Mean Heart Research Articles

Degree of PEGylatation of Lumbricus terrestris Hemoglobin Improves Microcirculatory Blood Flow but Increases the Rate of Auto-Oxidation.

The demand for red blood cells (RBCs) is on the rise due to the increasing diagnosis of chronic diseases such as sickle cell anemia, malaria, and thalassemia. Despite many commercial attempts, there are no U.S. FDA-approved artificial RBCs for use in humans. Existing RBC substitutes have employed various strategies to transport oxygen, extend the circulation time, and reduce organ toxicity, but none have replicated the natural protective mechanisms of RBCs, which prevent hemoglobin (Hb) dimerization and heme iron oxidation. Lumbricus terrestris (earthworm) erythrocruorin (LtEc) is a naturally occurring extracellular hemoglobin (Hb) with promising attributes: large molecular diameter (30 nm), high molecular weight (3.6 MDa), low auto-oxidation rate, and limited nitric oxide-scavenging properties. These characteristics make LtEc an ideal candidate as an RBC substitute. However, LtEc has a significant drawback, its short circulatory half-life. To address this issue, we explored thiol-mediated surface PEGylation of LtEc (PEG-LtEc) at varying polyethylene glycol (PEG) surface coverages. Increasing PEG surface coverage beyond 40% destabilizes LtEc into smaller subunits that are 1/12th the size of LtEc. Therefore, we evaluated two PEG surface coverage options: PEG-LtEc-0.2 (20% PEGylation) and PEG-LtEc-1.0 (100% PEGylation). We conducted experiments using golden Syrian hamsters with dorsal window chambers and catheters to assess the efficacy of these solutions. We measured microvascular parameters, organ function, cerebral blood flow, circulation time, mean arterial pressure, heart rate, and blood gases and performed histology to screen for toxicity. Our findings indicate that both PEG-LtEc molecules offer significant benefits in restoring microvascular parameters, organ function, cerebral blood flow, and circulation time compared to LtEc alone. Notably, PEG-LtEc-1.0 showed superior microvascular perfusion, although it exhibited a higher rate of auto-oxidation compared to PEG-LtEc-0.2. These results underscore the advantages of PEGylation in terms of tissue perfusion and organ health while highlighting its limitations.

The Physical and Physiological Demands of Intercounty Camogie During Competitive Match-Play.

Duggan, JD, Byrne, P, Malone, S, Cooper, S-M, and Moody, J. The physical and physiological demands of intercounty camogie during competitive match-play. J Strength Cond Res 38(9): e510-e520, 2024-The aim of this study was to determine the physical and physiological demands of intercounty camogie match-play between positions and halves of play. Data were collected from 28 players during 18 competitive games using global positioning systems (10-Hz) and heart rate monitors (2.4-GHz). The study demonstrated that intercounty camogie players covered a total distance (TD) (m ± SD) of 6,040 ± 628 m, relative distance (RD) of 83 ± 13 m·min-1, and maximum speed of 25 ± 1 km·h-1. Furthermore, the players covered a mean sprint distance of 214 ± 112 m and 14 ± 6 sprints. Players' mean heart rate (HRmean) and HRmax was 138 ± 23 b·min-1 and 164 ± 20 b·min-1, respectively. There were decrements between halves in TD (p < 0.01, ES = -0.45), RD (p < 0.01, ES = -0.45), maximum speed (p < 0.05, ES = -0.18), HRmax (p < 0.05, ES = -0.23), running (p < 0.01, ES = -0.34), high-speed running (p < 0.01, ES = 0.34), sprinting (p < 0.01, ES = -0.10), HRmax (p < 0.05, ES = -0.23), and HRmax % (p < 0.05, ES = -0.24). Midfielders covered a greater TD compared with full-forwards (p < 0.05, ES = -0.38) and half-forwards (p < 0.05, ES = -0.38). Full-backs covered a significantly lower RD than midfielders (p < 0.05, ES = -1.2), half-backs compared with full-forwards (p < 0.05, ES = 1.14), and half-forwards compared with full-forwards (p < 0.05, ES = 1.15). Full-forwards covered significantly less RD when compared with half-backs (p < 0.05, ES = -1.14), midfielders (p < 0.05, ES = -1.47), and half-forwards (p < 0.05, ES = -1.15). The findings provide physical and physiological values on the match demands of intercounty camogie match-play.

Using heart rate variability to evaluate the association between the autonomic nervous system and coagulation function in patients with endometrial cancer.

