Measured Mean Arterial Pressure Research Articles

Ringer’s lactate administered at 15 °C leads to a greater and more prolonged increase in blood pressure compared to 37 °C

18 Participants were randomized to receive 30 ml/kg bodyweight Ringer’s Lactate at 37° or 15 °C over 30 min. In a second session, participants were crossed over. Over a 120 min period after starting the fluid bolus we measured mean arterial pressure (MAP), cardiac output, systemic vascular resistance, and catecholamine levels. After infusion with cold fluids, the absolute increase in MAP at 45 min was significantly higher at + 6.5 mmHg (95% CI 4.8–8.2) compared with warm fluids (+ 0.6 mmHg, 95% CI, − 1.6 to 2.8; p < 0.001). This increase in MAP was longer-lasting after cold fluids (81.7 min, 95% CI 62.5–100.9) than after warm fluids (19.2, 95% CI 3.4–35; p < 0.001). While cardiac output was similar, systemic vascular resistance increase was greater after cold fluids (159 dyn s/cm5, 95% CI 9.5–309) compared to warm fluids (− 66 dyn s/cm5, 95% CI − 191 to 57; p = 0.012). Moreover, noradrenaline increased by up to 246% during cold fluids, and decreased with warm fluids (p < 0.001). Fluid bolus given at 15 °C, compared to 37 °C, leads to a greater and more prolonged increase in MAP accompanied by release of intrinsic noradrenaline and vasoconstriction. These results suggest that fluid temperature rather than volume is predominantly responsible for any increase in MAP.Trial Registration: EudraCT-nummer 2022-002137-34 and clinicaltrials.gov NCT05610254 (first registration 09/11/2022).

Dexmedetomidine-propofol versus ketamine-propofol for sedation of cancer patients undergoing computerized tomography guided bone biopsy: a randomized double-blind trial

Background &amp; Objective: Patients suffering from malignancy, often need to undergo computed tomography (CT) for evaluation or for CT-guided bone biopsy. They are shifted to the radio-diagnostic suite and require sedation and analgesia during this procedure. We compared the efficacy and safety of combining dexmedetomidine (DEX) or ketamine with propofol for better sedation among these patients undergoing CT-guided bone biopsy. Methodology: This randomized, double-blind study was done on 60 adult cancer patients undergoing CT-guided bone biopsy. Patients were randomized into two equal groups. Group D received DEX 1 µg/kg (over 10 min) + propofol 2.5 mg/kg intravenous (IV). It was followed by DEX 0.5 µg/kg/h + propofol 2.5 mg/kg/h infusion. Group K received ketamine 1 mg/kg + propofol 2.5 mg/kg IV, followed by ketamine 0.25 mg/kg/h + propofol 2.5 mg/kg/h infusion. Results: The total intra-procedure propofol consumption was significantly decreased in Group D than in Group K (P &lt; 0.05). The visual analog scale score at 15 min and 30 min post-procedure, number of patients requiring morphine and paracetamol within one hour of procedure and the recovery times were significantly decreased in Group D than in Group K (P &lt; 0.05). Mean arterial pressure (MAP) and heart rate (HR) measurements at 10 min, 20 min, end of the procedure, and 15 min, 30 min post-procedure was significantly decreased in Group D than in Group K (P &lt; 0.05). Adverse events, e.g., postoperative nausea and vomiting, hypotension, and bradycardia, were comparable. Conclusion: DEX-propofol combination had superior sedation efficacy as noted through lower pain scores, intraprocedural propofol or postprocedural morphine and paracetamol consumption, and the shorter recovery time during CT-guided bone biopsy compared to ketamine-propofol combination. However, ketamine-propofol combination exhibited superior hemodynamic stability, as shown by more consistent HR and MAP. Keywords: Dexmedetomidine; Ketamine; Propofol; Computed tomography; Bone biopsy; Morphine Citation: Abdelgalil AS, Mohammed AM, Abdelrahman AS, Zayed NOA. Dexmedetomidine-propofol versus ketamine-propofol for sedation of cancer patients undergoing computerized tomography guided bone biopsy: a randomized double-blind trial. Anaesth. pain intensive care 2024;28(5):809−815; DOI: 10.35975/apic.v28i5.2554 Received: Jun 17, 2024; Reviewed: Jul 31, 2024; Accepted: Aug 19, 2024

Effect of Dietary Enrichment with Hempseed (Cannabis sativa L.) on Blood Pressure Changes in Growing Mice between Ages of 5 and 30 Weeks

