[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.

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.

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.

EGF stimulates lamellipod extension in metastatic mammary adenocarcinoma cells by an actin-dependent mechanism

Changes in lamellipod extension and chemotaxis in response to EGF were analysed for MTLn3 cells (a metastatic cell line derived from the 13762NF rat mammary adenocarcinoma). Addition of EGF produced a cessation of ruffling followed by extension of hyaline lamellipods containing increased amounts of F-actin at the growing edge. A non-metastatic cell line (MTC) derived from the same tumor did not show such responses. Lamellipod extension was maximal within 5 min, followed by retraction and resumption of ruffling. Maximal area increases due to lamellipod extension occurred at about 5 nM EGF. Chemotactic and chemokinetic responses, measured using a microchemotaxis chamber, were also greatest at 5 nM. Cytochalasin D inhibited EGF-stimulated responses including lamellipod extension, increases in F-actin in lamellipods, and chemotaxis. Nocodazole affected chemotaxis at higher concentrations but not EGF-induced lamellipod extension. We conclude that polymerization of F-actin at the leading edges of lamellipods is necessary for extension of lamellipods and chemotaxis of MTLn3 cells in response to EGF. The motility and chemotaxis responses of this metastatic cell line have strong similarities to those seen in well-characterized chemotactic cells such as Dictyostelium and neutrophils.

Cardiac and carotid structure in arterial hypertension and in hypertrophic cardiomyopathy

The aim of this study was to measure intima-media thickness (IMT) of the common carotid artery (CCA) in patients with hypertrophic cardiomyopathy (HCM) and in hypertensive patients with left ventricular hypertrophy (LVH). We studied 73 subjects: 20 normotensive healthy subjects as control group (I); 20 patients with essential hypertension without LVH (II); 20 hypertensives with LVH (III), and 13 normotensive patients with HCM (IV). Each subject underwent a complete echocardiographic and vascular ultrasonographic study in order to assess left ventricular parameters and the IMT at the level of the CCA. Left ventricular mass index (LVMI) was significantly higher in groups III and IV than in groups I and II (156 +/- 18 and 157 +/- 31 vs. 94 +/- 14 and 98 +/- 10 g/m2, respectively, p < 0.01), while IMT was significantly greater in group III but not in the others [0.88 +/- 0.04 vs. 0.61 +/- 0.03 (I), 0.64 +/- 0.03 (II) and 0.61 +/- 0.04 (IV) mm, p < 0.01]. The correlation between LVMI and IMT was statistically significant within all the hypertensive patients (r = 0.48, p < 0.01) but not in the HCM group (r = 0.17, p = NS). The hypertensive patients with LVH showed structural alterations (related to hemodynamic and humoral factors) both at cardiac and vascular level while in patients with HCM the cardiac alterations (due to a genetic disorder) were not associated with changes at the level of the large arteries.

Nicotinamide methylation in patients with cirrhosis

Methylation reactions play an important role in the transformation of endogenous and exogenous substances. Up to 85% of all transmethylation reactions occur in the liver. Several studies have shown that these metabolic processes are greatly influenced by the presence of hepatic diseases. We investigated the methylation of nicotinamide in 16 control subjects and in 29 patients with cirrhosis (19 Child A, 10 Child B). The basal serum value of N-methyl-nicotinamide was measured in all subjects. In seven controls and in nine patients with cirrhosis (5 Child A and 4 Child B), the serum levels and urinary excretion (5 and 24 h) of N-methyl-nicotinamide were also evaluated after oral administration of nicotinamide (1.5 mg/kg body weight). The basal serum levels of N-methyl-nicotinamide were significantly (p < 0.05) higher in patients with cirrhosis (Child A: median 34 ng/ml, 16th percentile 24, 84th percentile 61; Child B median 45, 16th percentile 34, 84th percentile 81) than in controls (median 22, 16th percentile 13, 85th percentile 28). After the nicotinamide load the urinary excretion and the time course of serum N-methyl-nicotinamide in cirrhosis were also higher (p < 0.05) than in controls (24 h urinary excretion = 66.2 mg +/- 5 S.D. in cirrhosis; 47.2 +/- 10.3 in controls) (area under the serum concentration versus time curve = 68 micrograms.ml-1.min-1 +/- 22 S.D. in cirrhosis; 32 +/- 15 in controls). In conclusion, our results show that cirrhosis does not impair the efficiency of nicotinamide methylation.

[Cardiac and vascular hypertrophy in juvenile borderline hypertension: echocardiographic and ultrasonographic study]

BACKGROUND

High resolution ultrasonography is a noninvasive technique that allows us to investigate the cardiovascular system, in particular the wall thickness and the lumen diameter of the arteries, with accuracy and reproducibility.

