Norepinephrine versus phenylephrine on cerebral tissue oxygen saturation during prophylactic infusion to prevent spinal hypotension for Caesarean birth.

BACKGROUND: Phenylephrine may cause a reduction in maternal cerebral tissue oxygen saturation (SctO2) during Caesarean birth to prevent spinal hypotension; however, the effect of norepinephrine has not been assessed. We hypothesized that norepinephrine was more effective than phenylephrine in maintaining SctO2 when preventing spinal hypotension during Caesarean birth. METHODS: We conducted a randomized, double-blind, controlled study. Sixty patients were randomly assigned to prophylactic norepinephrine or phenylephrine to maintain blood pressure during spinal anesthesia for Caesarean birth. SctO2, systolic blood pressure, and heart rate were recorded. The primary outcome was the incidence of a 10% reduction of intraoperative SctO2 from baseline or more during Caesarean birth. RESULTS: The norepinephrine group had a lower incidence of more than 10% reduction of intraoperative SctO2 from baseline than that of the phenylephrine group (13.3% vs 40.0%, P = .02). The change in SctO2 after 5 minutes of norepinephrine infusion was higher than that after phenylephrine infusion (-3.4 ±â€…4.7 vs -6.2 ±â€…5.6, P = .04). The change in SctO2 after 10 minutes of norepinephrine infusion was higher than that after phenylephrine infusion (-2.5 ±â€…4.4 vs -5.4 ±â€…4.6, P = .006). The norepinephrine group showed greater left- and right-SctO2 values than the phenylephrine group at 5 to 10 minutes. However, the change in systolic blood pressure was comparable between the 2 groups. CONCLUSION: Norepinephrine was more effective than phenylephrine in maintaining SctO2 when preventing spinal hypotension during Caesarean birth. However, the changes in clinical outcomes caused by differences in SctO2 between the 2 medications warrant further studies.

Is crystalloid co-loading necessary to prevent spinal hypotension during elective cesarean delivery? A randomized double-blind trial.

BACKGROUND: Hypotension is common during spinal anesthesia for cesarean delivery. Preventive strategies include fluid loading and phenylephrine. We hypothesized that if prophylactic phenylephrine infusion is used, omission of fluid loading would be non-inferior to fluid co-loading in maintaining cardiac output. We assumed that if there was a difference, the increase in cardiac output would be greater in the no-loading than in the co-loading group. METHODS: Term pregnant women scheduled for elective cesarean delivery were randomized to receive 1 L crystalloid co-loading or maintenance fluids only. Phenylephrine was titrated to maintain blood pressure. Changes in cardiac output following spinal anesthesia were the primary outcome. The study was powered as a non-inferiority trial, allowing the no-loading arm to have a 50% greater change in cardiac output. Heart rate, dose of phenylephrine, occurrence of nausea and vomiting, Apgar scores and neonatal acid base status were secondary outcomes. RESULTS: Data from 63 women were analyzed. In contrast to our hypothesis, there was 33% less increase in cardiac output with no loading (ratio 0.67, 95% CI 0.15 to 1.36), and 60% greater reduction of cardiac output with no loading (ratio 1.6, 95% CI 1.0 to 2.7). Total dose of phenylephrine was higher in the no-loading group. There may be a less favorable neonatal acid base status without volume loading. CONCLUSION: Omission of crystalloid co-loading leads to a decrease in cardiac output which has a potentially unfavorable impact on neonatal acid base status. We conclude that crystalloid co-loading may be useful in the presence of phenylephrine infusion.

Trends in Phenylephrine and Pseudoephedrine Sales in the US.

This study examines purchasing patterns regarding oral decongestants, concerns about their efficacy, and the need for timelier postmarket evaluation.

Comparison between remimazolam and propofol anaesthesia for interventional neuroradiology: a randomised controlled trial.

