Reduction In Arterial Blood Pressure Research Articles

Use of Dexmedetomidine versus Nitroglycerine to Provide Hypotensive Anesthesia in ENT Surgeries (Functional Endoscopic Sinus Surgery)

Abstract Background controlled (deliberate/induced) hypotension is a technique by which the arterial blood pressure is lowered in a controllable manner to reduce surgical blood loss and improve the operative field visibility. There are pharmacological and nonpharmacological techniques for inducing hypotension. The nonpharmacological methods for deliberate hypotension include positioning and positive pressure ventilation to control venous return. Aim of the Work to evaluate the efficacy of dexmedetomidine (DEX) as a hypotensive agent in comparison to nitroglycerin (NTG) in FESS regarding the bloodless field, reduction of mean arterial blood pressure, decrease inhalational anesthetic requirements (MAC), decrease perioperative opioid requirements, increase the time to first postoperative analgesic request and recovery profile and increase hemodynamics stability. Patients and Methods we conducted this study on 20 patients who were planned to perform functional endoscopic sinus surgery and were randomly distributed into 2 equal groups: 10 patients received dexamedotomidine and equal number of patients received nitroglycerine. Serial measurements of mean arterial blood pressure and heart rate were obtained and records between both groups were compared. Results There were statistically significant differences between both groups regarding heart rate as mean values of heart rate were lower among dexamedotomidine group. There were no statistically significant differences between both groups regarding mean arterial blood pressure values at different time points during the operation. Regarding the period after stopping infusion, mean values of heart rate and blood pressure were lower among dexamedotomidine group than nitroglycerine group after 5 minutes and after 10 minutes and the differences had statistically significant differences. Regarding postoperative period, both groups were comparable regarding heart rate and blood pressure immediately postoperative. Conclusion From the results of this study, we could conclude that both Dexmedetomidine and Nitroglycerin can be effectively used in induced hypotensive anesthesia for ENT surgery as FESS. Both groups were comparable with intra operative MAP with no statistically significant differences. This study also show that Dexmedetomidine has added advantages as better haemodynamic stability than Nitroglycerin (No rebound HTN, no tachycardia). Has sedative and analgesic effect, reduce requirement of anesthetic agents and perioperative analgesia. Postoperative recovery score (Time to reach modified Aldert score more than nine significantly higher. Postoperative complication as nausea and vomiting is less.

Rapid changes in cerebrovascular compliance during vasovagal syncope.

The compensatory mechanisms supporting cerebral perfusion throughout head-up tilt (HUT) in patients with vasovagal syncope (VVS) remain unclear. We tested the hypothesis that increased cerebrovascular compliance (Ci) and decreased cerebrovascular resistance (CVR) support cerebral blood velocity (CBV) during pre-syncope in VVS. Finger arterial blood pressure (ABP) and right middle cerebral artery blood velocity (CBV) were recorded in 15 individuals diagnosed with VVS (n = 11 female, mean age: 40 ± 16years, mean body mass index: 24.9 ± 4.0kg/m2) at supine rest and during HUT (80 degree angle). Individual ABP and CBV waveforms during VVS were input into a modified Windkessel model to calculate Ci and ohmic CVR. Gosling's pulsatility index (Pi; pulse amplitude/mean CBV) was calculated. Diastolic ABP, systolic ABP, mean ABP (72 ± 11 to 51 ± 12mmHg), and CVR decreased progressively during presyncope (all P ≤ 0.04). As expected, systolic CBV was sustained (all P ≥ 0.29) while diastolic and mean CBV (51 ± 13 to 38 ± 13mmHg) fell during presyncope (all P ≤ 0.04). Both Ci and Pi increased during presyncope (128 ± 97 and 60 ± 41%, respectively; all P ≤ 0.049) and were positively correlated (R2 = 0.79, P < 0.01). Increased Ci contributed to changes in mean CBV (P < 0.01) but decreased CVR did not (P = 0.28). These data provide evidence that Ci increases during presyncope in patients with VVS and is likely involved in the maintenance of systolic CBV during a fall in diastolic CBV. However, this regulation is not sufficient to preserve CBV in the presence of such extreme and progressive reductions in ABP.

High-flow nasal cannula oxygen reduced hypoxemia in patients undergoing gastroscopy under general anesthesia at ultra-high altitude: a randomized controlled trial.

