Bolus Dose Research Articles

Calculation of Effective Dose of Phenylephrine Bolus for Treatment of Post–Spinal Hypotension in Preeclamptic Patients Undergoing Caesarean Section—A Nonrandomized Controlled Trial

Calculation of Effective Dose of Phenylephrine Bolus for Treatment of Post–Spinal Hypotension in Preeclamptic Patients Undergoing Caesarean Section—A Nonrandomized Controlled Trial

Plasma volume is associated with micronutrient mass but not concentration in healthy US women of reproductive age

BackgroundPlasma transports nutrients and composes more than half of the volume of blood. A few prior studies suggest that plasma volume fluctuations may impact certain micronutrient concentrations. We hypothesized a slight negative correlation between plasma volume and micronutrient biomarkers throughout the menstrual cycle in healthy women of reproductive age (n = 45). MethodsThe study involved three visits during one menstrual cycle where fasting blood samples were taken to measure biomarker concentrations for zinc, copper, magnesium, manganese, iron, ferritin, retinol, and hemoglobin. A bolus dose of indocyanine green (ICG; equivalent to 0.25 mg.kg-1 of body weight) was injected to measure plasma volume. The total circulating micronutrient biomarker mass was calculated using the plasma volume and biomarker concentration. We used Spearman's correlation and fractional polynomial regression techniques to assess the relationship between plasma volume and biomarker concentration and mass. ResultsPlasma volume ranged from 1210 to 3520 mL. During all three visits, the correlation between micronutrient biomarker concentrations and plasma volume ranged from -0.05 to 0.10 (all P > 0.05); However, there was a strong positive correlation between biomarker mass and plasma volume, ranging from 0.26 to 0.95 (all P < 0.05). Five of the eight biomarkers examined (zinc, copper, magnesium, retinol, and hemoglobin) showed a correlation coefficient > 0.70 (P < 0.001) between mass and plasma volume. ConclusionOur findings indicate that biomarker concentrations are maintained across a range of plasma volume, suggesting that plasma volume may not be necessary to interpret micronutrient status in healthy non-pregnant women of reproductive age.

The influence of sex on the dosage of remimazolam co-administered with remifentanil for loss of consciousness in adult patients: an up-and-down sequential allocation trial

BackgroundThis study aimed to determine the 50% effective dose of remimazolam co-administered with remifentanil for loss of consciousness in men and women as well as to investigate whether there are between-sex differences.MethodsUsing a modified Dixon’s up-and-down allocation approach, we sequentially enrolled male and female patients aged 19–60 years with American Society of Anesthesiologists class I or II who were scheduled for robotic surgery. For both sexes, the starting remimazolam dose was 0.15 mg/kg, with a step size of 0.05 mg/kg. After achievement of a target effect-site concentration 2.0 ng/ml of remifentanil, and administration of a bolus dose of remimazolam, we assessed whether adequate loss of consciousness (defined as a Modified Observer’s Assessment of Alertness/Sedation scale score < 2 within 2 min) was achieved.ResultsWe included 22 male and 22 female patients. Based on Dixon’s up-and-down method, the 50% effective dose of remimazolam (mean ± standard error) was 0.13 ± 0.01 mg/kg and 0.17 ± 0.01 mg/kg in the male and female groups, respectively (P = 0.34). Isotonic regression analysis revealed that the 95% effective dose (95% confidence interval) was 0.19 (0.18–0.20) mg/kg in the male group and 0.29 (0.29–0.30) mg/kg in the female group.ConclusionsThere was no between-sex difference in the 50% effective dose of remimazolam for loss of consciousness; however, the 95% effective dose was significantly higher in female patients than in male patients.Trial registrationThis study protocol was registered at Clinical Research Information Service (CRIS No. KCT0007951, 02/12/2022).

The Hemodynamic Effects of Bolus Dose Calcium in Patients Undergoing Pulmonary Artery Reconstruction and Unifocalization Surgery: A Pilot Study

