Supranormal arterial oxygen tension only during the first six hours after cardiac arrest is associated with unfavourable outcomes.

BACKGROUND: Multiple studies have investigated the association between hyperoxaemia following cardiac arrest (CA) and unfavourable outcomes; however, they have yielded inconsistent results. Most previous studies quantified oxygen exposure without considering its timing or duration. We investigated the relationship between unfavourable outcomes and supranormal arterial oxygen tension (PaO2 ), commonly defined as PaO2 > 100 mmHg, at specific time intervals within 24 h following CA. METHODS: This retrospective observational study included 838 adult non-traumatic patients with CA. The first 24 h following CA were divided into four 6-h time intervals, and the first 6-h period was further divided into three 2-h segments. Multivariable logistic regression analyses were conducted to assess associations of the highest PaO2 and time-weighted average PaO2 (TWA-PaO2 ) values at each time interval with unfavourable outcomes at hospital discharge (cerebral performance categories 3-5). RESULTS: The highest PaO2 (p = .028) and TWA-PaO2 (p = .022) values during the 0-6-h time interval were significantly associated with unfavourable outcomes, whereas those at time intervals beyond 6 h were not. The association was the strongest at supranormal PaO2 values within the 0-2-h time interval, becoming significant at PaO2 values ≥ 150 mmHg. During the first 6 h, longer time spent at ≥150 mmHg of PaO2 was associated with an increased risk of unfavourable outcomes (p = .038). The results were consistent across several sensitivity analyses. CONCLUSION: Supranormal PaO2 during but not after the first 6 h following cardiac arrest was independently associated with unfavourable outcomes.

External validation of cardiac arrest-specific prognostication scores developed for early prognosis estimation after out-of-hospital cardiac arrest in a Korean multicenter cohort.

We evaluated the performance of cardiac arrest-specific prognostication scores developed for outcome prediction in the early hours after out-of-hospital cardiac arrest (OHCA) in predicting long-term outcomes using independent data. The following scores were calculated for 1,163 OHCA patients who were treated with targeted temperature management (TTM) at 21 hospitals in South Korea: OHCA, cardiac arrest hospital prognosis (CAHP), C-GRApH (named on the basis of its variables), TTM risk, 5-R, NULL-PLEASE (named on the basis of its variables), Serbian quality of life long-term (SR-QOLl), cardiac arrest survival, revised post-cardiac arrest syndrome for therapeutic hypothermia (rCAST), Polish hypothermia registry (PHR) risk, and PROgnostication using LOGistic regression model for Unselected adult cardiac arrest patients in the Early stages (PROLOGUE) scores and prediction score by Aschauer et al. Their accuracies in predicting poor outcome at 6 months after OHCA were determined using the area under the receiver operating characteristic curve (AUC) and calibration belt. In the complete-case analyses, the PROLOGUE score showed the highest AUC (0.923; 95% confidence interval [CI], 0.904-0.941), whereas the SR-QOLl score had the lowest AUC (0.749; 95% CI, 0.711-0.786). The discrimination performances were similar in the analyses after multiple imputation. The PROLOGUE, TTM risk, CAHP, NULL-PLEASE, 5-R, and cardiac arrest survival scores were well calibrated. The rCAST and PHR risk scores showed acceptable overall calibration, although they showed miscalibration under the 80% CI level at extreme prediction values. The OHCA score, C-GRApH score, prediction score by Aschauer et al., and SR-QOLl score showed significant miscalibration in both complete-case (P = 0.026, 0.013, 0.005, and < 0.001, respectively) and multiple-imputation analyses (P = 0.007, 0.018, < 0.001, and < 0.001, respectively). In conclusion, the discrimination performances of the prognostication scores were all acceptable, but some showed significant miscalibration.

Effect of Epinephrine Administered during Cardiopulmonary Resuscitation on Cerebral Oxygenation after Restoration of Spontaneous Circulation in a Swine Model with a Clinically Relevant Duration of Untreated Cardiac Arrest.

