Lata Paranandi

Factors predisposing to clinical disability in patients with cavernous malformations of the brain.

The factors predisposing to an aggressive clinical course in cavernous malformations of the brain are not known. Disabilities from neurological deficits and from seizures were assessed and graded in 84 patients harboring 100 cavernous malformations and were correlated with patient sex and age, lesion size, lesion location, lesion multiplicity, and previous overt hemorrhage. Univariate analysis showed that female sex, infratentorial lesion location, and previous gross hemorrhage were significantly associated with subsequent neurological disability. Logistic regression analysis showed that infratentorial lesion location and previous gross hemorrhage were independent factors simultaneously and significantly associated with neurological disability. Age less than 40 was the only significant factor predisposing to seizure disability (in both univariate and multivariate analyses). Lesion size, multiplicity, and other factors did not influence clinical disability. This information should assist in management decisions regarding cavernous malformations.

Inotropic effects of angiotensin II on human cardiac muscle in vitro.

The direct effects of angiotensin II (Ang II) on human cardiac muscle were investigated using isolated trabecular muscles from failing and functionally normal hearts. Atrial and ventricular trabeculae were studied. Results demonstrated a positive inotropic effect of Ang II on human cardiac muscle. Comparison of the effects of Ang II among groups indicated that the responsiveness tended to be greater in atrial and normal muscle compared with failing muscle. Results of this study also demonstrated heterogeneity in the responsiveness to Ang II among human muscles, which was not correlated with patient age, sex, diagnosis, prior treatment with angiotensin converting enzyme inhibitor, or heart function. A significant correlation between response to Ang II and response to isoproterenol was demonstrated in failing ventricular trabeculae, which may suggest that defects in beta-adrenergic responsiveness in the failing human ventricle are accompanied by a loss of responsiveness to Ang II. Studies were extended to the Syrian cardiomyopathic hamster and its control. A dose-dependent inotropic response occurred in normal hamster ventricular muscle but was significantly diminished in cardiomyopathic muscle. Ang II did not shorten the timing of contraction, and pretreatment with adrenergic-blocking agents did not shift the dose-response curve, indicating that the response was not cyclic AMP mediated. This study demonstrates for the first time that Ang II can exert an inotropic effect directly on human cardiac muscle and confirms that there is a direct effect of Ang II on hamster cardiac muscle. The study further suggests, however, that the inotropic response to Ang II in cardiac muscle is heterogeneous and may be diminished by heart failure.

Transcranial Doppler assessment of cerebral perfusion reserve in patients with carotid occlusive disease and no evidence of cerebral infarction

Using transcranial Doppler ultrasound (TCD), we measured bilateral middle cerebral artery mean blood flow velocities (MCAVs) before and 10 minutes after intravenous infusion of 1 gram of acetazolamide in 20 patients without cerebral infarction. Seven patients had normal carotid arteries (group 1), seven had unilateral internal carotid artery (ICA) stenosis ≥75% (group 2), and six had unilateral ICA occlusion (group 3). Before acetazolamide infusion, side-to-side differences in MCAV were 0.06 cm/sec in group 1 (p = 0.98), 4.3 cm/sec in group 2 (p = 0.36), and 15.0 cm/sec in group 3 (p = 0.02). Bilateral MCAV increased in all three groups after acetazolamide infusion, and the side-to-side differences in MCAV were 3.2 cm/sec in group 1 (p = 0.40), 11.4 cm/sec in group 2 (p = 0.04), and 27.6 cm/sec in group 3 (p = 0.03). Patients with carotid stenosis or occlusion and ipsilateral transient ischemic attacks (TIAs) had higher side-to-side differences in MCAV before (p = 0.03) and after (p = 0.01) acetazolamide than did asymptomatic patients with carotid disease. The association of impaired cerebral perfusion reserve and TIAs suggests that the TCD-acetazolamide test may enable identification of a subgroup of patients with carotid occlusive disease who are at higher risk for stroke.

