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Biomedical subjects

P Feiss

Publications and source records attributed to P Feiss.

At least 73 records · Page 4Linked to original sources

[Role of vitamin C on adrenocortical effects of etomidate].

This study was carried out to assess whether the adrenal inhibition induced by etomidate could be prevented by associating ascorbic acid with etomidate, as a protective effect of ascorbic acid administered three hours after etomidate has been described. Sixteen ASA 1 or 2 patients, less than 65 years old, free of endocrine disease, were included. At induction of anaesthesia, eight of them (group B) were given an infusion of ascorbic acid 1 g, in 500 ml of 5% glucose. Group A patients (n = 8) were given 500 ml of 5% glucose. Anaesthesia was induced with etomidate 0.3 mg.kg-1, fentanyl 0.005 mg.kg-1 and vecuronium 0.1 mg.kg-1. Maintenance was carried out using a continuous infusion of etomidate (0.1 mg.kg-1.h-1 for 10 min, followed by 0.01 to 0.02 mg.kg-1.h-1). Additional boluses of fentanyl or diazepam (10 mg) were administered when arterial blood pressure or heart rate were 20% greater than preanaesthetic values. The number of injections required was the same in both groups. Plasma cortisol concentrations were measured by radioimmunoassay (RIA) before anaesthesia (T0), 4 h (T4) and 24 h (T24) after the end of surgery. Blood ACTH levels were also assessed by RIA at T0 and T4. The adrenal insufficiency at T4 had completely ended at T24. In fact, the relative decrease in cortisol levels was greater in patients treated with ascorbic acid (T4/T0: 47.6 +/- 9% in group A vs 76.5 +/- 33% in group B, p less than 0.05); this was suggestive of a higher degree of adrenal inhibition in patients receiving ascorbic acid.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Cortex↗

[Closed-circuit anesthesia].

Closed circuit anesthesia answers the objections to open and semi-closed systems that are related to high delivery flow rates: pollution, cost, efficiency and the hydration of inhaled gases. But closed circuit anesthesia requires a good understanding of the amount of anesthetic agenda needed, and a convenient method of administering it. It is necessary use a reliable oxygen analyser, a carbon dioxide monitor and a circuit volatile agent analyzer.

Anesthesia, Closed-Circuit↗

[Techniques of autologous transfusion in hip surgery: a retrospective study].

A retrospective study was carried out on 99 patients undergoing hip surgery to evaluate the efficacy of three autotransfusion techniques on sparing of homologous blood. Preoperative normovolemic hemodilution (HDN), delayed autotransfusion (ATD) and recuperation of blood lost during surgery (RSPO) were studied. Patients were divided into 5 groups: group HDN, group ATD, group ATD + HDN, group RSPO, and the control group. The hematocrit was followed intra and postoperatively within these five groups, and mean values homologous blood transfusions calculated for each group. Comparison of mean values was performed using variance analysis (p less than 0.02). The association of delayed autotransfusion and preoperative hemodilution was most effective in sparing homologous blood (0.11 +/- 0.3 unit, p less than 0.02): however these results were obtained with a substantial drop in hematocrit which fell well below the 30% minimal accepted value at the end of the operation. There was no significant difference between delayed autotransfusion (0.35 +/- 0.8 unit) and preoperative hemodilution (0.7 +/- .01 unit) in sparing homologous blood. Hematocrit values with delayed autotransfusion were greater than these obtained with preoperative hemodilution. The difference was significant at the beginning of the operation (p less than 0.001), but not significant at the end. Recuperation of blood lost during surgery was least effective in sparing homologous blood (1 +/- 1.2 unit, p less than 0.02). Because of the moderate decrease in hematocrit, there are very few contraindications to delayed autotransfusion. Recuperation of blood lost during surgery should be associated with another autotransfusion technique.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

[Automated system for the inhalation administration of anesthetics in a closed circuit].

A rebreathing closed-circuit (Dräger) has been modified adjoining an automated device to inject volatile anaesthetics, thus replacing the usual vaporizer. The input of anaesthetic drug is separated from that of fresh gases: its rate of administration can thus be maintained precisely. This apparatus leads to obtain and maintain any desired concentration of the required anaesthetic. In our experiences, this device allows for a very satisfactory regulation of the alveolar concentration of the volatile anaesthetic. In addition, this apparatus is able to measure the injected volume of liquid anaesthetic and includes several devices aimed at increasing both safety and versatility.

Anesthesia, Inhalation↗

[Nimodipine and cerebrovascular circulation. Initial results apropos of 4 cases of subarachnoid hemorrhage].

Nimodipine was included in the treatment of four patients who had previously presented subarachnoid hemorrhage; cerebral circulation has been assayed by means of "Tomophygmographie cérébrale ultra-sonore". In all four patients, use of Nimodipine has led to an improvement of cerebral circulation and then of the neurological status. Nimodipine is characterized by its very low therapeutic inertion. Data obtained both at the initiation and on interruption of the administration of this drug points to its original properties regarding cerebral circulation: indeed, the present observations suggest that Nimodipine behaves as a true vasoregulator.

Cerebrovascular Circulation↗

[Use of isoflurane in a closed-circuit. Economic advantages].