Dietary hempseed (Cannabis sativa L.) reduces blood pressure in adults and animal models of hypertension; however, whether hempseed consumption throughout early life reduces adult blood pressure is not known. This study tested the hypothesis that hempseed enrichment versus a control diet modifies the age-dependent pattern of blood pressure changes in growing female C57BL/6 mice and results in lower adult blood pressure. From ages 5 to 30 weeks, early post-weaning to mid-adulthood, mice were fed either a control AIN-93G (0%), 50 g/kg (5%), or 150 g/kg (15%) hempseed-supplemented diet (n = 8 per group). Biweekly measurements of systolic, diastolic, and mean arterial pressure were collected using the tail-cuff method. Mice fed 5% or 15% hempseed versus the control diet exhibited no significant differences in systolic, diastolic, or mean arterial blood pressure (repeated measures ANOVA main effect of diet, p &gt; 0.05). Blood pressure did not differ significantly between diet groups in adulthood (p &gt; 0.05). However, mice fed a control or 5% hempseed, but not 15% hempseed, diet exhibited blood pressure changes across age marked by significant increases during early adulthood (weeks 11–17) versus early post-weaning (week 5) (p &lt; 0.05). In conclusion, long-term dietary hempseed enrichment at 5% and 15% concentrations during development does not reduce adult blood pressure, but a 15% dose blunts the temporary increase in blood pressure during early adulthood seen in mice fed a control diet.

Abstract 54: The kidney-OVLT axis in renovascular hypertension: Individual and combined effects of afferent renal denervation and OVLT lesion in 2K1C rats.

We have recently reported that afferent renal denervation (ARDN) markedly attenuates the pathogenesis of hypertension in the 2 kidney 1 clip (2K1C) model in the rat. This was associated with a reduction in neurogenic pressor activity (NPA). We have also recently shown that lesion of the organum vasculosum of the lamina terminalis (OVLT), a forebrain circumventricular organ, had nearly identical effects in 2K1C rats as ARDN. Together these findings suggest that a neural pathway from the kidney to the OVLT plays an important role in 2K1C hypertension. Based on these findings we hypothesized that the combined effect of ARDN and lesion of the OVLT (OVLTx) on arterial pressure in 2K1C rats would not be greater than the individual treatments. Male Sprague-Dawley rats were randomly selected to receive either OVLT lesion (x) or sham-OVLTx. One week later, rats were instrumented with telemeters to measure mean arterial pressure (MAP). One week later, renal artery stenosis was created by placing a clip on the left renal artery and then, rats were subjected to ARDN by periaxonal capsaicin or sham treatment of the clipped kidney creating 4 experimental groups: sham+sham (n=6), sham+ARDN (n=6), OVLTx+sham (n=5), OVLTx+ARDN (n=5). MAP was measured daily for 28 days, and at the end of the protocol, NPA was assessed by measuring the peak MAP response to ganglionic blockade. MAP was similar in all 4 groups at the beginning of the study averaging 108±3 mmHg. MAP increased to 180±10 mmHg in the sham+sham group compared to 130±13mmHg in sham+ARDN, 142±18mmHg in OVLTx+sham rats and 158±14mmHg in OVLTx+ARDN rats (p&lt;0.001). NPA in Sham+sham rats was significantly higher (-44 ± 8 mmHg) compared to sham+ARDN (-18 ± 3 mmHg), OVLTx+sham (-21 ± 2 mmHg) and OVLTx+ARDN (-19 ± 4 mmHg) rats (p&lt;0.05). Notably, the combined effects of OVLTx+ARDN on MAP and NPA were not significantly different from either OVLTx (p=1.00 and p=0.819) or ARDN (p=0.113 and p= 0.878) alone. In summary, ARDN and OVLTx attenuated hypertension and NPA similarly in 2K1C-HTN rats but the combination of these treatments did not produce any additional effect on MAP or NPA. These findings are consistent with the hypothesis that afferent renal nerves and the OVLT are linked in a common neural pathway required for the development of hypertension following renal artery stenosis.

Abstract P212: Microinjection of the novel angiotensin, alamandine-(1-5) into insular cortex, increase blood pressure

