Difficult intubation is experienced more frequently in obstetric units (7.9%) than in the operating suite (2.5%) [1,2]. Difficult intubation has been identified as a major contributory factor to anaesthetic related maternal morbidity and mortality [2-8]. The American Society of Anesthesiologists (ASA) Task Force on the management of a difficult airway states that availability of equipment for the management of a difficult airway is associated with reduced maternal complications and also recommends that labour and delivery units should have equipment readily available to manage airway emergencies . However, a recent survey of German Obstetric Units demonstrated considerable variation in the availability of difficult airway equipment . To date there has been no evaluation of the difficult airway equipment available in Irish Obstetric Units, whether they are stand-alone units or obstetric units within General Hospitals. The purpose of our survey, therefore, was to describe the availability of difficult airway equipment in all Irish Obstetric Units.
All obstetric units in the Republic of Ireland listed in the Irish Medical Directory were surveyed. This telephone survey was carried out over a 3-day period in September 2002.
A questionnaire was completed based on responses provided by the consultant or senior clinical nurse manager on duty. If the appropriate person was unavailable or did not have the information immediately to hand a second telephone call was made at a later date.
All respondents were asked initially the annual birth rate at their institution and then whether the following items were located within the actual environs of the obstetric unit:
Basic airway equipment:
- (a) Curved and straight laryngoscope blades
- (b) Gum elastic bougie
- (c) Stylet
- (d) McCoy laryngoscope
Alternative ventilation equipment:
(a) Laryngeal mask airway
(b) Needle cricothyroidotomy kit
(c) Combitube® (ETC; Kendall-Sheridan Catheter Corp., Argyle, NY, USA)
Alternative intubation equipment:
- (a) Surgical airway device
- (b) Retrograde intubation kit
- (c) Intubating laryngeal mask
- (d) Fibre-optic bronchoscope
- (e) Lighted stylet
We also asked if any of the emergency departments held: end-tidal carbon dioxide (ETCO2) monitor, a difficult airway trolley and any other airway device, not mentioned in the questionnaire.
All of the 18 obstetric units contacted responded to our survey. The results of the survey are summarized in Table 1. The annual birth rate at the units surveyed ranged from 1200 to 8000. All of the obstetric units contacted had at least one alternative device on site for both ventilation and intubation. The most common alternative ventilation device was the laryngeal mask (100%). With regard to alternative intubating devices only the surgical airway device was commonly available (83.3%). Nine (50%) of the obstetric units had an intubating laryngeal mask airway, while a fibre-optic bronchoscope was present in seven (38.8%) obstetric units.
An ETCO2 monitor was available on site in 17 (94.4%) units, whilst 12 (66.6%) had their difficult airway equipment in a specific difficult airway trolley. Regarding any device not mentioned on the questionnaire one unit stated that they had a hollow gum elastic bougie through which oxygen could be insufflated.
The most important finding of this study is that all the obstetric units in the Republic of Ireland had at least one alternative device for both ventilation and intubation. This finding is significant as the incidence of failed intubation in the obstetric setting is estimated to be as frequent as one in 300-500 and it occurs seven to eight times more often in parturients than other patients [11,12].
The finding that all Irish Obstetric Units hold alternative ventilation and intubation devices is different to a survey carried out in Germany  where although alternative ventilation equipment was present in more than 90% of responding institutions, alternative intubation equipment was present in approximately 86%.
The most common alternative ventilation device available in Irish Obstetric Units was the laryngeal mask, which was present in all 18 (100%) of the obstetric units surveyed. This is appropriate as the laryngeal mask is now a well-established alternative to bag and mask ventilation and its use in emergency airway management is advocated by both the ASA Task Force and the European Resuscitation Council [9,13]. Moreover the laryngeal mask has been shown to be an effective airway device in elective Caesarean section in healthy patients .
The most common alternative intubating device was the surgical airway, available in 15 (83%) of the obstetric units and the only alternative intubating device in 8 (44.4%) of the units surveyed. This last finding is somewhat disturbing as it is unlikely that anaesthetic or indeed obstetric personnel will be very experienced in use of surgical airway devices.
The intubating laryngeal mask was present in only nine (50%) of the obstetric units surveyed. Studies have shown this to be a valid alternative device for both ventilation and intubation with a high insertion success rate for even inexperienced personnel [15,16]. It has been shown to have few side-effects . The intubating laryngeal mask is a recent addition to recommendations of the contents of a difficult airway trolley . Due to their experience with the laryngeal mask, it is likely that Irish anaesthetists will be more successful in managing a difficult airway using an intubating laryngeal mask than a surgical airway device. Due to this we believe the intubating laryngeal mask to be the best available option as an alternative intubating device.
We found that 17 (94.4%) obstetric units had ETCO2 monitors available. ETCO2 monitoring is recognized as an important tool in confirmation of correct tracheal tube placement and it is strongly recommended that an ETCO2 detector be present wherever intubations are likely to take place [9,13,17].
Twelve (66.6%) obstetric units house their difficult airway equipment in a portable trolley. The storage of all necessary difficult airway equipment in such a unit has been advocated to ensure its rapid deployment to any area where it is required .
In summary, Irish Obstetric Units are well equipped according to the international guidelines for difficult intubation equipment. However, we believe that this situation could be further improved by training inexperienced anaesthetists in the use of the intubating laryngeal mask and by the increased use of portable trolleys.
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