2. extubation strategy involving reversible extubation complications encountered during reestablishment of
(14 ā21). This is the first report to provide details, in a the airway. Hypoxemia was defined as a desaturation
relatively large cohort of difficult airway patients, on nadir of Spo2 Ļ½90% and severe hypoxemia as Spo2
the reintubation first-pass success rate, reasons for Ļ½70%. Reintubation of the patientās trachea was indi-
reintubation failure, and any complications associated vidualized for each patient and at the discretion of the
with reestablishment of the airway after extubation. ICU and anesthesia teams. Typically, shortness of
Further, this is the first report describing extensive use breath, tachypnea, worsening oxygen saturations, stri-
of both the smaller adult 11F and the medium-sized dor, increased work of breathing, and failure of pul-
adult 14F AEC. monary toilet despite therapeutic assistance by the
nursing and respiratory therapy staff contributed to
the decision for reintubation.
METHODS Data were analyzed using SPSS 12 (SPSS Inc.,
In an observational analysis, a difficult airway Chicago, IL). The contingency ā¹2 test was used for
quality improvement database was reviewed for pa- categorical variables in comparing complications be-
tients who were extubated over an AEC for a known tween patients with and without the AEC in place yet
or presumed difficult airway in the OR, the postanes- requiring reintubation of the trachea. Statistical sig-
thesia care unit (PACU), or the intensive care unit nificance was accepted at P Ļ½ 0.05.
(ICU). Data were collected by the author prospectively
and entered into a Microsoft Excel spreadsheet
(1998 ā2002); then, the database was transferred to and RESULTS
maintained in an SPSS statistical package data sheet In the review period, 354 patients with a known or
(2002ā2006). Patients were cared for directly by the suspected difficult airway, based on previous airway
author or by members of the anesthesia airway team. encounters and current physical examination, had
If observation of postextubation patients extended access to their trachea maintained by an indwelling
beyond regular working hours (evening and night AEC after extubation. Other methods of staged extuba-
shifts), the author collected and verified data through tion (transition from ETT to laryngeal mask airway
ICU care team interviews and review of the medical [LMA] or bronchoscopic-assisted extubation) were rela-
records. The hospitalās IRB waived the need for in- tively few in the ICU setting and were not reviewed.
formed consent. After extubation over an AEC, each patient re-
Over a 9-yr period, 354 patients were extubated mained in a monitored environment (the ICU setting,
with a Cook AEC (3.7 mm E.D.-11F, 4.7 mm-14F or 6.3 the PACU, or transition from the OR to the PACU).
mm-19F, Cook Critical Care, Bloomington, IN) left in The AEC remained in place for a mean of 3.9 h (range,
the trachea for a potential reversible extubation as part 5 min to 72 h). All patients in the first group who
of a staged extubation strategy. The AEC remained in underwent an AEC-assisted reintubation did so
the trachea until reintubation was considered unlikely within 24 h after extubation. The second group did not
for each individual patient by the ICU and anesthesia have the AEC in position at the time of their reintu-
airway team. Reintubation of the trachea was man- bation. The AEC size used for the extubation varied:
aged by the anesthesia airway team (an anesthesia 11F (151 patients typically Ļ½5Š5Š tall, 46%), 14F (165
attending physician alone or an anesthesia resident patients typically taller than 5Š5Š, 50%) and 19F (13
[CA-2, CA-3] directly supervised by the attending patients taller than 5Š10Š, 4%). The location of
staff) at the patientās bedside. The anesthesia team the patient at the time of tracheal extubation included
membersā experiences with reintubation over an in- the OR (17 postsurgical patients extubated at the
dwelling AEC varied, although they routinely per- conclusion of their anesthesia), the PACU (24 postsur-
formed tracheal intubation over a bougie airway catheter gical patients extubated after their transfer from the
or tracheal tube exchanges over an AEC. OR to the PACU for postanesthesia recovery), and the
Patient analysis was performed on the primary ICU (288 patients). Most of the ICU patients (75%) had
group, which included patients with an indwelling been intubated for Ļ¾48 h, and many were in the
AEC, who required reintubation within 24 h and a recovery phase of resolving pneumonias, congestive
secondary group of patients who had initially had an heart failure, tracheobronchitis, neuro/mental status
indwelling AEC in the postextubation period but who alterations, and other maladies placing them at high
then underwent removal of the AEC based on the risk for potential extubation failure. Seventy-two per-
presumed tolerance of the extubated state. Patients in cent of the 354 patients had a known difficult airway
the secondary group subsequently required reintuba- based on a history of difficult airway management
tion within 7 days of tracheal extubation. These two requiring multiple conventional attempts (Õ3) or re-
groups were reviewed for the time from extubation to quiring an accessory airway device to secure the
reintubation, the number of attempts required to airway in the emergency room, the OR, or a remote
reintubate the trachea (with and without the AEC in location intubation during the current hospitalization.