Severe neurological impairment was more prevalent in cardiac arrest survivors who were administered epinephrine than in those administered placebo in a randomized clinical trial; short-term reduction of brain tissue O2 tension (PbtO2) after epinephrine administration in swine following a short duration of untreated cardiac arrest has also been reported. We investigated the effects of epinephrine administered during cardiopulmonary resuscitation (CPR) on cerebral oxygenation after restoration of spontaneous circulation (ROSC) in a swine model with a clinically relevant duration of untreated cardiac arrest. After 7 min of ventricular fibrillation, 24 pigs randomly received either epinephrine or saline placebo during CPR. Parietal cortex measurements during 60-min post-resuscitation period showed that the area under the curve (AUC) for PbtO2 was smaller in the epinephrine group than in the placebo group during the initial 10-min period and subsequent 50-min period (both p < 0.05). The AUC for number of perfused cerebral capillaries was smaller in the epinephrine group during the initial 10-min period (p = 0.005), but not during the subsequent 50-min period. In conclusion, epinephrine administered during CPR reduced PbtO2 for longer than 10 min following ROSC in a swine model with a clinically relevant duration of untreated cardiac arrest.

Pralidoxime improves the hemodynamics and survival of rats with peritonitis-induced sepsis.

Several studies have suggested that sympathetic overstimulation causes deleterious effects in septic shock. A previous study suggested that pralidoxime exerted a pressor effect through a mechanism unrelated to the sympathetic nervous system; this effect was buffered by the vasodepressor action of pralidoxime mediated through sympathoinhibition. In this study, we explored the effects of pralidoxime on hemodynamics and survival in rats with peritonitis-induced sepsis. This study consisted of two sub-studies: survival and hemodynamic studies. In the survival study, 66 rats, which survived for 10 hours after cecal ligation and puncture (CLP), randomly received saline placebo, pralidoxime, or norepinephrine treatment and were monitored for up to 24 hours. In the hemodynamic study, 44 rats were randomly assigned to sham, CLP-saline placebo, CLP-pralidoxime, or CLP-norepinephrine groups, and hemodynamic measurements were performed using a conductance catheter placed in the left ventricle. In the survival study, 6 (27.2%), 15 (68.1%), and 5 (22.7%) animals survived the entire 24-hour monitoring period in the saline, pralidoxime, and norepinephrine groups, respectively (log-rank test P = 0.006). In the hemodynamic study, pralidoxime but not norepinephrine increased end-diastolic volume (P <0.001), stroke volume (P = 0.002), cardiac output (P = 0.003), mean arterial pressure (P = 0.041), and stroke work (P <0.001). The pressor effect of norepinephrine was short-lived, such that by 60 minutes after the initiation of norepinephrine infusion, it no longer had any significant effect on mean arterial pressure. In addition, norepinephrine significantly increased heart rate (P <0.001) and the ratio of arterial elastance to ventricular end-systolic elastance (P = 0.010), but pralidoxime did not. In conclusion, pralidoxime improved the hemodynamics and 24-hour survival rate in rats with peritonitis-induced sepsis, but norepinephrine did not.

Association between ion shift index and prognosis in severe trauma patients without isolated head injury.

INTRODUCTION: This study aimed to investigate the ion shift index (ISI) as a prognostic factor of severe trauma. We hypothesized that the initial ISI measured in the emergency department (ED) is associated with discharge survival in severe non-isolated head injury (IHI) patients. MATERIALS AND METHODS: This retrospective observational study included severe trauma patients with available medical records from January 2017 to December 2018 but excluded those with IHI. Logistic regression analysis was conducted to identify the risk factors for mortality in non-IHI patients, and adjustments were performed for relevant covariates. An area under the receiver operating characteristics curve (AUROC) analysis was performed to examine the primary outcome of our study, which was mortality at hospital discharge in severe non-IHI trauma patients. RESULTS: Of the 483 severe non-IHI trauma patients included in the study, 86 patients (17.8 %) died. The multiple logistic regression analysis demonstrated ISI (odds ratio [OR], 2.300; 95% CI, 1.183-4.470) was significantly associated with mortality in the non-IHI group. Additionally, trauma and injury severity score (TRISS; OR, 0.538; 95% CI, 0.447-0.649), lactate (OR, 1.410; 95% CI, 1.252-1.588), creatinine (OR, 1.554; 95% CI, 1.221-1.979), and activated partial thromboplastin time (aPTT; OR, 1.050; 95% CI, 1.021-1.080) were independently associated with mortality at hospital discharge. The AUROC values for TRISS, lactate, aPTT, creatinine, and ISI were as follows: 0.892 (95% CI, 0.861-0.918), 0.838 (95% CI, 0.803-0.870), 0.754 (95% CI, 0.712-0.792), 0.650 (95% CI, 0.606-0.693), and 0.848 (95% CI, 0.813-0.879), respectively. The AUROC for the multiple logistic regression model with ISI was 0.942 (95% CI, 0.917-0.962). In a model in which TRISS was omitted, the addition of ISI to other predictors significantly improved the AUROC to 0.900 (95% CI, 0.869-0.925) (p=0.039). CONCLUSION: The initial ISI in the ED after trauma was associated with mortality in severe non-IHI trauma patients. In conjunction with other prognostic indicators, it could be used as an early prognostic marker, particularly if TRISS is unavailable.