Hypoxemia can occur in people at ultra-high altitude (above 3500m) even at rest, and patients undergoing gastroscopy under general anesthesia have higher risk of hypoxemia. Supplementary oxygen via standard nasal cannula (SNC) is the standard of care for most patients who undergo gastroscopy under general anesthesia, which provides oxygen flow up to 15L/min. High-flow nasal cannula (HFNC) could deliver oxygen at a rate up to 60L/min, which is recommended by the American Society of Anesthesiologists Practice Guidelines. We speculated that the benefit with HFNC is more prominent in high-altitude areas, and aimed to compare the incidence of hypoxemia during gastroscopy under general anesthesia at ultra-high altitude with oxygen supply via either HFNC or SNC. The trial was registered at at Chinese Clinical Trial Registry (ChiCTR2100045513; date of registration on 18/04/2021). Adult patients undergoing gastroscopy with anesthesia (estimated duration of anesthesia at ≥ 15min) were randomized at a 1:1 ratio to receive HFNC oxygen or SNC oxygen. The primary outcome was hypoxemia (SpO2 < 90% for any duration). Secondary outcomes included severe hypoxemia (SpO2 < 75% for any duration or SpO2 < 90% but ≥ 75% for ≥ 60s) and hypotension, as defined by reduction of mean arterial blood pressure by ≥ 25% from the baseline. A total of 262 patients were enrolled: 129 in the HFNC group and 133 in the SNC group. All patients received the designated intervention. Student's t-test, Mann-Whitney U test and χ2 test were employed in the study. The rate of hypoxemia was 9.3% (12/129) in the HFNC group versus 36.8% (49/133) in the SNC group [risk ratio (95% confidence interval): 0.25(0.14-0.45); P < 0.001). The HFNC group also had lower rate of severe hypoxemia [0.0% (0/129) versus 11.3% (15/133); risk ratio (95% confidence interval): 0.03(0.00-0.55); P < 0.001, respectively]. The rate of hypotension did not differ between the 2 groups [22.5% (29/129) in HFNC group versus 21.1% (28/133) in SNC group; risk ratio (95% confidence interval): 1.07(0.67-1.69) ; P = 0.779]. HFNC oxygen reduced the incidence of hypoxemia during anesthesia in adult patients undergoing gastroscopy at ultra-high altitude.

ST-2560, a selective inhibitor of the NaV1.7 sodium channel, affects nocifensive and cardiovascular reflexes in non-human primates.

The voltage-gated sodium channel isoform NaV1.7 is a high-interest target for the development of non-opioid analgesics due to its preferential expression in pain-sensing neurons. NaV1.7 is also expressed in autonomic neurons, yet its contribution to involuntary visceral reflexes has received limited attention. The small molecule inhibitor ST-2560 was advanced into pain behaviour and cardiovascular models to understand the pharmacodynamic effects of selective inhibition of NaV1.7. Potency of ST-2560 at NaV1.7 and off-target ion channels was evaluated by whole-cell patch-clamp electrophysiology. Effects on nocifensive reflexes were assessed in non-human primate (NHP) behavioural models, employing the chemical capsaicin and mechanical stimuli. Cardiovascular parameters were monitored continuously in freely-moving, telemetered NHPs following administration of vehicle and ST-2560. ST-2560 is a potent inhibitor (IC50 = 39 nM) of NaV1.7 in primates with ≥1000-fold selectivity over other isoforms of the human NaV1.x family. Following systemic administration, ST-2560 (0.1-0.3 mg·kg-1, s.c.) suppressed noxious mechanical- and chemical-evoked reflexes at free plasma concentrations threefold to fivefold above NaV1.7 IC50. ST-2560 (0.1-1.0 mg·kg-1, s.c.) also produced changes in haemodynamic parameters, most notably a 10- to 20-mmHg reduction in systolic and diastolic arterial blood pressure, at similar exposures. Acute pharmacological inhibition of NaV1.7 is antinociceptive, but also has the potential to impact the cardiovascular system. Further work is merited to understand the role of NaV1.7 in autonomic ganglia involved in the control of heart rate and blood pressure, and the effect of selective NaV1.7 inhibition on cardiovascular function.

