Changes In Arterial Blood Pressure Research Articles

The effects of sevoflurane anesthesia on hemodynamics and cerebral artery diameters in endovascular treatment of intracranial aneurysm: A pilot study.

Cerebral autoregulation is a steady-state of cerebral blood flow despite major changes in arterial blood pressure. Inhalation anesthetics are cerebral vasodilators. In <1 MAC values, the net effect is a moderate decrease in cerebral blood flow and maintenance of responsiveness to carbon dioxide. This study aims to investigate the effects of steady-state sevoflurane anesthesia on hemodynamic and cerebral artery diameter measurements in patients undergoing flow diverter device placement under general anesthesia. Forty-six patients aged 18-70 years who underwent flow diverter devices under general anesthesia were included in this study. Routine monitoring was performed on the patients. Mean arterial pressure (MAP) values were recorded. Internal carotid artery, middle cerebral artery and anterior cerebral artery diameter measurements were made from digital subtraction angiography (DSA) images of patients with anterior aneurysms. Baseline artery, right posterior cerebral artery and left posterior cerebral artery diameter measurements were made from DSA images of patients with posterior aneurysms. These measurements were recorded as preoperative measurements. The same measurements were made from the DSA images performed before the Flow diverter device placement procedure performed under steady-state sevoflurane anesthesia for the same patients. These measurements were recorded as peroperative measurements. The average age of the patients was 56.6±15.1. The MAP of the patients before induction was 76.28±5.13 mmHg, MAP after induction was 64.36±3.23 mmHg, and MAP during sevoflurane anesthesia was 68.26±4.30 mmHg, there was a statistically significant difference. There was a statistically significant difference between the preoperative and perioperative values of anterior cerebral artery diameters. There was a strong relationship between the MAP change percentage and the ICA diameter change percentage (p<0.001, p=-0.785) and a moderate relationship between the MCA diameter change percentage (p=0.033, p=-0.338). In patients undergoing flow diverter devices, <1 MAC sevoflurane has a hemodynamic effect and creates significant vasodilation in the cerebral artery diameters.

Comparative Study Among Ephedrine, Norepinephrine and Phenylephrine Infusions to Prevent Spinal Hypotension During Cesarean Section. A Randomized Controlled Double-Blind Study

ABSTRACT Background: Spinal anesthesia is the recommended technique in elective cesarean sections. Usage of vasopressors is more widely accepted as an effective method for decreasing postspinal hypotension than fluid loading. However, the ideal vasopressor to prevent spinal hypotension during cesarean section has been a subject of much debate. It should maintain maternal blood pressure and placental perfusion, with minimal adverse effect on fetus and mother. Aim: The primary aim was to compare the effect of prophylactic infusion of phenylephrine versus norepinephrine versus ephedrine in the prevention of postspinal hypotension in elective cesarean section. The secondary aim was to assess their effects on neonate. Methods: Seventy-five patients were enrolled in this study and randomly divided into three groups. Group P received phenylephrine infusion and group N received norepinephrine infusion, while group E received ephedrine infusion. The changes in mean arterial blood pressure and heart rate were recorded throughout the surgery. Maternal and neonatal perioperative complications were controlled and recorded. Results: MAP were higher in the ephedrine group than the phenylephrine and norepinephrine groups. Maternal tachycardia was significantly more common in ephedrine, and bradycardia was more common in phenylephrine group without significant difference. Nausea and vomiting were more common in ephedrine group. Neonatal acidosis was lesser in phenylephrine and norepinephrine groups than in the ephedrine group. Conclusion: Prophylactic infusion of phenylephrine and norepinephrine can be successfully used to prevent postspinal hypotension in parturient undergoing cesarean section with less drawbacks and fetal well-being than ephedrine.

The effect of oral glucose tolerance testing on changes in arterial stiffness and blood pressure in elderly women with hypertension and relationships between the stage of diabetes and physical fitness levels.