The incidence of endometrial cancer (EC) is increasing worldwide, but the specific mechanism of coagulation dysfunction in EC is not fully understood. The objective of the present study was to explore the relationship between autonomic nervous system function and coagulation function in patients with EC using heart rate variability (HRV) analysis. The study included 100 patients with EC who were treated at the Department of Gynecological Oncology of The First Affiliated Hospital of Bengbu Medical University (Bengbu, China) from December 2021 to March 2023. A 5-min resting electrocardiogram was collected from each patient to analyze HRV parameters, including the time domain parameters standard deviation of the normal-normal intervals (SDNN) and root mean square of successive interval differences (RMSSD), and the frequency domain parameters low-frequency power and high-frequency power (HF). Blood samples were submitted to biochemistry tests to measure coagulation markers, namely prothrombin time (PT), international normalized ratio of PT (PT-INR), prothrombin activity (PTA), activated partial thromboplastin time (APTT) and fibrinogen. Bivariate Spearman correlation analyses revealed that PT, PT-INR and APTT were significantly positively correlated with SDNN, RMSSD and HF, while PTA was significantly negatively correlated with RMSSD. Following adjustments for confounding factors, namely age, body mass index, menopause, ligation of the fallopian tubes, diabetes, hypertension, adjuvant chemotherapy and mean heart rate, linear regression analysis demonstrated that SDNN, RMSSD and HF were independent factors influencing PT and PT-INR in patients with EC. The findings of the present study indicate that certain HRV parameters correlate with coagulation markers in EC and provide new insight into the occurrence of cancer-associated coagulation dysfunction.

Comparing the Hemodynamic Effects of Intravenous and Volatile Anesthesia in Patients with End Stage Renal Disease Undergoing Laparoscopic Implantation of Peritoneal Dialysis Catheter in a Randomized Double-Blind Clinical Trial

Background: Due to the associated hypertension and cardiovascular disease in patients with ESRD hemodynamic changes during operations are detrimental and may be life-threatening. Therefore, hemodynamic stability is an important criterion in selecting the anesthetic approach. Methods: 72 ASA class III/IV, ESRD Patients were studied in randomized double blind clinical trial. They were divided into two groups by four-block randomization. A group of patients were induced and maintained by etomidate and second of patients were induced by Na thiopental and maintained by isoflurane. Systolic, diastolic and mean arterial blood pressure and heart rate were measured at interval of pre and post induction, postintubation, pre and post abdominal insufflation during and at the end of surgery and in recovery. The total BP modulators were recorded and postoperative nausea and vomiting was registered in the recovery. Data were analyzed by STATA version 12. Results: There was no significant difference in physical characteristics between two groups. There was no statistical difference between the groups in SBP and HR (P&gt;0.05), although DBP fluctuation&gt;20% at interval postinduction and prior to abdominal insufflation during surgery and at the end of surgery, was significantly higher in the isoflurane group of patients. (P=0.004, 0.001, 0.003 and 0.009, respectively). Also, the MAP fluctuation at interval of post induction, preinsufflation and at the end of surgery was significantly higher in isoflurane of patients. (P=0.04, 0.001, and 0.02, respectively). Conclusion: The group anesthetized with isoflurane had a higher hemodynamic fluctuation, compared to the group anesthetized with etomidate. As hemodynamic changes are critical in patients with ESRD, etomidate is a more appropriate anesthetic choice for implantation of peritoneal dialysis catheter by laparoscopic approach.

Medetomidine-vatinoxan-midazolam provides similar sedation depth with reduced bradycardia compared to dexmedetomidine-midazolam in pigeons (Columba livia domestica).

To determine if sedation with medetomidine-vatinoxan (Zenalpha; Dechra Veterinary Products) and midazolam (Alvogen) (ZM) would cause less cardiovascular depression and maintain similar depth and duration of sedation in pigeons (Columba livia domestica) compared to dexmedetomidine and midazolam (DM). In a blinded crossover study, 15 healthy adult domestic pigeons were sedated IM with either dexmedetomidine (0.08 mg/kg) and midazolam (2 mg/kg) or medetomidine (0.16 mg/kg), vatinoxan (3.2 mg/kg), and midazolam (2 mg/kg) from November through December 2023. Each subject was monitored for 60 minutes, then the sedation was reversed with atipamezole (0.8 mg/kg) and flumazenil (0.1 mg/kg) as needed. Sedation scores, heart rates, and respiratory rates were compared. There was no significant difference in the peak sedation score between DM and ZM groups, with both exhibiting median scores of 4 (heavy sedation). Mean heart rate was significantly higher for ZM than DM at 5, 10, 20, 30, 45, 60, and 65 minutes postinjection. Bradycardia occurred in both groups at 5 and 10 minutes postinjection and persisted for DM until reversal with atipamezole. Arrhythmias were auscultated in both groups. Bradypnea was not observed in either group, and all birds resumed normal behavior following recovery and the following day. Medetomidine-vatinoxan-midazolam provides a similar depth of sedation to DM but with less incidence of bradycardia. Further study is needed to determine the clinical applicability of this sedative in birds. Medetomidine-vatinoxan may be considered for short-term sedation and restraint in cardiovascularly stable pigeons.

Assessing the Analgesic Efficacy of Lumbosacral Epidural Morphine in Cats Undergoing Ovariohysterectomy: A Comparative Study of Two Doses.

