Evaluation of Factors Affecting Illumination Intensity in Lightwand Endotracheal Intubation.

BACKGROUND/AIM: A lightwand is a stylet with a light bulb at its tip that can be used to guide intubation by confirming the illumination through the anterior neck. We aimed to determine the factors affecting the illumination intensity during lightwand endotracheal intubation. PATIENTS AND METHODS: We retrospectively collected data from 180 patients who underwent lightwand endotracheal intubation. We recorded illumination intensity on a 5-point scale. The patients were categorized into weak (score <3) and bright (score ≥3) groups based on the illumination intensity scale score. RESULTS: A total of 176 patients were analyzed, of whom 125 (71.1%) were enrolled in the bright group, and 51 (29.0%) were enrolled in the weak group. Multivariable logistic regression analysis revealed that an increased body mass index (BMI) and mask ventilation grade were associated with light intensity. For mask ventilation, moderate vs. easy (p=0.010) and difficult vs. easy (p=0.008) were associated with the weak group. Receiver operating characteristic curve analysis showed that BMI ≥24.6 kg/m2 was correlated with the weak group. CONCLUSION: BMI ≥24.6 kg/m2 or mask ventilation grade above moderate indicates increased odds of weak illumination intensity in lightwand intubation. Pre-intubation examination of these factors helps increase the chances of successful intubation.

Effects of infusion tubing line lengths and syringe sizes on infusion system compliance: an experimental study using a syringe-type infusion pump at low flow rate.

Ideally, the flow delivery of an infusion system is proportional only to the rate of mechanical actuation of the syringe pump plunger. However, in the real world, overall infusion system compliance may be affected by components such as an extension of tubing lines, or different sizes of syringes. With higher compliance, there may be greater chances of flow irregularity. In this experimental study, we investigated the effects of lengths of infusion lines and syringe sizes on the compliance of syringe pumps with low flow rate (2 ml h-1). In the first experiment, infusion system compliance was measured in various settings by occlusion release. As the infusion tubing length and size of the syringe increased, the time to reach each pressure was delayed and the infusion system compliance increased. The contributions to system compliance from syringes were significantly greater compared to those of extended infusion lines. In the occlusion alarm experiment, the occlusion alarm could be delayed by 69.76 ± 3.98 min for the 50-ml syringe with a 560 cm infusion line set-up. In conclusion, the compliance of a syringe pump system increases as the loaded syringe size, or the length of the infusion tubing increases. The occlusion alarm may be much delayed and not useful in highly compliant systems with respect to the potential occlusion of the infusion system, so more attention is required when using a highly compliant infusion system.

Risk factors for femoral-to-radial artery pressure gradient after weaning from cardiopulmonary bypass: a historical cohort study.

PURPOSE: After weaning from cardiopulmonary bypass (CPB), the radial artery pressure is frequently lower than the central pressure as reflected by femoral pressure. This discrepancy may cause improper blood pressure management. In this study, we aimed to evaluate the risk factors related to developing a significant postbypass femoral-to-radial pressure gradient, including the incidence of complications related to femoral pressure monitoring. METHODS: From January 2017 to May 2021, we studied consecutive adult cardiovascular surgical patients undergoing CPB in a historical cohort study. Patients were divided into two groups according to developing a significant femoral-to-radial pressure gradient, which was defined as a difference of ≥ 25 mm Hg for systolic pressure or ≥ 10 mm Hg for mean pressure, lasting ≥ 5 minutes for 30 minutes after CPB weaning. Factors associated with a significant pressure gradient and femoral pressure monitoring-related complications were analyzed. RESULTS: Among 2,019 patients, 677 (34%) showed a significant postbypass femoral-to-radial pressure gradient. Multivariable logistic regression analysis revealed the following factors related to the pressure gradient development: age (adjusted odds ratio [aOR] for an increase in 10 years, 1.09; 95% confidence interval [CI], 1.04 to 1.09; P < 0.001), body surface area (BSA) (aOR for an increase in 1 m2, 0.12; 95% CI, 0.07 to 0.21; P < 0.001), aortic cross-clamping time (aOR for an increase in 30 minutes, 1.05; 95% CI, 1.03 to 1.08; P < 0.001), and intraoperative epinephrine use (aOR, 1.55; 95% CI, 1.23 to 1.95; P < 0.001). The femoral pressure monitoring-related complications were observed in 11/2,019 (0.5%) patients. CONCLUSION: Our study showed that old age, smaller BSA, prolonged aortic cross-clamping time, and intraoperative epinephrine use were associated with developing a significant postbypass femoral-to-radial pressure gradient in cardiovascular surgery. Considering monitoring-related complications occurred very infrequently, it might be helpful to monitor both radial and femoral pressure simultaneously in patients with these risk factors for appropriate blood pressure management. Nevertheless, further studies are needed to confirm our findings because our results are limited by a retrospective design and residual confounding factors.

