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Biomedical subjects

Y Gozal

Publications and source records attributed to Y Gozal.

At least 19 recordsLinked to original sources
PubMed1998

ST segment changes following retinal surgery.

STUDY OBJECTIVE: To describe the perioperative cardiac morbidity in adult patients undergoing retinal surgery using continuous Holter monitoring. DESIGN: Prospective study. SETTING: University hospital. PATIENTS: 56 patients scheduled for elective retinal surgery with local anesthesia. INTERVENTIONS: Patients were monitored continuously for 24 hours using a Holter recorder. Blood samples for creatine phosphokinase (CPK) and serum myocardial creatine phosphokinase (CPK-MB) were taken preoperatively and 24 hours postoperatively. The characteristics of myocardial ischemia were compared according to the number of risk factors for ischemic heart disease. MEASUREMENTS AND MAIN RESULTS: The overall incidence of perioperative myocardial ischemia was high: 26.7% (n = 15). These patients exhibited 41 episodes of ischemia with mean ST segment change from baseline of 2.2+/-0.7 mm. However, almost all (93.3%) ischemic episodes were silent. Patients with two risk factors or more had 77% more episodes of ischemia than patients with one risk factor (p < 0.005), and the duration of ischemia was 47+/-22.5 minutes compared with 34.8+/-27.5 minutes (p = NS). The first episode of ischemia occurred an average of 10 hours after surgery. No patient had intraoperative evidence of ischemia. Half of the ischemic episodes were associated with an increase in heart rate. No patient had evidence of acute myocardial infarction. CONCLUSION: Retinal surgery with local anesthesia is accompanied by a high incidence of postoperative myocardial ischemia. No negative outcome was correlated to the occurrence of postoperative myocardial ischemia. The significance of these findings has yet to be evaluated.

Aged↗
PubMed1997

Halothane prevents postischemic production of hydroxyl radicals in the canine heart.

BACKGROUND: Recent studies indicate that during regional myocardial ischemia and subsequent reperfusion, volatile anesthetics may provide protection against free radical-related injury. The effect of halothane on free radical production during ischemia and reperfusion, in the canine heart, was investigated. The level of hydroxyl radical (.OH)-mediated conversion of salicylate to its dehydroxybenzoate derivatives (2,3-DHBA and 2,5-DHBA) was monitored. METHODS: Under general anesthesia, the heart was exposed through median sternotomy. Salicylate (100 mg/kg given intravenously) was administered 30 min before left anterior descending artery occlusion. Six dogs were studied using inhaled halothane (1.6%) 10 min before and during the 10-min ischemic period, followed by 50 min of reperfusion, and then they were compared with seven other dogs used as controls. Blood concentrations of salicylate, 2,3-DHBA and 2,5-DHBA, K+, lactate, oxygen content, and pH were monitored. RESULTS: An acute increase in the normalized concentrations of 2,3-DHBA and 2,5-DHBA was observed in the control animals during reperfusion. In contrast, halothane inhalation completely inhibited the production of both metabolites (P < 0.02), but 2,5-DHBA concentrations in the halothane-treated group were even less than the basal level (P < 0.05). The increase in lactate concentrations in the experimental animals was significantly less than that of controls (P < 0.05) and followed the same time-dependent pattern as the changes in K+ and pH. Halothane significantly decreased (P < 0.0001) the difference in oxygen content between coronary sinus and aortic root blood, suggesting decreased oxygen utilization during reperfusion. CONCLUSIONS: Halothane completely inhibited the production of .OH, and its administration may protect the heart from the deleterious effect of oxygen-derived reactive species, with attenuation of the metabolic response to ischemia.

Anesthetics, Inhalation↗
PubMed1996

Normothermic continuous blood cardioplegia improves electrophysiologic recovery after open heart surgery.