BACKGROUND: General anaesthesia can immobile patients during interventional neuroradiology to improve image quality. Remimazolam, an ultrashort-acting benzodiazepine, is advantageous for haemodynamic stability. This study compared remimazolam and propofol anaesthesia during neuroradiology procedures regarding intraoperative hypotensive events and rapid recovery. METHODS: This single-masked randomised-controlled study included 76 participants who underwent elective endovascular embolisation in a single centre. Patients were randomised between a continuous remimazolam infusion (n = 38) or a target-controlled propofol infusion group (n = 38). In the remimazolam group, flumazenil (0.2 mg) was administered at the end of the procedure. Phenylephrine was titrated to maintain the mean arterial pressure within ± 20% of the baseline value. The primary outcome was the total phenylephrine dose during the procedure. RESULTS: The total phenylephrine dose was 0.0 [0.0-30.0] µg in the remimazolam group and 30.0 [0.0-205.0] µg in the propofol group (p = 0.001). Hypotensive events were observed in 11 (28.9%) patients in the remimazolam group and 23 (60.5%) patients in the propofol group (p = 0.001). Recovery times to spontaneous breathing, eye-opening, extubation, and orientation were shorter in the remimazolam group than in the propofol group (all p < 0.001). CONCLUSIONS: Remimazolam anaesthesia showed superior haemodynamic stability compared with propofol anaesthesia during neuroradiology procedures. Systematic use of flumazenil enabled rapid recovery from remimazolam anaesthesia. REGISTRATION: University Hospital Medical Information Network Clinical Trials Registry; Registration number: UMIN000047384; URL: https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000054046.

Calculation of effective dose of phenylephrine bolus for treatment of post-spinal hypotension in pre-eclamptic patients undergoing caesarean section - a non-randomised controlled trial.

BACKGROUND: Patients with pre-eclampsia require smaller vasopressor doses compared with those with normotension for management of post-spinal hypotension during caesarean section. However, the literature has little evidence as to the phenylephrine dose required for patients with pre-eclampsia. METHODS: Fifty patients, with either pre-eclampsia or normotension, and developing post-spinal hypotension during caesarean section under spinal anaesthesia, were studied. Women in both groups did not receive prophylactic vasopressors. The first patient in each group received phenylephrine 50 µg to treat the first episode of hypotension, defined as fall of systolic blood pressure ≥20% from baseline or an absolute value <100 mmHg. If hypotension was corrected within one minute it was considered a 'success'. The doses for the subsequent patients were determined by responses to all previous patients, according to a variation of Narayana's rule for the up-down sequential allocation method. RESULTS: The 95% effective dose (ED95) and 50% effective dose (ED50) of phenylephrine was 41.7 µg (95% CI 33.8 to 49.6 µg) and 29.1 µg (95% CI 26.0 to 32.2 µg) respectively in the pre-eclampsia group, and 64.9 µg (95% CI 54.1 to 75.7 µg) and 47.3 µg (95% CI 39.7 to 54.9 µg) respectively in the normotensive group. The proportionate reduction in phenylephrine dose ranged from 33% (95% CI 18 to 44%) to 40% (95% CI 19 to 52%). CONCLUSION: Patients with pre-eclampsia may need a 33% to 40% reduction in the first phenylephrine bolus dose, compared with patients with normotension, for the treatment of the first episode of post-spinal hypotension.

Preparation/administration of push-dose versus continuous infusion epinephrine and phenylephrine: A simulation.

BACKGROUND: Hypotension is a common problem in the emergency department (ED) and intensive care unit (ICU) and can increase risk for poor outcomes. Many EDs/ICUs utilize epinephrine and phenylephrine to treat hypotension and these medications are most often administered as a continuous infusion (CI). Push-dose (PD) is the administration of small medication doses as intermittent intravenous pushes (IVPs). There is limited information comparing the time required to prepare and administer PD versus CI and errors have been reported when preparing and administering these medications at bedside. This simulation study sought to estimate preparation and administration times and preparation and errors with PD and CI epinephrine and phenylephrine when prepared by an ED/ICU pharmacist. METHODS: This crossover simulation study took place in a simulation center at an academic medical center and utilized a multi-venous intravenous training arm kit equip with an 18-gauge intravenous line, an extension tubing set, and a luer-lock adapter. The primary outcome was total preparation and administration time in seconds. The secondary outcome was major preparation and administration errors, defined as errors causing a five-fold or greater overdose. RESULTS: In total, 16 pharmacists participated, including nine ED and seven ICU pharmacists. PD had faster total preparation and administration time and administration time, but not preparation time; PD showed an approximate 70 s decrease in total preparation and administration time versus CI. PD had more major preparation and administration errors and six PD preparations (18.8%, 6/32) had at least one major preparation and administration error. CI, on the other hand, had no major preparation and administration errors. DISCUSSION: This simulation found faster total preparation and administration time with PD versus CI epinephrine and phenylephrine, but also found that PD had more major preparation and administration errors. Dilutional errors during medication preparation were the cause of 83.3% (5/6) of our overdoses. CONCLUSION: This simulation study showed that ED/ICU pharmacists had faster median total preparation and administration times for PD epinephrine and phenylephrine versus CI, but PD also had more preparation and administration errors.