RéSUMé: OBJECTIF: Après le sevrage de la circulation extracorporelle (CEC), la pression dans l'artère radiale est souvent inférieure à la pression centrale, comme en témoigne la pression fémorale. Cette divergence peut provoquer une gestion inadaptée de la tension artérielle. Dans cette étude, nous avons cherché à évaluer les facteurs de risque liés au développement d'un gradient de pression significatif fémoro-radial post CEC, y compris l'incidence des complications liées à la surveillance de la pression fémorale. MéTHODES: Nous avons étudié consécutivement, de janvier 2017 à mai 2021, des patients adultes de chirurgie cardiovasculaire subissant une CEC dans une étude de cohorte historique. Les patients ont été séparés en deux groupes en fonction de la survenue d'un gradient de pression fémoro-radial significatif qui était défini ainsi : différence de ≥ 25 mmHg pour la pression systolique ou ≥ 10 mmHg pour la pression moyenne, durant ≥ 5 minutes pendant les 30 minutes suivant le sevrage de la CEC. Les facteurs associés à un gradient de pression significatif et aux complications liées à la surveillance de la pression fémorale ont été analysés. RéSULTATS: Parmi les 2 019 patients, 677 (34 %) ont présenté un gradient de pression fémoro-radial significatif post CEC. Une analyse par régression logistique multifactorielle a révélé que les facteurs suivants étaient liés à la survenue du gradient de pression : l'âge (rapport de cotes ajusté [aOR] pour une augmentation en dix ans, 1,09; intervalle de confiance [IC] à 95 % : 1,04 à 1,09; P < 0,001), la surface corporelle (SC) (aOR pour une augmentation dans 1 m2, 0,12; IC à 95 %, 0,07 à 0,21; P < 0,001), la durée du clampage aortique (aOR pour une augmentation en 30 minutes, 1,05; IC à 95 %, 1,03 à 1,08; P < 0,001) et l'utilisation peropératoire d'épinéphrine (aOR, 1,55; IC à 95 %, 1,23 à 1,95; P < 0,001). Des complications liées à la surveillance de la pression fémorale ont été observées chez 11 patients sur 2019 (0,5 %). CONCLUSION: Notre étude a montré qu'un âge avancé, une petite SC, une durée prolongée de clampage aortique et l'utilisation peropératoire d'épinéphrine étaient associés à la survenue d'un gradient de pression fémoro-radial significatif en chirurgie cardiovasculaire. Considérant que les complications liées à la surveillance ont été très rares, il pourrait être utile de surveiller simultanément la pression radiale et la pression fémorale chez les patients ayant ces facteurs de risque pour une gestion appropriée de la pression artérielle. Néanmoins, d'autres études sont nécessaires pour confirmer nos constatations, car ces résultats sont limités par le plan rétrospectif de l'étude et des facteurs confondants résiduels.

Simulation Analysis of Flow Rate Variability During Microinfusions: The Effect of Vertical Displacement and Multidrug Infusion in Conventional Infusion Pumps Versus New Cylinder-Type Infusion Pumps.