Objectives: To determine if bolus administration of calcium increases pulmonary artery pressures after unifocalization procedures or pulmonary artery reconstruction surgery. Design: Retrospective cohort study using Stanford University's data warehouse. Setting: A large pediatric heart center within an academic quaternary care facility. Participants: All patients undergoing pulmonary artery reconstruction or unifocalization procedure identifiable within the data warehouse. Interventions: We collected data from Stanford University's data repository; we formatted it and analyzed it using RStudio (v 2023.06.1+524). Measurements and Main Results: Our primary outcome is the change in pulmonary artery systolic pressure (PASP) after a bolus administration of calcium. Secondary endpoints include changes in pulmonary arterial to systemic arterial pressure ratio, mean arterial pressure, right sided filling pressure, and left atrial pressure. We used the Friedman test to assess differences and the Durbin-Conover rank-sum for pairwise comparisons. We found a difference in PASP after a bolus dose of calcium (Friedman X2 = 13.67, p = 0.003), with a higher PASP five minutes after calcium administration when compared to two minutes before the administration (35 mmHg versus 33 mmHg, p = 0.01), and a higher PASP 10 minutes after calcium administration when compared to two minutes before the administration (35 mmHg versus 33 mmHg, p = 0.008). Conclusions: Calcium bolus administration led to an increase in pulmonary arterial pressure in patients after pulmonary artery reconstruction or unifocalization surgeries. It may be prudent to avoid bolus administration in this patient population immediately after repair or in patients with right ventricular dysfunction.

A pilot study of the proarrhythmic effects of pimobendan injection in clinically healthy cats.

Pimobendan is not currently approved for use in cats, although its usefulness in feline hypertrophic cardiomyopathy has been suggested. Reports indicate an increase in arrhythmic events following oral administration to healthy cats. Given the greater potency of intravenous administration compared to oral intake, it is conceivable that the incidence of arrhythmias may be increased following pimobendan injection. Therefore, this study aimed to investigate the proarrhythmic effects of pimobendan injection in cats. Five clinically healthy cats underwent physical examination, echocardiography, blood pressure measurements, and 24-hour Holter electrocardiography immediately before and after receiving pimobendan as an intravenous bolus dose of 0.15mg/kg twice daily for 3 days. Additionally, a 24-hour Holter electrocardiography recording was conducted on the third day of pimobendan or placebo IV administration to assess heart rate, arrhythmias, and heart rate variability. Following pimobendan administration, there was a significant increase in total 24-hour heart rate. Echocardiography revealed a significant increase in mitral valve annulus systolic velocity (S') on the ventricular septal wall side, indicative of enhanced contractility. Only one cat exhibited paroxysmal ventricular tachycardia and an increase in the frequency of arrhythmic events. Conversely, in the remaining cats, a decreasing trend in the number of arrhythmias was observed. These findings indicate that intravenous administration of pimobendan may not be implicated in the onset of arrhythmias. Nevertheless, further research is warranted to explore the effects of intravenous pimobendan administration in cats with myocardial disease.

Anticoagulation methods used and role of antithrombin III level monitoring in children on continuous renal replacement therapy: an observational cross-sectional study

BackgroundIn critically ill cases, CRRT is a renal replacement intervention. The most common reason why CRRT terminates prematurely (non-electively) is clotting in the extracorporeal circuit, more especially in the filter.Aim of workTo determine the frequency of thrombotic and hemorrhage complications throughout CRRT, the role of antithrombin III level monitoring, the type of anticoagulation, and the dose and laboratory tests utilized to monitor it.MethodThe study was carried out on 58 children who were undergoing CRRT. The children underwent a comprehensive history-taking, assessment, CRRT prescription parameters and alterations, vascular access data, anticoagulation type, dose, and adjustment, as well as monitoring of antithrombin III levels. Furthermore, any extracorporeal circuit clotting or bleeding was documented.ResultsOf the 58 sessions that were examined, 25 (43.1%) resulted in filter clotting. The indication was cured in 16 cases (27.6%), 8 cases (13.8%) resulted in the patient’s mortality, and 9 cases (15.5%) had life-threatening bleeding. The remaining 33 cases (56.9%) were not terminated with filter clotting. Forty-one (70.7%) of studied sessions used unfractionated heparin as anticoagulation, 22.4% used heparin-protamine, 5.2% was not anticoagulated, and one circuit (1.7%) was anticoagulated using regional citrate.Filter clotting incidence was significantly related to activated partial thromboplastin time (a PTT) value at the end of sessions (P value = 0.000), and platelets count after 4 h of session initiation (P value = 0.048). Antithrombin III levels pre-heparin infusion less than 80 were found in patients who received higher doses of a heparin bolus dose, median dose 35 (IQR 20–35), this relation is statistically significant (P value = 0.042).ConclusionIn the 58 cases that were examined, the incidence of bleeding was 32.8%; however, 19% of the cases were not severe. The incidence of filter clotting was 43.1% in the study group. a PTT value at the end of sessions, and platelets count after 4 h could be predictors of thrombotic complications during CRRT, antithrombin III deficiency before sessions is a predictor of filter clotting.

