Is atelectasis related to the development of postoperative pneumonia? a retrospective single center study.

BACKGROUND: Atelectasis may play a substantial role in the development of pneumonia. However, pneumonia has never been evaluated as an outcome of atelectasis in surgical patients. We aimed to determine whether atelectasis is related to an increased risk of postoperative pneumonia, intensive care unit (ICU) admission and hospital length of stay (LOS). METHODS: The electronic medical records of adult patients who underwent elective non-cardiothoracic surgery under general anesthesia between October 2019 and August 2020 were reviewed. They were divided into two groups: one who developed postoperative atelectasis (atelectasis group) and the other who did not (non-atelectasis group). The primary outcome was the incidence of pneumonia within 30 days after the surgery. The secondary outcomes were ICU admission rate and postoperative LOS. RESULTS: Patients in the atelectasis group were more likely to have risk factors for postoperative pneumonia including age, body mass index, a history of hypertension or diabetes mellitus and duration of surgery, compared with those in the non-atelectasis. Among 1,941 patients, 63 (3.2%) developed postoperative pneumonia; 5.1% in the atelectasis group and 2.8% in the non-atelectasis (P = 0.025). In multivariable analysis, atelectasis was associated with an increased risk of pneumonia (adjusted odds ratio, 2.33; 95% CI: 1.24 - 4.38; P = 0.008). Median postoperative LOS was significantly longer in the atelectasis group (7 [interquartile range: 5-10 days]) than in the non-atelectasis (6 [3-8] days) (P < 0.001). Adjusted median duration was also 2.19 days longer in the atelectasis group (ß, 2.19; 95% CI: 0.821 - 2.834; P < 0.001). ICU admission rate was higher in the atelectasis group (12.1% vs. 6.5%; P < 0.001), but it did not differ between the groups after adjustment for confounders (adjusted odds ratio, 1.52; 95% CI: 0.88 - 2.62; P = 0.134). CONCLUSION: Among patients undergoing elective non-cardiothoracic surgery, patients with postoperative atelectasis were associated with a 2.33-fold higher incidence of pneumonia and a longer LOS than those without atelectasis. This finding alerts the need for careful management of perioperative atelectasis to prevent or reduce the adverse events including pneumonia and the burden of hospitalizations. TRIAL REGISTRATION: None.

The Effects of Intravenous Fluid Viscosity on the Accuracy of Intravenous Infusion Flow Regulators.

Intravenous infusion flow regulators (IIFRs) are widely used devices but it is unknown how much the difference between the IIFR scale and the actual flow rate depends on the viscosity of the intravenous (IV) fluid. This study evaluated the effects of viscosity on the flow rate of five IV fluids (0.9% normal saline, Hartmann's solution, plasma solution-A, 6% hetastarch, and 5% albumin) when using IIFRs. The viscosity of crystalloids was 1.07-1.12 mPa·s, and the viscosities of 6% hetastarch and 5% albumin were 2.59 times and 1.74 times that of normal saline, respectively. When the IIFR scales were preset to 20, 100, and 250 mL/hr, crystalloids were delivered at the preset flow rate within a difference of less than 10%, while 6% hetastarch was delivered at approximately 40% of the preset flow rates and 5% albumin was approximately 80% transmitted. When delivering colloids, IIFRs should be used with caution.

Reliability of Marked Scales on Intravenous Fluid Plastic Bags.

Precise fluid administration is important to prevent hypo- or hypervolemia. However, the accuracy of scales marked on intravenous (IV) fluid plastic bags had remained unknown. Ten 1 L sized IV crystalloids were prepared from each of three manufacturers (H, J, and D). At each scale, the actual volume of the IV fluid was measured. Differences with the measured volumes for each scale were investigated between the three manufacturers. All initial total volume was greater than 1 L. Except for the full-filled level, H overfilled, whereas J and D filled less. For J and D, the maximal differences between the scale and the measured volume were about 200 mL. Fluid volumes of each scale were significantly different among the three manufacturers (P < 0.001). It is inaccurate to measure the amount of fluid depending on the IV bag scales. Clinicians must use electronic infusion pumps for accurate fluid administration.

