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.

Topical Minoxidil Overdose in a Young Man With Androgenetic Alopecia: A Case Report.

Minoxidil is an effective and relatively safe topical drug that is used to treat androgenetic alopecia and other types of alopecia. This active ingredient is used in dermatology as a hair growth stimulant; however, the use of solutions containing minoxidil can be accompanied by a variety of cardiovascular systemic side effects. In this case report, we describe the case of a 23-year-old man who presented with complaints of dizziness, blurred vision, general malaise, fatigue, and feeling pre-syncopal while standing after applying large amounts of topical minoxidil solution for three days in a row. Other potential causes of the presenting condition were excluded. The symptoms quickly resolved after the discontinuation of minoxidil. No other treatment was used apart from minoxidil withdrawal.

Computer-controlled closed-loop norepinephrine infusion system for automated control of mean arterial pressure in dogs under isoflurane-induced hypotension: a feasibility study.

Introduction: Intra-operative hypotension is a common complication of surgery under general anesthesia in dogs and humans. Computer-controlled closed-loop infusion systems of norepinephrine (NE) have been developed and clinically applied for automated optimization of arterial pressure (AP) and prevention of intra-operative hypotension in humans. This study aimed to develop a simple computer-controlled closed-loop infusion system of NE for the automated control of the mean arterial pressure (MAP) in dogs with isoflurane-induced hypotension and to validate the control of MAP by the developed system. Methods: NE was administered via the cephalic vein, whereas MAP was measured invasively by placing a catheter in the dorsal pedal artery. The proportional-integral-derivative (PID) controller in the negative feedback loop of the developed system titrated the infusion rate of NE to maintain the MAP at the target value of 60 mmHg. The titration was updated every 2 s. The performance of the developed system was evaluated in six laboratory Beagle dogs under general anesthesia with isoflurane. Results: In the six dogs, when the concentration [median (interquartile range)] of inhaled isoflurane was increased from 1.5 (1.5-1.5)% to 4 (4-4)% without activating the system, the MAP was lowered from 95 (91-99) to 41 (37-42) mmHg. In contrast, when the concentration was increased from 1.5 (1.0-1.5)% to 4 (4-4.8)% for a 30-min period and the system was simultaneously activated, the MAP was temporarily lowered from 92 (89-95) to 47 (43-49) mmHg but recovered to 58 (57-58) mmHg owing to the system-controlled infusion of NE. If the acceptable target range for MAP was defined as target MAP ±5 mmHg (55 ≤ MAP ≤65 mmHg), the percentage of time wherein the MAP was maintained within the acceptable range was 96 (89-100)% in the six dogs during the second half of the 30-min period (from 15 to 30 min after system activation). The median performance error, median absolute performance error, wobble, and divergence were - 2.9 (-4.7 to 1.9)%, 2.9 (2.0-4.7)%, 1.3 (0.8-1.8)%, and - 0.24 (-0.34 to -0.11)%·min-1, respectively. No adverse events were observed during the study period, and all dogs were extubated uneventfully. Conclusion: This system was able to titrate the NE infusion rates in an accurate and stable manner to maintain the MAP within the predetermined target range in dogs with isoflurane-induced hypotension. This system can be a potential tool in daily clinical practice for the care of companion dogs.

Background factors for intra-operative hypotension during hip fracture repair surgery in the elderly under spinal anesthesia managed by orthopedic surgeons: A retrospective case-control study.