Use of an appetite and diet assessment tool in the pilot phase of a hemodialysis clinical trial: Mortality and morbidity in hemodialysis study☆

Abstract An appetite and diet assessment tool (ADAT) was developed for the National Institutes of Health pilot study, Reduction of Morbidity and Mortality in Hemodialysis Patients, to evaluate appetite and factors affecting dietary intake in hemodialysis patients in relation to the dose of dialysis delivered and/or the flux of the dialysis membrane. Forty-seven patients completed the ADAT during baseline (28 men, mean age of 63 years; 19 women, mean age of 61 years), and 31 patients in follow-up (18 men, mean age of 63 years; 13 women, mean age of 60 years). Dietary protein and energy intakes were determined in baseline using diet diary-assisted recalls. The data presented suggest that the ADAT is a practical tool for assessing the relationship between appetite and dietary intake in hemodialysis patients. It may be used in dialysis facilities to evaluate appetite and dietary habits, and to assess the effects of changes in the patients medical condition that may impact appetite and nutritional status. The effect of delivered dose of dialysis and membrane flux will be assessed during the current full-scale study for possible effects on level of appetite and its correlation with nutritional status, morbidity, and mortality. The full-scale hemodialysis study will provide an opportunity to test the validity and reliability of the ADAT, and its applicability in future clinical trials.

Reoperations and visual results after failed pneumatic retinopexy

A single pneumatic retinopexy (PR) procedure failed to achieve permanent retinal reattachment in 23 (23%) of 101 cases of simple primary retinal detachment (RD). In 12 (16%) of 76 cases that were phakic or had an intact posterior capsule, a single PR failed compared with 11 (44%) of 25 cases without an intact posterior capsule. A total of 27 reoperations including eight repeat PRs (5 of which were successful) was required to achieve permanent retinal reattachment. Comparison of the final visual acuity and change from preoperative to final visual acuity between the initially failed and the successful cases demonstrated that initial failure of PR does not adversely affect the visual outcome. In all cases, the retina remained reattached at latest follow-up.

Systemic lidocaine and human somatosensoryevoked potentials during sufentanil-isoflurane anaesthesia

The effect of systemically administered lidocaine on somatosensory evoked potentials (SSEPs) during general anaesthesia has not been widely reported. Knowledge of the influence of anaesthetic agents on evoked potentials assists in interpreting evoked potential waveforms. Accordingly, we studied the behaviour of cortical and subcortical (recorded at the second cervical vertebra) SSEPs after administration of intravenous lidocaine (3 mg · kg−1 bolus followed by infusion at 4 mg · kg−1 · hr−1) during a sufentanil-based anaesthetic regimen in 16 patients undergoing abdominal or orthopaedic surgery. When compared to awake baseline recordings, the sufentanil-nitrous oxide, low-dose isoflurane anaesthetic depressed N1 amplitude by approximately 40% and prolonged latency by 10%. Fifteen minutes after establishment of this anaesthetic, the amplitude and latency of N1 were 1.13 ± 0.56 μV and 19.81 ± 1.63 msec, respectively. Within five minutes of adding lidocaine, amplitude decreased further to 0.84 ± 0.39 μV (P = 0.001), while latency was extended to 20.44 ± 1.48 msec (P = 0.01). Lidocaine did not affect cervical amplitude and prolonged latency only minimally. Despite the observed effects on amplitude and latency, SSEP waveforms were preserved and interpretable. Plasma lidocaine levels obtained at 5, 20, and 40 minutes after lidocaine were 5.17 ± 1.33, 3.76 ± 1.14, and 3.66 ± 0.9 μg · dl−1, respectively. Our results indicate that systemically administered lidocaine at therapeutic plasma levels acts synergistically with a sufentanilbased anaesthetic to depress the amplitude and prolong the latency of SSEPs.RésuméIl existe peu de publications sur l’effet de la lidocaine administrée par voie systemique sur les potentiels évoqués somatosensitifs (SSEP) pendant l’anesthésie générate. La connaissance des effets des agents anesthésiques sur les potentiels évoqués aide à l’interprétation des ondes de potentiels évoqués. Nous avons étudié l’effet de bl’administration de lidocaine par voie intraveineuse (bolus de 3 mg · kg−1 suivi d’une perfusion de 4 mg · kg−1 · h−1) sur les SSEP corticaux et sous-corticaux (enregistre au niveau de la deuxieme vertebre cervical) chez 16 patients anesthésiés avec une technique à base de sufentanil pendant une chirurgie abdominale ou orthopédique. Comparativement aux enregistrements de base en etat d’éveil, l’anesthésie à l’aide de sufentanil-protoxyde d’azote et faible dose d’isoflurane déprimait l’amplitude N1 d’environ 40% et prolongeait la latence de 10%. Après 15 minutes d’anesthésie, l’amplitude et la latence de Nl étaient de 1,13 ± 0,56 μV et 19,81 ± 1,63 msec respectivement. Cinq minutes après l’addition de lidocaine, l’amplitude a diminue a 0,84 ± 0,39 μV (P < 0,001) tandis que la latence a augmente a 20,44 ± 1,48 msec (P < 0,01). La lidocaine n ’a pas affecté l’amplitude cervical et a très peu prolonge la latence. Malgré les effets observés sur l’amplitude et la latence, les ondes SSEP étaient préservées et interprétables. Les niveaux plasmatiques de lidocaïne à 5, 20 et 40 minutes après l’injection étaient de 5,17 ± 1,33, 3,76 ± 1,14 et 3,66 ± 0,9 μg · dr−1 respectivement. Nos résultats démontrent que la lidocaine administree par voie systémique à des niveaux plasmatiques thérapeutiques agit en synergie avec une technique anesthésique à base de sufentanil en provoquant une dépression de l’amplitude et une prolongation de la latence des SSEP.

