Reduction In Arterial 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.

Safety and Efficacy of SGLT2 Inhibitors for Amyloid Light-Chain Cardiomyopathy

BackgroundSodium-glucose cotransporter-2 inhibitors (SGLT2i) have demonstrated benefit in patients with heart failure, but minimal data exists around the use of these medications in amyloid light-chain cardiomyopathy (AL-CM). We performed a retrospective study assessing the safety and efficacy of SGLT2i in AL-CM. MethodsWe queried our institutional registry and identified 27 AL-CM patients who received SGLT2i. The safety analysis included all 27 patients and assessed SGLT2i-associated adverse events, hospitalizations, and deaths. To decrease confounding, the efficacy analysis included only a subset of patients with stable disease (on stable anti-plasma cell therapy for ≥2 months prior to baseline and achieved at least a hematologic Very Good Partial Response) and compared disease marker changes in these patients (n=17) with those of a contemporaneous untreated control cohort from our registry (n=21). ResultsThe mean age of the overall population was 68.6 (standard deviation 9.4) years. Seven (14.6%) patients had diabetes, and 19 (39.6%) had chronic kidney disease. In the safety analysis, median follow-up time was 10.9 (interquartile range 7.2) months. Two (7.4%) patients discontinued SGLT2i due to hypovolemia and genital irritation, and 6 (22.2%) additional patients temporarily held SGLT2i due to an adverse event, commonly related to volume depletion. Thirteen hospitalizations, all considered unrelated to SGLT2i use, and no deaths occurred. In the efficacy analysis, SGLT2i-treated patients had more severe disease at baseline than controls, demonstrating significantly higher median troponin-T and loop diuretic dose (P<0.05). Compared with controls, SGLT2i treatment was associated with significantly greater reductions in loop diuretic dose (P<0.001) and NTproBNP (P=0.033) across 3-, 6-, and 12-month follow-up timepoints. SGLT2i treatment was also associated with a significantly greater reduction in mean arterial pressure at 12 months (P=0.031) but not at other timepoints. No significant differences were observed on changes in weight, eGFR, troponin-T, proteinuria, or albumin. ConclusionsIn this small-scale retrospective study, we demonstrate that SGLT2i is well-tolerated by most patients with AL-CM, but volume depletion symptoms may limit continuous use. SGLT2i may aid management of congestion in AL-CM as evidenced by reduced diuretic dose and NTproBNP without adverse renal effects. Larger long-term studies are needed to build on our findings.

The Antihypertensive Effect of Marchin-13 Tang on L-NAME-induced Hypertension in Rats

Marchin-13 Tang is a traditional Mongolian medicine widely used to reduce blood pressure. The study aimed to evaluate the anti-hypertensive effect of Marchin-13 (M-13) Tang in the L-NAME-induced model of hypertension. The biological composition activity of M-13 Tang was examined using the UV spectrophotometric method. The experimental groups induced Hypertension models by L-NAME 40 mg/kg. The concentrations of serum nitric oxide (NO), Angiotensin-Converting Enzyme (ACE), superoxide dismutase (SOD), malondialdehyde (MDA), and catalase (CAT) were measured in M-13 Tang treatment groups by enzyme-linked immunosorbent assay (ELISA). The content of total phenolics was measured at 2.96±0.16%, while flavonoids were found to be present at a level of 1.81±0.1%. The reductions in mean arterial pressure (MAP) were statistically significant. They were observed from day 14 to day 21 after giving M-13 Tang at 90 mg/kg and 180 mg/kg (p&lt;0.01). Moreover, treated with M-13 Tang 90 mg/kg and 180 mg/kg groups, serum levels of NO, SOD, and CAT were significantly (p&lt;0.01) increased compared with the L-NAME (40 mg/kg) group. The levels of MDA and ACE showed a significant decrease in both the Marchin-13 Tang-treated groups compared to the L-NAME group (p&lt;0.05). The results of our study illustrate that Marchin-13 effectively reduced blood pressure by mitigating oxidative stress, enhancing NO production, and decreasing ACE levels in hypertensive rats induced by L-NAME.

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.

