Increased packed cell volume alters point of care viscoelastic clotting parameters in horses.

BACKGROUND: Polycythaemia and coagulopathy are identified risk factors for non-survival in critically ill horses. Assessment of coagulation is recommended for critical care monitoring but may be affected by concurrent polycythaemia. OBJECTIVE: To evaluate the effects of induced polycythaemia on coagulation parameters as measured by a point-of-care viscoelastic coagulation device (VCM Vet™). STUDY DESIGN: Prospective interventional study. METHODS: Healthy adult horses (n = 7) were given 6 mcg/kg of phenylephrine IV over 15 min to induce transient polycythaemia. Samples for packed cell volume (PCV), total solids (TS), complete blood count (CBC), activated partial thromboplastin time (PTT), prothrombin (PT) and VCM Vet™ viscoelastic testing were collected at baseline (T0), 5 min (T1) and 2 h (T2) post-phenylephrine infusion. Splenic volume was measured by transabdominal ultrasonography. VCM Vet™ and plasma-based coagulation parameters, splenic volume and haematologic values were compared within and between time points. RESULTS: Splenic volume decreased from T0 (11.5 ± 4.8 L) to T1 (6.1 ± 2 L, p = 0.04) and returned to baseline volume by T2 (12.1 ± 3.9 L, p = 0.8), consistent with phenylephrine-induced splenic contraction. PCV increased from T0 (37% ± 4%) to T1 (56.3% ± 5.3%; p < 0.001) and returned to baseline at T2 (41.6% ± 3.6%; p = 0.1). A10 and A20 (amplitude at 10 and 20 min, VCM units) were decreased from T0 (12.6 ± 1.6, 18.9 ± 5) to T1 (5.4 ± 1.9, 7.6 ± 2.4; both p < 0.001) and remained lower than baseline at T2 (9.3 ± 2.1, 12.7 ± 3; both p = 0.01). PT and PTT remained within reference ranges with no significant difference over time (p = 0.5 and 0.09, respectively). PCV was negatively correlated with CFT (R = -0.61, p = 0.003), A10 (R = -0.9, p < 0.001) and A20 (R = -0.87, p < 0.001). MAIN LIMITATIONS: Small sample size, limited to healthy mares. CONCLUSIONS: Phenylephrine-induced polycythaemia was associated with hypocoagulable viscoelastic traces using the VCM Vet™ device without effect on plasma-based coagulation assessments or platelet number. Further investigation of viscoelastic testing is needed in horses with increased PCV due to clinical illness.

Interaction of simultaneous hypoxia and baroreflex loading on control of sympathetic action potential subpopulations.

Efferent muscle sympathetic nerve activity (MSNA) is under tonic baroreflex control. The arterial baroreflex exerts the strongest influence over medium-sized sympathetic action potential (AP) subpopulations in efferent MSNA recordings. Prior work from multi-unit MSNA recordings has shown baroreflex loading selectively abolishes the sympathetic response to hypoxia. The purpose of the study was to examine baroreflex control over different-sized AP clusters and characterize the neural recruitment strategies of sympathetic AP subpopulations with baroreflex and combined baroreflex/chemoreflex (i.e., hypoxia) activation. We loaded the arterial baroreceptors (intravenous phenylephrine) alone and in combination with systemic hypoxia (SpO2 80%) in 9 healthy young men. We extracted sympathetic APs using wavelet-based methodology and quantified baroreflex gain for individual AP clusters. AP baroreflex threshold gain was measured as the slope of the linear relationship between AP probability versus diastolic blood pressure for 10 normalized clusters. Baroreflex loading with phenylephrine decreased MSNA and AP firing compared to baseline (all P < 0.05). However, the phenylephrine-mediated decrease in AP firing was lost with concurrent hypoxia (P = 0.384). Compared with baseline, baroreflex loading reduced medium sized AP cluster baroreflex threshold slope (condition P = 0.005) and discharge probability (condition P < 0.0001); these reductions from baseline were maintained during simultaneous hypoxia (both P < 0.05). Present findings indicate a key modulatory role of the baroreceptors on medium-sized APs in blood pressure regulation that withstands competing signals from peripheral chemoreflex activation.

