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Biomedical subjects

F Pluskwa

Publications and source records attributed to F Pluskwa.

13 recordsLinked to original sources
PubMed1991

Effects of clonidine on variation of arterial blood pressure and heart rate during carotid artery surgery.

The effect of oral premedication with 300 micrograms of clonidine on systemic arterial pressure, heart rate, and plasma norepinephrine levels was assessed in a double-blinded, placebo-controlled study conducted in 29 patients subjected to carotid artery surgery (CAS). Anesthesia was induced with thiopental, 6 mg/kg, and alfentanil, 0.05 mg/kg, and maintained with alfentanil and 0.6% isoflurane in 50% N20/O2. The study was divided into five periods as follows: (1) anesthesia to start of surgery; (2) surgery to carotid artery clamping; (3) carotid artery clamping to unclamping; (4) carotid artery unclamping to the end of surgery; and (5) the first 4 postoperative hours in the recovery room. In the clonidine group (n = 14), plasma norepinephrine concentrations were significantly lower before induction of anesthesia and during the operative period. Heart rate and systemic arterial pressure were lower (P less than 0.01) in the clonidine group at 3 different time intervals (control, carotid clamping, carotid unclamping). However, during each of the previously defined periods, the variability of heart rate and systemic arterial pressure, assessed by the coefficient of variation, was not different between the two groups. The lability of these hemodynamic parameters, expressed as the percentage of values, which increased or decreased more than 20% of control values during the corresponding period, was also comparable between the two groups. The number of patients who experienced at least one episode of hypertension (systolic arterial pressure greater than 180 mm Hg), hypotension (systolic arterial pressure less than 100 mm Hg), or bradycardia less than 45 beats/min was not different between the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1991

Effect of epidural clonidine on analgesia and pharmacokinetics of epidural fentanyl in postoperative patients.

Epidural clonidine produces postoperative analgesia in patients and potentiates opioid analgesia in animals. The aim of the current study was to assess the effect of epidural clonidine on the plasma concentrations and analgesic effect of fentanyl after epidural administration. Twenty ASA physical status 2 or 3 patients recovering from abdominal surgery were allocated randomly to receive either epidural fentanyl (100 micrograms in 10 ml isotonic saline; EF group) or epidural fentanyl (same dose) plus epidural clonidine (150 micrograms; EF + C group) in isotonic saline solution. Analgesia was assessed over a period of 12 h after epidural injection. Venous samples were obtained until 360 min after epidural injection for radioimmunoassay determination of plasma fentanyl concentration. Onset of analgesia was similar in the two groups of patients (13 +/- 6 and 13 +/- 3 min, respectively, after injection), but duration was more than doubled in the patients receiving clonidine (543 +/- 183 vs. 250 +/- 64 min). Peak plasma fentanyl concentrations (Fmax) and the time to reach Cmax (Tmax) were comparable in the two groups (0.29 +/- 0.15 ng.ml-1 at 16.2 +/- 14.8 min in the EF group and 0.27 +/- 0.11 ng.ml-1 at 8.3 +/- 5.5 min in the EF + C group), as were plasma concentrations at each definite time of measurement. Drowsiness and hypotension were noticed in the EF + C group. Thus, epidural clonidine appears to prolong epidural fentanyl analgesia without affecting its plasma concentration.

Aged↗
PubMed1990

Cervical epidural anaesthesia for carotid artery surgery.

A series of 394 patients (251 men, 143 women; mean age 70.0 +/- 8.4 yr) selected for carotid artery surgery (CAS) performed under cervical epidural anaesthesia (CEA) was analysed retrospectively. Carotid endarterectomy was performed in 326 patients and saphenous vein bypass in 68. The cervical epidural administration of 15 ml 0.5 per cent bupivacaine or 0.37-0.40 per cent bupivacaine plus fentanyl (50-100 micrograms) resulted in an effective sensory blockade from C2 to T4-T8. Patients were maintained awake during the surgical procedure in comfortable condition. Serious complications included dural puncture in two patients, epidural venipuncture in six patients and respiratory muscle paralysis in three patients. Hypotension (10.9 per cent) and bradycardia (2.8 per cent) were the most frequent side-effects of CEA. Transient neurological events were noticed in 84 patients during the surgical procedure. A definite neurological deficit occurred postoperatively in 12 patients. Three patients suffered postoperative myocardial infarction. The mortality rate was 2.3 per cent (nine patients). Carotid artery surgery may be performed under CEA but haemodynamic variables should be monitored closely and managed closely during the procedure.

