A systematic review of cerebral oxygenation-monitoring devices in cardiac surgery.

OBJECTIVE: Cerebral oxygenation monitoring via near-infrared spectroscopy (NIRS) during cardiopulmonary bypass (CPB) is increasingly becoming an accepted and valued component of intraoperative monitoring. In recent years, new devices have become available which all make different claims. The purpose of this study is to examine the research on these individual devices to establish the levels of evidence for each and formulate a research path for further evaluation of this technology in cardiac surgery. METHODS: This study is a systematic review of published research on cerebral oximetry. We searched PubMed, CINAHL and Scopus for full-length, peer-reviewed articles containing original data resulting from the study of patient neurologic outcomes based on the use of FDA-approved near-infrared spectroscopy devices. The studies were then grouped and classified based on the device used and the levels of evidence each study provided. RESULTS: Only a very limited number of high-level clinical evidence research papers are currently available, with nearly all of those papers based on the INVOS system. This is likely due to the different lengths of time each device has been on the market and its availability for use in clinical trials. Challenges to testing include the expense of testing various devices, the lack of a globally accepted gold standard for cerebral oxygenation saturation, the limited availability of patient frontal surface area and the gradual adoption of this technology. Despite these limitations, significant results have been identified in relation to patient outcomes. CONCLUSION: At this time, there is limited high-level evidence available for all of the NIRS devices on the market despite significant outcomes found in these studies. Additional prospective randomized studies should be conducted in order to establish the potential role NIRS may play in patient monitoring as well as assessing the efficacy of the multiple devices on the market.

Echocardiographic incidence of pericardial effusion in patients resuscitated by emergency medical technicians.

The incidence of echocardiographically determined pericardial effusion was assessed in the early postmanual cardiopulmonary resuscitation (CPR) period in a group of patients resuscitated by advanced emergency medical technicians (EMT-P) from the Rescue Division of the Tampa Fire Department. The survival rate from out-of-hospital sudden death is comparable to that reported in other series. Twenty-six survivors of out-of-hospital sudden death had echocardiograms performed an average of 2.5 days (range 0-10) postCPR to determine the amount of pericardial effusion. Eight of the 26 (31%) patients had received intracardiac drugs during CPR administered by the EMT-Ps when physician-directed by radio. Of the 26, three (12%) were found to have very minimal pericardial effusions; all deemed insignificant. All three had alternate explanations for physiological or pathological causes of their effusions. One had received intracardiac drugs, but the pericardial effusion could be explained by congestive cardiomyopathy. Another had congestive cardiomyopathy, and the third had sustained a severe steering wheel injury to the chest. Thus, manual CPR with or without the use of intracardiac drugs does not appear to cause significant pericardial effusions in survivors of sudden cardiac death.

Paramedic use of intracardiac medications in prehospital sudden cardiac death.

The intracardiac administration of medications in cardiac arrest is advocated when an intravenous route cannot be established. Although warnings of complications of this mode of therapy are reiterated throughout the literature, their careful documentation is lacking. Paramedics were trained to administer intracardiac medications, under strict criteria, in patients with prehospital sudden cardiac death. Long-term survivors who received intracardiac medications from paramedics were compared to a control group resuscitated by paramedics with intravenous medications alone. By far, the patients who received intracardiac medications were more nearly refractory to resuscitation because of the criteria for intracardiac medication use. Potential complications of the intracardiac route were identified and sought. However, complications were no more common in this group of patients than in the control group. Paramedics can successfully administer intracardiac medications when indicated.

Onset of Prinzmetal's angina two years following sudden death syndrome survival.

A patient who was resuscitated after an episode of ventricular fibrillation without myocardial infarction outside the hospital developed angina for the first time two years later. Although the clinical pattern did not fulfill all of the criteria of Prinzmetal's variant angina and was found to correspond with episodes of ventricular tachycardia, we feel that Prinzmetal's angina can be implicated as the mechanism of previos ventricular fibrillation. During the patient's second hospitalization, angiography demonstrated a single, moderately stenotic, right coronary lesion which was bypassed. Immediately postoperatively, the patient developed ventricular fibrillation requiring more than two hours of cardiopulmonary resuscitation. Six months after bypass surgery, she experienced an inferior wall myocardial infarction. She is presently asymptomatic with normal heart size.

Sudden cardiac death: a retrospective and prospective study.

Since the inception of mobile coronary care units (MCCU), patients with sudden cardiac death (SCD) saved by advanced emergency medical technicians (EMT-A) can be studied retrospectively and prospectively. Forty-eight cases of SCD found in ventricular fibrillation (VF) were successfully resuscitated. Only 32% had a myocardial infarction. Most survivors were New York Heart Association (NYHA) class I or II. All class IV survivors with severe congestive heart failure died within 45 days. All class II survivors had angina as the limiting factor. Of all patients with VF, 23% survived. Eighty percent of survivors were class I or II and have resumed previous lifestyles. No clear cut symptom complex was identified. Rescue response time was generally less than five minutes. Intracardiac medications were administered without complications. Empirical administration of sodium bicarbonate correlated poorly with arterial blood gas determinations.