The Airtraq™ laryngoscope as a first choice for parturients with an expected difficult airway

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.

Obstetric Anaesthetists' Association and Difficult Airway Society guidelines for the management of difficult and failed tracheal intubation in obstetrics

The Obstetric Anaesthetists' Association and Difficult Airway Society have developed the first national obstetric guidelines for the safe management of difficult and failed tracheal intubation during general anaesthesia. They comprise four algorithms and two tables. A master algorithm provides an overview. Algorithm 1 gives a framework on how to optimise a safe general anaesthetic technique in the obstetric patient, and emphasises: planning and multidisciplinary communication; how to prevent the rapid oxygen desaturation seen in pregnant women by advocating nasal oxygenation and mask ventilation immediately after induction; limiting intubation attempts to two; and consideration of early release of cricoid pressure if difficulties are encountered. Algorithm 2 summarises the management after declaring failed tracheal intubation with clear decision points, and encourages early insertion of a (preferably second-generation) supraglottic airway device if appropriate. Algorithm 3 covers the management of the 'can't intubate, can't oxygenate' situation and emergency front-of-neck airway access, including the necessity for timely perimortem caesarean section if maternal oxygenation cannot be achieved. Table 1 gives a structure for assessing the individual factors relevant in the decision to awaken or proceed should intubation fail, which include: urgency related to maternal or fetal factors; seniority of the anaesthetist; obesity of the patient; surgical complexity; aspiration risk; potential difficulty with provision of alternative anaesthesia; and post-induction airway device and airway patency. This decision should be considered by the team in advance of performing a general anaesthetic to make a provisional plan should failed intubation occur. The table is also intended to be used as a teaching tool to facilitate discussion and learning regarding the complex nature of decision-making when faced with a failed intubation. Table 2 gives practical considerations of how to awaken or proceed with surgery. The background paper covers recommendations on drugs, new equipment, teaching and training.

Video laryngoscopes and the obstetric airway

The pitfalls surrounding securing the airway in the obstetric patient are well documented. From Tunstall's original failed intubation drill onwards, there has been progress both in recognition of the difficulties of airway management in the pregnant patient and development of algorithms to enhance patient safety. Current trends in obstetric anaesthesia have resulted in a significant decrease in exposure of anaesthetists, especially trainees, to caesarean section under general anaesthesia, compounding the difficulties in safely managing the airway. Video laryngoscopes have recently appeared in airway algorithms. They improve glottic visualisation and are useful in the management of the difficult non-obstetric airway, including those in morbidly obese patients and in the setting of a rapid-sequence induction. There is growing interest in the potential use of video laryngoscopes in the obstetric population and as a teaching tool to maximise training opportunities.