Endothelial α1-adrenergic receptor activation improves cardiac function in septic mice via PKC-ERK/p38MAPK signaling pathway.

Cardiomyopathy is particularly common in septic patients. Our previous studies have shown that activation of the alpha 1 adrenergic receptor (α1-AR) on cardiomyocytes inhibits sepsis-induced myocardial dysfunction. However, the role of cardiac endothelial α1-AR in septic cardiomyopathy has not been determined. Here, we identified α1-AR expression in mouse and human endothelial cells and showed that activation of α1-AR with phenylephrine (PE) improved cardiac function and survival by preventing cardiac endothelial injury in septic mice. Mechanistically, activating α1-AR with PE decreased the expression of ICAM-1, VCAM-1, iNOS, E-selectin, and p-p38MAPK, while promoting PKC and ERK1/2 phosphorylation in LPS-treated endothelial cells. These effects were abolished by a PKC inhibitor or α1-AR antagonist. PE also reduced p65 nuclear translocation, but this suppression is not blocked by PKC inhibition. Treatment with U0126 (a specific ERK1/2 inhibitor) reversed the effects of PE on p38MAPK phosphorylation. Our results demonstrate that cardiac endothelial α1-AR activation prevents sepsis-induced myocardial dysfunction in mice by inhibiting the endothelial injury via PKC-ERK/p38MAPK signaling pathway and a PKC-independent inhibition of p65 nuclear translocation. These findings offer a new perspective for septic patients with cardiac dysfunction by inhibiting cardiac endothelial cell injury through α1-AR activation.

A Comparison of Norepinephrine versus Phenylephrine to Prevent Hypotension after Spinal Anesthesia for Cesarean Section: Systematic Review and Meta-Analysis.

BACKGROUND: This systematic review and meta-analysis aimed to compare the effects of using phenylephrine or norepinephrine on the pH and base excess (BE) of the umbilical artery and vein in parturients undergoing cesarean section. METHODS: The study protocol was registered in INPLASY. Independent researchers searched Ovid-Medline, Ovid-EMBASE, and Cochrane Central Register of Controlled Trials (CENTRAL) databases and Google Scholar for relevant randomized controlled trials (RCTs). The primary outcome of this study was the umbilical artery (UA) or umbilical vein (UV) pH as neonatal condition at birth, and the secondary outcome was the UA or UV BE as an additional prognostic value over the measurement of umbilical pH. RESULTS: There was no evidence of a difference between phenylephrine and norepinephrine for overall, UA, and UV pH (mean difference (MD) -0.001, 95% confidence interval (CI) -0.004 to 0.007; MD 0.000, 95%CI -0.004 to 0.004; and MD 0.002, 95%CI -0.013 to 0.017). There was also no evidence of a difference between phenylephrine and norepinephrine for overall, UA, and UV BE (MD 0.096, 95% CI -0.258 to 0.451; MD 0.076, 95%CI -0.141 to 0.294; and MD 0.121, 95%CI; -0.569 to 0.811). A meta-regression showed that factors such as umbilical artery or vein, infusion method, single or twin, and the number of parturients per study had no effect on the UA pH, UV pH, UA BE, or UV BE. No evidence of publication bias was detected. CONCLUSIONS: There was no evidence of a difference between phenylephrine and norepinephrine for umbilical pH and BE. A subgroup analysis and meta-regression also did not show evidence of differences.

Efficacy and Safety of Perioperative Angiotensin II Versus Phenylephrine as a First-Line Continuous Infusion Vasopressor in Kidney Transplant Recipients.