Intrathecal morphine for analgesia in children undergoing selective dorsal rhizotomy.

Selective dorsal root rhizotomy is performed for relief of spasticity in children with cerebral palsy. Postoperative pain relief can be provided by intrathecal morphine administered at the time of the procedure. We sought to define an optimal dose of intrathecal morphine in children undergoing selective rhizotomy, through a randomized, double-blinded prospective trial. After institutional approval and parental written informed consent, 27 patients, ages 3-10 years, were randomized to receive 10, 20, or 30 micrograms.kg-1 (Groups A, B, and C, respectively) of preservative-free morphine administered intrathecally by the surgeon after dural closure. Postoperatively, vital signs, pulse oximetry, and pain intensity scores were recorded hourly for 24 hr. Supplemental intravenous morphine was administered postoperatively according to a predetermined schedule based on pain scores. There was considerable individual variability in the time to initial morphine dosing and cumulative supplemental morphine dose. Time to first supplemental morphine dose was not different between groups. When compared to Groups A and B, cumulative 6-hr supplemental morphine dose was significantly lower in Group C (38.6 +/- 47 micrograms versus 79.1 +/- 74 and 189.6 +/- 126 for Groups A and B, respectively). By 12 hr, cumulative supplemental morphine dose was similar in Groups A and C. Group B consistently had a higher supplemental dose requirement than Groups A and C at 6, 12, and 18 hr. By 24 hr, there was no difference in cumulative dose among groups. Postoperative pain scores and the incidence of respiratory events, nausea, vomiting and pruritus were comparable among groups. These data suggest that intrathecal morphine at 30 micrograms.kg-1 provides the most intense analgesia at 6 hr following selective dorsal root rhizotomy, but was otherwise comparable to the 10 micrograms.kg-1 dose.

Evaluation of coexistent carotid and coronary disease by combined angiography.

We studied 247 patients who underwent combined coronary and carotid angiography to determine (a) the frequency of angiographic carotid stenosis (> 50%) in patients with coronary artery disease (CAD) and (b) the technical quality and safety of the combined procedure. All patients were evaluated primarily for CAD. Combined carotid angiography was performed for asymptomatic carotid bruits (115 patients, 47%), transient ischemic attacks (TIA) or stroke (66 patients, 26.5%), or inapparent/other reasons (66 patients, 26.5%). The extracranial internal carotid arteries were well visualized in 219 patients (89%); poor visualization of the internal carotid arteries was due to overlap by the vertebral or external carotid arteries. The frequency of >50% internal carotid stenosis was 36% in patients with asymptomatic carotid bruits, 42% in patients with TIA or stroke, and 8% in patients without TIA, stroke, or carotid bruits. Complication rates during combined coronary and carotid angiography in the 247 study patients were not statistically different from complication rates during coronary angiography alone in 686 control patients. These data indicate that (a) patients with CAD who have asymptomatic carotid bruits or a history of TIA or stroke have a high frequency of carotid stenosis, and (b) combined coronary and carotid angiography is a safe and technically adequate procedure.