Rapid Changes in Cerebrovascular Compliance During Vasovagal Syncope

Background: The rapid reduction in arterial blood pressure (ABP) during vasovagal syncope (VVS) is associated with a characteristic decline in diastolic cerebral blood velocity (CBV) and maintained systolic CBV as measured by transcranial Doppler. This increased pulsatility was originally considered to be indicative of a “dysfunctional” increase in cerebrovascular resistance (CVR). Conversely, it may be due to increased cerebrovascular compliance (Ci) that partially attenuates the cerebral effects of rapid hypotension. We tested the hypothesis that Ci supports CBV during pre-syncope in VVS. Method: Finger ABP and right middle cerebral artery blood velocity (MCAv) were recorded from 15 otherwise healthy patients (n = 11 female, 40 ± 16 years, 24.9 ± 4.0 kg/m2) at rest and during head-up tilt (80°, 5 to 28 min). Individual ABP and CBV waveforms of every second heartbeat during VVS were input into a modified Windkessel model to calculate Ci and CVR. MCAv pulsatility was determined as pulse amplitude (systolic MCAv-diastolic MCAv) and Pulsatility Index (Pi; pulse amplitude/mean MCAv). Linear mixed models assessed the contribution of Ci to changes in CBV and Pi. Within-subject mediation analysis investigated the possibility of Ci mediating the relation between blood pressure (i.e., mean ABP and pulse pressure, PP) and cerebrovascular pulsatility. Results: Diastolic and systolic ABP decreased progressively during presyncope, resulting in a nadir reduction of mean ABP of Δ24 ± 9 mmHg at end-tilt (all p ≤ 0.04 vs mid-tilt). Mean MCAv decreased by 22 ± 12% prior to end-tilt (p &lt; 0.01 vs mid-tilt). CVR decreased progressively for 10s prior to end-tilt (p ≤ 0.04 vs mid-tilt). Pi increased significantly, with peak increases occurring at 4 s prior to end-tilt (77 ± 50%, p &lt; 0.01 vs mid-tilt). The increase in Ci (307 ± 223%, p &lt; 0.01 vs mid-tilt) significantly contributed to changes in MCAv (χ2 =10.6, p &lt; 0.01) and Pi (χ2 = 4.9, p = 0.03). Correlations of PP and ABP with Pi were not significant. However, PP was related to MCAv pulse amplitude (total effect: b = 1.57) and Ci ( b = -0.01, both p &lt; 0.01). Ci partially mediated (indirect effect: b = -0.78, p &lt; 0.01) the direct relation between PP and MCAv pulse amplitude ( b = 0.79, p = 0.01). Conclusion: These data provide evidence that Ci attenuates the fall in CBV under conditions of falling PP. Cerebrovascular regulation in VVS appears to be functioning as in healthy populations. However, this regulation is not suffcient to preserve flow in the presence of such extreme and rapid reductions in ABP. USRI — Western University, Natural Sciences and Engineering Research Council of Canada (NSERC, Grant No. RGPIN-2018-06255). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Comparison of Fentanyl, Ketamine, and Lidocaine Combined with Propofol Anesthesia in Patients with Crohn Disease Undergoing Colonoscopy.

BACKGROUND Colonoscopy is the predominant invasive procedure for Crohn disease (CD) patients. Opioids and propofol carry risks of respiratory and cardiovascular complications. This study aimed to evaluate whether substituting fentanyl with ketamine or lidocaine could diminish propofol usage and minimize adverse events. MATERIAL AND METHODS In total, 146 patients with CD scheduled for elective colonoscopy were assigned to anesthesia with fentanyl (n=47), ketamine (n=47), or lidocaine (n=55). Propofol was administered to achieve sufficient anesthesia. Measured outcomes in each group included propofol consumption, hypotension and desaturation incidents, adverse event types, consciousness recovery time, abdominal pain intensity, Aldrete scale, and Post Anaesthetic Discharge Scoring System (PADSS). RESULTS Patients administered fentanyl needed significantly more propofol (P=0.017) than those on ketamine, with lidocaine showing no notable difference (P=0.28). Desaturation was significantly less common in the ketamine and lidocaine groups than fentanyl group (P<0.001). The ketamine group experienced milder reductions in mean arterial (P=0.018) and systolic blood pressure (P<0.001). Recovery metrics (Aldrete and PADSS scores) were lower for fentanyl (P<0.001), although satisfaction and pain levels were consistent across all groups (P=0.797). Dizziness occurred less frequently with lidocaine than fentanyl (17.2%, P=0.018) and ketamine (15.1%, P=0.019), while metallic taste incidents were more prevalent in the lidocaine group (13.5%, P=0.04) than fentanyl group. CONCLUSIONS Using ketamine or lidocaine instead of fentanyl in anesthesia for colonoscopy in patients with CD significantly lowers propofol use, reduces desaturation events, maintains blood pressure more effectively, without increasing hypotension risk, and accelerates recovery, without negatively impacting adverse events or patient satisfaction.

The Effect of Mannitol and Hypertonic Sodium Administration on Hemodynamic Parameters Under LiDCO Monitoring in Patients Undergoing Elective Craniotomy

