YeonHo You

Optimum location for chest compressions during two-rescuer infant cardiopulmonary resuscitation

OBJECTIVES The study aims to evaluate the optimal chest compression site in two-rescuer infant cardiopulmonary resuscitation (CPR). METHODS Charts and multidirectional computed tomography images of infants who presented to one of four hospitals from March 2004 to March 2009 were reviewed retrospectively. The length of the sternum (S(total)), the length and width (L, W) of adult thumbs after two thumbs were placed side-by-side were measured. The study included the structures located underneath the lower third of S(total) (S(total/3)), the lower half of S(total) (S(total/2)), the sternum at the inter-nipple line (S(n)), the point of maximal anterior-posterior heart diameter (S(m)), the lower margin of L and the lateral margin of W from S(total/3), S(total/2), S(n) and S(m). RESULTS Of the 75 infants enrolled, the ratio of the length from the xiphoid process to S(m) from S(total) was 0.24+/-0.19. In the population studied, 43.1% had aortic roots in S(total/2), 44.0% had left ventricular outflow tracts in S(total/3), 46.7% had left ventricular outflow tracts at S(n) and 100.0% had left ventricles at S(m). All the infants had livers in the lower margin of L from S(m) and all of them had hearts in the left lateral margin of half of W from S(m). A total of 42.7% had lungs in the right lateral margin of half of W from S(m). CONCLUSION The left ventricle was located in the lower quarter of the sternum, lower than S(total/3). However, more studies are needed to validate the efficiency and safety of compressing the lower quarter of the sternum in two-rescuer infant CPR.

Association of blood glucose variability with outcomes in comatose cardiac arrest survivors treated with therapeutic hypothermia.

PURPOSE A recent study showed that increased blood glucose variability was an independent predictor of mortality in cardiac arrest survivors treated with therapeutic hypothermia (TH). We hypothesized that the association of blood glucose variability with outcomes would differ depending on the TH phase, as body temperature affects glucose homeostasis. METHODS A retrospective cohort of 147 consecutive cardiac arrest patients treated with TH was analyzed. Mean absolute glucose change (MAGC) was calculated using blood glucose values during the entire TH period and during each TH phase (induction, from the TH initiation to the achievement of the target temperature; maintenance, 24 hours from the end of induction; and rewarming, from the end of the maintenance to the achievement of 36.5°C). The primary and secondary outcomes were mortality and neurological outcome at 30 days. Multivariate regression analyses were performed with variables with a significance level <0.1 on univariate analyses. RESULTS The hypoglycemia rate increased significantly during the rewarming phase compared with the maintenance phase (P = .003). The MAGC during the TH maintenance phase was an independent predictor of mortality (OR = 1.056, 95% CI 1.008-1.107, P = .023) and unfavorable neurologic outcome (OR = 1.202, 95% CI 1.043-1.384, P = .038), while the MAGC during the rewarming phase and the entire TH period were not. CONCLUSION The increased MAGC during the TH maintenance phase was associated with mortality and unfavorable neurologic outcome. However, this study cannot prove a causal association due to the retrospective design. In addition, we showed that the hypoglycemia rate increased significantly during the rewarming phase.

Comparison of overlapping (OP) and adjacent thumb positions (AP) for cardiac compressions using the encircling method in infants

Objectives The aim of this manikin study was to compare the efficiency between overlapping (OP) and adjacent thumb positions (AP) for cardiac compressions using the encircling method in infants. Methods The study conducted from December 2010 to August 2011 involved 48 volunteers who were students in the emergency medical technician course. The authors let volunteers practice OP and AP as a crossover design. The authors monitored the simulated mean arterial pressure (MAP) generated during a 5-min chest compression. The fatigue level of the volunteers after the chest compression was evaluated with the Likert scale. Results There were no significant differences in MAP between the dominant hand and the non-dominant hand as the lower thumb of OP. Significant differences were observed in simulated systolic blood pressure, MAP and simulated pulse pressure between OP and AP at 1, 2, 3, 4 and 5 min. There were no significant differences among the changes in heart rate, respiratory rate and end-tidal CO2 during a 5-min chest compression by OP and AP. The Likert scale scores (1 no fatigue to 5= extreme fatigue) during the 5-min chest compressions were higher in AP than in OP at 2, 3 and 5 min. Conclusion Higher intrathoracic pressures were achieved by OP in this study. However, further studies are needed to validate these effects of overlapping thumbs technique in infant cardiopulmonary resuscitation, not manikin.