BACKGROUND: Spinal anesthesia is used for femoral trochanteric fracture surgery, but frequently induces hypotension and the causative factors remain unclear. We examined background factors for the use of an intraoperative vasopressor in elderly patients receiving spinal anesthesia for femoral trochanteric fracture surgery. METHODS: We retrospectively analyzed 203 patients >75 years (mean age, 87.9 years) with femoral trochanteric fractures who underwent short nail fixation under orthopedically managed spinal anesthesia at our hospital between April 2020 and July 2023. Patients were divided into two groups: group A (intraoperative vasopressor) and group B (no vasopressor). The following data were compared: age, sex, height, weight, body mass index, antihypertensive medication, years of experience as a primary surgeon, bupivacaine dose, puncture level, anesthesia time, operation time, hemoglobin level and blood urea nitrogen/creatinine ratio on the day of surgery, brain natriuretic peptide level, left ventricular ejection fraction, and percentage of patients operated on the day of transport. RESULTS: There were 65 patients in group A and 138 in group B. The average dose of bupivacaine was 11.7 mg. In a univariate analysis, group A was slightly younger (87.0 vs. 88.3 years), had a higher blood urea nitrogen/creatinine ratio (27.1 vs. 24.5), more frequently received ß-blockers (14.1% vs. 5.8 %) and diuretic medications (21.9% vs. 11.6 %), and had a higher puncture level. A logistic regression analysis identified younger age (p = 0.02) and diuretic medication (p = 0.001) as independent risk factors in group A. Vasopressor use was more frequent at a higher puncture level in group A (57 % for L2/3, 33 % for L3/4, 15 % for L4/5, 0 % for L5/S). CONCLUSIONS: Spinal anesthesia-induced hypotension is attributed to volume deficit or extensive sympathetic blockade and may be prevented by avoiding high puncture levels and increasing preoperative fluid supplementation in patients on diuretics. There is currently no consensus on anesthetic dosages.

Pleth variability index during preoxygenation could predict anesthesia-induced hypotension: A prospective, observational study.

STUDY OBJECTIVE: To determine whether changes in the pleth variability index (PVi) during preoxygenation with forced ventilation for 1 min could predict anesthesia-induced hypotension. DESIGN: Prospective, observational study. SETTING: A tertiary teaching hospital. PATIENTS: Ninety-six patients who underwent general anesthesia using total intravenous anesthesia were enrolled. INTERVENTIONS: Upon the patient's arrival at the preoperative waiting area, a PVi sensor was affixed to their fourth fingertip. For preoxygenation, forced ventilation of 8 breaths/min in a 1:2 inspiratory-expiratory ratio was conducted using the guidance of an audio file. One minute after preoxygenation, anesthetic administration was initiated. Blood pressure was measured for the next 15 min. MEASUREMENTS: We calculated the difference (dPVi) and percentage of change (%PVi) between the PVi values immediately before and after forced ventilation. Anesthesia-induced hypotension was defined as a mean arterial pressure of <60 mmHg within 15 min after the infusion of anesthetics. MAIN RESULTS: Overall, 87 patients were included in the final analysis. Anesthesia-induced hypotension occurred in 31 (35.6%) of the 87 patients. Receiver operating characteristic curve analyses identified a cut-off value of -2 for dPVi, with an area under the curve of 0.691 (95% confidence interval [CI], 0.564-0.818; P < 0.001) and a cut-off value of -7.6% for %PVi, with an area under the curve of 0.711 (95% CI, 0.589-0.832; P < 0.001). Further, multivariate logistic regression analysis showed that a low %PVi with an odds ratio of 9.856 (95% CI, 3.131-31.032; P < 0.001) was a significant determinant of anesthesia-induced hypotension. CONCLUSIONS: Hypotension frequently occurs during general anesthesia induction and can impact outcomes. Additionally, the percentage change in the PVi before and after preoxygenation using deep breathing can be used to predict anesthesia-induced hypotension.

Hyperandrogenism Protects Against High Blood Pressure by Nongenomic Mechanisms and Obesity Causes Hypertension in Females with Polycystic Ovary Syndrome.

BACKGROUND: Androgens induce vasorelaxation and reduce blood pressure in different mammals, including humans. Most women with polycystic ovary syndrome (PCOS), with hyperandrogenism, are obese and exhibit hypertension; thus, the fact that androgens increase blood pressure (BP) is controversial. Our aim was to determine whether hypertension is produced by androgen excess and/or obesity. METHODS: Experiments were performed in dehydroepiandrosterone; (DHEA, s.c)-induced PCOS model. BP from nonobese and obese rats with PCOS (fed a normal or high-fat diet, respectively) was evaluated weekly for 10 weeks by plethysmography and compared between them. We determined whether androgen receptors are responsible for androgen action on BP in rats with PCOS; a group of DHEA-treated rats was implanted with pellets of an antiandrogen and was compared with nonobese rats with PCOS. Isometric tension from aortas of nonobese and obese rats was recorded and compared to explore the integrity of the vascular endothelium when acetylcholine-induced endothelium-dependent vascular relaxation on phenylephrine contraction. Additionally, BP was obtained from 30 women diagnosed with PCOS: nonobese (BMI ≤25) and obese women (BMI ≥35) and compared with healthy counterparts; 15 obese and 15 nonobese women. RESULTS: Nonobese rats and women with PCOS showed hypotension, while obese rats and women with PCOS displayed hypertension. Healthy obese women were hypertensive and nonobese women remained normotensive. Antiandrogen did not modify the BP values in nonobese rats with PCOS, and obese rats with PCOS revealed marked endothelial dysfunction. CONCLUSIONS: Our findings show that obesity is responsible for hypertension in PCOS and partial endothelial damage was observed, which may contribute to elevated BP. Remarkably, hyperandrogenism is capable of regulating BP to low values that are androgen receptor-independent.