The present study was designed to assess whether isoflurane requirement was significantly affected by fresh gas flow in a closed-circuit system. Sixty patients scheduled for orthopaedic procedures were randomly assigned into three groups. In group A (n = 20), anaesthesia was conducted with a fresh gas flow of 482.5 +/- 186.6 ml X min-1, corresponding to the patient's metabolic demand. In group B (n = 20), the fresh gas flow was 2000 ml X min-1. In group C (n = 20), it was adjusted to the ventilation minute, i.e. 7145 +/- 986 ml X min-1. Artificial ventilation was conducted using a tidal volume of 10 ml X kg-1 and a rate of 10 to 12 c X min-1. Anaesthesia was induced after 10 min denitrogenation with fentanyl (4 micrograms X kg-1), thiopentone (4 mg X kg-1) and vecuronium (0.1 mg X kg-1). FIO2 was then brought to 0.5 in nitrous oxide and was monitored continuously using a polarographic oxymeter. Liquid isoflurane was injected in the expiratory limb of the circuit using an electrical syringe driver. Alveolar concentration of isoflurane was set at 0.92 vol. % according to Lowe and Ernst. Statistical analysis was carried out using Student's test for means. Anaesthesia lasted 138 +/- 88.3 min in group A, 125.5 +/- 45.1 min in group B and 146.5 +/- 50 min in group C, no difference being significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

[Propofol in the surgery of the aortic bifurcation. Comparison with isoflurane].

Two groups of nine patients each, all undergoing surgery for aorto-bifemoral prosthesis, were studied. They were premedicated with 10 mg morphine and 1 mg flunitrazepam. A Swan-Ganz catheter was then inserted. Cardiac output was measured by thermodilution. Haemodynamic parameters were measured before induction (t0), 15 min after intubation (t1), 10 min after the start of the surgical procedure (t2), 5 min before clamping the aorta (t3), whilst the aorta was clamped (t4), and a few minutes after unclamping. Group A received 2 mg X kg-1 propofol at induction, anaesthesia being maintained with 100 micrograms X kg-1 X min-1 propofol. Group B received 4 mg X kg-1 thiopentone, followed by isoflurane at the dose of 0.9 vol. %. Both groups received 5 micrograms X kg-1 fentanyl and 0.1 mg X kg-1 vecuronium to ease intubation. Artificial respiration was carried out with a mixture of 40% oxygen and 60% nitrous oxide. The fall in blood pressure between t2 and t3 was significantly more important in the propofol group (-16%). In the same group, the systolic blood pressure and heart rate fell by 23 and 19% respectively after induction (p less than 0.05); the cardiac index fell by 20% and the systemic vascular resistances did not change. The fall in blood pressure, heart rate and cardiac index were not significant for group B. The haemodynamic changes due to clamping of the aorta were not significant between or within groups. In group A, one patient presented with bradycardia, hypotension and myocardial ischaemia, and another died of postoperative ventricular fibrillation.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

[The value of monitoring arterial oxygenation saturation by pulse oximetry in neuroleptanalgesia].

Anaesthesia can induce hypoxaemia. Pulse oximetry gives continuous non invasive monitoring of arterial oxygen saturation. No arterial puncture is needed. Ninety-four patients were monitored by pulse oximetry during neuroleptanalgesia for colonoscopy. Eighteen patients showed desaturation episodes of less than 90%, eight linked to opioid-induced respiratory depression. In all patients, pulse oximetry gave clinicians an immediate awareness of the incident. Treatment was facilitated. Pulse oximetry made anaesthesia safer.

Blood Gas Monitoring, Transcutaneous↗

[Pulse oximeter. Clinical assessment in the recovery room].

Fifty unselected recovery room patients were monitored using a Nellcor N101 pulse oximeter. Non invasive SaO2 values were compared with simultaneous spectrophotometric measurements made on arterial blood samples (Co-oximeter). Mean pulse oximeter SaO2 was 86.9 +/- 6.08%, with extreme values of 68 and 95.5%. Arterial blood SaO2 was 91.25 +/- 6.28%, with extreme values of 66 and 100%. Linear regression analysis showed a good correlation between the two sets of measures (r = 0.97; p less than 0.005). Twenty one patients had a SaO2 below 90% (mean: 84.83 +/- 5.93%); their measured arterial SaO2 was of 86.14 +/- 6.32%. The correlation between the two sets of low values was good (r = 0.96; p less than 0.05). Pulse oximetry was a non invasive reliable method, but there were some limits to its clinical use. Hypothermia or shock vasoconstriction precluded the measurement of SaO2. Restlessness or shivering were responsible of probe dysfunction and false alarms. False SaO2 readings may result from high levels of carboxyhaemoglobin or dye infusion. Also, each disposable finger probe was reused for a mean of five patients, its cost being relatively high (170 FF, i.e. 28.3 US dollars).

Adult↗

[Accidental deep hypothermia and circulatory arrest. Treatment with extracorporeal circulation].

A 27-year old female was discovered at 4 a.m. lying in a wet field, the ambient temperature being of 4 degrees C. Her rectal temperature had fallen to 19 degrees C. She was comatose and failed to respond to noxious stimuli. Her pupils were dilated and fixed. Her respiratory rate was reduced to three to four breaths per min. Her blood pressure was not measurable and neither femoral or carotid pulse could be detected. The heart was in sinus rhythm with a rate of 40 b X min-1. During her transfer to hospital, she was ventilated with oxygen, a tidal volume of 300 ml and a rate of 10 b X min-1. On arrival in the emergency room, a short period of ventricular fibrillation preceded cardiac arrest. Cardiac massage and sodium bicarbonate infusion were continued during the transfer of the patient to the operating theatre. A femoro-femoral cardiopulmonary bypass was started with a bloodless priming, 3 mg X kg-1 heparin and a flow of 3,000 to 3,500 ml X min-1. Mean arterial pressure was maintained between 65 and 85 mmHg; cardiac massage was discontinued during the bypass. Within 50 min, ventricular fibrillation appeared, rectal temperature had increased to 33 degrees C. Electrical defibrillation (300 J) was successful. Cardiopulmonary bypass was stopped after 63 min. The postoperative course was uneventful, apart from transient pulmonary oedema. At the time of discharge, a week later, no loss of intellect or change in behaviour could be perceived.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