Intrapleural Fibrinolytic Interventions for Retained Hemothoraces in Rabbits.

Bleeding within the pleural space may result in persistent clot formation called retained hemothorax (RH). RH is prone to organization, which compromises effective drainage, leading to lung restriction and dyspnea. Intrapleural fibrinolytic therapy is used to clear the persistent organizing clot in lieu of surgery, but fibrinolysin selection, delivery strategies, and dosing have yet to be identified. We used a recently established rabbit model of RH to test whether intrapleural delivery of single-chain urokinase (scuPA) can most effectively clear RH. scuPA, or single-chain tissue plasminogen activator (sctPA), was delivered via thoracostomy tube on day 7 as either one or two doses 8 h apart. Pleural clot dissolution was assessed using transthoracic ultrasonography, chest computed tomography, two-dimensional and clot displacement measurements, and gross analysis. Two doses of scuPA (1 mg/kg) were more effective than a bolus dose of 2 mg/kg in resolving RH and facilitating drainage of pleural fluids (PF). Red blood cell counts in the PF of scuPA, or sctPA-treated rabbits were comparable, and no gross intrapleural hemorrhage was observed. Both fibrinolysins were equally effective in clearing clots and promoting pleural drainage. Biomarkers of inflammation and organization were likewise comparable in PF from both groups. The findings suggest that single-agent therapy may be effective in clearing RH; however, the clinical advantage of intrapleural scuPA remains to be established by future clinical trials.

Feasibility of a single-phase portal venous CT protocol using bolus tracking technique and lean body weight-based contrast media dose.

To evaluate the impact of the use of lean body weight (LBW)-based contrast material (CM) dose and bolus tracking technique on portal venous phase abdominal CT image quality. IRB-approved prospective study; informed consent was acquired. In the period July-November 2023, we randomly selected 105 oncologic patients scheduled for a portal venous phase abdominal CT to undergo our experimental protocol (i.e., 0.7 gI/Kg of LBW CM administration and bolus tracking on the liver). Included patients had performed a "standard" portal venous phase abdominal CT (i.e., 0.6 gI/Kg of total body weight (TBW) contrast material administration and 70 s fixed delay) on the same scanner within the previous 12 months. One reader evaluated CT images measuring liver, portal vein, kidney cortex, and spleen attenuation; values were normalized to paraspinal muscles. Median administered contrast dose (350 mgI/mL CM) was 99 mL (IQR: 81-115 mL) using the experimental protocol and 110 mL (IQR: 100-120 mL) using the standard one (p < 0.0001). Median acquisition delay using the experimental protocol was 65" (IQR 59-73"). Median normalized hepatic enhancement was significantly higher using the experimental protocol (1.97, IQR: 1.83-2.47 vs. 1.86, IQR: 1.58-2.11; p < 0.0001). Median normalized portal vein enhancement was significantly higher using the experimental protocol (3.43, IQR: 2.73-4.04 vs. 2.91, IQR: 2.58-3.41; p < 0.0001). No statistically significant differences were found in the kidneys' cortex and aorta normalized enhancement (p > 0.05). The combination of LBW-based CM dose administration and bolus tracking allows a significant CM dose reduction and a significant liver and portal vein enhancement increase. Lean body weight-based contrast material (CM) dose administration and bolus tracking technique in portal venous phase CT scans overcome differences in body composition and hemodynamics, improving reproducibility. It allows a significant CM dose reduction with increased liver and portal vein enhancement. Lean body weight (LBW)-based contrast material (CM) dosing could be superior to total body weight dosing. Portal venous phase CT with a liver bolus tracking technique improved liver and spleen enhancement with a reduced contrast dose. The combination of LBW-based CM dosing and liver bolus tracking technique enables more "customized" CT examinations.

