Biomedical subjects
M R Sury
Publications and source records attributed to M R Sury.
Cardiovascular actions of trimetaphan nitroprusside. Comparison with sodium nitroprusside in greyhounds.
Trimetaphan nitroprusside (TNP) is a new potent hypotensive agent developed to induce and maintain decreases in arterial pressure unaccompanied by resistance. This study investigated its properties and compared them with those of sodium nitroprusside (SNP) in anaesthetized greyhounds. The mean dose response to TNP was obtained by measuring haemodynamic changes in five dogs. With increasing doses, stepwise decreases in mean arterial pressure and progressive increases in heart rate occurred: cardiac index did not change significantly. In a further six greyhounds, SNP and TNP were alternately infused to induce and maintain a 30% reduction in arterial pressure for 30 min. Both drugs were short-acting, decreased systemic vascular resistance and caused tachycardia. Infusion of TNP produced lower plasma and red cell cyanide concentrations; SNP maintained hypotension with significantly less tachycardia. We conclude that there was no outstanding advantage of TNP over SNP when given as a short-term infusion in greyhounds.
Nalbuphine combined with midazolam for outpatient sedation. An assessment of safety in volunteers.
Eighteen healthy volunteers were studied in a double-blind trial to determine which dose of nalbuphine (0.05, 0.1 or 0.2 mg/kg) may be combined with midazolam 0.05 mg/kg to provide a safe outpatient intravenous sedative technique. The ventilatory response to carbon dioxide and end tidal PCO2 were measured before and after the drugs were administered. A mild degree of respiratory depression occurred, which was maximal at 3-30 minutes after injection. This was not related to dose except that nalbuphine 0.05 mg/kg resulted in the slowest respiratory rates. The implications of these findings for clinical practice are discussed.
Nalbuphine combined with midazolam for outpatient sedation. An assessment in fibreoptic bronchoscopy patients.
Forty patients who required day case fibreoptic bronchoscopy were sedated with either nalbuphine 0.2 mg/kg and midazolam 0.05 mg/kg (n = 20), or midazolam 0.05 mg/kg alone (n = 20). Extra midazolam was administered when required. The degree of respiratory depression measured by arterialised venous carbon dioxide levels was recorded together with heart rate, arterial blood pressure, respiratory rate and sedation score, before administration of the drugs and at regular intervals thereafter. Patients who received nalbuphine had slightly higher carbon dioxide levels but respiratory rate and cardiovascular changes were similar in both groups. The addition of nalbuphine to midazolam improves the quality of sedation but prolongs the recovery time and increases the incidence of side effects.
Plasma levels of neuropeptide tyrosine Y (NPY) are increased in human sepsis but are unchanged during canine endotoxin shock despite raised catecholamine concentrations.
Alterations in levels of adrenal vein and circulating immunoreactive neuropeptide tyrosine Y (NPY), as well as systemic catecholamine concentrations, have been investigated in the dog after endotoxin administration. Eighteen dogs were anaesthetized with alpha-chloralose and allowed to breathe spontaneously. Severe shock was produced by the administration of a large bolus of Escherichia coli endotoxin followed by a continuous infusion. In two further animals the left lumbar adrenal vein was cannulated and an intermittent choke allowed retrograde sampling of the adrenal effluent. The production of hypodynamic shock was associated with marked increases in systemic catecholamine concentrations but there were no consistent changes in adrenal vein or systemic immunoreactive NPY levels. In contrast, circulating concentrations of immunoreactive NPY were markedly raised above the normal range in five patients with septic shock.
Accidental disconnexion following inactivation of Servoventilator alarm.
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Accidental spinal anaesthesia following intrathoracic intercostal nerve blockade. A case report.
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Dental bacteremia in children.
Bacteremia resulting from dental extraction is regarded as an important cause of bacterial endocarditis, and it is therefore recommended that patients undergoing tooth extraction be given prophylactic antibiotics. As dental procedures other than extractions may also cause bacteremias, we studied a variety of dental procedures routinely used in pediatric dentistry. Blood samples for cultures were obtained 30 s after each of 13 dental operative procedures in 735 anesthetized children aged 2-16 years. Four procedures used for conservative dentistry caused bacteremias significantly more often than the baseline value of 9.4%: polishing teeth 24.5%, intraligamental injection 96.6%, rubber dam placement 29.4%, and matrix band with wedge placement 32.1%. In comparison, toothbrushing alone caused a bacteremia on 38.5% of occasions. The organisms isolated were typical of odontogenic bacteremias in that 50% of the isolates were identified as varieties of viridans streptococci. These data show that a wider variety of dental procedures than was previously documented cause bacteremia.