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Biomedical subjects

N Nathan

Publications and source records attributed to N Nathan.

At least 55 records · Page 3Linked to original sources
PubMed1996

Short-term follow up of patients with multibacillary leprosy and HIV infection.

During a period of 9 years, four male patients with HIV and Hansen's disease were detected in Tamil Nadu, South India. The sequence as to which infection came first is not known. All had high-risk sexual behavior with commercial sex workers and a past history of genital ulcer disease. Their spectrum of leprosy was multibacillary. Patient no. 1 had pure neural leprosy of the lepromatous type, which is rare. He also had a single episode of type 1 reaction which did not require steroid therapy. Despite having taken inadequate treatment, patient no. 2 remained clinically and bacteriologically quiescent after 4 years of follow up. He had a low CD4 count of 330 cells/mm3. The third patient completed a full course of multibacillary multidrug therapy, and a year later is clinically and bacteriologically inactive. The fourth patient died of AIDS within 2 months of the dual diagnosis.

Adult↗
PubMed1996

Potentiation of atracurium by pancuronium during propofol-fentanyl-N2O anesthesia.

At the end of abdominal surgery deep neuromuscular blockade is required for peritoneal closure. Ideally injecting an intermediate acting drug like atracurium after a long acting drug such as pancuronium should deepen the neuromuscular block without the fear of an inadequate reversal at the completion of surgery. Thirty patients ASA I or II status, without known allergy to myorelaxant and without neuromuscular, hepatic or renal failure were included in this study. Anesthesia was induced and maintained with propofol, fentanyl, and N20. Normal core temperature was maintained by active warming of the upper part of the body. Blood electrolytes and the acid-base status were within the normal range. The accelerographic responses to Train-Of-Four supramaximal stimulation (TOF) of the ulnar nerve was monitored at the thumb. After obtaining a stable response with the accelerograph, the patients randomly received pancuronium (0.10 mg.kg-1, group I, n = 10 and group II, n = 10) or atracurium (0.50 mg.kg-1, group III, n = 10). An additional dose of atracurium (0.16 mg.kg-1, group I and III) or pancuronium (0.03 mg.kg-1, group II) was injected when the first response of TOF stimulation (T1) reached 25% of its initial value. Then the time to obtain a 25% twitch height of T1 (T25), the recovery index (RI 25-75), the delay to obtain 4 responses to TOF and an adequate recovery [TOF ratio of 0.70 (TOF70)] were monitored. Injection of 60% ED95 of atracurium after pancuronium resulted in a similar recovery of neuromuscular function as after 45% ED95 of pancuronium as shown by the same recovery of T25 (66.5 +/- 4.2 min versus 71.4 +/- 7.8 min, group I versus group II, p > 0.05) and TOF70 (131.6 +/- 15.7 min versus 144.0 +/- 17.5, group I versus II, p > 0.05). Nevertheless the RI 25-75 of group I was of intermediate duration between those of group II and III. Electrolytes and acid-base status were similar between groups at the beginning of surgery. Thus this study shows a synergistic effect of the combination of atracurium after pancuronium occurring in non hypothermic patients anesthetized without halogenated agents. Because the duration of action of the drug administered first governs the duration of action of the subsequent neuromuscular myorelaxant, the neuromuscular function should be closely monitored at the end of surgery if neuromuscular drugs are used in combination.

Anesthetics, Inhalation↗
PubMed1996

[Caudal and spinal anesthesia in sub-umbilical surgery in children. Apropos of 1875 cases].

Caudal and spinal anaesthesia are two techniques widely used in European children. The aim of this retrospective study was to evaluate the applicability of this practice in developing countries. The study concerned 1875 children, 1 day to 17 years old. isobaric 0.5% bupivacaine was used for spinal anaesthesia (n = 730) and mixture a of 1% lidocaine-0.25% bupivacaine with epinephrine 1/200,000 for caudal anaesthesia (n = 1,145). Spinal anaesthesia was performed in neonates and infants (< 3 years) and caudal anaesthesia in children (aged 14 days to 17 years) undergoing urological and lower extremity surgery. No variation of heart rate, blood pressure or blood oxygen saturation (SpO2) were observed during surgery. Failure of the technique was less than 1%. These two regional anaesthesia techniques are easy to perform and are inexpensive. This is advantageous for developing countries.

Adolescent↗
PubMed1995

[Intra-arterial thrombolysis of acute mesenteric ischemia].

A 73-year-old man with pre-existing cardiac failure, coronary artery and chronic obstructive pulmonary disease was presented for an acute mesenteric ischaemia, resulting from an embolic obstruction of the superior mesenteric artery. An intra-arterial fibrinolysis with a bolus of 250 000 units of streptokinase, followed by an infusion of 150 mg rtPA with adequate heparin dosage was performed 10 hours after the first symptoms. An abdominal guarding occurred 24 hours later, despite radiological improvement, justifying emergency surgery which confirmed the partial efficiency of the medical therapy. Unfortunately, a cardiogenic shock occurred preoperatively and the patient died five days later from intractable cardiovascular failure.

