Background. We propose a 1-1-12 wash-in scheme for desflurane-nitrous oxide (N2O) low-flow anesthesia. The objective of our study was to determine the time to achieve alveolar concentration of desflurane (FAD) at 1, 2, 3, 4, 5, and 6%. Methods. We enrolled 106 patients scheduled for elective surgery under general anesthesia. After induction and intubation, wash-in was started with a fresh gas flow (FGF) of N2O : O2 1 : 1 L min−1 and vaporizer concentration of desflurane (FD) of 12%. Ventilation was controlled to maintain PACO2 at 30–35 mmHg. Results. The FAD rose rapidly from 0 to 4% in 2 min in a linear manner in 0.5 min increments. An FAD of 6% was achieved in 4 min in a linear fashion from FAD of 4% but in 1 min increments. An FAD of 1 to 6% occurred at 0.6, 1, 1.5, 2, 3, and 4 min. Heart rate during wash-in showed a statistically, albeit not clinically, significant pattern of increase. By contrast, blood pressure slightly decreased during this period. Conclusions. We developed a 1-1-12 wash-in scheme using a FGF of N2O : O2 1 : 1 L min−1 and FD of 12% for desflurane-nitrous oxide low-flow anesthesia. A respective FAD of 1, 2, 3, 4, 5, and 6% can be expected at 0.6, 1, 1.5, 2, 3, and 4 min.

BackgroundWe reported a 1-1-12 wash-in scheme for desflurane-nitrous oxide (N2O) low flow anesthesia that is simple, rapid, and predictable. There remain some situations where N2O should be avoided, which limits the generalizability of this wash-in scheme. The objective of our study was to determine the performance of this scheme in contexts where N2O is not used.MethodsWe recruited 106 patients scheduled for elective surgery under general anesthesia. After induction and intubation, wash-in was started with a fresh gas flow of air:O2 1:1 L/min and a vaporizer concentration of desflurane of 12%. Controlled ventilation was then adjusted to maintain PACO2 at 30–35 mmHg.ResultsThe alveolar concentration of desflurane (FAD) rose rapidly from 0% to 6% in 4 minutes in the same pattern as observed in our previous study in which N2O was used. An FAD of 7% was achieved in 6 minutes. An FAD of 1% to 7% occurred at 0.6, 1, 1.5, 2, 3, 4, and 6 minutes. The rise in heart rate during wash-in was statistically significant, although not clinically so. There was a slight but statistically significant decrease in blood pressure, but this had no clinical significance.ConclusionPerformance of the 1-1-12 wash-in scheme is independent of the use of N2O. Respective FADs of 1%, 2%, 3%, 4%, 5%, 6%, and 7% can be expected at 0.6, 1, 1.5, 2, 3, 4, and 6 minutes.

PurposeTo assess the efficacy of a transdermal fentanyl patch (TFP) (50 μg/hour) applied 10–12 hours before surgery versus placebo for postoperative pain control of total knee arthroplasty (TKA).Materials and methodsWe enrolled 40 patients undergoing elective TKA under spinal anesthesia using isobaric or hyperbaric bupivacaine. Subjects were randomized to receive a TFP (Duragesic® 50 μg/hour) or placebo patch applied with a self-adhesive to the anterior chest wall 10–12 hours before spinal anesthesia. Every patient was given patient-controlled morphine for postoperative pain control. Patients were evaluated every 4 hours until 48 hours.ResultsMorphine consumption at 24 and 48 hours in the TFP group versus the placebo group was 15.40±12.65 and 24.90±20.11 mg versus 33.60±19.06 and 57.80±12.65 mg (P≤0.001). Numeric rating scale scores at rest and during movement over 48 hours were lower in the TFP group. Ambulation and nausea/vomiting scores were statistically greater, but not clinically significant in the TFP group. Sedation scores were low and not statistically significantly different between groups. There was no severe respiratory depression.ConclusionTFP (50 μg/hour) applied 10–12 hours before surgery can effectively and safely decrease morphine consumption and pain scores during the first 48 hours after TKA surgery.