Opioids are administered epidurally (PV) to provide trans- and postoperative analgesia. Twenty healthy female cats aged between 6 and 24 months and weighing between 2 and 3.7 kg, undergoing elective ovariohysterectomy (OVH), were induced with propofol (8 mg/kg), followed by continuous infusion (0.1-0.4 mg/kg/min). Three groups were defined: CG (0.1 mL/kg of iodinated contrast, n = 6), G0.1 (0.1 mg/kg of morphine, n = 7), and G0.2 (0.2 mg/kg of morphine, n = 7) per VP. All received 0.1 mL/kg of iodinated contrast per VP and injection water to obtain a total of 0.3 mL/kg. Heart rate (HR), systolic blood pressure (SBP), temperature, expired CO2, oxygen saturation, and number of rescue analgesics were monitored. Postoperatively, a multidimensional scale was used to assess acute pain in cats for 12 h. The mean HR and SBP in the CG were higher at the time of maximum noxious stimulation and required fentanyl in all groups. Postoperatively, 83%, 28%, and 7% of the animals in CG, G0.1, and G0.2, respectively, received rescue analgesia. In cats undergoing OVH, epidural morphine at doses of 0.1 and 0.2 mg/kg did not prevent the need for intraoperative rescue analgesia but reduced the postoperative analgesic needed.

Multifractal analysis of heart rate variability in pregnancy during sleep.

Understanding the complex dynamics of heart rate variability (HRV) during pregnancy is crucial for monitoring both maternal well-being and fetal health. In this study, we use the Multifractal Detrended Fluctuations Analysis approach to investigate HRV patterns in pregnant individuals during sleep based on RR interval maxima (MM fluctuations). In addition, we study the type of multifractality within MM fluctuations, that is, if it arises from a broad probability density function or from varying long-range correlations. Furthermore, to provide a comprehensive view of HRV changes during sleep in pregnancy, classical temporal and spectral HRV indices were calculated at quarterly intervals during sleep. Our study population consists of 21 recordings from nonpregnant women, 18 from the first trimester (early-pregnancy) and 18 from the second trimester (middle-pregnancy) of pregnancy. Results. There are statistically significant differences ( -value < 0.05) in mean heart rate, rms heart rate, mean MM fluctuations, and standard deviation of MM fluctuations, particularly in the third and fourth quarter of sleep between pregnant and non-pregnant states. In addition, the early-pregnancy group shows significant differences ( -value < 0.05) in spectral indices during the first and fourth quarter of sleep compared to the non-pregnancy group. Furthermore, the results of our research show striking similarities in the average multifractal structure of MM fluctuations between pregnant and non-pregnant states during normal sleep. These results highlight the influence of different long-range correlations within the MM fluctuations, which could be primarily associated with the emergence of sleep cycles on multifractality during sleep. Finally, we performed a separability analysis between groups using temporal and spectral HRV indices as features per sleep quarter. Employing only three features after Principal Component Analysis (PCA) to the original feature set, achieving complete separability among all groups appears feasible. Using multifractal analysis, our study provides a comprehensive understanding of the complex HRV patterns during pregnancy, which holds promise for maternal and fetal health monitoring. The separability analysis also provides valuable insights into the potential for group differentiation using simple measures such as mean heart rate, rms heart rate, and mean MM fluctuations or in the transformed feature space based on PCA.

Perioperative infusion of magnesium sulfate versus dexmedetomidine on the hemodynamic responses in patients undergoing laparoscopic cholecystectomy: A randomized controlled trial

Background: Laparoscopic cholecystectomy is associated with less post-operative pain, shorter hospitalization, and a faster functional recovery as compared to the open procedure. However, like any other surgery, a stress response is induced. Anesthesia interventions such as direct laryngoscopy, tracheal intubation, and extubation involve severe sympathetic stimulation. Magnesium can block the release of catecholamines from both the adrenal gland and adrenergic nerve terminals by inhibiting of activation of membrane Ca²⁺-ATPase and Na⁺-K⁺-ATPase. Aims and Objectives: Both magnesium sulfate and dexmedetomidine decrease the release of catecholamines and attenuate pressor responses to anesthesia and surgery. Materials and Methods: Eighty-four ASA I/II patients were randomly allocated to two groups. Group D received dexmedetomidine 1 μg/kg followed by 0.4 μg/kg/h and Group M received 2 g MgSO₄ followed by 15 mg/kg/h. hemodynamic variables were recorded as T0 (after loading dose of study drug), just before (T1) and 1, 2, and 3 min after ProSeal laryngeal mask airway (PLMA) insertion (T2 [i] [ii] [iii]), before and after peritoneal insufflation (T3 and T4), before and after table tilt (T5 and T6), after resuming flat position (T7), peritoneal deflation (T8), PLMA removal (T9), and on post-anesthesia care unit admission (T10). Data were collected and analyzed using SPSS 17 statistical software. Results: The demographic profile was comparable. After the study drug administration, there was a fall in mean arterial pressure (MAP) in both groups (Group D &gt; Group M) and no pressor response to PLMA insertion. At peritoneal insufflation, the MAP increase was significantly more in Group M at T6, T7, and T8 (31.9%, 27.9%, and 35.6% above baseline, respectively). Although there was a fall in systolic blood pressure (SBP) from the baseline throughout the procedure in both groups, SBP was significantly higher at most times in Group M as compared to Group D (P&lt;0.05). In both groups, there was a similar rise in diastolic blood pressure after peritoneal insufflation. The mean heart rate was significantly lower in Group D at all time points. Conclusion: Dexmedetomidine seemed to be superior to MgSO₄ for ameliorating hemodynamic responses in patients undergoing laparoscopic cholecystectomy.