Combined nefopam-fentanyl use in PCA for postoperative analgesia in spinal surgery patients: a randomized, controlled, single-blind trial

Background &amp; objective: The use of fentanyl to manage postoperative pain in spinal surgery patients is common, although there have been concerns about potential of drug abuse and dependence. We investigated the effects of the combined administration of nefopam and fentanyl through intravenous (IV) patient-controlled analgesia (PCA) on early postoperative pain and possible side effects in patients undergoing spinal surgeries. Methodology: In this randomized, controlled study, 70 patients were allocated to receive either fentanyl 10 µg/mL (Group F) or fentanyl 10 µg/mL with nefopam 1.2 mg/mL (Group FN), with a total PCA volume of 100 mL per infusion bag. Patients received a background dose of 0.25 µg/kg/h and bolus dose of 0.5 mL SOS (fentanyl 5 µg). The lockout interval was set at 10 min and upper limit was set at 15 mL/4 h. The PCA parameters were set according to the body weight of each patient. Results: The cumulative postoperative fentanyl consumptions after 48 h for Group F and Group NF were reported as 744.6 ± 94.2 µg and 631 ± 62.5 µg (P &lt; 0.05) respectively. The average number of bolus doses requested by the patients in Group F and FN were 20.8 ± 11.0, and NF 11.4± 7.6). The A/D ratio of both groups for the bolus doses were 70%. Group NF consistently scored a lower VAS and VAS-D score during the 48-hour postoperative period. However, the VAS scores significantly differ statistically between groups at 1, 6, 9, and 12 hours. Within group differences, the VAS score differed significantly statistically during the 0-1, 1-2, and 2-3 hours for Group F, while 24-36 hours for Group NF. Conclusion: The inclusion of nefopam in patient-controlled analgesia for spine surgery patients significantly reduced total use of fentanyl within the 48 hours postoperatively after the surgery. Patients receiving fentanyl with nefopam consistently had lower VAS scores at different time points. Abbreviations: PCA - patient-controlled analgesia; VAS - Visual Analogue Scale Keywords: postoperative pain, fentanyl, nefopam, patient-controlled analgesia Citation: Le XD, Nguyen ML, Nguyen DT, Do TH, Nguyen HG. Combined nefopam-fentanyl use in PCA for postoperative analgesia in spinal surgery patients: a randomized, controlled, single-blind trial. Anaesth. pain intensive care 2024;28(4):687−691; DOI: 10.35975/apic.v28i4.2370 Received: January 06, 2024; Reviewed: April 14, 2024; Accepted: April 14, 2024

Haemodynamic Responses Following Lidocaine Infusion on Hypertensive Patient Undergoing Laparoscopic Cholecystectomy

Many pharmacological methods have been evaluated to attenuate the adverse haemodynamic responses resulting from airway manipulation and pneumoperitoneum. Intravenous lidocaine infusion is one of them; bolus dose of intravenous lidocaine is used to reduce haemodynamic changes resulting from intubation and extubation reflex whereas intraoperative infusion of lidocaine has been used for post-operative analgesia in laparoscopic cholecystectomy. This randomized controlled trial was conducted to observe the effectiveness of lidocaine infusion in obtundation of haemodynamic responses on hypertensive patient undergoing laparoscopic cholecystectomy. A total number of 80 patients were enrolled in this study. Patients were allocated into two groups by computer generated random chart according to a 1:1 ratio. The patients of group A were given general anaesthesia with placebo normal saline infusion and the patients of group B were given general anaesthesia with lidocaine infusion (1.5mg/kg). Mean differences of blood pressure (SBP &amp; MAP) and heart rate at different time periods from baseline were compared between two groups. The demographic profiles were almost similar between the groups (p&gt;0.05). In comparison between two groups, heart rate, systolic blood pressure and mean arterial pressure rise from baseline value was more in normal saline group (group A) than lidocaine test group (group B) during peri-intubation, pneumoperitoneum and peri-extubation period. Statistical difference was significant between two groups (p&lt;0.05) in different haemodynamic parameters. Adverse events such as tachycardia premature ventricular contraction (PVC) and hypertension were observed much more in group A, which was higher than that of group B. We observed that administration of lidocaine infusion attenuates haemodynamic responses of hypertensive patient during laparoscopic cholecystectomy. CBMJ 2024 July: vol. 13 no. 02 P: 148-157

A Randomised Clinical Trial to Compare the Efficacy and Safety of Dexmedetomidine-Ropivacaine Versus Fentanyl-Ropivacaine for Epidural Labour Analgesia.

