Effect of fluid strategy on stroke volume, cardiac output, and fluid responsiveness in adult patients undergoing major abdominal surgery: a sub-study of the Restrictive versus Liberal Fluid Therapy in Major Abdominal Surgery (RELIEF) trial.

BACKGROUND: We designed a prospective sub-study of the larger Restrictive versus Liberal Fluid Therapy in Major Abdominal Surgery (RELIEF) trial to measure differences in stroke volume and other haemodynamic parameters at the end of the intraoperative fluid protocols. The haemodynamic effects of the two fluid regimens may increase our understanding of the observed perioperative outcomes. METHODS: Stroke volume and cardiac output were measured with both an oesophageal Doppler ultrasound monitor and arterial pressure waveform analysis. Stroke volume variation, pulse pressure variation, and plethysmographic variability index were also obtained. A passive leg raise manoeuvre was performed to identify fluid responsiveness. RESULTS: Analysis of 105 patients showed that the primary outcome, Doppler monitor-derived stroke volume index, was higher in the liberal group: restrictive 38.5 (28.6-48.8) vs liberal 44.0 (34.9-61.9) ml m-2; P=0.043. Similarly, there was a higher cardiac index in the liberal group: 2.96 (2.32-4.05) vs 2.42 (1.94-3.26) L min-1 m-2; P=0.015. Arterial-pressure-based stroke volume and cardiac index did not differ, nor was there a significant difference in stroke volume variation, pulse pressure variation, or plethysmographic variability index. The passive leg raise manoeuvre showed fluid responsiveness in 40% of restrictive and 30% of liberal protocol patients (not significant). CONCLUSIONS: The liberal fluid group from the RELIEF trial had significantly higher Doppler ultrasound monitor-derived stroke volume and cardiac output compared with the restrictive fluid group at the end of the intraoperative period. Measures of fluid responsiveness did not differ significantly between groups. CLINICAL TRIAL REGISTRATION: ACTRN12615000125527.

Aortic Acceleration Time and the Intraoperative Assessment of Aortic Stenosis.

OBJECTIVES: Aortic acceleration time (AAT) and the ratio of AAT to ejection time (AAT/ET) are relatively new echocardiographic measures of the severity of aortic stenosis (AS). This study investigated the utility of transesophageal echocardiography (TEE) measurements of AAT and AAT/ET to predict the severity of AS under intraoperative conditions. DESIGN: Retrospective diagnostic accuracy study. SETTING: St. Vincent's Hospital, Melbourne, Australia, from July 2007 to February 2017. PARTICIPANTS: The study comprised 199 patients who underwent aortic valve replacement (AVR) and whose aortic valves were evaluated with spectral Doppler analysis in both preoperative transthoracic echocardiography (TTE) and intraoperative TEE studies fewer than three months apart. Exclusion criteria included AVR for only aortic regurgitation, AVR of prosthetic aortic valves, and known left ventricular outflow tract obstruction. MEASUREMENTS AND MAIN RESULTS: Standard echocardiography assessment of AS and the AAT and AAT/ET measurements was performed using preoperative TTE and intraoperative TEE. The intraoperative AAT and AAT/ET were increased significantly in patients with both high- and low-gradient severe AS compared with patients without severe AS (p < 0.01). Comparing preoperative TTE and intraoperative TEE measurements showed that the AAT was significantly prolonged during general anesthesia (mean difference 9.67 msec [95% confidence interval -13.54 to -5.81]), whereas the AAT/ET was preserved (mean difference -0.0018 [95% confidence interval -0.013 to 0.0091]). An intraoperative TEE cutoff of 109 msec for AAT and 0.35 for AAT/ET had a 74% and 67% sensitivity and 72% and 78% specificity, respectively, to differentiate severe from non-severe AS. CONCLUSIONS: The AAT and AAT/ET may be useful adjuncts for the intraoperative measurement of AS. The agreement between intraoperative TEE and preoperative TTE was better with AAT/ET compared with AAT alone.

A pilot randomized-controlled trial evaluating the erector spinae plane block in thoracic and breast surgery.

PURPOSE: This pilot study evaluated the feasibility of investigating the effect of the erector spinae plane (ESP) block on the patient-centred outcomes of quality of recovery-15 (QoR-15), and brief pain inventory (BPI) in thoracic and breast surgery patients. METHODS: In this randomized-controlled pilot trial, 82 patients undergoing video-assisted thoracoscopic surgery (n = 77) and mastectomy (n = 5) received either continuous ESP block with ropivacaine (ropivacaine group) or the same procedure with 0.9% saline (saline group). All patients received surgical intercostal block (thoracic surgery) or local anesthetic infiltration (breast surgery). Feasibility as the primary outcome was evaluated on recruitment (three patients per week), catheter retention (above 90% at 24 hr), and patient attrition (less than 10%). Secondary outcomes comprised of QoR-15, BPI, and opioid consumption. RESULTS: Recruitment rate was 1.8 patients per week. Catheters were retained in 77 patients (94%) at 24 hr. At three months, five patients were lost to follow-up (6%). At 24 hr compared with baseline, the ropivacaine group had a smaller decline in QoR-15 score (median difference, 14; 95% confidence interval [CI], 2 to 26; P = 0.02) and a smaller increase in BPI global score (median difference, 14; 95% CI, 0 to 24; P = 0.048). There was no difference in opioid consumption (P = 0.08). CONCLUSIONS: In this pilot study, the target recruitment rate was not met, but catheter retention and patient attrition rates were both satisfactory. A definitive trial with QoR-15 as the primary outcome would require 300 study participants. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry (ID12618000701224); registered 30 April 2018.