Medicosocial Conflict and Crisis due to Illegal Physician Assistant System in Korea.

The Korean Medical Association opposes the illegal attempt to implement the physician assistant (PA) system in Korea. The exact meaning of 'PA' in Korea at present time is 'Unlicensed Assistant (UA)' since it is not legally established in our healthcare system. Thus, PA in Korea refers to unlawful, unqualified, auxiliary personnel for medical practitioners. There have been several issues with the illegal PA system in Korea facing medicosocial conflicts and crisis. Patients want to be diagnosed and treated by medically-educated, licensed and professionally trained physicians not PAs. In clinical settings, PAs deprive the training and educational opportunities of trainees such as interns and residents. Recently, there have been several attempts, by CEO or directors of major hospitals in Korea, to adopt and legalize this system without general consensus from medical professional associations and societies. Without such consensus, this illegal implementation of PA system will create new and additional very serious medical crises due to unlawful medical, educational, professional conflicts and safety issues in medical practice. Before considering the implementation of the PA system, there needs to be a convincing justification by solving the fundamental problems beforehand, such as the collapsed medical delivery system, protection and provision of optimal education program and training environment of trainees, burnout from excessive workloads of physicians with very low compensational system and poor conditions for working and education, etc.

A Meta-Analysis of Renal Function After Adult Cardiac Surgery With Pulsatile Perfusion.

The aim of this meta-analysis was to determine whether pulsatile perfusion during cardiac surgery has a lesser effect on renal dysfunction than nonpulsatile perfusion after cardiac surgery in randomized controlled trials. MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were used to identify available articles published before April 25, 2014. Meta-analysis was conducted to determine the effects of pulsatile perfusion on postoperative renal functions, as determined by creatinine clearance (CrCl), serum creatinine (Cr), urinary neutrophil gelatinase-associated lipocalin (NGAL), and the incidences of acute renal insufficiency (ARI) and acute renal failure (ARF). Nine studies involving 674 patients that received pulsatile perfusion and 698 patients that received nonpulsatile perfusion during cardiopulmonary bypass (CPB) were considered in the meta-analysis. Stratified analysis was performed according to effective pulsatility or unclear pulsatility of the pulsatile perfusion method in the presence of heterogeneity. NGAL levels were not significantly different between the pulsatile and nonpulsatile groups. However, patients in the pulsatile group had a significantly higher CrCl and lower Cr levels when the analysis was restricted to studies on effective pulsatile flow (P < 0.00001, respectively). The incidence of ARI was significantly lower in the pulsatile group (P < 0.00001), but incidences of ARF were similar. In conclusion, the meta-analysis suggests that the use of pulsatile flow during CPB results in better postoperative renal function.

A meta-analysis of pulmonary function with pulsatile perfusion in cardiac surgery.

The aim of this study was to determine whether pulsatile or nonpulsatile perfusion had a greater effect on pulmonary dysfunction in randomized controlled trials. MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were used to identify available articles published before April 13, 2013. A meta-analysis was conducted on the effects of pulsatile perfusion on postoperative pulmonary function, intubation time, and the lengths of intensive care unit (ICU) and hospital stays. Eight studies involving 474 patients who received pulsatile perfusion and 496 patients who received nonpulsatile perfusion during cardiopulmonary bypass (CPB) were considered in the meta-analysis. Patients receiving pulsatile perfusion had a significantly greater PaO2 /FiO2 ratio 24 h and 48 h post-operation (P < 0.00001, both) and significantly lower chest radiograph scores at 24 h and 48 h post-operation (P < 0.00001 and P = 0.001, respectively) compared with patients receiving nonpulsatile perfusion. The incidence of noninvasive ventilation for acute respiratory insufficiency was significantly lower (P < 0.00001), and intubation time and ICU and hospital stays were shorter (P = 0.004, P < 0.00001, and P < 0.00001, respectively) in patients receiving pulsatile perfusion during CPB compared with patients receiving nonpulsatile perfusion. In conclusion, our meta-analysis suggests that the use of pulsatile flow during CPB results in better postoperative pulmonary function and shorter ICU and hospital stays.

