Effect of Waters Enriched in O2 by Injection or Electrolysis on Performance and the Cardiopulmonary and Acid-Base Response to High Intensity Exercise.

Several brands of water enriched with O2 (O2-waters) are commercially available and are advertised as wellness and fitness waters with claims of physiological and psychological benefits, including improvement in exercise performance. However, these claims are based, at best, on anecdotal evidence or on a limited number of unreliable studies. The purpose of this double-blind randomized study was to compare the effect of two O2-waters (~110 mg O2·L-1) and a placebo (10 mg O2·L-1, i.e., close to the value at sea level, 9-12 mg O2·L-1) on the cardiopulmonary responses and on performance during high-intensity exercise. One of the two O2-waters and the placebo were prepared by injection of O2. The other O2-water was enriched by an electrolytic process. Twenty male subjects were randomly allocated to drink one of the three waters in a crossover study (2 L·day-1 × 2 days and 15 mL·kg-1 90 min before exercise). During each exercise trial, the subjects exercised at 95.9 ± 4.7% of maximal workload to volitional fatigue. Exercise time to exhaustion and the cardiopulmonary responses, arterial lactate concentration and pH were measured. Oxidative damage to proteins, lipids and DNA in blood was assessed at rest before exercise. Time to exhaustion (one-way ANOVA) and the responses to exercise (two-way ANOVA [Time; Waters] with repeated measurements) were not significantly different among the three waters. There was only a trend (p = 0.060) for a reduction in the time constant of the rapid component of VO2 kinetics with the water enriched in O2 by electrolysis. No difference in oxidative damage in blood was observed between the three waters. These results suggest that O2-water does not speed up cardiopulmonary response to exercise, does not increase performance and does not trigger oxidative stress measured at rest.

Incidence of akathisia after postoperative nausea and vomiting prophylaxis with droperidol and ondansetron in outpatient surgery: A multicentre controlled randomised trial.

BACKGROUND: Akathisia, a distressing movement disorder induced by butyrophenones, has been described with low doses of droperidol used for postoperative nausea and vomiting (PONV) prophylaxis, but the incidence remains unclear. OBJECTIVES: To determine the incidence of akathisia after PONV prophylaxis with two doses of droperidol in comparison with ondansetron, in patients undergoing ambulatory surgery. We hypothesised that the incidence of akathisia is higher with droperidol than that with ondansetron. DESIGN: Randomised controlled double blind trial. SETTING: Two University Hospital Centres and two private Clinics from January to September 2014. PATIENTS: Patients (n=297) undergoing general anaesthesia for ambulatory surgery were randomly allocated to receive PONV prophylaxis with droperidol (0.625 or 1.25 mg) or ondansetron 4 mg; patients of the three groups also received 4 mg of dexamethasone. Exclusion criteria were contraindication to droperidol and ondansetron, use of psychotropic medications or benzodiazepines or history of psychotic illness. INTERVENTIONS: Participants received droperidol (0.625 or 1.25 mg) or ondansetron 4 mg during general anaesthesia. After discharge from the postanaesthesia care unit presence and severity of akathisia were assessed using the Barnes Akathisia Rating Scale at 4 h postoperatively. MAIN OUTCOME MEASURES: Score of the Global Clinical Assessment of Akathisia of Barnes Akathisia Rating Scale. RESULTS: The number of akathisia observed was 1/118 (0.8%) in the ondansetron group, 1/84 (1.2%) in droperidol 0.625 mg group, and 3/87 (3.4%) in droperidol 1.25 mg group. The akathisia rate difference among the three groups was not significant (P = 0.52). We could not demonstrate significant differences in the incidence of akathisia between the two doses of droperidol. The only case of marked akathisia treated with benzodiazepines was observed after droperidol 1.25 mg. CONCLUSION: The use of droperidol or ondansetron for PONV prophylaxis is associated to a low incidence of akathisia (0.8 to 3.4%) after general anaesthesia for ambulatory surgery. TRIAL REGISTRATION: Clinicaltrials.gov: NCT01942343.

Apparent Km of mitochondria for oxygen computed from Vmax measured in permeabilized muscle fibers is lower in water enriched in oxygen by electrolysis than injection.

BACKGROUND: It has been suggested that oxygen (O2) diffusion could be favored in water enriched in O2 by a new electrolytic process because of O2 trapping in water superstructures (clathrates), which could reduce the local pressure/content relationships for O2 and facilitate O2 diffusion along PO2 gradients. MATERIALS AND METHODS: Mitochondrial respiration was compared in situ in saponin-skinned fibers isolated from the soleus muscles of Wistar rats, in solution enriched in O2 by injection or the electrolytic process 1) at an O2 concentration decreasing from 240 µmol/L to 10 µmol/L (132 mmHg to 5 mmHg), with glutamate-malate or N, N, N', N'-tetramethyl-p-phenylenediamine dihydrochloride (TMPD)-ascorbate (with antimycin A) as substrates; and 2) at increasing adenosine diphosphate (ADP) concentration with glutamate-malate as substrate. RESULTS: As expected, maximal respiration decreased with O2 concentration and, when compared to glutamate-malate, the apparent Km O2 of mitochondria for O2 was significantly lower with TMPD-ascorbate with both waters. However, when compared to the water enriched in O2 by injection, the Km O2 was significantly lower with both electron donors in water enriched in O2 by electrolysis. This was not associated with any increase in the sensitivity of mitochondria to ADP; no significant difference was observed for the Km ADP between the two waters. CONCLUSION: In this experiment, a higher affinity of the mitochondria for O2 was observed in water enriched in O2 by electrolysis than by injection. This observation is consistent with the hypothesis that O2 diffusion can be facilitated in water enriched in O2 by the electrolytic process.

Effect of administration of water enriched in O2 by injection or electrolysis on transcutaneous oxygen pressure in anesthetized pigs.

BACKGROUND: Oral administration of oxygenated water has been shown to improve blood oxygenation and could be an alternate way for oxygen (O2) supply. In this experiment, tissue oxygenation was compared in anesthetized pigs receiving a placebo or water enriched in O2 by injection or a new electrolytic process. METHODS: Forty-two pigs randomized in three groups received either mineral water as placebo or water enriched in O2 by injection or the electrolytic process (10 mL/kg in the stomach). Hemodynamic parameters, partial pressure of oxygen in the arterial blood (PaO2), skin blood flow, and tissue oxygenation (transcutaneous oxygen pressure, or TcPO2) were monitored during 90 minutes of general anesthesia. Absorption and tissue distribution of the three waters administered were assessed using dilution of deuterium oxide. RESULTS: Mean arterial pressure, heart rate, PaO2, arteriovenous oxygen difference, and water absorption from the gut were not significantly different among the three groups. The deuterium to protium ratio was also similar in the plasma, skin, and muscle at the end of the protocol. Skin blood flow decreased in the three groups. TcPO2 slowly decreased over the last 60 minutes of the experiment in the three groups, but when compared to the control group, the values remained significantly higher in animals that received the water enriched in O2 by electrolysis. CONCLUSIONS: In this protocol, water enriched in O2 by electrolysis lessened the decline of peripheral tissue oxygenation. This observation is compatible with the claim that the electrolytic process generates water clathrates which trap O2 and facilitate O2 diffusion along pressure gradients. Potential applications of O2-enriched water include an alternate method of oxygen supply.