METHODS

We measured the intima-media thickness of the common carotid artery (CCA) and of its bifurcation (BIF) in 20 borderline hypertensive (age 24 +/- 4 years) and in 20 normotensive subjects (age 24 +/- 4 years), as a control group. Both carotid axes were scanned from different views (anterior, lateral, posterior) on a transversal and longitudinal section using a high resolution steerable linear array of 5 MHz. Carotid diameter and thickness were measured in the longitudinal section. CCA parameters were assessed 20 mm caudally to the flow divider.

RESULTS

In borderline patients blood pressure (147.8 +/- 10.5/90.7 +/- 6.6 mmHg) and left ventricular mass index (102.5 +/- 15.3 g/m2) were significantly higher than in normotensive subjects (blood pressure 120.5 +/- 11.5/78.0 +/- 5.4 mm Hg; left ventricular mass 90.5 +/- 14.3 g/m2). The intima-media thickness of both the CCA and BIF was significantly higher in borderlines than in normotensives (CCA 0.6 +/- 0.08 vs 0.4 +/- 0.05 mm, p < 0.001; BIF 0.7 +/- 0.08 vs 0.5 +/- 0.08, p < 0.001). In the whole population there was a statistically significant correlation between the carotid wall thickness and the left ventricular mass.

CONCLUSIONS

Our data show that ultrasonography provides direct evidence that in young borderline hypertensives the increased left ventricular mass is associated with vascular hypertrophy.

Ultrasonographic evaluation of cardiac and vascular changes in young borderline hypertensives

We measured the intima-media thickness of the common carotid artery (CCA) and of its bifurcation (BIF) in 20 borderline hypertensives (age 24 +/- 4 years) and in 20 normotensive subjects (age 23 +/- 6 years), as a control group. Both carotid axes have been scanned from different views on a transversal and longitudinal section. Carotid diameter and thickness were measured in the longitudinal section. CCA parameters were assessed 20 mm caudally to the flow divider. In borderline patients blood pressure (147.8 +/- 10.5/90.7 +/- 6.6 mm Hg) and left ventricular mass index (102.5 +/- 15.3 g/m2) were significantly higher than in normotensive subjects (blood pressure 120.5 +/- 11.5/78.0 +/- 5.4 mm Hg; left ventricular mass 90.5 +/- 14.3 g/m2, p < 0.01 and p < 0.05 respectively). The intima-media thickness of both the CCA and BIF was significantly higher in borderline hypertensives than in normotensives (CCA 0.6 +/- 0.08 vs. 0.4 +/- 0.05 mm, p < 0.01; BIF 0.7 +/- 0.08 vs. 0.5 +/- 0.08, p < 0.01). In the whole population there was a statistically significant correlation between the carotid wall thickness and the left ventricular mass.(ABSTRACT TRUNCATED AT 250 WORDS)

[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.

[Ultrasonographic evaluation of cardiac and vascular hypertrophy in patients with essential hypertension]

High resolution ultrasonography allows the accurate and reproducible measurement of thickness and lumen diameter of carotid arteries. We investigated Common carotid (CCA) and bifurcation intima-media thickness in 40 hypertensive patients, 20 without left ventricular hypertrophy (LVH) (age 42 +/- 10 years) and 20 with LVH (age 44 +/- 12 years), all free from other important cardiovascular risk factors. Both carotid axes were scanned from different views (anterior, lateral, posterior) on traversal and longitudinal section, using a high resolution steerable (HRS) 5.0 MHz linear array. Carotid diameter and thickness from longitudinal section were measured. CCA parameters were taken 20 mm caudally to flow divider. Using the B-mode as a guide we assessed LVH presence with M-mode technique when left ventricular mass index (LVMI) > or = 135 g/m2 for men and > or = 110 g/m2 for women. In hypertensive patients with LVH, left ventricular mass was significantly higher than in those without LVH (156 +/- 38 vs 98 +/- 10 g/m2, p < 0.01). Even blood pressure was significantly higher in hypertrophic group (172 +/- 21/108 +/- 9 vs 158 +/- 11/99 +/- 12 mmHg, p < 0.01), while there was no difference in serum glycemia, triglycerides, total and fractioned cholesterol levels. The intima-media thickness scanned in both CCA and bifurcation resulted significantly higher in hypertensives with LVH (CCA: 0.85 +/- 0.02 mm vs 0.65 +/- 0.02 mm; BIF: 0.93 +/- 0.04 mm vs 0.70 +/- 0.03 mm, p < 0.01). We also noticed a statistically significant correlation between carotid wall thickness and left ventricular mass index.(ABSTRACT TRUNCATED AT 250 WORDS)

[Continuous monitoring of O2 saturation in cerebral blood. A guide for the nursing of brain trauma patients in coma]