Effect of intravenous fat emulsion therapy on glyphosate-surfactant–induced cardiovascular collapse

Intravenous fat emulsion (IFE) therapy is an adjunct therapy administered to hemodynamically compromised patients with glyphosate-surfactant intoxication when they respond poorly to conventional therapies such as fluid resuscitation or vasopressors [1,2]. However, the use of IFE as an adjunct therapy in collapsed patients with glyphosate intoxication has not been reported previously. Here, we describe the case of a patient with glyphosate-surfactant–induced cardiovascular collapse who responded to IFE.

Performance of an automated external defibrillator in a moving ambulance vehicle

AIM OF THE STUDY The available data suggest that automated external defibrillators (AED) can be safely used in vibration-like moving conditions such as rigid inflatable boats and aircraft environments. However, little literature exists examining their performance in a moving ambulance. The present study was undertaken to determine whether an AED is able to analyse the heart rhythm correctly during ambulance transport. METHODS An ambulance was driven on paved (20-100 km/h) and unpaved (10 km/h) roads. The performance of two AED devices (CU ER 2, CU Medical Systems Inc., Korea, and Heartstart MRx, Phillips, USA) was determined in a moving ambulance using manikins. Vibration intensity was measured simultaneously with a digital vibrometer. AED performance was then evaluated again on manikins and on a swine model under simulated vibration intensities (0.5-5m/s(2)) measured by the vibrometer in the previous phase of the investigation. RESULTS The vibration intensity increased with increasing speeds on paved roads (1.98+/-0.44 m/s(2) at 100 km/h). While driving on unpaved roads, it increased to 6.40+/-1.06 m/s(2). Both AED algorithms analysed the heart rhythm correctly under resting state. When tested on pigs, both algorithms showed substantially degraded performances, even at low vibration intensities of 0.5-1m/s(2), which corresponded to vibration intensities while driving on paved roads at 20-60 km/h. This study also showed that electrocardiograms generated on manikins were more resistant to motion artifacts than were the pig electrocardiograms. CONCLUSION Ambulance personnel should consider the possibility of misinterpretation by an AED when this device is used while transporting a patient.

Vasopressor requirement during targeted temperature management for out-of-hospital cardiac arrest caused by acute myocardial infarction without cardiogenic shock

Objective We investigated whether patients with out-of-hospital cardiac arrest (OHCA) due to an acute myocardial infarction without cardiogenic shock required higher doses of vasopressors with low targeted temperature management (TTM) after return of spontaneous circulation. Methods We included consecutive comatose patients resuscitated from OHCA between January 2011 and December 2013. Patients with return of spontaneous circulation, regional wall motion abnormality on echocardiography, and coronary artery stenosis of ≥70% on percutaneous coronary artery angiography were enrolled. These patients received 36°C TTM or 33°C TTM following approval of TTM by patients’ next-of-kin (36°C and 33°C TTM groups, respectively). The cumulative vasopressor index was compared between groups. Results During induction phase, dose of vasopressors did not differ between groups. In the maintenance phase, the norepinephrine dose was 0.37±0.57 and 0.26±0.91 µg·kg-1·min-1 in the 33°C and 36°C TTM groups, respectively (P<0.01). During the rewarming phase, the norepinephrine and dopamine doses were 0.49±0.60 and 9.67±9.60 mcg·kg-1·min-1 in the 33°C TTM group and 0.14±0.46 and 3.13±7.19 mcg·kg-1·min-1 in the 36°C TTM group, respectively (P<0.01). The median cumulative vasopressor index was 8 (interquartile range, 3 to 8) and 4 (interquartile range, 0 to 8) in the 33°C and 36°C TTM groups, respectively (P=0.03). Conclusion In this study, patients with OHCA due to acute myocardial infarction without cardiogenic shock had an elevated vasopressor requirement with 33°C TTM compared to 36°C TTM during the maintenance and rewarming phases.

