Eric Chou M.D.

Wang, C.H., Wu, C.Y., Wu, M.C., Chang, W.T., Huang, C.H., Tsai, M.S., Lu, T.C., Chou, E., Hsieh, Y.L. and Chen, W.J. (2021). “A retrospective study on the therapeutic effects of sodium bicarbonate for adult in-hospital cardiac arrest.” Sci Rep 11(1): 12380.

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To investigate whether the effects of sodium bicarbonate (SB) during cardiopulmonary resuscitation (CPR) would be influenced by blood pH and administration timing. Adult patients experiencing in-hospital cardiac arrest (IHCA) from 2006 to 2015 were retrospectively screened. Early intra-arrest blood gas data were obtained within 10 min of CPR. Multivariable logistic regression analysis and generalised additive models were used for effect estimation and data exploration, respectively. A total of 1060 patients were included. Only 59 patients demonstrated favourable neurological status at hospital discharge. Blood pH ≤ 7.18 was inversely associated with favourable neurological outcome (odds ratio [OR], 0.24; 95% confidence interval [CI], 0.11-0.52; p value < 0.001) while SB use was not. In the interaction analysis for favourable neurological outcome, significant interactions were noted between SB use and time to SB (SB use × time to SB ≥ 20 min; OR 6.16; 95% CI 1.42-26.75; p value = 0.02). In the interaction analysis for survival to hospital discharge, significant interactions were noted between SB use and blood pH (Non-SB use × blood pH > 7.18; OR 1.56; 95% CI 1.01-2.41; p value = 0.05). SB should not be empirically administered for patients with IHCA since its effects may be influenced by blood pH and administration timing.

Wang, C.H., Wu, M.C., Wu, C.Y., Huang, C.H., Tsai, M.S., Lu, T.C., Chou, E., Wu, Y.W., Chang, W.T. and Chen, W.J. (2021). “Blood gas phenotyping and tracheal intubation timing in adult in-hospital cardiac arrest: a retrospective cohort study.” Sci Rep 11(1): 10480.

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To investigate whether the optimal time to tracheal intubation (TTI) during cardiopulmonary resuscitation would differ by different blood gas phenotypes. Adult patients experiencing in-hospital cardiac arrest (IHCA) from 2006 to 2015 were retrospectively screened. Early intra-arrest blood gas analysis, performed within 10 min of resuscitation, was used to define different phenotypes. In total, 567 patients were included. Non-severe acidosis (pH≧7.15) was associated with favourable neurological outcome (odds ratio [OR]: 4.60, 95% confidence interval [CI] 1.63-12.95; p value = 0.004) and survival (OR: 3.25, 95% CI 1.72-6.15; p value < 0.001) in the multivariable logistic regression analyses. In the interaction analysis, normal blood gas phenotype (pH: 7.35-7.45, PCO(2): 35-45 mm Hg, HCO(3)(-) level: 22-26 mmol/L) × TTI ≦ 6.3 min (OR: 20.40, 95% CI 2.53-164.75; p value = 0.005) and non-severe acidosis × TTI ≦ 6.3 min (OR: 3.35, 95% CI 1.00-11.23; p value = 0.05) were associated with neurological recovery while metabolic acidosis × TTI ≦ 5.7 min (OR: 3.63, 95% CI 1.36-9.67; p value = 0.01) and hypercapnic acidosis × TTI ≦ 10.4 min (OR: 2.27, 95% CI 1.20-4.28; p value = 0.01) were associated with survival. Intra-arrest blood gas analysis may help guide TTI during for patients with IHCA.

Hsieh, Y.L., Wu, M.C., Wolfshohl, J., d’Etienne, J., Huang, C.H., Lu, T.C., Huang, E.P., Chou, E.H., Wang, C.H. and Chen, W.J. (2021). “Intraosseous versus intravenous vascular access during cardiopulmonary resuscitation for out-of-hospital cardiac arrest: a systematic review and meta-analysis of observational studies.” Scand J Trauma Resusc Emerg Med 29(1): 44.

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INTRODUCTION: This study is aimed to investigate the association of intraosseous (IO) versus intravenous (IV) route during cardiopulmonary resuscitation (CPR) with outcomes after out-of-hospital cardiac arrest (OHCA). METHODS: We systematically searched PubMed, Embase, Cochrane Library and Web of Science from the database inception through April 2020. Our search strings included designed keywords for two concepts, i.e. vascular access and cardiac arrest. There were no limitations implemented in the search strategy. We selected studies comparing IO versus IV access in neurological or survival outcomes after OHCA. Favourable neurological outcome at hospital discharge was pre-specified as the primary outcome. We pooled the effect estimates in random-effects models and quantified the heterogeneity by the I(2) statistics. Time to intervention, defined as time interval from call for emergency medical services to establishing vascular access or administering medications, was hypothesized to be a potential outcome moderator and examined in subgroup analysis with meta-regression. RESULTS: Nine retrospective observational studies involving 111,746 adult OHCA patients were included. Most studies were rated as high quality according to Newcastle-Ottawa Scale. The pooled results demonstrated no significant association between types of vascular access and the primary outcome (odds ratio [OR], 0.60; 95% confidence interval [CI], 0.27-1.33; I(2), 95%). In subgroup analysis, time to intervention was noted to be positively associated with the pooled OR of achieving the primary outcome (OR: 3.95, 95% CI, 1.42-11.02, p: 0.02). That is, when the studies not accounting for the variable of “time to intervention” in the statistical analysis were pooled together, the meta-analytic results between IO access and favourable outcomes would be biased toward inverse association. No obvious publication bias was detected by the funnel plot. CONCLUSIONS: The meta-analysis revealed no significant association between types of vascular access and neurological outcomes at hospital discharge among OHCA patients. Time to intervention was identified to be an important outcome moderator in this meta-analysis of observation studies. These results call for the need for future clinical trials to investigate the unbiased effect of IO use on OHCA CPR.

