Significant Differences In Heart Rate Research Articles

The peculiarities of changes in myocardial electrical activity and heart rate variability in patients with coronary artery disease depending on the stage of concomitant iron deficiency

The aim of the study: to assess changes in myocardial electrical activity and heart rate variability (HRV) in patients with coronary artery disease (CAD) depending on the stage of iron deficiency (ID) and identify their relationship with ferrokinetic parameters. Materials and methods. In total, 90 patients with CAD, stable angina II–III FC were examined (men – 35, women – 55, age – 69 (61; 72) years). The patients were divided into 4 groups: the 1st group (n = 16) consisted of patients with concomitant ID anemia (IDA) of mild and moderate severity, the 2nd (n = 15) – with latent ID, the 3rd (n = 14) – with functional ID, the 4th (n = 45) – patients with CAD without iron metabolism disorders. The HRV features during 24 hours, daytime and nighttime as well as their relationships with ferrokinetic and hematological parameters were analyzed. The data analysis was performed using Statistica 13.0. Results. CAD patients with concomitant IDA demonstrated a tendency to have a higher average daytime heart rate value (U = 14.0; p ≈ 0.08), a longer duration of tachycardia (U = 20.0; p ≈ 0.06), and a significantly greater number (2.4 times) of ventricular extrasystoles (VE) (U = 7.0; p < 0.05) compared to patients without iron metabolism disorders. There were no statistically significant differences in heart rate, episodes of tachycardia, and the number of arrhythmic events in CAD patients with different stages of ID. During the temporal analysis of HRV indicators, patients with different stages of concomitant ID demonstrated a decrease in overall HRV due to SDNN-index, rMSSD (%) and HRVT triangular index both in active and passive periods as compared to patients without iron metabolism disorders. Spectral analysis of HRV has revealed reduced parasympathetic activity of the autonomic nervous system due to HF indicator in patients of the 1st–3rd groups. The presence of concomitant IDA was characterized by maximum changes in HRV indicators and the predominance of central mechanisms of HRV regulation over autonomic ones, which was confirmed by a significant increase in the centralization index (IC) and stress index (SI). For CAD patients with concomitant IDA and latent ID, a number of relationships between ferrokinetic and HRV parameters was found. There were no statistically significant correlations between indicators of iron metabolism and HRV in patients with CAD and functional ID. Conclusions. The decrease in iron stores in the body due to its tissue and transport reserves is accompanied by changes in the myocardial electrical activity, a progressive reduction in heart rate variability, autonomic dysfunction towards a suppression of the parasympathetic domain activity, confirming the relevant correlations with the ferrokinetic parameters.

Comparison between two different doses of Norepinephrine infusion for preventing post spinal Anesthesia Hypotension during Cesarean section

Introduction: Post spinal maternal hypotension is common complication during cesarean section. Norepinephrine is a vasopressor recently used in obstetrics anesthesia. However, there are less data available regarding its optimal dose.
 Objective: The main objective of this study is to compare two doses of infusion of norepinephrine for post spinal hypotension during cesarean delivery.
 Methodology: A prospective, randomized, double blinded study on full term pregnant patient scheduled for elective cesarean delivery. The infusion of Norepinephrine started after spinal anesthesia after patient randomly divided into two groups. Group A received norepinephrine infusion rate of 0.025ug/kg/min and Group B received at rate of 0.050ug/kg/min. The norepinephrine was continued till 5 minutes after the delivery of fetus and subsequently stopped. These two groups were compared with systolic blood pressure, mean arterial pressure, heart rate, intraoperative hypotensive episodes, Nausea and Vomiting, tachycardia and neonatal outcomes.
 Results: Systolic blood pressure and mean arterial pressure was higher in group B when compared with group A at all time intervals intraoperatively. The minimum systolic blood pressure and mean arterial blood pressure in group A were 91.61±8.76 and 59.8±5.29 and group B were 90.67±1.21 and 65±3.46 respectively. No significant difference in heart rate between the two groups. In 0.025ug/kg/min group had 23 (46%) hypotensive episode whereas in 0.050ug/kg/min group had 6 (12%) hypotensive episodes (p<0.001). In group A 9 patient had nausea and vomiting. Bradycardia was seen in 2 % of patient in group A. Tachycardia was seen in 4% of patients in group B. Apgar score was comparable and significant (P<0.05) in 10 minutes.
 Conclusion: In the present study, the infusion of 0.050ug/kg/min norepinephrine reduced the hypotensive episodes when compared with the infusion of 0.025ug/kg/min norepinephrine following spinal Anesthesia during cesarean delivery.