INTRODUCTION: Angiotensin II (ATII) maintains blood pressure via RAAS with a beneficial adverse effect profile versus catecholamines and phenylephrine. Head-to-head data comparing ATII to phenylephrine are lacking regarding renal allograft function, hemodynamic efficacy, and safety within the perioperative period of kidney transplantation. METHODS: This single-center, retrospective study included adult kidney transplant recipients who received continuous infusions of ATII or phenylephrine within a 24-h perioperative period as a first-line vasopressor according to an institutional algorithm. The primary endpoint was allograft function. Secondary endpoints were hemodynamic efficacy and adverse effects. RESULTS: Among 105 patients, there was no significant difference in IGF (p = 0.545), SGF (p = 0.557), or DGF (p = 0.878) between patient cohorts. In the 34 patients with cold ischemia time (CIT) > 14-h, IGF was higher (p = 0.013) and DGF (p = 0.045) was lower in the ATII cohort versus phenylephrine. In all patients, ATII was associated with a decreased need for additional vasopressor agents (p < 0.001). Adverse effect profiles were similar between cohorts (p > 0.05). CONCLUSION: Among kidney transplant recipients, ATII may be a suitable first-line alternative compared with phenylephrine in the perioperative period for hypotension management with a reduced need for additional vasopressor support. Allograft benefits were observed in patients with prolonged CIT.

Effect of norepinephrine and phenylephrine on prothrombotic response in patients undergoing cesarean section under spinal anesthesia: protocol for a randomized, double-blind, controlled study.

BACKGROUND: Norepinephrine and phenylephrine are commonly used vasoactive drugs to treat hypotension during the perioperative period. The increased release of endogenous norepinephrine elicits prothrombotic changes, while parturients are generally in a hypercoagulable state. Therefore, this trial aims to investigate whether there is a disparity between equivalent doses of prophylactic norepinephrine infusion and phenylephrine infusion on prothrombotic response in patients undergoing cesarean section under spinal anesthesia. METHODS: Sixty-six eligible parturients will be recruited for this trial and randomly assigned to the norepinephrine or phenylephrine group. The "study drug" will be administered at a rate of 15 ml/h starting from the intrathecal injection. The primary outcome are plasma coagulation factor VIII activity (FVIII: C), fibrinogen, and D-dimer levels. The secondary outcomes include hemodynamic variables and umbilical artery blood pH value. DISCUSSION: Our study is the first trial comparing the effect of norepinephrine and phenylephrine on prothrombotic response in patients undergoing cesarean section under spinal anesthesia. Positive or negative results will all help us better understand the impact of vasoactive drugs on patients. If there are any differences, this trial will provide new evidence for maternal choice of vasoactive medications in the perioperative period. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR2300077164. Registered on 1 November 2023. https://www.chictr.org.cn/ .

Determination of ED90s of Phenylephrine and Norepinephrine Infusion for Prevention of Spinal Anesthesia-Induced Hypotension in Patients with Preeclampsia During Cesarean Delivery.

Background: Vasopressors remain an important strategy for managing spinal anesthesia-induced hypotension in women with preeclampsia. The aim of this study was to investigate the ED90s and efficacy ratio of phenylephrine and norepinephrine in managing spinal anesthesia-induced hypotension in women with preeclampsia during cesarean delivery. Methods: 60 women with preeclampsia, who underwent cesarean delivery, were randomly assigned to receive either a continuous intravenous infusion of phenylephrine or norepinephrine following spinal anesthesia. The initial dosage of phenylephrine or norepinephrine for the first women was 0.5 or 0.05 µg/kg/min, respectively, and subsequent infusion dosages were adjusted based on their efficacy in preventing spinal anesthesia-induced hypotension (defined as a systolic blood pressure less than 80% of the baseline level). The incremental or decremental doses of phenylephrine or norepinephrine were set at 0.1 or 0.01 µg/kg/min. The primary outcomes were the ED90s and efficacy ratio of phenylephrine and norepinephrine infusions for preventing spinal anesthesia-induced hypotension prior to delivery. Results: The results obtained from isotonic regression analysis revealed that the ED90 values of the phenylephrine and norepinephrine group for preventing spinal anesthesia-induced hypotension were 0.597 (95% CI: 0.582-0.628) and 0.054 (95% CI: 0.053-0.056) µg/kg/min, respectively, with an efficacy ratio of 11.1:1. The results of Probit regression analysis revealed that the ED90 values were determined to be 0.665 (95% CI: 0.576-1.226) and 0.055 (95% CI: 0.047-0.109) µg/kg/min, respectively, with an efficacy ratio of 12.1:1. Conclusion: The administration of 0.6 µg/kg/min phenylephrine and 0.05 µg/kg/min norepinephrine has been found to effectively manage a 90% incidence of spinal anesthesia-induced hypotension in women with preeclampsia.