[Purpose] The purpose of this study was to assess changes in blood glucose level, blood pressure, and arterial stiffness after a 75 g oral glucose tolerance test (OGTT) in elderly women aged over 65 years with hypertension and either normal glycemic control, impaired fasting glucose tolerance, or diabetes mellitus. We also wished to investigate the relationship between stages of diabetes and physical fitness.[Methods] A total of 24 elderly women with hypertension were assigned to a control group (CON; n=7), impaired fasting glucose group (IFG; n=9), and diabetes mellitus group (DM; n=8). In each group, blood glucose level, brachial ankle pulse wave velocity (PWV), and blood pressure were measured at baseline as well as 60 and 120 minutes after a 75 g OGTT. Physical fitness factors such as hand grip strength, balance test, 4 m gait speed test, chair stand test, short physical performance battery, and 6-minute walking test were subsequently assessed.[Results] In all three groups, blood glucose levels were significantly increased at 60 and 120 minutes after a 75 g OGTT. In the DM group, blood glucose levels were significantly higher before and after a 75 g OGTT than in the CON group. In the CON group, PWV was significantly increased at 60 minutes after a 75 g OGTT; however, there were no changes in other groups after glucose ingestion. In the CON group, systolic and diastolic blood pressures were significantly decreased at 60 and 120 minutes after a 75 g OGTT compared to baseline. However, there was no change in blood pressure after ingestion in the DM group. The IFG group had greater grip strength than the CON group; however, there were no differences in other variables between the groups.[Conclusion] After a 75 g OGTT, elderly women with hypertension and diabetes maintain higher blood glucose levels compared to those with hypertension alone. Unlike elderly women with hypertension alone, those with hypertension and diabetes did not show changes in arterial stiffness and blood pressure after a 75 g OGTT. Therefore, elderly women with hypertension and diabetes may not be able to control their blood vessels following a 75 g OGTT due to impaired vascular endothelial function. Moreover, there was no association between diabetes stage and physical fitness in elderly women with hypertension.

Changes in Arterial Blood Pressure and Oxygen Tension as a Result of Hoisting in Isoflurane Anesthetized Healthy Adult Horses.

Background: In anesthetized adult horses, changes in recumbency can influence the cardiovascular system but how arterial blood pressures and oxygen tension change in isoflurane anesthetized animals as a direct result of hoisting has not been investigated.Objective: To evaluate effects of hoisting on hemodynamic function and pulmonary gas exchange in isoflurane-anesthetized horses.Study Design: Prospective, experimental study.Methods: Six adult horses were anesthetized three times using isoflurane in pure oxygen (inspired fraction 0.9–1.0), and allowed breathing spontaneously in lateral recumbency. After 45 min horses were hoisted using a single hoist-hobble system for 5 min and returned into left lateral recumbency. Heart rate (HR), respiratory rate (RR), and systolic (SAP), diastolic (DAP), and mean arterial blood pressures (MAP) were measured every minute starting from 5 min before to 5 min after hoisting. Arterial blood gas samples were collected before, during, and after hoisting.Results: Significant changes in hemodynamic parameters and PaO2 but not PaCO2 were found between baseline recordings and measurements obtained during and early after hoisting. The MAP decreased within the 1st min of hoisting from a mean of 74 ± 17 mmHg at baseline to 57 ± 20 mmHg (p < 0.05). Thereafter, it rapidly recovered to baseline before continuing to rise to higher than baseline values and then remaining elevated for 5 min after horses were returned into lateral recumbency. Simultaneously, the HR increased by 6–9 beats per min during the initial 3 min of hoisting before returning close to baseline values (p < 0.05). The PaO2 decreased significantly from a mean of 324.9 ±137.0 mmHg at baseline to a mean of 141.3 ± 104.2 mmHg during hoisting (p < 0.001) without recovering any more to baseline values.Clinical significance: Hoisting an adult horse during or at the end of isoflurane anesthesia carries the risk of a precipitous, though short-lived (1–2 min), drop in arterial blood pressures and a persistent decrease in arterial oxygenation. While in systemically healthy animals the observed functional impairments were not life-threatening, they may be more severe in systemically compromised horses.Therefore, arterial blood pressures and oxygenation must be carefully monitored when hoisting sick equine patients during or at the end of inhalant anesthesia.

Cross-sectional study on hearing loss and auditory reaction time before and after spinal anesthesia with marcaine 0.5% in patients undergoing elective surgery

BackgroundHearing loss is a rarely reported complication of spinal anesthesia. The purpose of this study is to assess the effects of 0.5% Maracine (bupivacaine) on hearing threshold and auditory reaction time before and after spinal anesthesia among patients undergoing elective surgery. Materials and methodsThis is a descriptive cross-sectional study performed on 60 patients undergoing elective surgery with ASA Class II and II anesthesia (0.5% bupivacaine) at Khorramabad Nursing Home. After obtaining consent from the patients, audiometry and tympanometry tests were performed using AZ80 and Madsen otoflex tympanometer and related findings including the presence or absence of hearing loss at various frequencies, before and after the surgery, were noted in a form for each patients along with their demographic data. SPSS 21 was used for statistical analysis and the data were analyzed using descriptive statistics and chi-square inferential tests. ResultsAt low frequencies of 250 and 500 Hz, no significant difference in pre- and postoperative hearing threshold in the right ear (P > 0.05) was seen, but at frequencies above 500 Hz, the hearing threshold was significantly decreased after surgery, (P < 0.05). In the left ear at 250, 1000, 3000, and 8000 Hz, there was no significant difference (P > 0.05) between pre- and postoperative hearing threshold. The results of this study showed that the preoperative hearing threshold for men and women did not differ and the auditory threshold and auditory response time after surgery did not differ between the two sexes (P > 0.05). Similarly, the difference was not correlated with the age and the levels of anesthesia (P > 0.05). The results also showed that changes in mean arterial blood pressure (MAP) and heart rate above 30% of baseline were also not correlated with hearing loss (P > 0.05). ConclusionsThe results showed that at certain frequencies, hearing loss was observed in both ears after spinal anesthesia with 5% Marcaine, but this hearing loss was not related to age, sex, and spinal anesthesia level. The results also showed that changes in mean arterial blood pressure (MAP) and heart rate above 30% of baseline did not correlate with hearing loss.