Efficacy of inferior vena cava collapsibility index and caval aorta index in predicting the incidence of hypotension after spinal anaesthesia- A prospective, blinded, observational study.

Background and Aim: Spinal anaesthesia-induced hypotension (SAIH) is a frequent side effect of spinal anaesthesia. SAIH is usually observed in patients with hypovolemia. Ultrasonography has evolved as a non-invasive tool for volume status assessment. Methods: This prospective, blinded, observational study was conducted on 75 adult patients who required spinal anaesthesia after receiving ethical approval and registering the study. Ultrasonographic evaluation of the aorta and the inferior vena cava (IVC) was done preoperatively, and the IVC collapsibility index (IVCCI) and caval aorta index were calculated. The incidence of SAIH was recorded. The strength of the association between different parameters and SAIH was calculated. To find out the value of the optimal cut-off for the prediction of SAIH, receiver operating characteristic (ROC) analysis for various ultrasound parameters was done. The bidirectional stepwise selection was utilised for multivariate analysis to choose the single best predictor. Results: SAIH was observed in 36 patients. Among demographic parameters, age, female gender, and height showed a medium correlation. Among ultrasonographic measurements, minimum IVC internal diameter (IVCmin) and IVCCI showed a strong association with SAIH. The best parameter regarding area under the ROC curve (AUC) and diagnostic accuracy was IVCCI (0.828 and 85%, respectively). On multivariate analysis, age (95% CI [1.01, 1.12], P = 0.024) and IVCCI (95% CI [1.05, 1.18], P < 0.001) were significant independent predictors. At a cut-off point of ≥43.5%, IVCCI accurately predicted SAIH (sensitivity 81% and specificity 90%). Conclusion: Preoperative ultrasonographic assessment of IVC to evaluate its collapsibility index is a convenient, cost-effective, and reproducible tool for predicting SAIH.

Trazodone Overdose Manifesting as Hypotension and QT Prolongation.

Trazodone is a medication used to treat major depressive disorder (MDD). It is in the serotonin-antagonist-and-reuptake-inhibitor class of medications with anti-cholinergic effects. Trazodone is known for its sedative effects and is hence often prescribed in those with MDD with concurrent insomnia. While few, there have been reports of patients overdosing on trazodone and developing QTc prolongation leading to fatal arrhythmias such as torsades des pointes and variable atrioventricular blocks. We present a case of a 45-year-old female with a past medical history of MDD and anxiety, who presented with dizziness, transient ataxia, and urinary incontinence following ingestion of five 100 mg trazodone tablets. Although her vitals were initially stable on admission, her EKG was concerning for QTc prolongation of 502 ms. A few hours later, she started developing hypotension and progressive QTc prolongation, with a peak of 586 ms. Given the high risk of decompensation, the patient was admitted to the ICU for further care where she received adequate supportive management in the form of fluid resuscitation, electrolyte repletion, serial EKGs every hour, and telemetry monitoring for arrhythmias, with eventual improvement in her clinical condition. Trazodone poisoning, while rare, can be fatal and hence requires close monitoring to prevent complications. Clinicians must be aware of these possible adverse outcomes when managing trazodone toxicity.

Cardiovascular and metabolic actions of the androgens: Is testosterone a Janus-faced molecule?

