Influence of clinical experience of the Macintosh laryngoscope on performance with the Pentax-AWS Airway Scope(®), a rigid video-laryngoscope, by paramedics in Japan.

PURPOSE: We sought to establish the clinical utility of the Pentax-AWS Airway Scope(®) (AWS) when used by paramedics to intubate the trachea, and to evaluate whether their performance was influenced by previous clinical experience with the Macintosh laryngoscope (ML). METHODS: Twenty paramedics attempted tracheal intubation using the AWS in five patients each in the operating room. We recorded the success rate, the number of intubation attempts, and the time for intubation and adverse events, and compared these based on the paramedics' previous clinical experience with the ML. Ten paramedics had no prior clinical experience of the ML (group A) and 10 had used it on more than 30 occasions (group B). RESULTS: The intubation success rate was 99 % (99/100). Notably, 96 % (47/49) of intubations were achieved on the first attempt by the inexperienced paramedics in group A, compared with 64 % (32/50) by the experienced paramedics in group B (p = 0.0001). The time to intubation (mean ± SD) was significantly shorter in group A than in group B (37 ± 24 vs. 48 ± 21 s, p = 0.002). There were marked variations in the times taken to intubate, but no apparent improvement as the intubators gained experience between their first and fifth cases. No complications were encountered in either group. CONCLUSION: We found that paramedics could achieve a high tracheal intubation success rate using the AWS independent of previous airway management experience. Better intubation performance with the AWS was observed in paramedics without clinical experience with the ML.

KL-6, a Human MUC1 Mucin, as a prognostic marker for diffuse alveolar hemorrhage syndrome.

BACKGROUND: Diffuse alveolar hemorrhage syndrome is a life threatening condition with diverse etiologies. Sensitive prognostic markers for diffuse alveolar hemorrhage have not been well investigated. Serum KL-6 is a biomarker for various interstitial lung disease associated with disease activity and prognosis. The purpose of the present study was to evaluate the clinical utility of serum KL-6 level as a prognostic marker for diffuse alveolar hemorrhage. METHODS: We retrospectively collected 41 consecutive patients clinically diagnosed as having diffuse alveolar hemorrhage who were admitted to the Intensive Care Unit of Hiroshima University Hospital between 2004 and 2011. Correlation between prognosis and age, sex, laboratory findings including serum KL-6, radiological findings, ventilatory modes or therapeutic regimens were evaluated. RESULTS: Baseline and peak serum KL-6 levels were significantly higher in non-survivors compared with survivors. An increase in KL-6 levels during the initial week was associated with a subsequent deterioration of the oxygenation index. Higher baseline KL-6 levels and higher peak KL-6 levels were strongly correlated with death. With a cut-off level of 700 U/mL for peak KL-6, the sensitivity, specificity and accuracy for non-survival were 75%, 85% and 78%, respectively. In the multivariate analysis, only the peak KL-6 level ≥ 700 U/ml was an independent poor prognostic factor for diffuse alveolar hemorrhage. CONCLUSIONS: Peak serum KL-6 level ≥ 700 U/ml may become a clinically useful marker of poor prognosis for diffuse alveolar hemorrhage.

Tracheal intubation of a difficult airway using Airway Scope, Airtraq, and Macintosh laryngoscope: a comparative manikin study of inexperienced personnel.

BACKGROUND: The Airway Scope (AWS) (Pentax-AWS, Hoya Corp., Tokyo, Japan) and the Airtraq (ATQ) (Prodol, Vizcaya, Spain) have similarities in the novel structures of their blades. In this study, we evaluated the ease of use of the AWS and ATQ compared with the Macintosh laryngoscope (ML) by inexperienced personnel in a simulated manikin difficult airway. METHODS: Twenty-four fifth-year medical students with no previous experience in tracheal intubation participated in this study. We used an advanced patient simulator (SimMan(R), Laerdal Medical, Stavanger, Norway) to simulate difficult airway scenarios including cervical spine rigidity, limited mouth opening, and pharyngeal obstruction. The sequences in selecting devices and scenarios were randomized. Success rates for tracheal intubation, and the time required for visualization of the glottis, tracheal intubation, and inflation of the lungs, and the number of optimization maneuvers and dental click sounds were analyzed. The 3 different intubation devices were tested in 4 different scenarios by 24 students. RESULTS: Both the AWS and ATQ had very high success rates of tracheal intubation compared with the ML (AWS 100%*; ATQ 98%*; and ML 89%; *P < 0.05 AWS, ATQ versus ML). The time to intubation with the AWS was significantly shorter than with the ATQ and ML (AWS 11 +/- 6 seconds; ATQ 16 +/- 12 seconds; and ML 16 +/- 11 seconds; *P < 0.05 AWS versus ATQ, ML). The number of optimization maneuvers with the AWS was significantly lower than with the ATQ and ML. There were significantly more audible dental click sounds with the ML than with the AWS and ATQ. CONCLUSION: Both the AWS and ATQ may be suitable devices for difficult intubation by inexperienced personnel in this manikin simulated scenario. Further studies in a clinical setting are necessary to confirm these findings.