Comparison of Prophylactic Phenylephrine Infusion and Rescue Bolus Administration for Maintaining Blood Pressure During Spinal Anaesthesia for Caesarean Delivery in Obese Parturient: A Randomised Control Trial.

Background: Phenylephrine (PE) is one of the vasopressor used to treat hypotension during anaesthesia. The primary aim of this study was to compare the effect of prophylactic infusion and rescue bolus of PE on the haemodynamic changes during spinal anaesthesia (SA) for Caesarean section (CS) in obese parturients. Methods: A total of 74 obese parturients scheduled for elective CS under SA were randomised into two groups; Group A (n = 37) received prophylactic PE infusion starting at 50 µg min-1 and adjusted according to the given algorithm and Group B (n = 37) received 100 µg PE bolus to treat hypotension. The measured parameters were systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), the total requirement of PE and neonatal Apgar score. Results: Six patients were excluded from the analysis due to missing data and only 68 were analysed. Group A showed significantly higher SBP, DBP and MAP than Group B (P < 0.05). The requirement of PE was higher in Group A than Group B [817.7 (265.7) µg versus 360.6 (156.0) µg; P = < 0.05]. Both groups had no difference in terms of the neonatal Apgar score. Conclusion: Prophylactic PE infusion provided better haemodynamic control than therapeutic boluses in obese parturients undergoing CS under SA.

Dropless Cataract Surgery: The Effect of Intracameral Phenylephrine/Ketorolac Infusion as a Single Agent on Postoperative Outcomes.

Objective The objective of this study was to assess the feasibility of using an intracameral phenylephrine/ketorolac infusion during cataract surgery as a single agent to prevent postoperative pain, inflammation, and other complications. Methods A prospective, single-group feasibility study was conducted in which phenylephrine/ketorolac infusion was administered during cataract surgery and no perioperative topical drops were initially prescribed. Patients underwent optical coherence tomography, corrected distance visual acuity testing, and slit lamp biomicroscopy examination at perioperative visits, during which they also reported symptoms of pain, irritation, and/or photophobia. A goal adverse event (AE) rate was set at ≤5.0%. Results A total of 94 eyes (60 patients) were included in this study. The AE rate was 13.8% (13/94 eyes) with pain/irritation in eight eyes, cystoid macular edema (CME) in three eyes, and corneal edema in three eyes. Conclusions Based on an AE rate goal of ≤5.0%, using intraoperative, intracameral phenylephrine/ketorolac alone was not deemed a feasible alternative to current postoperative eye drop regimens in our clinical setting. However, a 13.8% AE rate is comparable to the rates of postoperative CME, corneal edema, pain, and irritation in the published literature. Thus, more research is needed to truly define this approach as inferior or non-inferior to the current standard of care.

A retrospective study of the effects of a vasopressor bolus on systolic slope (dP/dt) and dynamic arterial elastance (Eadyn).

