Low- vs high-dose almitrine combined with nitric oxide to prevent hypoxia during open-chest one-lung ventilation.

BACKGROUND: Almitrine combined with inhaled nitric oxide (NO) can prevent hypoxia during one-lung ventilation (OLV). The optimal dose of almitrine that would provide therapeutic advantage with few side-effects during open-chest OLV has not been established. METHODS: Forty-two patients undergoing thoracotomy were randomly allocated to three groups: placebo, almitrine 4 microg kg(-1) min(-1) and inhaled NO 10 p.p.m. (ALM4+NO), and almitrine 16 microg kg(-1) min(-1) and inhaled NO 10 p.p.m. (ALM16+NO). Gas exchange, haemodynamic and respiratory variables and plasma concentrations of almitrine and lactate were monitored. Measurements were obtained with the patient awake (baseline), after induction of anaesthesia with two-lung ventilation (control 2LV), 20 min after treatment (2LV+T), and then at 10, 20 and 30 min of OLV (OLV10', OLV20' and OLV30') with FI(O2)1. RESULTS: In the placebo group, OLV impaired Pa(O2) and increased pulmonary shunt [16 (SD 7) kPa and 42 (10)% respectively]. These improved with ALM4+NO [26 (10) kPa and 31 (7)%; P<0.001]. ALM16+NO further improved PaO2) to 36 (13) kPa (P<0.0001) but gave no improvement in the shunt. Mean pulmonary artery pressure was similar in the placebo and ALM4+NO groups [20 (4) vs 23 (5) mm Hg], whereas it was increased in the ALM16+NO group to 28 (8) mm Hg (P<0.01). Plasma concentrations of almitrine and lactate were unaltered by the treatments. CONCLUSIONS: Low-dose almitrine (4 microg kg(-1) min(-1)) together with inhaled NO significantly improves oxygenation during open-chest OLV, without modifying pulmonary haemodynamics. An increased dose of almitrine (16 microg kg(-1) min(-1)) with inhaled NO further improves arterial oxygenation, but also increases mean pulmonary artery pressure.

[Cardiorespiratory arrest: a rare complication of subdural block]. / Parada cardiorrespiratoria: una complicación infrecuente del bloqueo subdural.

We report a case of accidental subdural block after epidural anesthesia that manifested as cardiac arrest due to extensive spinal blockade 20 minutes after administration of 50 mg of 0.5% bupivacaine. The event resolved without sequelae. Subdural placement of the catheter was verified by computed axial tomography contrast medium. Clinical signs of subdural block are highly variable, extensive neural block being among the possible rare presentations, with latency ranging from a few minutes to as long as 30. Recent electron microscope observations with new methods for fixing and preparing tissues suggest that the dubdural space does not exist naturally, but rather forms artificially within a low-resistance cell plane composed of neurothelial cells, as a result of trauma or the injection of a local anesthetic. The characteristics of the space depend, therefore, on factors that come together at the site. These data explain the great variability in the clinical manifestations of a subdural block. The case of cardiopulmonary arrest we report is rare in the literature.

Parada cardiorrespiratoria: una complicación infrecuente del bloqueo subdural / Cardiopulmonary arrest: a rare complication of subdural block

Presentamos un caso clínico subdural accidental tras anestesia epidural que se manifestó como paro cardíaco por bloqueo espinal extenso a los 20 minutos de la administración de 50 mg de bupivacaína al 0,5 por ciento que se resolvió sin secuelas; la localización subdural del catéter se confirmó mediante tomografía axial computarizada con la administración de una solución con contraste. La clínica del bloqueo subdural es muy variada, siendo una de sus posibles presentaciones infrecuentes, la de un bloqueo neural extenso de latencia variable entre pocos minutos a 30 minutos. Los recientes hallazgos obtenidos mediante microscopia electrónica con nuevos métodos de fijación y preparación de las muestras apuntan a que el espacio subdural no existe de forma natural, sino que se forma de modo artificial dentro de un plano celular de baja resistencia compuesto por células neuroteliales, como resultado de un trauma o de la inyección de anestésico local. Las características del espacio creado dependen, por tanto, de los factores que concurren en su origen. Estos datos permiten explicar la gran variabilidad en las presentaciones clínicas del bloqueo subdural.La clínica de paro cardiorrespiratorio del caso que presentamos es muy infrecuente (AU)

Consideraciones sobre la administración y monitorización de óxido nítrico inhalado / On the administration and monitoring of inhaled nitric oxide

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