Study on the timing of severe blood-brain barrier disruption using cerebrospinal fluid-serum albumin quotient in post cardiac arrest patients treated with targeted temperature management

AIM We aimed to evaluate the onset of severe blood-brain barrier (BBB) disruption using cerebrospinal fluid/serum albumin quotient (Qa) in cardiac arrest patients treated with target temperature management (TTM). METHODS This was a prospective single-centre observational cohort study from October 2017 to September 2018 with the primary endpoint being the onset of severe BBB disruption, determined based on Qa in cardiac arrest patients treated with TTM. Enrolled patients were grouped according to neurologically good and poor outcomes using the cerebral performance category (CPC) at 3 months after return of spontaneous circulation (ROSC). Severe BBB disruption was evaluated using Qa measured immediately (Qa0) and at 24 h (Qa24), 48 h (Qa48), 72 h (Qa72) after ROSC. RESULTS Of 21 patients enrolled, poor outcome group had 10 patients. Qa0 was 0.019 (0.008∼0.024) in the poor outcome group and 0.006 (0.003∼0.008) in the good outcome group (p = 0.09). Qa24 was 0.045 (0.025∼0.115) in the poor outcome group and 0.006 (0.003∼0.006) in the good outcome group (p = 0.03). Qa48 was 0.055 (0.023∼0.276) in the poor outcome group and 0.006 (0.006∼0.009) in the good outcome group (p = 0.02). Qa72 was 0.047 (0.026∼0.431) in the poor outcome group and 0.007 (0.005∼0.011) in the good outcome group (p = 0.02). CONCLUSION Qa was significantly higher in the poor outcome group at 24 h, 48 h, and 72 h. Severe BBB disruption indicated by Qa ≥ 0.02 in poor outcome group treated with TTM occurred within the first 24 h after ROSC.

Comparison of right and left ventricular enhancement times using a microbubble contrast agent between proximal humeral intraosseous access and brachial intravenous access during cardiopulmonary resuscitation in adults

AIM The present study aimed to compare the ventricular enhancement time between humeral intraosseous access (HIO) and brachial intravenous access (BIV) during cardiopulmonary resuscitation (CPR) in adult humans. To our knowledge, this is the first such study during CPR in adult humans. METHODS This prospective single-centre observational cohort study assessed the medical records of patients who underwent CPR between January 2018 and March 2018. The primary endpoints were the left and right ventricular enhancement (LVE and RVE, respectively) times after administration of a microbubble contrast agent via HIO or BIV. Continuous variables are reported as means and standard deviations depending on normal distribution, while categorical variables are reported as frequencies and percentages. The paired t-test and analysis of variance were used to compare HIO and BIV. Differences were considered significant at a P-value <0.05. RESULTS The study included 10 patients. The HIO time (15.60 ± 6.45 s) was significantly lower than the BIV time (20.80 ± 7.05 s; P = 0.009). The RVE time was significantly lower with HIO (5.60 ± 1.71 s) than with BIV (15.40 ± 3.24 s; P < 0.001). Additionally, the LVE time was significantly lower with HIO (120.20 ± 4.18 s) than with BIV (132.00 ± 3.09 s; P < 0.001). CONCLUSION Our results indicated that the arrival times of a drug at the right and left ventricles are significantly lower with HIO than with BIV in an adult cardiac arrest model.

Relationship between time related serum albumin concentration, optic nerve sheath diameter, cerebrospinal fluid pressure, and neurological prognosis in cardiac arrest survivors

AIM The optimal time to measure serum albumin concentration (SAC) to predict prognosis in cardiac arrest (CA) survivors has not been elucidated. We aimed to compare the relationships between time-related SAC, optic nerve sheath diameter (ONSD), intracranial pressure (ICP), and neurological prognosis in CA survivors. METHODS We undertook a retrospective study examining CA patients treated with target temperature management (TTM). ICP was measured using cerebrospinal fluid (CSF) pressure and ONSD was obtained before TTM. SAC was measured repeatedly at 4-6 h intervals from the hospital arrival time. We analysed CSF pressure, ONSD, and minimum SAC (MSAC) separately, or in combination, to predict poor neurological outcome. RESULTS Of 83 patients enrolled, the good outcome group comprised 25 (34%) patients. MSAC at 24 h (MSAC24) had a higher area under the receiver operating characteristic curve (AUC) (0.687; 95% confidence interval (CI), 0.668-0.926) than other time points. CSF pressure showed a higher AUC (0.973; 95% CI, 0.911-0.996) than MSAC24 and ONSD (0.677; 95% CI, 0.565-0.776). In contrast to using MSAC24 and ONSD separately, the combination of both modalities resulted in a better AUC, thus improving the prediction of the neurological outcome (0.734; 95% CI, 0.626-0.825) and ICP (0.758; 95% CI, 0.651-0.845) after return of spontaneous circulation (ROSC) from CA. CONCLUSION A higher ICP was strongly associated with and seemed predictive of poor outcome. Furthermore, the MSAC24/ONSD combination may be a useful predictor of high ICP and poor neurological outcome. Prospective studies should be conducted to confirm these results.