Influence of static cartoons combined with dynamic virtual environments on preoperative anxiety of preschool-aged children undergoing surgery.

Preschoolers become anxious when they are about to undergo anesthesia and surgery, warranting the development of more appropriate and effective interventions. To explore the effect of static cartoons combined with dynamic virtual environments on preoperative anxiety and anesthesia induction compliance in preschool-aged children undergoing surgery. One hundred and sixteen preschool-aged children were selected and assigned to the drug (n = 37), intervention (n = 40), and control (n = 39) groups. All the children received routine preoperative checkups and nursing before being transferred to the preoperative preparation room on the day of the operation. The drug group received 0.5 mg/kg midazolam and the intervention group treatment consisting of static cartoons combined with dynamic virtual environments. The control group received no intervention. The modified Yale Preoperative Anxiety Scale was used to evaluate the children's anxiety level on the day before surgery (T0), before leaving the preoperative preparation room (T1), when entering the operating room (T2), and at anesthesia induction (T3). Compliance during anesthesia induction (T3) was evaluated using the Induction Compliance Checklist (ICC). Changes in mean arterial pressure (MAP), heart rate (HR), and respiratory rate (RR) were also recorded at each time point. The anxiety scores of the three groups increased variously at T1 and T2. At T3, both the drug and intervention groups had similar anxiety scores, both of which were lower than those in the control group. At T1 and T2, MAP, HR, and RR of the three groups increased. The drug and control groups had significantly higher MAP and RR than the intervention group at T2. At T3, the MAP, HR, and RR of the drug group decreased and were significantly lower than those in the control group but were comparable to those in the intervention group. Both the drug and intervention groups had similar ICC scores and duration of anesthesia induction (T3), both of which were higher than those of the control group. Combining static cartoons with dynamic virtual environments as effective as medication, specifically midazolam, in reducing preoperative anxiety and fear in preschool-aged children. This approach also improve their compliance during anesthesia induction and helped maintain their stable vital signs.

Comparison of the Magnesium Sulphate With Paracetamol Combination vs the Fentanyl With Lignocaine Combination in Attenuating the Hemodynamic Response During Laryngoscopy and Intubation: A Prospective, Double-Blinded Randomized Controlled Study.

Background and aims Laryngoscopy and intubation cause an increased sympatho-adrenergic pressor response, which can be detrimental to patients with coronary artery disease, hypertension, etc. Various drugs and manoeuvres have been triedto reduce the pressor response with acceptable results but the quest for the ideal drug still continues. Hence, we planned to compare the effects of magnesium sulfate with paracetamol and fentanyl with lignocaine on attenuating the hemodynamic responses due to direct laryngoscopy and intubation and to note the complications of these drugs. Methods We studied 60 adult patients of the American Society of Anaesthesiologists (ASA) physical status I and II of either sex, scheduled for elective surgery under general anaesthesia. The patients were randomly divided into two groups. Group A received 25 mg/kg magnesium sulphate mixed with paracetamol 1 gram IV (100 ml) given over 10 minutes before induction and Group B received 2 mcg/kg fentanyl and 1.5 mg/kg lignocaine, 3 minutes before intubation. All patients were uniformly pre-medicated, induced, and intubated as per standard protocol. Heart rate (HR) and systemic arterial pressures were recorded at baseline, after study drug infusion, after induction, and 1, 3, 5, 10, and 15 mins after intubation. Hemodynamic parameters were compared using repeated measures analysis of variance (ANOVA). In the post-hoc tests, p value < 0.05 was considered statistically significant. Results We observed the mean pre-op HR (p = 0.161) and mean HR one-minute post-induction (p = 0.144). The percentage change from baseline at one-minute post-induction was 9.7 in Group A and 15.2 in Group B. We observed the mean pre-op mean arterial pressure (MAP) (p = 0.119) and mean MAP one minute post-induction (p = 0.585). The percentage change from baseline at one-minute post-induction was 3.3 in Group A and 2.8 in Group B. The percentage change from baseline was found to be within 15%, for HR in Group A and for systolic blood pressure (SBP), diastolic blood pressure (DBP), and MAP in Group B. However, there was no statistically significant difference (p > 0.05) between the mean HR, SBP, DBP, and MAP between the time points. Conclusion In our study, both the combinations of drugs, magnesium sulphate with paracetamol (Group A drugs) and fentanyl with lignocaine (Group B drugs) were found to be equally effective (i.e. neither group was superior to the other) in attenuating the hemodynamic response to laryngoscopy and intubation.

