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Biomedical subjects

R Krivosic-Horber

Publications and source records attributed to R Krivosic-Horber.

At least 19 recordsLinked to original sources
PubMed1992

[Accidental spinal anesthesia in obstetrics. Limits of epidural test-dose].

Two cases of accidental spinal anaesthesia occurring in obstetrical patients are reported and discussed. Epidural anaesthesia had been asked for by the women, both being free from any significant medical history. A Tuohy needle was inserted in the midline between L3 and L4 with the patient sitting. The extradural space was identified by the loss of resistance using saline. The test-dose (2 ml and 4 ml of 1% lignocaine respectively) was administered five minutes before changing the patient to the supine position. In the first case, after a test-dose had remained without any effect, 8 ml of 0.25% bupivacaine were injected, about one hour later. The patient rapidly complained of paralysis of her legs and difficulties in breathing. Her blood pressure decreased from 120/80 mmHg to 90/60 mmHg. The upper level of analgesia reached T4. She improved after infusion of 1.51 of lactated Ringer's solution. Endotracheal intubation was not required. Delivery was assisted with a vacuum extractor. In the other patient, when the extradural space had been located, there was a small reflux of clear fluid which did not contain any glucose. As the test-dose did not result in any effect. 2 ml of 2% lignocaine with adrenaline were injected. This was followed by an immediate sensory loss in the legs, extending up to T10. Caesarean section was decided on, without any further injections (foetal macrosomia, breech presentation). Both patients totally recovered without any sequela. Both children had an Apgar score of 10 at 1 and 5 minutes. The type of test-dose is discussed. Smaller volumes of more concentrated solutions are recommended.

Adult↗
PubMed1992

[Cerebral aneurysms and pregnancy: 4 cases].

Haemorrhagic cerebral accidents are the commonest neurosurgical diagnoses made in pregnancy. The state of pregnancy makes it more likely that an arterial or an arteriovenous aneurysm will rupture and this is the principal cause of most haemorrhages. They occur more often in primiparae in the third trimester of pregnancy. The clinical picture is classical. The conformation of the diagnosis is made by scanning and angiography. The main differential diagnosis is eclampsia. Neurosurgical treatment should be carried out immediately whenever possible in order to avoid the two great risks that follow, namely recurrence of haemorrhage and secondly ischaemia. As far as the obstetric side is concerned, Caesarean section would only be indicated if: the clinical state of the mother is severe with coma and brain stem damage when the child is viable, if there is symptomatic vascular malformation diagnosed at term, if there is haemorrhagic arteriovenous malformation which is highly liable to occur and cannot be operated on without risks for the child if viable, if, finally, the interval between the surgical treatment of the condition and labour is less than 8 days. In all other cases a vaginal delivery is preferable under epidural anaesthetic which should be given if medical induction is carried out, and where instrumental delivery is being carried out systematically, unless radical treatment is being performed. The prognosis which is, in spite of all steps that may be taken, poor, depends on the initial neurosurgical stage and the nature of the causes of lesion and the possibilities of treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

[Obstetrical anesthesia of patients with disseminated lupus erythematosus].

The anaesthetic management of pregnant women who suffered from systemic lupus erythematosus (SLE) was reviewed retrospectively. During the ten-year period studied, there were nineteen pregnancies in eighteen women (mean age 27 years) who had either SLE or an isolated lupus type anticoagulant (LAF). Four pregnancies were stopped before the third trimester, two spontaneously, and the other two because of the mother's condition. Of the fifteen remaining pregnancies, eight children were born with a weight less than 2,500 g. One child, birth weight 750 g, died after three days. None of the fourteen living children had neonatal lupus. Six epidural and twelve general anaesthetics were carried out for four abortions, nine Caesarian sections, and five deliveries. Epidural anaesthesia was often contraindicated by neurological and haemostatic complications of the SLE: recent meningitis, thrombocytopaenia, prolonged bleeding, anticoagulant therapy. In fact, management of SLE patients required extensive preanaesthetic clinical and paraclinical assessment, as all the systems may be involved in this condition; moreover, it may worsen during pregnancy (seven times in this series). The most frequent complications were cardiovascular, renal, and haematological. Possible intubation difficulties must also be looked for. A LAF was associated with a great number of venous thromboses. An isolated LAF does not contraindicate epidural anaesthesia, as long as there is no associated haemostatic defect, such as a thrombocytopaenia. Furthermore, the patient should not have had prolonged episodes of unexplained bleeding, or require anticoagulants. In the present series, epidural anaesthesia was contraindicated in three of the four patients with LAF. Finally, prevention of thromboembolism, postoperative infection and adrenal failure (in those patients with long-term steroid therapy) must be carried out.