In craniotomy surgery, it is important to maintain hemodynamics and prevent the increase of intracranial pressure. Using semi-invasive methods such as LiDCO monitoring is a good option in this situation. This study aimed to evaluate the effectiveness of mannitol and hypertonic sodium on hemodynamic parameters in patients undergoing elective craniotomy. This randomized clinical trial was done on 40 patients of both genders. Patients whose ages were between 18-65 years, who had American Society of Anesthesiologists (ASA) score I and II, and who underwent craniotomy surgery were eligible for this study. Participants were divided into two groups receiving hypertonic sodium and mannitol. Hemodynamic parameters were evaluated before surgery, 20 minutes, and 60 minutes after surgery in both groups, under Lithium dilution cardiac output (LiDCO) monitoring. The results showed that there was no difference between groups in terms of the average fluid intake, the duration of the operation, the amount of urinary output, and the primary hemodynamic characteristics. Significant differences were recorded in the evaluation of hemodynamic parameters. The results demonstrated a reduction in systolic, diastolic, and mean arterial blood pressure during 20 to 60 minutes after mannitol injection compared to hypertonic sodium injection. Additionally, the effectiveness of both therapies on maintaining cardiac function was similar, but the use of mannitol led to a greater decrease in arterial and peripheral vascular resistance. It can be concluded that mannitol may be more effective than hypertonic sodium during craniotomy procedures in terms of reducing blood pressure monitored with LiDCO.

EFFICACY OF TOLAZOLINE AND VATINOXAN IN REDUCING ADVERSE EFFECTS OF BUTORPHANOL-AZAPERONE-MEDETOMIDINE IMMOBILIZATION IN ROCKY MOUNTAIN ELK (CERVUS CANADENSIS).

A mixture of butorphanol, azaperone, and medetomidine (BAM) is frequently used for immobilization of North American hoofstock. Common adverse effects include respiratory depression, hypoxemia, and bradycardia. In this nonblinded crossover study the efficacy of two a-2 adrenergic antagonists, tolazoline and vatinoxan, were evaluated in alleviating adverse effects of BAM in Rocky Mountain elk (Cervus canadensis). Early administration of these antagonists was hypothesized to cause an increase in heart rate, respiratory rate, partial pressure of oxygen (PaO2) and hemoglobin oxygen saturation (SpO2), as well as reduction in mean arterial blood pressure without affecting sedation levels. Eight captive adult female elk were immobilized on three separate occasions at least 14 d apart with 0.15 mg/kg butorphanol, 0.05 mg/kg azaperone, and 0.06 mg/kg medetomidine. Tolazoline (2 mg/kg IM), vatinoxan (3 mg/mg medetomidine IV) or sterile saline (2 ml IM) were administered 20 min postinduction. The BAM caused hypoxemia, bradycardia, and moderate hypertension, and because of the severe hypoxemia observed, all animals received intratracheal oxygen throughout immobilization. Heart rate, respiratory rate, rectal temperature, SpO2, PaO2, and systolic, diastolic, and mean arterial blood pressure were monitored every 5 min throughout the immobilization. Intramuscular tolazoline caused a brief but significant drop in mean arterial pressure compared with controls and a brief but nonsignificant increase in heart rate. Vatinoxan caused a significant drop in blood pressure and a brief significant increase in heart rate. Changes in respiratory rates and PaO2 were not observed with either antagonist; however, all animals received oxygen, which may have influenced this result. The depth of sedation was unchanged after administration of either drug.

Predictors of cardiovascular and renal complications in patients with resistant arterial hypertension during long-term follow-up

The aim – to evaluate the incidence of cardiovascular and renal complications and its predictors in resistant hypertensive (RH) patients during the long-term follow-up.Materials and methods. The frequency of cardiovascular and renal events was studied in 240 true resistant hypertensive patients. The duration of observation was 5.1±0.1 years. The comparison group consisted of 228 patients with controlled arterial hypertension (CAH) on a triple combination antihypertensive therapy. Cardiovascular endpoints included stroke/transient ischemic attack, myocardial infarction, cardiovascular death, myocardial revascularization, development of atrial fibrillation, hospitalization due to heart failure, and lower limb arterial disease. Kidney outcomes included dialysis or GFR decline by 40 % or greater. All the endpoints formed a composite primary endpoint. New cases of type 2 diabetes mellitus were also estimated.Results and discussion. The patients with resistant hypertension on multi-component antihypertensive therapy and significant reduction in arterial blood pressure (BP) levels (achievement of controlled office BP in 49.6 % of patients, office and ambulatory BP in 34.2 % of patients), maintained a higher risk of cardiovascular and renal events compared to patients with controlled arterial hypertension. It was found that the frequency of occurrence of the composite primary endpoint in resistant hypertensive patients was four times higher than in the group of patients with controlled hypertension – 30.0 % (72/240) versus 7.0 % (16/228) (p=0.001). The frequency of new cases of type 2 diabetes mellitus in patients with RH exceeded compared to CAH patients by 3.7 times (p=0.03).Conclusions. Independent predictors of the risk of cardiovascular and renal complications in patients with RH were the initial indicators of circulating endothelial progenitor cells if their concentration in the blood was ≤ 1818 cells/ml (HR 0.41; 95 % CI (0.21–0.79); p=0.007), the content of citrulline in the blood is more than 68 μmol/l (HR 1.13; 95 % CI (1.07–1.20); p&lt;0.001); value of initial average daily systolic BP &gt; 163 mm Hg (HR 1.10; 95 % CI (1.03–1.18); p=0.008).