Acute Disease↗
PubMed1995

[Measurement of tympanic temperature by infrared and thermocouple thermometry. A comparative study].

OBJECTIVE: To compare tympanic temperatures obtained with an infrared thermometer Core Check 2090A (IVAC), non in contact with the tympanic membrane, to values obtained with a thermocouple thermometer Mon-A-Therm (Mallinckrodt) in contact with it, and to assess whether the differences depend on the person measuring the temperature. STUDY DESIGN: Prospective comparative open study. PATIENTS: The study included 150 adults in whom the tympanic temperatures were measured at their admission to recovery room by 10 nurse anaesthetists. METHODS: Each thermometer was inserted in the same patient into an external acoustic meatus. The median and range of the temperature differences were used to assess the bias and the accuracy of the measures. Their reliability was analyzed with consideration of the measuring person and the presence of irrelevant values, defined as a temperature difference over 0.3 degrees C. RESULTS: The temperatures obtained with both devices were similar (36.2 +/- 0.7 degrees C with IVAC thermometer vs 36.2 +/- 0.8 degrees C with Mallinckrodt thermometer). The median value of the differences was 0 degrees C, with a range of 2.5 degrees C (maximum value + 1.5 degrees C, minimum value: -1 degree C). Nineteen patients could be qualified as hypothermic (temperature < 36.5 degrees C) with one thermometer and normothermic (temperature > or = 36.5 degrees C) with the other. Among them, only 9 (6%) had temperature differences above 0.3 degrees C. The temperature differences were not different according to the measuring nurse. Nevertheless two of them obtained major differences or irrelevant figures. CONCLUSIONS: As compared to the thermocouple thermometry, infrared thermometry has no bias but a low precision. The measurement error does not allow the recognition of hypothermia in 6% of patients. The error may be made by the measuring person and/or related to the anatomy and the patency of the external acoustic meatus. Tympanic infrared thermometry seems to be a convenient method for temperature measurements at short time intervals in the recovery room, provided its limitations are kept in mind.

Adult↗
PubMed1995

Effects of a paf-receptor antagonist on hemodynamics during and after cardiopulmonary bypass.

OBJECTIVES: To assess after cardiopulmonary bypass (CPB) the role of paf-acether (paf), a phospholipid mediator whose injection in animal mimics the hemodynamics observed after CPB. DESIGN: Prospective double-blind randomized study. SETTING: Single institutional university hospital. PARTICIPANTS: 18 patients scheduled to undergo coronary artery bypass graft. INTERVENTIONS: 18 patients randomly received a placebo (n = 8) or 120 mg BN52021 (n = 10), a paf-receptor antagonist injected twice just before vascular cannulation and before cross-clamp release. MEASUREMENTS AND MAIN RESULTS: Hemodynamic measurements were performed with a pulmonary artery and a radial artery catheter before and after the first injection of BN52021 or placebo, at the end of CPB, 1, 15, and 30 minutes after protamine infusion, then 6 hours and 24 hours postoperatively. BN52021 infusion, did not affect hemodynamic parameters. After CPB, the pulmonary artery pressures, the cardiac index, and the pulmonary artery occlusion pressures were statistically the same between groups. By contrast, the pulmonary vascular resistances (1.5 +/- 0.5 IU v 4.5 +/- 0.6 IU, p < 0.05), the right ventricular systolic work index (5.3 +/- 0.91 g m m-2 v 9.37 +/- 1.02 g m m-2, p < 0.05) and the transpulmonary gradient (4.7 +/- 1.1 mmHg v 12.0 +/- 1.2 mmHg, p < 0.05) were lower in the BN52021 group as compared with the placebo group. After protamine infusion, these differences between groups disappeared. CONCLUSION: Because the inotropic and vasodilator therapy and the volume loading were the same between groups, this study suggests that pretreatment with a paf-receptor antagonist improves post-CPB pulmonary resistance. Nevertheless, this beneficial effect is transient without consequences on left ventricular function indices.

Blood Pressure↗
PubMed1995

[Pharmacokinetics of lidocaine and bupivacaine after peribulbar block with additional hyaluronidase].

OBJECTIVE: To assess the time course of plasma concentrations of lidocaine and bupivacaine associated with hyaluronidase for peribulbar block. STUDY DESIGN: Prospective study. PATIENTS: Ten patients (mean age = 71 +/- 11 yrs, mean weight 63 +/- 10 kg) scheduled for cataract surgery with lens implantation. METHOD: Lidocaine 2% (5.5 mL = 110 mg) and bupivacaine 0.5% (5.5 mL = 27.5 mg) associated with hyaluronidase (80 IU) were injected supra and infra-orbitally, in patients premedicated with midazolam. Blood samples wer0 collected at constant time intervals from the end of infiltration until the 6th hour. The plasma concentrations of local anesthetics were measured with the HPLC technique. RESULTS: The median plasma peak concentration was 1.74 mg.L-1 after 10 min for lidocaine, and 0.52 mg.L-1 after 7.5 min for bupivacaine respectively. CONCLUSIONS: The similar delays of occurrence of peak concentrations confirm that liposolubility is not the only factor of diffusion of local anaesthetics from the periocular fat into the blood stream. The peak concentrations are far below the alleged toxic concentrations. When associated with hyaluronidase, the peak concentrations occur as rapidly as after endotracheal or paracervical administration.