Meta-Analysis of Sodium Bicarbonate Therapy for Prevention of Cardiac Surgery-Associated Acute Kidney Injury.

OBJECTIVE: The aim of this study was to determine whether or not perioperative administration of sodium bicarbonate had a preventive effect on cardiac surgery-associated acute kidney injury (CSA-AKI) as shown in randomized controlled trials. DESIGN: The authors conducted a systematic review and meta-analysis using MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), and KoreaMed. SETTING: The authors searched MEDLINE, EMBASE, CENTRAL, and KoreaMed without language and date restrictions. They used both MeSH and free-text terms to identify relevant studies. Electronic searches were undertaken on July 31, 2014. PARTICIPANTS: Five randomized controlled studies included in this review. MEASUREMENTS AND MAIN RESULTS: There were no differences in the development of CSA-AKI among patients in the sodium bicarbonate group compared with those in the control group (5 trials, 1,092 patients; n = 233 of 547 in sodium bicarbonate (SB) group versus 225 of 545 in control group (SC); risk ratio (RR), 0.95; 95% confidence interval (CI), 0.74-1.22. Also, there were no statistical differences in in-hospital mortality (3 trials, 573 patients; n = 21 of 288 in SB versus 14 of 285 in SC; RR, 1.44; 95% CI, 0.76-2.72), need for renal replacement therapy (4 trials, 1,000 patients; n = 21 of 503 in SB versus 23 of 497 in SC; RR, 0.90; 95% CI, 0.50-1.60), length of stay in the intensive care unit (ICU) (hours) (4 trials, n = 969 patients, weighted men difference (WMD), 2.17; 95% CI, -1.15-5.49), and length of ventilation (hours) (4 trials, 969 patients; WMD, 0.34; 95% CI,-0.80-1.48). CONCLUSIONS: Perioperative administration of sodium bicarbonate did not reduce the rate of CSA-AKI in randomized controlled trials. Therefore, use of perioperative administration of sodium bicarbonate for the prevention of CSA-AKI is questionable.

Effects of Remimazolam versus Sevoflurane on Hemodynamics in Patients Undergoing Coil Embolization of Cerebral Aneurysm: A Prospective Randomized Controlled Trial.

Background: Cerebral aneurysm coil embolization is often performed under general anesthesia to prevent patient movement and sudden high blood pressure. However, the optimal anesthetic agent remains uncertain. This study aimed to determine whether maintaining anesthesia with remimazolam in patients undergoing coil embolization could avoid hypotension or hypertension compared to sevoflurane. Methods: Thirty-three adult patients participated in this single-blinded, randomized controlled trial. Patients in Group R were induced and maintained with remimazolam, whereas those in Group S received propofol and sevoflurane. Results: The use of remimazolam significantly reduced the incidence of intraoperative hypotension events (33.3% vs. 80.0%; p = 0.010) but did not change the incidence of hypertension events (66.7% vs. 73.3%; p = 0.690). Patients in Group R maintained a significantly higher range of maximal (100.2 ± 16.6 vs. 88.1 ± 13.5 mmHg; p = 0.037) and minimal (69.4 ± 6.6 vs. 63.4 ± 4.8 mmHg; p = 0.008) mean arterial blood pressure than those in Group S during the intervention. Conclusions: This is the first study to demonstrate the feasibility of maintaining general anesthesia with remimazolam in patients undergoing cerebral aneurysm coil embolization. The findings suggest that remimazolam may maintains better hemodynamic stability, reducing the incidence of hypotensive events without compromising patient safety.

Effects of video-assisted preanesthetic patient education on preanesthetic interview time; A prospective, single-blinded, randomized controlled trial.