Background An epidural block is a superior potent approach to labour analgesia, and ropivacaine combined with fentanyl has been successfully practised for it. Dexmedetomidine, as a novel form of labour analgesia, must be researched further. Our study results give insight into the epidural block and come up with a pioneering approach for labour analgesia. Methodology A total of 68 parturients were assigned to two equal groups and received either dexmedetomidine with ropivacaine (Group RD) or fentanylwith ropivacaine (Group RF). Parturients received a loading dose and maintenance was given using a patient-controlled analgesia (PCA) pump. Analgesia onset time, labour duration, rescue dose requirement, and Visual Analogue Scale (VAS) pain scores were noted. Appearance, Pulse, Grimace, Activity and Respiration (APGAR) scores of newborns, Ramsay Sedation Scale (RSS) scores of mothers, and maternal side effects were observed. Results Group RDshowed a shorter onset time of analgesia (group RD: 12.50 ± 1.31 minutes vs. group RF: 15.26 ± 1.46 min), less local anaesthetics requirement (group RD: 47.54 ±5.37 ml vs. group RF: 59.05 ± 6.62 ml), less number of bolus doses (group RD: 0.15 ± 0.36 vs. group RF: 1.21 ± 0.95), and shorter duration from the epidural administration to the delivery (group RD: 312.97 ± 42.40 minutes vs. group RF: 345.94 ±14.67 minutes) than group RF. VAS values of the RD group were significantly less than the RF group. The RSS scores were comparably low in both groups, and excessive sedation was not seen in any group. Newborn APGAR values were comparably on the higher side in the two groups. Adverse effects were observed in the two groups, like hypotension, nausea/vomiting, bradycardia, shivering, and pruritus, which were insignificant. Conclusion The RD group showed an improved analgesic effect with a quicker onset of action,reduced requirement of local anaesthetics, and lower VAS scores compared to the RF group. With ropivacaine, dexmedetomidine shows more efficacy than fentanyl during epidural block and is a safe alternative for labour pain management.

Efficacy and Safety of Terlipressin Infusion in Hepatorenal Syndrome-Acute Kidney Injury (HRS-AKI): A Retrospective Observational Study.

Background Hepatorenal syndrome-acute kidney injury (HRS-AKI) is an event that occurs in chronic liver disease (CLD) and is associated with high morbidity and mortality. Terlipressin, a vasopressin analog, is used for the treatment of portal hypertension-related gastrointestinal (GI) bleeding and is found to be effective in the management of HRS-AKI. Continuous infusion of terlipressin maintains a high mean arterial pressure while reducing adverse events. It is better tolerated and equally effective at lower doses than intravenous boluses in patients with HRS-AKI. Aim of the study This study aimed to evaluate the safety and efficacy of terlipressin infusion at the rate of 4 mg/day in the treatment of HRS-AKI. Methods This retrospective study included patients who had HRS-AKI according to the modified International Club of Ascites (ICA) definition. Patients were started on a continuous intravenous infusion. The included patients received terlipressin 1 mg stat followed by a 4 mg infusion over 24 hours, and the infusion was continued until specific response criteria were met or for a maximum of seven days. Results In total, 136 patients were included in this study. The mean age of the study group was 45 years, the mean Child-Turcotte-Pugh (CTP) score was 11, the mean model for end-stage liver disease (MELD) score was 30, and the mean serum creatinine was 2.46 mg/dl. A response to treatment in the form of reduction of serum creatinine was observed in 94 (69.1%) patients, 30 (22%) patients showed no response, and worsening of creatinine was seen in 12 (8.8%) patients. The mean duration of hospital stay was 7.6 days, the mean serum creatinine was 1.17 mg/dl at the end of treatment, and the mean CTP and MELD scores in treatment responders were nine and 27, respectively. A total of 29 (21.3%) of 136 patients had adverse events during the terlipressin infusion therapy. Conclusion Terlipressin infusion has sustained effects on splanchnic hemodynamics with fewer and less severe adverse events than intravenous bolus doses. Terlipressin infusion at a dose of 4 mg/day appeared to be well tolerated, with similar outcomes to that of 2 mg/day with a significantly lower albumin dose. These findings emphasize the importance of optimizing treatment protocols, particularly those favoring infusion methods, to enhance efficacy and minimize adverse effects.

Magnesium sulfate for fetal neuroprotection in preterm pregnancy: a meta-analysis of randomized controlled trials