Pei-Chuan Huang, E., C. M. Fu, W. T. Chang, C. H. Huang, M. S. Tsai, E. Chou, J. Wolfshohl, C. H. Wang, Y. W. Wu and W. J. Chen (2020). “Associations of thoracic cage size and configuration with outcomes of adult in-hospital cardiac arrest: A retrospective cohort study.” J Formos Med Assoc Jun 11;S0929-6646(20)30231-X. [Epub ahead of print.].

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BACKGROUND: To analyse the association of thoracic cage size and configuration with outcomes following in-hospital cardiac arrest (IHCA). METHODS: A single-centred retrospective study was conducted. Adult patients experiencing IHCA during 2006-2015 were screened. By analysing computed tomography images, we measured thoracic anterior-posterior and transverse diameters, circumference, and both anterior and posterior subcutaneous adipose tissue (SAT) depths at the level of the internipple line (INL). We also recorded the anatomical structure located immediately posterior to the sternum at the INL. RESULTS: A total of 649 patients were included. The median thoracic circumference was 88.6 cm. The median anterior and posterior thoracic SAT depths were 0.9 and 1.5 cm, respectively. The ascending aorta was found to be the most common retrosternal structure (57.6%) at the INL. Multivariate logistic regression analyses indicated that anterior thoracic SAT depth of 0.8-1.6 cm (odds ratio [OR]: 2.98, 95% confidence interval [CI]: 1.40-6.35; p-value = 0.005) and thoracic circumference of 83.9-95.0 cm (OR: 2.48, 95% CI: 1.16-5.29; p-value = 0.02) were positively associated with a favourable neurological outcome while left ventricular outflow track or aortic root beneath sternum at the level of INL was inversely associated with a favourable neurological outcome (OR: 0.37, 95% CI: 0.15-0.91; p-value = 0.03). CONCLUSION: Thoracic circumference and anatomic configuration might be associated with IHCA outcomes. This proof-of-concept study suggested that a one-size-fits-all resuscitation technique might not be suitable. Further investigation is needed to investigate the method of providing personalized resuscitation tailored to patient needs.

Wang, C. H., A. F. Lee, W. T. Chang, C. H. Huang, M. S. Tsai, E. Chou, C. C. Lee, S. C. Chen and W. J. Chen (2020). “Comparing Effectiveness of Initial Airway Interventions for Out-of-Hospital Cardiac Arrest: A Systematic Review and Network Meta-analysis of Clinical Controlled Trials.” Ann Emerg Med 75(5): 627-636.

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STUDY OBJECTIVE: We compare effectiveness of different airway interventions during cardiopulmonary resuscitation for patients with out-of-hospital cardiac arrest. METHODS: We systematically searched the PubMed and EMBASE databases from their inception through August 2018 and selected randomized controlled trials or quasi randomized controlled trials comparing intubation, supraglottic airways, or bag-valve-mask ventilation for treating adult out-of-hospital cardiac arrest patients. We performed a network meta-analysis along with sensitivity analyses to investigate the influence of high intubation success rate on meta-analytic results. RESULTS: A total of 8 randomized controlled trials and 3 quasi randomized controlled trials were included in the network meta-analysis: 7,361 patients received intubation, 7,475 received supraglottic airway, and 1,201 received bag-valve-mask ventilation. The network meta-analysis indicated no differences among these interventions for survival or neurologic outcomes at hospital discharge. Rather, network meta-analysis suggested that supraglottic airway improved the rate of return of spontaneous circulation compared with intubation (odds ratio 1.11; 95% confidence interval 1.03 to 1.20) or bag-valve-mask ventilation (odds ratio 1.35; 95% confidence interval 1.11 to 1.63). Furthermore, intubation improved the rate of return of spontaneous circulation compared with bag-valve-mask ventilation (odds ratio 1.21; 95% confidence interval 1.01 to 1.44). The sensitivity analyses revealed that the meta-analytic results were sensitive to the intubation success rates across different out-of-hospital care systems. CONCLUSION: Although there were no differences in long-term survival or neurologic outcome among these airway interventions, these system-based comparisons demonstrated that supraglottic airway was better than intubation or bag-valve-mask ventilation and intubation was better than bag-valve-mask ventilation in improving return of spontaneous circulation. The intubation success rate greatly influenced the meta-analytic results, and therefore these comparison results should be interpreted with these system differences in mind.