RéSUMé: OBJECTIF: Cette étude pilote a évalué la faisabilité d'explorer l'effet d'un bloc du plan des muscles érecteurs du rachis sur des résultats centrés sur le patient, soit la qualité de récupération (QoR-15) et le Questionnaire concis de la douleur (QCD ou BPI 'Brief Pain Inventory'), chez les patients de chirurgie thoracique et mammaire. MéTHODE: Dans cette étude pilote randomisée contrôlée, 82 patients subissant une chirurgie thoracoscopique (n = 77) ou une mastectomie (n = 5) ont reçu soit un bloc continu du plan des muscles érecteurs du rachis avec de la ropivacaïne (groupe ropivacaïne), ou la même intervention avec une solution saline à 0,9 % (groupe salin). Tous les patients ont reçu un bloc intercostal chirurgical (chirurgie thoracique) ou une infiltration d'anesthésique local (chirurgie mammaire). La faisabilité a été évaluée par les critères de recrutement (trois patients par semaine), de la rétention du cathéter (plus de 90 % à 24 h), et du taux d'attrition des patients (moins de 10 %). Les critères d'évaluation secondaires comportaient la QoR-15, le QCD et la consommation d'opioïdes. RéSULTATS: Le taux de recrutement était de 1,8 patients par semaine. Les cathéters sont restés en place chez 77 patients (94 %) à 24 h. À trois mois, cinq patients ont été perdus au suivi (6 %). Après 24 h, par rapport aux valeurs de base, le groupe ropivacaïne présentait un déclin plus léger du score de QoR-15 (différence médiane, 14; intervalle de confiance [IC] 95 %, 2 à 26; P = 0,02) ainsi qu'une augmentation moindre du score global de QCD (différence médiane, 14; IC 95 %, 0 à 24; P = 0,048). Aucune différence n'a été observée en matière de consommation d'opioïdes (P = 0,08). CONCLUSION: Dans cette étude pilote, le taux de recrutement cible n'a pas été atteint, mais les taux de rétention des cathéters et d'attrition des patients étaient tous deux satisfaisants. Une étude définitive de la QoR-15 en tant que critère d'évaluation principal nécessiterait le recrutement de 300 participants. ENREGISTREMENT DE L'éTUDE: Australian New Zealand Clinical Trials Registry (ID12618000701224); enregistrée le 30 avril 2018.

Did ultrasound fulfill the promise of safety in regional anesthesia?

PURPOSE OF REVIEW: Ultrasound guidance has become the accepted standard of practice for peripheral regional anesthesia. Despite evidence supporting the efficacy of ultrasound-guided regional anesthesia, its impact on patient safety has been less clear. RECENT FINDINGS: Evidence has been consistent that ultrasound guidance reduces the incidence of vascular injury, local anesthetic systemic toxicity, pneumothorax and phrenic nerve block. Within the limited global scope of the epidemiology and etiologic complexity of perioperative (including block-related) peripheral nerve injury, there has not been consistent evidence that ultrasound guidance is associated with a reduced incidence of nerve injury. However, a recently published retrospective cohort study has demonstrated that the incidence of short-term nerve injury was decreased with ultrasound guidance compared with nerve stimulation. Ultrasound has led to development of novel blocks, approaches and refinement of existing ones, which may contribute to patient safety. SUMMARY: Ultrasound has revolutionized the way we approach regional anesthesia and contributed to patient safety. It is important to note that patient safety does not hinge on one single technology. Patient safety in regional anesthesia relies on a well trained practitioner to pay meticulous attention to indication, block and patient selection, anatomy, pharmacology, equipment and technique.

Neuraxial and Combined Neuraxial/General Anesthesia Compared to General Anesthesia for Major Truncal and Lower Limb Surgery: A Systematic Review and Meta-analysis.