Adult↗
PubMed1990

[Anesthetic technics for the difficult intubation].

Numerous anaesthetic techniques exist for a patient who presents with a difficult endotracheal intubation. They all require an anaesthetic protocol which cannot be improvised. When intubation is expected to be difficult at the pre-anaesthetic examination, the use of a fiberoptic bronchoscope is the technique of choice for intubating adults under local anaesthesia, and children under general anaesthesia. When a fiberoptic bronchoscope is not available, several alternatives can be suggested: local anaesthesia of the glottis, retro-molar and retrograde intubation, or the use of a guide threaded over a lighted stylet; these techniques can be used in an anaesthetized patient breathing spontaneously. In the paralyzed patient impossible to intubate, various trans-laryngeal techniques of ventilation can be used in emergency: jet ventilation via the trans-crico-thyroid route, the use of a cricotomy cannula, or a minitracheotomy set.

Anesthesia↗
PubMed1990

[Intravascular volume expansion and intravenous nimodipine in the treatment of cerebral vasospasm after surgical treatment of intracranial aneurysm].

The advantage of calcium antagonist on cerebral arterial spasm during the peri-operative period has been recently demonstrated. However, the role of volemia and cardiac output in the pathogenesis of arterial spasm seems predominant. The basal hemodynamic profile of 17 patients operated for an intracranial aneurysm was investigated. The hemodynamic and neurological modifications induced by treatment with nimodipine, modification of blood volume and the use of inotropic drug was subsequently analysed. In 8 patients there was a clearcut hypovolemia with diminished cardiac index whereas in 9 other patients there were low filling pressures with an unmodified cardiac index. As early as the 48th hour of treatment, there was an improvement of Hunt and Hess score in 12 patients whereas in 5 others the score remained unchanged. Two death occurred due to the extension of secondary ischemic lesions. This study seems to confirm the aggravating role of hypovolemia in the occurrence of vasospasm and the neurological improvement due to the association of a calcium antagonist, restoration of blood volume with or without a vasoconstrictor.

Adult↗
PubMed1989

[Central core disease associated with malignant hyperthermia sensitivity].

The authors report the case of a 57-year old woman who was susceptible to malignant hyperthermia (MH) and also had central core disease (CCD) of muscle. The latter was asymptomatic and was discovered when muscle biopsy was performed for in vitro tests of susceptibility to malignant hyperthermia. This case was compared with the 117 cases of CCD and 33 cases of CCD associated with MH published in the literature. Anaesthesia-induced MH is lethal in 80 per cent of the cases without treatment and in 20 per cent with treatment. CCD and MH are both transmitted as autosomal dominant traits. Susceptibility to MH is a functional abnormality of unknown mechanism. CCD is a disease of muscle fibre structure. One may hope that molecular studies and genetic probes will show whether or not these two diseases are transmitted by genes that are similar but distinct and independent.

Adolescent↗
PubMed1989

[Screening tests for malignant hyperthermia susceptibility].