It is well known that the renin-angiotensin system plays a critical role in cardiovascular control and hydro-electrolyte homeostasis. At least in some circumstances Alamandine (Ala) and Angiotensin-(1-7) can have selective actions such as reported in the insular córtex (IC). Hydrolysis of Angiotensin-(1-7) by angiotensin converting enzyme (ACE) can form the heptapeptide Angiotensin-(1-5) and recently our group demonstrated that hydrolysis of Ala by ACE can form Ala-(1-5). In this study we aimed to evaluate the cardiovascular effects produced by microinjection of Ala-(1-5) and Angiotensin-(1-5) into the rostral region of the posterior IC. Urethane (1.4g/kg) anesthetized rats were instrumented for measurement of mean arterial pressure (MAP), heart rate (HR) and renal sympathetic nerve activity (RSNA). Unilateral microinjection of vehicle (0,9% NaCl, 100nL, n=4), Ala (40pmol/100nl, n=7), Ala-(1-5) (400pmol/100nl, n=7) or Angiotensin-(1-5) (400pmol/100nl, n=5) were made into IC (+1.5mm rostral to the bregma). At the baseline, there was no difference between the groups (Vehicle: 85±2 mmHg and 388±5bpm, Ala: 83±9mmHg and 389±10bpm, Ala-(1–5): 91±6mmHg and 386±7bpm or Ang-(1-5): 96±9mmHg and 375±6bpm). Vehicle microinjection was performed as a control for nonspecific effects (ΔMAP:2±1mmHg, ΔHR:4±2bpm, ΔRSNA:3±1%). Ala microinjection into IC, confirmed our previous data showing a long-lasting (18±3min) increase in MAP (Δ=14±2mmHg), and this effect was associated with a significant increase in HR (Δ=32±4bpm) and in RSNA (Δ=36±6%). These responses were elicited immediately after Ala microinjection. When compared with vehicle and, very different from what was observed with Ala, microinjection of Ala-(1–5) evoked a significant increase in blood pressure without altering RSNA or HR (ΔMAP:22±2mmHg, ΔHR:-1±3bpm, ΔRSNA:1±3%). Differently from Ala evoked responses, the effects of Ala-(1–5) had a shorter duration (5.88±1.9min) without delay to beginning the effects. On other hand, microinjection of Angiotensin-(1-5) did not elicited autonomic and cardiovascular effects (ΔMAP:-1±3mmHg, ΔHR:-2±2bpm, ΔRSNA:2±3%). In conclusion, these data showed that the IC is a brain site that has unique effects of Ala (increase in MAP, HR and RSNA) and Ala-(1-5) (increase in MAP only) contrasting with the essentially absent effects of Angiotensin-(1-7) and Angiotensin-(1-5). These findings will contribute to extend our understanding of the brain renin-angiotensin system.

Abstract P452: Cell Populations and Transcriptomes Differ Across Blood Pressure and Sex in Perivascular Adipose Tissue: A Single-Nuclei RNA Sequencing Study

The perivascular adipose tissue (PVAT), fat that surrounds many blood vessels, is capable of modulating vascular tone through multiple modalities. Despite increasing research interest, PVAT remains less understood compared to other vascular layers. We hypothesized that the transcriptome and cell population of thoracic aorta PVAT (taPVAT) differ between hypertensive and normotensive rats. To test this hypothesis, we performed single-nucleus RNA-sequencing (snRNA-seq) on twenty-five taPVAT samples from male and female Dahl SS rats, fed either control (Con) chow or a high-fat diet (HFD) for 8 or 24 weeks. Mean arterial pressure (MAP) measurements showed elevated values in female rats fed a HFD for 24 weeks with a trend towards increasing blood pressure in male rats (Fig. 1a). Our analysis included at least three taPVAT samples per treatment group, resulting in 71,813 high-quality sequenced nuclei, representing eight major cell types (Fig. 1b) and twenty-eight cell sub-types. Within each cell type, the differences in population and gene expression across diet, diet duration, and sex were examined. The most substantial population proportion differences were observed across diet duration, with fewer differences noted across diet and sex (Fig. 1c). The total number of differentially expressed genes (DEGs) (adjusted p-value ≤ 0.05, |log 2 (fold change)| ≥ 1) across diet, diet duration, and sex were 191, 424, and 119, respectively. Interestingly, in the taPVAT from HFD fed rats, the gene Csmd1 (CUB and Sushi multiple domains 1) was consistently upregulated across nearly all cell types. Whereas Scd (stearoyl-CoA desaturase), which is involved in fatty acid biosynthesis, was frequently the most downregulated gene. Pathway enrichment analysis revealed that the DEGs related to the HFD were associated with a decrease in lipid and fatty acid biosynthetic processes. DEGs related to rats fed a HFD for twenty-four weeks versus eight weeks were linked to an enrichment in inflammatory response and extracellular matrix organization pathways, and in HFD fed male rats compared to females, there was enrichment for leukocyte aggregation and peptidyl-cysteine modification pathways. In conclusion, our findings help paint a more detailed picture of the molecular and cellular changes in taPVAT associated with hypertension.

Abstract P191: Progesterone Supplementation Ameliorates the Maternal Syndrome of Preeclampsia in the Dahl Salt-Sensitive Rats

