Modified Dental Anxiety Scale: validation of the Italian version

AIM

Anxiety is a relevant problem in dental practice. The Modified Dental Anxiety Scale (MDAS) is a brief, simple questionnaire consisting of five questions with a total score ranging from 5 to 25, the Italian version of which is not available yet. The aim of the study was to provide an Italian version of the MDAS and check its reliability in oral surgery, which is a major cause of dental anxiety due to the expected perception of pain and suffering.

METHODS

The Italian version of the test was administered to 230 patients (98 male and 132 female patients, ages 14-88 years) undergoing oral surgery. Further recorded data were: American Society of Anaesthesiologists physical status classification (ASA-PS), frequency of visiting the dentist and any previous distressing experiences in dental or medical setting.

RESULTS

The internal consistency of the test was high, with a Cronbach's alpha=0.92. The MDAS score was significantly higher in females (P<0.0001) and in patients with previous distressing experiences in medical and/or dental settings (P<0.0001); the correlation with age (P=0.01) and frequency on visiting the dentist (P=0.02) were also significant.

CONCLUSIONS

The patients' selection (oral surgery only) may be a limit of the study, which might not provide an estimation of anxiety prevalence in the general dental population; however our result agree with those of studies performed in other Countries in the generic population, suggesting the absence of major differences with respect to the surgical setting and show the reliability and manageability of the Italian version of MDAS.

Modified dental anxiety scale: validation of the italian version

AIM

Anxiety is a relevant problem in dental practice. The Modified Dental Anxiety Scale (MDAS) is a brief, simple questionnaire consisting of five questions with a total score ranging from 5 to 25, the Italian version of which is not available yet. The aim of the study was to provide an Italian version of the MDAS and check its reliability in oral surgery, which is a major cause of dental anxiety due to the expected perception of pain and suffering.

METHODS

The Italian version of the test was administered to 230 patients (98 male and 132 female patients, ages 14-88 years) undergoing oral surgery. Further recorded data were: American Society of Anaesthesiologists physical status classification (ASA-PS), frequency of visiting the dentist and any previous distressing experiences in dental or medical setting.

RESULTS

The internal consistency of the test was high, with a Cronbach's alpha=0.92. The MDAS score was significantly higher in females (p<0.0001) and in patients with previous distressing experiences in medical and/or dental settings (p<0.0001); the correlation with age (p=0.01) and frequency on visiting the dentist (p=0.02) were also significant.

CONCLUSIONS

The patients' selection (oral surgery only) may be a limit of the study, which might not provide an estimation of anxiety prevalence in the general dental population; however our result agree with those of studies performed in other Countries in the generic population, suggesting the absence of major differences with respect to the surgical setting and show the reliability and manageability of the Italian version of MDAS.

Validation of visual analogue scale for anxiety (VAS-A) in preanesthesia evaluation

BACKGROUND

Anxiety is a relevant but still underscored perioperative problem. The Visual Analogue Scale for Anxiety (VAS-A) seems to be effective, fast and manageable, but has not been fully validated yet. The aim of this study is to validate VAS-A comparing it to, Corah's Dental Anxiety Scale (CDAS) Spielberger's State Trait Anxiety Inventory (STAI) and Beck Depression Inventory (BDI).

METHODS

One hundred consecutive patients (38 males and 62 females, median age 49 years) submitted to oral surgery filled out the VAS-A, CDAS, STAI forms Y1 and Y2, and BDI at preoperative examination; the order of administration of tests was randomized.

RESULTS

VAS-A score was significantly correlated to CDAS (P<0.0001), STAI-Y1 (P<0.0001), STAI-Y2 (P<0.002) but not to BDI (P=0.18). ROC curve analysis suggested VAS-A equal to 46 mm as threshold for anxiety when using STAI Y1 equal to 40 as reference cutoff.

CONCLUSION

Our study confirms that VAS-A is a reliable indicator of preoperative anxiety and may detect patients with depressive symptoms also. Values of VAS-A around 50 mm are a reliable threshold for a clinically meaningful level of preoperative anxiety.

Conscious sedation with diazepam and midazolam for dental patient: priority to diazepam

AIM

The aim of this paper was to determine whether the use of midazolam is a better technique than the use of diazepam, in relation with the definition of conscious sedation in dentistry.

METHODS

Eighty-eight patients undergoing oral surgery were divided into 2 groups in which the sedation was randomly achieved with equipotent cumulative doses of diazepam and midazolam, up to a maximum dose of 8 and 4 mg respectively. Patient's tranquillity was assessed after every dose, using a visual analogue score to ten points and the sedation was evaluated as mild, moderate or deep. Blood pressure, heart rate and SpO2 were also recorded. Psychomotor conditions, by Newman test, and the incidence of amnesia and the patient's satisfaction, by telephone interview, were both evaluated.

