Effects of Cold Stimulation on Cardiac-Vagal Activation in Healthy Participants: Randomized Controlled Trial

Acceptability and Perceived Utility of Virtual Reality Among People Who Are Incarcerated Who Use Drugs

People who are incarcerated are at heightened risk of overdose upon community reentry. Virtual reality (VR) may provide an innovative tool for overdose prevention intervention in corrections facilities. This mixed methods study sought to understand incarcerated individuals' perspectives on VR for overdose prevention and explore physiological arousal associated with use of VR equipment. Study participants were 20 individuals, stratified by gender, with an opioid use disorder at a county jail. Qualitative interviews assessed acceptability and perceived utility of VR in the jail setting. Thematic analysis indicated high levels of acceptability and potential utility in the following areas: (a) mental health and substance use interventions, (b) community reentry skills training, and (c) communication and conflict resolution skills. Heart rate variability (HRV) data were collected continuously during the interview and during VR exposure to explore whether exposure to the VR environment provoked arousal. Physiological data analyses showed a significant decrease in heart rate (HR) [b = -3.14, t(18) = -3.85, p < .01] and no arousal as measured by root mean square of successive RR interval differences (RMSSD) [b = -0.06, t(18) = -1.06, p = .30] and high frequency-HRV (HF-HRV) [b = -0.21, t(18) = -1.71, p = .10]. This study demonstrated high acceptability and decreased HR response of VR among incarcerated people who use drugs.

The Effect of Cold Application to the Lateral Neck Area on Peripheral Vascular Access Pain: A Randomised Controlled Study

INTRODUCTION

Various types of vagus nerve stimulation are employed in the treatment of a range of conditions, including depression, anxiety, epilepsy, headache, tinnitus, atrial fibrillation, schizophrenia, and musculoskeletal pain. The objective of this study was to apply vagal stimulation to the neck area using standardised cold, and then analyse the level of vascular access discomfort experienced by individuals who underwent venous cannulation from the dorsal side of the hand prior to anaesthesia.

MATERIALS AND METHODS

A total of 180 patients, aged 18-75, who were scheduled to undergo elective surgery, were categorised into three distinct groups: the Sham group (Group S), the Control group (Group K), and the Cold group (Group M), with each group consisting of 60 individuals. Bilateral cold application to the lateral side of the neck was performed prior to the commencement of vascular access in Group M patients, followed by the subsequent opening of vascular access. The alterations in heart rate among patients was assessed subsequent to the application of cold and following the establishment of vascular access. The participants were instructed to assess their level of vascular access pain on a numerical pain scale (NRS) ranging from 0 to 10.

RESULTS

A statistically significant difference (p = 0.035) was seen when comparing the pain ratings of patients during vascular access. The study revealed that the NRS values exhibited a statistically significant decrease in Group M compared to both Group K (p = 0.038) and Group S (p = 0.048). Group M had a higher prevalence of individuals experiencing mild pain compared to other groups, and the difference was statistically significant (p = 0.029). In Group M, the average heart rate following vagal stimulation exhibited a statistically significant decrease compared to the average heart rate observed at the beginning of the study (p < 0.05). Upon comparing the original heart rate measurements with the heart rate values following vascular access, it was observed that there was an elevation in heart rate for both Group S and Group K. Conversely, Group M exhibited a decrease in heart rate after vascular access when compared to the initial heart rate values.

CONCLUSIONS

In the present investigation, it was discovered that the application of cold to the neck region resulted in a drop in heart rate among the patients, which persisted throughout the process of vascular access. Furthermore, the level of pain experienced by these individuals was reduced during vascular access procedures.

A nationwide analysis of the outcomes in hospitalized patients with atrial fibrillation and temperature-related illnesses

OBJECTIVES

The authors evaluated mortality and indices of cost of care among inpatients with Atrial Fibrillation (AF) and a diagnosis of a Temperature-Related Illness (TRI). The authors also assessed trends in the prevalence of TRIs among AF hospitalizations.

METHODS

In this cross-sectional study, the authors used discharge data from the Nationwide Inpatient Sample (NIS) collected between January 2005 and September 2015 to identify patients with a diagnosis of AF and TRI. Outcomes of interest included in-hospital mortality, invasive mechanical ventilation, hospital length of stay, and cost of hospitalization.

RESULTS

A total of 37,933 encounters were included. The median age was 79 years. Males were slightly overrepresented relative to females (54.2% vs. 45.8%, respectively). Although Blacks were only 6.6% of the cohort, they represented 12.2% of the TRI cases. Compared to non-TRI-related hospitalizations, a diagnosis of a TRI was associated with an increased likelihood of invasive mechanical ventilation (16.5% vs. 4.1%, p < 0.001), longer length-of-stay (5 vs. 4 days, p < 0.001), higher cost of care (10,082 vs. 8,607, in US dollars p < 0.001), and increased mortality (18.6% vs. 5.1%, p < 0.001). Compared to non-TRI, cold-related illness portends higher odds of mortality 4.68, 95% Confidence Interval (4.35-5.04), p < 0.001, and heat-related illness was associated with less odds of mortality, but this was not statistically significant 0.77 (0.57-1.03), p = 0.88.

