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Biomedical subjects

N Valentin

Publications and source records attributed to N Valentin.

At least 37 records · Page 2Linked to original sources
PubMed1991

[Ignition of the endotracheal tube during CO2 laser therapy of upper airway disorders].

The patient had papillomas in larynx, trachea and the main bronchi and was treated with CO2-laser evaporation under general anaesthesia. He was intubated with a red rubber tube wrapped with aluminum tape and outermost with muslin strips. The muslin was soaked in water before intubation. After using the CO2-laser with 15W for 3-5 s a continuous smoke generation was seen. The muslin strips had glowed away. The fire was immediately extinguished with water and no damage to the airway had occurred.

Bronchial Neoplasms↗
PubMed1991

Arterial desaturation in healthy children during and after minor surgery.

Pulse oximetry (PO) was applied to 79 otherwise healthy children during and after minor ENT surgery under general anaesthesia in private practice. The PO data were not available to the anaesthetist unless desaturation to less than or equal to 85% was present for greater than or equal to 30 s. This occurred in 12 and 9 cases during anaesthesia and recovery, respectively, only 8 and 5 cases, respectively, being diagnosed clinically. Desaturation during and after anaesthesia was more common in children undergoing adenoidectomy than during procedures for which endotracheal intubation was not performed. During recovery, desaturation was more likely to occur in the same patients again. Lower values of SaO2 were found in younger children and in children resisting or crying at induction. There was a (weak) negative correlation between SaO2 and HR. As clinically undiagnosed desaturation occurs even in healthy children undergoing minor surgical procedures, a more widespread use of PO during and after anaesthesia may be advisable.

Adenoidectomy↗
PubMed1991

Recovery after total intravenous anaesthesia using combined midazolam/alfentanil infusion and reversal with flumazenil.

One of the major problems with total intravenous anaesthesia (TIVA) is postoperative sedation, possibly with respiratory depression. The aim of the present study was to evaluate the recovery characteristics after TIVA using a continuous infusion of a mixture of midazolam and alfentanil with flumazenil reversal before extubation. This method was compared to balanced anaesthesia using midazolam, alfentanil and nitrous oxide without flumazenil reversal. The degree of sedation was measured by reaction time test, Glasgow Coma Scale, cipher copying test and subtraction test. We found significantly faster reaction times postoperatively in the TIVA group (n = 15) compared to the balanced group (n = 13), despite larger doses of both midazolam (median 21 mg versus 9 mg) and alfentanil (median 5.9 mg versus 4.5 mg). The other tests revealed no difference between the groups. One patient became resedated after flumazenil. We conclude that the TIVA technique described here resulted in slightly better recovery characteristics, offering a usable alternative to balanced anaesthesia.

Acoustic Stimulation↗
PubMed1990

HLA-DRw52a is involved in alloimmunization against PL-A1 antigen.

The alloimmunization against the platelet PL-A1 antigen is strongly associated with a HLA class II structure in mothers of thrombocytopenic neonates. Most of the immunized women have first been shown to possess the DR3 specificity and subsequently the DRw52 allele. The 18 immunized mothers studied here by restriction fragment length polymorphism analysis had the DRw52a specificity at the DRB3 locus whatever their HLA-DRB1 gene product. This finding strongly suggests that the DRB3 chain is directly involved in the presentation of the PL-A1 antigen to the specific T cell. In addition, the similarities between DR3 and DRw52 structures due to a hypothetical gene conversion event should be considered in order to understand the high frequency of DR3 among the DRw52a-responding women. Alternatively, the high frequency of DR3 among the DRw52-responding mothers might be due to the high responder status associated with the former specificity.

Antigens, Human Platelet↗
PubMed1990

[Total intravenous anesthesia using ketamine and midazolam. A simple technic].