RESULTS

The number of patients who reached maximum subjective tranquillity was greater already after the third dose of diazepam. The average scores of tranquillity were higher after diazepam. Patients treated with diazepam experienced a higher incidence of mild sedation, patients treated with midazolam a higher incidence of moderate and deep sedation. In patients treated with midazolam blood pressure, heart rate and SpO2 were lower. Postoperative recovery was similar in the 2 groups. After midazolam patients experienced greater amnesia for local anesthesia and drowsiness. Satisfaction was high with both treatments.

CONCLUSION

The study shows that sedation with diazepam is more in line with the definition of conscious sedation in dentistry. Diazepam guarantees the persistence of consciousness and maximum subjective tranquillity levels. The recovery and satisfaction were comparable in the 2 groups.

Acupuncture versus valproic acid in the prophylaxis of migraine without aura: a prospective controlled study

BACKGROUND

The pharmacologic treatment of migraine still remains below the expectations. The aim of this study is to compare the effectiveness of traditional acupuncture and valproic acid in migraine prophylaxis.

METHODS

A prospective, controlled study was performed in 100 patients affected by migraine without aura lasting for over one year. The patients were stratified for sex and randomly divided into two groups of 50 patients each. Patients belonging to Group A (acupuncture) were submitted to 20 sessions of acupuncture, while patients belonging to Group V valproate) were administered Valproic acid (Depakin Chrono®) at a dose of 600 mg/day; 10 mg Rizatriptan wafers were allowed as needed to treat the attacks. The Midas Index (MI) and pain intensity (PI, by VAS) were recorded before treatment (T0), at three (T1) and six (T2) months; a six-point scale Pain Relief score (PRS), the Rizatriptan intake and adverse events were recorded at T1 and T2.

RESULTS

Eighty-two out of 100 patients completed the study (9 dropouts in each group). In both groups the MI improved at T1 and T2 (P<0.0001). Pain intensity was better at T1 in group V (P<0.0001), but PI and PRS (P=0.02) as well as rizatriptan intake (P=0.001) were better in group A at T2. The rate of adverse events was 47.8% in group V and 0% in group A.

CONCLUSION

Our data show a lower pain intensity and lower Rizatriptan intake at six-months follow-up with no adverse events in acupuncture patients compared to those treated with valproic acid.

Comparison by means of bispectral index score, between anxiolysis induced by diazepam and sedation induced by midazolam

AIM

Bispectral Index Score (BIS) is an objective tool to assess sedation depth. Benzodiazepines have different pharmacological profiles and diazepam may be safer than midazolam in this setting. The aim of this study was to compare BIS values observed during anxiolysis after diazepam versus sedation after midazolam.

METHODS

Thirty-six patients were randomly assigned to 3 groups: group 1 was treated with i.v. diazepam, groups 2 and 3 with iv midazolam 1 and 3 mg, respectively. Sedation was monitored clinically and by means of BIS. BIS values were evaluated as area under the curve (AUC) and compared by variance analysis. The statistical comparison of other data was performed by variance analysis or, alternatively, the χ2 according to Yates. The statistical significance was indicated by P values <0.05.

RESULTS

AUC values were significantly lower after midazolam when compared to AUC values registered in diazepam treated patients; 22.6% of the group 3 patients showed BIS values <80, versus 0.4% of group 1 patients.

CONCLUSION

Diazepam has a safer profile, with BIS values and clinical conditions according to the definition of minimal and/or moderate sedation. Diazepam represents the safer drug for anxiety management in dentistry, because regularly produces a state of sedation during which verbal contact with the patient is maintained and carry a margin of safety wide enough to render loss of consciousness unlikely.

Toward the validation of visual analogue scale for anxiety

Anxiety is a relevant problem in dental practice. The Visual Analogue Scale for Anxiety (VAS-A), introduced in dentistry in 1988, has not yet been validated in large series. The aim of this study is to check VAS-A effectiveness in more than 1000 patients submitted to implantology. The VAS-A and the Dental Anxiety Scale (DAS) were administered preoperatively to 1114 patients (459 males and 655 females, age 54.7 ± 13.1 years). Statistical analysis was conducted with Pearson correlation coefficient, the receiver operating characteristic (ROC) curve, and McNemar tests. A close correlation between DAS and VAS-A was found (r  =  0.57, P < .0001); the VAS-A thresholds of dental anxiety and phobia were 5.1 and 7.0 cm, respectively. Despite a significant concordance of tests in 800 cases (72%), disagreement was found in the remaining 314 cases (28%), and low DAS was associated with high VAS-A (230 cases) or vice versa (84 cases). Our study confirms that VAS-A is a simple, sensitive, fast, and reliable tool in dental anxiety assessment. The rate of disagreement between VAS-A and DAS is probably due to different test sensitivities to different components of dental anxiety. VAS-A can be used effectively in the assessment of dental patients, using the values of 5.1 cm and 7.0 cm as cutoff values for anxiety and phobia, respectively.