Association arterial stiffness reduction with improved left ventricular longitudinal and torsional deformation after 3 years of antihypertensive treatment

Abstract Background We investigated the effects of antihypertensive treatment on vascular function, longitudinal and torsional deformation in hypertensives. Methods In 200 untreated patients with arterial hypertension (age 52.5±11.6 years, 56% females), we measured at baseline and after a 3-year of antihypertensive treatment (160 received ACEi± diuretics and 40 CCBs± diuretics): a) 24h ambulatory blood pressure b) Carotid-femoral pulse wave velocity (PWV) b) Coronary flow reserve (CFR), LV mass index (LVMI), the global longitudinal strain (GLS) and diastolic (LongSRSE) strain rate, peak twisting (Tw-deg) and untwisting at mitral valve opening (UtwMVO), at peak E (UtwE) and at the end of the E wave (UtwendE) of the mitral inflow as well as twisting (TwVel-deg/sec) velocity using speckle tracking imaging. We calculated the % change of LV untwisting as difference between peakTw and UtwMVO, UtwpeakE and UtwendE. Results Compared to baseline, there was an improvement of GLS (−19.9±3.4 vs. −18.7±3.1%), LongSRS (−1.08±0.22 vs. −0.98±0.26 1/s), LongSRE (1.09±0.36 vs. 0.99±0.31 1/s), peak Tw (16.2±5.1 vs. 18.7±5.9 deg), Tw velocity, and the %LV untwisting (31.04±19.28 vs 26.02±15.69% at MVO, 60.04±19.78 vs 53.96±19.76% at peakE and 79.98±14.24 vs 75.90±17.01% at endE) post-treatment. In parallel, CFR (2.72±0.61 vs. 2.55±0.64), PWV (10.34±1.93 vs. 11.2±2.08 m/s) and LVMI were improved (p&amp;lt;0.01 for all comparisons). By ANOVA, the interaction term between changes of all the above parameters and antihypertensive treatment (ACE inhibitors vs calcium channel blockers) was not significant (p&amp;gt;0.05). By multivariate analysis, the reduction of 24h meanBP and PWV independently determined the respective improvement of GLS (b=0.478 and b=0.248 respectively), LongS (b=0.428 and b=0.201 respectively) as well as Twisting (b=0.449 and b=0.294 respectively) after adjusting for changes in LV mass, CFR and atherosclerotic risk factors (p&amp;lt;0.05). Conclusions Long-term optimal blood pressure control with ACE inhibitors and CCBs improves LV longitudinal and torsional mechanics in hypertensives in parallel with arterial stiffness and blood pressure. This improvement in LV deformation and twisting was independently related to changes in arterial blood pressure and arterial stiffness. Funding Acknowledgement Type of funding source: None

The critical closing pressure contribution to dynamic cerebral autoregulation in humans: influence of arterial partial pressure of CO2.

