Mortality with Airway Events and General Anesthesia in Parturients
While specific mortality data from the past 5 years is not directly reported in the available evidence, airway-related complications remain a critical concern in obstetric anesthesia, with failed intubation historically identified as the most common contributory factor to anesthetic-related maternal death. 1
Current Mortality Context
The available guidelines and literature from 2015-2025 emphasize prevention and management strategies rather than providing updated mortality statistics. However, the evidence consistently highlights that:
Anesthesia remains the seventh leading cause of maternal mortality in the United States, with failure to appropriately manage difficult or failed intubation increasing the risk of hypoxemic cardiopulmonary arrest and pulmonary aspiration. 2
Nearly 30% of all adverse anesthetic events occur at the end of anesthesia or during recovery, making extubation a particularly vulnerable period. 1
Difficult tracheal intubation, often unexpected, has been identified as the commonest contributory factor to anesthetic-related maternal death. 3
Key Risk Factors for Airway-Related Mortality
The evidence identifies specific anatomic and physiological factors that increase mortality risk:
Mallampati class 3 or 4 is significantly associated with difficult intubation in obstetric populations. 4, 3
Short neck is a well-established predictor of difficult laryngoscopy and intubation, with multivariate analysis confirming it as an independent risk factor. 4, 3
Obesity increases difficult intubation incidence to 4.2% and difficult mask ventilation to 2.9%, though its association is partially mediated through short neck. 4, 3
Neck circumference ≥42 cm significantly increases risk of both difficult mask ventilation and intubation. 4
Protruding maxillary incisors and receding mandible remain independent risk factors after multivariate analysis. 3
Prevention Strategies to Reduce Mortality
The most recent guidelines (2020) emphasize that mortality prevention requires systematic antenatal planning rather than reactive management. 1
Antenatal Planning Algorithm
For women with anticipated difficult airways, multidisciplinary planning must include: 1
Assessment of clinical characteristics: Document specific airway risk factors including Mallampati grade, neck movement, mouth opening, thyromental distance, and jaw protrusion. 5
Equipment and personnel availability: Ensure requisite advanced airway equipment and appropriately skilled anaesthetists are available, particularly for out-of-hours emergencies. 1
Timing and mode of delivery decision: If adequate equipment, personnel, or skills are lacking for safe out-of-hours airway management, elective caesarean section should be performed during regular hours to avoid emergency airway management. 1
Intrapartum Management to Prevent Mortality
If labour is allowed for women with anticipated difficult airways: 1
Communicate the airway plan with all staff and ensure it is readily available in the woman's maternity notes. 1
Restrict oral intake to clear fluids only and provide stomach acid neutralization. 1, 5
Establish effective regional analgesia suitable for conversion to surgical anaesthesia, as this reduces the likelihood that general anaesthesia will be required. 1
Administer H2-receptor antagonists every 6 hours during labour for women at high risk of requiring general anaesthesia. 5
General Anesthesia Approach When Required
When general anaesthesia cannot be avoided, a risk assessment must determine whether safe airway management can be achieved after induction. 1
Decision Algorithm for Airway Management
If safe airway management after induction is uncertain, awake tracheal intubation must be used: 1, 5, 4
Videolaryngoscopy is the preferred first-line approach for awake intubation, with higher success rates and fewer optimizing maneuvers required. 4
Flexible bronchoscopic intubation is considered the safest method for extreme airway difficulty, though it requires significantly longer time than rapid sequence induction. 1, 4
If general anaesthesia with rapid sequence induction is deemed safe: 1, 5
Ultrasound should be used to mark the cricothyroid membrane before induction. 1
Position the patient in the "ramped" position (head-elevated, semi-seated) to optimize laryngoscopic view. 5, 4
Have videolaryngoscope as the primary device, with supraglottic airway devices and front-of-neck access equipment immediately available. 5, 4
Apply high-flow nasal oxygen or simple nasal cannula to maintain oxygenation during intubation attempts. 4
Failed Intubation Management
Before induction, the anaesthetist must discuss with the obstetric team whether to wake the woman or continue anaesthesia if tracheal intubation fails. 5
If intubation fails but ventilation is adequate: 4
- Insert a supraglottic airway device immediately.
- Second-generation SGA devices have been used successfully in 7,722 patients with only seven failed insertions and no cases of pulmonary aspiration. 6
If cannot intubate, cannot ventilate (CICV) occurs: 4
- Immediate front-of-neck access is required.
- Surgical cricothyroidotomy is the definitive technique.
Extubation Considerations
Extubation represents a high-risk period, with regurgitation occurring in five of 1,095 cases at extubation in one series. 1
Key extubation safety measures: 1
Perform extubation only when the woman is awake, responsive to commands, maintaining oxygen saturation, and generating satisfactory tidal volume.
Consider head-up position for extubation, which aids airway patency, respiratory function, and airway access, especially in obese parturients. 1
If re-intubation might be difficult (e.g., laryngeal edema in pre-eclampsia or after traumatic intubation), perform supplementary airway evaluation by direct laryngoscopy or fibreoptic examination, or confirm an audible leak around the tracheal tube with cuff deflated. 1
Transfer to intensive care unit for controlled ventilation and delayed extubation may be appropriate for high-risk cases. 1
Critical Pitfalls to Avoid
Common errors that increase mortality risk: 5
Failure to recognize the need for specialized equipment and personnel for difficult airway management can lead to adverse outcomes. 5
Underestimating physiological changes of pregnancy (mucosal engorgement, friability, susceptibility to hypoxemia) complicates airway management. 5
Delaying anesthesia consultation until an emergency arises limits options and increases risks. 5
Late antenatal referral to the anaesthetic service, with some patients referred only after a decision for emergency surgery has been made. 1
Follow-up and Documentation
Following difficult or failed intubation: 1
Perform a follow-up visit for all patients who underwent general anaesthesia, with direct enquiry about awareness during anaesthesia (more frequent if intubation was difficult). 1
Document full details about ease of mask ventilation, grade of laryngoscopy, airway equipment used, complications, and other information for future anaesthetics. 1
Provide a letter to the patient and general practitioner using a standardized form (DAS alert form), including the READ code if failed intubation occurred. 1
For serious but rare morbidity (trauma or perforation to larynx, pharynx, or oesophagus presenting with pyrexia, retrosternal pain, and surgical emphysema), urgent review by an ear, nose and throat specialist is required due to high associated mortality. 1