A Convenient and Effective Preoxygenation Technique for Prolonging Deep Inspiration Breath-Hold Duration With a Venturi Mask With a 50% Oxygen Concentration

Purpose: Voluntary deep inspiration breath-hold (DIBH) is commonly used in radiation therapy (RT), but the short duration of a single breath-hold, estimated to be around 20-40 seconds (s), is a limitation. This prospective study aims to assess the feasibility and safety of using a simple preoxygenation technique with a Venturi mask to prolong voluntary DIBH. Methods and materials: The study included 33 healthy volunteers and 21 RT patients. Preoxygenation was performed using a Venturi mask with a 50% oxygen concentration. Paired t-tests compared the duration of a single DIBH in room air and after 5, 15, and 30 minutes of preoxygenation in healthy volunteers. Sustainability of breath-hold and tolerability of heart rate and blood pressure were assessed for multiple DIBH durations in both volunteers and patients. Results: In healthy volunteers, a 15-minute preoxygenation significantly prolonged the duration of a single DIBH by 24.95s compared to 5-minute preoxygenation (89 ± 27.76s vs. 113.95 ± 30.63s, p < 0.001); although there was a statistically significant increase in DIBH duration following 30-minute preoxygenation, it only extended by 4.95s compared to 15-minute preoxygenation (113.95 ± 30.63s vs. 118.9 ± 29.77s, p < 0.01). After 15-minute preoxygenation, a single DIBH lasted over 100s in healthy volunteers and over 80s in RT patients with no significant differences among six consecutive cycles of DIBH. Furthermore, there were no significant differences in heart rate, or blood pressure after DIBHs, including DIBH in room air and six consecutive DIBH after 15-minute preoxygenation (all p > 0.05). Conclusions: Preoxygenation with a 50% oxygen concentration for 15 minutes effectively prolongs the duration of six cycles of DIBH both in healthy volunteers and RT patients. The utilization of a Venturi mask to deliver 50% oxygen concentration provides a solution characterized by its convenience, good tolerability, and effectiveness.

FRI478 Pharmacometrics-based Computer Model Utilizing Heart Rate To Monitor Thyroid Function In Children With Graves' Disease

Abstract Disclosure: B. Steffens: None. G. Koch: None. F. Claude: None. F. Bachmann: None. J. Schropp: None. M. Janner: None. D. l'Allemand: None. D. Konrad: None. M. Pfister: None. G. Szinnai: None. Graves’ disease (GD) with onset in childhood or adolescence is a pediatric rare disease (ORPHA:525731) with a ten times lower incidence than in adults. Leading clinical signs of hyperthyroidism are sinus tachycardia, weight loss, tremor, and goiter. First-line treatment are anti-thyroid drugs in order to normalize thyroid function. However, dose finding in pediatric GD is complex due to a broad spectrum of disease severity at diagnosis, and highly variable disease activity during follow-up, especially during puberty. As thyroid hormones have a strong positive chronotropic effect, heart rate (HR) turns out to be a useful clinical marker to monitor thyroid activity under treatment. Our overall aim was to provide a practical pharmacometrics-based (PMX-based) computer model characterizing both, individual FT4 dynamics and the relation between FT4 and tachycardia in children with various disease severity of GD during the first 120 days of treatment. Development of the PMX computer model was based on the non-linear mixed effects approach (i) linking FT4 kinetics with HR dynamics, (ii) accounting for inter-individual variability, and (iii) incorporating individual patient characteristics. Retrospectively collected clinical (resting heart rate during consultation) and laboratory data (FT4) from 41 children and adolescents with GD at four pediatric hospitals in Switzerland (75% female, median age 11.2 [IQR 8.5, 13.5] years) with 187 FT4 measurements and 132 HR measurements, and 124 paired measurements, were available and used for model development. Pediatric patients showed median FT4 of 59.6 [IQR 44.5, 73.0] pmol/l and median HR of 112 [IQR 100, 128] bpm at diagnosis. GD severity groups were defined based on FT4 measurement at diagnosis, resulting in equal numbers of mild (13), moderate (14) and severe (14) GD. We observed a significant difference in HR at diagnosis (p &amp;lt; 0.01) between the three GD severity groups based on FT4 at diagnosis. The final PMX computer model accounted for inter-individual variability and clinically relevant covariate effects such as age, gender, and GD severity, and was able to accurately predict FT4 and HR dynamics for each individual patient during the first 120 days of treatment. A PMX-based computer model that leverages individual HR dynamics can be applied to facilitate personalized pharmacotherapy in pediatric GD and mitigate the risk for under- or overdosing of anti-thyroid drugs in these patients. Prospective randomized validation trials are warranted to further validate and fine-tune such computer-supported personalized dosing in children with Graves’ disease. Presentation: Friday, June 16, 2023

Leukopenia and leukocytosis as strong predictors of COVID-19 severity: A cross-sectional study of the hematologic abnormalities and COVID-19 severity in hospitalized patients.

