Biomedical subjects
A Levati
Publications and source records attributed to A Levati.
SIAARTI-SARNePI Guidelines for sedation in pediatric neuroradiology.
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[Anesthesia in early surgery and endovascular therapy for aneurysmic subarachnoid hemorrhage].
Early surgery after SAH is frequently performed. The most important problems for anesthesiologists are the risk of rebleeding, the alteration of autoregulation and CO2 responsiveness, cardiac, respiratory and electrolytic alterations. In this phase the brain may be ischemic-edematous or haemorrhagic-compressive and the choice of anesthetic agent is made on the basis of cerebral conditions. The main goal is to control ICP and maintain adequate CPP. The endovascular treatment with Guglielmi detachable coils is usually performed in patients with poor neurologic and/or medical conditions. General anaesthesia under aggressive monitoring is advisable to control systemic pressure and to avoid movements.
Prevention and treatment of vasospasm.
Cerebral vasospasm is a frequent and severe complication of SAH. Angiographic vasospasm may be seen in 70% of patients and delayed cerebral ischemic deficits are observed in 30% of patients. Since vasodilator drugs cannot reverse cerebral vasospasm, treatment is directed to prevent vasospasm and to prevent or reverse ischemic deficits. The mainstay of treatment of vasospasm is the hypertensive hypervolemia dilution (triple H therapy); the mainstay of prevention is the calcium channel blocker nimodipine. The efficacy of triple H therapy has not been demonstrated in randomized clinical trials, while several randomized trials have demonstrated that nimodipine reduces poor outcome due to vasospasm in all grades of patients. Some randomized, clinical trials are recently performed on the efficacy of rTPA (on the basis of the correlation between the amount of cisternal blood and the incidence and severity of vasospasm) and of tirilazed (on the basis of the role of lipidic peroxidation and free radical generation in the pathogenesis of spasm). Balloon angioplasty and/or super-selective intra-arterial infusion of papaverine can be considered when patient is refractory to medical and pharmacological treatment.
Contribution of the neuro-intensivist in the choice of treatment of patients with aneurysm.
During the last years embolization with Guglielmi detachable coils has provided a new alternative of treatment of intracranial aneurysms. Neuroanesthesiologists and neurointensivists have an important role in the selection of the patients to traditional surgical treatment or endovascular treatment. This selection must be a team decision on the basis of the patient's conditions. The main contribution of neuroanesthesiologists is to evaluate the patient's medical and neurologic conditions and to prospect the anesthesiological problems in each technique, especially when the patient is treated in acute phase after SAH.
Multidisciplinary (surgical and endovascular) approach to intracranial aneurysms.
In spite of the availability of the new endovascular technique (GDC) to manage cerebral aneurysms, to date, the crucial question "which is the proper treatment in a given patient?" still remains unsettled. In order to check whether an answer is possible, we retrospectively reviewed a personal series of 192 consecutive patients with cerebral aneurysms (1993-1995). We found 164 patients who had been considered eligible for active aneurysm treatment. Treatment modality has been chosen case by case on the basis of patient conditions, and aneurysm size and location. Four groups of patients were identified: Group 1: 104 patients (63.4%) with subarachnoid hemorrhage (SAH) in whom the treatment of choice was surgery; Group 2: 27 SAH patients (16.4%) in whom the first choice was GDC; Group 3: 7 SAH patients (4.2%) who died before the scheduled treatment; Group 4: 26 patients (15%) with not ruptured aneurysm who had either surgery or GDC. Based on the results of this series (improvement of the overall results through the multidisciplinary approach), we have developed the guidelines to prospectively manage future cases of cerebral aneurysms with the purpose to rationalize the management, thus further improving the overall results.
Peri-operative prophylaxis with phenytoin: dosage and therapeutic plasma levels.
Early postoperative epilepsy is a frequent complication of supratentorial intracranial surgery. The lack of consensus on prophylaxis of early postoperative seizures with phenytoin (PHT) may be due to the different dosages used in several studies, owing to inadequate therapeutic plasma level. The aim of this study was to evaluate which dosage of PHT can maintain the therapeutic range in the early postoperative period. Twenty patients operated on for supratentorial neoplasms were randomly allocated to receive, during the last hour of the surgical procedure, loading doses of either 10 mg/kg (group A, n = 10) or 15 mg/kg (group B, n = 10) of PHT. PHT infusion rate never exceeded 30 mg/min. Six hours after the loading dose, PHT maintenance treatment (250 mg, i.v., every 8 hours) was started in all patients. PHT plasma levels were evaluated from the end of the intra-operative loading infusion up to 24 h. During the first six hours after the loading dose, phenytoin plasma levels fell below the therapeutic range (10-20 mg/l) in 7 out of the 10 patients receiving 10 mg/kg, while in the patients treated with 15 mg/kg, PHT plasma levels were always in the therapeutic range (P < or = 0.0001). PHT maintenance dose was sufficient to keep plasma levels within the therapeutic range in 8 patients in group A, and in all the patients in group B. It is concluded that a loading dose of 15 mg/kg, followed by postoperative treatment, is necessary to guarantee therapeutic plasma levels of phenytoin in the immediate postoperative period, when seizure risk is very high.
