Improvement in chest compression quality using a feedback device (CPRmeter): a simulation randomized crossover study.

PURPOSES: Cardiac arrest survival depends on celerity and efficiency of life support action. Guidelines emphasized the chest compression (CC) quality and feedback devices are encouraged. The purpose is to study the impact of the CPRmeter feedback device on resuscitation performed by untrained rescuers. BASIC PROCEDURES: This is a prospective randomized crossover study on manikins (Resusci Anne). One hundred and forty four students inexperienced in cardiopulmonary resuscitation representing untrained rescuers were included. Participants performed 2 minutes of CC without interruption with (group G) or without (group B) feedback. Four months passed between the 2 crossover phases to avoid resilience effect. Data collected by the CPRmeter device were: CC rate, depth and release. MAIN FINDINGS: Efficient CC rate ([simultaneous and correct CC rate, depth and release] primary outcome) (absolute difference [95% CI]) was significantly improved in group G (71%) compared to group B (26%; [45 {36-55}]; P < .0001). Adequate depth rate (>38 mm) was significantly improved in group G (85%) compared to group B (43%; [42 {33-52}]; P < .0001). Adequate CC rate (90-120/min) was significantly improved in group G (81%) compared to group B (56%; [25 {15-35}]; P < .0001). The average CC rate and depth in group G were significantly less dispersed around the mean compared to group B (test of variance P < .007; P < .015 respectively). PRINCIPAL CONCLUSIONS: The use of the CPRmeter significantly improved CC quality performed by students inexperienced in cardiopulmonary resuscitation.

The influence of magnesium on morphine-induced stimulation of the reward system.

The present study was designed to assess the influence of magnesium (Mg) as MgCl(2) (10 or 40 mg/kg b.wt/day i.p.) and of its interaction with morphine on the reward system (RS) in Wistar rats. For this purpose, we evaluated conditioning place preference on a 12 day experiment schedule. Our data show that MgCl(2) (10 mg/kg b.wt/day) has moderate but significant effects on stimulating RS (increasing the time spent in associated conditioned compartment) (327.75 +/- 11 s in the Mg (10 mg/kg b.wt) group vs 295.2 +/- 8 s in the control (saline) group, p < 0.05) but not at higher Mg doses (40 mg/kg b.wt/day). We tested the influence of MgCl(2) (10 mg/kg b.wt./day i.p.) upon naloxone (2 mg/kg b.wt/ i.p.)-induced place aversion. Administrated alone, naloxone has an aversive effect on place preference. MgCl(2) (10 mg/kg b.wt/day i.p.) has a significantly decreased aversive effect of naloxone (280.7 +/- 37 s in naloxone + MgCl(2) (10 mg/kg b.wt) group vs 189 +/- 21 s in naloxone group, p < 0.05). MgCl(2) at both tested doses, added to morphine (3 mg/kg b.wt/day i.p), decreased the acquisition of morphine-induced place preference (262.2 +/- 17 s) in morphine + MgCl(2) (40 mg/kg b.wt) group vs 462.15 +/- 28 s in morphine group, p < 0.05). MgCl(2), 10 mg/kg b.wt/day i.p. decreased both morphine-induced place preference and naloxone-induced place aversion.

Magnesium and other bivalent cations influence upon sodium montelukast effect in experimental-induced thermoalgesia.

We tested the influence of magnesium, zinc and copper upon the montelukast (MK, antagonist of cysteinyl leukotriene receptor type 1) effect in experimentally-induced thermoalgesia. We worked on 5 groups of 10 adults, each Wistar rats, that received: group I-control; group II: MK (10 mg/kg) unique administration; group III: MgCl2 (1 mM/kg/day) i.p., 3 days and MK (10 mg/kg) unique administration on the 3rd day; group IV: ZnCl2, (0.1 mM/kg/day), i.p., 3 days and MK (10 mg/kg) unique administration on the 3rd day; group V: copper acetate (0.05 mM/kg/day), i.p., 3 days and MK (10 mg/kg) unique administration on the 3rd day. We determined the thermoalgesic sensitivity (TS) using a tail flick analgesia meter, initially, 3 days after daily cation administration and 3 hours after MK administration. Our data show that MK has a statistically significant reduction of TS vs control group (3.76 +/- 1.04 s vs 1.81 +/- 0.98 s, p < 0.05). Copper and magnesium administration do not significantly change the MK effect to decrease TS. The co-administration of zinc and MK statistically significantly increased the TS of the group that received only MK (2.51 +/- 0.21 s vs 3.76 +/- 1.04 s, p < 0.05). Animals that received only cations (in the above mentioned doses) did not significantly change TS.

Magnesium influence on morphine--induced pharmacodependence in rats.

We tested Mg2+ influence on experimental morphine-induced pharmacodependence in rats. Morphine-induced pharmacodependence model consists of progressively increased doses of morphine (M) (5 mg/kg i.p. until 90 mg/kg i.p.) during 10 days. Withdrawal syndrome was induced by naloxone (N) administration (1 mg/kg, s.c.) on the 11th day, 2 h after the last morphine administration. We evaluated and statistically interpreted symptoms from withdrawal syndrome. 2 groups received magnesium acetate (MgAc) 0.5 mEq/kg/day i.p. and 0.1 mEq/kg/day MgAc i.p. respectively during all 11 days of morphine-induced pharmacodependence. Serum magnesium levels were determined by spectrophotometry. Data obtained show that MgAc significantly decreases symptoms from withdrawal syndrome (grooming 19.9 +/- 2.1 in M + MgAc 0.5 mEq/kg/day vs. 33 +/- 2.85 in M group, p < 0.01).

Magnesium influence on nicotine pharmacodependence and smoking.

We followed the magnesium effect (Magne B(6)R, Sanofi-Synthelabo) with internal administration in 53 adult neurotic smoking patients (more than 10 cigarettes/day) of both genders admitted into psychiatric hospital. The nicotine dependence was assessed by the Fagerstrom test, initially and after 28 days of magnesium intake. Plasmatic magnesium level was determined before any therapy and at 28 days. All patients received benzodiazepines during the trial. Our data show that patients that received magnesium therapy showed a significant decrease in the number of cigarettes smoked and Fagerstrom test after 4 weeks [Fagerstrom score 7.93 +/- 0.17 before magnesium therapy versus 6.78 +/- 0.18 (P < 0.05) after 28 days of magnesium therapy]. In the group of smokers who did not receive magnesium, the Fagerstrom score did not change significantly [Fagerstrom score 7.48 +/- 0.22 initial versus 7.24 +/- 0.19 after 28 days]. Magnesium supplementation raised plasmatic levels (17.2 +/- 1.2 mg/L before versus 26.1 +/- 1.6 mg/L after 28 days of magnesium intake, P < 0.01). The results suggest that this cation might be a useful adjuvant in treatment of nicotine pharmacodependence.