Introduction: Preeclampsia (PreE) is characterized by new onset hypertension after 20 weeks of gestation. PreE is associated with activated CD4+ T cells, inflammation, autoantibodies to angiotensin II type 1 receptor (AT1-AA) and hypertension. To date, the best treatment remains early delivery of the feto-placental unit. Hypothesis: This study was designed to test the hypothesis that progesterone, in the form of 17-hydroxyprogesterone caproate (17-OHPC), reduces inflammation and blood pressure in the Dahl Salt-Sensitive (Dahl S) rat model of PreE. Methods: A subset of pregnant Sprague-Dawley (SD) and Dahl S rats were injected with 17-OHPC (3.32mg/kg, human dose equivalent) or vehicle (saline) at day 15 (GD15) of gestation. On GD 18, Uterine Artery Resistance Index (UARI) was measured by Doppler Ultrasound and carotid catheters were inserted for mean arterial blood pressure (MAP) measurement on GD19. Circulating and placental populations of CD4+ T cells were quantified by flow cytometry. TNF-alpha and IL-6 were measured by ELISA and AT1-AA were quantified by the chronotropic responses to angiotensin II type 1 receptor-mediated stimulation of cultured neonatal rat cardiomyocytes. Results are reported as means ± standard error means (SEM) and statistically significant when p &lt; 0.05. Results: MAP was 105±5 mmHg in SD+ vehicle rats (n=6), 104±4 in SD+17-OHPC rats (n=6), 136±3 in Dahl S+ saline rats (p &lt;0.05, n=11), which improved to 125±4 in DS+17-OHPC rats (p &lt;0.05, n=7). Pup and Placenta weights were 2.1± 0.1, 0.6 ± 0.1 g in SD+ vehicle rats and reduced to 1.4±0.1 (p&lt;0.05), 0.5±0.1 g in Dahl S +vehicle. UARI was 0.5 ±0.1 in SD+ vehicle rats (n=6) and 0.5 ±0.1 in in SD+17-OHPC (n=6), 0.7±0.1 in Dahl S+ vehicle rats (n=6, p&lt;0.05), which reduced to 0.5±0.1 in Dahl S+17-OHPC (n=7, p&lt;0.05). TNF-alpha and IL-6 levels (n=4-5/group) were 3.0±1.0, 45±11 pg/mL in SD+ vehicle rats, 11.0±1.2, 78±21 in Dahl S+ vehicle rats, which reduced to 4.1±1.6 (p&lt;0.05), 62±12 in Dahl S+17-OHPC. Circulating and placental CD4+ T cells were 9.3±3.7 %, 6.4± 1.6 % gate in SD+ vehicle rats (n=4), 38.9 ±2.9, 33.1±4.3 % gate Dahl S+ Saline rats (n=6), which significantly reduced to 26.3 ± 0.1 %, 3.4±1.2 % gate in DahlS+17-OHPC. AT1-AA were -1 ± 2 ΔBPM (beats per minute) in SD+ vehicle rats, 4 ± 1 in Dahl S+ Saline rats and -0.6±2 Dahl S+17-OHPC rats (n=5, p&lt;0.05). Conclusion: Our findings demonstrate that 17-OHPC ameliorates the maternal syndrome in the Dahl Salt-Sensitive rat model of PreE.

Blocking TSP1 Ameliorates Diabetes Mellitus-Induced Erectile Dysfunction by Inhibiting the TGF-β/SMAD Pathway.

To examine the role and mechanism of thrombospondin-1 (TSP1) in the development of fibrosis in diabetes mellitus-induced erectile dysfunction (DMED). DMED was induced by intraperitoneal streptozotocin injection. All rats were categorized into three groups: control group (n=8), DMED group (n=8) and DMED+Leu-Ser-Lys-Leu (LSKL) group (n=8). After eight weeks following the induction of diabetes mellitus, the DMED+LSKL group was subjected to intraperitoneal injections of LSKL twice weekly for four weeks. To measure intracavernous pressure (ICP), a 25-gauge needle connected to a PE tube containing heparin was inserted into the corpus cavernosum (CC). Additionally, a needle was inserted into the carotid artery to measure mean arterial pressure (MAP). Sirius red staining and Masson trichrome staining were utilized to assess CC fibrosis. Moreover, high glucose (HG)-induced CC smooth muscle cells (CCSMCs) and CC fibroblasts (CCFs) were treated with or without LSKL. Western blotting and immunofluorescence were utilized to assess the phosphorylation and expression of related proteins. Compared with those in the control group, the ratio of the maximum ICP to the MAP markedly decreased in the DMED group, as did the ratio of smooth muscle to collagen and the ratio of collagen I to collagen III. These ratios were greater in the DMED+LSKL group than in the DMED group. TSP1 was highly expressed in the CC of DMED rats. In vitro experiments indicated that TSP1 expression significantly increased in the medium of CCSMCs and CCFs cultured in HG media and that the TGF-β pathway was activated in CCSMCs. Collagen IV was overexpressed in CCSMCs, indicating severe fibrosis was severe. Adding LSKL or knocking TSP1 down can prevent the activation of TGF-β signaling, as well as the overexpression of collagen IV in CCSMCs promoted by TSP1 secreted from CCSMCs itself or CCFs. TSP1 expression is increased in the CC of DMED rats. HG-induced TSP1 secretion via autocrine signaling from CCSMCs and/or paracrine signaling from CCFs to accelerate penile fibrosis. LSKL, an antagonist of TSP1, could improve erectile dysfunction by inhibiting the TGF-β/SMAD pathway.