Practical use of airway pressure release ventilation for severe ARDS--a preliminary report in comparison with a conventional ventilatory support.

Airway pressure release ventilation (APRV) is a ventilatory mode that allows unsupported spontaneous breathing at any phase of the ventilatory cycle with high mean airway pressures. We hypothesized that use of APRV might produce potential beneficial effects on oxygenation, reducing mortality in patients with severe acute respiratory distress syndrome (ARDS) in comparison with synchronized intermittent mandatory ventilation (SIMV) as a conventional mode of ventilation. We retrospectively reviewed data of 58 patients with severe ARDS (the ratios of partial arterial oxygen tension to fraction of inspired oxygen, PaO2/F(I)O2 ratio <150). The patients' data were divided into two groups: SIMV-group and APRV-group. Patients' backgrounds, oxygenation on day 0, 1, 3, 5 and 7 following initiation of each mode, vasopressor dependence, duration of ventilation, duration of ICU stay, and mortality in ICU were analyzed. PaO2/F(I)O2 ratios were statistically higher in the APRV-group (APRV vs. SIMV on day 1, 3, 5, 7: 201.6 +/- 76 vs.150 +/- 59.1, 256.7 +/- 71.5 vs.182.1 +/- 65.4, 268.8 +/- 73.3 vs. 204.6 +/- 72.8, and 263 +/- 74.5 vs. 204.1 +/- 67.1, respectively, p<0.05). Vasopressors were less used (p=0.018), and mortality in ICU tended to be lower in the APRV group (31%) than in the SIMV group (59%) (p=0.050). Use of APRV in patients with severe ARDS appears to be associated with improvements in oxygenation, and a trend toward lower mortality in ICU. No significant adverse effects were observed. Prospective controlled studies are required to confirm the benefits of this ventilatory mode in comparison with conventional methods for severe ARDS.

Airway Scope for emergency intubations: usefulness of a new video-laryngoscope.

The Airway Scope (AWS-S100, Pentax, Tokyo, Japan) is a new video-laryngoscope, which has a specially designed blade and a portable, battery-powered, 2.4-inch built-in liquid crystal device (LCD) full-color video screen at the top of the handle. In this study, we tested the usefulness of the AWS for tracheal intubation in acute, urgent situations. Patients admitted to the Advanced Emergency and Critical Care Center at Hiroshima University Hospital and who required orotracheal intubations were prospectively enrolled. Tracheal intubations were performed using the AWS by residents (the novice group) or staff physicians (the experienced group), who received a brief instruction in the AWS. We enrolled 38 patients (23 males, 15 females; age, 60 +/- 19 years). Intubations were attempted by 22 intubators (11 residents and 11 experienced personnel). The durations from inserting the blade via the oral cavity until observing the glottis (T1), inserting the tube into the trachea (T2), and confirming the chest rise (T3) were 22 +/- 15, 34 +/- 21 and 49 +/- 27 sec, respectively. When the results were classified into t experienced and novice groups, T1, T2 and T3 were 17 +/- 10 vs. 26 +/- 17, 32 +/- 23 vs. 36 +/- 20, and 45 +/- 25 vs. 53 +/- 27 sec, respectively (the experienced vs. the novice group, n.s.). These results suggested that the AWS may be a suitable device particularly for less experienced personnel, such as novice Advanced Life Support providers.