Predicting Workers' Stress: Application of a High-Performance Algorithm Using Working-Style Characteristics.

Work characteristics, such as teleworking rate, have been studied in relation to stress. However, the use of work-related data to improve a high-performance stress prediction model that suits an individual's lifestyle has not been evaluated. This study aims to develop a novel, high-performance algorithm to predict an employee's stress among a group of employees with similar working characteristics. This prospective observational study evaluated participants' responses to web‑based questionnaires, including attendance records and data collected using a wearable device. Data spanning 12 weeks (between January 17, 2022, and April 10, 2022) were collected from 194 Shionogi Group employees. Participants wore the Fitbit Charge 4 wearable device, which collected data on daily sleep, activity, and heart rate. Daily work shift data included details of working hours. Weekly questionnaire responses included the K6 questionnaire for depression/anxiety, a behavioral questionnaire, and the number of days lunch was missed. The proposed prediction model used a neighborhood cluster (N=20) with working-style characteristics similar to those of the prediction target person. Data from the previous week predicted stress levels the following week. Three models were compared by selecting appropriate training data: (1) single model, (2) proposed method 1, and (3) proposed method 2. Shapley Additive Explanations (SHAP) were calculated for the top 10 extracted features from the Extreme Gradient Boosting (XGBoost) model to evaluate the amount and contribution direction categorized by teleworking rates (mean): low: <0.2 (more than 4 days/week in office), middle: 0.2 to <0.6 (2 to 4 days/week in office), and high: ≥0.6 (less than 2 days/week in office). Data from 190 participants were used, with a teleworking rate ranging from 0% to 79%. The area under the curve (AUC) of the proposed method 2 was 0.84 (true positive vs false positive: 0.77 vs 0.26). Among participants with low teleworking rates, most features extracted were related to sleep, followed by activity and work. Among participants with high teleworking rates, most features were related to activity, followed by sleep and work. SHAP analysis showed that for participants with high teleworking rates, skipping lunch, working more/less than scheduled, higher fluctuations in heart rate, and lower mean sleep duration contributed to stress. In participants with low teleworking rates, coming too early or late to work (before/after 9 AM), a higher/lower than mean heart rate, lower fluctuations in heart rate, and burning more/fewer calories than normal contributed to stress. Forming a neighborhood cluster with similar working styles based on teleworking rates and using it as training data improved the prediction performance. The validity of the neighborhood cluster approach is indicated by differences in the contributing features and their contribution directions among teleworking levels. UMIN UMIN000046394; https://www.umin.ac.jp/ctr/index.htm.

Acute effects of blood flow restricted aerobic exercise in type 2 diabetes mellitus.

This study aimed to compare the acute effects of aerobic exercise performed with blood flow restriction (BFR), a novel method to increase exercise gains, with blood free flow (BFF) conditions in type 2 diabetes mellitus (T2DM). Fifteen individuals with T2DM performed BFF and BFR (40% of arterial occlusion pressure) cycling exercises 48 hours apart, at equal intensity (45% heart rate reserve) and duration (38 minutes). Systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), blood glucose, heart rate, and muscle oxygen saturation (SmO2) were assessed before-after and during exercise sessions. SBP, DBP, and MAP in the overload phase were higher in the BFR group than in the BFF group (P = .009, 0.031, and 0.013, respectively). Changes in blood pressure (∆SBP and ∆DBP) were similar between the BFF and BFR groups (P > .05), whereas ∆MAP differed (P = .016). Changes in blood glucose levels and heart rates were not significantly different between the groups. Although SmO2baseline was lower in the BFR group (P = .049), SmO2min and SmO2max did not differ significantly between the BFF and BFR groups. The similar decrease in blood glucose levels between the groups suggests that BFR exercise is favorable in terms of hypoglycemia. The higher blood pressure observed during the BFR exercise remained within safe limits. These results suggest that people with T2DM can safely perform BFR aerobic exercises; however, further studies are required.