Comparison between two regional anaesthesia techniques performed by inexperienced operators: the Gow-Gates block versus the Kenneth Reed block

AIM

The aim was to compare the efficacy of Kenneth Reed and Gow-Gates inferior alveolar nerve blocks when performed by an inexperienced operator.

METHODS

A group of 60 patients was randomised into two groups. One group had the Kenneth Reed technique used to administer an inferior alveolar nerve block whilst the other received the Gow-Gates technique. The efficacy of nerve block produced was evaluated both clinically and by electric pulp tester. MRI examination was undertaken to determine the spread of local anaesthetic.

RESULTS

There were no significant differences in success rate of anaesthesia between groups. The failure rate for the Gow-Gates technique was 16.6%, whilst the failure rate for the Kenneth Reed technique was 23.3%. Time to onset was less with the Kenneth Reed technique. MRI examination showed the solution was more widely distributed after the Kenneth Reed block had been used.

CONCLUSIONS

Our research has demonstrated that the Kenneth Reed technique is equally effective at producing anaesthesia of the inferior alveolar nerve. Compared with conventional techniques there is a lower incidence of positive aspiration and potential for lower morbidity as the local anaesthetic is deposited further from the neurovascular bundle than when deposited near the mandibular foramen as in most conventional Inferior Alveolar Nerve Block techniques.

Patients appreciation for information on anesthesia and anxiolysis in dentistry

AIM

The research regards information on anesthesia to patients undergoing oral surgery. Every patient evaluated the information received at the end of the preoperative visit and in the postoperative period.

METHODS

One hundred-fifty dental patients were asked about the most appreciated information received in the preoperative visit on the anxiolytic technique, local anesthesia and treatment of the perioperative pain. Afterwards the patients had to report on their reaction to the content of the preoperative visit and information quality. On a phone interview they had to evaluate their appreciation of the anxiolytic technique, their perception during loco-regional anesthesia and incidence of pain and edema.

RESULTS

The most appreciated details were those on the intervention, pharmacologic treatment, postoperative complicances, postoperative pain and operative competence; less appreciated were those on loco-regional anesthesia, duration of the intervention, anxiolytic techniques, hospital reception and permanence in the hospital. Ninety-eight percent of the patients considered to have been adequately informed on a context judged to be extraordinary (99.3%), 96.6% indicated the information as necessary, 98.6% appreciated the treatment of the intraoperative and postoperative (99.3%) pain and 99.3% the anxiolytic treatment. On the telephone interview, 100% of patients expressed satisfaction for the experienced intraoperative tranquillity, 91.3% complained for not having received in the past a similar preoperative visit, 99.3% wished a diffused application of the information. The loco-regional anesthesia was associated to psychological detachment in 84% of the cases and the incidence of postoperative pain was of 36%.

CONCLUSION

The information on the anxiolytic techniques, loco-regional anesthesia, treatment of perioperative pain and postoperative distress was enthusiastically accepted and albeit initially induced feelings of astonishment resulted to be appreciated and preferred in the whole of the patients.

Myotonia congenita and regional anaesthesia with peripheral nerve stimulation: a case report

Myotonia congenita is a rare disorder caused by a defect in the skeletal muscle chloride channel function, which may cause sustained membrane depolarisation. We report a case regarding a 52-year-old man affected by this muscular pathology and scheduled for shoulder surgery that was performed under sedation and peripheral nerve block. The international literature does not elucidate clear preference toward a particular anaesthesia technique, but we believe that in this setting, regional anaesthesia and complete monitoring should be preferentially utilized when possible. In any case, the anaesthesia plan should be prudent and avoid exposure to known dangerous anaesthetics.

Electronic dental anaesthesia for third inferior molar surgery

AIM

The aim of this study was to evaluate the efficacy of Electronic Dental Anaesthesia (EDA) for third molar surgery.