BACKGROUND: A preanesthetic evaluation interview with an anesthesiologist is essential for patient safety, however, it is not performed adequately owing to the excessive workload of doctors. This study aimed to determine whether video-assisted preanesthetic patient education can reduce patient interview time and solve the problem of excessive labor at a relatively low cost. METHODS: This study considered relatively healthy patients aged 19 to 65 years who were scheduled for elective surgery under general anesthesia. None of the patients had history of general anesthesia. Patients were randomly assigned 1:1 to Groups V and C. Group V watched the preanesthetic education video, while Group C did not. The duration of the preanesthetic evaluation interview was measured for all participants. The satisfaction of the anesthesiologist and patient with the preanesthetic evaluation procedure, anxiety of the patient, and vital signs during surgery were collected. RESULTS: A total of 33 patients in Group V watched the preanesthetic education video, while 31 patients in Group C did not. Group V spent significantly less time on the preanesthetic evaluation interview with an anesthesiologist than that of Group C (172.42 vs 196.68 seconds; P = .005). There was no difference in patient and anesthesiologist satisfaction between the 2 groups (P = .861 and P = .849, respectively). Patients' anxiety (P = .474), intraoperative mean blood pressure (P = .168), and heart rate (P = .934) did not differ between Groups V and C. CONCLUSION: Watching the informational video about anesthesia before preanesthetic evaluation could reduce the interview time by an average of 24 seconds, with no difference in patients' or doctors' satisfaction or anxiety compared to patients who did not watch it. Video-assisted preanesthetic patient education indicates that the load on anesthesiologists can be reduced.

In vitro effect of clinical propofol concentrations on platelet aggregation.

The inhibitory effect of propofol on platelet aggregation remains unclear, and studies on the subject disagree. Furthermore, although propofol infusions are widely used for general anesthesia and as sedatives for patients in intensive care units, little information is available on its concentration- and time-related effects on platelet aggregation. Here, the authors investigated the in vitro effect of propofol, at concentrations required for sedation and general anesthesia, on platelet aggregation after 1, 2, or 3 h. Blood from healthy volunteers (n = 9) was incubated at propofol plasma concentrations of 0, 2, 4, and 10 µg/mL in a water bath at 37°C. Platelet aggregation was measured using a platelet function analyzer (PFA-100) after 1, 2, or 3 h of incubation. Times to occlude collagen/epinephrine (CEPI) or collagen/adenosine 5'-diphosphate (CADP)-coated membranes (closure times, CTs) were measured. The CEPI and CADP CTs of non-incubated blood were 125.6 ± 19.5 s and 93.0 ± 12.2 s, respectively, and no significant difference in CEPI CTs was observed at propofol plasma concentrations of 0, 2, 4, and 10 µg/mL after incubation for 1, 2, or 3 h. CADP CTs were comparable at propofol concentrations of 0, 2, 4, and 10 µg/mL at each incubation time. These findings suggest that propofol at concentrations required for sedation and general anesthesia has no inhibitory effect on platelet aggregation after 3 h of incubation.

Limited effect of sugammadex on postoperative pulmonary complications in patients undergoing spine surgery in prone position intraoperatively: A retrospective analysis of matched cohort data.

Postoperative pulmonary complications (PPCs) increase postoperative mortality, hospital stays, and healthcare costs. Whether the use of sugammadex could reduce PPCs remains controversial. This study aimed to determine if sugammadex could more effectively reduce PPCs than acetylcholinesterase inhibitor (AChEi) in patients who had undergone spine surgery, in prone position intraoperatively. From March 2019 to February 2021, adult patients who underwent elective spine surgery were eligible. Primary outcomes were PPCs (including atelectasis on chest radiograph, pneumonia, acute respiratory distress syndrome, and aspiration pneumonitis) and respiratory failure that occurred within 28 days after surgery. Secondary outcomes were length of hospital stay, in-hospital death, and readmission rate within 30 days. Patients were divided into 2 groups (Sugammadex group and AChEi group) and compared by 1:1 propensity score matching. Of a total of 823 patients who underwent spinal surgery, 627 were included. After 1:1 propensity matching, 142 patients were extracted for each group. PPCs occurred in 9 (6.3%) patients in both groups (P = 1.000). Respiratory failure occurred in 7 (4.9%) patients in the Sugammadex group and 5 (3.5%) patients in the AChEi group (P = .77). There was no significant difference in secondary outcomes between the 2 groups. Although there have been some evidences showing that the use of sugammadex can attenuate the development of PPCs, this study did not show positive effects of sugammadex on patients who underwent spine surgery in the prone position.

