Yoshiko Kida

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®, 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.

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

BackgroundDiffuse 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.MethodsWe 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.ResultsBaseline 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.ConclusionsPeak serum KL-6 level ≥700 U/ml may become a clinically useful marker of poor prognosis for diffuse alveolar hemorrhage.

Potential covariates that affect post-extubation breathing effort in children

Dear Editor, In a recent issue of Intensive Care Medicine, we read with interest the article by Khemani et al. [1], who investigated the breathing effort by using pressure rate product, a surrogate for breathing effort, under the following four conditions: (1) pressure support (PS), (2) continuous positive airway pressure (CPAP), and spontaneous breathing (3) 5 min and (4) 60 min after extubation. They demonstrated that the use of PS in extubation readiness tests for intubated children underestimated post-extubation breathing effort. We appreciate this research for providing useful information for the search for more-appropriate ventilator modes for extubation readiness tests in children. However, several factors that potentially affect the current results should be discussed. First, the ventilator settings for the extubation readiness tests were still controversial. In this study, extubation readiness tests were performed with the setting of PS 10/positive end-expiratory pressure (PEEP) 5 cmH2O, which appeared to be too high for PS on the basis of a previous suggestion to adjust the PS level according to the endotracheal tube size [2]. In addition, PS measurements were made within 20 min of extubation, although the normal duration of extubation readiness tests for adult is 30–120 min [3]. The authors shows the correlation between peak inspiratory flow and endotracheal tube resistance using various sizes of endotracheal tube in a bench model [1]. On the basis of these results, the authors concluded that endotracheal tube resistance in intubated children was not associated with the flow rates, regardless of tube size. However, these experiments were performed when the CPAP was 5 cmH2O, and the dynamics when the PS was 10 cmH2O are unclear. Additional data from extubation readiness tests with an adjusted setting for PS would be helpful for better understanding the effect of PS. Second, the effects of uncuffed and cuffed endotracheal tubes need to be considered. Of the patients included in this study, 60 % used an uncuffed endotracheal tube, while the rest of the patients used a cuffed tube. The use of cuffed tubes is associated with a reliable sealing of airway and avoids excessive air leak compared with uncuffed tubes [4]. This could have affected the breathing effort before and after extubation. A subanalysis according to tube types would provide more information regarding adequate ventilator support. Third, potential covariates that affect post-extubation breathing effort should be taken into account. Peñuelas et al. demonstrated that the duration of mechanical ventilation, complication with chronic lung diseases, presence of pneumonia, and use of high PEEP were associated with prolonged weaning from mechanical ventilation in adults [5]. Sedative dose or fluid balance could also affect post-extubation breathing effort. Information on these potential covariates would be helpful.

A Case of Severe Puffer Fish Poisoning: Serum Tetrodotoxin Concentration Measurements for 4 Days after Ingestion

Yasumasa Iwasaki1, Akira Namera2, Hiroshi Giga1, Yoshiko Kida1, Kohei Ota1, Kazunobu Une1, Tadatsugu Otani1, Shinichiro Ohshimo1, Nobuyuki Hirohashi1, Koichi Tanigawa1 1Department of Emergency and Critical Care Medicine, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan 2Department of Forensic Medicine, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan *Corresponding author: Yasumasa Iwasaki, Department of Emergency and Critical Care Medicine, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan, Tel: 81-90-8242-4859; E-mail: yiwasaki@hiroshima-u.ac.jp

Exploring Potential Cofactors Affecting Coagulation and Inflammation Activity During Extracorporeal Membrane Oxygenation

To the Editor: In a recent issue of Critical Care Medicine, we read with interest the article by Malfertheiner et al (1), who compared the impact of three different extracorporeal membrane oxygenation (ECMO) systems on blood hemostasis in adult patients during venovenous ECMO therapy. In that prospective randomized single-center pilot study, they recruited 54 adult patients and investigated them for the first 5 days after starting venovenous ECMO. Although blood markers indicating coagulation, hemolysis, and inflammatory activity were affected by venovenous ECMO, no differences were observed among the three ECMO systems. We appreciate this research for providing useful information for considering coagulation, hemolysis, and inflammation during ECMO therapy. Several factors, however, potentially affecting the results of the above study should be discussed. First, the baseline characteristics potentially affecting coagulation, hemolysis, and inflammation were not well evaluated. One of the most significant cofactors could be infection. Inflammatory cytokines activate coagulation cascades by excess production of tissue factors from monocytes and macrophages, which could result in disseminated intravascular coagulation (2). A previous study has shown an association between sepsis and coagulation abnormalities (3). A significant correlation has been demonstrated between thrombomodulin, plasminogen activator inhibitor, and tumor necrosis factor in sepsis, suggesting potential interaction between infection, coagulation, and inflammation (4). Comparison of the prevalence of infection and causative microorganisms or trends in inflammatory biomarkers (e.g., procalcitonin) among the groups would be of interest. Second, the correlation between the coagulation, hemolysis, and inflammation variables and clinical manifestation is unclear. Abnormalities in these variables do not always correlate with the risk of bleeding or thrombosis, because several cofactors including liver function, capillary fragility, or medication can also affect these risks. The conclusion that all ECMO devices tested are suitable for long-term use regarding bleeding and thrombosis is likely to have been overstated. Third, limiting the study period to the first 5 days after starting ECMO seems too short to evaluate the safety and efficacy main reasons for my position: the first is that patients do not always fall into a given category–in fact, this is a rare event. For example, a polytrauma patient may have severe brain injury as well as damage to other organs, and a patient with severe cirrhosis may develop a serious intracerebral bleed. It has been shown that patients admitted to the incorrect or “nonideal” subspecialty ICU have worse outcomes (3, 4), but so often these patients have multiple problems, making it very difficult to identify which subspecialty ICU is, in fact, most appropriate. The second reason is that many, if not most, of the problems we deal with in everyday intensive care practice (sepsis, electrolyte disturbances, nutritional support, respiratory management, etc.) are identical in so-called “neuro” patients (a term that I dislike as it labels a patient by their diagnosis, thus removing their individuality, and restricts their condition to a neurologic problem) and in other patients. I believe that the management of severe intracranial hypertension should be as much a part of the work of the intensivist as is the management of shock, acute respiratory distress syndrome, or cardiac arrest. I will go one step further: I do not understand how in some hospitals medical and surgical ICU patients are still treated in separate units, when a surgical ICU patient is hardly more than a medical ICU patient with a scar. Let us break these walls down—they just do not make sense. Fortunately, many authorities in Belgium, as in other countries, are fully supportive of the concept of multidisciplinary ICUs and discourage these often historic separations, preferring rather to merge the various units into a single department. In our mixed Department of Intensive Care at the University of Brussels, one can find, for example, a patient with subarachnoid hemorrhage next to one with decompensated liver cirrhosis (with encephalopathy), followed by a patient with severe pneumonia (with a history of cerebrovascular accident) and one with polytrauma including severe brain injury (all in separate rooms, I can reassure the reader), without mentioning all the other concomitant problems these patients may have. Intensive care medicine is a specialty in its own right. Of course, consultations with physicians from other disciplines are welcome, but the intensivist must remain in charge. Many intensivists will have a special field of interest and may well have a favorite topic(s) of research, but all should be trained to be fully competent to manage all the conditions that will be encountered on the ICU. ICU patients are increasingly complex, combining multiple problems involving multiple organs. Our patients deserve and expect to be treated by fully trained specialists in intensive care. And, as intensivists, we must treat the individual as a whole, not the disease or any specific organ. Our patients are counting on this. Dr. Vincent has disclosed that he does not have any potential conflicts of interest.