BackgroundIntravenous administration of magnesium sulfate (MgSO4) to expectant individuals before childbirth, has been evaluated to reduce the likelihood of mortality and occurrence cerebral palsy in their offspring. Therefore, this systematic review and meta-analysis conducted to determine if were the prophylactic use of magnesium sulfate in women at risk for preterm delivery leads to decrease in the incidence of death or cerebral palsy.MethodsA comprehensive search of electronic databases was done to identify relevant studies. Selection of eligible studies was based on predetermined inclusion criteria. Data extraction was performed, and the methodological quality of the selected studies was assessed using appropriate evaluative tools. A meta-analysis was carried out to estimate the overall effect of intravenous administration of magnesium sulfate on the incidence of death or cerebral palsy.ResultsA total of 7 studies met the inclusion criteria and were included in the final analysis. No significant publication bias was observed. The risk of fetal neurological impairment was significantly lower in the MgSO4 group compared to the control group relative risk (RR = 0.70, 95% CI: 0.56 to 0.87; I20%). However, neonatal mortality was not significantly associated with MgSO4 injection. (RR = 1.03, 95% CI: 0.88 to 1.21; I2 = 42%). Subgroup analysis was done based on the bolus dosage of MgSO4 and the duration of the trial follow-up. revealing a non-significant differences between-group.ConclusionThis study demonstrated that MgSO4 administration can improve fetal neurological impairment and cerebral palsy but is not linked to reducing mortality. Further studies are necessary to strengthen the evidence and clarify the underlying mechanisms.

Optimizing patient-controlled analgesia: a narrative review based on a single center audit process.

Intravenous patient-controlled analgesia (PCA) is valuable for delivering opioids in a flexible and timely manner. Although it is designed to offer personalized analgesia driven by the patients themselves, users often report insufficient pain relief, which can be addressed by optimizing its settings and multimodal analgesia. We adopted a systematic approach to modify PCA protocols by utilizing a serial audit process based on institutional PCA data. This review retrospectively examined the process, encompassing data from 13,230 patients who had used PCA devices. The two modifications to the fentanyl-based PCA protocols resulted in three distinct phases. In the first phase, high opioid consumption and unintended PCA withdrawal were the common issues. These were addressed in the second phase by omitting the routine use of basal infusion. However, this led to increased delivery-to-demand ratios, mitigated in the third phase by increasing the bolus dose from 15 μg to 20 μg. These serial protocol changes have produced varied outcomes across different surgical departments, underscoring the need for careful and gradual adjustments and thorough impact assessments. Drawing insights from this audit process, we incorporated findings from the literature on PCA settings and multimodal analgesic approaches. This review underscores the significance of iterative feedback and refinement of analgesic protocols to achieve optimal postoperative pain management. Additionally, it discusses critical considerations regarding the postoperative audit processes.

The effect of intravenous magnesium sulphate infusion on total intravenous anesthesia with propofol in adult dogs: A randomized, blinded trial

ObjectiveTo evaluate cardiopulmonary, arterial blood gas and propofol-sparing effects of magnesium sulfate (MgSO4) constant rate infusion (CRI) in mechanically ventilated dogs maintained under total intravenous anesthesia with propofol. Study designBlinded, randomized, clinical trial. AnimalsA total of 24 healthy adult dogs. MethodsDogs were premedicated with intramuscular acepromazine (0.05 mg kg–1) and morphine (0.5 mg kg–1), followed by an intravenous (IV) bolus of saline or MgSO4 (50 mg kg–1 over 15 minutes) and propofol (given to effect to induce anesthesia). Anesthesia was maintained with an IV propofol infusion (beginning at 0.3 mg kg–1 minute–1, adjusted as necessary). Concurrently, one of three IV infusions were administered: GS (0.9% NaCl), GM30 (MgSO4, 30 mg kg–1 hour–1) or GM80 (MgSO4, 80 mg kg–1 hour–1). Propofol induction and maintenance doses were recorded. The following variables were recorded at baseline (T0), after bolus treatment (T1), after beginning mechanical ventilation (T5) and every 15 minutes until the end of the procedure (T15–T120): mean arterial pressure, heart rate, peripheral oxygen saturation, end-tidal partial pressure of CO2, temperature, blood gas variables, indirect calorimetry and extubation time. Values of p < 0.05 were considered significant. ResultsPropofol induction bolus dose was lower in GM30 (31.2%, p = 0.04) and GM80 (38.9%, p = 0.003) than in GS. The maintenance propofol infusion rate in GM80 was 16.9% lower (p = 0.03), resulting in fewer propofol CRI rescues during the perioperative period. GM30 and GM80 exhibited faster extubation times than GS (46.2%, p = 0.002 and 48.9%, p = 0.001, respectively). Conclusions and clinical relevanceInfusion of a 50 mg kg–1 bolus, followed by CRI of MgSO4 (30 and 80 mg kg–1 hour–1), reduces the propofol induction and maintenance (CRI) requirement, maintaining cardiorespiratory stability and reducing the time required to extubation.

