Diaphragmatic paralysis, respiratory function, and postoperative pain after interscalene brachial plexus block with a reduced dose of 10 ml levobupivacaine 0.25% versus a 20 ml dose in patients undergoing arthroscopic shoulder surgery: study protocol for the randomized controlled double-blind REDOLEV study.

BACKGROUND: Arthroscopic shoulder surgery causes severe postoperative pain. An interscalene brachial plexus block provides adequate analgesia, but unintended spread of the local anesthetic administered may result in a phrenic nerve block, usually associated with a nonnegligible incidence of acute hemidiaphragmatic paralysis. The main purpose of this trial will be to analyze the incidence of hemidiaphragmatic paralysis ensuing after interscalene brachial plexus block in patients undergoing arthroscopic shoulder surgery administered a standard volume (20 ml) vs. a low volume (10 ml) of levobupivacaine 0.25%. METHODS: This will be a prospective double-blind randomized controlled single-center two-arm comparative trial. Forty-eight patients will be included. The primary goal will be to ultrasonographically determine the incidence of hemidiaphragmatic paralysis by calculating the diaphragmatic thickness ratio in each group. The secondary goals will be to compare the two arms in terms of (1) decrease in forced vital capacity and (2) in forced expiratory volume at 1 s by spirometry; (3) decrease in diaphragmatic excursion by ultrasound; (4) 24-h total intravenous morphine consumption; (5) time to first opioid request of a patient-controlled analgesia pump; and (6) postoperative complications. DISCUSSION: This trial will demonstrate that a low-volume interscalene brachial plexus block decreases hemidiaphragmatic paralysis following arthroscopic shoulder surgery according to spirometry and ultrasound measurements and does not provide inferior postoperative analgesia to the standard volume, as measured by opioid requirements. TRIAL REGISTRATION: EudraCT and Spanish Trial Register (REec) registration number: 2019-003855-12 (registered on 7 January 2020). ClinicalTrials.gov identification number: NCT04385966 (retrospectively registered on 8 May 2020). Ethics Committee approval: EC19/093 (18 December 2019).

Utilidad clínica y monitorización del consumo metabólico de oxígeno en anestesia / No disponible

La calorimetría indirecta puede ser un indicador de la evolución homeostática durante la cirugía. El estrés incrementa el consumo de oxígeno (VO2) y durante la anestesia se produce un descenso del VO2 derivado de la ausencia de energía cinética. Esto es un reflejo del metabolismo celular ante el trauma quirúrgico y la anestesia. Se necesitan más estudios para conocer cuál de los sistemas de medición de VO2 sea el más idóneo en anestesia, y cuáles pueden ser los valores límites de VO2 a partir de los que el anestesiólogo deba plantearse la actuación inmediata o evitar llegar a ellos (AU)

Indirect calorimetry could be an indicator of homeostatic changes during surgery. Stress increases oxygen consumption (VO2) and during anesthesia there is a decrease of VO2 arises from the absence of kinetic energy. The answer is cellular metabolism to the surgical trauma and anesthesia. More studies are necessary to know which of the VO2 measurement systems is the most appropriate in anesthesia, and what may be the limiting values of VO2 from which the anesthesiologist must consider immediate action or avoid making them (AU)

Recuperación y reinfusión de hematíes durante el postoperatorio / No disponible

El desarrollo de técnicas quirúrgicas cada vez más complejas, principalmente en cirugía cardiovascular y ortopédica, cirugía oncológica, trasplantes y pacientes politraumatizados han intensificado el aumento de las demandas de transfusiones. En los últimos años, se ha hecho necesario limitar al máximo la transfusión de sangre homóloga por los posibles efectos adversos de tipo inmunológico, e infeccioso por virus y priones. Recientemente, se han desarrollado nuevas medidas terapéuticas con el fin de reducir al mínimo la utilización de sangre homóloga, principalmente en cirugía programada, entre las que destacan las diferentes modalidades de autotransfusión postoperatoria (AU)

The development of surgical techniques increases complexity, particularly in cardiovascular and orthopedic surgery, cancer surgery, transplants and patients with multiple injuries has intensified the growing demands of transfusions. In recent years it has become necessary to minimize homologous blood transfusion by the possible adverse effects of immunological, and infection by viruses and prions. Recently, we have developed new therapeutic measures to minimize the use of homologous blood, mainly in elective surgery, among which the different modalities of postoperative autotransfusion (AU)

[Transcranial Doppler ultrasound, bispectral index, and electroencephalographic monitoring of entropy during sevoflurane anesthesia in children]. / Doppler transcraneal, BIS y entropía como medición indirecta del flujo cerebral durante la anestesia inhalatoria en pacientes pediátricos.

BACKGROUND AND OBJECTIVE: Transcranial Doppler ultrasound is a noninvasive technique for monitoring the velocity of blood flow in the main intracranial arteries, particularly those in the circle of Willis. Our aim was to assess whether changes in cerebral arterial blood flow in pediatric patients under sevoflurane anesthesia demonstrated by pulsed Doppler ultrasound correlate with changes in the bispectral (BIS) index and electroencephalographic state and response entropy (ES and ER, respectively). MATERIAL AND METHODS: Prospective, blinded observational study of 36 pediatric patients (age range, 5 to 11 years; ASA physical status classification, 1-2) under sevoflurane anesthesia for minor surgical procedures. Anesthesia was induced with sevoflurane and maintained with 2.5% sevoflurane in an inspired oxygen fraction of 50% in air. A continuous perfusion of remifentanil was provided for analgesia. In all patients we monitored hemodynamic and respiratory patterns, gases, temperature, and hypnosis (BIS, ES and ER) as well as cerebral blood flow estimated by pulsed Doppler ultrasound in the middle cerebral artery. The resistance index, pulsatility index, mean velocity, and estimated baseline cerebral blood flow were calculated from the Doppler sonogram. Correlations (Pearson's r) were calculated between BIS, ES, ER, the pulsatility index, resistance index, mean flow velocity, estimated cerebral blood flow, fraction of end-tidal carbon dioxide, and temperature. A regression model was constructed. RESULTS: Induction caused a pattern of high velocity (elevated mean velocity and normal or reduced pulsatility index) until the lowest BIS and ES values of 31 and 29, respectively, were reached. During maintenance, the Doppler sonogram pattern was slower (normalization of the pulsatility index, the resistance index, and mean velocity). Changes in flow and absolute entropy and BIS values were statistically correlated (Pearson's r values > or = 0.91); there was 95.6% agreement between Doppler values and BIS and agreement between BIS and ES values of 35 to 45. On awakening, flow velocities approached baseline values when BIS and ES rose to between 90 and 98. The estimated cerebral blood flow underwent fluctuations coinciding with an approximately concomitant increase or decrease in BIS (r > 0.95); the BIS response occurred with a slight delay of no more than a minute. The entropy measurements did not reflect the fluctuations. CONCLUSIONS: We show Doppler ultrasound patterns during anesthetic induction with sevoflurane. Systems for monitoring hypnosis could be considered indirect measurements of cerebral blood flow; BIS measurements are more sensitive to change. Transcranial Doppler ultrasound facilitates the observation of changes in blood flow that occur at different levels of hypnosis during anesthesia.