Increased susceptibility to cardiovascular effects of dihydrocapcaicin in resuscitated rats. Cardiovascular effects of dihydrocapsaicin

<p>Abstract</p> <p>Background</p> <p>Survivors of a cardiac arrest often have persistent cardiovascular derangements following cardiopulmonary resuscitation including decreased cardiac output, arrhythmias and morphological myocardial damage. These cardiovascular derangements may lead to an increased susceptibility towards the external and internal environment of the cardiovascular system as compared to the healthy situation.</p> <p>Methods</p> <p>Here we tested the hypothesis that the cardiovascular system in healthy rats and rats resuscitated from a cardiac arrest may be differentially affected by a transient receptor potential vanilloid type 1 agonist, by continuous intravenous infusion of dihydrocapsaicin (DHC).</p> <p>Results</p> <p>Compared to baseline, infusion of DHC caused an initial increase in mean arterial blood pressure in both healthy and resuscitated rats of 25% and 10%, respectively. Also, we observed an initial response of tachycardia in both healthy and resuscitated rats of 30% and 20%, respectively. Then, at high levels of DHC infusion (> 2.0 mg/kg/hr) we observed two single episodes of transient bradycardia and hypotension in 33% of the healthy rats, which was consistent with a TRPV1 agonist induced Bezold-Jarisch reflex. In contrast, in resuscitated rats we observed multiple episodes of bradycardia/hypotension in 100% of the rats and at a dose of DHC of 0.65 mg/kg/hr. Notably, this DHC effect could be completely blocked in the resuscitated rats by pre-treatment with atropine, a muscarinic acetylcholine antagonist.</p> <p>Conclusions</p> <p>Our results indicate that the susceptibility of the rats towards TRPV1 agonist induced Bezold-Jarisch reflex is increased in those resuscitated from cardiac arrest compared to the healthy situation.</p

Effects of resuscitation with crystalloid fluids on cardiac function in patients with severe sepsis

<p>Abstract</p> <p>Background</p> <p>The use of hypertonic crystalloid solutions, including sodium chloride and bicarbonate, for treating severe sepsis has been much debated in previous investigations. We have investigated the effects of three crystalloid solutions on fluid resuscitation in severe sepsis patients with hypotension.</p> <p>Methods</p> <p>Ninety-four severe sepsis patients with hypotension were randomly assigned to three groups. The patients received the following injections within 15 min at initial treatment: Ns group (n = 32), 5 ml/kg normal saline; Hs group (n = 30), with 5 ml/kg 3.5% sodium chloride; and Sb group (n = 32), 5 ml/kg 5% sodium bicarbonate. Cardiac output (CO), systolic blood pressure, mean arterial pressure (MAP), body temperature, heart rate, respiratory rate and blood gases were measured.</p> <p>Results</p> <p>There were no differences among the three groups in CO, MAP, heart rate or respiratory rate during the 120 min trial or the 8 hour follow-up, and no significant differences in observed mortality rate after 28 days. However, improvement of MAP and CO started earlier in the Sb group than in the Ns and Hs groups. Sodium bicarbonate increased the base excess but did not alter blood pH, lactic acid or [HCO₃]^-values; and neither 3.5% hypertonic saline nor 5% sodium bicarbonate altered the Na⁺, K⁺, Ca²⁺or Cl^-levels.</p> <p>Conclusion</p> <p>All three crystalloid solutions may be used for initial volume loading in severe sepsis, and sodium bicarbonate confers a limited benefit on humans with severe sepsis.</p> <p>Trial registration</p> <p>ISRCTN36748319.</p

A body mass index related scale for reconstructive breast reduction

PURPOSE: Breast reduction is a highly emotional theme and bears conflicting interest groups: 1) women who are suffering from symptomatic macromastia and therefore would wish to have their breast reduction paid by the insurers, irrespective of the amount of resection weight, 2) the insurance companies, who are ready to cover only really medically indicated operations and due to a lack of objective parameters often apply the very strict, arbitrary criterium for a minimum resection weight of 500 g per breast and 3) the surgeons who try to provide a fair, scientific basis for the differentiation between cosmetic and reconstructive indications for breast reductions for the sake of both the patients and the insurance parties. Concerned about such a generalizing rule we undertook a retrospective review of our patients' charts with both, cosmetic and reconstructive indications to judge the available, more-level minimum resection weight standards and see wether they were appropriate to use, or to provide an objective and measurable guideline for a scaled amount of breast reduction beyond the 500 g-resection-rule, adapted to the individual woman's body proportions. METHODS: 136 women could be included in the study. The resection weight was recorded and correlated to various parameters of the body proportions such as weight, height, the body mass index (BMI) and the body surface. The results were compared to the available minimum resection weight rules. RESULTS: The resection weight ranged from 55 to 1530 g (mean 450 g +/- 266 g, median 406 g). Overweight was present in 36% of all patients, whereas obesity was present in 7.5% of women. The mean BMI was 25.1 kg/m2. Of the twenty-four patients (18%), who were classified a priori as having a cosmetic indication, 4 (18%) had more than 500 g breast tissue resected bilaterally. On the other hand, in 55% of reconstructive patients less than the predicted 500 g of breast tissue had been resected. From all examined parameters the BMI had the highest correlation to the resected mean breast tissue (r = 0.64, p = < 0.001). DISCUSSION: Our retrospective review thus showed that with an arbitrary 500 g breast resection-rule all women beyond the mean values for weight and height were clearly put at a disadvantage. Also not completely solving this problem are the already available, more objective guidelines for graded minimum resection weight recommendations, which have relied on the body weight or the body surface area, parameters that both had a much lower correlation to the resected breast tissue in the patient group than the BMI. We therefore suggest using the BMI as the basis for a graded, more-level weight resection standard for reconstructive breast reductions. This algorithm is related solely to objectifying data and thus avoids biases from empirically derived data or hardly quantifiable breast (or obesity)-related pain syndromes, and respects all the different body builds of women