Cardiovascular disease (CVD) is a major cause of morbidity and mortality worldwide and in the Western world, one-third of all deaths are attributed to CVD. A conspicuous characteristic of this healthcare epidemic is that most CVD is higher in men than in age-matched premenopausal women, yet reasons for these obvious sex differences remain poorly understood. Driven by clinical case and epidemiological studies and supported by animal experiments, a strong dogma emerged early on that testosterone (TES) exerts deleterious effects on cardiovascular health and exacerbates development of CVD and metabolic dysfunctions in men. In this review, earlier and more recent clinical and experimental animal evidence of cardiovascular and metabolic effects of androgens are discussed. The more recent evidence overwhelmingly suggests that it is progressive, age-dependent declines in TES levels in men that exacerbate CVD and metabolic dysfunctions, while TES exerts beneficial systemic hypotensive effects and protects against metabolic syndrome (MetS) and type2 diabetes mellitus (T2DM). Recent findings reveal existence of bi-directional modulation of glucose and fat homeostasis by TES in females vs males, such that age-dependent declines in TES levels in males and abnormal increases in normally low TES levels in females both result in similar dysfunction in glucose and fat homeostasis, resulting in development of MetS and T2DM, central risk factors for development of CVD, in men as well as women. These findings suggest that the long-held view that TES is detrimental to male health should be discarded in favor of the view that, at least in men, TES is beneficial to cardiovascular and metabolic health.

Can Ultrasound-Guided Femoral Vein Measurements Predict Spinal Anesthesia-Induced Hypotension in Non-Obstetric Surgery? A Prospective Observational Study.

Background and objectives: To investigate whether ultrasound (US)-guided femoral vein (FV) and inferior vena cava (IVC) measurements obtained before spinal anesthesia (SA) can be utilized to predict SA-induced hypotension (SAIH) and to identify risk factors associated with SAIH in patients undergoing non-obstetric surgery under SA. Methods: This was a prospective observational study conducted between November 2021 and April 2022. The study included 95 patients over the age of 18 with an American Society of Anesthesiologists (ASA) physical status score of 1 or 2. The maximum and minimum diameters of FV and IVC were measured under US guidance before SA initiation, and the collapsibility index values of FV and IVC were calculated. Patients with and without SAIH were compared. Results: SAIH was observed in 12 patients (12.6%). Patients with and without SAIH were similar in terms of age [58 (IQR: 19-70) vs. 48 (IQR: 21-71; p = 0.081) and sex (males comprised 63.9% of the SAIH and 75.0% of the non-SAIH groups) (p = 0.533). According to univariate analysis, no significant relationship was found between SAIH and any of the FV or IVC measurements. Multiple logistic regression analysis revealed that having an ASA class of 2 was the only independent risk factor for SAIH development (p = 0.014), after adjusting for age, sex, and all other relevant parameters. Conclusions: There is not enough evidence to accept the feasibility of utilizing US-guided FV or IVC measurements to screen for SAIH development in patients undergoing non-obstetric surgery under SA. For this, multicenter studies with more participants are needed.

Effect of perioperative magnesium sulfate and labetalol infusion on peripheral perfusion and postoperative pain in nasal surgery: a randomized controlled trial.

BACKGROUND: Maintenance of adequate peripheral perfusion during controlled hypotension is necessary for patient safety and improved surgical outcomes during controlled hypotension in nasal surgery. The hypothesis of this study was to investigate the effect of perioperative magnesium sulfate and labetalol infusion on peripheral perfusion and postoperative pain in patients undergoing nasal surgery. METHODS: A total of 50 patients were randomly assigned into two equal groups in this double-blind clinical study: the magnesium sulfate group; received 40 mg/kg loading dose of intravenous (IV) magnesium sulfate followed by 10-15 mg/kg/h continuous IV infusion and the labetalol group; received 0.25 mg/kg loading dose of IV labetalol followed by 0.5-1 mg/kg/h continuous IV infusion to achieve a mean arterial blood pressure (MABP) of = 55-65 mmHg. The primary outcome was to compare the effect of perioperative magnesium sulfate and labetalol infusion on peripheral perfusion during nasal surgery. The secondary outcomes were the assessment of serum lactate, postoperative pain, time to the first call for pethidine (rescue analgesic) and total pethidine consumption. RESULTS: PPI was comparable between the groups at baseline, intubation, and 5 min. In contrast, magnesium sulfate group had a significantly higher PPI than the labetalol group. The magnesium sulfate group had a significantly higher MABP and heart rate compared to labetalol group. The time to reach the target MABP was significantly prolonged in magnesium sulfate than the labetalol group [21.6 ± 1.7 vs 6.9 ± 1.5] min. VAS scores were significantly lower for 2 hs postoperatively in the magnesium sulfate group than the labetalol group. The time to first call of pethidine was significantly prolonged in the magnesium sulfate group compared to the labetalol group [113.1 ± 5.2 vs 28.2 ± 1.5] min. CONCLUSIONS: Magnesium sulfate maintains wider PPI and offers better postoperative pain relief compared to labetalol during induced hypotension in nasal surgery. TRIAL REGISTRATION: Institutional review board approval (ref: 6601/20-12-2020). CLINICALTRIAL: gov (ref: NCT04688203 , date of registration: 29 -12-2020).