Effect of sitting time on the vasopressor requirement in elderly patients after spinal anesthesia: A randomized controlled study

ABSTRACT Background Neuraxial anesthesia appears to be a highly recommended, well-accepted technique for minimizing perioperative adverse effects in elderly patients. This research was designed to compare the impact of sitting for one, three, and 5 min on ephedrine consumption following spinal anesthesia in the elderly. Methods This randomized, controlled, double-blinded trial was conducted on 66 patients above 65 years undergoing surgeries under spinal anesthesia. Patients were randomly assigned to three equal groups. Patients received spinal anesthesia and then sat before they began to lie down for 1 min in the sitting-1 group, 3 min in the sitting-3 group, and 5 min in the sitting-5 group. Results The most reduction of mean arterial blood pressure (MAP) is in the Sitting-1 group, followed by the Sitting-3 group, and finally, the Sitting-5 group (p < 0.05). The most needed ephedrine was in the sitting-1 group (10 patients), followed by the sitting-3 (6 patients) and then the sitting-5 group (one patient) (p < 0.05). The sensory level was significantly higher in the sitting-1 group, followed by the sitting-3 and then sitting-5 group (p < 0.001). Conclusions Sitting for 5 min after spinal anesthesia in elderly patients decreases the ephedrine requirement and maintains adequate sensory block for surgery.

Acute and adaptive cardiovascular and metabolic effects of passive heat therapy or high-intensity interval training in patients with severe lower-limb osteoarthritis.

Exercise is painful and difficult to perform for patients with severe lower-limb osteoarthritis; consequently, reduced physical activity contributes to increased cardiometabolic disease risk. The aim of this study was to characterize the acute and adaptive cardiovascular and metabolic effects of two low or no impact therapies in patients with severe lower-limb osteoarthritis: passive heat therapy (Heat) and high-intensity interval training (HIIT) utilizing primarily the unaffected limbs, compared to a control intervention of home-based exercise (Home). Participants completed up to 12 weeks of either Heat (20-30 min immersed in 40°C water followed by ~15-min light resistance exercise), HIIT (6-8 × 60-s intervals on a cross-trainer or arm ergometer at ~90-100% peak O2 ) or Home (~15-min light resistance exercise); all 3 sessions/week. Reductions in systolic (12 & 10 mm Hg), diastolic (7 & 4 mm Hg), and mean arterial (8 & 6 mm Hg) blood pressure (BP) were observed following one bout of Heat or HIIT exposure, lasting for the duration of the 20-min monitoring period. Across the interventions (i.e., 12 weeks), resting systolic BP and diastolic BP decreased with Heat (-9 & -4 mm Hg; p < 0.001) and HIIT (-7 & -3 mm Hg; p ≤ 0.011), but not Home (0 & 0 mm Hg; p ≥ 0.785). The systolic and diastolic BP responses to an acute exposure of Heat or HIIT in the first intervention session were moderately correlated with adaptive responses across the intervention (r ≥ 0.54, p ≤ 0.005). Neither intervention improved indices of glycemic control (p = 0.310). In summary, both Heat and HIIT induced potent immediate and adaptive hypotensive effects, and the acute response was moderately predictive of the long-term response.

A Survey on Monitoring and Management of Cerebral Vasospasm and Delayed Cerebral Ischemia After Subarachnoid Hemorrhage: The Mantra Study.

Cerebral infarction from delayed cerebral ischemia (DCI) is a leading cause of poor neurological outcome after aneurysmal subarachnoid hemorrhage (aSAH). We performed an international clinical practice survey to identify monitoring and management strategies for cerebral vasospasm associated with DCI in aSAH patients requiring intensive care unit admission. The survey questionnaire was available on the European Society of Intensive Care Medicine (May 2021-June 2022) and Neurocritical Care Society (April - June 2022) websites following endorsement by these societies. There were 292 respondents from 240 centers in 38 countries. In conscious aSAH patients or those able to tolerate an interruption of sedation, neurological examination was the most frequently used diagnostic modality to detect delayed neurological deficits related to DCI caused by cerebral vasospasm (278 respondents, 95.2%), while in unconscious patients transcranial Doppler/cerebral ultrasound was most frequently used modality (200, 68.5%). Computed tomography angiography was mostly used to confirm the presence of vasospasm as a cause of DCI. Nimodipine was administered for DCI prophylaxis by the majority of the respondents (257, 88%), mostly by an enteral route (206, 71.3%). If there was a significant reduction in arterial blood pressure after nimodipine administration, a vasopressor was added and nimodipine dosage unchanged (131, 45.6%) or reduced (122, 42.5%). Induced hypertension was used by 244 (85%) respondents as first-line management of DCI related to vasospasm; 168 (59.6%) respondents used an intra-arterial procedure as second-line therapy. This survey demonstrated variability in monitoring and management strategies for DCI related to vasospasm after aSAH. These findings may be helpful in promoting educational programs and future research.