Cerebrovascular Compliance during Progressive Hypotension in Patients with Autonomic Failure

Background: Cerebral perfusion during reductions in arterial pressure (AP) can be supported transiently by a Windkessel mechanism that increases cerebrovascular compliance (Ci). This defense mechanism exists in healthy participants during rapid standing and in patients during vasovagal syncope. However, it remains unknown whether the rise in Ci with falling AP exhibits a threshold effect. Thus, we tested the hypothesis that increased Ci is passive to a reduction in AP and starts to increase only after a threshold has been reached. To test this hypothesis, it was necessary to study a population that tolerates progressive large reductions in BP without a loss of consciousness. Therefore, we analyzed Ci changes during a graded head-up tilt (HUT) from patients with autonomic failure (AF). Methods: Finger AP and right middle cerebral artery blood velocity (MCAv) were recorded from 5 AF patients (n = 5 male, 61 ± 23 years, 25 ± 5 kg/m2) at supine rest and during graded-HUT (30, 45, 60 degrees). Tilt gradients increased incrementally every 5 minutes until AP reached a critically low value prompting termination of HUT. The total time in HUT was 11 ± 4 min. Individual AP and MCAv waveforms during supine rest and graded HUT (one waveform every 5 s) were assessed with a modified Windkessel model to calculate Ci and cerebrovascular resistance (CVR). Pulse pressure (PP) was calculated as systolic AP − diastolic AP. A threshold value for the increase in Ci was determined as five consecutive cardiac cycles greater than the average supine Ci plus 2 standard deviations. Results: Graded HUT resulted in an overall reduction in AP (85 ± 18 to 50 ± 7 mmHg), PP (72 ± 22 to 32 ± 19 mmHg), mean MCAv (62 ± 12 to 35 ± 7 cm/s), and CVR (1.4 ± 0.1 to 1.0 ± 0.3 mmHg/cm/s; all p &lt; 0.05 vs supine). Ci increased by 905 ± 756% (p = 0.04 vs supine). The threshold effect was evident as Ci began to increase progressively after PP fell by 15 ± 3 mmHg and AP fell by 12 ± 2 mmHg. Conclusions: Our results provide evidence that Ci increases after a threshold reduction in PP and AP in the apparent absence of autonomic support. These data support the idea that increasing Ci during reductions in AP represents a pressure-dependent Windkessel mechanism. Of interest, our findings provide clinical insight into how AF patients compensate for such large reductions in pressure without the assistance of CVR as a defense mechanism. NSERC USRA — 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.

Evaluation of the Efficacy and Safety of Nicardipine versus Clevidipine for Blood Pressure Control in Hypertensive Crisis

BackgroundHypertensive crisis is an acute increase in blood pressure greater than 180/120 mmHg. A titratable antihypertensive agent is preferred to acutely lower blood pressure in a controlled way and prevent an abrupt overcorrection. Nicardipine and clevidipine are both dihydropyridine calcium channel blockers that provide unique benefits for blood pressure control. ObjectiveThe purpose of this study was to compare the efficacy and safety of nicardipine or clevidipine for blood pressure control in the setting of hypertensive crisis. MethodsThis was a single-center, retrospective cohort study. Eligible patients received either nicardipine or clevidipine for the treatment of hypertensive crisis. The primary outcome was achievement of 25% reduction in mean arterial pressure (MAP) at 1 hour. The secondary outcome was achievement of a systolic blood pressure (SBP) of < 160 mmHg at 2-6 hours from the start of the infusion. ResultsThis study included a total of 156 patients with 74 in the nicardipine group and 82 in the clevidipine group. The SBP on admission and at the start of the infusion was similar between groups. There was no difference between groups in achieving a 25% reduction in MAP at one hour. Nicardipine achieved a SBP goal of < 160 mmHg at 2-6 hours significantly more often than the clevidipine group (89.2% vs 73.2%; p-value 0.011). ConclusionThere is no difference between agents for initial blood pressure control in the treatment of hypertensive crisis. Nicardipine showed more sustained SBP control with a lower risk of rebound hypertension and a significant cost savings as compared to clevidipine.

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.

Physiologic Validation of the Compensatory Reserve Metric Obtained From Pulse Oximetry Waveforms