Neuraxial anesthesia may improve perioperative outcomes when compared to general anesthesia; however, this is controversial. We performed a systematic review and meta-analysis using randomized controlled trials and population-based observational studies identified in MEDLINE, PubMed, and EMBASE from 2010 to May 31, 2016. Studies were included for adult patients undergoing major surgery of the trunk and lower extremity that reported: 30-day mortality (primary outcome), cardiopulmonary morbidity, surgical site infection, thromboembolic events, blood transfusion, and resource use. Perioperative outcomes were compared with general anesthesia for the following subgroups: combined neuraxial-general anesthesia and neuraxial anesthesia alone. Odds ratios (ORs) and 99% confidence intervals (CIs) were calculated to identify the impact of anesthetic technique on outcomes. Twenty-seven observational studies and 11 randomized control trials were identified. This analysis comprises 1,082,965 records from observational studies or databases and 1134 patients from randomized controlled trials. There was no difference in 30-day mortality identified when combined neuraxial-general anesthesia was compared with general anesthesia (OR 0.88; 99% CI, 0.77-1.01), or when neuraxial anesthesia was compared with general anesthesia (OR 0.98; 99% CI, 0.92-1.04). When combined neuraxial-general anesthesia was compared with general anesthesia, combined neuraxial-general anesthesia was associated with a reduced odds of pulmonary complication (OR 0.84; 99% CI, 0.79-0.88), surgical site infection (OR 0.93; 99% CI, 0.88-0.98), blood transfusion (OR 0.90; 99% CI, 0.87-0.93), thromboembolic events (OR 0.84; 99% CI, 0.73-0.98), length of stay (mean difference -0.16 days; 99% CI, -0.17 to -0.15), and intensive care unit admission (OR 0.77; 99% CI, 0.73-0.81). For the combined neuraxial-general anesthesia subgroup, there were increased odds of myocardial infarction (OR 1.18; 99% CI, 1.01-1.37). There was no difference identified in the odds of pneumonia (OR 0.94; 99% CI, 0.87-1.02) or cardiac complications (OR 1.04; 99% CI, 1.00-1.09) for the combined neuraxial-general anesthesia subgroup. When neuraxial anesthesia was compared to general anesthesia, there was a decreased odds of any pulmonary complication (OR 0.38; 99% CI, 0.36-0.40), surgical site infection (OR 0.76; 99% CI, 0.71-0.82), blood transfusion (OR 0.85; 99% CI, 0.82-0.88), thromboembolic events (OR 0.79; 99% CI, 0.68-0.91), length of stay (mean difference -0.29 days; 99% CI, -0.29 to -0.28), and intensive care unit admission (OR 0.50; 99% CI, 0.48-0.53). There was no difference in the odds of cardiac complications (OR 0.99; 99% CI, 0.94-1.03), myocardial infarction (OR 0.91; 99% CI, 0.81-1.02), or pneumonia (OR 0.92; 99% CI, 0.84-1.01). Randomized control trials revealed no difference in requirement for blood transfusion (RR 1.05; 99% CI, 0.65-1.71) and a decreased length of stay (mean difference -0.15 days; 99% CI, -0.27 to -0.04). Neuraxial anesthesia when combined with general anesthesia or when used alone was not associated with decreased 30-day mortality. Neuraxial anesthesia may improve pulmonary outcomes and reduce resource use when compared with general anesthesia. However, because observational studies were included in this analysis, there is a risk of residual confounding and therefore these results should be interpreted with caution.

Wrong-site regional anesthesia: review and recommendations for prevention?

PURPOSE OF REVIEW: Wrong-site regional anesthetic procedures are considered never events. The purpose of this review is to describe the phenomenon of wrong-site regional anesthetic blocks and identify preventive strategies. RECENT FINDINGS: The incidence of wrong-site block may be as frequent as 7.5 per 10,000 procedures. Factors contributing to wrong-site block include physician distraction, patient position change, scheduling changes, inadequate documentation, poor communication, lack of surgical consent, site marking not visible, inadequate supervision, reduced situational awareness, fatigue, cognitive overload, perceived time pressure, delay from World Health sign-in to block performance and omission of block time-out or block time-out occurring before final patient positioning. The American Society of Regional Anesthesia and Pain Medicine have created a 9-point checklist for regional anesthesia procedures. SUMMARY: Preoperative site verification and surgical site marking are mandatory. A time-out should occur immediately before any invasive procedure. Confirming the correct patient and block site with a time-out should occur immediately before all regional anesthetic procedures. If more than one block is performed on one patient, it is recommended that time-out be repeated each time the patient position is changed or separated in time or performed by a different team. The anesthetic team should uniformly implement robust guidelines and checklists to reduce the occurrence of wrong-site regional anesthetic procedures.

Aortic Valve Thrombosis after Valve-Sparing Aortic Root Replacement and Insertion of an Extracorporeal Left Ventricular Assist Device, Masked by Mediastinal Packing.

Aortic valve (AV) or aortic root thrombus related to a left ventricular assist device (LVAD) is a relatively uncommon but potentially life-threatening complication. In the present report, we describe a complex case where echocardiographic diagnosis of AV thrombosis was obscured by the presence of mediastinal packing in a patient who underwent valve-sparing aortic root replacement and insertion of the CentriMag™ LVAD for postcardiotomy cardiogenic shock. A large AV thrombus may develop rapidly in patients with LVADs. This case highlights the importance of a careful and thorough transesophageal echocardiography examination in detecting this complication and in altering surgical management.