CONCLUSION

The occurrence of TRI among hospitalized AF patients is small but there is an increasing trend in the prevalence, which more than doubled over the decade in this study. Individuals with AF who are admitted with a TRI face significantly poorer outcomes than those admitted without a TRI including higher mortality. Cold-related illness is associated with higher odds of mortality. Further research is required to elucidate the pathogenic mechanisms underlying these findings and identify strategies to prevent TRIs in AF patients.

The Newborn Infant Parasympathetic Evaluation (NIPE™) monitor predicts post-operative pain in children undergoing day-procedures: A prospective observational study

BACKGROUND

Pain assessment is essential for the administration of appropriate analgesia. Currently, clinicians use surrogate methods, such as heart rate or behavioural pain scales, to estimate pain in neonates and infants. The Newborn and Infant Parasympathetic Evaluation (NIPE™) monitor aims to provide an objective numeric value (NIPE index) of pain through a continuous assessment of the patient's parasympathetic activity. The aim of this study was to determine if the intraoperative NIPE index monitoring could predict postoperative pain in neonates and infants.

METHODS

This prospective observational pilot study included neonates and infants undergoing elective day-surgical procedures (n = 50). Intraoperatively, NIPE indices at 0 (NIPE0), 10 (NIPE10), 20 (NIPE20), 30 (NIPE30) minutes and at completion of surgery (NIPEe), were recorded; the median NIPE index (NIPEm) was calculated for the entire procedure. Postoperative Face, Legs, Activity, Cry, Consolability (FLACC) scale scores were calculated by the nursing staff blinded to the intraoperative NIPE indices.

RESULTS

Linear regression documented an association between the NIPEm and postoperative FLACC score at 0 (r = 0.31, p = 0.03) and 10 min (r = 0.36, p = 0.01). No significant associations were observed for FLACC scores at 20 (r = 0.21, p = 0.2) and 30 min (r = 0.36, p > 0.9). Multiple regression analysis revealed that intraoperative NIPE10, NIPE20, NIPE30 and NIPEe also predicted the FLACC score at 0 min (p = 0.003).

CONCLUSION

The intraoperative NIPE index is predictive of pain in the immediate postoperative period. This association was lost at 20 min likely due to nursing intervention to administer analgesia. NIPE monitoring could be useful in facilitating postoperative pain management in infants.

LEVEL OF EVIDENCE

II.

TYPE OF STUDY

Study of Diagnostic Test.

Relationship between anxiety and monotonous task performance in response to local cooling: an experimental study in healthy young men

There are limited studies on monotonous task performance and its relationship with anxiety and stress traits. This study aimed to determine if local cooling exerts physiological effects and positively affects task performance. Ten male participants performed monotonous work for 24 min under control and local cooling conditions. We measured physiological arousal and anxiety using electroencephalography and the State-Trait Anxiety Inventory, respectively. The participants rated their drowsiness, the thermal sensation of the seat and whole-body thermal sensation. Despite the lack of significant differences in physiological arousal, the state anxiety score, which reflects the current stressful situation, was significantly lower in the local cooling condition. Therefore, cooling might help relieve stress during monotonous tasks, without impairing task performance. In addition, individuals with higher state anxiety scores tended to experience a faster increase in their arousal level. Thus, individual anxiety traits may modulate attentional resources during monotonous task performance.Practitioner summary: The study on topic related to monotonous task performance and its relationship with anxiety and stress traits is novel. Minimising negative emotions is key to monotonous task execution under stress. Individual anxiety might modulate resource allocation for monotonous task execution.

No effect of repeated post-resistance exercise cold or hot water immersion on in-season body composition and performance responses in academy rugby players: a randomised controlled cross-over design

PURPOSE

Following resistance exercise, uncertainty exists as to whether the regular application of cold water immersion attenuates lean muscle mass increases in athletes. The effects of repeated post-resistance exercise cold versus hot water immersion on body composition and neuromuscular jump performance responses in athletes were investigated.

METHODS

Male, academy Super Rugby players (n = 18, 19.9 ± 1.5 y, 1.85 ± 0.06 m, 98.3 ± 10.7 kg) participated in a 12-week (4-week × 3-intervention, i.e., control [CON], cold [CWI] or hot [HWI] water immersion) resistance exercise programme, utilising a randomised cross-over pre-post-design. Body composition measures were collected using dual-energy X-ray absorptiometry prior to commencement and every fourth week thereafter. Neuromuscular squat (SJ) and counter-movement jump (CMJ) performance were measured weekly. Linear mixed-effects models were used to analyse main (treatment, time) and interaction effects.

RESULTS

There were no changes in lean (p = 0.960) nor fat mass (p = 0.801) between interventions. CON (p = 0.004) and CWI (p = 0.003) increased (g = 0.08-0.19) SJ height, compared to HWI. There were no changes in CMJ height (p = 0.482) between interventions.