Manual ventilation is frequently performed by nurses to control increases in intracranial pressure (ICP) or during physiotherapy in head injured comatose patients. The effects of manual ventilation (n = 251) on ICP, cerebral perfusion pressure (CPP) and EEG have been studied in 18 mechanically ventilated patients. A fall in ICP was easily obtained but a fall in arterial blood pressure was often present at the same time. Thus a reduction in CPP resulted in 36% of occasions. Prophylactic boluses of thiopental (n = 67) before noxious stimuli obtained a fall in ICP in 99% of occasions but resulted in a decrease in CPP in 46%. The fall in ICP, due to the decrease in cerebral blood flow (CBF) by hypocapnia or metabolic depression and/or arterial hypotension, may be beneficial in hyperaemic brains but may precipitate cerebral hypoxia in ischaemic lesions. Relevant information about cortical metabolism (CMR) may be obtained from EEG monitoring by Cerebral Function Monitor but, unfortunately, no data about CBF are clinically available. The Authors suggest that the continuous monitoring of jugular bulb oxygen saturation (SjO2) may offer a clinically useful index of CBF adequacy to CMR. Findings from a preliminary study in 5 patients demonstrate that a severe decrease in SjO2 has been frequently caused by manual ventilation, hypothetically related to severe cerebral ischemia. High levels of SjO2 have been induced by endotracheal suction and physiotherapy, probably related to severe hyperemia. As prevention of ischaemic and hyperaemic insults is a major goal of treatment, the A. suggest that these undesirable effects of nursing might be avoided if nurses could take advantage of continuous monitoring of SjO2.

Prevalence of physiological valvular regurgitation in hypertensive patients: echocardiographic and color Doppler study

Since the advent of the Doppler color flow echocardiography, the presence of a small degree of insufficiency of the cardiac valves has been detected with relative frequency in structurally and functionally normal hearts. Data about this so-called 'physiological' regurgitation are presently available only in normotensive subjects and athletes. We therefore studied the prevalence of this phenomenon in a group of patients with essential hypertension compared to a population of normotensive subjects. To this purpose, a Doppler color flow echocardiographic study was performed in 130 essential hypertensive patients (72M/58F; age 44.2 +/- 13.5 years; BP 154.3 +/- 12.8/98.3 +/- 7.1 mm Hg) without any evidence of left ventricular hypertrophy or cardiopathy and in 100 normal subjects (59M/41F; age 41.2 +/- 14.8 years; BP 119.1 +/- 8.1/79.2 +/- 8.1 mm Hg). We conclude that in patients with essential hypertension the physiological regurgitant jets are present in one or more cardiac valves; moreover, the regurgitation of the mitral and aortic valve is found with more frequency than in the normotensive control group (36.1 vs. 27.0% and 17.7 vs. 11.0%, respectively). These data suggest that the increased afterload of the left ventricle may play an important role in the pathogenesis of even minor degree of insufficiency of the cardiac valves. As this finding does not appear to have a pathological relevance, the main clinical implication of this study is that it is not advisable to create a jatrogenic heart disease in the hypertensive patients routinely screened by the echo-Doppler technique.

Echocardiographic and ultrasonographic evaluation of cardiac and vascular hypertrophy in patients with essential hypertension

High-resolution ultrasonography is a noninvasive technique that allows to investigate the cardiovascular system, in particular the wall thickness and the lumen diameter of the arteries with accuracy and reproducibility. We measured the intima-media thickness of the common carotid artery (CCA) and of its bifurcation (BIF) in 40 patients with essential hypertension, 20 of them with left ventricular hypertrophy (LVH; age 42 +/- 10 years) and 20 without LVH (age 44 +/- 12 years); no other major cardiovascular risk factor was present in all the patients. Both carotid axes have been scanned from different views (anterior, lateral, posterior) on a transversal and longitudinal section using a high-resolution steerable linear array of 5.0 MHz. Carotid diameter and thickness were measured in the longitudinal section. CCA parameters were assessed 20 mm caudally to the flow divider. In patients with LVH, blood pressure (172 +/- 21/108 +/- 9 mm Hg) and left ventricular mass index (156 +/- 38 g/m2) were significantly (p < 0.01) higher than in patients without LVH (blood pressure: 158 +/- 11/99 +/- 12 mm Hg; left ventricular mass index: 98 +/- 10 g/m2), while there was no difference in serum glycemia, triglycerides, total and fractioned cholesterol levels. The intima-media thickness of both the CCA and BIF was significantly higher in the hypertensives with LVH (CCA: 0.85 +/- 0.02 vs. 0.65 +/- 0.02 mm; BIF: 0.93 +/- 0.04 vs. 0.70 +/- 0.03 mm, p < 0.01). There was a statistically significant correlation between the carotid wall thickness and the left ventricular mass index.(ABSTRACT TRUNCATED AT 250 WORDS)