Relationship of common hemodynamic and respiratory target parameters with brain tissue oxygen tension in the absence of hypoxemia or hypotension after cardiac arrest: A post-hoc analysis of an experimental study using a pig model.

Brain tissue oxygen tension (PbtO2)-guided care, a therapeutic strategy to treat or prevent cerebral hypoxia through modifying determinants of cerebral oxygen delivery, including arterial oxygen tension (PaO2), end-tidal carbon dioxide (ETCO2), and mean arterial pressure (MAP), has recently been introduced. Studies have reported that cerebral hypoxia occurs after cardiac arrest in the absence of hypoxemia or hypotension. To obtain preliminary information on the degree to which PbtO2 is responsive to changes in the common target variables for PbtO2-guided care in conditions without hypoxemia or hypotension, we investigated the relationships between the common target variables for PbtO2-guided care and PbtO2 using data from an experimental study in which the animals did not experience hypoxemia or hypotension after resuscitation. We retrospectively analyzed 170 sets of MAP, ETCO2, PaO2, PbtO2, and cerebral microcirculation parameters obtained during the 60-min post-resuscitation period in 10 pigs resuscitated from ventricular fibrillation cardiac arrest. PbtO2 and cerebral microcirculation parameters were measured on parietal cortices exposed through burr holes. Multiple linear mixed effect models were used to test the independent effects of each variable on PbtO2. Despite the absence of arterial hypoxemia or hypotension, seven (70%) animals experienced cerebral hypoxia (defined as PbtO2 <20 mmHg). Linear mixed effect models revealed that neither MAP nor ETCO2 were related to PbtO2. PaO2 had a significant linear relationship with PbtO2 after adjusting for significant covariates (P = 0.030), but it could explain only 17.5% of the total PbtO2 variance (semi-partial R2 = 0.175; 95% confidence interval, 0.086-0.282). In conclusion, MAP and ETCO2 were not significantly related to PbtO2 in animals without hypoxemia or hypotension during the early post-resuscitation period. PaO2 had a significant linear association with PbtO2, but its ability to explain PbtO2 variance was small.

PROLOGUE (PROgnostication using LOGistic regression model for Unselected adult cardiac arrest patients in the Early stages): Development and validation of a scoring system for early prognostication in unselected adult cardiac arrest patients.

BACKGROUND: Early prognostication after cardiac arrest would be useful. We aimed to develop a scoring model for early prognostication in unselected adult cardiac arrest patients. METHODS: We retrospectively analysed data of adult non-traumatic cardiac arrest patients treated at a tertiary hospital between 2014 and 2018. The primary outcome was poor outcome at hospital discharge (cerebral performance category, 3-5). Using multivariable logistic regression analysis, independent predictors were identified among known outcome predictors, that were available at intensive care unit admission, in patients admitted in the first 3 years (derivation set, N = 671), and a scoring system was developed with the variables that were retained in the final model. The scoring model was validated in patients admitted in the last 2 years (validation set, N = 311). RESULTS: The poor outcome rates at hospital discharge were similar between the derivation (66.0%) and validation sets (64.3%). Age <59 years, witnessed collapse, shockable rhythm, adrenaline dose <2 mg, low-flow duration <18 min, reactive pupillary light reflex, Glasgow Coma Scale motor score ≥2, and levels of creatinine <1.21 mg dl-1, potassium <4.4 mEq l-1, phosphate <5.8 mg dl-1, haemoglobin ≥13.2 g dl-1, and lactate <8 mmol l-1 were retained in the final multivariable model and used to develop the scoring system. Our model demonstrated excellent discrimination in the validation set (area under the curve of 0.942, 95% confidence interval 0.917-0.968). CONCLUSIONS: We developed a scoring model for early prognostication in unselected adult cardiac arrest patients. Further validations in various cohorts are needed.

Early Post-Rewarming Fever Is Associated with Favorable 6-Month Neurologic Outcomes in Patients with Out-Of-Hospital Cardiac Arrest: A Multicenter Registry Study.