Intravenous initial bolus during prophylactic norepinephrine infusion to prevent spinal hypotension for cesarean delivery: A randomized controlled, dose-finding trial

BackgroundPrevious studies have shown that a 0.05 μg/kg/min of norepinephrine infusion in combination with an initial bolus reduces the incidence of spinal hypotension during cesarean delivery. The initial norepinephrine bolus influences the incidence of spinal hypotension during continuous norepinephrine infusion; however, the ideal initial bolus dose for 0.05 μg/kg/min of continuous infusion remains unknown. MethodsThis randomized, controlled, dose-finding study randomly allocated 120 parturients scheduled for elective cesarean delivery to receive initial bolus doses of 0, 0.05, 0.10, and 0.15 μg/kg of norepinephrine, followed by continuous infusion at a rate of 0.05 μg/kg/min. The primary outcome was the dose-response relationship of the initial norepinephrine bolus in preventing the incidence of spinal hypotension. Spinal hypotension was defined as systolic blood pressure (SBP) decreased to <80% of the baseline value or to an absolute value of <90 mmHg from intrathecal injection to delivery, and severe spinal hypotension was defined as SBP decreased to <60% of the baseline value. The secondary outcomes included the incidence of nausea and/or vomiting, hypertension, and bradycardia, as well as the Apgar scores and results of the umbilical arterial blood gas analysis. The effective dose (ED) 90 and ED95 were estimated using probit regression. ResultsThe per-protocol analysis included 117 patients. The incidence of spinal hypotension varied significantly among the groups: Group 0 (51.7%), Group 0.05 (44.8%), Group 0.10 (23.3%), and Group 0.15 (6.9%). The ED90 and ED95 values were 0.150 μg/kg (95% confidence interval [CI], 0.114–0.241 μg/kg) and 0.187 μg/kg (95% CI, 0.141–0.313 μg/kg), respectively. However, the ED95 value fell outside the dose range examined in this study. The incidence of severe spinal hypotension differed significantly (P = 0.02) among Groups 0 (17.2%), 0.05 (10.3%), 0.10 (3.3%), and 0.15 (0.0%); however, the incidence of hypertension and bradycardia did not. The incidence of nausea and/or vomiting decreased with an increase in the initial bolus dose (P = 0.03). The fetal outcomes were comparable among the groups. ConclusionsAn initial bolus of 0.150 μg/kg of norepinephrine may be the optimal dose for preventing spinal hypotension during cesarean delivery with a continuous infusion rate of 0.05 μg/kg/min, and does not significantly increase the incidence of hypertension but substantially reduces the risk of nausea and/or vomiting.

Population pharmacokinetic modeling of sufentanil in adult Korean patients undergoing cardiopulmonary bypass surgery.

Sufentanil is frequently used as an anesthetic agent in cardiac surgery owing to its cardiovascular safety and favorable pharmacokinetics. However, the pharmacokinetics profiles of sufentanil in patients undergoing cardiopulmonary bypass (CPB) surgery remain less understood, which is crucial for achieving the desired level of anesthesia and mitigating surgical complications. Therefore, this study aimed to develop a population pharmacokinetic model of sufentanil in patients undergoing CPB surgery and elucidate the clinical factors affecting its pharmacokinetic profile. Adult patients who underwent cardiac surgery with CPB and were administered sufentanil for anesthesia were enrolled. Arterial blood samples were collected to quantify plasma concentrations of sufentanil and clinical laboratory parameters, including inflammatory cytokines. A population pharmacokinetic model was established using nonlinear mixed-effects modeling. Simulations were performed using the pharmacokinetic parameters of the final model. Overall, 20 patients were included in the final analysis. Sufentanil pharmacokinetics were modeled using a two-compartment model, accounting for CPB effects. Sufentanil clearance increased 2.80-fold during CPB and warming phases, while the central compartment volume increased 2.74-fold during CPB. CPB was a significant covariate affecting drug clearance and distribution volume. No other significant covariates were identified despite increased levels of the inflammatory cytokines, including IL-6, IL-8, and TNF-α during CPB. The simulation indicated a 30 μg loading dose and 40 μg/h maintenance infusion for target-controlled infusion. Additionally, a bolus dose of 60 μg was added at CPB initiation to adjust for exposure changes during this phase. Considering the target sufentanil concentrations, a uniform dosing regimen was acceptable for effective analgesia.

A physiologically-based pharmacokinetic modeling approach for dosing amiodarone in children on ECMO.