METHODS

Third molar extraction under regional anaesthesia (inferior alveolar and buccal nerve blocks) was performed in 2 groups of 30 patients each: group 1 = controls, group 2 = EDA treatment. Anxiety and pain level were reported by means of Visual Analogue Scale, postoperative pain description with the McGill Pain Questionnaire. A postoperative phone interview to all patients was made. Computerized randomization was performed; values expressed as mean+/-SD, data comparison evaluated by means of ANOVA and chi squared, statistical significance indicated by P values <0.05.

RESULTS

Features of the patients and surgical interventions were similar. EDA has determined lower pain level; moreover, the control patients has shown higher values of blood pressure and heart frequency. Phone interview has reported no amnesia about the perioperative events. A smaller number of EDA treated patients has reported pain during needle prick and/or intraoperatively; 80% of the EDA treated patients has reported a good opinion about the treatment, 93% of the patients would repeat the treatment, if needed.

CONCLUSION

EDA is a complementary analgesic technique for dental surgery. Cardiovascular changes, frequently observed during third molar extraction, were not present in the EDA treated patients. These data confirm that EDA is able to modify the physiologic responses to stressful events, blunting the adrenergic upset, maybe by means of an analgesic action on A, fiber and an increase of endorphins' central level. These results underline that the complementary use of EDA in the third molar extraction may be better than regional anaesthesia alone.

Spectral entropy assessment with auditory evoked potential in neuroanesthesia

OBJECTIVE

The assessment of the level of anesthesia is a very hard task, since no gold standard has stood out in the past three decades. Middle Latency Auditory Evoked Potential (MLAEP) is one of the most popular neurophysiological tools for anesthesia monitoring. Recently, Spectral Entropy (SpEn) has been introduced: it provides two different parameters, State Entropy (SE) and Response Entropy (RE). The aim of this prospective study is to check SpEn end-point, comparing it to MLAEPs in neurosurgical anesthesia.

METHODS

Twenty patients submitted to elective supratentorial neurosurgery for removal of a temporal-parietal meningioma were included in the study. SpEn and MLAEPs were simultaneously monitored using the M-entropy module S/5 (GE Health Care, Helsinki, Finland) and Alaris Medical System AEP-ARX index monitor (AAI) (Kidemosevej, Denmark), respectively.

RESULTS

Four thousand and sixty four data points of SE, RE and AAI were recorded and ROC curves comparing AAI to RE and SE showed a highly significant (p<0.0001) area under the curve. The RE and SE cut-off values (showing maximal sensitivity with maximal specificity) to discriminate anesthesia from awake or consciousness sedation were 61 and 58, respectively. However, in a group of data points, low AAI was associated to high SpEn (577 data points for RE and 770 for SE) and vice versa (31 data points for RE and 43 for SE). The prediction probability for SE was 0.977 and for RE was 0.968.

CONCLUSIONS

Our results suggest that SpEn is as effective as AAI.

SIGNIFICANCE

Our results show that SpEn is able to discriminate between the levels of wakefulness and surgical anesthesia. However, the meaning of data showing a discrepancy between AAI and SpEn is not yet clear and calls for further study.

Bispectral Index in the sedation with intranasal midazolam and intravenous diazepam in dental practice

AIM

Aim of this study was to assess by clinical evaluation and by Bispectral Index (BIS) the tranquillizing properties of diazepam injected intravenously, and midazolam by intranasal route according to the body weight in dental patients.

METHODS

A group of 34 patients undergoing implantology were divided at random into 2 groups of 17. They were evaluated physically, clinically and psychologically. The psychomotor activity was measured by the Newman's test. Preoperative anxiety was treated with chlordemethyldiazepam (CHDDZ) per os, administered before induction of conscious sedation. In the first group, conscious sedation was accomplished by induction with titrated doses of i.v. diazepam, and in the second group with 0.1 mg/kg of intranasal midazolam. BIS values were analysed as Area Under the Curve (AUC).

RESULTS

The AUC BIS values after CHDDZ presedation were overlapping in both groups. AUC after midazolam decreased after induction of the conscious sedation (P<0.05), during anesthesia (P<0.01) and during intervention (P<0.01) compared to the diazepam treatment. In the midazolam group the BIS values were on average lower than 90, while in the diazepam group they were on average higher than 95 (P<0.01). The psychomotor recovery was more impaired after midazolam.

CONCLUSIONS

The study shows that nasal route ensures the quick absorption of midazolam as revealed during the first 3 min from drug administration. The depressant effect of midazolam increased as a function of time, reaching the highest levels during intervention. The results suggest that midazolam is endowed with sedative effects which may compromise the state of consciousness of the patient and be incompatible with the definition of conscious sedation in dentistry.