We investigated the association between post-rewarming fever (PRF) and 6-month neurologic outcomes in cardiac arrest survivors. This was a multicenter study based on a registry of comatose adult (≥18 years) out-of-hospital cardiac arrest (OHCA) survivors who underwent targeted temperature management between October 2015 to December 2018. PRF was defined as peak temperature ≥ 38.0 °C within 72 h after completion of rewarming, and PRF timing was categorized as within 24, 24-48, and 48-72 h epochs. The primary outcome was neurologic outcomes at six months after cardiac arrest. Unfavorable neurologic outcome was defined as cerebral performance categories three to five. A total of 1031 patients were included, and 642 (62.3%) had unfavorable neurologic outcomes. PRF developed in 389 (37.7%) patients in 72 h after rewarming: within 24 h in 150 (38.6%), in 24-48 h in 155 (39.8%), and in 48-72 h in 84 (21.6%). PRF was associated with improved neurologic outcomes (odds ratio (OR), 0.633; 95% confidence interval (CI), 0.416-0.963). PRF within 24 h (OR, 0.355; 95% CI, 0.191-0.659), but not in 24-48 h or 48-72 h, was associated with unfavorable neurologic outcomes. Early PRF within 24 h after rewarming was associated with favorable neurologic outcomes.

Pralidoxime-Induced Potentiation of the Pressor Effect of Adrenaline and Hastened Successful Resuscitation by Pralidoxime in a Porcine Cardiac Arrest Model.

PURPOSE: Pralidoxime potentiated the pressor effect of adrenaline and facilitated restoration of spontaneous circulation (ROSC) after prolonged cardiac arrest. In this study, we hypothesised that pralidoxime would hasten ROSC in a model with a short duration of untreated ventricular fibrillation (VF). We also hypothesised that potentiation of the pressor effect of adrenaline by pralidoxime would not be accompanied by worsening of the adverse effects of adrenaline. METHODS: After 5 min of VF, 20 pigs randomly received either pralidoxime (40 mg/kg) or saline, in combination with adrenaline, during cardiopulmonary resuscitation (CPR). Coronary perfusion pressure (CPP) during CPR, and ease of resuscitation were compared between the groups. Additionally, haemodynamic data, severity of ventricular arrhythmias, and cerebral microcirculation were measured during the 1-h post-resuscitation period. Cerebral microcirculatory blood flow and brain tissue oxygen tension (PbtO2) were measured on parietal cortices exposed through burr holes. RESULTS: All animals achieved ROSC. The pralidoxime group had higher CPP during CPR (P = 0.014) and required a shorter duration of CPR (P = 0.024) and smaller number of adrenaline doses (P = 0.024). During the post-resuscitation period, heart rate increased over time in the control group, and decreased steadily in the pralidoxime group. No inter-group differences were observed in the incidences of ventricular arrhythmias, cerebral microcirculatory blood flow, and PbtO2. CONCLUSION: Pralidoxime improved CPP and hastened ROSC in a model with a short duration of untreated VF. The potentiation of the pressor effect of adrenaline was not accompanied by the worsening of the adverse effects of adrenaline.

Effects of Different Doses of Pralidoxime Administered During Cardiopulmonary Resuscitation and the Role of α-Adrenergic Receptors in Its Pressor Action.

Background We previously reported that pralidoxime facilitated restoration of spontaneous circulation by potentiating the pressor effect of epinephrine. We determined the optimal dose of pralidoxime during cardiopulmonary resuscitation and evaluated the involvement of α-adrenoceptors in its pressor action. Methods and Results Forty-four pigs randomly received 1 of 3 doses of pralidoxime (40, 80, or 120 mg/kg) or saline placebo during cardiopulmonary resuscitation, including epinephrine administration. Pralidoxime at 40 mg/kg produced the highest coronary perfusion pressure, whereas 120 mg/kg of pralidoxime produced the lowest coronary perfusion pressure. Restoration of spontaneous circulation was attained in 4 (36.4%), 11 (100%), 9 (81.8%), and 3 (27.3%) animals in the saline, 40, 80, and 120 mg/kg groups, respectively (P<0.001). In 49 rats, arterial pressure response to 40 mg/kg of pralidoxime was determined after saline, guanethidine, phenoxybenzamine, or phentolamine pretreatment, and the response to 200 mg/kg pf pralidoxime was determined after saline, propranolol, or phentolamine pretreatment. Pralidoxime at 40 mg/kg elicited a pressor response. Phenoxybenzamine completely inhibited the pressor response, but guanethidine and phentolamine did not. The pressor response of pralidoxime was even greater after guanethidine or phentolamine pretreatment. Pralidoxime at 200 mg/kg produced an initial vasodepressor response followed by a delayed pressor response. Unlike propranolol, phentolamine eliminated the initial vasodepressor response. Conclusions Pralidoxime at 40 mg/kg administered with epinephrine improved restoration of spontaneous circulation rate by increasing coronary perfusion pressure in a pig model of cardiac arrest, whereas 120 mg/kg did not improve coronary perfusion pressure or restoration of spontaneous circulation rate. The pressor effect of pralidoxime was unrelated to α-adrenoceptors and buffered by its vasodepressor action mediated by sympathoinhibition.