Intraoperative phenylephrine infusion to reduce perioperative shivering in lower segment caesarean section: A randomised controlled study.

BACKGROUND: Shivering is described as an involuntary, repetitive activity of the skeletal muscles that can have deleterious effects on anaesthetized patients. This study aimed to evaluate the effectiveness of phenylephrine infusion in preventing perioperative shivering in patients undergoing lower segment cesarean section under spinal anesthesia and to observe the change in the patient's core temperature between the study and control groups. METHODS: A total of 118 patients scheduled for elective lower segment cesarean section under spinal anesthesia were recruited for this prospective, double-blind, randomized controlled study. The patients were randomized into 2 groups with 59 patients per group. The phenylephrine Group received phenylephrine infusion at a rate of 0.5 mcg/kg/minutes, while the Control Group received normal saline at an equivalent rate. Systolic and diastolic blood pressure, heart rate, core temperature, and the presence and intensity of shivering were recorded before induction and every 15 minutes intraoperatively and postoperatively. RESULTS: The incidence of intraoperative shivering was significantly lower in the Phenylephrine Group compared to control group (29.1% vs 47.5% respectively; P = .044). Postoperatively, the Phenylephrine Group also had a lower incidence of shivering (34.5% vs 42.4%), but the difference was not statistically significant (P value = 0.391). There were no significant differences in the intensity of shivering between the 2 groups perioperatively, as well as in the systolic and diastolic blood pressure and core temperature. The phenylephrine Group showed a significantly lower heart rate at 15, 30, and 45 minutes after spinal block (P value = .005, .000, and .008, respectively), and at 0 and 30 minutes (P value = .004 and .020 respectively) in the recovery room. There were no significant differences in perioperative adverse events such as hypotension, hypertension, and bradycardia. CONCLUSION: Phenylephrine infusion reduces the incidence of perioperative shivering in lower segment cesarean sections under spinal anesthesia.

[Possibilities of differential diagnosis of chronic diseases of the nasal cavity after surgical treatment and topical antibiotic therapy]. / Vozmozhnosti differentsial'noi diagnostiki khronicheskikh zabolevanii polosti nosa posle khirurgicheskogo lecheniya i topicheskoi antibakterial'noi terapii.

OBJECTIVE: The study was performed to assess the endoscopic state of the nasal mucosa after the use of local anti-inflammatory and antibacterial therapy, in particular, Polydexa nasal spray with phenylephrine containing Dexamethasone sodium metasulfobenzoate + Neomycin + Polymyxin B + Phenylephrine, and for the treatment of granulomatosis with polyangiitis. MATERIAL AND METHODS: The study included 940 patients who underwent examination and treatment for chronic rhinosinusitis in the clinic of otorhinolaryngology of I.P. Pavlov SPbSMU surgical treatment of the paranasal sinuses underwent 907 patients. In the postoperative period, the first group (211 patients) underwent toileting of the nasal cavity. The second group (307 patients) received irrigation therapy. The third group (389 patients) received a topical treatment combined of Polydexa with phenylephrine. The dynamics of the condition was assessed on the 1st, 3rd and 7th days of treatment, the evaluation of the effectiveness of the treatment was carried out on the 3rd and 7th days. Differential diagnosis with granulomatosis with polyangiitis was carried out in 33 patients. All patients with granulomatosis with polyangiitis showed signs of chronic rhinosinusitis. Patients were prescribed local anti-inflammatory and antibacterial therapy with Polydexa with phenylephrine for 7 days with endoscopic control of the nasal cavity. CONCLUSION: The use of the combined topical drug Polydexa with phenylephrine in patients with chronic rhinosinusitis and in patients with granulomatosis with polyangiitis has a positive effect, which reduces the clinical manifestations of chronic rhinosinusitis.

Fluid management and vasopressor use during colorectal surgery: the search for the optimal balance.