Assessment of hemodynamic significance of renal artery stenoses in endovascular treatment of resistant vasorenal arterial hypertension

Objective. To determine the significance of renal artery stenosis according to different methods of assessing the functional significance of stenosis and to evaluate the safety and efficacy of stenting of unilateral renal artery stenosis after 6 months and 1 year according to office BP and ABPM.Materials and methods. The study included 44 patients with resistant arterial hypertension and renal artery stenosis (mean age 69 ± 11 years), while receiving multicomponent antihypertensive therapy, including diuretic. After assessing the degree of RA stenosis according to selective angiography and additional methods of assessing the functional significance of RA stenosis (iFR, Pd/Pa, translesional gradient and FFR) the patients underwent RA stenting. The safety of the procedure was assessed by creatinine and glomerular filtration rate dynamics (MDRD equation). The effectiveness of the procedure was study according to office blood pressure (BP) and ambulatory BP monitoring (ABPM).Results. According to the results of angiography, the patients were divided into two groups: group A – patients with subtotal PA stenosis (&gt; 90%) and group B – patients with moderate stenosis (60-90%), who underwent additional assessment of the functional significance of stenosis. The immediate angiographic result in both groups was optimal (the degree of residual stenosis was less than 5%). In group B, after stent implantation in the PA, there was a decrease of the translesional gradient by 38 ± 10 mm Hg (p &lt; 0,0001), FFR &gt; 0,8(p &lt; 0.0001). iFR &gt; 0.89, Pd/Pa&gt;0.9 (p = 0,093). In both groups, there was a significantly significant reduction in arterial blood pressure at distant times, according to clinical BP measurement and ABPM.Conclusion. The measurement of such parameters as translesional gradient and fractional reserve is the most reliable in assessing the hemodynamic significance of PA stenosis in comparison with iFR and Pd/Pa measurements in patients with moderate PA stenosis. PA stenting in patients with uncontrolled resistant AH and severe renal artery lesions, as well as moderate stenosis confirmed by additional methods of stenosis functional significance assessment is reasonable to consider in order to enhance the antihypertensive effect.

Optimization of respiratory-gated auricular vagus afferent nerve stimulation for the modulation of blood pressure in hypertension.

The objective of this pilot study was to identify frequency-dependent effects of respiratory-gated auricular vagus afferent nerve stimulation (RAVANS) on the regulation of blood pressure and heart rate variability in hypertensive subjects and examine potential differential effects by sex/gender or race. Twenty hypertensive subjects (54.55 ± 6.23 years of age; 12 females and 8 males) were included in a within-person experimental design and underwent five stimulation sessions where they received RAVANS at different frequencies (i.e., 2 Hz, 10 Hz, 25 Hz, 100 Hz, or sham stimulation) in a randomized order. EKG and continuous blood pressure signals were collected during a 10-min baseline, 30-min stimulation, and 10-min post-stimulation periods. Generalized estimating equations (GEE) adjusted for baseline measures were used to evaluate frequency-dependent effects of RAVANS on heart rate, high frequency power, and blood pressure measures, including analyses stratified by sex and race. Administration of RAVANS at 100 Hz had significant overall effects on the reduction of heart rate (β = -2.03, p = 0.002). It was also associated with a significant reduction of diastolic (β = -1.90, p = 0.01) and mean arterial blood pressure (β = -2.23, p = 0.002) in Black hypertensive participants and heart rate in female subjects (β = -2.83, p = 0.01) during the post-stimulation period when compared to sham. Respiratory-gated auricular vagus afferent nerve stimulation exhibits frequency-dependent rapid effects on the modulation of heart rate and blood pressure in hypertensive patients that may further differ by race and sex. Our findings highlight the need for the development of optimized stimulation protocols that achieve the greatest effects on the modulation of physiological and clinical outcomes in this population.