Forty unpremedicated patients undergoing minor gynecological surgery were anesthetized with 1 mg ketamine and 0.1 mg midazolam per kg bodyweight, if necessary supplemented later with half the initial dose. All patients continued to breathe room air spontaneously with no ventilatory support. There were no incidents of airway obstruction and only 1 case of troublesome airway secretions. The arterial blood gas sample did not show any sign of respiratory depression, but in 11 cases paO2 was lower than normal, though acceptable. The median emergence time was 6 min. The side effects of ketamine were well controlled by midazolam, and patient acceptance of the technique was high. We consider that the technique may be suitable for short procedures under primitive conditions, for example after mass casualties, and that it can, if necessary, be applied by specially trained paramedics.

Adult↗
PubMed1989

The clinical effect of felodipine and nifedipine in Raynaud's phenomenon.

Sixteen patients participated in a double-blind cross-over trial comparing the effect of two dosages of the new calcium entry blocker, felodipine, with nifedipine in the treatment of Raynaud's phenomenon. The effect was evaluated using a symptom recording system. As no difference was found between the 3 treatments, the lower dose of felodipine (10 mg) may be preferable as only one dose per day is necessary.

Adolescent↗
PubMed1988

[Platelet phenotyping and study of alloantibodies using flow cytometry].

In this study, we describe a flow cytometric technic for the detection and characterization of platelet allo antibodies and for platelets grouping in the platelet group PLA. This new technique is a variant of the platelet suspension immuno fluorescence test. It is rapid, simple, sensitive and specific. So it is very useful in the cases of neonatal thrombocytopenia and posttransfusion purpura. Moreover, anti-HLA antibodies don't obstruct the detection of anti-PLA1 antibodies.

Antigens, Human Platelet↗
PubMed1986

Spinal or general anaesthesia for surgery of the fractured hip? A prospective study of mortality in 578 patients.

The mortality following surgical correction of upper femoral fractures was investigated in 578 patients, over the age of 50 yr, randomly allocated to receive spinal (bupivacaine) or general (enflurane or neurolept) anaesthesia. Thirty days after surgery the mortality was 6% after spinal and 8% after general anaesthesia (ns). Six months to 2 years after surgery the mortality was identical in the two groups. There were no differences with respect to ambulation and discharge. The estimated blood loss was smaller (P less than 0.05) in patients receiving spinal anaesthesia. Regardless of the anaesthetic technique, a high short-term mortality was related to age, male sex, and trochanteric fracture, whereas excess long-term mortality was related to male sex and high ASA scores.

Aged↗
PubMed1986

Glycopyrrolate during ketamine/diazepam anaesthesia. A double-blind comparison with atropine.

In a double-blind study, the effects of atropine and glycopyrrolate (dosage ratio 2:1) following i.m. and i.v. administration were compared with respect to salivation, heart rate, and blood pressure before, during and after i.v. infusion anaesthesia with ketamine and diazepam for alloplastic hip or knee surgery in 30 patients above the age of 50 years. Given with the premedicant, the two drugs were equally effective in reducing salivation. A slight increase in heart rate was seen after atropine only (P less than 0.005). Increases in heart rate and blood pressure during induction of anaesthesia were similar in the two groups. A second dose of the test drug was given with neostigmine for reversal of neuromuscular blockade. Again, there were no statistically significant differences with respect to salivation, blood pressure, heart rate, nausea and/or vomiting, unpleasant dreams and arousal time.

Aged↗
PubMed1985

Sister chromatid exchanges in cigarette smokers: effects of halothane, isoflurane or subarachnoid blockade.

In a previous study of the potential mutagenic action of isoflurane using the sister chromatid exchange (SCE) test in lymphocytes of surgical patients, it appeared that SCE increased in a group of 11 cigarette smokers, there being no effect in patients who were non-smokers. In the present study, 63 cigarette smokers were examined by the SCE test before and after minor orthopaedic operations undertaken under halothane or isoflurane anaesthesia, or subarachnoid analgesia. No significant changes of SCE were observed, and the risk of having missed a "true" increase of more than 0.6 SCE per cell was less than 1%. It was concluded that, in cigarette smokers, SCE in lymphocytes were unchanged after both general anaesthesia and subarachnoid analgesia, and that there was no indication from the SCE test of a mutagenic action of halothane, or isofurane, in nitrous oxide.