Background. Based on a pilot study with 34 patients, applying the modified sequential organ failure assessment (SOFA) score intraoperatively could predict a prolonged ICU stay, albeit with only 4 risk factors. Our objective was to develop a practicable intraoperative model for predicting prolonged ICU stay which included more relevant risk factors. Methods. An extensive literature review identified 6 other intraoperative risk factors affecting prolonged ICU stay. Another 168 patients were then recruited for whom all 10 risk factors were extracted and analyzed by logistic regression to form the new prognostic model. Results. The multivariate logistic regression analysis retained only 6 significant risk factors in the model: age ≥ 60 years, PaO2/FiO2 ratio ≤ 200 mmHg, platelet count ≤ 120,000/mm3, requirement for inotrope/vasopressor ≥ 2 drugs, serum potassium ≤ 3.2 mEq/L, and atrial fibrillation grading ≥2. This model was then simplified into the Open-Heart Intraoperative Risk (OHIR) score, comprising the same 6 risk factors for a total score of 7—a score of ≥3 indicating a likely prolonged ICU stay (AUC for ROC of 0.746). Conclusions. We developed a new, easy to calculate OHIR scoring system for predicting prolonged ICU stay as early as 3 hours after CPB. It comprises 6 risk factors, 5 of which can be manipulated intraoperatively.

Purpose Early goal-directed therapy (EGDT) using the FloTrac system reportedly improved postoperative outcomes among high-risk patients undergoing non-cardiac surgery. This study’s objective was to evaluate the FloTrac/EV1000 platform’s efficacy for improving postoperative outcomes in cardiac surgery. Patients and Methods Eighty-six adults undergoing coronary artery bypass graft (CABG) with cardiopulmonary bypass (CPB) in 2 tertiary referral centers were randomized to the EGDT or Control group. The Control group was managed with standard care to achieve the following goals: mean arterial pressure 65–90 mmHg; central venous pressure 8–12 mmHg; urine output ≥0.5 mL·kg −1 ·h −1 ; oxygen saturation >95%; and hematocrit 26–30%. The EGDT group was managed to reach similar goals using information from the FloTrac/EV1000 monitor. The targets were stroke volume variation <13%; stroke volume index 33–65 mL·beat −1 ·m −2 ; cardiac index 2.2–4.0 L·min −1 ·m −2 ; and systemic vascular resistance index 1600–2500 dynes·s·cm -5 ·m -2 . Results The intensive care unit (ICU) stay of the EGDT group was significantly shorter (mean difference −29.5 h; 95% CI −17.2 to −41.8, P < 0.001). The mechanical ventilation time was also shorter in the EGDT group (mean difference −11.3 h; 95% CI −2.7 to −19.9, P = 0.011). The hospital LOS was shorter in the EGDT group (mean difference −1.1 d; 95% CI −0.1 to −2.1, P = 0.038). Conclusion EGDT using FloTrac/EV1000 can be applied in CABG with CPB to improve postoperative outcomes.

Background The Analgesia Nociception Index (ANI) has been suggested as a non-invasive guide for analgesia. Our objective was to compare the efficacy of ANI vs. standard pharmacokinetic pattern for guiding intraoperative fentanyl administration. Methods This was a prospective, randomized, controlled study of adult female patients undergoing elective mastectomy under general anesthesia. The patients were randomized to the ANI-guided group receiving a loading dose of 75 μg of fentanyl followed by 25 μg when the ANI score was under 50. The Control group received the same loading dose followed by 25 μg every 30 min with additional doses when there were signs of inadequate analgesia (viz., tachycardia or hypertension). Results Sixty patients—30 in each group—were recruited. Although the actual mean ANI score was higher in the ANI-guided than in the Control group (mean difference 2.2; 95% CI: 0.3 to 4.0, P = 0.022), there was no difference in the primary outcome—i.e., intraoperative fentanyl consumption (mean difference − 4.2 μg; 95% CI: − 24.7 to 16.4, P = 0.686 and − 0.14 μg·kg− 1·h− 1; 95% CI: − 0.31 to 0.03, P = 0.105). No difference between groups was shown for either intraoperative blood pressure and heart rate, or for postoperative outcomes (i.e., pain scores, morphine consumption, or sedation scores) in the postanesthesia care unit. Conclusions Intraoperative fentanyl administration guided by ANI was equivalent to that guided by a modified pharmacologic pattern. In a surgical model of mastectomy, the ANI-guided intraoperative administration of fentanyl had no impact on clinical outcomes. Trial registration The study was registered with ClinicalTrials.gov (NCT03716453) on 21/10/2018.