Aged↗
PubMed1994

[Use of Diprivan in renal insufficiency].

The use of propofol for induction and maintenance of anaesthesia in end-stage chronic renal failure has been reported in many publications. The rather minor pharmacokinetic changes of propofol recorded in patients with end-stage chronic renal failure are in favour of the absence of accumulation of agent, and is a good reason for its use in this context. Acute variations in potassium plasma concentrations or acid-base balance have been observed neither in healthy subjects nor in end-stage chronic renal failure, after administration of propofol. Effects of propofol on known impaired renal function have not been studied, apart from renal transplantation. Therefore, postoperative monitoring of renal function is essential, as haemodynamic variations elicited by the administration of propofol contribute to its aggravation. These haemodynamic variations depend on the dose, the rate of administration, the underlying cardiovascular condition and the blood volume of the patient. Due to inter-patient variability in clinical and laboratory parameters, the dose required for a stable anaesthesia varies with the each patient. Careful, slow administration ensures easier titration of the required dose, keeping any secondary haemodynamic side-effects to a minimum. In these patients the quality and speed of recovery depends on the type and dose of agents associated with propofol to maintain anaesthesia. Nitrous oxide, in reducing the need for opioids, should shorten the recovery period. Monitoring of cyclosporine blood concentrations after anaesthesia using propofol is mandatory in renal transplant patients.

Anesthesia, Intravenous↗
PubMed1994

Effects of the platelet-activating factor receptor antagonist BN 52021 on hematologic variables and blood loss during and after cardiopulmonary bypass.

Cardiopulmonary bypass (CPB)-induced thrombocytopenia and leukopenia is augmented after heparin reversal of protamine. Platelet-activating factor (PAF) might be implicated in these disorders. To evaluate the effects of PAF on the hematologic disorders and blood loss during and after CPB, patients were pretreated with BN 52021, a PAF receptor antagonist, or a placebo. BN 52021 (120 mg) (n = 13) or placebo (n = 15) were infused intravenously before vascular cannulation and before cross-clamp release. Platelet and leukocyte counts were assessed in venous blood before and after the first dose of BN 52021 or placebo, 2 min after the beginning of CPB (at the entry of the oxygenator), at the end of CPB, 1, 15, and 30 min after protamine infusion, and 6 and 24 h after CPB. The decrease in platelet and leukocyte counts were the same between groups during and after CPB and after protamine infusion. Bleeding times were not modified by the pretreatment of patients with BN 52021. During surgery, blood loss reached 1660 +/- 297 mL in the BN 52021 group and 1599 +/- 283 mL in the placebo group (P > 0.05). Forty-eight hours postoperatively, the chest tube outputs were not different between groups (1460 +/- 418 mL vs 1640 +/- 362 mL in the BN 52021 and placebo groups, respectively). This study shows that BN 52021 infusion did not change the hematologic variables studied. Moreover, a PAF antagonist pretreatment did not protect the patients against CPB- or protamine-induced hematologic changes.

Analysis of Variance↗
PubMed1993

[Infusion of propofol or closed-circuit isoflurane. A study of cost].

The choice of an anaesthetic agent is influenced by its cost. The use of a circle absorber system decreases the cost of the maintenance of anaesthesia with halogenated agents. Fast recovery and low incidence of postoperative nausea and vomiting are the main advantages of propofol. The cost of propofol can limit its use for the maintenance of anaesthesia except for short procedures. This prospective study compared in 50 ASA 1 and 2 patients the cost of anaesthesia with either propofol (group P, n = 25) or the association thiopentone-isoflurane administered with a rebreathing circuit (group I, n = 25). Patients were premedicated the evening before surgery with 2.5 mg lorazepam. Anaesthesia was induced with either propofol (2-3 mg.kg-1) or thiopentone (4-6 mg.kg-1) and maintained with either propofol (6-10 mg.kg-1.h-1) in group P or isoflurane continuously injected as liquid in the expiratory limb of the circuit in group I. The side effects of anaesthesia and the delay of recovery and discharge from the recovery room were assessed. Peroperative cost of anaesthesia included nitrous oxide, isoflurane and i.v. agents, fluids volumes and disposable devices. The total cost of anaesthesia included also the recovery room stay. The mean duration of anaesthesia was not significantly different between the two groups (109.4 +/- 7.1 min vs 107.3 +/- 7.3 min group P vs group I). The delay lf recovery (eyes opening) was shorter in the propofol group (14.4 +/- 1.3 min vs 19.4 +/- 1.4 min) as well as the delay of discharge from the recovery room (70 +/- 4 min, vs 82.4 +/- 4.6 min).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