Predicting severe disease is important in provocative decision-making for the management of patients with the coronavirus disease 2019 (COVID-19); However, there are still some controversies about the COVID-19's severity predicting factors. This study aimed to investigate the relationships between clinical and laboratory findings regarding COVID-19's severity in patients admitted to a tertiary hospital in Mashhad, Iran. A cross-sectional study was conducted on patients with documented COVID-19 infection based on the reverse transcription-polymerase chain reaction test. Clinical symptoms, vital signs, and medical history of the patients were recorded from their medical records. Laboratory findings and computed tomography (CT) study findings were documented. Disease severity was defined based on CT scan findings. A total of 564 patients (58.8 ± 16.8 years old) were evaluated. The frequency of severe disease was 70.4%. There was a significant difference in heart rate (p = 0.0001), fever (p = 0.002), dyspnea (p = 0.0001), chest pain (p = 0.0001), diarrhea (p = 0.021), arthralgia (p = 0.0001), and chills (p = 0.044) as well as lymphopenia (p = 0.014), white blood cell count (p = 0.001), neutrophil count (p < 0.0001), lymphocyte count (p < 0.0001), and prothrombin time (p = 0.001) between disease severity groups. Predictors of severe COVID-19 were pulse rate (crude odds ratio [cOR] = 1.014, 95% confidence interval [CI] for cOR: 1.001, 1.027) and leukopenia (cOR = 3.910, 95% CI for cOR: 1.294, 11.809). Predictors for critical COVID-19 were pulse rate (cOR = 1.075, 95% CI for cOR: 1.046, 1.104), fever (cOR = 2.516, 95%CI for cOR: 1.020, 6.203), dyspnea (cOR = 4.190, 95% CI for cOR: 1.227, 14.306), and leukocytosis (cOR = 3.866, 95% CI for cOR: 1.815, 8.236). Leukopenia and leukocytosis have the strongest correlation with the COVID-19 severity. These findings could be a valuable guild for clinicians in COVID-19 patient management in the inpatient setting.

Low-dose nalmefene pretreatment reduces etomidate-induced myoclonus: A randomized, double-blind controlled trial.

This study compared the effectiveness of nalmefene and fentanyl in reducing the incidence and severity of etomidate-induced myoclonus. One hundred fifty patients were randomized to receive 0.25ug/kg of nalmefene, 1ug/kg of fentanyl, or the same volume of normal saline 3 minutes prior to etomidate-induced anesthesia. The primary observational indexes were the severity level and incidence of etomidate-induced myoclonus, and the secondary observational index included blood pressure, heart rate, and the incidence of adverse effects from anesthesia induction to resuscitation, such as cough, chest wall rigidity, dizziness, nausea, pain after awakening, and intraoperative awareness. The incidence of myoclonus was significantly lower in the nalmefene group (8.0%) than in the fentanyl group (32.0%) (P = .003) and in the normal saline group (72.0%) (P = .000). The severity level of myoclonus in the nalmefene group was significantly lower than the fentanyl group (P = .001) and normal saline group (P = .000). Meanwhile, the incidences of cough and chest wall rigidity during anesthesia induction were significantly lower in the nalmefene group compared with the fentanyl group (P = .003, P = .027). There were no statistically significant differences in heart rate and mean arterial pressure among the 3 gruops (P > .05). There was no difference in the incidence of adverse effects among the 3 groups during recovery from anesthesia (P > .05). Intravenous injection of 0.25ug/kg of nalmefene 3 minutes prior to etomidate is more effective in preventing etomidate-induced myoclonus during general anesthesia than 1ug/kg of fentanyl.

Poster (Clinical/Best Practice Implementation) ID 1981325

Background Many barriers prevent those with spinal cord injury or disease (SCI/D) from adhering to recommended exercise guidelines, thus increasing risks of secondary health conditions. Mainstream technology options, such as virtual reality (VR), have the potential to facilitate needed exercise participation. However, further research on VR exercise modalities is needed to determine feasibility, effectiveness and to ultimately guide practice recommendations. Objectives The goal of this pilot feasibility study was to determine whether VR exergaming is non-inferior to the current standard of care (SoC) upper extremity aerobic exercise for individuals with SCI/D. Methods/Overview 25 participants with SCI/D completed 10-minute exercise sessions with either VR or the SoC, and after a rest break, then completed 10 minutes of exercise with the other modality. Primary outcomes of heart rate (HR) and rate of perceived exertion (RPE) were collected at baseline, 5 minutes into exercise, and at 10 min (end of the exercise session) for each modality. Secondary exploratory measures included a Numeric Pain Rating Scale measured pre- and post- each exercise session, and a post-study likeability survey. Results There were no significant differences in HR or RPE between virtual reality exergaming and the standard of care, and 100% of participants preferred the VR over SoC for the exercise. Conclusions VR exergaming was non-inferior to the SoC for short duration upper extremity exercise in those with SCI/D. Implementing VR for patients with SCI/D should be studied further to observe the longer term effect on cardiovascular health and to determine feasibility and compliance for home use.

The application of iliac fascia space block combined with esketamine intravenous general anesthesia in PFNA surgery of the elderly: A prospective, single-center, controlled trial.