Dynamic cerebral autoregulation (CA) is often expressed by the mean arterial blood pressure (MAP)-cerebral blood flow (CBF) relationship, with little attention given to the dynamic relationship between MAP and cerebrovascular resistance (CVR). In CBF velocity (CBFV) recordings with transcranial Doppler, evidence demonstrates that CVR should be replaced by a combination of a resistance-area product (RAP) with a critical closing pressure (CrCP) parameter, the blood pressure value where CBFV reaches zero due to vessels collapsing. Transfer function analysis of the MAP-CBFV relationship can be extended to the MAP-RAP and MAP-CrCP relationships, to assess their contribution to the dynamic CA response. During normocapnia, both RAP and CrCP make a significant contribution to explaining the MAP-CBFV relationship. Hypercapnia, a surrogate state of depressed CA, leads to marked changes in dynamic CA, that are entirely explained by the CrCP response, without further contribution from RAP in comparison with normocapnia. Dynamic cerebral autoregulation (CA) is manifested by changes in the diameter of intra-cerebral vessels, which control cerebrovascular resistance (CVR). We investigated the contribution of critical closing pressure (CrCP), an important determinant of CVR, to explain the cerebral blood flow (CBF) response to a sudden change in mean arterial blood pressure (MAP). In 76 healthy subjects (age range 21-70years, 36 women), recordings of MAP (Finometer), CBF velocity (CBFV; transcranial Doppler ultrasound), end-tidal CO2 (capnography) and heart rate (ECG) were performed for 5min at rest (normocapnia) and during hypercapnia induced by breathing 5% CO2 in air. CrCP and the resistance-area product (RAP) were obtained for each cardiac cycle and their dynamic response to a step change in MAP was calculated by means of transfer function analysis. The recovery of the CBFV response, following a step change in MAP, was mainly due to the contribution of RAP during both breathing conditions. However, CrCP made a highly significant contribution during normocapnia (P<0.0001) and was the sole determinant of changes in the CBFV response, resulting from hypercapnia, which led to a reduction in the autoregulation index from 5.70±1.58 (normocapnia) to 4.14±2.05 (hypercapnia; P<0.0001). In conclusion, CrCP makes a very significant contribution to the dynamic CBFV response to changes in MAP and plays a major role in explaining the deterioration of dynamic CA induced by hypercapnia. Further studies are needed to assess the relevance of CrCP contribution in physiological and clinical studies.

Magnitude and Clinical Predictors of Blood Pressure Changes in Patients Undergoing Hyperbaric Oxygen Therapy: A Retrospective Study.

Hyperbaric oxygen therapy (HBOT) is widely used to treat several pathologies. The hemodynamic changes during HBOT, particularly the magnitude of arterial blood pressure (ABP) increase, are not completely understood. No clinical predictors for HBOT-induced ABP increase have been described. The purpose of this study was to quantify ABP changes in patients undergoing HBOT and to examine their predictors. This retrospective longitudinal cohort study examined 3291 elective HBOT sessions. Non-invasive ABP was recorded before and after each session. The primary outcome was to quantify the HBOT-induced ABP rise. The secondary outcome was to determine the ABP-rise predictors among demographic and clinical variables. Overall, ABP increased significantly after HBOT; this finding was more evident in the hypertensive subgroup compared to the normotensive one (+6 vs. +16.2 mmHg). Clinical predictors of significant post-HBOT ABP change were history of hypertension and pre-session baseline ABP classification. This study demonstrates an absolute HBOT-induced ABP rise. This change is clinically relevant in patients with history of hypertension. A higher baseline ABP seems a risk factor for clinically relevant ABP change. Pre-session ABP should be used clinically as an indicator for strict ABP monitoring during HBOT; future studies are recommended to explore the ABP optimization before starting an HBO treatment.

Features of hemodynamics of pulmonary circulation during the diving reflex

The adaptive cardiovascular reactions of the human diving reflex were studied. The diving reflex was activated by submerging a face in cold water under laboratory conditions. Forty volunteers (aged 18–24) were examined. ECG, arterial blood pressure (ABP) and central blood flow were recorded by the impedance rheography method in resting state, during diving simulation (DS) and after apnea. During DS there is a statistically significant decrease in the dicrotic index (DCI), which reflects a decrease in the resistive vessel tone and as well as diastolic index (DSI), characterizing lung perfusion. A comparison of the latent periods (LP) of an increase in ABP and a drop in DCI showed that a decrease in pulmonary vascular tone develops faster than ABP begins to increase. The LP for lowering DCI is from 0.6 to 10 s; for an increase in ABP — from 6 to 30 s. A short LP for DCI and the absence of a correlation between a decrease in ABP and DCI suggests that a decrease in pulmonary vascular tone during DS occurs reflexively and independently of a change in ABP.

Local anesthesia in piglets undergoing castration-A comparative study to investigate the analgesic effects of four local anesthetics on the basis of acute physiological responses and limb movements.

