ABSTRACT
OBJECTIVE: To demonstrate the efficacy of a digital nerve block for improving pulse oximetry in conditions of low tissue perfusion. METHOD: A randomized single-blind study of adult patients undergoing surgery under general anesthesia for conditions characterized by hypoperfusion. Patients were assigned to a control group or an experimental group. The experimental group received a digital nerve block in the middle finger of the left hand; a sensor was then placed on the finger for between 120 and 300 minutes. Age, sex, diagnosis, total observation time (TOT), percentage of time with no pulse oximeter signal (NoPO), and percentage of time with an unstable pulse oximeter signal (UnstPO) were recorded. Each patient was questioned between 16 and 24 hours after surgery and was examined for flushing, paresthesia, hypoesthesia, pain, and ecchymosis. The chi2 test was used to compare dichotomized or nominal variables and the t test was used to compare age, TOT, NoPO, and UnstPO. Values of P<.05 were considered statistically significant in both cases. RESULTS: Fifty patients were randomized to each group. A total of 82 patients remained in the study (control group=42, experimental group=40). There were no significant between-group differences in diagnoses or TOT. The mean values for NoPO and UnstPO were higher in the control group than in the experimental group (11.1% vs 4.4% and 35.9% vs 15.7%, respectively; P<.001). CONCLUSION: A digital nerve block can be used to prevent pulse oximetry failures in conditions of low peripheral perfusion.
Subject(s)
Autonomic Nerve Block , Fingers/blood supply , Ischemia/blood , Oximetry/methods , Oxygen/blood , Adult , Aged , Equipment Failure , Female , Fingers/innervation , Hemorrhage/blood , Humans , Male , Middle Aged , Peritonitis/blood , Shock/blood , Single-Blind Method , VasoconstrictionABSTRACT
OBJETIVO: Demostrar la eficacia del bloqueo de losnervios digitales (BND) para mejorar la oximetría depulso (OP) en condiciones de baja perfusión hística.MÉTODO: Pacientes adultos operados por afeccionescaracterizadas por hipoperfusión, conducidos con anestesiageneral, de forma aleatoria y con registros a simpleciego. Se asignaron a dos grupos: Grupo C (control) ygrupo B (experimental). El grupo B recibió un BND enel dedo medio de la mano izquierda donde se colocó elsensor con límites de tiempo entre 120 y 300 minutos. Seregistraron: edad, sexo, diagnóstico, tiempo total deobservación (TTO), porcentajes de tiempo con OP nodisponible (OPnodisp) y porcentaje de tiempo con OPinestable (OPinest). Entre 16 y 24 horas después de terminadala intervención se interrogó y examinó a cadapaciente en busca de rubor, parestesias, hipostesia,dolor y equimosis. Para las variables dicotómicas onominales se empleó la prueba χ2 y para comparar lasmedias de edad, TTO, OPnodisp, y OPinest, la prueba tde Student. En ambos casos con un nivel de significaciónde 0,05.RESULTADOS: Se asignaron 50 pacientes a cada grupo.Un total de 82 enfermos permanecieron en el ensayo(C=42 y B=40). No hubo diferencias significativas encuanto a diagnósticos ni TTO. En el grupo C los porcentajesde tiempo promedio con OPnodisp y OPinest fueronsuperiores (11,1% vs. 4,4% y 35,9% vs. 15,7%; respectivamente),p<0,001.CONCLUSIÓN: El BND es una alternativa para evitarlas fallas de OP en condiciones de baja perfusión periférica (AU)
OBJECTIVE: To demonstrate the efficacy of a digitalnerve block for improving pulse oximetry in conditionsof low tissue perfusion.METHOD: A randomized single-blind study of adultpatients undergoing surgery under general anesthesiafor conditions characterized by hypoperfusion. Patientswere assigned to a control group or an experimentalgroup. The experimental group received a digital nerveblock in the middle finger of the left hand; a sensor wasthen placed on the finger for between 120 and 300minutes. Age, sex, diagnosis, total observation time(TOT), percentage of time with no pulse oximeter signal(NoPO), and percentage of time with an unstable pulseoximeter signal (UnstPO) were recorded. Each patientwas questioned between 16 and 24 hours after surgeryand was examined for flushing, paresthesia,hypoesthesia, pain, and ecchymosis. The χ2 test was usedto compare dichotomized or nominal variables and the ttest was used to compare age, TOT, NoPO, and UnstPO.Values of P<.05 were considered statistically significantin both cases.RESULTS: Fifty patients were randomized to eachgroup. A total of 82 patients remained in the study(control group=42, experimental group=40). Therewere no significant between-group differences indiagnoses or TOT. The mean values for NoPO andUnstPO were higher in the control group than in theexperimental group (11.1% vs 4.4% and 35.9% vs15.7%, respectively; P<.001).CONCLUSION: A digital nerve block can be used toprevent pulse oximetry failures in conditions of lowperipheral perfusion (AU)
