RESUMEN
Nitric oxide (NO) is an important mediator in ischemia-reperfusion injury during human orthotopic liver transplantation (OLT). The perioperative kinetics of nitrite/nitrate plasma levels in 25 patients undergoing uncomplicated OLT were studied. A uniform pattern with significant increases of nitrite/nitrate levels immediately after reperfusion was seen in all patients, followed by a decrease to pretransplant levels within 24h. Peak levels 30 min after reperfusion were correlated to the indocyanine green plasma disappearance rate (PDR(ICG)), suggesting an association of early released NO with graft perfusion in OLT.
Asunto(s)
Trasplante de Hígado , Nitratos/sangre , Nitritos/sangre , Adulto , Humanos , Cinética , Hepatopatías/sangre , Hepatopatías/cirugía , Persona de Mediana EdadRESUMEN
Intrathecal (IT) clonidine is an effective analgesic, but it also produces hemodynamic depression and sedation which are likely to be related to IT clonidine's cephalad spread within the cerebrospinal fluid. We hypothesized that IT clonidine's side effects could be reduced without compromising the duration and quality of analgesia by injecting clonidine IT in a hyperbaric solution and elevating the patient's trunk. We prospectively randomized 30 elderly patients to receive IT 150 microg of either isobaric (ISO) or hyperbaric (HYPER) clonidine for postoperative analgesia after surgical repair of traumatic hip fracture. Hemodynamics, IV fluid administration, visual analog pain scores, sedation scores, and clonidine cerebrospinal fluid levels were recorded at fixed intervals. Patients in the ISO group required significantly more crystalloid fluid administration (median, 2500 mL; range, 1500-3000 mL) than those in the HYPER group (median, 1500; range, 500-3000 mL) to maintain adequate arterial blood pressure (P < 0.01). Also, the decrease in heart rate was significantly more pronounced in the ISO than in the HYPER group (P < 0.01). The duration of analgesia was significantly larger in the ISO (median, 400 min; range, 115-400 min) than in the HYPER (median, 265 min; range, 205-400 min) group (P < 0.05). Sedation scores did not differ between groups. We conclude that increasing the baricity of IT clonidine solution in the conditions of our experiment reduces hemodynamic side effects but also analgesia from IT administered clonidine.
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Agonistas alfa-Adrenérgicos/uso terapéutico , Clonidina/uso terapéutico , Hemodinámica/fisiología , Dolor Postoperatorio/tratamiento farmacológico , Dolor Postoperatorio/fisiopatología , Agonistas alfa-Adrenérgicos/administración & dosificación , Agonistas alfa-Adrenérgicos/efectos adversos , Anciano , Presión Sanguínea/efectos de los fármacos , Presión Sanguínea/fisiología , Clonidina/administración & dosificación , Clonidina/efectos adversos , Método Doble Ciego , Femenino , Frecuencia Cardíaca/efectos de los fármacos , Frecuencia Cardíaca/fisiología , Hemodinámica/efectos de los fármacos , Fracturas de Cadera/cirugía , Humanos , Inyecciones Espinales , Masculino , Procedimientos Ortopédicos , Dimensión del Dolor/efectos de los fármacos , Presión , Estudios ProspectivosRESUMEN
BACKGROUND: Cerebrovascular carbon dioxide reactivity during high-dose remifentanil infusion was investigated in volunteers by measurement of regional cerebral blood flow (rCBF) and mean CBF velocity (CBFv). METHODS: Ten healthy male volunteers with a laryngeal mask for artificial ventilation received remifentanil at an infusion rate of 2 and 4 microg x kg-1 x min-1 under normocapnia, hypocapnia, and hypercapnia. Stable xenon-enhanced computed tomography and transcranial Doppler ultrasonography of the left middle cerebral artery were used to assess rCBF and mean CBFv, respectively. If required, blood pressure was maintained within baseline values with intravenous phenylephrine to avoid confounding effects of altered hemodynamics. RESULTS: Hemodynamic parameters were maintained constant over time. Remifentanil infusion at 2 and 4 microg x kg-1 x min-1 significantly decreased rCBF and mean CBFv. Both rCBF and mean CBFv increased as the arterial carbon dioxide tension increased from hypocapnia to hypercapnia, indicating that cerebrovascular reactivity remained intact. The average slopes of rCBF reactivity were 0.56 +/- 0.27 and 0.49 +/- 0.28 ml. 100 g-1 x min-1 x mmHg-1 for 2 and 4 microg x kg-1 x min-1 remifentanil, respectively (relative change in percent/mmHg: 1.9 +/- 0.8 and 1.6 +/- 0.5, respectively). The average slopes for mean CBFv reactivity were 1.61 +/- 0.95 and 1.54 +/- 0.83 cm x s-1 x mmHg-1 for 2 and 4 microg x kg-1 x min-1 remifentanil, respectively (relative change in percent/mmHg: 1.86 +/- 0.59 and 1.79 +/- 0.59, respectively). Preanesthesia and postanesthesia values of rCBF and mean CBFv did not differ. CONCLUSION: High-dose remifentanil decreases rCBF and mean CBFv without impairing cerebrovascular carbon dioxide reactivity. This, together with its known short duration of action, makes remifentanil a useful agent in the intensive care unit when sedation that can be titrated rapidly is required.