Lung ultrasound score-based assessment of postoperative atelectasis in obese patients according to inspired oxygen concentration: A prospective, randomized-controlled study.

BACKGROUND: According to a recent meta-analysis, in patients with a body mass index (BMI) ≥ 30, a high fraction of inhaled oxygen (FiO2) did not increase postoperative atelectasis. However, a high FiO2 generally increases the risk of postoperative atelectasis. Therefore, this study aimed to evaluate the effect of FiO2 on the development of atelectasis in obese patients using the modified lung ultrasound score (LUSS). METHODS: Patients were assigned to 4 groups: BMI ≥ 30: group A (n = 21) and group B (n = 20) and normal BMI: group C (n = 22) and group D (n = 21). Groups A and C were administered 100% O2 during preinduction and emergence and 50% O2 during anesthesia. Groups B and D received 40% O2 for anesthesia. The modified LUSS was assessed before and 20 min after arrival to the postanesthesia care unit (PACU). RESULTS: The difference between the modified LUSS preinduction and PACU was significantly higher in group A with a BMI ≥ 30 (P = .006); however, there was an insignificant difference between groups C and D in the normal BMI group (P = .076). CONCLUSION: High FiO2 had a greater effect on the development of atelectasis in obese patients than did low FiO2; however, in normal-weight individuals, FiO2 did not have a significant effect on postoperative atelectasis.

Impact of preoperative red blood cell transfusion on long-term mortality of liver transplantation: A retrospective cohort study.

Preoperative red blood cell (RBC) transfusion can induce immune modulation and alloimmunization; however, few studies have investigated the effect of preoperative transfusion and hemoglobin levels that need to be corrected before surgery, especially in critically ill patients such as those with end-stage liver disease who undergo liver transplantation (LT). This study aimed to investigate the effects of preoperative RBC transfusion on long-term mortality in LT recipients. A total of 249 patients who underwent LT at a single center between January 2012 and December 2021 were included in this study. The patients were divided into 2 groups: preoperative transfusion and preoperative non-transfusion. Since the baseline characteristics were significantly different between the 2 groups, we performed propensity score matching, including factors such as the Model for End-Stage Liver Disease score and intraoperative RBC transfusion, to exclude possible biases that could affect prognosis. We analyzed the 5-year mortality rate as the primary outcome. The preoperative transfusion group showed a 4.84-fold higher hazard ratio than that in the preoperative non-transfusion group. There were no differences in 30-day mortality, duration of intensive care unit stay, or graft rejection rate between the 2 groups. Preoperative transfusion could influence long-term mortality in LT, and clinicians should pay attention to RBC transfusion before LT unless the patient is hemodynamically unstable. A large-scale randomized controlled trial is needed to determine the possible mechanisms related to preoperative RBC transfusion, long-term mortality, and the level of anemia that should be corrected before surgery.

Short-Term and Long-Term Effects of Ischemic Conditioning on Liver Transplantation: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