Adolescent↗
PubMed1984

Sister chromatid exchanges in lymphocytes of humans anaesthetized with isoflurane.

The potential mutagenicity of isoflurane was investigated by the sister chromatid exchange (SCE) test using peripheral blood lymphocytes from patients before and after anaesthesia. Thirty patients, aged 18-59 yr (median 29.5 yr), were anaesthetized for minor orthopaedic operations with isoflurane and nitrous oxide in oxygen for 37-90 min (median 64 min). Venous blood samples were drawn before the induction of anaesthesia, immediately after completion of anaesthesia and on the following day. SCE was examined in 30 cells from each specimen. In the 30 patients, the SCE values observed immediately after completion of anaesthesia and the day after were not different statistically from the SCE values observed before the induction of anaesthesia. Separate statistical evaluation of SCE observed among the 19 non-smoking patients also revealed unchanged SCE values. In 11 cigarette-smoking patients (average 10 cigarettes per day), SCE was increased the day after operation when compared with SCE before the induction of anaesthesia (P less than 0.02). This might reflect differences in SCE formation attributable to the patients' smoking habits, but further studies of SCE in cigarette smokers are required to elucidate this. It was concluded that there was no indication, from the SCE test, of a mutagenic effect of short-term exposure to anaesthetic concentrations of isoflurane and nitrous oxide in oxygen.

Adolescent↗
PubMed1984

Effect of i.v. atropine on cardiac rhythm, heart rate, blood pressure and airway secretion during isoflurane anaesthesia.

Atropine, 0.01 mg kg-1, was given i.v. to 30 patients before mask anaesthesia with isoflurane. Controls (n = 28) received a placebo. ECG was recorded on tape throughout anaesthesia and analysed later. There were no ventricular arrhythmias, but six patients in the atropine group and two patients in the placebo group had supraventricular arrhythmias of very short duration. Most cases occurred shortly after atropine, i.e. before anaesthesia. Heart rate increased significantly in both groups, more so after atropine (up to 60%), and remained elevated. In both groups blood pressure fell after the induction of anaesthesia but was close to control during surgery. Suction of airway secretions was necessary in three placebo patients, but excessive secretions were not met. The frequency of airway reflexes was similar in the two groups. It is concluded that due to the pronounced tachycardia the routine use of i.v. atropine can hardly be recommended before mask anaesthesia with isoflurane.

Adolescent↗
PubMed1983

Immediate and long-term mental recovery from general versus epidural anesthesia in elderly patients.

The postoperative course of mental performance during the first week and at 3 months after operation was studied in 30 patients above the age of 60, undergoing total hip replacement arthroplasty. The patients were randomly allocated to receive either general anesthesia, epidural analgesia, or general anesthesia plus epidural analgesia. The surgically induced increase in plasma cortisol and glucose was inhibited in the two groups receiving epidural analgesia. Mental performance was studied with psychological methods. An equal degree of postoperative impairment of mental performance of 3-4 days' duration was found in all groups. Three months after surgery, mental function had improved slightly and to the same extent in all groups. We conclude that the after surgery, mental function had improved slightly and to the same extent in all groups. We conclude that the transient mental impairment occurring within the first postoperative week is caused by factors other than general anesthetic agents and the endocrine-metabolic response to surgery.

Aged↗
PubMed1983

Respiratory effect of THIP, a GABA-agonistic analgesic, during halothane anaesthesia.

THIP, 4, 5, 6, 7-tetrahydroisoxazolo (5,4-) pyridin-3-ol, is a GABA-agonistic drug with analgesic effect, but apparently without respiratory depressant properties in awake subjects. The effect of THIP on the CO2 ventilation response was tested before, during and at the end of halothane anaesthesia in six male patients and compared to a control group. As there was no indication of respiratory depression by THIP, the drug may have a future in the treatment of postoperative pain if an analgesic effect is confirmed under clinical conditions.

Adolescent↗