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Objective: To determine which bedside method of detecting inadvertent endobronchial intubation in adults has the highest sensitivity and specificity., Design: Prospective randomised blinded study., Setting: Department of anaesthesia in tertiary academic hospital., Participants: 160 consecutive patients (American Society of Anesthesiologists category I or II) aged 19-75 scheduled for elective gynaecological or urological surgery., Interventions: Patients were randomly assigned to eight study groups. In four groups, an endotracheal tube was fibreoptically positioned 2.5-4.0 cm above the carina, whereas in the other four groups the tube was positioned in the right mainstem bronchus. The four groups differed in the bedside test used to verify the position of the endotracheal tube. To determine whether the tube was properly positioned in the trachea, in each patient first year residents and experienced anaesthetists were randomly assigned to independently perform bilateral auscultation of the chest (auscultation); observation and palpation of symmetrical chest movements (observation); estimation of the position of the tube by the insertion depth (tube depth); or a combination of all three (all three)., Main Outcome Measures: Correct and incorrect judgments of endotracheal tube position., Results: 160 patients underwent 320 observations by experienced and inexperienced anaesthetists. First year residents missed endobronchial intubation by auscultation in 55% of cases and performed significantly worse than experienced anaesthetists with this bedside test (odds ratio 10.0, 95% confidence interval 1.4 to 434). With a sensitivity of 88% (95% confidence interval 75% to 100%) and 100%, respectively, tube depth and the three tests combined were significantly more sensitive for detecting endobronchial intubation than auscultation (65%, 49% to 81%) or observation(43%, 25% to 60%) (P<0.001). The four tested methods had the same specificity for ruling out endobronchial intubation (that is, confirming correct tracheal intubation). The average correct tube insertion depth was 21 cm in women and 23 cm in men. By inserting the tube to these distances, however, the distal tip of the tube was less than 2.5 cm away from the carina (the recommended safety distance, to prevent inadvertent endobronchial intubation with changes in the position of the head in intubated patients) in 20% (24/118) of women and 18% (7/42) of men. Therefore optimal tube insertion depth was considered to be 20 cm in women and 22 cm in men., Conclusion: Less experienced clinicians should rely more on tube insertion depth than on auscultation to detect inadvertent endobronchial intubation. But even experienced physicians will benefit from inserting tubes to 20-21 cm in women and 22-23 cm in men, especially when high ambient noise precludes accurate auscultation (such as in emergency situations or helicopter transport). The highest sensitivity and specificity for ruling out endobronchial intubation, however, is achieved by combining tube depth, auscultation of the lungs, and observation of symmetrical chest movements., Trial Registration: NCT01232166.

Unlabelled: The UpsherScope, a rigid fiberoptic laryngoscope, may facilitate tracheal intubation. We performed a randomized, controlled trial of tracheal intubation using the UpsherScope and compared the success rate with that of direct laryngoscopy. Three hundred patients were randomly assigned to either fiberoptic oral intubation using the UpsherScope (Group US, n = 148) or to direct laryngoscopy (Group DL, n = 152). No significant differences in airway variables were observed between the groups. US intubation was successful in 129 of 148 patients (87%). A second or third attempt was required in 15% and 3%, respectively, of the patients successfully intubated with US. The remaining patients were intubated using DL (n = 17) or the flexible fiberoptic bronchoscope (n = 2). The success rate of DL was significantly higher (97%; P < 0.05), with a second or third attempt required in only seven patients. Time needed to perform successful intubation was 50 +/- 41 s for the US group compared with 23 +/- 13 s for the DL group (P < 0.05). We found no advantage of the UpsherScope over direct laryngoscopy during routine and difficult airway management. Time needed, number of attempts required to perform intubation, and incidence of failure were significantly longer and higher in group US., Implications: We studied tracheal intubation using the fiberoptic UpsherScope and compared the success rate with that of a control group of patients intubated using conventional laryngoscopy. No advantages of the new device were found. On the contrary, time needed, number of attempts required, and incidence of failure were even longer and higher.