BACKGROUND: Medication dosing errors can occur during microinfusions when there is vertical pump displacement or multidrug infusion through a single intravenous path. We compared flow rate variability between new-generation cylinder-type infusion pumps and conventional infusion pumps under simulated conditions. METHODS: We evaluated the flow rates during microinfusions using different infusion pumps (syringe pump with 10/30/50-mL syringes, peristaltic pump, and cylinder pump). Two visible dyes were used as model drugs. The study samples were quantified using spectrophotometry. For vertical displacement, the infusion pumps were moved up and down by 60 cm during microinfusions at 0.5 mL·h-1 and 2 mL·h-1. In the multi-infusion study, the second drug flow was added through 4 linearly connected stopcocks either upstream or downstream of the first drug. We compared the total error dose between the cylinder pump and the syringe pump with a Mann-Whitney U test and additionally estimated the effects of the infusion pumps on total error doses by linear regression analysis. RESULTS: There were repetitive patterns of temporary flow increases when the pump was displaced upward and flow decreases when the pump was displaced downward in all settings. However, the amount of flow irregularities was more pronounced at the lower infusion rate and in the syringe-type pump using larger volume syringes. The total error dose increased in the syringe pump loaded with a 50-mL syringe compared to that of the new cylinder pump (regression coefficient [ß] = 4.66 [95% confidence interval {CI}, 1.60-7.72]; P = .008). The initiation and cessation of a new drug during multidrug microinfusion in the same intravenous path affected the lower rate first drug leading to a transient flow rate increase and decrease, respectively. The change in flow rate was observed regardless of the port selected for addition of the second drug, and the total error dose of the first drug did not significantly vary when an upstream or a downstream port was selected. CONCLUSIONS: In the microinfusion settings, attention must be paid to the use of the syringe pump loaded with large-volume syringes. The novel cylinder pump could be considered as a practical alternative to syringe pumps with small syringes given its flow stability without the need for frequent drug replacement.

The efficacy of ultrasound-guided erector spinae plane block after mastectomy and immediate breast reconstruction with a tissue expander: a randomized clinical trial.

BACKGROUND: We aimed to investigate the analgesic efficacy of an erector spinae plane block (ESPB) in immediate breast reconstruction (IBR) with a tissue expander. METHODS: Adult women undergoing IBR with a tissue expander after mastectomy were randomly assigned to either intravenous patient-controlled analgesia (IV-PCA) alone (group P) or IV-PCA plus ESPB (group E). The primary outcome was the total amount of opioid consumption during 24 hours postoperatively between the two groups. Secondary outcomes were patient satisfaction, pain score at rest and on shoulder movement using numerical rating scale, incidences of postoperative nausea and vomiting (PONV), and a short form of the brief pain inventory (BPI-SF) at 3 and 6 months after surgery between the groups. RESULTS: Fifty eight patients completed the study. At 24 hours postoperatively, total opioid consumption was significantly less in group E than in group P (285.0 ± 92.0, 95% confidence interval [CI]: 250.1 to 320.0 vs. 223.2 ± 83.4, 95% CI: 191.5 to 254.9, P = 0.005). Intraoperative and cumulative PCA fentanyl consumption at 3, 6, 9, and 24 hours were also less in group E than in group P (P = 0.004, P = 0.048, P = 0.020, P = 0.036, and P < 0.001, respectively). Patient satisfaction was higher in group E (6.9 ± 1.8 vs. 7.8 ± 1.4, P = 0.042). The incidences of PONV was similar. CONCLUSIONS: The ESPB decreased postoperative opioid consumption and increased patient satisfaction without significant complications after IBR with a tissue expander after mastectomy.

Simulation study on flow rate accuracy of infusion pumps in vibration conditions during emergency patient transport.