To observe the effect of iliac fascia space block combined with esketamine intravenous general anesthesia in proximal femoral nail antirotation (PFNA) of the elderly. Eighty elderly patients who underwent PFNA were randomly divided into experimental group and control group. In the experimental group, iliac fascial block combined with esketamine and propofol intravenous general anesthesia was used to keep spontaneous breathing. The control group used iliac fascia block combined with remifentanil and propofol intravenous general anesthesia to maintain spontaneous breathing. Record important indexes such as heart rate (HR), mean arterial pressure (MAP), pulse oxygen saturation (SpO2), visual analogue score (VAS) scores, etc. at different moment during the operation. Trial data showed that there were significant differences in HR, MAP, and SpO2 between the two groups at the beginning of operation, and there was no significant difference in VAS scores between the two groups at each moment after surgery, and there were significant differences in the number of vasopressor applications, length of hospital stay, and QoR-15 scores between the two groups, and there were significant differences in the incidence of total adverse reactions and the incidence of hypotension. The trial indicated that patients in the experimental group have more stable hemodynamics and lower stress response, which is conducive to rapid recovery after surgery.

Pain-related changes in crSO2 among premature infants undergoing PICC insertion

Objective To evaluate the effectiveness of cerebral regional oxygen saturation (crSO2) values, measured using near-infrared spectroscopy (NIRS), in assessing pain associated with the peripherally inserted central catheter (PICC) in premature infants. Methods NIRS was used to measure the crSO2 levels of 48 premature infants with gestational age (GA) of < 32 weeks or a birth weight of < 1500 g. Premature infant pain profile (PIPP) scores, vital signs, transcutaneous oxygen tension (TcpO2), transcutaneous carbon dioxide tension (TcpCO2), and crSO2 values were monitored. One-way repeated measure analysis of variance was used to compare heart rate (HR), respiratory rate (RR), blood pressure (BP), peripheral oxygen saturation (SpO2), TcpO2, TcpCO2, and crSO2 values before (Time 1), during (Time 2), and after (Time 3) PICC insertion. The correlation between the PIPP scores at Time 2 and the fluctuations (values detected at Time 2 minus those at Time 1) of SpO2, TcpO2, and crSO2 were also analyzed. Results The PIPP score at Time 2 was significantly higher than those at Times 1 and 3. HR, RR, and BP values increased (p < .05), and SpO2 and crSO2 levels decreased at Time 2 (p < .05) compared with those at Time 1. Stratified analysis based on GA revealed significant differences in HR, RR, and crSO2 values between Times 1 and 2 in infants with a GA of ≥ 32 weeks. In infants with a GA < 32 weeks, significant differences were observed in HR, RR, SpO2, BP, and crSO2 values between Times 1 and 2. The fluctuation of the crSO2 level was strongly correlated with the PIPP score at Time 2 (r = −0.829, p < .001). A weak correlation was observed between the PIPP score at Time 2 and TcpO2 level fluctuation (r = 0.375, p = .009). No correlation was observed between the PIPP score at Time 2 and SpO2 level fluctuation (r = 0.242, p = .097). Conclusion The fluctuation of crSO2 levels strongly correlates with PICC procedural pain. Hence, crSO2 levels measured using NIRS may be used as an indicator for pain assessment in premature infants.

Establishment of a Rat Model of Hypotension Induced by Reserpine

Objective To determine the optimal dosage and intervention duration of reserpine to establish a rat model of hypotension.Methods According to the body weight and systolic blood pressure (SBP),60 male Wistar rats were assigned to six groups (n=10),including a control group and five observation groups with different doses.The control group was administrated with 10 ml/kg 0.5% sodium carboxymethyl cellulose solution,and the observation groups with 0.016,0.032,0.064,0.128,and 0.160 mg/kg reserpine suspensions,respectively.All the groups were administrated by gavage twice a day,and the body weights of rats were monitored daily.SBP and heart rate (HR) were measured before modeling and 1-6 weeks after administration.After 6 weeks of administration,the blood samples of inner canthus were collected.The levels of lactate dehydrogenase (LDH),creatine kinase MB isoenzyme (CK-MB),alanine aminotransferase,aspartate aminotransferase (AST),serum creatinine,and blood urea nitrogen (BUN) were measured by an autoanalyzer.Three rats in each group were randomly selected for observation of the changes in SBP after drug withdrawal and the rest rats were sacrificed for measurement of the levels of norepinephrine and dopamine in the brain.Results Compared with the control group,different doses of reserpine lowered the SBP of rats (F=28.492,P<0.001).The decline in SBP increased in a concentration-dependent manner.SBP reached the lowest value after 1 week,rose slightly later,and was stable after 3 weeks of administration.There was no significant difference in SBP between 0.016 mg/kg reserpine group and the control group after the 5th week (P>0.05).The SBP levels of rats in 0.032,0.064,0.128,and 0.160 mg/kg reserpine groups showed no significant difference between each other (P=0.204) and were lower than that in the control group (all P<0.001).One week after drug withdrawal,the SBP of rats in the observation groups rose to the baseline level and remained stable.HR showed similar changes among groups,first increasing and then decreasing.There was no significant difference in HR among different groups at the same time point (F=0.922,P=0.475).Compared with the control group,reserpine of different doses reduced the norepinephrine content in the hippocampus (all P<0.001),and 0.128 mg/kg (P=0.045) and 0.160 mg/kg (P=0.042) reserpine lowered the dopamine level in the striatum,which showed no significant differences between different reserpine groups(P=0.343,P=0.301).The levels of LDH,CK-MB,and BUN in the serum increased with the increase in reserpine concentration,and the levels of LDH (P=0.001),CK-MB (P=0.020),AST (P=0.007),and BUN (P=0.001) in the 0.160 mg/kg reserpine group were significantly different from those in the control group.Conclusions The rat model of hypotension can be induced by gavage with reserpine.The gavage with reserpine at a dose of 0.032 mg/kg,twice a day for three consecutive weeks is the optimal scheme for the modeling.After the model establishment,continuous administration is essential to maintain the hypotension.