BACKGROUND: Although liver transplantation (LT) is one of the definitive treatments for patients with end-stage liver failure, it inevitably results in ischemic reperfusion injury. It is known that prognosis is improved when temporary ischemic conditioning (IC) is applied to patients with ischemic reperfusion injury. The objective of this meta-analysis was to determine the short-term and long-term effects of IC on the clinical outcomes of LT recipients. METHODS: Randomized controlled studies on IC in patients with LTs were included. Patients were compared between an IC group and a sham group. Studies were retrieved from PubMed, Embase, and Cochrane Library. The risk of bias was evaluated using RoB 2.0. Mortality, graft function, and major complications were synthesized using RevMan 5.4.1. RESULTS: Among 316 papers, 17 articles (1196 patients) were included. There was an insignificant increase in short-term mortality (risk ratio [RR]: 3.00, 95% CI: 0.32-28.14, P = .34). However, long-term mortality was lower in the IC group than in the sham group, but not significantly (RR: 0.75; 95% CI: 0.47-1.20, P = .23). Short-term graft function (acute graft rejection and primary graft non-function) was not improved by IC. One-year graft loss tended to show better results in the IC group (RR: 0.53, 95% CI: 0.26-1.07, P = .08). CONCLUSION: Ischemic conditioning did not have a beneficial effect on LT. Although long-term outcomes appear to be better in the IC group than in the sham group, further randomized controlled trials are needed.

Effects of perioperative erythropoietin administration on acute kidney injury and red blood cell transfusion in patients undergoing cardiac surgery: A systematic review and meta-analysis.

BACKGROUND: The renoprotective effects of erythropoietin (EPO) are well-known; however, the optimal timing of EPO administration remains controversial. Red blood cell (RBC) transfusion is an independent risk factor for cardiac surgery-associated acute kidney injury (CSA-AKI). We aimed to evaluate the efficacy of EPO on CSA-AKI and RBC transfusion according to the timing of administration. METHODS: We searched the Cochrane Library, EMBASE, and MEDLINE databases for randomized controlled trials. The primary outcome was the incidence of CSA-AKI following perioperative EPO administration, and the secondary outcomes were changes in serum creatinine, S-cystatin C, S-neutrophil gelatinase-associated lipocalin, urinary neutrophil gelatinase-associated lipocalin, length of hospital and intensive care unit (ICU) stay, volume of RBC transfusion, and mortality. The subgroup analysis was stratified according to the timing of EPO administration in relation to surgery. RESULTS: Eight randomized controlled trials with 610 patients were included in the study. EPO administration significantly decreased the incidence of CSA-AKI (odds ratio: 0.60, 95% confidence interval [CI]: 0.43-0.85, P = .004; I2 = 52%; P for heterogeneity = .04), intra-operative RBC transfusion (standardized mean difference: -0.30, 95% CI: -0.55 to -0.05, P = .02; I2 = 15%, P for heterogeneity = .31), and hospital length of stay (mean difference: -1.54 days, 95% CI: -2.70 to -0.39, P = .009; I2 = 75%, P for heterogeneity = .001) compared with control groups. Subgroup analyses revealed that pre-operative EPO treatment significantly reduced the incidence of CSA-AKI, intra-operative RBC transfusion, serum creatinine, and length of hospital and ICU stay. CONCLUSION: Pre-operative administration of EPO may reduce the incidence of CSA-AKI and RBC transfusion, but not in patients administered EPO during the intra-operative or postoperative period. Therefore, pre-operative EPO treatment can be considered to improve postoperative outcomes by decreasing the length of hospital and ICU stay in patients undergoing cardiac surgery.

Increase in body temperature in pediatric patients after costal cartilage harvest in microtia reconstruction: A retrospective observational study.

BACKGROUND: Previous evidence has clearly shown that maintaining normothermia in children undergoing surgery is difficult and is associated with adverse outcomes. Therefore, this study aimed to retrospectively analyze the changes in body temperature over time in 2 different types of microtia reconstruction surgeries, namely, embedding, and elevation surgeries. METHODS: We performed a retrospective chart review of patients who underwent microtia reconstruction (embedding and elevation) between July 2012 and February 2015 (n = 38). The changes in body temperature between the 2 types of surgeries were compared. RESULTS: During microtia reconstruction, the body temperature in the embedding surgery group was significantly higher than that in the elevation surgery group from 1 hour after the start of surgery to 1 day after the surgery (P < .001). Time, group, and time-group interaction were associated with an increase in body temperature (P < .001) but not the warming method. CONCLUSION: We found an increase in body temperature in patients with microtia who underwent embedding surgery (autologous costal cartilage harvest surgery), and this was related to the type of surgery and not to the warming method. Therefore, further research is warranted to determine the cause of the increase in body temperature during this surgery.