BACKGROUND: Although it is known that excessive intraoperative fluid and vasopressor agents are detrimental for anastomotic healing, optimal anesthesiology protocols for colorectal surgery are currently lacking. OBJECTIVE: To scrutinize the current hemodynamic practice and vasopressor use and their relation to colorectal anastomotic leakage. DESIGN: A secondary analysis of a previously published prospective observational study: the LekCheck study. STUDY SETTING: Adult patients undergoing a colorectal resection with the creation of a primary anastomosis. OUTCOME MEASURES: Colorectal anastomotic leakage (CAL) within 30 days postoperatively, hospital length of stay and 30-day mortality. RESULTS: Of the 1548 patients, 579 (37%) received vasopressor agents during surgery. Of these, 201 were treated with solely noradrenaline, 349 were treated with phenylephrine, and 29 received ephedrine. CAL rate significantly differed between the patients receiving vasopressor agents during surgery compared to patients without (11.8% vs 6.3%, p < 0.001). CAL was significantly higher in the group receiving phenylephrine compared to noradrenaline (14.3% vs 6%, p < 0.001). Vasopressor agents were used more often in patients treated with Goal Directed Therapy (47% vs 34.6%, p < 0.001). There was a higher mortality rate in patients with vasopressors compared to the group without (2.8% vs 0.4%, p = 0.01, OR 3.8). Mortality was higher in the noradrenaline group compared to the phenylephrine and those without vasopressors (5% vs. 0.4% and 1.7%, respectively, p < 0.001). In multivariable analysis, patients with intraoperative vasopressor agents had an increased risk to develop CAL (OR 2.1, CI 1.3-3.2, p = 0.001). CONCLUSION: The present study contributes to the evidence that intraoperative use of vasopressor agents is associated with a higher rate of CAL. This study helps to create awareness on the (necessity to) use of vasopressor agents in colorectal surgery patients in striving for successful anastomotic wound healing. Future research will be required to balance vasopressor agent dosage in view of colorectal anastomotic leakage.

Norepinephrine combined with phenylephrine versus norepinephrine in patients with septic shock: a retrospective cohort study.

BACKGROUND: Phenylephrine (PE) and norepinephrine (NE) may be used to maintain adequate blood pressure and tissue perfusion in patients with septic shock, but the effect of NE combined with PE (NE-PE) on mortality remains unclear. We hypothesized that NE-PE would not inferior to NE alone for all-cause hospital mortality in patients with septic shock. METHODS: This single-center, retrospective cohort study included adult patients with septic shock. According to the infusion type, patients were divided into the NE-PE or NE group. Multivariate logistic regression, propensity score matching and doubly robust estimation were used to analyze the differences between groups. The primary outcome was the all-cause hospital mortality rate after NE-PE or NE infusion. RESULTS: Among 1, 747 included patients, 1, 055 received NE and 692 received NE-PE. For the primary outcome, the hospital mortality rate was higher in patients who received NE-PE than in those who received NE (49.7% vs. 34.5%, p < 0.001), and NE-PE was independently associated with higher hospital mortality (odds ratio = 1.76, 95% confidence interval = 1.36-2.28, p < 0.001). Regarding secondary outcomes, patients in the NE-PE group had longer lengths of stay in ICU and hospitals. Patients in the NE-PE group also received mechanical ventilation for longer durations. CONCLUSIONS: NE combined with PE was inferior to NE alone in patients with septic shock, and it was associated with a higher hospital mortality rate.

Incidence of bradycardia during noradrenaline or phenylephrine bolus treatment of postspinal hypotension in cesarean delivery: A randomized double-blinded controlled trial.