Infusion pumps are frequently used when transferring critically ill patients via patient transport cart, ambulance, or helicopter. However, the performance of various infusion pumps under these circumstances has not been explored. The aim of this study was to evaluate the flow rate accuracy of infusion pumps under various clinical vibration conditions. Experiments were conducted with four different types of pumps, including two conventional syringe pumps (Injectomat MC Agilia, Fresenius Kabi and TE-331, Terumo), one conventional peristaltic pump (Volumed µVP7000; Arcomed), and one new cylinder pump (H-100, Meinntech). The flow rate was measured using an infusion pump analyzer on a stable table (0 m/s2) for 1 h with 1 ml/h and 5 ml/h. Experiments were repeated in mild vibration (2 m/s2) (representing vibration of patients in a moving stretcher or ambulance), and in moderate vibration (6 m/s2) (representing vibration in helicopter transport). Any accidental bolus occurrence in extreme vibration situations (20 m/s2) was also analyzed. Simulated vibrations were reproduced by a custom-made vibration table. In the resting state without vibration and in mild vibration conditions, all pumps maintained good performance. However, in moderate vibration, flow rates in syringe pumps increased beyond their known error ranges, while flow rates in peristaltic pumps remained stable. In extreme vibration, accidental fluid bolus occurred in syringe pumps but not in peristaltic pumps. The newly developed cylinder pump maintained stable performance and was unaffected by external vibration environments.

Comparison of pre- and postoperative myocardial injuries on mortality after non-cardiac surgery: a retrospective analysis using an inverse probability weighting adjustment.

Although both pre- and postoperative myocardial injuries are strongly associated with an increased postoperative mortality, no study has directly compared the effects of pre- and postoperative myocardial injuries on 30-day mortality after non-cardiac surgery. Therefore, we evaluated and compared the effects of pre- and postoperative myocardial injury on 30-day mortality after non-cardiac surgery. From January 2010 to December 2016, patients undergoing non-cardiac surgery were stratified into either the normal (n = 3182), preoperative myocardial injury (n = 694), or postoperative myocardial injury (n = 756) groups according to the peak cardiac troponin value. Myocardial injury was defined as a sole elevation of cardiac troponin value above the 99th percentile upper reference limit without ischemic symptom using the 4th universal definition of myocardial infarction. Patients in the preoperative myocardial injury group were further divided into the attenuated (n = 177) or persistent myocardial injury group (n = 517) according to the normalization of cardiac troponin level in postoperative period. As the primary outcome, postoperative 30-day mortalities were compared among the groups using the weighted Cox proportional-hazards regression models with the inverse probability weighting. Compared with the normal group, postoperative 30-day mortality was increased significantly both in the pre- and postoperative myocardial injury groups (1.4% vs. 10.7%; hazard ratio [HR] 3.12; 95% confidence interval [CI] 1.62-6.01; p = 0.001 and 1.4% vs. 7.4%; HR 4.49; 95% CI 2.34-8.60; p < 0.001, respectively), however, there was no difference between the pre- and postoperative myocardial injury groups (HR, 1.44; 95% CI 0.79-2.64; p = 0.45). In addition, the attenuated myocardial injury group showed a significantly lower postoperative 30-day mortality than the persistent myocardial injury group (5.6% vs. 12.4%; HR 2.23; 95% CI 1.17-4.44; p = 0.02). In patients undergoing non-cardiac surgery, preoperative myocardial injury also increased postoperative 30-day mortality to a similar degree of postoperative myocardial injury. Further studies on the importance of preoperative myocardial injury are needed.Clinical trial number and registry URL: KCT0004348 ( www.cris.nih.go.kr ).

Analgesic Efficacy of Preemptive Transversus Abdominis Plane Block in Patients Undergoing Laparoscopic Colorectal Cancer Surgery.

