) developed asystole, following coadministration with dexmedetomidine, for rapid reversal after deep blockade. Although 16mg/kg of actual body weight is recommended for prompt reversal of deep blockade, dosing adjustments may be prudent in the obese population, especially when used in conjunction with other negative chronotropic agents.