The challenge of measuring physiological parameters during motor imagery engagement in patients after a stroke.

It is suggested that eye movement recordings could be used as an objective evaluation method of motor imagery (MI) engagement. Our investigation aimed to evaluate MI engagement in patients after stroke (PaS) compared with physical execution (PE) of a clinically relevant unilateral upper limb movement task of the patients' affected body side. In total, 21 PaS fulfilled the MI ability evaluation [Kinaesthetic and Visual Imagery Questionnaire (KVIQ-10), body rotation task (BRT), and mental chronometry task (MC)]. During the experiment, PaS moved a cup to distinct fields while wearing smart eyeglasses (SE) with electrooculography electrodes integrated into the nose pads and electrodes for conventional electrooculography (EOG). To verify MI engagement, heart rate (HR) and oxygen saturation (SpO2) were recorded, simultaneously with electroencephalography (EEG). Eye movements were recorded during MI, PE, and rest in two measurement sessions to compare the SE performance between conditions and SE's psychometric properties. MI and PE correlation of SE signals varied between r = 0.12 and r = 0.76. Validity (cross-correlation with EOG signals) was calculated for MI (r = 0.53) and PE (r = 0.57). The SE showed moderate test-retest reliability (intraclass correlation coefficient) with r = 0.51 (95% CI 0.26-0.80) for MI and with r = 0.53 (95% CI 0.29 - 0.76) for PE. Event-related desynchronization and event-related synchronization changes of EEG showed a large variability. HR and SpO2 recordings showed similar values during MI and PE. The linear mixed model to examine HR and SpO2 between conditions (MI, PE, rest) revealed a significant difference in HR between rest and MI, and between rest and PE but not for SpO2. A Pearson correlation between MI ability assessments (KVIQ, BRT, MC) and physiological parameters showed no association between MI ability and HR and SpO2. The objective assessment of MI engagement in PaS remains challenging in clinical settings. However, HR was confirmed as a reliable parameter to assess MI engagement in PaS. Eye movements measured with the SE during MI did not resemble those during PE, which is presumably due to the demanding task. A re-evaluation with task adaptation is suggested.

Auto interpretable depth learning model to analyze the hemodynamic changes and pulmonary complications in laparoscopic gynecologic tumor surgery with nalmefene hydrochloride combined with general anesthesia.

In this work, based on intelligent computing, the biological signals of patients were analyzed to investigate the hemodynamic changes and pulmonary complications of Nalmefene Hcl combined with general anesthesia (GA) in laparoscopic gynecological tumor surgery (GTS). Eighty computer-aided GTS patients were randomly divided into a control group (n = 40) and an observation group (n = 40). Biomedical electrocardiogram (ECG) signals were detected by wavelet neural network in all patients undergoing laparoscopic gynecological tumor surgery and were computerized according to the android interface definition language model (AIDL). GA was used during surgery. The observation group was injected intravenously with 0.2 μg/kg naproxenacin hydrochloride after operation. The control group was given 1 mL 0.9% sodium chloride solution after operation. Mean arterial pressure (MAP), heart rate (HR), respiratory rate (RR), pulse oxygen saturation (SPO), coma score, and adverse reactions (AR) were compared between the two groups at 10, 20, and 30 minutes after wakefulness. The hemodynamic parameters between the two groups were compared. Serum urocholine (URO) and creatinine (Cre) levels were analyzed in patients without complications. ECG waveform based on wavelet neural network has a high recognition rate and strong generalization ability. 37 patients in the observation group recovered within 10 minutes after surgery, and the recovery rate at 30 minutes was 95%. 30 patients in the control group awoke 10 minutes after the operation, and the recovery rate at 30 minutes m-AR was 75%. The average abstract windows toolkit (AWT) of the observation group and control group was 11.87 ± 5.78 min and 16.46 ± 5.32 min, respectively, and the difference was significant (p < 0.05). There were significant differences in HR, systolic blood pressure (SBP), and diastolic blood pressure (DBP) between the observation group and the control group during the extubation (p < 0.05). Blood gas indexes PaO2, PvO2, PaCO2, and PvCO2 in the observation group were significantly different from those in the control group half an hour after the operation and half an hour after pneumoperitoneum (p > 0.05). Intelligent computational biological signal detection was beneficial to the development of surgery. Nalmefene Hcl combined with GA on the basis of the AIDL model has a significant effect on the awakening of GTS patients and can shorten sleep time. Patients with underlying cardiac disease were more likely to develop postoperative lung complications.