Surgical castration of male piglets without analgesia is a painful procedure. This prospective, randomized and double-blinded study aimed to evaluate the analgesic effects of four different local anesthetics for piglet castration during the first week of life. In total, 54 piglets aged 3 to 7 days were distributed into 6 treatment groups: handling (H); castration without pain relief (sodium chloride, NaCl); and castration with a local anesthetic: 4% procaine (P), 2% lidocaine (L), 0.5% bupivacaine (B) or 20 mg/ml mepivacaine (M). By excluding stress and fear as disruptive factors via a minimum anesthesia model, all piglets received individual minimum alveolar concentration (MAC) isoflurane anesthesia. Twenty minutes before castration, all treatment groups except group H received one injection per testis. Then, 0.5 ml of a local anesthetic or NaCl was injected intratesticularly (i.t.), and 0.5 ml was administered subscrotally. Acute physiological responses to noxious stimuli at injection and castration were evaluated by measuring blood pressure (BP), heart rate (HR), cortisol, epinephrine, norepinephrine and chromogranin A (CgA); limb movements were quantified. The results confirm that castration without analgesia is highly painful. Surgical castration without pain relief revealed significant changes in mean arterial blood pressure (MAP) and HR. Local anesthetic administration significantly reduced changes in BP and HR associated with castration. Piglets receiving a preoperative local anesthetic exhibited the fewest limb movements during castration, while the NaCl group exhibited the most. Injection itself was not associated with significant changes in MAP or HR. However, many piglets exhibited limb movements during injection, indicating that the injection itself causes nociceptive pain. No significant differences were found between groups regarding parameters of plasma cortisol, catecholamines and CgA. In conclusion, all four local anesthetics administered are highly effective at reducing signs of nociception during castration under light isoflurane anesthesia. However, injection of a local anesthetic seems to be painful.

The effect of body position on maternal cardiovascular function during sleep and wakefulness in late pregnancy

Introduction An association between the increased risk of late stillbirth and the maternal supine sleeping position has been recently established. The risk of stillbirth following supine sleep has been suspected to occur as a result of aortocaval compression by the gravid uterus. A number of studies conducted during wakefulness have reported compromised cardiovascular function during supine rest, as demonstrated by reductions in cardiac output, blood pressure and utero-placental blood flow. It remains unclear whether similar effects are also present during sleep, due to the presence of key sleep-specific changes in cardiovascular function. Objective To investigate the changes in maternal cardiovascular function between the supine and left-lateral positions during wakefulness and non-rapid eye movement (NREM) sleep in late pregnancy. Methods Twenty-nine women with a singleton pregnancy between 24.7 and 36.7 weeks’ gestation participated in a single overnight sleep study. Physiological measures (blood pressure, heart rate, heart rate variability – HRV, and pulse arrival time – PAT) were measured and recorded throughout the night using standard polysomnography equipment and the Portapres Model-2 device. As the present study evaluated cardiovascular changes during natural rest and sleep in pregnancy, participants were not given explicit instructions on which position to adopt. Body position was continuously recorded using a position monitor and verified with video recording. Results No changes in systolic, diastolic or mean arterial blood pressure were observed between the left-lateral and supine positions during wakefulness or sleep. However, heart rate was significantly higher in the supine position compared to the left during wakefulness (p= .03), with a similar trend present during sleep (p= .11). A significantly shorter PAT was measured in the supine position (compared to the left) during wakefulness (p= .01) and sleep (p= .01). No change in HRV measures was observed between the left and supine positions in either state. Conclusion Blood pressure did not appear to differ significantly between the left-lateral and supine positions during wakefulness and sleep. The lack of blood pressure differences may reflect elevated sympathetic activity during rest and sleep in the supine position (compared to the left), suggesting that some degree of compensation for aortocaval compression may still be possible during sleep.

Peripheral Revascularization Reverses The Decline In Active Muscle Oxygen Saturation In Peripheral Artery Disease

Peripheral artery disease (PAD) is a progressive atherosclerotic disease that limits blood flow to the skeletal muscles in the lower extremity. Reductions in blood flow may be more pronounced during ambulation or exercise and produce leg cramping or pain known as intermittent claudication. Recent studies have shown an exaggerated blood pressure response with lower muscle oxygen saturation (SmO2) during foot exercise in patients with PAD. However, it is unclear whether surgical and/or endovascular interventions normalize this response. PURPOSE: To examine whether revascularization procedures improve calf muscle SmO2 and reduce blood pressure responses during dynamic foot exercise in patients with PAD. We hypothesized that revascularization would improve SmO2 responses (indicating greater tissue perfusion) and that the blood pressure response would be attenuated during exercise. METHODS: Patients with symptomatic PAD (n = 6) performed incremental supine plantar flexion exercise, starting at 0.5 kg and increased by 0.5 kg every minute for up to 6 minutes, pre- and one-month post peripheral revascularization procedure. SmO2 was measured continuously from the gastrocnemius muscle, while heart rate and blood pressure were measured beat-by-beat. RESULTS: Reductions in SmO2 from baseline to end-exercise were attenuated post-revascularization (-6.5 ± 6.2% vs. -39.8 ± 22.5%, P < .05). The change in mean arterial blood pressure was reduced post-revascularization (4 ± 4 mmHg vs. 16 ± 12 mmHg P < .05). PAD patients exercised longer post-revascularization (5.8 ± 0.4 min vs. 4.0 ± 1.5 min P < .05). CONCLUSIONS: These data suggest that revascularization lessens the degree and rapidity of decline in SmO2 during exercise, and lowers the exaggerated blood pressure response in patients with PAD. Supported by NIH Grant P01 HL134609