Evidence that systemic vascular resistance is increased before the development of gestational diabetes mellitus

The ophthalmic artery, which is the first branch of the internal carotid artery, has a Doppler velocity waveform with two systolic peaks. The ratio of the peak systolic velocity (PSV) of the second wave divided by that of the first wave, reflects increased peripheral resistance. Previous studies in the first, second and third trimesters of pregnancy have reported that in pregnancies that subsequently develop preeclampsia (PE) the PSV ratio is increased. Both PE and gestational diabetes mellitus (GDM) are associated with endothelial dysfunction and an increased risk of cardiovascular diseases during the first decade following pregnancy. To compare the ophthalmic artery PSV ratio at 11-13 weeks' gestation in women who subsequently develop GDM to unaffected pregnancies and those who develop PE. This was a prospective observational study in women attending for a routine hospital visit at 11+0 - 13+6 weeks' gestation at King's College Hospital, London, UK. This visit included recording of maternal demographic characteristics and medical history, ultrasound examination for fetal anatomy and growth, assessment of flow velocity waveforms from the maternal ophthalmic arteries and calculation of the PSV ratio, and measurement of mean arterial pressure (MAP). Linear regression was performed for the prediction of ophthalmic artery PSV ratio, from maternal characteristics and MAP. The PSV ratio in the group with GDM was compared to that of PE and unaffected pregnancies. 3999 women were included in the study, including 375 (9.8%) who developed GDM and 101 (2.5%) who developed PE. In the GDM group, 161 (43.3%) were treated by diet alone, 130 (34,1%) were treated with metformin and 84 (22.6%) received insulin ± metformin. Significant prediction of PSV ratio was provided by development of PE, maternal age, body mass index, MAP, first degree family history of diabetes mellitus, family history of PE, Asian ethnicity, and smoking. There was no significant contribution from GDM. In women who developed GDM requiring insulin treatment, ophthalmic artery PSV ratio (0.67 ± 0.09) was higher (p <0.001) than in unaffected pregnancies (0.63 ± 0.10), but it was not significantly different from that in the PE group (0.69 ± 0.10; p=0.90). In women who develop severe GDM, requiring insulin treatment, there is evidence of increased peripheral resistance which is apparent from the first-trimester of pregnancy.

The potential of repeated mean arterial pressure measurements for predicting early- and late-onset pre-eclampsia in twin pregnancies: Prediction model study.

To investigate the contribution of longitudinal mean arterial pressure (MAP) measurement during the first, second, and third trimesters of twin pregnancies to the prediction of pre-eclampsia. A retrospective cohort study was conducted on women with twin pregnancies. Historical data between 2019 and 2021 were analyzed, including maternal characteristics and mean artery pressure measurements were obtained at 11-13, 22-24, and 28-33 weeks of gestation. The outcome measures included pre-eclampsia with delivery <34 and ≥34 weeks of gestation. Models were developed using logistic regression, and predictive performance was evaluated using the area under the curve, detection rate at a given false-positive rate of 10%, and calibration plots. Internal validation was conducted via bootstrapping. A total of 943 twin pregnancies, including 36 (3.82%) women who experienced early-onset pre-eclampsia and 93 (9.86%) who developed late-onset pre-eclampsia, were included in this study. To forecast pre-eclampsia during the third trimester, the most accurate prediction for early-onset pre-eclampsia resulted from a combination of maternal factors and MAP measured during this trimester. The optimal predictive model for late-onset pre-eclampsia includes maternal factors and MAP data collected during the second and third trimesters. The areas under the curve were 0.937 (95% confidence interval [CI] 0.894-0.981) and 0.887 (95% CI 0.852-0.921), respectively. The corresponding detection rates were 83.33% (95% CI 66.53%-93.04%) for early-onset pre-eclampsia and 68.82% (95% CI 58.26%-77.80%) for late-onset pre-eclampsia. Repeated measurements of MAP during pregnancy significantly improved the accuracy of late-onset pre-eclampsia prediction in twin pregnancies. The integration of longitudinal data into pre-eclampsia screening may be an effective and valuable strategy.

Maternal cardiovascular function in midgestation is related to placental angiogenesis.

To investigate whether angiogenic markers of placental function are associated with maternal cardiac function and hemodynamic responses at 19-23 weeks' gestation, controlling for maternal risk factors and pregnancy complications. This was a prospective study of women with singleton pregnancy attending King's College Hospital, London, UK, for a routine hospital visit at 19-23 weeks' gestation. We recorded maternal characteristics and measured mean arterial pressure (MAP), maternal heart rate, serum placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFlt-1). We also performed maternal echocardiography to assess cardiac output and peripheral vascular resistance as well as indices of diastolic and systolic function. Our cohort included 4006 women. Lower PlGF values were significantly associated with higher MAP (P < 0.0001), lower maternal heart rate (P < 0.0001), lower mitral valve s' mean velocity (P = 0.027) and higher left atrial area (P = 0.022) after adjustment for maternal characteristics and pregnancy complications. sFlt-1 was associated positively with relative wall thickness (P = 0.012), whereas sFlt-1/PlGF ratio was associated negatively with mitral valve A (P = 0.006) and positively with left atrial area (P = 0.015) and MAP (P = 0.004). The magnitude of these associations was similar in the subgroup of women without any risk factors based on their obstetric and medical history. A continuous association of moderate strength between angiogenic factors and subclinical maternal cardiac function alterations is present in midgestation, independently of pre-existing maternal risk factors and pregnancy complications. Impaired placental function appears to be related to mild systolic and diastolic dysfunction and cardiac remodeling. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

Dexmedetomidine Moderate Sedation Versus General Anesthesia on the Diagnostic Yield of Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration: A Randomized Controlled Study.