건강한 대상자에게 허혈성 전처치와 햄스트링 스트레칭, 복합적용이 운동능력에 미치는 즉각적인 효과비교

Purpose: This study aimed to examine the effects of ischemic preconditioning (IPC), hamstring stretching, and complex approach on exercise ability and to identify the impact on the ability to recover after exercise. Methods: A total of 20 healthy adult males were included in this study. All subjects performed different interventions before exercise (nothing applied [CON], IPC, hamstring stretching, and IPC + hamstring stretching [Complex]), followed by cycling exercise, with a 5-min rest after exercise. Heart rate (HR), rate of perceived exertion (RPE), and oxygen saturation (Spo2) were measured during exercise and 5 min after exercise. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) was measured before exercise, immediately after exercise, and 5 min after exercise. Data analysis was performed using one-way repeated measures analysis of variance. Results: Exercise time was significantly different between Complex and CON and IPC conditions. RPE measured during exercise was significantly different between Complex and CON and IPC conditions. A significant difference in HR measured during exercise was observed between Complex and CON conditions. However, no significant difference in SBP, DBP, HR, Spo2, and RPE measured 5 min after exercise was observed between the conditions. Conclusion: Applying IPC and hamstring stretching together before exercise can be a particularly effective method for improving aerobic exercise capacity.

Accuracy of closed-loop and open-loop propofol delivery systems by bispectral index monitoring in breast surgery patients: a prospective randomized trial

BackgroundThis randomized and controlled prospective study tested the hypothesis that closed-loop Target-Controlled Infusion (TCI) of propofol would be associated with better system performance when compared with open-loop controlled delivery of propofol. MethodsPatients scheduled for elective breast surgery were randomly assigned to two groups: a closed-loop group, in which propofol infusion was performed by a closed-loop TCI system that used the Bispectral Index (BIS) as a feedback parameter to titrate the rate of propofol infusion, and an open-loop group, in which propofol infusion was performed manually and guided by the bispectral index. ResultsA total of 156 patients were recruited for this study (closed-loop group n = 79; open-loop group n = 77). The Global Score (GS) of the closed-loop group was lower than that of the open-loop group (34.3 and 42.2) (p = 0.044). The proportions of time with a BIS value between 40 and 60 were almost identical in the closed-loop group and the open-loop group (68.7 ± 10.6% and 66.7 ± 13.3%) (p = 0.318). The individuals in the closed-loop group consumed more propofol compared with those in the open-loop group (7.20 ± 1.65 mg.kg−1.h−1 vs. 6.03 ± 1.31 mg.kg−1.h−1, p < 0.001). No intraoperative recall, somatic events or adverse events occurred. No significant difference in heart rate was observed between the two groups (p = 0.169). ConclusionThe closed-loop protocol was associated with lower BIS variability and lower out-of-range BIS values, at the cost of a greater consumption of propofol when compared to the open loop group. Register numberChiCTR-INR-17010399.

Comparison of volume-controlled and pressure-controlled ventilation during laryngeal mask airway anesthesia in cataract surgery

Introduction: Most patients undergoing eye surgery are elderly adults with underlying cardiovascular diseases. One of the complications during recovery is gastric insufflation, which can cause detrimental effects on cardiovascular patients. The present study compares two methods of volume-controlled ventilation (VCV) and pressure-controlled ventilation (PCV). Methods: The study enrolled 81 patients undergoing cataract surgery (41 in the PCV group and 40 in the VCV group). According to the American Society of Anaesthesiologists (ASA) classes I and II received general anaesthesia and laryngeal mask airway (LMA) ventilation using VCV or PCV. Maximum pressure (Ppeak), dynamic compliance, expiratory tidal volume, Spo2, non-invasive blood pressure, heart rate, and pain in the epigastrium and umbilical region were monitored at intervals of 1, 5, 10, and 20 minutes after the initiation of anaesthesia and the results of two groups were compared. Results: The means of Ppeak and tidal volume in the PCV group as well as the means of dynamic compliance and end-tidal carbon dioxide (EtCO2) in the VCV group were significantly high. The mean diastolic blood pressure was significantly different between two groups at 20th minute. There were no significant differences in heart rate, mean systolic blood pressure, arterial oxygen saturation, or abdominal pain between two study groups. Conclusion: VCV had a lower Ppeak and a higher dynamic compliance, but PCV had a larger tidal volume and lower EtCO2. There were no differences in terms of abdominal and umbilicus pain, as well as hemodynamic parameters, between two groups.