Assessment of safety and feasibility of non-invasive vagus nerve stimulation for treatment of acute stroke

BackgroundNon-invasive vagus nerve stimulation (nVNS) using a hand-held stimulator placed on the neck is an FDA-approved treatment for primary headache disorders. The safety of nVNS is unknown in stroke patients. ObjectiveTo assess the safety and feasibility of nVNS for the acute treatment of stroke. MethodsTR-VENUS (clinicaltrials.gov identifier NCT03733431) was a randomized, sham-controlled, open-label, multicenter trial conducted in patients with acute ischemic stroke (IS) or intracerebral hemorrhage (ICH). Patients were randomly assigned to standard-dose nVNS, high-dose nVNS, or sham stimulation. The primary endpoint was a composite safety outcome defined as bradycardia or reduction in mean arterial blood pressure during treatment or progression of neurological or death within 24 h of treatment. The feasibility endpoints were the proportion of eligible subjects receiving nVNS within 6 h of symptom onset and the proportion completing all pre-specified treatment doses. Efficacy assessments included infarct growth from baseline to 24 h after treatment. ResultsSixty-nine patients (61 IS, 8 ICH) completed the study. The composite safety outcome was achieved in 32.0% in sham and 47.7% in nVNS group (p = 0.203). Treatment was initiated in all but two randomized patients. All dosed subjects received 100% of prespecified stimulations. A non-significant reduction in infarct growth was observed in the high-dose nVNS group (184.2% in sham vs. 63.3% in high-dose nVNS; p = 0.109). ConclusionsThe results of this study suggest that nVNS may be safe and feasible in the setting of acute stroke. These findings support further development of nVNS as a potential treatment for acute ischemic stroke.

Effects of a catechins-enriched diet associated with moderate physical exercise in the prevention of hypertension in spontaneously hypertensive rats

Hypertension represents the main risk factor for the onset of cardiovascular diseases. Pharmacological treatments to control hypertension have been associated with new treatments involving physical activity and/or the intake of natural components (nutraceuticals). We here report the effects produced by a combination of a natural component (catechins) and a moderate exercise program on the development of hypertension in spontaneous hypertensive rats compared with those of each individual treatment. Arterial blood pressure and heart rate were measured with a non-invasive method in 28 rats randomly assigned to four groups: rats subjected to moderate physical exercise; rats with a catechins-enriched diet; rats subjected to moderate physical exercise combined with a catechins-enriched diet; control, untreated-rats left to age. All treatments were applied for 6 weeks. The statistical analysis revealed that the three treatments significantly reduced the weekly increase in arterial blood pressure observed in control rats (SBP, P < 0.0001; DBP, P = 0.005). However, the reduction of arterial blood pressure induced by combined treatments was not higher than that induced by the single treatment, but more prolonged. All treatments showed strong antioxidative properties. Our data show that physical activity and a diet enriched with catechins individually have an important hypotensive effect, while the association did not produce a higher hypotensive effect than the single treatment, even if it was able to decrease blood pressure for a longer time. These findings have important implications for developing a protocol to apply in novel hypertension prevention procedures.

A Comparative Study of the Efficacy of Intravenous Bolus of Mephentermine and Phenylephrine in Maintaining Arterial Blood Pressure During Spinal Anaesthesia in Caesarean Section

BACKGROUND&#x0D; Spinal anaesthesia is the most popular and elegant approach for obstetric patients undergoing caesarean section due to its several advantages. Hypotension resulting from sympathectomy due to subarachnoid block can have detrimental effects on the foetus as well as the mother, so needs to be prevented and treated adequately. Vasopressors for the treatment of hypotension have a well-established role as vasodilatation is the primary cause of the reduction in arterial blood pressure. The primary objective of the study was to compare mephentermine and phenylephrine with respect to their clinical efficacy in maintaining arterial blood pressure during spinal anaesthesia in caesarean section and the secondary objective was to determine any untoward effects of the study drugs on the mother and foetus.&#x0D; METHODS&#x0D; This prospective, randomized, comparative, double-blind study was conducted among 90 pregnant women of ASA-I physical status having singleton pregnancies in the age group of 18-30 years undergoing elective as well as emergency caesarean section and were randomly allocated in to two groups. Group M (n=45), received 6 mg of mephenterine as an intravenous bolus (volume made up to 1 ml) and Group P (n=45), received 100 g of phenylephrine as intravenous bolus (volume made up to 1 ml) whenever hypotension occurred after spinal anaesthesia. A comparison of the mean values among the two groups was done using a student t-test. To compare more than two variables, ANOVA test was used. The p-values of less than 0.05 were considered statistically significant.&#x0D; RESULTS&#x0D; The systolic blood pressure, diastolic blood pressure and mean arterial pressure remained significantly high (P &lt; 0.05) in the phenylephrine group as compared to the mephentermine group. The phenylephrine group also showed a significant fall (P &lt; 0.05) in heart rate as compared to the mephentermine group.&#x0D; CONCLUSIONS&#x0D; Both the drugs were effective in treating the hypotension caused by spinal anaesthesia without any adverse effects on the mother as well as on neonatal outcome but phenylephrine had a quicker onset, better maintenance of blood pressure and can be preferred in patients in whom tachycardia is undesirable.