Asunto(s)
Dióxido de Carbono/metabolismo , Circulación Cerebrovascular/efectos de los fármacos , Piperidinas/administración & dosificación , Adulto , Circulación Cerebrovascular/fisiología , Relación Dosis-Respuesta a Droga , Humanos , Masculino , RemifentaniloRESUMEN
BACKGROUND: Postoperative nausea and vomiting (PONV) occurs frequently after gynecologic surgery. Because hemodynamic condition seems to be influential, women presenting with preoperative orthostatic dysregulation may have an increased risk for PONV. The aim of the present study was to assess the relationship between preoperative orthostatic dysregulation and the incidence of PONV. METHODS: In a prospective observer-blinded clinical trial, 200 women who were scheduled for elective gynecologic surgery underwent an orthostatic test on the day before surgery. Based on the orthostatic test results, women were stratified into orthostatic dysregulation (OR; systolic blood pressure decrease > 20 mmHg on standing up) and nonorthostatic dysregulation (NOR; systolic blood pressure decrease < 20 mmHg) groups. RESULTS: Forty-nine women were stratified to the OR group and 151 to the NOR group. Frequencies of PONV and vomiting during the study period were higher in the OR group compared with the NOR group (77.6% vs. 31.1% and 55.1 vs. 18.5%, respectively; all P < 0.001). Women with hypotension in their history showed a significantly higher frequency of PONV within 24 h (P < 0.05). CONCLUSION: Women presenting with orthostatic dysregulation and arterial hypotension in their history exhibit an increased risk of PONV.
Asunto(s)
Náusea y Vómito Posoperatorios/epidemiología , Postura , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Incidencia , Modelos Logísticos , Persona de Mediana Edad , Náusea y Vómito Posoperatorios/etiología , Estudios ProspectivosRESUMEN
UNLABELLED: In this clinical study, we tested the hypothesis that a marked systolic blood pressure decrease >35% (DeltaSBP >35%) from preanesthetic baseline during the induction and maintenance of anesthesia is associated with more postoperative nausea and vomiting (PONV). In 300 ASA physical status I and II women undergoing elective gynecological surgery with general anesthesia, the maximum DeltaSBP during the induction as well as maintenance of general anesthesia were calculated. Observers blinded to hemodynamic variables assessed the incidence of PONV. The overall incidence of nausea (visual analog scale >4) and vomiting within the immediate observation period (0-2 h) was 39% and 25%, respectively. Frequency of nausea and vomiting in the late observation period was 21% and 9%, respectively. Women with a DeltaSBP >35% during the induction of anesthesia suffered from a more frequent incidence of PONV within the immediate (57% versus 35% and 41% versus 22%, respectively; P < 0.01) and within the late observation period (33% versus 18% and 19% versus 7%, respectively; P < or = 0.01). In women with a DeltaSBP >35% during maintenance of anesthesia, a more frequent incidence of nausea within the immediate observation period (53% versus 36%; P < 0.05) was found. We conclude that a maximum DeltaSBP >35% during the anesthetic induction is associated with an increased incidence of PONV after gynecological surgery during general anesthesia. IMPLICATIONS: A prospective clinical investigation revealed that a marked systolic blood pressure decrease >35% (DeltaSBP >35%) during the induction of general anesthesia is associated with an increased incidence of postoperative nausea and vomiting (PONV). The association between a DeltaSBP >35% during maintenance of general anesthesia and PONV is less pronounced.