One of the factors that affect the diagnostic yield of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is the level of sedation. Therefore, we aimed to compare dexmedetomidine (DEX) as moderate sedation (MS) versus general anesthesia (GA) on the diagnostic yield of EBUS-TBNA. This randomized open-label controlled trial was carried out on 70 patients older than 18 years of age, classified as American Society of Anesthesiologists (ASA) II or III, and scheduled for EBUS-TBNA. Patients were randomly allocated into two equal groups. Group D received 1 μg/kg fentanyl 2 minutes before induction with a 1 μg/kg infusion of DEX for 10 minutes, then maintenance with 0.5 - 1 μg/kg/h aiming for a Ramsey Sedation Scale of 4 - 5 while preserving hemodynamics. Group GA received 1 μg/kg fentanyl, 2 mg/kg propofol, and 0.5 mg/kg atracurium (then 0.1 mg/kg every 20 minutes). Group D had a significantly higher rate of recalling the procedure (P = 0.005) and a lower rate of shortness of breath compared to group GA (P = 0.038). Intraoperative heart rate measurements at baseline were not significantly different between groups but were significantly lower at 5 min, 10 min, 15 min, 20 min, and at the end of surgery in group D compared to group GA (P < 0.05). Intraoperative mean arterial blood pressure measurements at baseline, 5 min, 10 min, 15 min, 20 min, and at the end of surgery were not significantly different between groups. Recovery time was significantly shorter in group D compared to group GA (P < 0.001). Compared to GA, MS with DEX showed a comparable diagnostic yield with faster recovery time and better patient satisfaction, as evidenced by a willingness to repeat procedures when needed and less shortness of breath in EBUS-TBNA.

Effects of sodium-glucose transporter-2 inhibition on systemic hemodynamics, renal function, and intra-renal oxygenation in sepsis-associated acute kidney injury

BackgroundPeople with type 2 diabetes mellitus treated with sodium-glucose transporter-2 inhibitors (SGLT2i) have lower rates of acute kidney injury (AKI). Sepsis is responsible for the majority of AKI in critically ill patients. This study investigated whether SGLT2i is renoprotective in an ovine model of Gram-negative septic AKI.MethodsSixteen healthy merino ewes were surgically instrumented to enable measurement of mean arterial pressure, cardiac output, renal blood flow, renal cortical and medullary perfusion, and oxygenation. After a 5-day recovery period, sepsis was induced via slow and continuous intravenous infusion of live Escherichia coli. Twenty-three hours later, sheep were randomized to receive an intravenous bolus of 0.2 mg/kg empagliflozin (n = 8) or a fluid-matched vehicle (n = 8).ResultsEmpagliflozin treatment did not significantly reduce renal medullary hypoperfusion or hypoxia, improve kidney function, or induce histological changes. Renal cortical oxygenation during the intervention period was 47.6 ± 5.9 mmHg in the empagliflozin group compared with 40.6 ± 8.2 mmHg in the placebo group (P = 0.16). Renal medullary oxygenation was 28.0 ± 18.5 mmHg in the empagliflozin compared with 25.7 ± 16.3 mmHg (P = 0.82). Empagliflozin treatment did not result in significant between-group differences in renal blood flow, kidney function, or renal histopathological changes.ConclusionIn a large mammalian model of septic AKI, a single dose of empagliflozin did not improve renal microcirculatory perfusion, oxygenation, kidney function, or histopathology.

Evaluation of lingual oscillometric blood pressure measurement in anaesthetized pigs

ObjectiveTo evaluate the agreement between measurements of invasive blood pressure (IBP) and oscillometric blood pressure from the tongue (OBPton) using a multiparameter monitor. Study designUnblinded, prospective, experimental study. AnimalsA total of 12 female Large White crossbreed pigs. MethodsPigs undergoing experimental procedures that required arterial cannula placement were recruited. A blood pressure cuff with the closest width to 40% of the circumference of the tongue was placed rostral to the lingual frenulum. Systolic, mean and diastolic IBP and OBPton were measured simultaneously at 5 minute intervals. Agreement between paired measurements was examined using Bland–Altman analysis. Mean bias, precision (standard deviation of mean bias), 95% limits of agreement, correlation coefficients and percentage of measurements within 10 and 20 mmHg of IBP were calculated. ResultsThe total numbers of paired measurements recorded were 124, 126 and 124 for systolic, mean and diastolic blood pressures, respectively. The mean bias, precision and 95% limits of agreement for systolic OBPton were 11.5, 11.5 (–11.1 to 34.2), for mean OBPton 5.6, 5.7 (–5.7 to 16.8) and for diastolic OBPton 7.6, 10.1 (–12.1 to 27.4) mmHg. Correlation coefficients were greater than 0.9 for mean OBPton only. More than 50% of measurements were within 10 mmHg of IBP and 80% of measurements were within 20 mmHg of IBP for mean and diastolic OBPton only. Conclusions and clinical relevanceThe tongue as a cuff site for oscillometric blood pressure measurement is a useful site for measuring mean arterial, but not systolic or diastolic blood pressure in anaesthetized Large White crossbreed pigs. This technique fulfils the American College of Veterinary Internal Medicine criteria for measuring mean arterial pressure but not systolic or diastolic arterial pressure.