Aged↗
PubMed1989

[Cervical epidural anesthesia in carotid artery surgery].

A series of 394 patients who underwent surgery of the carotid artery under cervical extradural anaesthesia is presented. With this technique the patient remains conscious throughout the operation, which facilitates neurological monitoring. Due to failure or complication, extradural anaesthesia was abandoned and replaced by general anaesthesia in 1.5 per cent of the cases. The mortality rate in this series was 2.3 per cent; in 2 out of 3 cases death was of neurological origin; 21 per cent of the patients had peroperative neurological accidents which, in 9 out of 10 cases, were due to a low cerebral blood flow rate during clamping. Thirty-five intra-arterial shunts (8.9 per cent) were installed, and none of these accidents was permanent. Twenty-five patients (6.3 per cent) had postoperative deficit which did not regress in 12 cases (3 per cent). The risk of peroperative neurological accident was significantly increased in patients with bilateral lesions of the vertebral arteries (x 3.5) or with occlusion of the contralateral carotid artery (x 4.5). Surgery of the carotid artery in conscious patients reveals a high incidence of ischaemic neurological events the reversibility of which is ensured by appropriate therapeutic procedures (arterial shunt, increase of brain perfusion pressure). Patients at risk of neurological accidents may benefit from cervical extradural anaesthesia.

Aged↗
PubMed1989

[Comparison of blood pressure profiles with flunitrazepam/fentanyl/nitrous oxide vs cervical epidural anesthesia in surgery of the carotid artery].

A study was carried out to compare the evolution of arterial blood pressure during carotid endarterectomy performed under either general anaesthesia (GA) or cervical epidural anaesthesia (CEA). 20 patients were randomly assigned to two equal groups. In the CEA group, 15 ml of 0.375% bupivacaine and 150 micrograms fentanyl were injected into the epidural space at C7-D1 level. In the GA group, patients were anaesthetized with 0.2 mg.kg-1 flunitrazepam and 5 micrograms.kg-1 fentanyl; intubation was carried out using 0.08 mg.kg-1 vecuronium, and the patients were ventilated with a mixture of nitrous oxide and oxygen (50% of each). Further injections, every 30 min, of 2 micrograms.kg-1 fentanyl were given to the patients in group GA. Blood pressure was monitored continuously, up to 4 h postoperatively, with a radial arterial catheter. Per- or postoperative hypertension was defined as a rise in systolic arterial blood pressure (Pasys) over 180 mmHg for greater than 3 min; this was treated with 20 mg nifedipine intranasally (group CEA) or 100 micrograms fentanyl with 0.5 mg flunitrazepam with or without nifedipine (group GA). Per- or postoperative hypotension was defined as a fall in Pasys below 100 mmHg and or a 30% fall in mean arterial blood pressure for greater than 3 min; this was treated, in both groups, with an intravenous bolus of 3 mg ephedrine. Patients in group CEA experienced more frequent episodes of peroperative hypertension (8/2; p less than 0.02) and postoperative hypotension (5/1) than group GA.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1988

[Carotid endarterectomy under cervical epidural anesthesia. Analysis of neurologic manifestations].

Carotid endarterectomy can be complicated by neurological events due to different mechanisms. Monitoring cerebral function is difficult under general anaesthesia. By contrast, the monitoring of awareness and neurological deficit is very easy under regional anaesthesia. The aim of this study was to assess the requirement for arterial shunting during endarterectomy performed under cervical epidural anaesthesia, to analyse the neurological events and to compare the value of clinical and electroencephalographic monitoring. Sixty-four patients were included in this study. Cervical epidural anesthesia was performed with 0.375% bupivacaine and 100-150 micrograms fentanyl. In 19 high risk patients, a one-channel electroencephalographic filter processor (Cerebral function monitor, Critikon) was placed over the affected hemisphere. Before surgery, it was estimated, on angiographic and Doppler data, that 18 patients needed an arterial shunt for carotid clamping. An arterial shunt was in fact inserted during surgery in only four patients, because of cerebral ischaemia after carotid clamping. Transient obnubilation was observed during carotid clamping in three other patients; it disappeared on unclamping in two, and on increasing blood pressure in the third. An additional patient suffered from a very short loss of awareness after declamping, due to cerebral embolism. The cerebral function monitor never documented false positive results, but failed to detect one out of every five neurological events. Controlateral carotid occlusion and preoperative stroke were documented to correlate with peroperative neurological events. Cervical epidural anaesthesia, which maintains consciousness during surgery, reduced in high-risk patients the need for arterial shunting as well as that for the analysis of neurological events.

