Vasopressin in cardiac arrest

OBJECTIVE: To review the efficacy and safety of vasopressin in cardiac arrest. DATA SOURCES: MEDLINE, EMBASE, and PubMed were searched (all to June 2005) for full-text English-language publications describing trials in humans. Search terms were vasopressin, epinephrine, adrenaline, heart arrest, cardiac arrest, and clinical trial. STUDY SELECTION AND DATA EXTRACTION: Prospective, randomized, controlled trials that evaluated efficacy or safety endpoints of vasopressin in the management of cardiac arrest were included. Efficacy outcomes included return of spontaneous circulation, successful resuscitation, survival to hospital admission, 24-hour survival, and survival to hospital discharge. Safety outcomes were as defined by each trial. DATA SYNTHESIS: Three prospective trials were identified and included in this review. Vasopressin does not appear to offer any therapeutic advantage compared with epinephrine in the treatment of both in-hospital and out-of-hospital cardiac arrest, regardless of the presenting arrest rhythm. Although there is a suggestion that vasopressin may be effective in treatment of asystole, the evidence for this arises from a subgroup analysis that should be viewed as hypothesis generating. There are limited data describing the safety of vasopressin in cardiac arrest. CONCLUSIONS: The current evidence for the use of vasopressin in cardiac arrest is indeterminate. Given the similarly equivocal evidence of efficacy for epinephrine, either drug could be considered the first-line agent in cardiac arrest. Placebo-controlled studies with appropriate statistical power are warranted to evaluate meaningful clinical outcomes, such as survival to hospital discharge. Further evaluation of the role of vasopressin in asystolic cardiac arrest and its use in combination with epinephrine is also justified.     

Sedation in the ICU

The effect of midazolam on the induction dose-response curve for alfentanil was studied in non-premedicated ASA physical status I or II patients. The response to the verbal command was used as an end point of anaesthesia. Dose-response curves for midazolam, alfentanil, and their combination were determined with a probit procedure, and compared with algebraic (fractional) analysis of drug interaction. Interaction between midazolam and alfentanil was found to be synergistic (supra-additive). The results suggest that the use of this combination is advantageous not only because it helps to achieve different anaesthetic goals with specific drugs (a benzodiazepine for unconsciousness and an opioid for blockade of the responses to noxious stimulation), but also because its components are complementary for unconsciousness.     

Ethics in the ICU

The power to heal and create "good" in intensive care also stimulates great ethical conflict and discourse. Palliation and end of life issues in intensive care are beginning to be clearly defined and enhanced for the good of the patients. After decades of striving to save life to the very extreme, we are now providing that same effort toward end of life care. The last decade has brought consumerism or medicine's interpretation of such, far beyond any boundaries previously imagined. Issues of power, team communication, and family decision making strategies should hold a higher priority in the ICU. Empowered nurses in authority can make the key difference in when and how ethical resolutions occur.     

Sedation in the ICU

The effect of midazolam on the induction dose-response curve for alfentanil was studied in non-premedicated ASA physical status I or II patients. The response to the verbal command was used as an end point of anaesthesia. Dose-response curves for midazolam, alfentanil, and their combination were determined with a probit procedure, and compared with algebraic (fractional) analysis of drug interaction. Interaction between midazolam and alfentanil was found to be synergistic (supra-additive). The results suggest that the use of this combination is advantageous not only because it helps to achieve different anaesthetic goals with specific drugs (a benzodiazepine for unconsciousness and an opioid for blockade of the responses to noxious stimulation), but also because its components are complementary for unconsciousness.     

Noise in the ICU

Objective The growing number of technical devices in ICUs makes noise exposure a major stressor. The purpose of this study was to assess noise levels during routine operation in our ICU.Design Our ICU is an open ward with four rooms, constructed in the 1960s. During the study period, 4 patients were in the controlled room and were treated by 4 nurses during the day and by 2 at night. A-weighted sound pressure levels (SPL) were measured continuously for 2 days and nights. Also measured were the alarms of various appliances. For gross overall evaluation it is customary to state the L_eq, i.e. the energy-averaged level during measurement. The annoyance caused by noise depends more on rare events of high intensity. Therefore, the distribution of SPL values (L_n) over time was also analysed.Results SPL was roughly the same during the day and at night, with L_eq between 60–65 dB(A) and peaks up to 96 dB(A). Most alarms reach an SPL of 60–70 dB(A), but some exceed 80 dB(A). During teaching rounds L_eq exceeds 65 dB(A).Conclusion During the day and at night SPL always surpasses the permissible noise exposure for 24 h of 45 db(A) recommended by the US Environmental Protection Agency. Alarms cause the most irritating noise. Hospital management should pay attention to internal noise, and SPL should be measured routinely.