Background: The compensatory reserve metric (CRM) provides a novel marker of hemodynamic status in prediction of sudden cardiovascular decompensation during central hypovolemia. The CRM has previously been calculated using arterial waveforms obtained from a photoplethysmographic volume-clamp technique. However, the in-field use of pulse oximetry is becoming more prominent in research and medicine. To improve in-field applicability of the CRM, this project aimed to validate pulse-oximetry derived CRM values relative to physiologic data during simulated hemorrhage through application of lower body negative pressure (LBNP). Methods: Forty-nine healthy adults (25 females) underwent a graded LBNP protocol with the following 5-minute stages: -0, -15, -30, -45, -60, -70, -80, -90, and 100 mmHg, or until the onset of pre-syncopal symptoms (tolerance) was reached. Arterial waveforms were sampled using pulse oximetry (Massimo Radical 7). The CRM was calculated using a validated one-dimensional convolutional neural network. A brachial artery catheter was used to measure intraarterial pressure. A 3-lead ECG was used to measure heart rate. SpO2 was measured using pulse oximetry. Cardiac output and stroke volume were estimated using the photoplethysmographic volume-clamp. Data were binned for the last thirty seconds of each completed stage, and at tolerance. Fixed-effect linear mixed models with repeated measures were used to examine the association between CRM values and physiologic variables. A priori significance was set at P&lt;0.05. Results: The median LBNP stage reached was 70 mmHg (Range: 45-100 mmHg). Relative to baseline, at tolerance there was a 50±12% ( P&lt;0.001) mean reduction in stroke volume, 65±27% ( P&lt;0.001) increase in heart rate, 18±8% ( P&lt;0.001) reduction in mean arterial pressure, 21±7% ( P&lt;0.001) systolic blood pressure, 8±9% ( P&lt;0.001) diastolic blood pressure, and 39±12% ( P&lt;0.001) pulse pressure. The CRM obtained using pulse oximetry was significantly associated with a reduction in stroke volume ( P&lt;0.001), increase in heart rate ( P&lt;0.001), and reductions in systolic ( P=0.033), diastolic ( P=0.036), and pulse pressure ( P=0.002). There was no statistically significant association between CRM and cardiac output ( P=0.421), SpO2 ( P=0.408), or mean arterial pressure ( P=0.214). Conclusion: The CRM obtained using pulse oximetry may be a valid, reliable marker of hemodynamic status with promising in-field applications. Future studies warrant investigation of feasibility and applicability within various contexts ranging from the operating room to the battlefield. The presented work was funded in part by the Congressionally Directed Medical Research Program (Award No. DM180240) and Offce of Naval Research (Awards No. N00014-18-D-7001 and N00014-19-C-2017). 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.

Clinical usefulness of endothelial progenitor cells in predicting the efficacy of riociguat in chronic thromboembolic pulmonary hypertension.

Endothelial dysfunction is important in the pathology of pulmonary hypertension, and circulating endothelial progenitor cells (EPCs) have been studied to evaluate endothelial dysfunction. In patients with chronic thromboembolic pulmonary hypertension (CTEPH), riociguat reportedly increases the number of circulating EPCs. However, the relationship between EPC numbers at baseline and changes in clinical parameters after riociguat administration has not been fully elucidated. Here, we evaluated 27 treatment-naïve patients with CTEPH and analyzed the relationships between EPC number at diagnosis and clinical variables (age, hemodynamics, atrial blood gas parameters, brain natriuretic peptide, and exercise tolerance) before and after riociguat initiation. EPCs were defined as CD45dim CD34+ CD133+ cells and measured by flow cytometry. A low number of circulating EPCs at diagnosis was significantly correlated with increased reductions in mean pulmonary arterial pressure (mPAP) (correlation coefficient = 0.535, P = 0.004) and right atrial pressure (correlation coefficient = 0.618, P = 0.001) upon riociguat treatment. We then divided the study population into two groups according to the mPAP change: a weak-response group (a decrease in mPAP of 4 mmHg or less) and a strong-response group (a decrease in mPAP of more than 4 mmHg). The number of EPCs at diagnosis was significantly lower in the strong-response group than in the weak-response group (P = 0.022), but there were no significant differences in other clinical variables or in medication profiles. In conclusion, circulating EPC numbers could be a potential predictor of the therapeutic effect of riociguat in CTEPH patients.

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.

Effect of subclavian vein diameter combined with perioperative fluid therapy on preventing post-induction hypotension in patients with ASA status I or II