Aged↗
PubMed1987

Improved efficacy of spontaneous breathing with inspiratory pressure support.

During inspiratory pressure support (IPS) ventilation, first a negative airway pressure is produced by the patient to open a demand valve and then a constant positive airway pressure is maintained at a present level while the patient inhales. The aim of this study was to assess the ability of 10 cm H2O IPS to improve the efficacy of spontaneous ventilation. We studied 8 intubated patients recovering from acute respiratory failure, all were breathing spontaneously via 3 different systems: a Servo 900 C ventilator (SCV) without IPS, a Servo 900 C ventilator with 10 cm H2O IPS, and a continuous flow system (CFS). Compared with the CFS, breathing with the SVC without IPS resulted in an increased respiratory rate (RR), increased tidal Volume (VT), increased transdiaphragmatic pressure (Pdi), and no significant change in PaO2 or PaCO2. Ventilation with IPS resulted in significant improvements in VT, PaO2, and PaCO2 with a decreased RR and Pdi when compared with both the other modes of spontaneous ventilation. A significant decrease in the pressure-time index of the diaphragm (i.e., the product of the mean transdiaphragmatic pressure and the inspiratory duty cycle) occurred during IPS. In 2 patients, we recorded diaphragmatic electromyographic activity during both SVC and IPS. In both patients during IPS, an increased VT and a decreased Pdi coincided with a major reduction of electromyographic activity. We conclude that IPS at a level of 10 cm H2O markedly increases the efficacy of spontaneous breathing while reducing the activity of the inspiratory muscles.

Blood Gas Analysis↗
PubMed1986

Changes in intrathoracic pressures induced by positive end-expiratory pressure ventilation after cardiac surgical procedures.

The consequences of controlled ventilation with positive end-expiratory pressure (PEEP) were studied, after cardiac surgical procedures, in two groups of patients supposed to have different lung and chest wall mechanical properties. The first group included 6 patients who had undergone coronary artery graft surgical procedures (CGS). The second group included 5 patients who had undergone a mitral valve replacement (MVR). Postoperatively, static lung and chest wall compliance was measured by stepwise inflation and deflation of the thorax. Esophageal, pericardial, and pleural pressures were then measured, and cardiac output was determined while PEEP was increased from 0 to 20 cm H2O. Lung and chest wall compliance values sharply decreased in MVR patients. This accounts for the lower values for pleural and pericardial pressures in this group than in the CGS patient group, but the transmission of airway pressure was identical in the two groups when PEEP was increased. The decrease in cardiac output induced by PEEP was similar in the two groups. The results suggest that the opposing influences of lung and chest wall compliance on airway pressure transmission could at least partly explain the hemodynamic effects of PEEP in patients in whom the mechanical properties of the lung and thorax are impaired. PEEP ventilation should be used cautiously in patients suspected of having thoracic rigidity.

Cardiac Output↗
PubMedDate not supplied

Carotid surgery. Is regional anesthesia always appropriate?

We retrospectively studied a series of 385 carotid endarterectomies performed either under general anesthesia (242) or under local anesthesia (145) to compare the peri-operative mortality and morbidity rate and to identify factors which may influence the choice of anesthesia. The rate of transient ischaemic attacks (TIA), stroke, death, combined mortality, severe neurological and cardiac morbidity were not statistically different. Under general anesthesia, more shunts were inserted (17% versus 7%, p less than 0.05) and more myocardial infarctions occurred (5% versus 0%, p less than 0.05). However, more strokes due to technical imperfection were seen under regional anesthesia. We concluded that regional anesthesia is more appropriate in patients with coronary artery disease and in patients at risk of intolerance to cross clamping. General anesthesia is more appropriate in poorly cooperative patients or in those with unfavorable operative conditions.

Anesthesia, Conduction↗