A prediction model for stillbirth based on first trimester pre-eclampsia combined screening.

To evaluate the accuracy of combined models of maternal biophysical factors, ultrasound, and biochemical markers for predicting stillbirths. A retrospective cohort study of pregnant women undergoing first-trimester pre-eclampsia screening at 11-13 gestational weeks was conducted. Maternal characteristics and history, mean arterial pressure (MAP) measurement, uterine artery pulsatility index (UtA-PI) ultrasound, maternal ophthalmic peak ratio Doppler, and placental growth factor (PlGF) serum were collected during the visit. Stillbirth was classified as placental dysfunction-related when it occurred with pre-eclampsia or birth weight <10th percentile. Combined prediction models were developed from significant variables in stillbirths, placental dysfunction-related, and controls. We used the area under the receiver-operating-characteristics curve (AUC), sensitivity, and specificity based on a specific cutoff to evaluate the model's predictive performance by measuring the capacity to distinguish between stillbirths and live births. There were 13 (0.79%) cases of stillbirth in 1643 women included in the analysis. The combination of maternal factors, MAP, UtA-PI, and PlGF, significantly contributed to the prediction of stillbirth. This model was a good predictor for all (including controls) types of stillbirth (AUC 0.879, 95% CI: 0.799-0.959, sensitivity of 99.3%, specificity of 38.5%), and an excellent predictor for placental dysfunction-related stillbirth (AUC 0.984, 95% CI: 0.960-1.000, sensitivity of 98.5, specificity of 85.7). Screening at 11-13 weeks' gestation by combining maternal factors, MAP, UtA-PI, and PlGF, can predict a high proportion of stillbirths. Our model has good accuracy for predicting stillbirths, predominantly placental dysfunction-related stillbirths.

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.

The left ventricle increases contractility in response to baroreceptor unloading, which is sympathetically mediated in the anesthetized rat.

Contemporary discussion of the baroreflex includes the efferent vascular-sympathetic and cardiovagal arms. Since sympathetic postganglionic neurons also innervate the left ventricle (LV), it is often assumed that the LV produces a sympathetically mediated increase in contractility during baroreceptor unloading, but this has not been characterized using a load-independent index of contractility. We aimed to determine 1) whether LV contractility increases in response to baroreceptor unloading and 2) whether such increases are mediated via the sympathetic or parasympathetic arm of the autonomic nervous system. Ten male Wistar rats were anesthetized (urethane) and instrumented with arterial and LV pressure-volume catheters to measure mean arterial pressure (MAP) and load-independent LV contractility [maximal rate of increase in pressure adjusted to end-diastolic volume (PAdP/dtmax)], respectively. Rats were placed in a servo-controlled lower-body negative pressure (LBNP) chamber to reduce MAP by 10% for 60 s to mechanically unload baroreceptors under control conditions. LBNP was repeated in each animal following infusions of cardiac autonomic blockers using esmolol (sympathetic), atropine (parasympathetic), and esmolol + atropine. Under control conditions, PAdP/dtmax increased during baroreceptor unloading (26 ± 6 vs. 31 ± 9 mmHg·s-1·μL-1, P = 0.031). During esmolol, there was no increase in LV contractility during baroreceptor unloading (11 ± 2 vs. 12 ± 2, P = 0.125); however, during atropine, there was an increase in LV contractility during baroreceptor unloading (26 ± 6 vs. 31 ± 9, P = 0.019). During combined esmolol and atropine, there was a small increase in contractility versus control (13 ± 3 vs. 15 ± 4, P = 0.046). Our results demonstrate that, in anesthetized rats, LV contractility increases in response to baroreceptor unloading, which is largely sympathetically mediated.NEW & NOTEWORTHY This study empirically demonstrates a sympathetically mediated increase in LV contractility in response to baroreceptor unloading using a load-independent index of cardiac contractility in the anesthetized rat.

Cerebrovascular Autoregulation in Preterm Infants Using Heart Rate or Blood Pressure: A Pilot Study.