place), the incidence of hypoxemia during reintuba- The remaining patients, 28%, had a suspected difficult
tion, the method used to resecure the airway, and any airway based on their current physical examination
1358 Extubation of the Difficult Airway ANESTHESIA & ANALGESIA
4. Table 3. Complications of the Reintubation Procedure
AEC present AEC absent
(n ā«)15 Ųā¬ (n ā«)63 Ųā¬ P
First-pass success rate for reintubation 87% 14% (5) Ļ½0.02
Hypoxemia during reintubation (Spo2 Ļ½90%) 8%b (4) 50% (18) Ļ½0.01
Severe hypoxemia during reintubation (Spo2 Ļ½70%) 6%a(3) 19% (7) 0.05
Bradycardia (heart rate Ļ½40) with hypotension 4% (2) 14% (5) Ļ½0.05
Multiple intubation attempts (Õ3) including the 10%b (5) 77% (28) Ļ½0.02
placement of an accessory airway device
Esophageal intubation 0 18% (6)
Rescue airway device/technique 6%a (3) 90% (32) Ļ½0.01
a
Includes the AEC failures due to inability to pass ETT into trachea (1 case) and proximal migration of the AEC out of the trachea (3 cases).
AEC Ļ airway exchange catheter; ETT Ļ endotracheal tube.
or suspected difficult airway,ā since the vast majority the skills and preferences of the practitioner (1). Rein-
required multiple attempts to resecure the airway tubation of the trachea in the known or suspected
(three or more attempts with laryngoscopy plus the difficult airway patient appears fraught with compli-
accessory device/technique, 77%) when compared cations, as illustrated in this study by the group of
with only one patient with the indwelling AEC who patients who underwent extubation of their trachea
required three attempts. Table 2 illustrates the conven- over an AEC, had it subsequently removed when the
tional and accessory airway devices that were re- reintubation risk was presumed to be low, yet later
quired to assist the practitioner in resecuring the suffered extubation intolerance and were reintubated.
patientsā airways. Postextubation hypoventilation, airway compro-
The 14% first-pass reintubation success rate (first mise, ventilation-perfusion inequalities, and obstruc-
attempt with direct laryngoscopy or accessory device) tion due to fatigue may afflict the patient in the OR, in
in the non-AEC group was dwarfed by the AEC- the PACU, and in particular in the ICU (3,4). Continu-
assisted first-pass success rate of 87% (Table 3). Nearly ous access to the airway can be maintained via an AEC
all (90%) of the non-AEC group required an accessory with the proximal tip secured to the patientās clothing
airway device or an advanced technique to success- or forehead (waterproof adhesive tape). This is well
fully reestablish the airway (Table 3). Of note, after tolerated by most patients (90%) and thus is a valuable
failure to intubate the trachea in four patients, despite option, considering a reintubation rate that varies
concerted attempts with accessory devices, a surgical from 0.4% to 25% in the various PACU and ICU
airway was required. Two of these four patients populations (3ā7,14 ā21).
received bag-mask ventilation during the establish- Currently, there are no evidence-based guidelines
ment of the surgical airway, and two patients had regarding the optimal period of time for maintaining
concurrent and successful ventilation and oxygen- airway access postextubation via an indwelling AEC.
ation via an LMA during placement of the surgical Experts have suggested at least 30 ā 60 min or until the
airway. likelihood of reintubation is minimized (3,5,6,22ā24).
Oxygen desaturation in the non-AEC group was Unfortunately, our database suggests that a minimum
common during the reintubation process, with the of 30 ā 60 min would underestimate the need for a
nadir of Ļ½90% Spo2 occurring in 50% of the patients; reversible extubation in a significant number of these
40% of these suffered severe hypoxemia (Spo2 Ļ½70%, high-risk patients. Moreover, the potential for changes
Table 3). Esophageal intubation was more common in in the patientās clinical status makes it difficult to
the non-AEC group (18% to 0%), as was hypoxemia- predict when the need for reintubation is minimized.
driven bradycardia with profound hemodynamic This may be particularly true in the ICU population,
deterioration. Table 3 compares the various complica- who may suffer acute alterations in their cardiopul-
tions of the reintubation procedure between those monary, metabolic, or neurological status, or other
reintubated with and without an indwelling AEC.
critical medical/surgical issues that may influence
their tolerance of extubation.
DISCUSSION If the intolerance of the extubated state is based
In the high-risk extubation patient with known or principally on the presence or potential accumulation
suspected airway management difficulties, develop- of periglottic edema, then the patient may benefit from
ment of a strategy to maintain access to the airway and extending the duration of the indwelling AEC to
to offer the safety of reversibility if the extubated state 60 ā120 min. Periglottic edema contributing to airway
is not tolerated should be considered (1). This strategy compromise often occurs immediately upon extuba-
will depend, in part, on the surgical and medical tion or within 10 ā 45 min of extubation, although it
conditions of the patient, on the previous airway has been noted that symptomatic laryngeal edema
procedures and current airway status, as well as on may develop as late as 8 h postextubation (14,15).
1360 Extubation of the Difficult Airway ANESTHESIA & ANALGESIA
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1362 Extubation of the Difficult Airway ANESTHESIA & ANALGESIA