CONCLUSION

Repeated post-resistance exercise whole-body CWI or HWI does not attenuate (nor promote) increases in lean muscle mass in athletes. Post-resistance exercise CON or CWI results in trivial increases in SJ height, compared to HWI. During an in-season competition phase, our data support the continued use of post-resistance exercise whole-body CWI by athletes as a recovery strategy which does not attenuate body composition increases in lean muscle mass, while promoting trivial increases in neuromuscular concentric-only squat jump performance.

Topical Neck Cooling Without Systemic Hypothermia Attenuates Myocardial Ischemic Injury and Post-ischemic Reperfusion Injury

Background

Following acute myocardial infarction (MI), irreversible damage to the myocardium can only be reduced by shortening the duration between symptom onset and revascularization. While systemic hypothermia has shown promising results in slowing pre-revascularization myocardial damage, it is resource intensive and not conducive to prehospital initiation. We hypothesized that topical neck cooling (NC), an easily implemented therapy for en route transfer to definitive therapy, could similarly attenuate myocardial ischemia-reperfusion injury (IRI).

Methods

Using an in vivo mouse model of myocardial IRI, moderate systemic hypothermia or NC was applied following left coronary artery (LCA) occlusion and subsequent reperfusion, at early, late, and post-reperfusion intervals. Vagotomy was performed after late NC in an additional group. Hearts were harvested to measure infarct size.

Results

Both hypothermia treatments equally attenuated myocardial infarct size by 60% compared to control. The infarct-sparing effect of NC was temperature-dependent and timing-dependent. Vagotomy at the gastroesophageal junction abolished the infarct-sparing effect of late NC. Cardiac perfusate isolated following ischemia had significantly reduced cardiac troponin T, HMGB1, cell-free DNA, and interferon α and β levels after NC.

Conclusions

Topical neck cooling attenuates myocardial IRI in a vagus nerve-dependent manner, with an effect comparable to that of systemic hypothermia. NC attenuated infarct size when applied during ischemia, with earlier initiation resulting in superior infarct sparing. This novel therapy exerts a cardioprotective effect without requiring significant change in core temperature and may be a promising practical strategy to attenuate myocardial damage while patients await definitive revascularization.

Heart rate variability, thyroid hormone concentration, and neuropsychological responses in Brazilian navy divers: a case report of diving in Antarctic freezing waters

Open-water diving in a polar environment is a psychophysiological challenge to the human organism. We evaluated the effect of short-term diving (i.e., 10 min) in Antarctic waters on autonomic cardiac control, thyroid hormone concentration, body temperatures, mood, and neuropsychological responses (working memory and sleepiness). Data collection was carried out at baseline, before, and after diving in four individuals divided into the supporting (n=2) and diving (n=2) groups. In the latter group, autonomic cardiac control (by measuring heart rate variability) was also assessed during diving. Diving decreased thyroid-stimulating hormone (effect size = 1.6) and thyroxine (effect size = 2.1) concentrations; these responses were not observed for the supporting group. Diving also reduced both the parasympathetic (effect size = 2.6) and sympathetic activities to the heart (ES > 3.0). Besides, diving reduced auricular (effect size > 3.0), skin [i.e., hand (effect size = 1.2) and face (effect size = 1.5)] temperatures compared to pre-dive and reduced sleepiness state (effect size = 1.3) compared to basal, without changing performance in the working memory test. In conclusion, short-term diving in icy waters affects the hypothalamic-pituitary-thyroid axis, modulates autonomic cardiac control, and reduces body temperature, which seems to decrease sleepiness.

Topical Neck Cooling Prolongs Survival of Rats with Intra-Abdominal Feculent Sepsis by Activation of the Vagus Nerve

Global hypothermia prolongs survival in rats with intraabdominal feculent sepsis by inhibiting inflammatory responses. We hypothesized that topical neck cooling (TNC) has similar benefits. Septic shock was induced by cecal ligation and incision (CLI) in Sprague Dawley rats. Rats were randomized to sham laparotomy, control with CLI, CLI with TNC, or vagotomy at the gastroesophageal junction before CLI and TNC. Two more groups underwent peritoneal washout with and without TNC two hours after CLI. TNC significantly lowered neck skin temperature (16.7 ± 1.4 vs. 30.5 ± 0.6 °C, p < 0.05) while maintaining core body normothermia. TNC rats recovered from anesthesia 70 min earlier than the control (p < 0.05). Three hours following CLI, the control and vagotomy with TNC groups had significantly more splenic contraction, fewer circulating leukocytes and higher plasma IL-1β, IL-10 and TNF-α levels than TNC rats (p < 0.05). TNC prolonged survival duration after CLI by a median of four hours vs. control (p < 0.05), but no benefit was seen if vagotomy preceded TNC. Peritoneal washout alone increased survival by 3 h (9.2 (7.8–10.5) h). Survival duration increased dramatically with TNC preceding washout, to a 56% survival rate (>10 days). TNC significantly prolonged the survival of rats with severe intraabdominal sepsis by inhibiting systemic proinflammatory responses by activating vagal anti-inflammatory pathways.