Background: Early goal-directed therapy (EGDT) using the FloTrac system reportedly decreased mortality, morbidity, and length of stay (LOS) in intensive care unit (ICU) and hospital among high-risk patients undergoing non-cardiac surgery. The objective of this study was to evaluate the efficacy of the FloTrac/EV1000 platform for improving postoperative outcomes in cardiac surgery. Methods: Eighty-six adults undergoing coronary artery bypass graft (CABG) with cardiopulmonary bypass (CPB) were randomized to the EV1000 or Control group. The Control group was managed with standard care to achieve the following goals: mean arterial pressure 65-90 mmHg; central venous pressure 8-12 mmHg; urine output ≥ 0.5 mL/kg/h; oxygen saturation > 95%; and hematocrit 26-30%. The EV1000 group was managed to reach similar goals using information from the FloTrac/EV1000 monitor. The targets were: stroke volume variation (SVV) < 13%; cardiac index (CI) 2.2-4.0 L/min/m2; stroke volume index (SVI) 33‑65 mL/beat/m2; and systemic vascular resistance index (SVRI) 1600‑2500 dynes/s/cm5/m2. Results: The LOS in ICU of the EV1000 group was significantly shorter (mean difference -29.5 h; 95%CI -17.2 to -41.8, p < 0.001). The mechanical ventilation time was also shorter in the EV1000 group (mean difference -11.3 h; 95%CI -2.7 to -19.9, p = 0.011). The hospital LOS was shorter in the EV1000 group (mean difference -1.1 d; 95%CI -0.1 to -2.1, p =0.038). The EV1000 group received a higher number of inotropic or vasoactive drugs than the Control group in pre-bypass period, but less in post-bypass, postoperative period before transfer to the ICU, and in the ICU. The EV1000 group had less atrial fibrillation with rapid ventricular response, acute respiratory distress syndrome, and acute renal injury.Conclusions: Compared with standard care, intraoperative hemodynamic optimization using the FloTrac/EV1000 platform for the EGDT protocol in patients undergoing CABG with CPB resulted in shorter ventilator time, shorter ICU and hospital LOS, and fewer postoperative complications. The EV1000 group required more fluid and inotropic or vasoactive drugs in the pre-bypass period to optimize SVV, CI, and SVRI and to maintain the target MAP resulting in better myocardium oxygen supply reflected in fewer drugs required during post-bypass, before transfer to, and in, the ICU.Trial registrationThe study was registered with ClinicalTrials.gov (NCT04292951) on 03/03/2020.

Background Emergency surgery has poor outcomes with high mortality. Numerous studies have reported the risk factors for postoperative death in order to stratify risk and improve perioperative care; nevertheless, a predictive model based upon these risk factors is lacking. Objective We aimed to identify the risk factors of postoperative mortality and to construct a new model for predicting mortality and improving patient care. Methods We included adult patients undergoing emergency surgery at Srinagarind Hospital between January 2012 and December 2014. The patients were randomized: 80% to the Training group for model construction and 20% to the Validation group. Patient data were extracted from medical records and then analyzed using univariate and multivariate logistic regression. Results We recruited 758 patients, and the mortality rate was 14.5%. The Training group comprised 596 patients, and the Validation group comprised 162. Based upon a multivariate analysis in the Training group, we constructed a model to predict postoperative mortality—an Emergency Surgery Mortality (ESM) score based on the coefficient of each risk factor from the multivariate analysis. The ESM score comprised 7 risk factors, i.e., coagulopathy, ASA class 5, bicarbonate <15 mEq/L, heart rate >100/min, systolic blood pressure <90 mmHg, renal comorbidity, and general surgery, for a total score of 11. An ESM score ≥4 was predictive of postoperative mortality with an AUC of 0.83. The respective sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, positive predictive value, negative predictive value, and accuracy for an ESM score ≥4 predictive of postoperative mortality was 70.2%, 94.9%, 13.8, 0.3, 69.4%, 95.1%, and 91.4%. The performance of the ESM score in the Validation group was comparable. Conclusions An ESM score comprises 7 risk factors for a total score of 11. An ESM score ≥4 is predictive of postoperative mortality with a high AUC (0.83), sensitivity (70.2%), and specificity (94.9%). Four risk factors are preoperatively manageable for decreasing the probability of postoperative mortality and improving quality of patient care.