Safety of gelatin for volume resuscitation--a systematic review and meta-analysis.

PURPOSE: Gelatin is frequently used as a volume expander in critical care. Our goal was to investigate its safety. METHODS: Systematic review of randomized controlled trials (RCT) in patients receiving gelatin for resuscitation in comparison to albumin or crystalloids. RESULTS: We identified 40 RCTs published between 1976 and 2010 with 3,275 patients. Median sample size in the gelatin groups was 15 patients (range 10-249). Median gelatin dose was 17 ml/kg (range 6-57 ml/kg). In 32 RCTs (n = 1,946/3,275, 59 % of all patients), the study period was ≤24.0 h. Twenty-nine RCTs (n = 2,001) investigated elective surgical patients, mostly undergoing cardiac surgery (18 RCTs, n = 819). Three RCTs (n = 723) investigated critically ill adults. Two RCTs (n = 59) were performed in emergency room patients, and six RCTs (n = 492) were performed in neonates or children. No study was adequately powered to investigate the frequency of patient-important outcomes. Risks were not statistically significantly different for mortality (RR 1.12, 95 % confidence interval, 0.87-1.44) and exposure to allogeneic transfusion (RR 1.28, 0.89-1.83). On account of only few included studies and the small number of patients, subgroup analyses (high vs. low dose, >24 h vs. shorter periods, and critically ill patients vs. others) were uninformative. Only three RCTs reported the occurrence of acute renal failure. CONCLUSION: Despite over 60 years of clinical practice, the safety and efficacy of gelatin cannot be reliably assessed in at least some settings in which it is currently used. We suggest the need to investigate and establish such safety.

Disparate hemodynamic responses to mental challenge after antihypertensive therapy with beta blockers and calcium entry blockers.

The hemodynamic response to mental challenge was studied in 40 male outpatients with mild essential hypertension. The patients were treated randomly either with a beta adrenoreceptor blocker (oxprenolol) or with a calcium entry blocker (nitrendipine). Cardiovascular reactivity was evaluated with two different mental arithmetic tasks before and six months after treatment by continuously measuring systolic and diastolic pressure (ultrasonic Doppler device), heart rate (electrocardiography), and stoke volume (impedance cardiography). Patients in both treatment groups had equal decreases in arterial pressure and the same pressures at rest. In patients receiving calcium entry blockers, mental challenge provoked an increase in stroke volume and a decrease in total peripheral resistance similar to results in the pretreatment phase. In contrast, beta adrenoreceptor blockade reversed the hemodynamic response pattern to a distinct decrease in stroke volume (p less than or equal to 0.05) and an increase in total peripheral resistance (p less than or equal to 0.05). In addition, an attenuated heart rate response (p less than or equal to 0.01) and a larger increase in diastolic pressure (p less than or equal to 0.01) were found in the beta blocker group compared with the calcium entry blocker group. Although beta blockers and calcium blockers produce equal decreases in arterial pressure, beta blockers evoke an abnormal hemodynamic response to mental challenge, whereas calcium entry blockers preserve the physiologic reactivity pattern of the untreated state.