BACKGROUND: Myocardial protection during open heart surgery is based on administration of oxygenated blood cardioplegia, the preferred temperature of which is still under debate. The current randomized study was designed to prospectively evaluate the quality of myocardial protection and the functional recovery of the heart with either normothermic (group N) or hypothermic (group H) oxygenated blood cardioplegia. METHODS: Under continuous electrocardiographic Holter monitoring, 42 patients were randomly scheduled to receive either normothermic (33.5 degrees C) or hypothermic (10 degrees C) cardioplegia solutions during coronary bypass grafting surgery. Blood samples for creatinine phosphokinase, creatinine phosphokinase-MB, lactate, epinephrine, and norepinephrine were withdrawn during cardiopulmonary bypass via a coronary sinus cannula. RESULTS: Active cooling in group H on initiation of cardiopulmonary bypass was characterized by transition through ventricular fibrillation in 75% of patients, whereas in group N atrial fibrillation occurred in 65% of patients. On myocardial reperfusion, sinus rhythm spontaneously resumed in 95% of group N patients compared to 25% in group H (P = 0.0003). In the latter, 75% of patients developed ventricular fibrillation often followed by complete atrioventricular block, which necessitated temporary pacing for a mean duration of 168 +/- 32 min. Both groups showed a similar incidence of intraventricular block and ST segment changes. However, the incidence of ventricular premature beats in the first 16 h after cardiopulmonary bypass was significantly greater in group H (P < 0.05), 20 +/- 26/h, compared to 3 +/- 5/h in group N. Blood concentrations of lactate, creatinine phosphokinase, epinephrine, and norepinephrine increased gradually during the operation, but the differences between the groups were not significant. CONCLUSIONS: The current prospective human study suggests that the increased susceptibility for ventricular fibrillation and dysrhythmia, and the delayed recovery of the conduction system after hypothermic myocardial protection, are related to temperature-induced changes in vital cellular functions of the conduction tissue in the postischemic period. Both cardioplegic methods provide adequate myocardial protection but normothermic oxygenated blood cardioplegia may accelerate recovery of the heart after cardiopulmonary bypass.

Adult↗
PubMed1996

[Anesthetic problems of epidermolysis bullosa dystrophica. Apropos of a case].

Epidermolysis bullosa is a group of hereditary diseases of the skin that may also involve mucous membranes, particularly of the oropharynx and oesophagus. The common primary feature is the formation of blisters following even trivial trauma. During the management of anaesthesia, it is critical that trauma to the skin and mucous membranes be avoided or minimized in these patients. We report the case of a 3-year-old child who had two surgeries and discuss the anaesthetic implications of this disease.

Anesthesia, General↗
PubMed1995

Luke warm blood cardioplegia for CAB surgery in patients with severely impaired LV function. Improved results.

Ward blood cardioplegia (WBC) has recently been reported to improve myocardial protection in adult open heart surgery, especially in high risk cases. However, WBC has been reported to have some disadvantages including narrow safety margins concerning brain and kidney perfusion. We therefore modified our technique to utilize luke-warm blood cardioplegia (LWBC). We carried out 470 open heart procedures using luke-warm cardioplegia (anterograde + retrograde perfusion) from 1/2/1991 - 30/9/1992; 94 had LVEF < 30% and form the basis of this study. Other major risk factors in this group included: > 70 yrs - 26 patients, L main > 50% - 14 patients, emergencies - 11 patients, redo's - 3 patients. Eightyone patients underwent CAB only; 3 had additional MVR, 3 additional closure acute VSD of whom one underwent additional LV aneurysmectomy, one additional AVR; 4 patients underwent AVR only, and 2 MVR. Average number of grafts/patient for the 81 isolated CAB's was 4.5. IABP was necessary postbypass in 4 patients (9 emergencies were on IABP support at time of operation). Thirty day mortality was 3 patients (3.2%). Late mortality was 5 cases. These results are superior to those achieved using cold protection and warm blood cardioplegia. LWBC is a safe method for myocardial protection in patients undergoing CAB, particularly when LV function is severely compromised.

Adult↗
PubMed1994

Effect of halothane on sarcolemmal calcium channels during myocardial ischemia and reperfusion.

The present results provide indirect support for other studies which showed that halothane inhibited the Ca2+ accumulation associated with myocardial ischemia in isolated guinea pig hearts (6), demonstrating a potentially beneficial effect of the anesthetic on the ischemic heart. The role of halothane in preventing ischemia-induced dysrhythmias and attenuation of free radical generation on reperfusion offers a new potential use during open heart surgery. The method of continuous perfusion of oxygenated blood cardioplegia, retrogradely, through the coronary sinus, enables a concomitant administration of the VA before and during the ischemic period of the cardiopulmonary bypass. Further studies may promote the use of the volatile anesthetic when myocardial ischemia and reperfusion are present during open heart surgery.