BACKGROUND: To enhance the utility of functional hemodynamic monitoring, the variables systolic slope (dP/dt) and dynamic arterial elastance (Eadyn) are calculated by the Hypotension Prediction Index (HPI) Acumen® Software. This study was designed to characterize the effects of phenylephrine and ephedrine on dP/dt and Eadyn. METHODS: This was a retrospective, non-randomized analysis of data collected during two clinical studies. All patients required intra-operative controlled mechanical ventilation and had an indwelling radial artery catheter connected to an Acumen IQ sensor. Raw arterial pressure waveform data was downloaded from the patient monitor and all hemodynamic measurements were calculated off-line. The anesthetic record was reviewed for bolus administrations of either phenylephrine or ephedrine. Cardiovascular variables prior to drug administration were compared to those following vasopressor administrations. The primary outcome was the difference for dP/dt and Eadyn at baseline compared with the average after the bolus administration. All data sets demonstrated non-normal distributions so statistical analysis of paired and unpaired data followed the Wilcoxon matched pairs signed-rank test or Mann-Whitney U test, respectively. RESULTS: 201 doses of phenylephrine and 100 doses of ephedrine were analyzed. All data sets are reported as median [95% CI]. Mean arterial pressure (MAP) increased from 62 [54,68] to 78 [76,80] mmHg following phenylephrine and from 59 [55,62] to 80 [77,83] mmHg following ephedrine. Stroke volume and cardiac output both increased. Stroke volume variation and pulse pressure variation decreased. Both drugs produced significant increases in dP/dt, from 571 [531, 645] to 767 [733, 811] mmHg/sec for phenylephrine and from 537 [509, 596] to 848 [779, 930] mmHg/sec for ephedrine. No significant changes in Eadyn were observed. CONCLUSION: Bolus administration of phenylephrine or ephedrine increases dP/dt but does not change Eadyn. dP/dt demonstrates potential for predicting the inotropic response to phenylephrine or ephedrine, providing guidance for the most efficacious vasopressor when treating hypotension. TRIAL REGISTRATION: Data was collected from two protocols. The first was deemed to not require written, informed consent by the Institutional Review Board (IRB). The second was IRB-approved (Effect of Diastolic Dysfunction on Dynamic Cardiac Monitors) and registered on ClinicalTrials.gov (NCT04177225).

The effect of three different mydriatic eye drops on retinal vessel diameters.

PURPOSE: To investigate the effects of topically applied 1% tropicamide, 2.5% phenylephrine and 1% cyclopentolate on retinal vessel calliper (VC) using optical coherence tomography (OCT). METHODS: Patients who came to the ophthalmology clinic for routine examination and whose OCT films were taken before dilatation and after 30 min of last dilatation drop were included in the study. 90 ophthalmologically healthy subjects were divided into 3 groups of 30 subject each according to the application of the drops as follows: Tropicamide group (Group 1), Phenylephrine group (Group 2), Cyclopentolate group (Group 3). The right eyes of the subjects were dilated with drops and the left eyes were taken as the control group. VC of retinal artery and vein passing through an area one-half to one-disc diameter from the optic disc margin were measured from OCT films. The mean of the sum of superior retinal artery (SRA) and inferior retinal artery (IRA) VC and the mean of the sum of superior retinal vein (SRV) and inferior retinal vein (IRV) VC before and after the drop were compared. RESULTS: There was no statistically significant change in the mean sum of SRA and IRA VC and the mean sum of SRV and IRV VC before and after dilatation drops in all three groups. CONCLUSION: Dilatation drops have no statistically significant effect on retinal artery and vein VC.

Vasoconstriction with phenylephrine increases cardiac output in preload dependent patients.

General Anaesthesia (GA) is accompanied by a marked decrease in sympathetic outflow and thus loss of vasomotor control of cardiac preload. The use of vasoconstriction during GA has mainly focused on maintaining blood pressure. Phenylephrine (PE) is a pure α1-agonist without inotropic effects widely used to correct intraoperative hypotension. The potential of PE for augmenting cardiac stroke volume (SV) and -output (CO) by venous recruitment is controversial and no human studies have explored the effects of PE in preload dependent circulation using indicator dilution technique. We hypothesized that PE-infusion in patients with cardiac stroke volume limited by reduced preload would restore preload and thus augment SV and CO. 20 patients undergoing GA for gastrointestinal surgery were monitored with arterial catheter and LiDCO unity monitor. Upon stable haemodynamics after induction patients were placed in head-up tilt (HUT). All patients became preload responsive as verified by a stroke volume variation (SVV) of > 12%. PE-infusion was then started at 15-20mikrg/min and adjusted until preload was restored (SVV < 12%). Li-dilution cardiac output (CO) was initially measured after induction (baseline), again with HUT in the preload responsive phase, and finally when preload was restored with infusion of PE.At baseline SVV was 10 ± 3% (mean ± st.dev.), CI was 2,6 ± 0,4 L/min*m2, and SVI 43 ± 7mL/m2. With HUT SVV was 19 ± 4%, CI was 2,2 ± 0,4 L/min*m2, SVI 35 ± 7mL/m2. During PE-infusion SVV was reduced to 6 ± 3%, CI increased to 2,6 ± 0,5 L/min*m2, and SVI increased to 49 ± 11mL/m2. All differences p < 0,001. In conclusion: Infusion of phenylephrine during preload dependency increased venous return abolishing preload dependency as evaluated by SVV and increased cardiac stroke volume and -output as measured by indicator-dilution technique. (ClinicalTrials.gov NCT05193097).