A durability study of a paracorporeal pulsatile electro-mechanical pneumatic biventricular assist device.

In 2002, the paracorporeal pulsatile electro-mechanical pneumatic ventricular assist device (VAD) began to be developed by the Korea Artificial Organ Center at Korea University under a Health & Medical Technology Research and Development program which finished in 2008. In vitro durability testing was conducted on the paracorporeal pulsatile pneumatic VAD to determine device durability and to evaluate device failures. The 1- and 2-year reliability of the paracorporeal pulsatile pneumatic VAD was shown to be 91.2% and 54.9%, respectively, with an 80% confidence level. Failure modes were analyzed using fault tree analysis, with customized software continuously acquiring data during the test period. After this period, 21 in vivo animal tests were done, with 14 cases of left atrium to left ventricle (LV) inflow cannulation (36Fr)/outflow grafting to descending aorta, and seven cases of apex cannulation of LV to descending aorta (12 mm). The longest postoperative day (182 days) in Korea was recently recorded in in vivo animal testing (bovine, 90 kg, male, 3.5-4.0 L/min flow rate, and 55 bpm).

Effects of remote ischemic preconditioning on the deformability and aggregation of red blood cells in a rat endotoxemia model.

BACKGROUND: The prevention of rheologic alterations in erythrocytes may be important for reducing sepsis-associated morbidity and mortality. Remote ischemic preconditioning (RIPC) has been shown to prevent tissue damage caused by severe ischemia and mortality resulting from sepsis. However, the effect of RIPC on erythrocytes in sepsis is yet to be determined. OBJECTIVE: To investigate the effect of RIPC on rheologic alterations in erythrocytes in sepsis. METHODS: Thirty male Sprague-Dawley rats were used in this study. An endotoxin-induced sepsis model was established by intraperitoneally injecting 20 mg/kg LPS (LPS group). RIPC was induced in the right hind limb using a tourniquet, with three 10-minute of ischemia and 10 min of reperfusion cycles immediately before the injection of LPS (RIPC/LPS group) or phosphate-buffered saline (RIPC group). The aggregation index (AI), time to half-maximal aggregation (T1/2), and maximal elongation index (EImax) of the erythrocytes were measured 8 h after injection. RESULTS: The AI, T1/2, and EImax values in the LPS and RIPC/LPS groups differed significantly from those in the RIPC group, but there were no differences between the values in the LPS and RIPC/LPS groups. CONCLUSIONS: RIPC did not prevent rheologic alterations in erythrocytes in the rat model of LPS-induced endotoxemia.

Effects of high versus low inspiratory oxygen fraction on postoperative clinical outcomes in patients undergoing surgery under general anesthesia: A systematic review and meta-analysis of randomized controlled trials.

OBJECTIVES: To determine whether high perioperative inspired oxygen fraction (FiO2) compared with low FiO2 has more deleterious postoperative clinical outcomes in patients undergoing non-thoracic surgery under general anesthesia. DESIGN: Meta-analysis of randomized controlled trials. SETTING: Operating room, postoperative recovery room and surgical ward. PATIENTS: Surgical patients under general anesthesia. INTERVENTION: High perioperative FiO2 (≥0.8) vs. low FiO2 (≤0.5). MEASUREMENTS: The primary outcome was mortality within 30 days. Secondary outcomes were pulmonary outcomes (atelectasis, pneumonia, respiratory failure, postoperative pulmonary complications [PPCs], and postoperative oxygen parameters), intensive care unit (ICU) admissions, and length of hospital stay. A subgroup analysis was performed to explore the treatment effect by body mass index (BMI). MAIN RESULTS: Twenty-six trials with a total 4991 patients were studied. The mortality in the high FiO2 group did not differ from that in the low FiO2 group (risk ratio [RR] 0.91, 95% confidence interval [CI] 0.42-1.97, P = 0.810). Nor were there any significant differences between the groups in such outcomes as pneumonia (RR 1.19, 95% CI 0.74-1.92, P = 0.470), respiratory failure (RR 1.29, 95% CI 0.82-2.04, P = 0.270), PPCs (RR 1.05, 95% CI 0.69-1.59, P = 0.830), ICU admission (RR 0.94, 95% CI 0.55-1.60, P = 0.810), and length of hospital stay (mean difference [MD] 0.27 d, 95% CI -0.28-0.81, P = 0.340). The high FiO2 was associated with postoperative atelectasis more often (risk ratio 1.27, 95% CI 1.00-1.62, P = 0.050), and lower postoperative arterial partial oxygen pressure (MD -5.03 mmHg, 95% CI -7.90- -2.16, P < 0.001). In subgroup analysis of BMI >30 kg/m2, these parameters were similarly affected between the groups. CONCLUSIONS: The use of high FiO2 compared to low FiO2 did not affect the short-term mortality, although it may increase the incidence of atelectasis in adult, non-thoracic patients undergoing surgical procedures. Nor were there any significant differences in other secondary outcomes.