Extracorporeal membrane oxygenation (ECMO) is a cardiopulmonary bypass device commonly used to treat cardiac arrest in children. The American Heart Association guidelines for cardiopulmonary resuscitation (CPR) and emergency cardiovascular care recommend using amiodarone as a first-line agent to treat ventricular arrhythmias in children with cardiac arrest. However, there are no dosing recommendations for amiodarone to treat ventricular arrhythmias in pediatric patients on ECMO. Amiodarone has a high propensity for adsorption to the ECMO components due to its physicochemical properties leading to altered pharmacokinetics (PK) in ECMO patients. The change in amiodarone PK due to interaction with ECMO components may result in a difference in optimal dosing in patients on ECMO when compared with non-ECMO patients. To address this clinical knowledge gap, a physiologically-based pharmacokinetic model of amiodarone was developed in adults and scaled to children, followed by the addition of an ECMO compartment. The pediatric model included ontogeny functions of cytochrome P450 (CYP450) enzyme maturation across various age groups. The ECMO compartment was parameterized using the adsorption data of amiodarone obtained from exvivo studies. Model predictions captured observed concentrations of amiodarone in pediatric patients with ECMO well with an average fold error between 0.5 and 2. Model simulations support an amiodarone intravenous (i.v) bolus dose of 22 mg/kg (neonates), 13 mg/kg (infants), 8 mg/kg (children), and 6 mg/kg (adolescents). This PBPK modeling approach can be applied to explore the dosing of other drugs used in children on ECMO.

Advancements in Insulin Pumps: A Comprehensive Exploration of Insulin Pump Systems, Technologies, and Future Directions.

Insulin pumps have transformed the way diabetes is managed by providing a more accurate and individualized method of delivering insulin, in contrast to conventional injection routines. This research explores the progression of insulin pumps, following their advancement from initial ideas to advanced contemporary systems. The report proceeds to categorize insulin pumps according to their delivery systems, specifically differentiating between conventional, patch, and implantable pumps. Every category is thoroughly examined, emphasizing its unique characteristics and capabilities. A comparative examination of commercially available pumps is provided to enhance informed decision making. This section provides a thorough analysis of important specifications among various brands and models. Considered factors include basal rate and bolus dosage capabilities, reservoir size, user interface, and compatibility with other diabetes care tools, such as continuous glucose monitoring (CGM) devices and so on. This review seeks to empower healthcare professionals and patients with the essential information to improve diabetes treatment via individualized pump therapy options. It provides a complete assessment of the development, categorization, and full specification comparisons of insulin pumps.

The Ventilatory Changes of Pediatric Peroral Endoscopic Myotomy Patients.

Peroral endoscopic myotomy (POEM) has proven to be a successful treatment method for achalasia in both adult and pediatric patients. Yet, there is a lack of evidence for anaesthetic management of pediatric patients who underwent POEM procedure. In this study, we aim to present perioperative and postoperative management strategies for pediatric patients with achalasia from in anaesthesia aspect. Medical records were reviewed for 16 pediatric patients at a single center who underwent POEM procedure for achalasia between 2017 and 2020. Patients' data regarding demographics, preoperative diet, body mass index, perioperative monitoring and vitals, airway management, anaesthesia maintenance, mechanical ventilation settings duration of recovery, length of stay, pain management and adverse events were evaluated. The study cohort included 7 female and 9 male patients with a mean age of 5.5 years. Anaesthesia maintenance was provided with 0.8-1.2 minimum alveolar concentration sevoflurane in a 40-60% O2-air mixture, Remifentanil infusion and bolus doses of Rocuronium. The median age was 3 years for patients ventilated in pressure controlled ventilation mode and 10 years in volume controlled ventilation mode. Respiration rate and minute ventilation were adjusted to maintain end tidal carbon dioxide (ETCO2) below 45 mmHg. Needle decompression was applied for 14 patients (87.5%) for treatment of capnoperitoneum. The mean procedure duration and recovery room duration were 66 (±22.9) minutes and 62 (±21) minutes, respectively. Postoperative pain management is provided with paracetamol and tramadol in total 8 patients (50%). There was no adverse event during postoperative period and all patients discharged in a mean time of 3 days. POEM has demonstrated encouraging outcomes in terms of safety and effectiveness in pediatric patients. Due to challenging nature of the pediatric patients, it is important to acknowledge that the procedure requires specialized anaesthesia management. Management of perioperative complications of increased ETCO2 requires understanding the physiologic results of pneumo-mediastinum and pneumo-peritoneum. Beside the known anaesthetic management strategies, a tailored approach should be adopted for each patient. Further investigations should be conducted to develop standardized management.