Immediate changes in blood pressure during intravitreal anti-VEGF agents' applications in exudative age-related macular degeneration patients

To determine the short-term changes in systemic arterial blood pressure (SABP) during intravitreal anti-vascular endothelial growth factor (anti-VEGF) injection in patients with exudative age-related macular degeneration (ARMD). This study retrospectively reviewed the data of 550 patients with exudative ARMD, who received intravitreal anti-VEGF (bevacizumab or ranibizumab; selected randomly) injections. Patients with hypertension on medication with antihypertensive drugs were assigned to the hypertension group (HTG; n = 278); those with normal blood pressure and not on antihypertensive drugs were assigned to the normotensive group (NTG; n = 272). The SABP levels were measured 30min before anti-VEGF injection (baseline = B), during anti-VEGF injection (DI), as well as 30th (I30) and 60th (I60)min after anti-VEGF injection. Both groups had significantly higher systolic blood pressure (SBP) at DI than that of the baseline values (p < 0.001), whereas the diastolic blood pressures (DBP) increased significantly at DI, I30, and I60 compared with baseline (p < 0.001). In NTG, SBP was significantly higher in patients at I30 (p = 0.019), whereas that in HTG was significantly higher at all measurements (p < 0.05) only in patients who received intravitreal bevacizumab injection. Our study results show that intravitreal anti-VEGF injection is associated with a short-term increase in SABP. To prevent potential systemic complications during anti-VEGF administration, the systemic status of patients with ARMD should be evaluated before the injection and those with a risk of high SABP during injection should be closely monitored.

The Impact of High Dietary Sodium on Cerebral Blood Flow Regulation

High salt consumption is linked to increased stroke risk. In rodents, high dietary sodium has been shown to impair cerebral blood flow regulation. In humans, cerebrovascular reactivity to carbon dioxide (CO2) is a validated method for assessing the cerebrovasculature where a reduction in cerebrovascular reactivity is associated with cerebrovascular disease. Additionally, the ability for the brain to maintain cerebral blood flow despite changes in arterial blood pressure is termed cerebral autoregulation (CA). Dysfunctional CA is also predictive of strokes and all‐cause mortality. However, the effects of a high dietary sodium consumption on cerebrovascular reactivity and dynamic CA in healthy, young adults is unknown.PurposeWe tested the hypothesis that ten days of high dietary sodium feeding would impair cerebral blood flow regulation in healthy young adults.MethodsEight adults (6M/2F; age: 29 ± 11yrs; BMI: 26±3 kg/m2, Mean‐±SD) participated in a controlled feeding study that consisted of 10 days of either low‐ (LS: 1 g sodium/day), medium‐ (MS: 2.3 g sodium/day), or high‐sodium (HS: 7 g sodium/day) diets, in randomized order separated by at least a month. Urinary sodium excretion was determined to ensure compliance on diets. Transcranial Doppler of the right middle cerebral artery (MCA) velocity was assessed while participants lay supine. On the tenth day of the diet, cerebrovascular reactivity to high CO2 (via 8% CO2; hypercapnia) and low CO2 (via hyperventilation; hypocapnia) were assessed. Dynamic CA between spontaneous changes in mean arterial pressure to MCA velocity using a transfer function analysis was also measured. Data were analyzed using one‐way repeated measures ANOVA. Tukey post hoc comparisons were used when appropriate.ResultsUrinary sodium excretion (LS= 64±56, MS= 82±19, HS=250±213 mmol/24h, P=0.04) increased in a step‐wise manner. Brachial blood pressures were not different (systolic blood pressure= P=0.45; diastolic blood pressure: P=0.17). Cerebrovascular reactivity to hypercapnia (LS= 2.4±0.6, MS= 1.7±0.5, HS=2.5±0.7 %/mmHg, P=0.09) and to hypocapnia (LS= 1.8±0.6, MS= 1.9±0.6, HS=2.0±0.7 %/mmHg, P=0.72) were not different. Dynamic CA was also not different in the very low frequency (phase: LS= 71±23, MS= 72±38, HS=80±39°, P=0.69) and low frequency band (phase: LS= 42±14, MS= 45±11, HS=47±14°, P=0.62).ConclusionDespite the diets, these preliminary data suggest that high dietary sodium may not impair cerebral blood flow regulation in healthy young adults.Support or Funding InformationAcknowledgementsNIH Grant 1RO1HL128388

Frequency and individual severity of arterial blood pressure changes in children and adolescents with attention-deficit/hyperactivity disorder treated with methylphenidate hydrochloride: a prospective non-interventional study

BackgroundAttention-deficit/hyperactivity disorder (ADHD) is a common behavioural disorder in childhood. The psychostimulant methylphenidate hydrochloride (MPH) is one of the major pharmacological options for ADHD. MPH is known to result, on...