Turn-to-Shockable Rhythm Has Comparable Neurologic Outcomes to Initial Shockable Rhythm in Out-of-Hospital Cardiac Arrest Patients Who Underwent Targeted Temperature Management.

Shockable rhythm in out-of-hospital cardiac arrest (OHCA) implies better outcome and underlying coronary stenosis. We investigated the neurologic outcome and coronary lesions between initial shockable rhythm and turn-to-shockable rhythm. This multicenter, retrospective observational study included adult nontraumatic OHCA survivors with any shockable rhythm during cardiopulmonary resuscitation (CPR) who underwent targeted temperature management between January 2010 and December 2016. Patients were divided into two groups according to the first monitored rhythm: initial shockable rhythm or turn-to-shockable rhythm. The primary outcome was good neurologic outcome at discharge based on cerebral performance categories, and the secondary outcomes were survival discharge, recurrent arrest, and coronary lesions. The two groups were matched in a 1:1 ratio using propensity score (PS). Of 426 patients, 137 and 289 patients were divided into the turn-to-shockable and initial shockable rhythm groups, respectively. Overall, 224 (52.6%) patients had good neurologic outcomes. The turn-to-shockable rhythm group had less patients with good neurologic outcome (57/137 vs. 167/289; p = 0.002) and less culprit lesions in the left anterior descending and left circumflex arteries. However, survival discharge and recurrent arrest were not different between the two groups, and the turn-to-shockable rhythm had no independent association with neurologic outcome (odds ratio, 1.874; 95% confidence interval, 0.909-3.863). In the PS-matched cohort, the turn-to-shockable rhythm group had similar good neurologic outcome (47/100 vs. 35/100, p = 0.083). Survival discharge, recurrent arrest, and coronary culprit lesions were not different between the two groups. In this PS-matched study, OHCA with any shockable rhythm during CPR had similar neurologic outcome and coronary culprit lesions, irrespective of the first monitored rhythm.

Pralidoxime administered during cardiopulmonary resuscitation facilitates successful resuscitation in a pig model of cardiac arrest.

Pralidoxime is a common antidote for organophosphate poisoning; however, studies have also reported pralidoxime's pressor effect, which may facilitate the restoration of spontaneous circulation (ROSC) after cardiac arrest by improving coronary perfusion pressure (CPP). We investigated the immediate cardiovascular effects of pralidoxime in anaesthetised normal rats and the effects of pralidoxime administration during cardiopulmonary resuscitation (CPR) in a pig model of cardiac arrest. To evaluate the immediate cardiovascular effects of pralidoxime, seven anaesthetised normal rats received saline or pralidoxime (20 mg/kg) in a randomised crossover design, and the responses were determined using the conductance catheter technique. To evaluate the effects of pralidoxime administration during CPR, 22 pigs randomly received either 80 mg/kg of pralidoxime or an equivalent volume of saline during CPR. In the rats, pralidoxime significantly increased arterial pressure than saline (P = .044). The peak effect on arterial pressure was observed in the first minute. In a pig model of cardiac arrest, CPP during CPR was higher in the pralidoxime group than in the control group (P = .002). ROSC was attained in three animals (27.3%) in the control group and nine animals (81.8%) in the pralidoxime group (P = .010). Three animals (27.3%) in the control group and eight animals (72.2%) in the pralidoxime group survived the 6-hour period (P = .033). In conclusion, pralidoxime had a rapid onset of pressor effect. Pralidoxime administered during CPR led to significantly higher rates of ROSC and 6-hour survival by improving CPP in a pig model.

The association between lipid profiles and the neurologic outcome in patients with out-of-hospital cardiac arrest.