Despite rapid advancements in laparoscopic surgical devices and techniques, pain remains a significant issue. We examined the efficacy of preemptive transversus abdominis plane (TAP) block for acute postoperative pain in patients undergoing laparoscopic colorectal cancer surgery. We retrospectively analyzed 153 patients who underwent laparoscopic colorectal cancer surgery with or without TAP block; among them, 142 were allocated to the TAP or non-TAP group. We performed between-group comparisons of demographic, clinical, and anesthetic data and pain scores at a postoperative anesthesia care unit (PACU) and at postoperative days 1, 3, and 5. There were no significant between-group differences in demographic and clinical characteristics. The mean arterial pressure, heart rate, and minimum alveolar concentration (MAC) were significantly lower in the TAP group at the start and end of surgery. The post-extubation bispectral index was significantly higher in the TAP group. There were no significant between-group differences in the pain scores and opioid consumption at the PACU or at postoperative days 1, 3, and 5, or in the time to pass flatus, the hospital stay length, and postoperative complications. Preemptive TAP block showed an intraoperative, but not postoperative, analgesic effect, characterized by a low mean arterial pressure, heart rate, and MAC.

Clinically-defined preoperative serum phosphorus abnormalities and outcomes of coronary artery bypass grafting: Retrospective analysis using inverse probability weighting adjustment.

BACKGROUND: Serum phosphorus is a well-known marker of vascular calcification, but the effects of serum phosphorus abnormalities defined by clinical criteria on the outcomes of coronary artery bypass grafting (CABG) remain unclear. We aimed to evaluate whether preoperative serum phosphorus abnormalities defined based on clinical criteria are associated with outcomes of CABG using a relatively new statistical technique, inverse probability weighting (IPW) adjustment. METHODS: From January 2001 to December 2014, 4,989 consecutive patients who underwent CABG were stratified into normal (2.5-4.5 mg/dl; n = 4,544), hypophosphatemia (<2.5 mg/dl; n = 238), or hyperphophatemia (>4.5 mg/dl; n = 207) groups depending on preoperative serum phosphorus level. RESULTS: The primary outcome was all-cause death during a median follow-up of 48 months. Secondary outcomes were cardiovascular death, graft failure, myocardial infarction, repeat revascularization, and stroke. In multivariate Cox analysis, preoperative hypophosphatemia was significantly associated with all-cause death (hazard ratio [HR] 1.76; 95% confidence interval [CI] 1.13-2.76; P = 0.01). However, this association varied depending on chronic kidney disease and emergent operation (p for interaction = 0.05 and 0.03, respectively). In addition, analysis after IPW adjustment demonstrated that preoperative serum phosphorus abnormalities were not significantly associated with all-cause death (P = 0.08) or any secondary outcomes except graft failure. Graft failure was significantly associated with preoperative hypophosphatemia (HR 2.51; 95% CI 1.37-4.61; P = 0.003). CONCLUSION: Our study showed that preoperative serum phosphorus abnormalities in clinical criteria were not associated with outcomes after CABG except for graft failure. And, the association of hypophosphatemia with graft failure remains to be evaluated.

Comparison of Operator Workloads Associated with the Single-unit Anyfusion® Pump and the Changeover from a Syringe Pump to an Infusion Pump.

BACKGROUND: A changeover from a syringe pump to an infusion pump may transiently interrupt drug administration and result in medication errors. A newly developed infusion device (Anyfusion®) that combines the functions of an infusion pump and a syringe pump in a single unit was recently commercialized. This study compared the operator workloads associated with the Anyfusion® pump and with the conventional method using two infusion devices (a syringe pump and an infusion pump). METHODS: This was a prospective, randomized, crossover-designed simulation study using an imitation arm with an intravascular line. We compared the two methods in terms of total execution time, total number of button clicks, and subjective difficulty using a numerical rating scale with a score from 0 (extremely easy) to 10 (extremely difficult). RESULTS: Twenty-two nurses successfully performed both interventions according to the allocated sequence. Total execution times did not differ between the two methods (129.5 ± 23.2 seconds for the conventional method vs. 121.2 ± 24.3 seconds for the Anyfusion® method; P = 0.244), although the total number of clicks was significantly fewer using the Anyfusion® than the conventional method (median [interquartile range]: 10.0 [9.0-12.0] vs. 21.0 [20.0-25.0], respectively; P < 0.001). Participants rated the Anyfusion® method as easier than the conventional method (1.7 ± 1.2 vs. 3.6 ± 1.6; P < 0.001, respectively). CONCLUSION: The introduction of Anyfusion® lessened the workload of practitioners required by the changeover process, which might reduce the risk of medication errors and subsequent patient harm. TRIAL REGISTRATION: Clinical Research Information Service Identifier: KCT0004172.