Angiotensin Receptor Neprilysin Inhibition in Patients with Left Ventricular Assist Devices

Angiotensin receptor neprilysin inhibitors (ARNI) are now an established therapy for HF pts. While LVADs are a life-prolonging treatment for advanced HF, optimal management of hypertension and HF in this population is not known. We sought to evaluate the safety and efficacy of ARNI therapy in LVAD pts. We retrospectively reviewed all LVAD pts implanted between 8/2010 and 5/2019 who were subsequently treated with ARNI for at least 3 months. The primary outcome was change in NT-proBNP between the time of ARNI initiation (t0) and at 3- and 6-mo follow up. Safety endpoints included changes in mean arterial blood pressure (MAP), serum creatinine and potassium pre- and post-ARNI therapy. Data on concomitant drug therapy including diuretic dosing equivalents were also gathered. The above mentioned variables were log-transformed prior to analysis with repeated measures ANOVA. Pairwise comparisons were performed with Bonferroni's post hoc test. 30 pts met our inclusion criteria (age 54.7 ± 15.5 y; 90% M; HM3 17[57%], HMII 12[40%], HVAD 1 [3%]). ARNI was initiated at a median of 250 [67 - 601] days after LVAD implant. Prior to ARNI initiation, 47% were on ACE inhibitor, 13% on ARB, 40% on neither and 60% were treated with diuretics, with an average oral furosemide equivalent dose of 34 mg/day. At t0, 73% were started on 24/26 mg, and at 6 mos, 27% were on 49/51 mg and 32% on 97/103 mg of ARNI (Table). There was no statistically significant change in median MAP, serum creatinine or potassium (Table). A significant decrease in NT-proBNP was noted from t0 to follow-up (t0 = 1082 pg/mL, 3 mos = 724 pg/mL, 6 mos = 651 pg/mL) (Figure). The use of ARNI therapy was well tolerated among LVAD pts. There was a significant decrease in NT-proBNP levels, an effect previously reported in HF pts without LVADs in the PARADIGM-HF and PIONEER-HF trials. Randomized studies to determine the role of ARNI on the clinical course of LVAD patients are warranted.

Comparison of the Effect of Combined Cardiovascular Dexmedetomidine and Propofol in Minimally Invasive axillary Odor Surgery with Tumescent Anesthesia

Objective: The effects of combined dexmedetomidine hydrochloride and propofol in minimally invasive axillary odor surgery with tumescent anesthesia. Methods: A total of 46 patients underwent minimally invasive axillary odor surgery by tumescent anesthesia received in the hospital from May 2017 to January 2019 were divided into observation group (23 cases) and control group (23 cases) according to the random number table method. The control group used propofol, and the observation group underwent minimally invasive axillary odor combined with dexmedetomidine hydrochloride by tumescent anesthesia. The changes of arterial blood pressure (MAP), heart rate (HR) and postoperative complications before and after anesthesia were compared and analyzed between the two groups. Results: After anesthesia, MAP and HR in both groups were lower than before anesthesia, and the observation group was lower than the control group, the difference was statistically significant (P&lt;0.05). Compared with the control group, the postoperative complications were less in the observation group, but the difference was not statistically significant (P&gt;0.05). Conclusion: Compared with the use of propofol, the effect of dexmedetomidine hydrochloride combined with minimally invasive axillary odor surgery by tumescent anesthesia is more obvious, and the postoperative recovery is faster with fewer complications.

Cerebrovascular reactivity to carbon dioxide is not influenced by variability in the ventilatory sensitivity to carbon dioxide.