The ideal screening test for malignant hyperthermia susceptibility (MHS) has yet to be discovered. It should be simple noninvasive, yet totally specific and sensitive. Until such an ideal test becomes available, allowing simple routine preoperative screening, tests should only be used in certain specific situations. These include: patients in whom a clinical crisis was suspected; the members of the family of a subject labeled MHS because of a fatal, or otherwise, crisis, or in whom tests were positive; patients with other pathological conditions which could be linked to malignant hyperthermia (MH) (some myopathies, effort or stress MH, neuroleptic malignant syndrome). The various tests proposed in the literature aim at revealing MHN subjects, using or not a triggering agent, halothane most often. However, detecting these abnormalities sometimes gives greater insight into the physiopathology of MH than in the detection of an individual patient's susceptibility. The tests have been classified as in vivo, electrophysiological, blood, and in vitro muscle biochemical, morphological, and pharmacological tests. The discovery of new tests gives renewed hope: CPK levels, platelet tests, calcium sarcoplasmic reticular reuptake, lymphocyte Quin 2 test, nuclear magnetic resonance spectroscopy. However, experts worldwide agree that the only reference test to this day remains the in vitro halothane caffeine contracture tests. These tests have shown their reliability; they must be performed on muscle strips obtained from surgically removed muscle biopsies, by laboratories used to this technique and who have at their disposal a sufficiently large group of MHS subjects with a clear-cut clinical crisis, as well as controls. The patients must therefore travel to these laboratories. The design of common protocols for European laboratories on one hand, and the North American laboratories on the other, is a good guarantee of the reliability of these tests.

Animals↗
PubMed1989

Effect of propofol on the malignant hyperthermia susceptible pig model.

Anaesthetic techniques for malignant hyperthermia susceptible (MHS) patients should include drugs which do not trigger MH and provide stress free conditions. Thus all new drugs should be screened for their susceptibility to trigger MH. We have screened propofol, using the MHS pig model. In none of the animals exposed to propofol, were there signs of MH, even after challenge with suxamethonium. However, the same animals developed MH when exposed to halothane alone or with suxamethonium. Despite the problems of extrapolating from this study to man, it is unlikely that propofol may trigger an episode of MH.

Anesthetics↗
PubMed1989

[Interaction of nimodipine and isoflurane in surgery of intracranial aneurysm].

A moderate controlled hypotension has been performed with isoflurane in the presence of nimodipine (4 mg.h-1) on ten patients anesthetized for cerebral aneurysm clipping. The administration of both drugs induced a dose-dependent hypotension secondary to the reduction of the systemic vascular resistance without impairment of cardiac index. Nimodipine did not modify the cardiovascular effects of isoflurane. It is concluded that intravenous administration of nimodipine should be continued during the operative period.

Drug Interactions↗
PubMed1988

[Calcium inhibitors and anesthesia].

Calcium blockers (CB) are routinely used. This could lead to possible interference with anaesthetic drugs. CB prevent calcium from entering the cell by inhibiting the slow voltage-dependent calcium channels. They act mostly on heart and smooth muscle. Of all the possible indications, the three that are confirmed are coronary heart disease, arterial hypertension and supraventricular rhythm disturbances. Most of the work published and the cases reported concerns interactions between CB and halogenated anaesthetic agents; the latter's actions on the heart depend on cellular calcium exchange. Also, the cardiovascular effects of these anaesthetics are similar to that of CB. Experimentally, halothane and enflurane have direct cardiac inhibitory effects similar to verapamil and diltiazem, whereas isoflurane's properties seem closer to the dihydropyridines (nifedipine and nicardipine). Giving verapamil or diltiazem increases the number of sino-atrial and atrio-ventricular blocks when using a halogenated agent. Clinically, interpreting the effects of CB during anaesthetic induction is difficult because of the pathology (coronary heart disease, cardiac failure), the other drugs (beta-blockers and nitrates) and the type of anaesthesia (emergency or elective). Interactions can give rise to anything from a severe cardiovascular collapse, requiring catecholamines, to a mild fall in blood pressure which responds well to plasma expansion, or even no effect on blood pressure. Rebound is seen on stopping CB in patients with coronary heart disease or arterial hypertension; stopping them before surgery does not therefore seem justified. However, extreme care must be taken when using halogenated agents for patients under treatment with CB and/or beta-blockers. A wary anaesthetist will be able to adapt the technique to the patient. It has been suggested that CB could be used to treat preoperatively myocardial ischaemia (diltiazem), hypertensive crises (nifedipine, nicardipine) and ventricular rhythm disturbances (verapamil); this must be done with caution, the patient being closely monitored (haemodynamic and electrocardiographic monitoring). Postoperatively, intranasal nifedipine, continuous intravenous nicardipine or diltiazem have been used to treat increases in arterial blood pressure during recovery and to adapt the cardiovascular system to the increased metabolic needs. Here again, close patient monitoring is essential. In any case, treatment with CB which has been stopped should be started up again as soon as possible.

Analgesics↗