Comparison of nerve block anesthesia and local infiltration anesthesia with lidocaine hydrochloride in primary root canal treatment of mandibular molars

Purpose: To investigate and compare the analgesic effects of nerve block anesthesia and local infiltration anesthesia in one-visit root canal therapy of mandibular molars. &#x0D; Methods: A total of 120 patients who underwent one-visit root canal therapy for mandibular molars were divided into nerve block group (n = 76) and local infiltration group (n = 44). Lidocaine was used to anesthetize the two groups. Perioperative heart rate (HR), diastolic blood pressure (DBP) and systolic blood pressure (SBP) were determined in the two groups. Visual analogue scale (VAS) and Ramsay sedation scale were used to assess postoperative pain and sedation in the two groups. The occurrence of adverse reactions was also compared. &#x0D; Results: The success rate of the anesthesia in the nerve block group was significantly higher than that in local infiltration group (9 7.37 vs 88.64 %; p &lt; 0.05). There were no significant differences in HR, DBP and SBP levels between the two groups. Over time, VAS and Ramsay scores decreased in both groups, while the VAS and Ramsay scores in the nerve block group were significantly lower than those in the local infiltration group (p &lt; 0.05). The incidence of adverse reactions in the nerve block group was 5.26 %, which was not significantly different from 13.64 % incidence rate in local infiltration group (p &gt; 0.05). &#x0D; Conclusion: Both anesthesia methods have little effect on hemodynamics in patients undergoing one-visit root canal therapy for mandibular molars, but lidocaine nerve block anesthesia is more effective and has stronger analgesic and sedative effects than lidocaine local infiltration anesthesia.

A comparative study between I-gel and endotracheal tube in elective laparoscopic cholecystectomy surgeries under general anesthesia

Background: With increase in incidence of gall bladder stone the laparoscopic cholecystectomy preferred in various hospitals. Laryngoscopic stimulation of oropharyngeal and laryngeal structures leads to hemodynamic stress response. I-gel is a second generation supraglottic airway device with noninflatable cuff, having several advantages such as minimal hemodynamic changes during insertion and easy to insert. Aims and Objectives: The aim of this study was to compare I-gel and endotracheal tube regarding hemodynamic stability, adequacy of ventilation, ease of insertion through number of attempts, and time for insertion and associated complications in patients undergoing laparoscopic cholecystectomy. Materials and Methods: Total 60 patients of either sex, 25–55 years age of ASA Grades I and II were randomly allocated into two groups of 30 patients each; Group A (endotracheal tube) and Group B (I-gel). Ease of insertion in terms of number of attempts and time for insertion, hemodynamic variation and their complications were recorded. Results: Significantly less time was required for insertion of I-gel as compared to endotracheal tube (P=0.04), while number of attempts required for insertion were comparable, highly significant difference in heart rate, systolic blood pressure, mean arterial pressure just after insertion and at extubation of endotracheal tube than I-gel group (P&lt;0.01), peak airway pressure at insufflation with endotracheal tube was highly significant (P&lt;0.01), and SPO2 and ETCO2 were comparable. The complications were statistically insignificant among the study groups. Conclusion: Comparison to endotracheal tube, I-gel required less time and less number of attempts for insertion and causes fewer hemodynamic alterations. In addition, peak airway pressure was also significantly more in endotracheal tube just before and at pneumoperitoneum.

Comparing psychological and physiological factors involved in perceived threats in behaviorally inhibited individuals

Behavioral inhibition (BI) is a temperament characteristic which is associated with increased vulnerability to stress compared to non-behaviorally inhibited (NBI) counterparts. The physiologic and psychologic substrate which underlies the difference between BI and NBI individuals is unknown. Our previously published study demonstrated that BI individuals have decreased heart rate variability (HRV) relative to NBI individuals suggesting that BI individuals have less parasympathetic nervous system (PNS) output; however, it is unknown how BI affects perceived stress. Our current study tested the hypothesis that BI individuals would have higher perceived stress and physiologic stress during transdermal electrical stimulation (TES). Participants were administered TES beginning at 5mV and increased by 5mV increments until 100mV was reached. We used the Adult Measure of Behavioral Inhibition (AMBI) and the Perceived Stress Scale (PSS) to measure perceived stress, State-Trait Anxiety Inventory (STAI) scores to measure current stress, and a series of self-reported questionnaires to measure BI. Additionally, we used a BIOPAC data acquisition system to measure heart rate (HR), HRV, and blood pressure (BP) to measure physiological stress. Our pilot data suggests there was a non-significant trend of higher perceived stress after TES in BI individuals; however, there was a significant relationship between perceived stress and STAI scores. There was no significant difference in HR, HRV and BP between BI and NBI individuals. In conclusion, our pilot data suggests that a person’s BI or NBI status affects their perceived stress after a stressor is induced. BI individuals will have higher perceived stress after a stressor is presented as opposed to NBI individuals. We will conduct further studies using TES to further study this finding. Identification of these physiological factors could provide an additional mechanism for identifying individuals who are at a higher risk for developing stress and anxiety disorders. This is the full abstract presented at the American Physiology Summit 2023 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.