BACKGROUND: Lipid profiles are known to be a risk factor for development of cardiovascular disease. However, the relationship between lipid profiles and outcome in out-of-hospital cardiac arrest (OHCA) survivors remains unclear. We aimed to examine the association between lipid profiles and neurologic outcome in OHCA survivors. METHODS: This retrospective observational study included adult (≥18 years) OHCA survivors between January 2016 and December 2018. We measured patients' lipid profiles after return of spontaneous circulation (ROSC) including total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL), and triglyceride. The primary outcome was neurologic outcome at hospital discharge. Good neurologic outcome was defined cerebral performance categories 1 and 2. RESULTS: A total of 182 patients were included. Of them, 57 (31.3%) were discharged with good neurologic outcomes. Median serum levels of total cholesterol (178.0 vs. 123.0 mg/dL), HDL (44.0 vs. 31.0 mg/dL), and LDL (104.0 vs. 75.0 mg/dL) were significantly higher in patients with good neurologic outcome. The area under the curves of total cholesterol, HDL, LDL, and triglyceride were 0.742 (95% confidence interval [CI], 0.672-0.803), 0.729 (95% CI, 0.658-0.792), 0.683 (95% CI, 0.610-0.750), and 0.572 (95% CI, 0.497-0.645), respectively. Total cholesterol (odds ratio [OR], 1.013; 95% CI, 1.000-1.025; p = 0.043) and HDL (OR, 1.071; 95% CI, 1.021-1.123; p = 0.005) levels were associated with good neurologic outcomes. CONCLUSIONS: The levels of total cholesterol and HDL after ROSC were associated with good neurologic outcomes in patients with OHCA, without considering the effect of other lipid profiles simultaneously.

Effect of pralidoxime on coronary perfusion pressure during cardiopulmonary resuscitation in a pig model.

Objective: Pralidoxime is widely used for the treatment of organophosphate poisoning. Multiple studies have reported its vasoconstrictive property, which may facilitate the restoration of spontaneous circulation (ROSC) after cardiac arrest by increasing the coronary perfusion pressure (CPP). 2,3-Butanedione monoxime, which belongs to the same oxime family, has been shown to facilitate ROSC by reducing left ventricular ischemic contracture. Because pralidoxime and 2,3-butanedione monoxime have several common mechanisms of action, both drugs may have similar effects on ischemic contracture. Thus, we investigated the effects of pralidoxime administration during cardiopulmonary resuscitation in a pig model with a focus on ischemic contracture and CPP. Methods: After 14 minutes of untreated ventricular fibrillation, followed by 8 minutes of basic life support, 16 pigs randomly received either 80 mg/kg of pralidoxime (pralidoxime group) or an equivalent volume of saline (control group) during advanced cardiovascular life support (ACLS). Results: Mixed-model analyses of left ventricular wall thickness and chamber area during ACLS revealed no significant group effects or group-time interactions, whereas a mixed-model analysis of the CPP during ACLS revealed a significant group effect (P=0.038) and group-time interaction (P<0.001). Post-hoc analyses revealed significant increases in CPP in the pralidoxime group, starting at 5 minutes after pralidoxime administration. No animal, except one in the pralidoxime group, achieved ROSC; thus, the rate of ROSC did not differ between the two groups. Conclusion: In a pig model of cardiac arrest, pralidoxime administered during cardiopulmonary resuscitation did not reduce ischemic contracture; however, it significantly improved CPP.

Ion shift index as a promising prognostic indicator in adult patients resuscitated from cardiac arrest.

BACKGROUND: Several studies reported that disturbances in cellular ion homeostasis occur following ischaemia, the magnitude of which was proportional to illness severity. The changes in serum electrolyte levels following ischaemia were minor compared with the changes in ion concentrations in the extracellular fluid. To amplify the serum electrolyte changes, we devised a new index (ion shift index), which could be calculated using commonly measured serum electrolyte levels, and explored its prognostic value in adult cardiac arrest patients. METHODS: This retrospective observational study included adult cardiac arrest survivors treated at a tertiary university hospital between January 2014 and December 2017. Using the first available serum electrolyte levels, the ion shift index was calculated as follows: ion shift index = (potassium + phosphate + magnesium) / calcium. The primary outcome was poor outcome at hospital discharge (cerebral performance categories 3-5). RESULTS: The area under the receiver operating characteristic curve (AUC) of ion shift index for predicting poor outcome was 0.878 (95% confidence interval [CI], 0.849-0.907). The AUC of ion shift index was greater than those of individual electrolytes (all p < 0.001). In multivariate analysis, higher ion shift index levels were independently associated with poor outcome (odds ratio, 2.916; 95% CI, 1.798-4.730; p < 0.001). The AUC of multivariate model including ion shift index was greater than that of multivariate model after excluding ion shift index (p = 0.007). CONCLUSIONS: Our results suggest that the ion shift index can be helpful in the early prognostication of adult cardiac arrest patients.