Myofascial pain mimicking radicular syndromes

Myofascial pain is very often underscored and misunderstood in clinical practice. In many cases the localization of myofascial pain may resemble other diseases, such as radicular syndromes (e.g., low back pain from herniated disc) and even diseases of internal organs (e.g., angina pectoris, bowel diseases or gynaecological disturbances). In pain clinics one can routinely see patients with myofascial painful disorders showing a radicular topography and normal CT and MRI: as a consequence, when vertebral abnormalities are present on CT or MRI, it should be checked whether the cause of pain is radicular, myofascial, or both. On the other hand, the conventional approach to painful disorders may lead to errors and wrong diagnosis, depending on several factors: a) pain is often considered a symptom of an organic disease; b) the diagnosis is usually directed towards the structural cause of pain only; c) the functional components of the suffering patient are underscored; d) the site of pain may introduce some bias. When the latter is concerned, it is usually admitted that a neck pain may depend on muscle contraction (e.g. torticollis), while such a cause is less commonly admitted for leg, where the attention is first directed towards the sciatic nerve; myofascial origin of pain is even less considered in abdominal or pelvic painful disorders, where patients with no structural detectable diseases are often considered as neurotic and referred to the psychiatrist. The reason for this topographical dependence of diagnosis lies in the conventional attitude to focus on the most relevant and frequent organic diseases, thus introducing a bias with relevant epistemological implications.

Comparative efficacy and side effects of the treatment of euthyroid goiter with levo-thyroxine or triiodothyroacetic acid

Euthyroid goiter is usually treated with TSH-inhibitory doses of levo-T(4) (L-T(4)). Because triiodothyroacetic acid (TRIAC) decreases TSH levels, the following study was perfomed: 36 euthyroid goitrous female patients (no cancer or chronic thyroiditis) were randomized to TRIAC (19.6 micro g/kg) (n = 19) or L-T4 (1.7 microg/kg) (n = 17) treatment during 11 months. Goiter volume; lumbar and femoral bone mineral density; serum osteocalcin; deoxypyridinoline; TSH; free T(4); total, high-density lipoprotein, and low-density lipoprotein cholesterol; and triglycerides were measured before and after the study period. Student's t test and chi(2) analysis were performed. TSH values (microunits per milliliter) in the TRIAC and L-T(4) groups were: 1.91 +/- 0.6 (basal) and 0.180 +/- 0.1 (after) and 2.1 +/- 2.5 (basal) and 0.180 +/- 0.3 (after), respectively. Thyroid volume decreased 37.9 +/- 35.4% in the TRIAC patients and 14.5 +/- 39.5% in the L-T(4) group (P = 0.069). Forty-two percent of the goiters with TRIAC reduced more than 50% their initial volume vs. 17.7% with L-T(4) (P = 0.15). With TRIAC, patients experienced fewer side effects. No differences in the changes of bone mineral density, serum deoxypyridinoline, osteocalcin, or the lipid profile were observed between both groups. The present results show that TRIAC is more effective than L-T(4) in the reduction of goiter size, with comparable effects on peripheral parameters.

An experimental model of myasthenia myopathy

Normal and thymectomised rabbits been have immunized by means of a thymic extract emulsified with Freund's Complete Adjuvant. The experiment was conducted over a three month period, in order to reproduce an experimental model of chronic myasthenia. During this period immunological, electromyographic and histologic studies were undertaken. Typical findings of partial neuromuscular block were invariably obtained from all the non thymectomized animals, while such signs were constantly absent both in non-treated control rabbits and in the immunized thymectomized ones. This neuromuscular block was intermittent. The compromised neuromuscular conduction was associated to an histological pattern of autoimmune myopathy. Evidence was put on antibodies directed against the thymus, muscular and nervous tissue. The results indicate the important role of the thymus gland both in altering conduction at the neuromuscular junction level and causing histopathologic muscle lesions.

Propofol 1% and propofol 2% are equally effective and well tolerated during anaesthesia of patients undergoing elective craniotomy for neurosurgical procedures

BACKGROUND

The 2% formulation of the intravenous anaesthetic agent, propofol (Diprivan), delivers half the amount of lipid compared with the original 1% formulation. This may provide an acceptable alternative for patients who have an impaired ability to metabolise lipids.

METHODS

This study was a multicentre, randomised, open comparison of parallel groups. Seventy-three adult patients undergoing elective craniotomy in neurosurgery were randomised to receive either propofol 1% (10 mg/ml) or propofol 2% (20 mg/ml) for induction and maintenance of anaesthesia.

