Intravenous dexmedetomidine for the treatment of shivering during Cesarean delivery under neuraxial anesthesia: a randomized-controlled trial.

PURPOSE: About 55% of patients undergoing a Cesarean delivery under spinal or epidural anesthesia will experience shivering, which may interfere with the monitoring of vital signs. Recent studies have shown that dexmedetomidine could potentially help to alleviate shivering associated with anesthesia. We investigated whether dexmedetomidine, an alpha 2-adrenergic agonist, reduces the duration of shivering associated with neuraxial anesthesia during Cesarean delivery. METHODS: Eighty parturients undergoing Cesarean delivery under neuraxial anesthesia and experiencing shivering were enlisted in this prospective, randomized, double-blind trial. After childbirth, the intervention group (n = 40) received a single intravenous bolus of dexmedetomidine (30 µg) while the control group (n = 40) received saline. Randomization and allocation were based on a computer-generated list. The primary outcome measure was the time required for an observable decrease in shivering after the intervention. RESULTS: One hundred fifty-five patients were recruited, 80 of whom presented with shivering and were randomized. Our study showed that dexmedetomidine reduced the mean (standard deviation) duration of shivering after a single intravenous bolus to 2.6 (2.1) min after dexmedetomidine from 17.9 (12.6) min after saline (difference in means, -15.3 min; 95% confidence interval [CI], -11.2 to -19.4). The effect of dexmedetomidine persisted 15 min after the bolus was administered, as shivering had completely stopped in 90% of the patients in the intervention group vs 22.5% in the control group (relative risk, 4.0; 95% CI, 2.2 to 7.2). No adverse effects, including bradycardia, were observed. CONCLUSION: A single intravenous bolus of dexmedetomidine decreased the duration of shivering for up to 15 min during Cesarean delivery under neuraxial anesthesia. TRIAL REGISTRATION: www.clinicaltrials.gov (NCT02384343); registered 10 March, 2015.

RéSUMé: OBJECTIF: Environ 55 % des patientes subissant un accouchement par césarienne sous anesthésie rachidienne ou épidurale vont manifester des frissons, lesquels peuvent interférer avec la mesure des signes vitaux. Des études récentes ont démontré que la dexmédétomidine a le potentiel de réduire les frissons associés à l'anesthésie. Nous avons cherché à démontrer si la dexmédétomidine, un agoniste des récepteurs alpha-2-adrénergiques, peut réduire la durée des frissons associés à l'anesthésie neuraxiale lors d'un accouchement par césarienne. MéTHODE: Quatre-vingts parturientes subissant un accouchement par césarienne sous anesthésie neuraxiale et manifestant des frissons ont été recrutées pour cette étude prospective, randomisée et à double insu. Après la naissance, le groupe intervention (n = 40) a reçu un bolus intraveineux unique de dexmédétomidine (30 µg) alors que le groupe témoin (n = 40) a reçu une solution saline. La randomisation et l'attribution ont suivi une liste générée par ordinateur. Le critère d'évaluation principal était le temps nécessaire avant d'observer une réduction des frissons après l'intervention. RéSULTATS: Cent cinquante-cinq patientes ont été recrutées, dont 80 ont présenté des frissons et ont été randomisées. Notre étude a montré que la dexmédétomidine réduisait la durée moyenne (écart type) des frissons après un bolus intraveineux unique à 2,6 (2,1) min après l'administration de dexmédétomidine par rapport à une durée moyenne de 17,9 (12,6) min après la solution saline (différence de moyennes, -15,3 min; intervalle de confiance [IC] 95 %, -11,2 à -19,4). L'effet de la dexmédétomidine persistait 15 min après l'administration du bolus, où les frissons avaient complètement cessé chez 90 % des patientes du groupe intervention vs 22,5 % du groupe témoin (risque relatif, 4,0; IC 95 %, 2,2 à 7,2). Aucun effet secondaire néfaste, y compris la bradycardie, n'a été observé. CONCLUSION: Un bolus intraveineux unique de dexmédétomidine réduit la durée des frissons jusqu'à 15 min lors d'un accouchement par césarienne sous anesthésie neuraxiale. ENREGISTREMENT DE L'éTUDE: www.clinicaltrials.gov (NCT02384343); enregistrée le 10 mars 2015.

The estimation of cardiac output by the Nexfin device is of poor reliability for tracking the effects of a fluid challenge.

INTRODUCTION: The Nexfin device estimates arterial pressure by the volume clamp method through a finger pneumatic cuff. It also allows to estimate cardiac index (CInoninv) by pulse contour analysis of the non-invasive arterial pressure curve. We evaluated the ability of the device to track changes in cardiac index induced by a fluid challenge. METHODS: We included 45 patients for whom a volume expansion (500 mL of saline infused over 30 min) was planned. The volume expansion-induced changes in cardiac index measured by transpulmonary thermodilution (CIinv, PiCCO device) and in CInoninv were recorded. RESULTS: In seven patients, the Nexfin could not record the arterial curve due to finger hypoperfusion. Considering both the values obtained before and after volume expansion (n = 76 pairs of measurements), the bias (lower and upper limits of agreement) between CIinv and CInoninv was 0.2 (-1.8 to 2.2) L/min/m2. The mean change in CInoninv was 10 ± 11%. The percentage error of CInoninv was 57%. The correlation between the changes in CIinv and CInoninv observed during volume expansion was significant (P = 0.0002) with an r2 = 0.31. CONCLUSIONS: The estimation of CI by the Nexfin device in critically ill patients is not reliable, neither for estimating absolute values of CI nor for tracking its changes during volume expansion.

Glioblastoma multiforme e infecção pelo HIV: associação coincidente ou possível influência oncogênica? / Glioblastoma multiforme and Acquired Immunodeficiency Syndrome: coincidental association or a possible oncogenic influence?

O glioblastoma multiforme é o tumor cerebral primário glial mais maligno em adultos e de altaincidência dentre os tipos de astrocitomas, mas geralmente não é incluído no diagnóstico diferencial das lesões do sistema nervoso central em pacientes com o vírus da imunodeficiência humana (HIV). Alguns estudos têm descrito a associação entre glioblastoma e HIV. Relato do caso: Trata-se de glioblastoma em um homem de 31 anos de idade com HIV. Outras possíveis lesões, como o linfoma, foram sugeridas como diagnóstico diferencial, mas a investigação histopatológica confirmou tratar-se de glioblastoma. Esse paciente, submetido à cirurgia, evoluiu bem, sem déficits neurológicos no pós-cirúrgico imediato, e exames clínicos e de neuroimagem não mostraram sinais de recorrência até três meses de pós--operatório. Terapia adjuvante com radiação externa foi recomendada para o paciente.

Glioblastoma multiforme is the most malignant primary brain glial tumour in adults with high incidence among astrocytomas, but usually it is not included in the differential diagnosis of the central nervous system lesions in patients with Human Immunodeficiency Virus (HIV). Some studies have described the association of glioblastoma and HIV. Case report: It is reported a case of glioblastomas in a 31 year old man with HIV. Mass lesions such as lymphoma were suggested as differential diagnosis, but the histopathology confirmed the diagnosis of glioblastoma. This patient was operated with good neurological evolution immediately after surgery; no clinical or neuroimaging signs of recurrence were observed up to 3 months post-operatively. Adjuvant external radiation therapy was commenced for the patient.