Effect of pneumatic leg compression on phenylephrine dose for hypotension prophylaxis via variable rate infusion at cesarean delivery: an unblinded randomized controlled trial.

BACKGROUND: Phenylephrine infusion is recommended to prevent spinal hypotension during cesarean delivery (CD) but may be associated with dose-dependent side effects. We hypothesized that adding intermittent pneumatic compression (IPC) of the lower legs to a variable-rate phenylephrine infusion will reduce the dose of phenylephrine required during CD. METHODS: Seventy-six healthy women undergoing elective CD under combined spinal-epidural anesthesia were randomly assigned to IPC or control groups (n = 38 per group). After spinal anesthesia, IPC of the lower legs was initiated in the IPC group, and all women received a phenylephrine infusion starting at 25 µg·min-1 and increasing by 16.7 µg·min-1 for systolic blood pressure (SAP) < 90% baseline. If hypotension (SAP < 80% baseline) occurred, 100 µg phenylephrine bolus was administered. The primary outcome was the dose of phenylephrine per minute. RESULTS: The dose of phenylephrine per minute (34.4 ±â€¯7.3 µg·min-1 vs. 40.9 ±â€¯9.5 µg·min-1, P = 0.001; mean difference -6.6 µg·min-1, 95% CI -10.5 to -2.7 µg·min-1) and the incidence of hypotension (24% vs. 55%, P = 0.005) were lower in the IPC group than in the control group. There were no significant differences between the two groups in the total dose of phenylephrine (603.2 ±â€¯217.1 µg vs. 706.2 ±â€¯247.5 µg, P = 0.058; mean difference -102.9 µg, 95% CI -209.4 to 3.5 µg), maternal side effects, or neonatal outcomes. CONCLUSIONS: Intermittent pneumatic compression combined with a variable-rate phenylephrine infusion reduced the phenylephrine dose per minute and the incidence of hypotension during CD under spinal anesthesia.

Norepinephrine or phenylephrine for the prevention of post-spinal hypotension after caesarean section: A double-blinded, randomized, controlled study of fetal heart rate and fetal cardiac output.

STUDY OBJECTIVE: Spinal anesthesia often causes hypotension, with consequent risk to the fetus. The use of vasopressor agents has been highly recommended for the prevention of spinal anesthesia-induced hypotension during caesarean delivery. Many studies have shown that norepinephrine can provide more stable maternal hemodynamics than phenylephrine. We therefore tested the hypothesis that norepinephrine preserves fetal circulation better than phenylephrine when used to treat maternal hypotension consequent to spinal anesthesia. DESIGN: Prospective, randomized, double-blinded study. SETTING: Operating room. PATIENTS: We recruited 223 parturients with uncomplicated singleton pregnancies who were scheduled for elective caesarean section under combined spinal-epidural anesthesia. INTERVENTIONS: The patients received prophylactic intravenous infusion of either 0.08 µg/kg/min norepinephrine or 0.5 µg/kg/min phenylephrine for prevention of spinal anesthesia-induced hypotension. MEASUREMENTS: Changes in fetal heart rate and fetal cardiac output before and after spinal anesthesia were measured using noninvasive Doppler ultrasound. MAIN RESULTS: 90 subjects who received norepinephrine infusion and 93 subjects who received phenylephrine infusion were ultimately analyzed in the present study. The effects of norepinephrine and phenylephrine on the change of fetal heart rate and fetal cardiac output at 3 and 6 min after spinal block were similar. Although there was a statistically significant decrease in fetal cardiac output at 6 min after subarachnoid block initiation in both the norepinephrine group (mean difference 0.02 L/min; 95% CI, 0-0.04 L/min; P = 0.03) and the phenylephrine group (mean difference 0.02 L/min; 95% CI, 0-0.04 L/min; P = 0.02), it remained within the normal range. CONCLUSIONS: Prophylactic infusion of comparable doses of phenylephrine or norepinephrine has similar effects on fetal heart rate and cardiac output changes after spinal anesthesia. Neither phenylephrine nor norepinephrine has meaningful detrimental effects on fetal circulation or neonatal outcomes.