BackgroundPerioperative hypotension is frequently observed following the initiation of general anesthesia administration, often associated with adverse outcomes. This study assessed the effect of subclavian vein (SCV) diameter combined with perioperative fluid therapy on preventing post-induction hypotension (PIH) in patients with lower ASA status.MethodsThis two-part study included patients aged 18 to 65 years, classified as ASA physical status I or II, and scheduled for elective surgery. The first part (Part I) included 146 adult patients, where maximum SCV diameter (dSCVmax), minimum SCV diameter (dSCVmin), SCV collapsibility index (SCVCI) and SCV variability (SCVvariability) assessed using ultrasound. PIH was determined by reduction in mean arterial pressure (MAP) exceeding 30% from baseline measurement or any instance of MAP < falling below 65 mmHg for ≥ a duration of at least 1 min during the period from induction to 10 min after intubation. Receiver Operating Characteristic (ROC) curve analysis was employed to determine the predictive values of subclavian vein diameter and other relevant parameters. The second part comprised 124 adult patients, where patients with SCV diameter above the optimal cutoff value, as determined in Part I study, received 6 ml/kg of colloid solution within 20 min before induction. The study evaluated the impact of subclavian vein diameter combined with perioperative fluid therapy by comparing the observed incidence of PIH after induction of anesthesia.ResultsThe areas under the curves (with 95% confidence intervals) for SCVCI and SCVvariability were both 0.819 (0.744–0.893). The optimal cutoff values were determined to be 45.4% and 14.7% (with sensitivity of 76.1% and specificity of 86.7%), respectively. Logistic regression analysis, after adjusting for confounding factors, demonstrated that both SCVCI and SCVvariability were significant predictors of PIH. A threshold of 45.4% for SCVCI was chosen as the grouping criterion. The incidence of PIH in patients receiving fluid therapy was significantly lower in the SCVCI ≥ 45.4% group compared to the SCVCI < 45.4% group.ConclusionsBoth SCVCI and SCVvariability are noninvasive parameters capable of predicting PIH, and their combination with perioperative fluid therapy can reduce the incidence of PIH.

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.

Effect of needling at an acupuncture point zusanli (ST-36) on blood pressure and heart rate variability in patients with hypertension: A randomized placebo-controlled study

BackgroundAcupuncture is a traditional healing system used to prevent and treat hypertension in many countries. Acupuncture point “Zusanli (ST-36)” is used to nourish blood and yin. However, no known studies reported the effect of needling at only ST-36 on cardiovascular parameters. ObjectivesThis study was performed to find the effectiveness of ST-36 on blood pressure (BP) and heart rate variability (HRV) in patients with hypertension. MethodsA total of 100 participants with primary hypertension aged between 30 years and70 years were randomly assigned into either acupuncture group (AG) or control group (CG). AG underwent only one session of bilateral needling at ST-36 acupuncture point for duration of 20 minutes, while the CG underwent only one session of bilateral needling at non-acupuncture point for the same duration. ResultsResults of the study showed a significant reduction in systolic blood pressure, pulse pressure and mean arterial pressure in the AG compared to the CG. In addition, a significant increase in intervals between adjacent QRS complexes (R-R interval), and a significant reduction in heart rate were observed in AG, unlike CG. ConclusionsNeedling at ST-36 acupuncture point may improve cardiovascular function better than needling at non-acupuncture points in patients with hypertension.

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).

Is Tirzepatide the New Game Changer in Type 2 Diabetes?

Background: Tirzepatide (TZP) is a once-weekly glucagon-like peptide 1 (GLP-1) and glucose-dependent-insulinotropic-polypeptide (GIP) receptor co-agonist approved for T2D. TZP provides promising evidence in improving glucose control and weight loss in T2D and obesity across preclinical and human studies, including data from the SURPASS program. Aims: The goal of this paper was to review the evidence on TZP in terms of glucose control, body weight, and the progression of chronic diabetes-related complications and comorbidities. Results: The mean change in HbA1c ranged from −1.6% to −2.06% over placebo, from −0.29% to −0.92% over each GLP-1RAs, and from −0.7% to −1.09% over basal insulins. In SURPASS-6, TZP was more effective than insulin lispro U100 added to basal insulin in reducing HbA1c levels at the study end (−2.1% vs. −1.1%, respectively). Compared to placebo, TZP induces a significant weight loss: 7.5 (5 mg/week); 11 (10 mg/week); and 12 kg (15 mg/week). Compared to GLP-1RAs, TZP reduces body weight from −1.68 kg to −7.16 kg depending on the dose (5 to 15 mg, respectively). Compared to basal insulin alone rigorously titrated, TZP added onto basal-insulin results in the best strategy for the composite endpoint of improvement of glucose control and weight loss. In SURPASS-6, TZP compared to insulin lispro U100 in add-on to insulin glargine U100 reduced body weight by 9 kg in mean (versus weight gain in basal-bolus users: +3.2 kg). TZP has pleiotropic effects potentially dampening the individual cardiovascular risk, including a reduction in systolic arterial pressure by 4 to 6 mmHg and total cholesterol by 4–6% compared to baseline. A post hoc analysis of SURPASS-4 revealed that TZP, compared to glargine U100, delayed the rate of glomerular filtration decline (−1.4 mL/min vs. −3.6 mL/min, respectively), reduced the rate of urinary albumin excretion (−6.8% vs. +36.9%, respectively), and was associated with a lower occurrence of the composite renal endpoint (HR 0.58 [0.43; 0.80]). Conclusions: Consistent evidence indicates that TZP dramatically changes the clinical course of T2D in different clinical scenarios. The efficacy and safety of TZP on chronic diabetes-related comorbidities and complications seem promising, but ongoing trials will clarify the real benefits.