Cardiovascular effects of dog appeasing pheromone in the hospital environment

Recent research has emphasized the health implications of acute or chronic stress in animals. Hospitalized dogs are susceptible to stress due to various factors, including exposure to a novel environment, invasive procedures, and separation from their primary caregiver. The clinical significance of stress in these animals underscores the importance of stress management from the moment of admission. However, there remains a lack of universal qualitative and quantitative indicators of stress in small animals, necessitating reliance on behavioral analysis and stress marker assessment for accurate diagnosis. Among these markers, cardiovascular parameters such as heart rate and systolic blood pressure are commonly used, although their interpretation can be influenced by various factors. The aim of the study was to assess the impact of appeasing pheromone on cardiovascular parameters in hospitalized dogs. Ten healthy dogs were selected for a prospective, paired, randomized, and double-blinded. The dogs were submitted to two experimental protocols: pheromone administration and placebo. The cardiovascular parameters were evaluated at baseline until the end of a 24-hour hospitalization period. The study evaluated ambulatory electrocardiography and systolic non-invasive blood pressure using a doppler. Analysis of cardiovascular parameters revealed no significant difference in systolic blood pressure between groups, despite its elevation in both treatment conditions. In the placebo group, the maximum heart rate of the placebo group at time baseline (T0) was lower compared to subsequent time points (T6, T12, T20), indicative of stress upon arrival in the hospital environment. Conversely, the pheromone group showed a higher mean heart rate at T20 compared to the placebo group. Additionally, the placebo group displayed a higher minimum heart rate at time baseline (T0) compared to later time points (T6, T12, T20, T24). At time T6, a higher minimum heart rate was observed in the pheromone group. Even though fluctuations were observed in mean and minimum heart rates during monitoring, they indicated no clinically relevant deviations. There was no difference in heart rate variability over time between the analyzed substances. Exposure to dog appeasing pheromone through a diffuser presentation, therefore, did not lead to significant changes in cardiovascular parameters related to stress reduction in hospitalized dogs.

Impact of Exercise Heat Acclimation on Performance in Hot, Cool and Hypoxic Conditions

PurposeThe aim of this study was to confirm the impact of heat acclimation on aerobic performance in hot conditions and elucidate the transfer of heat adaptations to cool and hypoxic environments.MethodsTen males (VO2peak: 4.50 ± 0.50 L/min) completed two three-week interventions consisting of heat acclimation (HA: 36°C and 59% RH) and temperate training (TEMP: 18°C and 60% RH) in a counter-balanced crossover design. Training weeks consisted of four work-matched controlled heart rate sessions interspersed with one intermittent sprint session, and two rest days. Before and after the interventions VO2peak and 20-min time trial performance were evaluated in COOL (18°C), HOT (35°C) and hypoxic (HYP: 18°C and FiO2: 15.4%) conditions.ResultsFollowing HA, VO2peak increased significantly in HOT (0.24 L/min [0.01, 0.47], P = 0.040) but not COOL (P = 0.431) or HYP (P = 0.411), whereas TEMP had no influence on VO2peak (P ≥ 0.424). Mean time trial power output increased significantly in HOT (20 W [11, 28], P < 0.001) and COOL (12 W [4, 21], P = 0.004), but not HYP (7 W [−1, 16], P = 0.075) after HA, whereas TEMP had no influence on mean power output (P ≥ 0.110). Rectal (−0.13°C [−0.23, −0.03], P = 0.009) and skin (−0.7°C [−1.2, −0.3], P < 0.001) temperature were lower during the time trial in HOT after HA, whereas mean heart rate did not differ (P = 0.339).ConclusionsHA improved aerobic performance in HOT in conjunction with lower thermal strain and enhanced cardiovascular stability (similar heart rate for higher workload), whereas the mechanistic pathways improving performance in COOL and HYP remain unclear.

The effect of central sleep apnea on sleep architecture in children with obstructive sleep apnea

ObjectiveThis study aimed to investigate how central sleep apnea (CSA) impacts sleep patterns in children with obstructive sleep apnea (OSA). MethodsChildren undergoing polysomnography (PSG) were enrolled and sorted into two groups: those with OSA alone (Group A) and those with both OSA and CSA (CAI <1 nd: children with 10 % CSA or more and less than 50 %, Group B). Statistical analysis was conducted to compare sleep structure and clinical features between Group A and Group B. ResultsGroup B exhibited significantly higher respiratory events, apnea hypoventilation index, apnea index and oxygen desaturation index (ODI) compared to Group A (p < 0.05). Group B also showed higher total sleep time and arousal index than Group A (P < 0.05). The proportion of time spent in stage N3 was lower in Group B than in Group A (P < 0.05). Moreover, mean heart rate and minimum heart rate were higher in Group B compared to Group A (P < 0.05).Minimum oxygenation levels (including non-rapid eye movement (NREM) stages) were lowe in Group B than in Group A (P < 0.05). Additionally, the prevalence of positional obstructive sleep apnea (P-OSA) was greater in Group B than in Group A (P < 0.05). ConclusionIn comparison to those with OSA alone, children with OSA and concurrent CSA exhibited distinct sleep patterns, including reduced N3uration, higher arousal index, longer respiratory events, higher ODI, and lower oxygen saturation, higher heart rate.