Blind oral intubation using the Augustine Guide is helpful for intubating the trachea of patients presenting with difficult airways. This device has been modified by adding a fiberoptic scope with a built-in battery-powered light. We studied this Augustine Scope in 104 patients (Group AS) and compared the results with 96 patients managed by direct laryngoscopy (Group DL). No significant differences in Mallampati class, thyromental distance, laryngoscopic view, and patients height or weight were observed between the two groups. The Augustine Scope provided conditions for successful intubation in 102 of 104 patients (98%), compared with a 97% success rate in the group where DL was used. The three patients who failed DL were successfully intubated with AS. The mean +/- SD time needed to perform intubation was 19 +/- 10 s in Group AS and 21 +/- 13 s in Group DL (P = not significant). No traumatizing effects were observed. We conclude that the Augustine Scope is an effective and safe device for orotracheal intubation in routine and difficult airways.

Haemodynamic and hormonal responses to tracheal intubation can be profound and associated with serious cardiovascular and cerebral side effects. The Augustine Guide, a device enabling blind oral intubation, has been introduced recently. The aim of our study was to compare the haemodynamic and hormonal stress response of this method with direct laryngoscopy. Thirty five patients (ASA 1 and 2) were randomly assigned to undergo either direct laryngoscopy (n = 17), or blind oral intubation (n = 18). Haemodynamic responses and concentrations of adrenaline, noradrenaline and prolactin were determined prior to induction, before intubation and 5 min after intubation. The median duration of intubation was 22s for direct laryngoscopy vs 46s for blind oral intubation (p < 0.05). Between the groups, no significant differences were observed for heart rate, systolic or mean arterial blood pressure. Serum levels of adrenaline decreased slightly after induction and remained unaltered after intubation in both groups. Noradrenaline (1.01 vs 0.66 nmol.l-1) and prolactin (5.2 vs 2.9 nmol.l-1) levels were significantly higher after direct laryngoscopy compared to blind oral intubation. Although blind oral intubation took significantly longer to perform than direct laryngoscopy, hormonal stress response was less pronounced. Blind oral intubation should therefore not be withheld from patients with impaired cardiovascular reserve.

41 patients (ASA I-II) were intubated using a new device for blind oral intubation (Augustine Guide). A group of 33 consecutive patients (Mallampati I and II), was studied for routine intubation. Another group of eight patients (Mallampati III and IV) was selected to study the guide in difficult airway management. Intubation was successful in 31 of the 33 normal patients (two patients required a second attempt), and in seven of the eight patients in the difficult intubation group (three patients with two attempts). In the remaining three patients intubation had to be performed by direct laryngoscopy. One patient (Mallampati IV), was intubated by the Augustine guide after three unsuccessful attempts by direct laryngoscopy. The Augustine Guide proved to be helpful to intubating patients with an anterior larynx and receding mandible. However, blind oral intubation attempts required a median duration of 65 s (range 35-90 s). Patients with a low Mallampati score did not benefit from the new device.

The most appropriate technique for performing tracheal intubation in patients with cervical spine injury is debatable. Recently, a new device enabling blind oral intubation (Augustine Guide) with the patient's head and neck in the neutral position has been introduced. The aim of this study was to compare the extent of upper cervical spine movement during intubation with this device compared to direct laryngoscopy. Twelve patients (Mallampati I and II), without a cervical spine injury, were intubated using the Augustine Guide and afterwards by direct laryngoscopy. Both procedures were viewed radiographically. Extension in the upper cervical spine was determined at the point of the maximum excursion. By evaluating the joints occiput-C3 together as a functional unit, blind oral intubation caused 17 degrees (median) less extension compared to direct laryngoscopy (p < 0.01). The median differences observed for the individual joints were: 7 degrees in occiput-C1 (p < 0.05), 5 degrees in C1-2 (p < 0.01) and 6 degrees in C2-3 (p < 0.01) respectively. Since we assume that intubation-induced excursions of the injured spine are even higher, blind oral intubation might be a safe alternative for airway management in this special group of trauma victims.