The treatment of choice for spinal anesthesia-induced hypotension during cesarean section is phenylephrine. As this vasopressor can cause reflex bradycardia, noradrenaline is a suggested alternative. This randomized double-blinded controlled trial included 76 parturients undergoing elective cesarean delivery under spinal anesthesia. Women received noradrenaline in bolus doses of 5 mcg or phenylephrine in bolus doses of 100 mcg. These drugs were used intermittently and therapeutically to maintain systolic blood pressure ≥ 90% of its baseline value. The primary study outcome was bradycardia incidence (<60 bpm) with intermittent bolus administration of these drugs. Secondary outcomes included extreme bradycardia (<40 bpm), number of bradycardia episodes, hypertension (systolic blood pressure > 120% of baseline value), and hypotension (systolic blood pressure < 90% of baseline value and requiring vasopressor use). Neonatal outcomes per the Apgar scale and umbilical cord blood gas analysis were also compared. The incidence of bradycardia in both groups (51.4% and 70.3%, respectively; p = 0.16) were not significantly different. No neonates had umbilical vein or artery pH values below 7.20. The noradrenaline group required more boluses than phenylephrine group (8 vs. 5; p = 0.01). There was no significant intergroup difference in any of the other secondary outcomes. When administered in intermittent bolus doses for the treatment of postspinal hypotension in elective cesarean delivery, noradrenaline, and phenylephrine have a similar incidence of bradycardia. When treating hypotension related to spinal anesthesia in obstetric cases, strong vasopressors are commonly administered, thought these can also have side effects. This trial assessed bradycardia after bolus administration of noradrenaline or phenylephrine, and found no difference in risk for clinically meaningful bradycardia.

Dose-dependent Effects of PRC2 and HDAC Inhibitors on Cardiomyocyte Hypertrophy Induced by Phenylephrine.

INTRODUCTION: Postnatal cardiomyocytes respond to stress signals by hypertrophic growth and fetal gene reprogramming, which involves epigenetic remodeling mediated by histone methyltransferase polycomb repressive complex 2 (PRC2) and histone deacetylases (HDACs). However, it remains unclear to what extent these histone modifiers contribute to the development of cardiomyocyte hypertrophy. METHODS: Neonatal rat ventricular myocytes (NRVMs) were stimulated by phenylephrine (PE; 50µM) to induce hypertrophy in the presence or absence of the PRC2 inhibitor GSK126 or the HDACs inhibitor Trichostatin A (TSA). Histone methylation and acetylation were measured by Western blot. Cell size was determined by wheat germ agglutinin (WGA) staining. Cardiac hypertrophy markers were quantified by quantitative reverse transcription polymerase chain reaction (qRT-PCR). RESULTS: PE treatment induced the expression of cardiac hypertrophy markers, including natriuretic peptide A (Nppa), natriuretic peptide B (Nppb), and myosin heavy chain 7 (Myh7), in a time-dependent manner in NRVMs. Histone modifications, including H3K27me3, H3K9ac, and H3K27ac, were dynamically altered after PE treatment. Treatment with TSA and GSK126 dose-dependently repressed histone acetylation and methylation, respectively. While TSA reversed the PE-induced cell size enlargement in a wide range of concentrations, cardiomyocyte hypertrophy was only inhibited by GSK126 at a higher dose (1µM). Consistently, TSA dose-dependently suppressed the induction of Nppa, Nppb, and Myh7/Myh6 ratio, while these indexes were only inhibited by GSK126 at 1µM. However, TSA, but not GSK126, caused pro-hypertrophic expression of pathological genes at the basal level. CONCLUSION: Our data demonstrate diversified effects of TSA and GSK126 on PE-induced cardiomyocyte hypertrophy, and shed light on epigenetic reprogramming in the pathogenesis of cardiac hypertrophy.

Müller Muscle-Conjunctival Resection for Treatment of Contralateral Ptosis following Unilateral External Levator Advancement.

BACKGROUND: One of the main causes of unsatisfactory outcomes after unilateral blepharoptosis surgery is asymmetry of the upper eyelid height, which occurs as a result of a contralateral eyelid droop. Therefore, the authors evaluated the efficacy of Müller muscle-conjunctival resection (MMCR) for the treatment of contralateral ptosis following unilateral external levator advancement (ELA). METHODS: This study analyzed 26 eyelids of 26 patients with upper eyelid height asymmetry following unilateral ELA who underwent contralateral MMCR retrospectively. The phenylephrine test was performed before ELA and before MMCR. The main outcome measures were symmetry outcomes and clinical outcomes. RESULTS: The mean patient age was 55.81 ± 7.98 years (range, 44 to 70 years); 15 were female (57.7%). The Hering dependency was observed in 13 of the patients (50%) before ELA. An adequate response to phenylephrine was observed before MMCR but not before ELA. Symmetry outcomes after MMCR were perfect (<0.5 mm), good (≥0.5 mm and <1 mm), and fair (≥1 mm) in seven, 17, and two patients, respectively. An optimal upper eyelid height was noted in 47 of the 52 eyelids after the MMCR, whereas three of the 52 eyelids had minimal overcorrection, and two eyelids had undercorrection. The mean change in marginal reflex distance 1 of the contralateral eyelid droop was greater for patients with than without the Hering dependency ( P < 0.0001) after ELA but not after MMCR. Two patients (7.6%) underwent revision ELA surgery. CONCLUSION: MMCR and use of the phenylephrine test to predict the eyelid position may represent an alternative approach in patients who require management of contralateral ptosis following unilateral ELA. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Bolus Vasopressor Use for Air Medical Rapid Sequence Intubation: The Vasopressor Intravenous Push to Enhance Resuscitation Trial.