Propofol anaesthesia in spontaneously breathing paediatric patients during magnetic resonance imaging.
BACKGROUND: The aim of this study was to evaluate the use of propofol to induce and maintain anaesthesia in spontaneously breathing paediatric patients (age 2 weeks-11 years) during Magnetic Resonance Imaging (MRI) of the CNS. METHODS: All patients were spontaneously breathing, without intubation, and received supplemental O2. Pulse rate, blood pressure (BP), electrocardiogram and EtCO2 were recorded in all patients, and in 38 subjects SpO2 was also monitored. Patients were divided in 2 groups according to their body weights: Group A (n = 34, bwt < or = 10 kg), and Group B (n = 48, bwt > 10 kg). RESULTS: Dosage of propofol during the time of induction (from insertion of the i.v. cannula to positioning on the MRI table) was significantly higher in smaller children (Group A; 5.4 +/- 2.2 (SD) mg/kg) as compared to children with bwt above 10 kg (Group B; 3.7 +/- 1.6 mg/kg). Propofol dosage for maintenance of anaesthesia was significantly higher in smaller children (Group A: 10.1 +/- 5.7 vs Group B: 7.1 +/- 3.0 mgkg-1 h-1, P = 0.003). During the time of induction, transient episodes of reduced BP (< or = 20%) occurred in 6 patients in Group A and 2 patients in Group B. During anaesthesia in Group B there was 1 episode of oxygen desaturation (95%), and 3 episodes of short and mild increases of EtCO2(< or = 52 mmHg). No other side effects occurred in any patient. MRI studies were successfully completed, only 3 sequences (Group A) had to be restarted. CONCLUSION: Propofol can be safely used for total intravenous anaesthesia in children undergoing MRI.
[Adequacy of admission in neurosurgical intensive care].
OBJECTIVE: The Intensive Care Units of Milano metropolitan area are characterized by difficulties of hospitalization for acutely injured patients due to the low bed availability. We evaluated the problem trying to find out possible solutions. DESIGN: On the day of achieved neurological and neurosurgical stability-defined as the day when the intracranial pressure and jugular venous oxygen saturation monitoring, hyperventilation, osmotic therapy were considered no longer needed--the monitoring procedures and instrumental and/or pharmacological treatments that the patients received were recorded and classified as follows: 1) intensive, 2) intermediate, 3) non-intensive. PATIENTS: All the acutely injured patients admitted at five Neurosurgical ICUs during June-July and October-November 1994 have been studied. Only one of these ICUs had a "sub-intensive unit". MEASUREMENTS AND MAIN RESULTS: 391 patients (29.9%) aneurysms and arteriovenous malformations, 25.1% tumours, 2.8% head injuries, 8.7% spontaneous intracranial haematomas, 13.5% various pathologies) were studied. Out of them 358 had an acute brain failure. 16.5% died during brain failure and 83.5% reached neurological stability within 3 days. When neurological stability was reached 32.1% of patients could be classified as "intensive", 63.6% as "intermediate" and 4.3% as "unintensive". In the four ICUs, without sub-intensive ward facilities, 361 patients were admitted with a total amount of 2292 days of hospitalization. Among them 61.9% were spent for a) patients with no brain injury (32 pts/113 days), b) postoperative patients (113 pts/167 days), c) patients in stable neurological conditions (159 pts/1139 days). Therefore, only 38% of the days recorded were given to patients that needed neurointensive care. CONCLUSION: Out data suggest that the receptivity for acute injured patients could be increased creating recovery room units and intermediate post-intensive units together with a better interchange between general and neurosurgical ICUs.
Total intravenous anesthesia with propofol in pediatric patients for MR examination.
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[Propofol anesthesia in spontaneous respiration in pediatric patients undergoing nuclear magnetic resonance].
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[Risk of postoperative epilepsy in acute surgery of cerebral aneurysms].