RESULTS

Analysis of induction time (199 s, 1%; 202 s, 2%; p > 0.05) and induction dose (1.13 mg/kg, 1.12 mg/kg; p > 0.05) shows that propofol 1% and propofol 2% are pharmacodynamically equivalent. Both formulations were similar regarding overall administration rates, recovery times, haemodynamic variables and tolerability. Plasma triglyceride levels, were lower in the propofol 2% group compared with the propofol 1% group, and significantly lower (p < 0.05) from 1 to 4 hours after induction.

CONCLUSIONS

We conclude that propofol 2% is as effective and as well-tolerated as propofol 1% for anaesthesia and is an acceptable alternative to propofol 1% in patients undergoing elective craniotomy in neurosurgery. The lower lipid load suggests it may be of particular benefit to patients with disorders of lipid metabolism.

Relationship between central venous pressure and bioimpedance vector analysis in critically ill patients

OBJECTIVE

To assess the relationship between central venous pressure values and bioelectrical impedance vector analysis (BIVA), which may be used as complementary methods in the bedside monitoring of fluid status.

DESIGN

Cross-sectional evaluation of a consecutive sample.

SETTING

Intensive care unit of a university hospital.

PATIENTS

One hundred and twenty-one consecutive Caucasian, adult patients of either gender, for whom routine central venous pressure measurements were available.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Central venous pressure values and impedance vector components (i.e., resistance and reactance) were determined simultaneously. Total body water predictions were obtained from regression equations according to either conventional bioimpedance analysis or anthropometry (Watson and Hume formulas). Variability of total body water predictions was unacceptable for clinical purposes. Central venous pressure values significantly and inversely correlated with individual impedance vector components (r2 = .28 and r2 = .27 with resistance and reactance, respectively), and with both vector components together (R2 = .31). Patients were classified in three groups according to their central venous pressure value: low (0 to 3 mm Hg); medium (4 to 12 mm Hg); and high (13 to 20 mm Hg). Three BIVA patterns were considered: vectors within the target (reference) 75% tolerance ellipse (normal tissue hydration); long vectors out of the upper pole of the target (dehydration); and short vectors out of the lower pole of the target (fluid overload). The agreement between BIVA and central venous pressure indications was good in the high central venous pressure group (93% short vectors), moderate in the medium central venous pressure group (35% normal vectors), and poor in low central venous pressure group (10% long vectors).

CONCLUSIONS

Central venous pressure values correlated with direct impedance measurements more than with total body water predictions. Whereas central venous pressure values >12 mm Hg were associated with shorter impedance vectors in 93% of patients, indicating fluid overload, central venous pressure values <3 mm Hg were associated with long impedance vectors in only 10% of patients, indicating tissue dehydration. The combined evaluation of intensive care unit patients by BIVA and central venous pressure may be useful in therapy planning, particularly in those with low central venous pressure in whom reduced, preserved, or increased tissue fluid content can be detected by BIVA.

[General anesthesia with remifentanil in a case of "sleep apnea syndrome"]

The authors report the case of a patient suffering from central sleep apnea (CSA) who underwent neurosurgery for ventriculo-peritoneal derivation under general anesthesia. Given the risk of postoperative hypoventilation in CSA, intraoperative anesthesia was induced using remifentanyl, an opiate with a plasma half-life of less than 5 minutes. Propofol (2 mg/kg) and remifentanyl at a dose of 0.5 microgram/kg was used during induction. The patient was curarised with vecuronium bromide, intubated and ventilated with a mixture of O2/N2O. During the operation, remifentanyl was administered as a continuous infusion at a starting dose of 0.2 microgram/kg/min, subsequently modified according to changes in arterial pressure and heart rate. At the end of surgery, which lasted approximately 120", decurarisation was carried out using prostigmin, and the infusion of remifentanyl was suspended, together with N2O. Reawakening times were recorded. Extubation took place 8' and 30" after the suspension of remifentanyl. Postoperative monitoring of SpO2 continued for 1 h and blood-gas analysis was satisfactory. No hypoventilation episodes were reported throughout the postoperative period and the patient was discharged from hospital after 7 days. The authors consider that remifentanyl should be the drug of choice to guarantee intraoperative analgesia in patients suffering from CSA requiring general anesthesia.

