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

Abstract

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.

Figure 1

Master algorithm – obstetric general anaesthesia and failed intubation. The yellow diamond represents a decision-making step. P_max, maximal inflation pressure; CICO, ‘can't intubate, can't oxygenate’. The algorithms and tables are reproduced with permission from the OAA and DAS and are available online in pdf and PowerPoint formats.

Figure 2

Algorithm 1 – safe obstetric general anaesthesia. WHO, World Health Organization; F_ETO₂, end-tidal fraction of oxygen; P_max, maximal inflation pressure. The algorithms and tables are reproduced with permission from the OAA and DAS and are available online in pdf and PowerPoint formats.

Figure 3

Table 1 – wake or proceed with surgery? Criteria to be used in the decision to wake or proceed following failed tracheal intubation. In any individual patient, some factors may suggest waking and others proceeding. The final decision will depend on the anaesthetist's clinical judgement. The algorithms and tables are reproduced with permission from the OAA and DAS and are available online in pdf and PowerPoint formats.

Figure 4

Algorithm 2 – obstetric failed tracheal intubation. The yellow diamonds represent decision-making steps; the lower right decision step links to Table 1 (Fig.3). The boxes at the bottom link to Table 2 (Fig 6). The algorithms and tables are reproduced with permission from the OAA and DAS and are available online in pdf and PowerPoint formats.

Figure 5

Algorithm 3 – ‘can't intubate, can't oxygenate’. The yellow diamonds represent decision-making steps; the lower right decision step links to Table 1 (Fig.3). The boxes at the bottom link to Table 2 (Fig. 6). ENT, ear, nose and throat. The algorithms and tables are reproduced with permission from the OAA and DAS and are available online in pdf and PowerPoint formats.

Figure 6

Table 2 – management after failed tracheal intubation. i.v., intravenous. The algorithms and tables are reproduced with permission from the OAA and DAS and are available online in pdf and PowerPoint formats.