Sodium pyruvate is better than sodium chloride as a resuscitation solution in a rodent model of profound hemorrhagic shock.

Pyruvate is an energy substrate that has both inotropic and antioxidant properties. In this study, we tested the hypothesis that survivorship would be better after resuscitation with 1.7% sodium pyruvate than 0.9% sodium chloride in a profound hemorrhagic shock model. The study was performed in a blinded manner. Rats were randomly assigned into two groups (ten in each group), a sodium chloride resuscitation group and a sodium pyruvate resuscitation group. After a 60-min shock period, we infused 80 ml/kg of a resuscitation solution. We continuously monitored mean arterial pressure and heart rate for 50 min after resuscitation. We recognized death by the disappearance of blood pressure pulsation and precordial movement. We performed a comparison of survivorship at 50 min post resuscitation using a Z-test of proportions. Nine (90%) of the animals that received sodium pyruvate were living 50 min after resuscitation, whereas only three (30%) of the animals that received sodium chloride survived to the same time point. We conclude that sodium pyruvate is better than sodium chloride as a resuscitation solution in a model of profound hemorrhagic shock.

Nitric oxide reduces pressor responsiveness during ovine hypoadrenocorticism.

1. Hypoadrenocorticism frequently results in critical hypotension, hypovolaemia, hyponatraemia and hyperkalaemia. Perhaps even more important, hypoadrenocorticoid humans experience decreased vasoconstriction in response to exogenous administration of vasoconstrictors, such as noradrenaline. 2. We studied chronically adrenalectomized adult sheep to test the hypothesis that the reduction in pressor responsiveness is the result of increased production of nitric oxide (NO) during hypoadrenocorticism. 3. Withdrawal of steroid replacement resulted in reduced blood pressure, reduced pressor responsiveness, as well as hyperkalaemia and hyponatraemia. 4. Inhibition of NO production by NG-nitro-L-arginine methyl ester in the hypoadrenocorticoid ewes restored mean arterial pressure and pressor responsiveness response to normal values. 5. The results of these experiments support the hypothesis that reduced pressor responsiveness in the hypoadrenocorticoid state is mediated by the overproduction of NO.

Evaluation and treatment of hypertension in active individuals.

Hypertension is a very common vascular disease. It is seen in adolescents, obese persons, postmenopausal women, and the elderly. A nonpharmacologic approach to treatment is a critical first step in management. The modalities include a diet low in salt and saturated fat, exercise, less than 2 ounces of alcohol daily, and abstinence from smoking. Dynamic (aerobic) exercise is effective in lowering blood pressure (BP) only if performed regularly. Weight reduction by diet must be combined with exercise if there is to be a reduction in BP. Strength training is not to be considered as an alternative to aerobic training for reducing BP. Antihypertensive mediation can be added to nonpharmacologic interventions for additional BP reduction. Beta-blockade is not a contraindication to exercise training.