Evaluation of the Cardiac Electrophysiological and Haemodynamic Effects of Elsholtzia ciliata Essential Oil on Swine.

The demand for the development of novel medicines with few side effects and no proarrhythmic properties is increasing. Extensive research on herbal extracts has been conducted with the expectation that the compounds will exert precise effects without harmful side effects. Elsholtzia ciliata (Thunb.) Hyl. essential oil (EO) possesses antiarrhythmic properties similar to those of class 1B antiarrhythmics, such as prolonging myocardial activation of the QRS complex and shortening the QT interval. In this study, we determined the kinetic profile of EO phytocompounds and the effects of EO on heart electrical activity and arterial blood pressure. For this study, we chose to use local breed pigs that were anaesthetized. The effects of an intravenous bolus of EO on ECG parameters, arterial blood pressure, heart rate variability, and blood levels of haematological and biochemical parameters were registered and evaluated. Following an intravenous injection of a bolus, EO exerted a vasodilatory effect, resulting in significant reductions in arterial blood pressure. EO also increased the heart rate and altered ECG parameters. The bolus of EO prolonged the QRS complex, shortened the QT interval, and nonmonotonically altered the PQ interval. After the administration of a bolus of EO, the activity of the autonomic nervous system was altered. This study confirms that EO possesses similar properties to class 1B antiarrhythmics and exerts a hypotensive effect; it reduces arterial blood pressure possibly by modulating peripheral vascular resistance.

Comparison of intravenous labetalol and hydralazine for severe hypertension in pregnancy in Northeastern Nigeria: A randomized controlled trial.

The objectives were to compare the efficacy and safety of intravenous hydralazine and labetalol for acutely lowering severe hypertension in pregnancy. This was a superiority parallel double-blinded randomized controlled trial conducted from October 2018 to June 2019 in two hospitals in Gombe, Nigeria. Pregnant women with a live singleton fetus at gestational age of at least 28weeks with severe hypertension were randomized (60 per group) to receive incremental doses of either intravenous labetalol (20mg; 40mg; 80mg; 80mg; and 80mg) or 10mg of intravenous hydralazine - up to a maximum of 5 doses - until the target blood pressure was achieved or the study was terminated. The main outcome measures were the mean reduction in mean arterial blood pressure and occurrence of persistent hypertension. Other endpoints were maternal side-effects, perinatal death, Apgar score at birth and SCBU admission. One hundred and thirteen patients' data were analyzed (fifty-six [56] in the hydralazine group and fifty-seven [57] in the labetalol group). There were no significant differences in the fall of the mean arterial blood pressure (labetalol; 24.19mmHg/hydralazine; 27.68mmHg) (p=0.192), maternal side effects, perinatal deaths, Apgar scores and SCBU admission between the two groups. Hydralazine, however, produced a more marked reduction in diastolic blood pressure than labetalol (p=0.012). Both labetalol and hydralazine are effective for acute blood pressure control in pregnancy with a similar safety profile. This study was self-funded and registered in the Pan African Clinical Trials Registry (www.pactr.orgPACTR202010738538062).

Reliability of Pre-Induction Inferior Vena Cava Assessment with Ultrasound for the Prediction of Post-Induction Hypotension in Neurosurgical Patients Undergoing Intracranial Surgery

Hypotension is one of the most common complications following induction of general anesthesia. Preemptive diagnosis and correcting the hypovolemic status can reduce the incidence of post-induction hypotension. However, an association between preoperative volume status and severity of post-induction hypotension has not been established in neurosurgical patients. We hypothesized that preoperative ultrasonographic assessment of intravascular volume status can be used to predict post-induction hypotension in neurosurgical patients. Our study objective was to establish the relationship between pre-induction maximum inferior vena cava (IVC) diameter, collapsibility index (CI), and post-induction reduction in mean arterial blood pressure in neurosurgical patients. A prospective observational study was conducted including 100 patients undergoing elective intracranial surgeries. IVC assessment was done before induction of general anesthesia. Receiver operating characteristic (ROC) curve analysis was used to determine the cutoff values of maximum and minimum IVC diameter (IVCDmax and IVCDmin, respectively) and CI for prediction of hypotension. Post-induction hypotension was observed in 41% patients. Patients with small IVCDmax and higher CI% developed hypotension. The areas under the ROC curve (AUCs) were 0.64 (0.53-0.75) for IVCDmax and 0.69 (0.59-0.80) for IVCDmin. The optimal cutoff values were1.38 cm for IVCDmax and 0.94 cm for IVCDmin. The AUC for CI was 0.65 (0.54-0.77) and the optimal cutoff value was 37.5%. Pre-induction IVC assessment with ultrasound is a reliable method to predict post-induction hypotension resulting from hypovolemia in neurosurgical patients.