Auditory and somatosensory evoked potentials in coma following spontaneous cerebral hemorrhage: early prognosis and outcome

The aim of this study was to check the prognostic power of auditory brain-stem responses (ABRs) and somatosensory evoked potentials (SEPs) in coma following spontaneous cerebral hemorrhage. Seventy patients comatose following subarachnoidal or hypertensive hemorrhage were submitted to ABR and SEP recordings during the acute phase of clinical course. Twenty-one patients survived (30%), two remained vegetative (2.9%) and 47 died (68.1%). The Glasgow Coma Score (GCS) was significantly related to the outcome (P < 0.001), but showed a low sensitivity, since about 50% of patients with GCS = 5-8 died or remained vegetative. ABRs and SEPs showed a much closer correlation with outcome (P < 0.001): their combined use allowed there to be a sensitivity of 96%, a specificity of 90% and a predictive power of 96%; the relative risk of poor outcome in patients with at least one abnormal modality was equal to 223 times the one for patients with normal evoked potentials. Moreover, in surviving patients a significant relationship appeared to exist between abnormalities of SEPs during the acute phase and the severity of disability. Our results confirm the prognostic effectiveness of short latency evoked potentials in cerebral hemorrhage: they are far superior to clinical data, being able to yield a marked decrease of falsely optimistic predictions.

99mTc-HMPAO SPECT in the diagnosis of brain death

OBJECTIVE

To evaluate the effectiveness of single proton emission tomography (SPECT) with 99mTc-HMPAO in the diagnosis of brain death (BD).

DESIGN

Prospective study in comatose and brain-dead patients.

SETTING

Neurologic ICU.

PATIENTS AND METHODS

Fifty comatose patients (age range: 10 days-75 years) were submitted to SPECT study. In 21 of them (42%) reversible factors (e.g., influence of drugs affecting the central nervous system) were present. Thirty-eight patients were clinically brain-dead, while the remaining 12 were tested both in pre-terminal conditions and after the clinical onset of BD.

INTERVENTIONS

Brain SPECT following i.v. injection of 99mTc-HMPAO (300-1100 MBq), using a 4-headed gamma-camera (20 min, 360 degrees, 88 images).

MEASUREMENTS AND RESULTS

All patients tested in pre-terminal conditions showed preserved brain perfusion. Two of them had flat EEGs despite the absence of any reversible cause of coma; three patients survived, but remained in persistent vegetative states. SPECT confirmed the diagnosis of BD in 45 out of 47 patients (95.7%), clearly showing the arrest of brain perfusion (picture of "empty skull"); in two clinically brain-dead children (aged 10 days and 12 months, respectively) weak perfusion of the basal ganglia, thalamus and/or brain stem was still present, precluding the diagnosis of BD; both of them died a few days later.

CONCLUSIONS

Our results confirm the reliability of SPECT in the diagnosis of BD. A problem arises about its effectiveness in brain-dead children, but this seems to be a matter of definition of BD and cerebral viability, rather than a limit of SPECT.

Assessment of brain perfusion in coma and comparison between SPECT and CT scan data: preliminary report

In this study we submitted 24 comatose patients (Glasgow Coma Score <8) to Single Photon Emission Tomography (SPECT) during the clinical course of coma to verify its utility and the relationship between SPECT and CT scan data. SPECT was recorded following i.v. injection of Xe-133 in 17 patients and of Tc-99m-HMPAO or Tc-99m-ECD in the remaining 7. SPECT data recorded during the acute phase of coma did not show a clear correlation between cerebral blood flow (CBF) and outcome. SPECT and CT scan detected abnormalities in the same areas in 6 cases (25%); 6 patients (25%) with focal CT-scan lesions showed no focal CBF alterations in the same regions; conversely, in the remaining 12 cases (50%) SPECT disclosed severe perfusion abnormalities where no lesions were detectable on CT-scan. SPECT allowed us to recognize different regional flow patterns, such as absolute or relative hyperemia or oligoemia, which could not be checked with other means, thus improving patient's management. Apart from cerebral ischemia, there was no relationship between lesions on CT-scan and flow pattern. Our preliminary results suggest that SPECT can improve both the knowledge of patient's neurological conditions and management in comparison to the use of only CT scan.

Regional cerebral blood flow (rCBF) in migraine during the interictal period: different rCBF patterns in patients with and without aura

The aim of this study was to evaluate the rCBF (133Xe clearance method) in migrainous patients free from attack. Fifty patients suffering from migraine without aura (group M) and 20 suffering from migraine with aura (group MA) (age range 20-50 years) were submitted to 32 channel rCBF mapping during the interictal period. The rCBF data of patients were compared with those obtained from 60 healthy control subjects (group C) and 21 patients suffering from tension-type headache (group TH). The mean (average of all channels) rCBF values were: group M = 70.5 +/- 13.7 ml/100g/min; group MA = 56.6 +/- 11.4 ml/100g/min; group C = 62.3 +/- 8.3 ml/100g/min; group TH = 62.1 +/- 8.4 ml/100g/min (F = 11.93; p < 0.001). As expected, patients belonging to group TH had a normal rCBF. The mean rCBF of group M was significantly higher than that of groups C and TH, while in group MA it was significantly lower than in groups C and TH. Group M showed a diffuse hyperemia, while group MA showed rCBF values significantly lower than normal in posterior regions, according to aura. Our results suggest that: (a) the rCBF pattern in migrainous patients is different from that in both controls and TH patients, even during the interictal period; (b) patients suffering from migraine with and without aura are two distinct subpopulations with opposite rCBF deviations.