What is the central question of this study? Do differing magnitudes of ventilation influence cerebrovascular CO2 reactivity and the cerebral blood flow response to increases in arterial carbon dioxide? What is the main finding and its importance? While a greater ventilation, through voluntary hyperventilation, is associated with a higher anterior cerebral blood flow during carbon dioxide breathing, this elevated cerebral blood flow is due to a higher blood pressure and not ventilation per se. A greater ventilation, through voluntary hyperventilation, does not influence global or posterior cerebral blood flow during carbon dioxide breathing. Cerebrovascular reactivity to carbon dioxide is not influenced by an individual's ventilatory sensitivity to carbon dioxide. Recent work demonstrated an influence of ventilation on cerebrovascular reactivity to CO2 ; however, the concomitant influence of changes in mean arterial blood pressure (MAP) on ventilation-induced differences in cerebral blood flow (CBF) has yet to be examined in this context. Healthy participants (n=15; 25±3years of age; 179±6cm height; 74±10kg weight; 3 female) underwent end-tidal forcing to increase their partial pressure of end-tidal CO2 by +3, +6 and +9mmHg above baseline in 5-min sequential steps while maintaining iso-oxia. This protocol was then repeated twice, with participants hyperventilating and hypoventilating by ∼30% compared to the first trial. Intra-cranial and extra-cranial CBF were measured using ultrasound. The MAP (finger photo-plethysmography) was higher during the hyperventilation and hypoventilation trials compared to normal ventilation (main effects, P<0.05 for both). While internal carotid artery blood flow was higher during the hyperventilation trial compared to normal ventilation (P=0.01), this was due to a higher MAP, as indicated by analysis of conductance values (P=0.68) or inclusion of MAP in covariate analysis (P=0.11). Global CBF (P=0.11) and vertebral artery blood flow (P=0.93) were unaffected by the magnitude of ventilation. Further, CO2 reactivity was not affected by the different breathing trials (P>0.05 for all). Retrospective analysis of a larger data set (n=53) confirmed these observations and demonstrated no relationships between the ventilatory and global CBF response to hypercapnia (r2 =0.04; P=0.14). Therefore, when differences in MAP are accounted for, cerebrovascular CO2 reactivity (assessed via end-tidal forcing) is independent of the magnitude of ventilation.

Rhythmic Breath Holding and Its Effect on Arterial Blood Pressure and Its Correlation With Blood Gases

A single episode of breath-holding (BH) is known to elevate the blood pressure, and regular breathing exercise lowers the blood pressure. This prompted us to investigate how a series of BH epochs would affect the cardiovascular system. To observe arterial blood pressure (ABP) and heart rate (HR) changes associated with a series of “BH epochs” following maximum inspiration and maximum expiration and find the underlying mechanisms for the change by autonomic activity. Thirty-five healthy young adults were instructed to hold their breath repetitively, for 5 minutes, in two patterns, one following maximum inspiration and other following maximum expiration. ABP and ECG (for Heart Rate Variability) were continuously recorded at rest and during both the maneuvers. Capillary blood gases (BG) were zanalyzed at baseline and at the breakpoint of the last epoch of BH. ABP rose significantly at the breakpoint during both the maneuvers. No change in HR was observed. There was significant fall in PO2 from 94.7 (4.1) mmHg at baseline to 79.1 (9.0) mmHg during inspiratory and 76.90 (12.1) mmHg during expiratory BH. Similarly, SPO2 decreased from 96.3 (1.9) % at baseline to 95.4 (1.5) % and 94.5 (2.7) % during inspiratory and expiratory BH, respectively. Rise in PCO2 from 39.5(3.1) mmHg at baseline to 42.9 (2.7) mmHg and 42.1 (2.8) mmHg during inspiratory and expiratory BH respectively was observed. There was no significant correlation between blood gases and arterial blood pressure. Among HRV parameters, a significant decrease in SDNN, RMSSD, HFnu, total power and SD1/SD2 and the significant increase in LFnu, LF/HF and SD2 were observed during both BH patterns. Rhythmic BH patterns affect the cardiovascular system in similar way as a single episode of BH. Sympathetic overactivity could be the postulated mechanism for the same. © 2019 Tehran University of Medical Sciences. All rights reserved. Acta Med Iran 2019;57(8):492-498.

Relationship Between Arterial Blood Pressure During Trigeminal Nerve Combing and Surgical Outcome in Patients with Trigeminal Neuralgia

Changes in blood pressure during trigeminal combing have been discussed in recent years. In this study, a retrospective analysis of patients with trigeminal neuralgia (TN) requiring microvascular decompression (MVD) with nerve combing was carried out to investigate fluctuation in arterial blood pressure during trigeminal nerve combing and its surgical effect and corresponding pathogenesis. A total of 70 cases of MVD with nerve combing performed during the treatment of primary TN patients were selected between January 2017 and January 2018 at Peking University People's Hospital. The degree of pain and prognosis of the patients were evaluated according to the visual analog scale. Postoperative facial numbness of the 2 groups were assessed by the Barrow Neurological Institute facial numbness score. Arterial blood pressure changes before and while combing the trigeminal nerve during MVD were dynamically monitored, and the patients were divided into responders and nonresponders. Total adrenaline (AD), norepinephrine (NE), and dopamine values were measured before and during trigeminal nerve combing. Increased arterial blood pressure during the combing of the trigeminal nerve in MVD had a significant correlation with the prognosis of patients, with patients with higher arterial blood pressure having a better prognosis (P < 0.05). In the increased arterial blood pressure patients, precombing total AD and NE means were dramatically improved (P < 0.05). This study shows that changes in arterial blood pressure during trigeminal nerve combing in MVD were correlated with the prognosis of patients. Further research is necessary to clarify the mechanism of increased arterial blood pressure.