Relationship between ventricular characteristics on brain computed tomography and 6-month neurologic outcome in cardiac arrest survivors who underwent targeted temperature management.

AIM OF THE STUDY: Brain swelling after cardiac arrest may affect the ventricles. We aimed to investigate the prognostic performance of ventricular characteristics on brain computed tomography (CT) in cardiac arrest survivors who underwent targeted temperature management (TTM). METHODS: This retrospective cohort study included adult comatose cardiac arrest survivors who underwent brain CT scan within 24 h after resuscitation and underwent TTM from 2014 to 2016. The ventricular areas (lateral, third, and fourth ventricle), distances between the anterior horns of the lateral ventricle (LV) and the posterior horns of the LV, and maximal internal diameter of the skull were measured. Grey-to-white matter ratio (GWR), Evans' index, and relative LV area were calculated. The primary outcome was a 6-month neurologic outcome. RESULTS: Of 258 patients, 176 (68.2%) had an unfavourable neurologic outcome. GWR, LV area, third ventricle area, distance between the anterior horns of the LV, distance between the posterior horns of the LV, Evans' index, and relative LV area were different between neurologic outcome groups. Evans' index (0.683; 95% confidence interval [CI], 0.623-0.739) and relative LV area (0.670; 95% CI, 0.609-0.727) had higher value of area under the curve than the other ventricular characteristics and showed prognostic performance comparable with GWR (0.600; 95% CI, 0.538-0.661). All ventricular characteristics and GWR were not independently associated with neurologic outcome after adjusting for covariates. CONCLUSION: Ventricular characteristics on brain CT were associated with 6 months neurologic outcome in cardiac arrest survivors. Ventricular characteristics were objective measures that had comparable prognostic performance with GWR.

Prognostic value of serum phosphate level in adult patients resuscitated from cardiac arrest.

BACKGROUND: Several studies have reported increased levels of phosphate after cardiac arrest. Given the relationship between phosphate level and the severity of ischaemic injury reported in previous studies, higher phosphate levels may be associated with worse outcomes. We investigated the prognostic value of phosphate level after the restoration of spontaneous circulation (ROSC) in adult cardiac arrest patients. METHODS: This study was a retrospective observational study including adult cardiac arrest survivors treated at the Chonnam National University Hospital between January 2014 and June 2017. From medical records, data regarding clinical characteristics, outcome at hospital discharge, and laboratory parameters including phosphate levels after ROSC were collected. The primary outcome was poor outcome at hospital discharge, defined as Cerebral Performance Categories 3-5. RESULTS: Of the 674 included patients, 465 had poor outcome at hospital discharge. Serum phosphate level was significantly higher in patients with poor outcome than in those with good outcome (p < 0.001). Phosphate level was correlated with time to ROSC (r = 0.350, p < 0.001). Receiver operating characteristic curve analysis revealed an area under the curve of 0.805 (95% confidence interval [CI], 0.777-0.838) for phosphate level. In multivariate analysis, a higher phosphate level was independently associated with poor outcome at hospital discharge (odds ratio, 1.432; 95% CI, 1.245-1.626; p < 0.001). CONCLUSIONS: A higher phosphate level after ROSC was independently associated with poor outcome at hospital discharge in adult cardiac arrest patients. However, given its modest prognostic performance, phosphate level should be used in combination with other prognostic indicators.

Effect of one-lung ventilation on end-tidal carbon dioxide during cardiopulmonary resuscitation in a pig model of cardiac arrest.