[Clinico-instrumental assessment of swallowing in head injury rehabilitation]

During the phase of clinical and neurological stability following head injury, the recommencement of oral nutrition indicates not only the recovery of normal physiological function but is also closely correlated to the overall rehabilitation process and therefore represents a complex source of valuable stimuli in the context of a therapeutic and rehabilitation programme of the cognitive functions themselves. Before any attempt of oral feeding it is important to make a full clinical and instrumental evaluation of the swallowing process in order to diagnose any dysphagic problems and to assess the correct feeding method for the patient so as to avoid the severe sequelae caused by the penetration of food into the air paths.

Multimodality evoked potentials (auditory, somatosensory and motor) in coma

Auditory brainstem responses (ABRs) have proved to be significantly related to outcome, both in severe head injury and brain hemorrhage. Nevertheless, the usefulness of ABR is limited by the anatomic extent of the investigated pathways. The combined use of ABRs and somatosensory evoked potentials (SEPs) improves the outcome prediction in comparison to the use of only one modality. It mainly decreases the rate of false negatives, since patients with severe hemispheric damage sparing the brain stem may have a poor outcome despite normal ABRs. The use of motor evoked potentials (MEPs) from magnetic transcranial stimulation is also significantly related to outcome: it appears to be far superior to the clinical evaluation of motor responses, while the combined use of MEPs and SEPs gives a new opportunity of checking sensorimotor dysfunction. ABRs and SEPs may also be useful tools in the confirmation of brain death, the kernel of which is the assessment of brainstem death: they allow to check lemniscal pathways, which cannot be properly evaluated by clinical examination, and provide an objective confirmation of absence of brain stem activity.

EEG monitoring of carotid endarterectomy with routine patch-graft angioplasty: an experience in a large series

Four hundred and thirty-nine carotid endarterectomies (CEAs) with routine use of patchgraft angioplasty were performed in 375 patients; the indwelling shunt was used only in patients showing clamp-related EEG abnormalities. Five patients showed EEG abnormalities just after head positioning, which reversed after removal of head hyperextension; three cases suffered EEG flattening due to severe bradycardia or cardiac arrest before carotid clamping, which promptly reversed after treatment. Clamp-related EEG abnormalities appeared in 106 operations (24.2%) and all reversed after the insertion of the indwelling shunt; patients with occlusion of the contralateral internal carotid artery showed a 68.8% rate of EEG clamp-related changes. The short term follow-up (one month after the operation) showed six minor strokes with complete recovery (1.37%), one intraoperative stroke (0.23%), three delayed major strokes (0.69%) and three neurological deaths (0.69%). The long-term follow-up over an average of 42 months showed a 3.7% rate of relevant neurological complications (ie permanent deficits + death) and a 3.16% rate significant restenosis or occlusion of the operated carotid artery. Our results show that the routine use of EEG monitoring and patch-graft angioplasty allow to perform CEAs with a very high degree of safety, improving the clinical course of the disease.

Sensorimotor central conduction time in comatose patients

Motor evoked potentials (MEPs) following magnetic stimulation were recorded in 22 patients comatose as a result of head injury (13 cases), stroke (7 cases) or anoxia (2 cases). Somatosensory evoked potentials (SEPs) from median nerve were recorded as well in 19 cases in the same session. Thirteen patients died or remained vegetative (59.1%), 3 were severely disabled (13.6%) and 6 showed a good recovery (27.3%). MEPs were significantly related to the outcome; they appeared to be a more accurate prognostic indicator than the Glasgow Coma Scale (GCS). However, 1 out of 6 patients with bilaterally absent MEPs (16.7%) showed a good recovery. SEPs were significantly related to the outcome as well, but the combined use of SEP and MEP improved the outcome prediction, decreasing the rate of false negatives. Two patients had normal sensorimotor function, 13 a combined sensorimotor dysfunction, while 4 had a pure motor dysfunction. Our results suggest that SEPs and MEPs may improve the assessment of sensorimotor dysfunction in comatose patients. A significant relationship between MEPs and outcome appears to exist, but the assessment of MEP reliability requires further study.