The Effects of Dietary Salt on Blood Pressure Variability, Cerebral Perfusion and Cognitive Function in Young-Adult Male Rats

Background: There is controversy about the relationship between dietary salt intake and cognitive function. Experimental studies showed that extremely high salt diets increased blood pressure (BP) levels, leading to cognitive impairment. However, extremely high salt diets are not clinically relevant. The present study examined how high dietary salt could affect cognitive function and whether these effects are via BP stability and cerebral hypoperfusion. Methods: SD rats (male, young adult) were on the control diet (0.4% NaCl), low salt diet (0.1% NaCl), or high salt diets (with three does at 1%, 2%, or 4% NaCl) for 12 weeks. BP levels, heart rate (HR), and BP variability (SD and CV) were measured repeatedly at baseline, 1, 2, 3, 4, 6, 8, and 12 weeks after the onset of the diet. Anxiety and cognitive function (open field, novel object recognition, and T-maze) were measured repeatedly at baseline, 4, 8, and 12 weeks after the onset of the diet. Blood Na+ and cerebral blood flow (CBF) were measured at the endpoint. Results: Rats with the low salt diet showed significantly reduced systolic BP (SBP) and diastolic BP (DBP) levels compared to those with the control diet and high salt diets at 8 weeks after the onset of the diet. Notably, rats with the low salt diet had the highest SBP variability (SBPV) and DBPV, while those with the control diet showed the lowest SBPV and DBPV. In high salt diet groups, SBPV and DBPV increased in a dose-dependent manner. There is no significant difference in HR between groups. Rats only with a 4% NaCl diet showed worse cognitive function compared to rats with low salt and control diet 8 weeks after the onset. Blood Na+ was similar between groups. Interestingly, the high salt diet increased the CBF in a dose-dependent manner. The CBF of the low salt diet was similar to those with 2% salt die, and the CBF of the control group was the lowest. Conclusions: This study suggests that a moderate-high salt diet would not affect cognitive function in young-adult male SD rats. Only consumption of an extremely high salt diet impaired cognitive function, and this harmful effect was not via cerebral hypoperfusion. Moreover, both low and high salt diets increased BPV. This research was funded by the START-UP FUNDING OF HANGZHOU NORMAL UNIVERSITY, grant number 4255C50221204123 (Dr. Fen Sun). This is the full abstract presented at the American Physiology Summit 2023 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.

102 Influence of localized massage on biobehavioral responses of mature horses during exposure to unfamiliar stimuli

Exposure to unfamiliar stimuli can lead to increased heart rate (HR), an increased incidence of locomotor behaviors, and changes in facial expressions. Responses of horses to unfamiliar stimuli can have important consequences for both horse and human safety. Horses preferentially groom conspecifics along the base of the neck, in front of the shoulder blade and across the withers. Imitated grooming of horses in this location has been shown to decrease horse HR. The objective of this study was to determine if localized massage along the base of the horse's neck and withers would influence HR, behavior, and facial expressions during exposure to an unfamiliar stimulus (cordless hair clippers) Eleven Quarter Horse mares (11.6 ± 4.9 yr) were fitted with a Polar H10 Equine HR monitor and led by the same handler to an open-front, 3.1 × 3.1 m grooming stall in a barn. After a 5 min acclimation period (P1: pre-stimulus), the clippers were turned on and held approximately 30.5 cm from the horse's left ear for a 3 min interval that consisted of: stimulus/pre-massage (45 s; P2), stimulus/massage (90 s; P3) and stimulus/post-massage (45 s; P4). The clippers were then turned off and the horse remained in the stall for 5 min (P5: post-stimulus). HR and video recording occurred throughout the 13 min session. Scan sampling of video footage every 15 s (P1 and P5) or every 5 s (P2-P4) was used to determine counts. Data wereanalyzed using PROC MIXED in SAS v. 9.4. Significant differences in HR, locomotor behaviors, and facial expressions were observed between horses in the study, highlighting the role of individual variation among horses. Although HR decreased once localized massage was initiated, no significant differences were observed in HR during exposure to the stimulus, with or without localized massage, compared with the pre- and post-stimulus periods. No differences were observed in the movement of horses’ front feet during exposure to the clippers; however, horses moved their hind feet more frequently during exposure to the clippers once the localized massage stopped (P < 0.05). Although the frequency of ears facing the same or different directions in a relaxed position was greater when localized massage was performed during exposure to the unfamiliar stimuli (P < 0.01), no differences were observed in nostril dilation, inner brow movements, or eye white increase during exposure to the stimuli compared with the pre- and post-stimulus periods. Localized massage may reduce stress-related behaviors during exposure of horses to unfamiliar stimuli; however, more research in this area is needed