Animals↗
PubMed1994

Halothane modifies ischemia-associated injury to the voltage-sensitive calcium channels in canine heart sarcolemma.

BACKGROUND: Recent experimental data suggest that functional and metabolic changes in the myocardium caused during ischemia and subsequent reperfusion may be attenuated by the volatile anesthetics through the prevention of intracellular calcium accumulation. The main purpose of the current research is to identify a mechanism responsible for the alterations of ischemia-associated injury to the voltage-sensitive Ca2+ channels (VSCC) in the sarcolemma during halothane anesthesia. METHODS: The effect of 10 min myocardial ischemia in canine heart and 20 min reperfusion on the function of the VSCC in the sarcolemma was examined in the presence or absence of 1.6 vol% halothane administered in vivo. The membranes were isolated through differential centrifugation/filtration from the ischemic (left anterior descending territory) and normally perfused myocardium. Comparison of binding characteristics in the ischemic and nonischemic zones was made using equilibrium-binding studies of a dihydropyridine calcium channel blocker, [3H]isradipine (0.05-1.0 nM), to the VSCC in the sarcolemma. Control studies were performed on membranes prepared from the same perfusion zones, but from hearts who were not exposed to ischemia. RESULTS: The control studies (n = 5) showed no difference in binding kinetics between the different zones in the heart. After 10 min of ischemia, a 50 to 95% increase in specific [3H]isradipine binding to the sarcolemmal membranes was observed as compared to control membranes (P < 0.001). The maximal binding capacity (Bmax) increased by 85%, whereas the dissociation constant (Kd) remained unchanged. In the reperfusion experiments, a moderately increased binding (of 32%) was observed with a 40% increase in Bmax (P = NS). In the presence of 1.6% inhaled halothane, the effect of ischemia was attenuated. A decrease of 32.1% to 41.8% in equilibrium binding was observed (31% decrease in Bmax; P < 0.03 and 0.02, respectively). CONCLUSIONS: Even a brief period of myocardial ischemia produces a marked increase in the available high-affinity binding sites in the VSCC, a finding that is well correlated with previous experimental observation of increased calcium ion influx to the myocardial cell. On reperfusion, some recovery of the ischemic changes in the VSCC was evident. The binding kinetics which characterize this early phase of cell injury were reversed by halothane anesthesia, indicating a possible reduction in calcium entry, which may represent one of the beneficial effects of the anesthetic in the ischemic heart.

Animals↗
PubMed1994

Sciatic nerve palsy as a complication after acoustic neurinoma resection in the sitting position.

We present a case of sciatic neuropathy after operation in the sitting position. Sciatic nerve palsy as a complication of the sitting position appears to be extremely rare. The patient we describe was a short, plump woman. To attain optimal surgical exposure, a greater flexion of the hips than usual was utilized. That may explain the possible stretch injury of the sciatic nerve.

Adolescent↗
PubMed1994

Bupivacaine wound infiltration in thyroid surgery reduces postoperative pain and opioid demand.

Control of postoperative pain is an important element in preventing the modification of the excitability of the dorsal horn neurons. We studied the efficacy of bupivacaine 0.5% wound infiltration for postoperative pain management following thyroid surgery. Forty consecutive ASA I-II patients, scheduled for thyroidectomy, were assigned randomly to two groups. Group I (n = 20) consisted of patients receiving bupivacaine 0.5% (10 ml) wound infiltration at the end of surgery and group II (n = 20 included patients without infiltration. The patients did not know whether the wound had been anaesthetized or not. All patients received balanced inhalational anaesthesia, including fentanyl (a total dose of up to 4 micrograms.kg-1). Postoperative pain medication included morphine IV or IM, as needed. Twenty-four hours after surgery the worst pain was recorded using a visual analogue scoring system, from 0 to 10. Twenty-four hour postoperative morphine requirement was recorded. Groups did not differ in demographic data. Pain scores significantly different in the two groups. In group I, the mean pain score was 3.7 +/- 1.6 compared with 6.9 +/- 1.7 in group II (P < 0.05). Only six patients (30%) in group I received opioids and only one of these (5%) had a pain score above 5. In comparison, 18 patients (90%) in group II received morphine during the first postoperative day. The local injection of bupivacaine corresponds to a block of the superficial branches of the cervical plexus. This study demonstrated a simple, efficient and safe way to reduce pain perception following a thyroidectomy.

Adolescent↗