Clinical Implication of the Acumen Hypotension Prediction Index for Reducing Intraoperative Haemorrhage in Patients Undergoing Lumbar Spinal Fusion Surgery: A Prospective Randomised Controlled Single-Blinded Trial.

We investigated the clinical implication of the Hypotension Prediction Index (HPI) in decreasing amount of surgical haemorrhage and requirements of blood transfusion compared to the conventional method (with vs. without HPI monitoring). A prospective, randomised controlled-trial of 19- to 73-year-old patients (n = 76) undergoing elective lumbar spinal fusion surgery was performed. According to the exclusion criteria, the patients were divided into the non-HPI (n = 33) and HPI (n = 35) groups. The targeted-induced hypotension systolic blood pressure was 80−100 mmHg (in both groups), with HPI > 85 (in the HPI group). Intraoperative bleeding was lower in the HPI group (299.3 ± 219.8 mL) than in the non-HPI group (532 ± 232.68 mL) (p = 0.001). The non-HPI group had a lower level of haemoglobin at the end of the surgery with a larger decline in levels. The incidence of postoperative transfusion of red blood cells was higher in the non-HPI group than in the HPI group (9 (27.3%) vs. 1 (2.9%)). The use of HPI monitoring may play a role in providing timely haemodynamic information that leads to improving the quality of induced hypotension care and to ameliorate intraoperative surgical blood loss and postoperative demand for blood transfusion in patients undergoing lumbar fusion surgery.

Comparative evaluation of propofol versus dexmedetomidine infusion for hypotensive anesthesia during functional endoscopic sinus surgery: a prospective randomized trial.

BACKGROUND: During functional endoscopic sinus surgery (FESS), intranasal bleeding affects operative field visibility and increases the frequency of complications. Therefore, hypotensive anesthesia is a widely used technique to improve surgical outcomes. This study aimed to compare the efficacy of propofol and dexmedetomidine infusion for hypotensive anesthesia in patients undergoing FESS. METHODS: This prospective randomized trial was conducted in 80 adult patients who were scheduled for FESS under general anesthesia. Patients were randomly divided into two groups: group P (n = 40) received propofol infusion of 100-200 µg/kg/min and group D (n = 40) received dexmedetomidine infusion with a loading dose of 1 µg/kg over 10 min after induction, followed by maintenance infusion of 0.4-0.8 µg/kg/h. Intraoperative blood loss, quality of the surgical field (Fromme- Boezaart scale), hemodynamic control, and patient recovery were recorded. Statistical analysis was performed using Student's t-test, chi-square test, and Mann-Whitney U test. RESULTS: The mean arterial pressure and heart rate were significantly lower in group D throughout the surgery than in group P. Blood loss was significantly higher in group P (100.73 ± 18.12 ml) than in group D (85.70 ± 18.56 ml). The average number of patients with Fromme's score 1/2/3 was comparable between the groups. Intraoperatively, only one incidence of bradycardia and hypotension was observed in group D (2.5%) compared to group P. CONCLUSIONS: Both dexmedetomidine and propofol are efficacious and safe drugs for facilitating controlled hypotension during FESS; however, dexmedetomidine provides better hemodynamic control and is associated with lesser blood loss without any significant adverse effects.

Androgens and Non-Genomic vascular responses in hypertension.

