Successful resuscitation using nitroglycerin for refractory pulseless electrical activity in intensive care unit

Search for Therapeutic Agents for Cardiac Arrest Using a Drug Discovery Tool and Large-Scale Medical Information Database

The survival rate of cardiac arrest patients is less than 10%; therefore, development of a therapeutic strategy that improves their prognosis is necessary. Herein, we searched data collected from medical facilities throughout Japan for drugs that improve the survival rate of cardiac arrest patients. Candidate drugs, which could improve the prognosis of cardiac arrest patients, were extracted using “TargetMine,” a drug discovery tool. We investigated whether the candidate drugs were among the drugs administered within 1 month after cardiac arrest in data of cardiac arrest cases obtained from the Japan Medical Data Center. Logistic regression analysis was performed, with the explanatory variables being the presence or absence of the administration of those candidate drugs that were administered to ≥10 patients and the objective variable being the “survival discharge.” Adjusted odds ratios for survival discharge were calculated using propensity scores for drugs that significantly improved the proportion of survival discharge; the influence of covariates, such as patient background, medical history, and treatment factors, was excluded by the inverse probability-of-treatment weighted method. Using the search strategy, we extracted 165 drugs with vasodilator activity as candidate drugs. Drugs not approved in Japan, oral medicines, and external medicines were excluded. Then, we investigated whether the candidate drugs were administered to the 2,227 cardiac arrest patients included in this study. The results of the logistic regression analysis showed that three (isosorbide dinitrate, nitroglycerin, and nicardipine) of seven drugs that were administered to ≥10 patients showed significant association with improvement in the proportion of survival discharge. Further analyses using propensity scores revealed that the adjusted odds ratios for survival discharge for patients administered isosorbide dinitrate, nitroglycerin, and nicardipine were 3.35, 5.44, and 4.58, respectively. Thus, it can be suggested that isosorbide dinitrate, nitroglycerin, and nicardipine could be novel therapeutic agents for improving the prognosis of cardiac arrest patients.

The effects of nitroglycerin during cardiopulmonary resuscitation

The outcome for both in-hospital and out-of hospital cardiac arrest remains dismal. Vasopressors are used to increase coronary perfusion pressure and thus facilitate return of spontaneous circulation during cardiopulmonary resuscitation. However, they are associated with a number of potential adverse effects and may decrease endocardial and cerebral organ blood flow. Nitroglycerin has a favourable haemodynamic profile which promotes forward blood flow. Several studies suggest that combined use of nitroglycerin with vasopressors during resuscitation, is associated with increased rates of resuscitation and improved post-resuscitation outcome. This article reviews the effects of nitroglycerin during cardiopulmonary resuscitation and postresuscitation period, as well as the beneficial outcomes of a combination regimen consisting of a vasopressor and a vasodilator, such as nitroglycerin.

Vasopressin with delayed combination of nitroglycerin increases survival rate in asphyxia rat model

Recently, vasopressin has been reported as a more effective drug than epinephrine (adrenaline) for cardiopulmonary resuscitation (CPR). However, vasopressin decreases myocardial blood flow (MBF) because of its strong vasoconstriction, to maintain better coronary perfusion pressure (CPP) compared with epinephrine. Nitroglycerin is well known to be able to maintain MBF and increase survival rate. In a VF model, vasopressin combined with nitroglycerin maintained CPP; however, low survival rates were observed compared with vasopressin alone. We investigated the effectiveness of the delayed use of nitroglycerin combined with vasopressin in a severe asphyxia model. Fourteen Sprague-Dawley male rats were divided into two groups: vasopressin 0.8 U/kg alone (V-Gr.), and nitroglycerin 0.3 microg/kg 45 s after the administration of 0.8 U/kg vasopressin (VN-Gr.). Six min after asphyxia induced by obstructing the tracheal tube, CPR was performed in two ways. Three animals resuscitated in the V-Gr. (42%) and six/seven (84%) in the VN-Gr. (P<0.05). In the 6 min of asphyxia rat model, vasopressin combined with delayed nitroglycerin is more effective than vasopressin alone.