[General anesthesia for magnetic resonance. Experience on 100 cases]. / Anestesia generale per la risonanza magnetica. Esperienza su 100 casi.

The diffusion of magnetic resonance imaging as a powerful non-invasive diagnostic procedure has led to an increasing request for general anaesthesia in patients who cannot lie still and/or who cannot guarantee adequate spontaneous breathing during the procedure. We report our own experience in 100 patients of this kind, in whom the need for general anaesthesia was due to neurological problems and/or tender age. Anaesthesia and monitoring devices were either devoted of ferromagnetic properties (allowing their location near the patient; as the ARM-S88 portable ventilator, which we used for adult patients) or connected to the patient with long connectors (allowing their location outside the resonance magnetic field; as the Draeger-Babylog pressometric ventilator, which we used in pediatric patients). On these bases administration of intravenous (86 patients) and inhalation (14 patients) anaesthesia during magnetic resonance proved safe in our experience.

[Labetalol in the prophylaxis of postoperative arterial hypertension in surgery of the posterior cranial fossa]. / Il labetalolo come profilassi della ipertensione arteriosa post-operatoria nella chirurgia della fossa cranica posteriore.

Increased catecholamines are one of the factors responsible for post-operative arterial hypertension. In order to prevent this severe complication labetalol, an alpha and beta blocking drug, was infused following the closure of the dura mater in half of the patients studied. For two hours after surgery blood pressure values in treated patients were constantly lower than those recorded in the control group, thus confirming the efficacy of this drug in preventing the cardiocirculatory effects of increased adrenalin and noradrenalin.

Sensitivity to curare in patients with upper and lower motor neurone dysfunction.

Sensitivity to the action of nondepolarising relaxants was compared in muscles of upper and lower limbs in four syringomyelic patients undergoing elective neurosurgical procedures. It was observed that muscles with signs of lower motor neurone dysfunction are supersensitive to the action of nondepolarising relaxants. Terminal sprouting of motor axons and the occurrence of newly formed neuromuscular junctions may be responsible for a low synaptic efficacy and may explain the high sensitivity to factors that reduce the safety margin of neuromuscular transmission.

A short plasma exchange protocol is effective in severe myasthenia gravis.

Plasma exchange has been reported to be a successful therapeutic procedure for the treatment of severely compromised myasthenic patients, but the optimal regimen in terms of costs or clinical benefit has not so far been determined. We have investigated the efficacy of a short plasmapheresis protocol of two exchanges 1 day apart in a series of 70 patients with severe forms of myasthenia gravis. Patients were evaluated before and 7 days after the first exchange. A positive outcome was observed in 70% of the plasma exchange cycles performed. Disease severity did not seem to be a negative prognostic factor for the efficacy of this short protocol, which was well tolerated by patients. In only 1 case were major side-effects observed. In spite of its short duration, the exchange treatment plus concomitant immunosuppressive drug therapy was not followed by early clinical deterioration.

[Pre- and postoperative evaluation of plasma creatine kinase in 142 children subjected to "uncomplicated" anesthesia in muscle biopsy]. / Valutazione pre e postoperatoria della creatinkinasi plasmatica in 142 bambini sottoposti "senza complicazioni" ad anestesia per biopsia muscolare.

Pre- and postoperative serum CK activity is evaluated in 142 children submitted, "uneventfully", to diagnostic muscle biopsy under halothane (77 patients), ketamine (50 patients) or "local" (15 patients) anaesthesia. The purpose was to ascertain whether or not anaesthesia-induced-rhabdomyolysis (AR) was an asymptomatic (and unrecognized) complication of "uneventful" anaesthesia. The majority of patients with low preoperative CK values showed a slight increase of serum CK activity on the first postoperative day. On the contrary, a postoperative decrease was observed in the majority of patients with high preoperative values (namely in almost all ketamine patients and in 2/3 of halothane-patients). In no case postoperative increase reached a value suggesting the occurrence of AR even though a postoperative value of 16480 U/I was observed in a patient with Duchenne muscular dystrophy after halothane anaesthesia. Sudden interruption of motor activity induced by general anaesthesia seems to be the most important factor in reducing the release of CK from muscle. When preoperative release is low, any further postoperative reduction is not sufficient to balance the moderate increase of CK produced by the surgical procedure; the opposite should happen in patients presenting with high preoperative release. So far as anaesthetics are concerned, our data seem to suggest that ketamine has a higher "protective" role compared to halothane.

Single donor plasma in therapeutic plasma exchange for myasthenia gravis.

Thirty-seven myasthenic patients were treated with therapeutic plasma exchange (TPE) on different performance schedules using either random or single donor plasma. The two schedules had the same effects in terms of efficacy but single donor replacement gave significantly less side effects in the short and long term. A two exchange procedure on alternate days associated with immunosuppression seems to be an optimal schedule for the treatment of myasthenic patients. A single donor two-exchange on alternate days procedure appears to be safe, useful and can be repeated in patients who need frequent TPE.