Arterial hypertension is a global public health concern. In the last few years, the interest in androgen deficiency has been growing, and the association between androgens and high blood pressure (BP) is still controversial. One purpose of this review was to summarize the available findings in order to clarify whether male sex steroid hormones have beneficial or harmful effect on BP. The second purpose was to enhance the recognition of the acute non-genomic sex-independent vasorelaxing effect of androgens. Remarkably, BP variation is expected to be a consequence of the androgen-induced vasorelaxation which reduces systemic BP; hence the in vivo vasodepressor, hypotensive, and antihypertensive responses of androgens were also analyzed. This article reviews the current understanding of the physiological regulation of vascular smooth muscle contractility by androgens. Additionally, it summarizes older and more recent data on androgens, and some of the possible underlying mechanisms of relaxation, structural-functional differences in the androgen molecules, and their designing ability to induce vasorelaxation. The clinical relevance of these findings in terms of designing future therapeutics mainly the 5-reduced metabolite of testosterone, 5ß-dihydrotestosterone, is also highlighted. Literature collected through a PubMed database search, as well as our experimental work, was used for the present review.

Comparison of Tranexamic acid, Remifentanil, and Hydralazine on the bleeding volume during Dacryocystorhinostomy surgery.

BACKGROUND: Bleeding in Dacryocystorhinostomy (DRC) limits the surgeon's sight and access. Tranexamic acid, Remifentanil, and Hydralazine reduce intraoperative blood loss. However, no study has been carried out to compare the efficacy of the latter drugs during DCR surgery. METHODS: Ninety healthy candidates for DCR surgery with chronic Dacryocystitis (aging 20-80) were randomly assigned in groups of 30 to receive low doses of Tranexamic acid (TXA) (10 mg/kg with a maximum dose of 1000 mg), Remifentanil (0.1 µ/kg), or Hydralazine (0.1 mg/kg). All drugs were infused over 15 minutes before the initiation of surgery. The primary outcome was the bleeding volume during the surgery and until 2 hours in recovery. This study was approved by the Iranian Registry of Clinical Trials with the code of IRCT20210614051574N10 (https://en.irct.ir/trial/62759). RESULTS: Thirty patients (mean age ± SD: 50.48±13.4) were investigated. Mean blood loss volume was lower in Remifentanil and Hydralazine groups compared with the TXA group (P<0.05); there was no significant difference (P>0.05) in bleeding volume between Remifentanil and Hydralazine groups (Tranexamic acid group: 146.83±91 ml, Remifentanil group: 77.6±52.1 ml, Hydralazine group: 80.0±48.7 ml, 95% confidence interval, P<0.05). CONCLUSION: Our results show that Remifentanil and Hydralazine are more effective than Tranexamic acid in bleeding control.

Comparison of norepinephrine and phenylephrine infusions for maintenance of haemodynamics following subarachnoid block in lower segment caeserean section.

BACKGROUND AND AIMS: Phenylephrine is the vasopressor of choice in spinal anaesthesia-induced maternal hypotension. However, it results in reflex bradycardia and decrease in cardiac output (CO), an effect that is perhaps less evident with the use of norepinephrine. We sought to evaluate the effect of phenylephrine and norepinephrine infusion on maternal systolic blood pressure (SBP), heart rate (HR), intraoperative nausea vomiting (IONV) and fatal Apgar scores. METHODS: A randomised double-blind study was conducted on 200 American Society of Anesthesiologists (ASA) II-III parturients undergoing caesarean section under subarachnoid block (SAB) who were randomised to two groups A and B to receive variable rate, manually controlled infusions of phenylephrine and norepinephrine targeting maintenance of SBP to 100% of the baseline value. Maternal haemodynamics especially episodes of hypotension, IONV and vasopressor consumption were observed and recorded. RESULTS: A statistically significant trend of lower SBP was observed during the first 6 min following intrathecal injection in group A (P value - 0.000). Though a greater number of parturients experienced ≥1 episode of hypotension in Group A vs Group B (13% vs 9%), the difference was, however, statistically insignificant. The incidence of bradycardia was higher in group A than in group B (16% vs 1%) and was found to be statistically significant (P < 0.05). The episodes of hypertension, IONV, maternal vasopressor consumption and neonatal Apgar score were comparable among both the groups. CONCLUSION: A dilute solution of norepinephrine infusion is comparably efficacious to the current gold standard vasopressor phenylephrine in maintaining blood pressure following spinal anaesthesia for caesarean delivery, with a significantly lower incidence of bradycardia.

Vasopressors for the Treatment and Prophylaxis of Spinal Induced Hypotension during Caesarean Section.