Cerebrovascular autoregulation (CAR) is often impaired in preterm infants but requires invasive mean arterial blood pressure (MABP) measurements for continuous assessment. We aimed to assess whether using heart rate (HR) results in different CAR assessment compared with using MABP. We compared CAR (moving window correlation-coefficient with cerebral oxygenation saturation (rcSO2)), and percentage of time with impaired CAR (%timeCARi) calculated by either HR (TOHRx, tissue oxygenation heart rate reactivity index) or MABP (COx, cerebral oximetry index) during the first 72 h after birth, and its association with short-term cerebral injury. We included 32 infants, median gestational age of 25 + 5/7 weeks (interquartile range 24 + 6/7-27 + 5/7). COx and TOHRx correlation coefficients (cc) were significantly different in the first two days after birth (individual means ranging from 0.02 to 0.07 and -0.05 to 0.01). %TimeCARi using MABP (cc cut-off 0.3), was higher on day 1 (26.1% vs. 17.7%) and day 3 (23.4% vs. 16.9%) compared with HR (cc cutoff -0.3). During 65.7-69.6% of the time, both methods indicated impaired CAR simultaneously. The aforementioned calculations were not associated with early cerebral injury. In conclusion, HR and MABP do not seem interchangeable when assessing CAR in preterm infants.

Optimizing sedation in gastroscopy: a study on the etomidate/propofol mixture ratio.

Propofol and etomidate are the most commonly used sedative agents in procedural sedation, each with its own advantages and disadvantages. However, there remains considerable controversy regarding the optimal ratio for the mixture of these two drugs, warranting further investigation. Therefore, this study aims to investigate the optimal ratio for combining propofol and etomidate during gastroscopy. This study is a prospective, double-blinded, randomized controlled clinical trial. One hundred and sixty-two patients from July 2019 to December 2022 were evenly classified into three groups using a random number table as follows: (1) P group (propofol); (2) EP1 group (5 mL etomidate +10 mL propofol); (3) EP2 group (10 mL etomidate +10 mL), 54 patients per group. The medications, including a pre-sedation dose of 50 μg/kg dezocine followed by sedatives, ceasing when the patient's eyelash reflex vanished, indicating adequate sedation. Mean arterial pressure (MAP), heart rate (HR), and peripheral oxygen saturation (SpO2) measurements taken before anesthesia (T1), immediately after the administration of sedatives (T2), immediately gastroscopic insertion (T3) and immediately recovery (T4) were determined. Additional, perioperative related outcomes and adverse events were also recorded. The EP2 group exhibited a higher MAP at T2 compared to the P and EP1 groups (p < 0.05). Calculated decreases in MAP revealed values of 19.1, 18.8, and 13.8% for the P, EP1, and EP2 groups at T2, respectively. Adverse events: Group EP2 exhibited a significantly lower hypotension incidence (11.1%) compared to the Propofol group (50%) and EP1 (31.5%). Concerning injection pain, Group EP2 also showing a significant decrease in comparison to P and EP1 groups (p < 0.05). The use of a mixture of 10 mL etomidate and 10 mL propofol (at a 1:1 ratio) combined with dezocine for painless gastroscopy demonstrates hemodynamic stability, a low incidence of adverse reactions. https://www.chictr.org.cn/showproj.html?proj=39874.

Chronic inhibition of angiotensin converting enzyme lowers blood pressure in spontaneously hypertensive rats by attenuation of sympathetic tone: The role of enhanced baroreflex sensitivity

Spontaneously hypertensive rats (SHR) are characterized by sympathetic hyperactivity and insufficient parasympathetic activity, and their high blood pressure (BP) can be lowered by long-term inhibition of the renin-angiotensin system. The aim of our study was to determine the influence of chronic inhibition of angiotensin converting enzyme (ACE) by captopril on cardiovascular regulation by the sympathetic and parasympathetic nervous system. Implanted radiotelemetric probes or arterial cannulas were used to measure mean arterial pressure (MAP), heart rate (HR), and arterial baroreflex in adult SHR and Wistar-Kyoto (WKY) rats under basal or stress conditions. MAP and the low-frequency component of systolic blood pressure variability (LF-SBPV, marker of sympathetic activity) were greater in SHR than in WKY rats. Under basal conditions chronic captopril treatment reduced both parameters more effectively in SHR, and the same was true during acute restraint stress. HR was similar in control rats of both strains, but WKY rats showed greater heart rate variability (HRV), indicating higher parasympathetic activity. Captopril administration increased HR in both strains, whereas HRV was decreased only in WKY. Chronic captopril treatment improved the impaired baroreflex-HR control in SHR by increasing the sensitivity but not the capacity of vagal arm of arterial baroreflex. Captopril treatment attenuated BP changes elicited by dimethylphenylpiperazinium (DMPP, agonist of nicotinic acetylcholine receptors), especially in SHR, indicating that sympathetic nerve transmission is facilitated by angiotensin II more in hypertensive than in normotensive animals. Thus, chronic ACE inhibition improves baroreflex sensitivity and lowers BP through both central and peripheral attenuation of sympathetic tone.