Optimizing anesthesia strategies to NSCLC patients in VATS procedures: Insights from drug requirements and patient recovery patterns.

Understanding the intricate relationship between cancer clinicopathological features and anesthetics dosage is crucial for optimizing patient outcomes and safety during surgery. This retrospective study investigates this relationship in patients with non-small cell lung cancer (NSCLC) undergoing video-assisted thoracic surgery (VATS). A comprehensive analysis of medical records was undertaken for NSCLC patients who underwent VATS with intravenous compound inhalation general anesthesia. Patients were categorized based on histological, chemotherapy, radiotherapy, and epidural anesthesia factors. Statistical analysis was performed to compare the differences between the groups. The results revealed compelling insights. Specifically, patients with lung adenocarcinoma (LUAD) undergoing VATS exhibited higher dosages of rocuronium bromide and midazolam during general anesthesia, coupled with a shorter post-anesthesia care unit (PACU) stay compared to those with squamous cell carcinoma (sqCL). Furthermore, chemotherapy patients undergoing VATS demonstrated diminished requirements for phenylephrine and remifentanil in contrast to their non-chemotherapy counterparts. Similarly, radiotherapy patients undergoing VATS demonstrated a decreased necessity for rocuronium bromide compared to non-radiotherapy patients. Notably, patients who received epidural anesthesia in combination with general anesthesia manifested reduced hydromorphone requirements and prolonged hospital stays compared to those subjected to general anesthesia alone. In conclusion, the findings from this study indicate several important observations in diverse patient groups undergoing VATS. The higher dosages of rocuronium bromide and midazolam in LUAD patients point to potential differences in drug requirements among varying lung cancer types. Additionally, the observed shorter PACU stay in LUAD patients suggests a potentially expedited recovery process. The reduced anesthetic requirements of phenylephrine and remifentanilin chemotherapy patients indicate distinct responses to anesthesia and pain management. Radiotherapy patients requiring lower doses of rocuronium bromide imply a potential impact of prior radiotherapy on muscle relaxation. Finally, the combination of epidural anesthesia with general anesthesia resulted in reduced hydromorphone requirements and longer hospital stays, suggesting the potential benefits of this combined approach in terms of pain management and postoperative recovery. These findings highlight the importance of tailoring anesthesia strategies for specific patient populations to optimize outcomes in VATS procedures.

Epinephrine vs. phenylephrine infusion for prophylaxis against maternal hypotension after spinal anesthesia for cesarean delivery: a randomized controlled trial.