Forty-nine patients operated during an early clipping phase of cerebral aneurysm were reviewed; none had an associated ventricular flooding and/or intraparenchymal hematoma. Starting from the day of operation 37 patients were treated with anticonvulsant drugs using methods and dosages where were unlikely to guarantee efficacious cover. Forty-two patients made a satisfactory recovery, 5 patients died and 2 had severe neurological sequelae; 2 patients (4.4%) had early seizures during the first week after operation. In view of the inadequate cover of the anticonvulsant drugs and the homogeneous clinical characteristics of patients included in the study, the low number of attacks suggests an overall re-evaluation of anticonvulsant treatment and the need to select patients with a higher risk of an epileptic attack.
[Early epilepsy in surgery of extra-axial supratentorial neoplasms].
A retrospective study was performed to evaluate the incidence of seizure and anticonvulsant prophylaxis in 138 patients operated from september 1987 to august 1989 for extra-axial supratentorial tumors. 15 patients (10.9%) developed seizures in the early post-operative period. We have considered the importance of histological type and side of lesions, a previous history of epilepsy and the pre and intraoperative prophylaxis. We can say that there is a statistical significance between sellar and middle cranial fossa tumors and the frequency of post-operative epilepsy and that anticonvulsant prophylaxis can reduce post-operative seizure. There is no statistical significance between the previous history of epilepsy the type of anesthesia and post-operative seizure.
Continuous intraoperative electroencephalographic monitoring in carotid endarterectomy.
Continuous electroencephalographic (EEG) monitoring was done during 143 consecutive carotid endarterectomies in 130 patients to detect intolerance to cross-clamping. An intraluminal shunt was inserted when EEG changes appeared (in the first 100 procedures) or when EEG changes appeared and a long clamping time was supposed (in the last 43 cases). 121 patients had no EEG changes at clamping time and only 1 had a postoperative deficit due to embolization, which occurred before clamping and was revealed by a decrease of voltage on tracing. 15 patients showed early (within 4 min after clamping) changes and in 11 patients shunting led to the reversal of EEG anomalies in all cases but 2. The state of these 2 patients was worse after surgery, in one because of embolic problems, in the other (shunted 30 min after clamping) probably for hemodynamic reasons. 4 patients with early EEG changes, not shunted because of the short clamping time, had no neurological deficit. 7 patients, 2 of which were shunted, showed late (after 4 min) EEG changes. Only 1 nonshunted patient in this group awoke with a minor, transitory neurological complication. Moreover, EEG changes have been correlated with the preoperative clinical condition and with the presence, on angiography, of contralateral carotid lesions. Also, EEG findings have been correlated with the computed tomography data (in 71 cases) and with the values of interior carotid artery (ICA) back pressure (in 58 cases). No possibility to predict the tolerance to clamping appeared from these correlations. However, a relatively higher risk of intolerance to clamping in patients with contralateral ICA occlusion was noted.(ABSTRACT TRUNCATED AT 250 WORDS)
Prognosis of severe head injuries.
The authors have analyzed retrospectively a series of 288 consecutive patients with severe head injury observed between January, 1977, and May, 1980. Seventy-three patients were excluded as not being compatible with those of the International Data Bank. The remaining 215 patients complied with the definition of coma given by Jennett. All patients, after appropriate cardiopulmonary resuscitation, diagnostic measures, and, when required, surgical treatment, were managed in the Neurosurgical Intensive Care Unit with endotracheal intubation, controlled hyperventilation, mild dehydration, dexamethasone in standard doses, and sedation. The mortality rate was 39.5%. Of the survivors, 59.2% made a good recovery, 18.4% remained moderately disabled, 6.1% were severely disabled, and 1.5% were in a persistent vegetative state. The most reliable predictive criteria were: absence of brain-stem reflexes, neurological status, abnormal motor patterns, arterial hypotension, and presence of mass lesions. It is concluded that no sign has an absolute prognostic value when considered independently of its time course.
A multicenter study of ICU drug utilization.
As part of a view of hospital practice a sample of medical records of 15 intensive care units were analysed for the following items: reason for and origin of admission, age, sex, full pharmacological history, length of stay, clinical outcome, discharge diagnosis. Antibiotic therapy, steroid use for shock, problems of hemostasis, and cardiovascular drugs are areas where an active intervention appears to be specifically needed. Interhospital differences in diagnostic and general care criteria, documentation of inappropriate therapeutic practice, lack of reliable data registration gave occasion for an extensive discussion with clinicians leading to decisions on exclusion of drugs from hospital formularies, organization of information programs and of controlled clinical trials. The application of simple techniques of drug utilization review has proved a useful, inexpensive tool for creating favourable conditions for wide scale improvement of therapeutic practice.
[Role of fibrin formation processes in cerebrovascular diseases].
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Potential hazards of antifibrinolytic treatment in subarachnoid haemorrhage.
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