Coping with emotional pain: An experimental comparison of acceptance vs. avoidance coping

The present study compared multi-methodically and multi-dimensionally the effects of acceptance and avoidance coping with emotional pain, both between and within-group. Convenience sampling was used, with 88 participants included (81.8% females; Mage = 21.75 years) and being randomly assigned to one of two instructed groups: (a) Acceptance followed by avoidance of pain sensations and thoughts, and (b) Avoidance followed by acceptance. All participants underwent an emotional pain induction procedure three times involving negative autobiographical recall and an emotional-pain standardized script. In the first emotion induction, no instructions were given whereas in the other two, participants were instructed to use the techniques they were trained in. On both autobiographical and emotional-pain script tasks, participants who used firstly avoidance and secondly acceptance exhibited significantly lower mean heart rate and higher mean heart rate variability RR index across time. Also, in the last emotional pain induction, on both tasks, acceptance resulted in lower physiological activation than avoidance. No significant differences were found for the self-report of negative affect. Overall, acceptance vs. avoidance differences were mostly found in the physiological outcomes, suggesting the importance of including objective measures when examining coping techniques. Our findings suggest that ACT's concept of creative hopelessness is supported, as participants may have to use firstly use ineffective coping strategies to better understand what methods are most effective for managing pain. To our knowledge, this study is the first study to compare acceptance vs. avoidance coping with emotional pain both between and within-group, using a multi-method and multi-dimensional approach.

Effectiveness of different doses of dexmedetomidine on intraoperative haemodynamic profiles and postoperative pain in patients undergoing abdominal surgery at Dilla University Referral Hospital, Ethiopia, 2024: a double-blind randomized controlled trial.

Abdominal surgery stands as one of the most frequently conducted procedures across surgical specialties, accounting for up to half of surgery-related expenses. Hemodynamic instability emerges as a significant concern during anaesthesia and surgery, provoked by the stress of intubation, surgical incision, and anaesthetic agents. Following abdominal surgery, pain is an inevitable consequence, typically managed with opioid-based analgesia. However, the adverse effects associated with opioids often overshadow their analgesic benefits, particularly in the context of abdominal surgery. Consequently, there exists a necessity to explore and assess alternative non-opioid pain management options post-abdominal surgery as part of a broader strategy to reduce opioid usage. The primary aim of this investigation is to assess the effectiveness of varying doses of dexmedetomidine in regulating intraoperative hemodynamics and alleviating postoperative pain in patients undergoing abdominal surgery. Ethical clearance and institutional review board were obtained from the ethical clearance committee of Dilla University College of Medicine and Health Sciences with protocol unique number of duirb/008/22-01. Our trial has been prospectively registered on the Pan African Clinical Trial Registry with a unique identification number for the registry PACTR202208813896934. Statistical package and analysis were performed by using SPSS version 25. The distribution of data was checked by using Shapiro-Wilk test and the homogeneity of variance was checked by Levene's test. Analysis of variance (ANOVA) and Kruskal-Wallis H test were used for normally distributed continuous data and non-normally distributed or non-parametric data, respectively. P value less than 0.05 with a power of 90% was considered statistically significant. There was a statistically significant increase in mean SBP in the control group at the different critical time points (P<0.05), as compared to the baseline value, while there was no significant difference in mean systolic blood pressure (SBP) between the baseline and all other levels for group 2 and group 3. A statistically significant increase in mean arterial pressure (MAP) was detected in the control group at immediately after intubation (P=0.009) as compared to the baseline value, while a statistically significant reduction in mean heart rate (HR) was observed in group 3 at 15th min after infusion and at 30th 30 min after induction compared to baseline with a P value of 0.002 and 0.008, respectively.Conclusion:Perioperative low-dose infusion of dexmedetomidine at the rate of 0.4mcg/kg/h is a useful anaesthesia adjuvant to control hemodynamic stress response to critical periods. It is wise to use this infusion dose as part of general anaesthesia to achieve better hemodynamic stability.

Seasonal Changes in Match Demands and Workload Distribution in Collegiate Soccer Across Two Seasons.