Unrecognized endobronchial intubation frequently occurs after emergency intubation. However, no study has evaluated the effect of one-lung ventilation on end-tidal carbon dioxide (ETCO2) during cardiopulmonary resuscitation (CPR). We compared the hemodynamic parameters, blood gases, and ETCO2 during one-lung ventilation with those during conventional two-lung ventilation in a pig model of CPR, to determine the effect of the former on ETCO2. A randomized crossover study was conducted in 12 pigs intubated with double-lumen endobronchial tube to achieve lung separation. During CPR, the animals underwent three 5-min ventilation trials based on a randomized crossover design: left-lung, right-lung, or two-lung ventilation. Arterial blood gases were measured at the end of each ventilation trial. Ventilation was provided using the same tidal volume throughout the ventilation trials. Comparison using generalized linear mixed model revealed no significant group effects with respect to aortic pressure, coronary perfusion pressure, and carotid blood flow; however, significant group effect in terms of ETCO2 was found (P < 0.001). In the post hoc analyses, ETCO2 was lower during the right-lung ventilation than during the two-lung (P = 0.006) or left-lung ventilation (P < 0.001). However, no difference in ETCO2 was detected between the left-lung and two-lung ventilations. The partial pressure of arterial carbon dioxide (PaCO2), partial pressure of arterial oxygen (PaO2), and oxygen saturation (SaO2) differed among the three types of ventilation (P = 0.003, P = 0.001, and P = 0.001, respectively). The post hoc analyses revealed a higher PaCO2, lower PaO2, and lower SaO2 during right-lung ventilation than during two-lung or left-lung ventilation. However, the levels of these blood gases did not differ between the left-lung and two-lung ventilations. In a pig model of CPR, ETCO2 was significantly lower during right-lung ventilation than during two-lung ventilation. However, interestingly, ETCO2 during left-lung ventilation was comparable to that during two-lung ventilation.

The effectiveness of using magnetic resonance imaging in syncope patients visiting an emergency department: A case-control study.

OBJECTIVE: To evaluate the effectiveness of brain magnetic resonance imaging in excluding neurological causes in patients with syncope. METHODS: This retrospective, observational, cohort study was conducted at the Chonnam National University Hospital, Gwangju, South Korea, and comprised medical record of patients with syncope from January 2011 to February 2016. The ratio of abnormal findings, the characteristics of the patients who showed abnormal findings and the relationships between the presence of neurological problem and other clinical factors were analysed. SPSS 18 was used for statistical analysis. RESULTS: Of the 1,045 patients, 142(13.5%) underwent additional magnetic resonance imaging. The results showed that 15(10.6%) patients had abnormal findings indicating neurological problems; of them, 9(60%) showed vascular stenosis, 4(27%) showed cerebral infarction, and 2(13%) showed brain tumours. The neurological problems shown were significantly higher for older patients (p=0.006) and those with the underlying diseases of hypertension (p=0.014) and coronary artery disease (p=0.008). Of these patients in particular, age (p=0.036) and history of coronary artery disease (p=0.029) were significantly associated with abnormal findings in their magnetic resonance imaging. CONCLUSIONS: Although there are no specific neurological examinations or computed tomography findings currently used in patients with syncope in the emergency department, magnetic resonance imaging may be performed to exclude neurological causes in older patients as well as those with a history of coronary artery disease.

Disseminated intravascular coagulation is associated with the neurologic outcome of cardiac arrest survivors.

PURPOSE: We aimed to examine the serial changes in coagulofibrinolytic markers that occurred after the restoration of spontaneous circulation (ROSC) in cardiac arrest patients, who were treated with targeted temperature management (TTM). We also evaluated the association between the disseminated intravascular coagulation (DIC) score and clinical outcomes. METHODS: This was a single-centre, retrospective observational study that included cardiac arrest patients who were treated with TTM from May 2012 to December 2015. The prothrombin time (PT) and partial thromboplastin time (PTT), along with the levels of fibrinogen, fibrin degradation products (FDP), and D-dimer were obtained after ROSC and on day 1, 2, and 3. The DIC score was calculated after ROSC. The primary outcome was the neurologic outcome at discharge and the secondary outcome was the 6-month mortality. RESULTS: This study included 317 patients. Of these, 222 (70.0%) and 194 (61.2%) patients had a poor neurologic outcome at discharge and 6-month mortality, respectively. The PT, PTT, and fibrinogen level significantly increased over time, while the FDP and D-dimer levels decreased during first three days after ROSC. Multivariate logistic analyses revealed that the DIC score remained a significant predictor for poor neurologic outcome (odds ratio [OR], 1.800; 95% confidence interval [CI], 1.323-2.451) and 6-month mortality (OR, 1.773; 95% CI, 1.307-2.405). CONCLUSION: The activity of coagulation and fibrinolysis decreased over time. An increased DIC score was an independent prognostic factor for poor neurologic outcome and 6-month mortality.