Impact of rapid sequential combination therapy on distinct haemodynamic measures in newly diagnosed pulmonary arterial hypertension.

In pulmonary arterial hypertension (PAH), upfront combination therapy with ERA and PDE5i is associated with a reduction in morbidity and mortality events and improves standard haemodynamics, but data remain limited. Aims of this study were (i) to capture detailed haemodynamic effects of rapid sequential dual combination therapy in patients with newly diagnosed PAH; (ii) to monitor the impact of treatment initiation on clinical variables and patients' risk status, and (iii) to compare the treatment effect in patients with 'classical PAH' and 'PAH with co-morbidities'. Fifty patients (median age 57 [42-71] years, 66% female) with newly diagnosed PAH (76% idiopathic) were treated with a PD5i/sGC-S or ERA, followed by addition of the respective other drug class within 4weeks. All patients underwent repeat right heart catheterization (RHC) during early follow-up. At early repeat RHC (7±2months), there were substantial reductions in mean pulmonary artery pressure (mPAP: 52.2±13.5 to 39.0±10.6mmHg; -25.3%), and pulmonary vascular resistance (PVR: 12.1±5.7 to 5.8±3.1 WU; -52.1%), and an increase in cardiac index (2.1±0.4 to 2.7±0.7mL/min/m2; +32.2%) (all P<0.05). Haemodynamic improvements correlated with improved clinical parameters including 6-min walking distance (336±315 to 389±120m), NTproBNP levels (1.712±2.024 to 506±550ng/L, both P<0.05) and WHO-FC at 12months, resulting in improved risk status, and were found in patients with few (n=37) or multiple cardiovascular co-morbidities (BMI>30kg/m2, hypertension, diabetes, coronary artery disease [≥3]; n=13), albeit baseline PVR in PAH patients with multiple co-morbidities was lower (9.3±4.4 vs. 13.1±5.9 WU) and PVR reduction less pronounced compared with those with few co-morbidities (-42.7% vs. -54.7%). However, comprehensive haemodynamic assessment considering further variables of prognostic relevance such as stroke volume index and pulmonary artery compliance showed similar improvements among the two groups (SVI: +50.0% vs. +49.2%; PAC: 91.7% vs. 100.0%). Finally, the 4-strata risk assessment approach was better able to capture treatment response as compared with other approaches, particularly in patients with co-morbidities. Rapid sequential combination therapy with PDE5i/sGC-S and ERA substantially ameliorates cardiopulmonary haemodynamics at early follow-up in patients without, and to a lesser extent, with cardiovascular co-morbidities. This occurs in line with improvements of clinical parameters and risk status.

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.

Comparison of nebulized ropivacaine (0.75%) with nebulized dexmedetomidine on the hemodynamic response on intubation in patients undergoing surgery under general anesthesia: A comparative randomized double-blind placebo-controlled study.

Laryngoscopy and tracheal intubation lead to sympathetic stimulation resulting in hemodynamic fluctuations. We compared local anesthetic ropivacaine 0.75% with alpha agonist dexmedetomidine through ultrasonic nebulization for direct local action of the drug in the airway. In our randomized study, 180 patients were prospectively assigned to three groups of 60 each: group R (0.75%), group D (1 microgram/kg), and group C (control). The primary objective was to determine whether nebulized ropivacaine or nebulized dexmedetomidine can cause a reduction in stress response to laryngoscopy and intubation. The secondary objectives were to compare the hemodynamic parameters at extubation, cough response at extubation, and postoperative sore throat. A total of 165 patients were analyzed. Demographically, all the groups were similar. Group R and group D were found to significantly attenuate the heart rate (HR) at intubation and extubation when compared to group C (P < 0.05). A significant reduction in mean arterial pressure (MAP) was seen (P < 0.05; group D: 90 ± 18.4 mmHg, group C: 99.5 ± 15.9 mmHg, group R: 92.4 ± 16.1 mmHg). There was a significant reduction in cough response in both groups in comparison with group C at 0 minutes (P value; group C vs group D: <.0001; group C vs group R:.01) and 5 minutes (P value; group C vs group D: <.0001; group C vs group R: <.0001). Preinduction topical use of ropivacaine or dexmedetomidine, through the nebulization route, effectively attenuated the pressor responses when compared to placebo.