Vasopressors have currently become the mainstay therapy for the management of spinal-induced hypotension (SIH) as the major mechanism of hypotension after spinal anaesthesia is the loss of arteriolar tone produced by sympathetic block. Vasopressors for the prophylaxis and treatment of SIH have been the subject of a significant amount of research, yet remain an attractive and important clinical problem. This review will highlight controversies and recent research on the use of vasopressors for both prophylaxis and treatment of SIH. For decades, ephedrine was considered to be the best vasopressor for the management of maternal hypotension. However, its use has been reported to be associated with a 5-fold increased risk of foetal acidosis than phenylephrine. At present, phenylephrine is the vasopressor of choice for preventing and treating SIH at caesarean section. However, its use is often associated with a decreased heart rate and low cardiac output state owing to the lack of ß-mimetic activity. Norepinephrine has been introduced as an alternative vasopressor for preventing and treating SIH because of its additional ß-mimetic activity. However before its routine clinical use, a further series of studies are needed to establish its efficacy and safety for both the mother and foetus.

Intravenous norepinephrine and mephentermine for maintenance of blood pressure during spinal anaesthesia for caesarean section: An interventional double-blinded randomised trial.

BACKGROUND AND AIMS: Spinal anaesthesia induced hypotension (SAIH) and bradycardia may prove deleterious to both parturient and baby, hence vasopressors play a vital role in their management. Recent studies on norepinephrine as rescue vasopressor during subarachnoid block (SAB) enlighten its role for SAIH. This randomised double-blind trial was conducted to compare the effect of intermittent intravenous boluses of norepinephrine and frequently used mephentermine for management of SAIH in caesarean section (CS) to prove whether norepinephrine produces comparable effects or superior to mephentermine. METHODS: After approval from Institutional Ethics Committee and registration in Clinical Trials Registry India (CTRI/2019/06/019652), 256 parturients posted for elective CS under SAB were randomly allocated into Group-N and Group-M (n = 84) using chit system, who received boluses of intravenous norepinephrine 8µg and mephentermine 6mg for SAIH, respectively. Systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), Response%, Apgar score and maternal complications were analysed. RESULTS: The changes in SBP and DBP were comparable in both the groups. It was significantly low after SAB compared to baseline and significantly high compared to 1st hypotensive value in both the groups throughout the study period (<0.0001). HR was comparable for initial 10 min, thereafter it was significantly high in Group-M (<0.0001) till 40 min. Response% after the first bolus was significantly high in Group-N (59.30n ± 29.21 vs 39.78 ± 25.6; P = <0.0001). CONCLUSION: Intravenous norepinephrine is better than mephentermine with respect to high response% and stable maternal HR although both are equally effective in maintaining blood pressure following SAIH during elective CS.

Midodrine treatment in a patient with treprostinil-induced hypotension receiving hemodialysis.

PURPOSE: Use of the vasodilator midodrine for the treatment of treprostinil-induced hypotension is reported. SUMMARY: Intradialytic hypotension is a common complication of dialysis that increases patient mortality due to suboptimal ultrafiltration and interruption of hemodialysis. Midodrine is an α1 vasoconstrictor commonly used for the treatment of pulmonary arterial hypertension (PAH) and intradialytic hypotension. The safety of midodrine dosing at greater than 30 mg daily has not been established to date. A 49-year-old African-American man with a history of PAH and end-stage renal disease (ESRD) was receiving hemodialysis (HD) 3 times weekly. Subcutaneous treprostinil infusions were initiated for PAH, subsequently causing hypotension, with predialysis blood pressure values as low as 60/50 mm Hg. During a 6-month follow-up period, 38 of 62 dialysis sessions were interrupted or discontinued due to severe intradialytic hypotension. Counteraction of treprostinil effects was achieved by increasing the total daily midodrine dose from 30 mg to 90 mg over 6 months, with no remarkable adverse effects. In previously reported cases, maximum midodrine daily doses of 30 mg in nondialysis patients and 25 mg in patients with ESRD receiving hemodialysis were reported. The patient described here received a total daily dose of 90 mg, including 60 mg administered in divided doses for daily maintenance and 30-mg intradialytic doses; this was the highest daily midodrine dose reported to date. CONCLUSION: A 49-year-old patient tolerated 60-mg daily doses of midodrine along with 30-mg intradialytic doses for the management of treprostinil-induced hypotension and prevention of HD interruption, without adverse effects.