Floersch, S, Vidden, C, Askow, AT, Jones, MT, Fields, JB, and Jagim, AR. Seasonal changes in match demands and workload distribution in collegiate soccer across two seasons. J Strength Cond Res 38(8): 1440-1446, 2024-The purpose of this study was to examine seasonal changes in match demands in a collegiate women's soccer team. Forty-eight NCAA Division III women soccer athletes (age: 19.5 ± 1.2 years; height: 1.67 ± 0.05 m; body mass: 64.8 ± 7.4 kg; fat-free mass: 50.0 ± 4.5 kg; body fat %: 22.6 ± 6.0) were equipped with wearable global positioning systems with inertial sensors and heart rate (HR) monitors during matches throughout the 2019 (n = 22) and 2021 seasons (n = 26). Players were classified by position: flank player (FP; n = 28), center midfielder (CM; n = 11), and center back fielder (CB; n = 9) and as starters (S, n = 17) or reserves (R, n = 31). Variables included HR, training load, total distance, high-speed distance, distance per minute, and weighted distance. Differences in match and practice session demands were analyzed using linear mixed-effects models with season (2 levels; 2019 and 2021) as a fixed factor, with alpha set to p = 0.05. Data across all matches and training sessions were collapsed and presented as mean ± SD for descriptive purposes and then grouped by session type (i.e., match or training) and position. Athletes traveled more distance at high speeds during match play in the 2021 season compared with 2019 (mean difference, 95% confidence intervals [CI]) (200, 95% CI: 104, 304 km; p < 0.05) but had a lower training load in 2021 compared with 2019 (-50, 95% CI: -63, -36; p < 0.05) during match play. For training sessions, mean HR (4, 95% CI: 2, 5 bpm), total distance (0.5, 95% CI: 0.4, 0.7), distance per minute (5.6, 95% CI: 4.5, 6.7 m·min-1), high-speed distance (43, 95% CI: 43, 18, 67 m), high accelerations (8.6, 95% CI: 5.4, 11.8 n), and high accelerations per minute (0.1, 95% CI: 0.1, 0.1 n·min-1) were all higher in 2021 compared with 2019 (p < 0.05). As a team, several differences in measures of external workload were found between seasons in both session types (training and matches). Variations in positional demands of match play appear to fluctuate by year.

A Four-dimensional Computed Tomography Generated Internal Target Volume Approach to Paediatric High Risk Neuroblastoma to Reduce Organ at Risk and Normal Tissue Irradiation

AimsThe magnitude of upper abdominal organ motion in children may be overestimated by current planning target volumes (PTV). A four-dimensional computed tomography (4DCT) – derived internal target volume (ITV) is frequently used in adult radiotherapy to take respiratory-related organ motion into account. In this study, the dosimetric consequences for target coverage and organs at risk from the use of an ITV approach compared to standard PTV margins in children with high-risk neuroblastoma were investigated. Materials and methods14 patients, median age 4.1 years, range 1.5 – 18.9 years, (9 midline targets, 5 lateralised) each had two dual arc volumetric modulated arc therapy (VMAT) plans (14 ×1.5 Gy) generated. One used an ITV-approach; motion information derived from 4DCT (PTV_itv) with a 5mm ITV to PTV expansion, and the other a PTV margin of 10mm from CTV to PTV (PTV_standard). Differences in absolute PTV volume and organ at risk doses are described. ResultsThe ITV approach resulted in a highly significant reduction in PTV size of 38% (p<0.0001). For midline targets, an ITV approach resulted in a small but statistically significant reduction in combined mean kidney dose of 0.8Gy, p 0.01. Mean heart and lung dose were reduced by an average of 1 Gy with an ITV approach. Non-PTV integral dose from 30.4 Gy L to 27.8 Gy L using an ITV approach. ConclusionAn ITV-approach to respiratory related organ motion management in children can significantly reduce absolute PTV volumes, maintain target coverage and reduce dose delivered to normal tissue in proximity to the target. This is an essential step to maximising the benefits of highly conformal radiotherapy techniques including VMAT for this patient group, and in the future with Proton Therapy.

Topical larynx lidocaine Spraying reduces cardiovascular stress response caused by suspension laryngoscopic surgery

ObjectiveThis study aimed to investigate the potential reduction of cardiovascular stress response caused by suspension laryngoscopic surgery through the application of lidocaine spray on the larynx and trachea. MethodsA total of 68 patients scheduled for elective suspension laryngoscopic surgery were randomly assigned to either the lidocaine group (Group L, n = 34) or the control group (Group C, n = 33). In Group L, patients received a sprayed lidocaine dose of 2 mg/kg on the larynx and trachea after anesthesia induction, prior to intubation. In Group C, equal volumes of saline solution were administered. MAP and HR were recorded at various time points: before anesthesia (T0), 1-minute after intubation (T1), 1 and 3 min after suspension laryngoscopy (T2 and T3), at the end of the operation (T4), and at 1, 5, and 30 min after extubation (T5, T6, and T7). Arterial blood glucose, epinephrine, and norepinephrine levels were measured at T0, T2, T5, and T7. The occurrence of severe cough and sore throat at T6 and T7 after extubation was compared between the two groups. ResultsAt T0 and T1, there were no statistically significant differences in mean arterial pressures, heart rate, and blood catecholamine levels between the two groups. However, from T2 to T7, the blood pressure and heart rate in Group L were lower compared to Group C, with significant differences observed at T2‒T6 (p < 0.05). Group L also showed less elevation in blood glucose at T2, T5, and T7 (p < 0.05). The changes in epinephrine and norepinephrine levels between the two groups were statistically significant at T2 and T5 (p < 0.05). ConclusionsAdministering lidocaine spray on the larynx and trachea during intubation for suspension laryngoscopic surgery can effectively alleviate the stress response. Level 1 evidencePatients in this study are randomly assigned to the treatment or control group and are followed prospectively.