A Comparison of Anesthetic Quality Between Interscalene Block and Superior Trunk Block for Arthroscopic Shoulder Surgery: A Randomized Controlled Trial.

BACKGROUND: Interscalene block is the most commonly used nerve block for shoulder surgery, and superior trunk block has been investigated as a phrenic-sparing alternative. This randomized controlled trial compared ultrasound-guided interscalene block and superior trunk block as anesthesia for arthroscopic shoulder surgery. OBJECTIVES: Our aims were to determine the superiority of anesthesia quality and compare the risk of hemidiaphragmatic paralysis between these 2 blocks. STUDY DESIGN: A randomized, controlled trial. SETTING: Department of Anesthesiology and Pain Medicine, Korea University Anam Hospital. METHODS: Forty-eight patients undergoing elective arthroscopic shoulder surgery under an ultrasound guided brachial plexus block were randomized to receive either an interscalene block (ISB group, n = 24) or a superior trunk block (STB group, n = 24) for surgery. Ten milliliters of 2% lidocaine and 10 mL of 0.75% ropivacaine were used as local anesthesia in both brachial plexus block groups (total 20 mL). In the ISB group, the local anesthesia was injected between the C5-C6 root and at the upper part of C5 with equally divided doses. In the STB group, the local anesthesia was injected into the anterior and posterior parts of the superior trunk with equally divided doses. Sensory blockade of each trocar's insulting site (supraclavicular, axillary, and suprascapular nerve areas) and motor blockade of the axillary nerve (shoulder abduction) and the suprascapular nerve (shoulder external rotation) were assessed by a blinded observer at 5-minute intervals for 30 minutes after the block. Anesthesia quality was assessed using 3 grades (excellent/insufficient/failure). The blinded investigator also assessed the grade of hemidiaphragmatic paralysis (normal/partial/complete) by comparing pre- and postoperative chest radiographs. Primary outcome variables were anesthesia grade and rate of hemidiaphragmatic paralysis. Secondary outcome variables were performance time and anesthesia onset time. RESULTS: The anesthetic grade was significantly different between the 2 groups (22/2/0 in the ISB group vs. 16/3/5 in the STB group, P = 0.046). Both groups displayed equivalent incidence of hemidiaphragmatic paralysis (12/6/6 in the ISB group vs. 7/14/3 in the STB group, P = 0.063). No intergroup differences were found in terms of performance time and anesthesia onset time. LIMITATIONS: Our sensory and motor function test was not applied to the subscapular nerve, which serves internal rotation of the humeral head so may be difficult to evaluate in patients with rotator cuff tears. We assessed the diaphragmatic movement by chest radiographs instead of by ultrasound. CONCLUSIONS: The superior trunk block provided lower quality of surgical anesthesia than the interscalene block and did not effectively decrease the risk of hemidiaphragmatic paralysis during arthroscopic shoulder surgery for rotator cuff syndrome.