Utility of stroke volume variation measured using non-invasive bioreactance as a predictor of fluid responsiveness in the prone position.

The aim of this prospective study was to evaluate the usefulness of stroke volume variation (SVV) derived from NICOM® to predict fluid responsiveness in the prone position. Forty adult patients undergoing spinal surgery in the prone position were included in this study. We measured SVV from NICOM® (SVVNICOM) and FloTrac™/Vigileo™ systems (SVVVigileo), and pulse pressure variation (PPV) using automatic (PPVauto) and manual (PPVmanual) calculations at four time points including supine and prone positions, and before and after fluid loading of 6 ml kg-1 colloid solution. Fluid responsiveness was defined as an increase in the cardiac index from Vigileo™ of ≥12 %. There were 19 responders and 21 non-responders. Prone positioning induced a significant decrease in SVVNICOM, SVVVigileo, PPVauto, and PPVmanual. However, all of these parameters successfully predicted fluid responsiveness in the prone position with area under the receiver-operator characteristic curves for SVVNICOM, SVVVigileo, PPVauto, and PPVmanual of 0.78 [95 % confidence interval (CI) 0.62-0.90, P = 0.0001], 0.79 (95 % CI 0.63-0.90, P = 0.0001), 0.76 (95 % CI 0.6-0.88, P = 0.0006), and 0.84 (95 % CI 0.69-0.94, P < 0.0001), respectively. The optimal cut-off values were 12 % for SVVNICOM, SVVVigileo, and PPVauto, and 10 % for PPVmanual. SVV from NICOM® successfully predicts fluid responsiveness during surgery in the prone position. This totally non-invasive technique for assessing individual functional intravenous volume status would be useful in a wide range of surgeries performed in the prone position.

Does the Type of Anesthetic Technique Affect In-Hospital and One-Year Outcomes after Off-Pump Coronary Arterial Bypass Surgery?

Despite numerous previous studies, there is little data on the effects of anesthetics on clinical outcome after off-pump coronary arterial bypass grafting (OPCAB). Therefore, we retrospectively compared the effects of anesthetic choice on in-hospital major adverse events (MAEs) and one-year major adverse cardiovascular and cerebral events (MACCEs) in patients undergoing OPCAB. Electronic medical records were reviewed in 192 patients who received propofol-remifenanil total intravenous anesthesia (TIVA) and propensity score-matched 662 patients who received isoflurane anesthesia. The primary endpoints were in-hospital MAEs and one-year MACCEs. The components of in-hospital MAEs were in-hospital death, myocardial infarction (MI), coronary revascularization, stroke, renal failure, prolonged mechanical ventilation longer than 72 h, and postoperative new cardiac arrhythmia requiring treatment. One-year MACCEs was defined as a composite of all-cause mortality, MI, coronary revascularization, and stroke. There was no significant difference in risk of in-hospital MAEs (OR = 1.29, 95% CI = 0.88-1.88, P = 0.20) or one-year MACCEs (OR = 0.81; 95% CI = 0.46-1.42, P = 0.46) between the groups. The risk of postoperative new arrhythmia including new atrial fibrillation significantly increased in the TIVA group compared to the isoflurane anesthesia group (OR = 1.72, 95% CI = 1.12-2.63, P = 0.01). In conclusion, the choice between propofol-remifentanil TIVA and isoflurane anesthesia did not show differences in incidence of in-hospital MAEs or one-year MACCEs in patients undergoing OPCAB. However, further studies on the effects of anesthetics on development of in-hospital new arrhythmia will be needed.