BACKGROUND: The hemodynamic effects of relatively low-dose epinephrine and phenylephrine infusions during cesarean delivery under spinal anesthesia were compared. METHODS: This randomized controlled trial included full-term pregnant women who underwent elective cesarean delivery. After spinal anesthesia, participants received either epinephrine (0.03 mcg/kg/min) or phenylephrine (0.4 mcg/kg/min) infusion that continued until 5 min after delivery. The primary outcome was a composite outcome of the occurrence of any of hypotension, hypertension, bradycardia, and/or tachycardia. Neonatal outcomes, including umbilical artery blood gas and Apgar scores, were assessed. RESULTS: In total, 98 patients in each group were analyzed, and the number of patients with the composite outcome was comparable between the epinephrine and phenylephrine groups (30/98 [31%] vs. 31/98 [32%], respectively; P = 0.877). However, the incidence of hypotension was likely lower in the epinephrine group than in the phenylephrine group (P = 0.066), and the number of hypotensive episodes per patient was lower in the epinephrine group than in the phenylephrine group. On the other hand, the incidence of tachycardia was higher in the epinephrine group than that in the phenylephrine group. The incidence of hypertension was comparable between the two groups and none of the participants developed bradycardia. Neonatal outcomes were comparable between the two groups. CONCLUSIONS: Epinephrine and phenylephrine infusion produced comparable maternal hemodynamics and neonatal outcomes. Epinephrine was associated with a higher incidence of maternal tachycardia and likely lower incidence of maternal hypotension than phenylephrine. IRB number: MD-245-2022. CLINICAL TRIAL REGISTRATION: This study was registered on May 31, 2023 at clinicaltrials.gov registry, NCT05881915, URL: https://classic. CLINICALTRIALS: gov/ct2/show/NCT05881915term=NCT05881915&draw=2&rank=1.

Assessing changes in regional cerebral hemodynamics in adults with a high-density full-head coverage time-resolved near-infrared spectroscopy device.

Significance: Cerebral oximeters have the potential to detect abnormal cerebral blood oxygenation to allow for early intervention. However, current commercial systems have two major limitations: (1) spatial coverage of only the frontal region, assuming that surgery-related hemodynamic effects are global and (2) susceptibility to extracerebral signal contamination inherent to continuous-wave near-infrared spectroscopy (NIRS). Aim: This work aimed to assess the feasibility of a high-density, time-resolved (tr) NIRS device (Kernel Flow) to monitor regional oxygenation changes across the cerebral cortex during surgery. Approach: The Flow system was assessed using two protocols. First, digital carotid compression was applied to healthy volunteers to cause a rapid oxygenation decrease across the ipsilateral hemisphere without affecting the contralateral side. Next, the system was used on patients undergoing shoulder surgery to provide continuous monitoring of cerebral oxygenation. In both protocols, the improved depth sensitivity of trNIRS was investigated by applying moment analysis. A dynamic wavelet filtering approach was also developed to remove observed temperature-induced signal drifts. Results: In the first protocol (28±5 years; five females, five males), hair significantly impacted regional sensitivity; however, the enhanced depth sensitivity of trNIRS was able to separate brain and scalp responses in the frontal region. Regional sensitivity was improved in the clinical study given the age-related reduction in hair density of the patients (65±15 years; 14 females, 13 males). In five patients who received phenylephrine to treat hypotension, different scalp and brain oxygenation responses were apparent, although no regional differences were observed. Conclusions: The Kernel Flow has promise as an intraoperative neuromonitoring device. Although regional sensitivity was affected by hair color and density, enhanced depth sensitivity of trNIRS was able to resolve differences in scalp and brain oxygenation responses in both protocols.

Use of vasopressors to manage spinal anesthesia-induced hypotension during cesarean delivery.

Cesarean sections are commonly performed under spinal anesthesia, which can lead to hypotension, adversely affecting maternal and fetal outcomes. Hypotension following spinal anesthesia is generally defined as a blood pressure of 80-90% below the baseline value. Various strategies have been implemented to reduce the incidence of spinal anesthesia-induced hypotension. The administration of vasopressors is a crucial method for preventing and treating hypotension. In the past decade, phenylephrine, a primarily alpha-adrenergic agonist, has been the preferred vasopressor for cesarean sections. Recently, norepinephrine, a potent alpha-agonist with modest beta-agonist activity, has gained popularity owing to its advantages over phenylephrine. Vasopressors can be administered via a bolus or continuous infusion. Although administering boluses alone is simpler in a clinical setting, continuous prophylactic infusion initiated immediately after spinal anesthesia is more effective in reducing the incidence of hypotension. Tailoring the infusion dose based on the patient's body weight and adjusting the rate in response to blood pressure changes, in addition to using a prophylactic or rescue bolus, helps reduce blood pressure variability during cesarean sections under spinal anesthesia until neonatal delivery.