BACKGROUND: Rapid sequence intubation (RSI) may compromise perfusion because of the use of sympatholytic medications as well as subsequent positive pressure ventilation. The use of bolus vasopressor agents may reverse hypotension and prevent arrest. METHODS: This was a prospective, observational study enrolling air medical patients with critical peri-RSI hypotension (systolic blood pressure [SBP] < 90 mm Hg) to receive either arginine vasopressin (aVP), 2 U intravenously every 5 minutes, for trauma patients or phenylephrine (PE), 200 µg intravenously every 5 minutes, for nontrauma patients. The main outcome measures included an increase in SBP, a reversal of hypotension, and the occurrence of dysrhythmia or hypertension (SBP > 160 mm Hg) within 20 minutes of vasopressor administration. RESULTS: A total of 523 patients (344 aVP and 179 PE) were enrolled over 2 years. An increase in SBP was observed in 326 aVP patients (95%), with reversal of hypotension in 272 patients (79%). An increase in SBP was observed in 171 PE patients (96%), with reversal of hypotension in 148 patients (83%). A low rate of rebound hypertension was observed for both aVP and PE patients. CONCLUSION: Both aVP and PE appear to be safe and effective for treating critical hypotension in the peri-RSI period.

Evaluating an advanced double intravenous vasopressor automated system to treat hypotension during spinal anesthesia for cesarean delivery: a randomized controlled trial.

BACKGROUND: The optimal treatment of hypotension during spinal anaesthesia is uncertain. A novel double intravenous vasopressor automated (DIVA) system reduces hypotension compared to standard care, and was subsequently modified to an advanced-DIVA (ADIVA) system. The primary objective was to compare ADIVA versus DIVA on incidence of hypotension (systolic BP (SBP) < 80% baseline). METHODS: We conducted a randomized-controlled trial in women undergoing elective cesarean delivery under spinal anesthesia. SBP and heart rate were measured continuously using a Nexfin monitor. ADIVA delivered 25 µg phenylephrine (heart rate > 60 beats.min-1) or 2 mg ephedrine (heart rate < 60 beats.min-1) at SBP 90 to 110% of baseline, 50 µg phenylephrine or 4 mg ephedrine at SBP 80 to 90%, and 75 µg phenylephrine or 6 mg ephedrine at SBP < 80%. ADIVA calculated the trend of SBP; vasopressors were administered rapidly if SBP trended downward, or 30 s if SBP trended upward. In contrast, DIVA delivered 25 µg phenylephrine or 2 mg ephedrine at SBP 90 to 100% of baseline, and 50 µg phenylephrine or 4 mg ephedrine at SBP < 90%. Boluses were followed by a 10-s lockout. Other outcomes included hypertension (SBP > 120% baseline), vasopressor consumption, clinical outcomes, and performance measures from spinal anesthesia to fetal delivery. RESULTS: We analyzed 94 parturients (ADIVA: n = 46, DIVA: n = 48), with no difference in the incidence of hypotension between ADIVA (78.3%) and DIVA (83.3%, p = 0.677). ADIVA had significantly higher proportion of hypotensive SBP readings, lower phenylephrine consumption and higher umbilical arterial pH. There was no difference in hypertension, bradycardia, ephedrine consumption, intravenous fluid volume, nausea/vomiting, Apgar scores, and umbilical venous pH or lactate. ADIVA maintained SBP higher above baseline with greater fluctuation than DIVA. CONCLUSION: ADIVA was associated with a greater proportion of hypotensive SBP readings, reduced phenylephrine consumption, and increased umbilical arterial pH than DIVA. Further research is needed to determine the optimal method of vasopressor delivery in parturients undergoing cesarean delivery. TRIAL REGISTRATION: This study was registered on Clinicaltrials.gov registry (NCT03620942) on 08/08/2018.