The effects of oral contraceptives on resting autonomic function and the autonomic response to physiological stressors: a systematic review

PURPOSE

This systematic review aimed to summarize how oral contraceptives (OC) affect resting autonomic function and the autonomic response to a variety of physiological stressors.

METHODS

A search strategy was created to retrieve citations investigating physiological responses comparing OC users to non-users (NOC) in response to autonomic reflex activation.

RESULTS

A total of 6148 citations were identified across databases from inception to June 2, 2022, and 3870 citations were screened at the abstract level after deduplication. Then, 133 texts were assessed at full-text level, and only 40 studies met eligibility requirements. Included citations were grouped by the aspect of autonomic function assessed, including autonomic reflex (i.e., baroreflex, chemoreflex, mechanoreflex, metaboreflex, and venoarterial reflex), or indicators (i.e., heart rate variability, pulse wave velocity, and sympathetic electrodermal activity), and physiological stressors that may alter autonomic function (i.e., auditory, exercise, mental or orthostatic stress, altitude, cold pressor test, sweat test, and vasodilatory infusions).

CONCLUSION

OC influence the physiological responses to chemoreflex, mechanoreflex, and metaboreflex activation. In terms of autonomic indices and physiological stressors, there are more inconsistencies within the OC literature, which may be due to estrogen dosage within the OC formulation (i.e., heart rate variability) or the intensity of the stressor (exercise intensity/duration or orthostatic stress). Further research is required to elucidate the effects of OC on these aspects of autonomic function because of the relatively small amount of available research. Furthermore, researchers should more clearly define or stratify OC use by duration, dose, and/or hormone cycling to further elucidate the effects of OC.

Can postexercise hypotension also be observed in African and Asian populations: a systematic review and meta-analysis of randomized controlled trials

Worldwide, raised blood pressure (BP) or hypertension is the global leading risk factor for the development of cardiovascular diseases and all-cause mortality, with the highest prevalence found in Asian and African origin populations. Post-exercise hypotension (PEH), defined as a sustained reduction in BP after a single bout of exercise is an important physiological phenomenon in BP management. However, little is known about the hypotensive effect of a single bout of exercise in non-Caucasian populations. We systematically summarized the acute effects of a single bout of aerobic exercise on BP in a population of African or Asian origin. We searched the MEDLINE database identifying randomized controlled trials investigating the effect of a single bout of aerobic exercise on BP in African or Asian populations with optimal BP, high normal BP or hypertension published in a peer reviewed journal up to August 2021. A subsequent meta-analysis was performed using random-effect models fitted to estimate effect sizes. We identified 10 aerobic exercise trials performed in individuals of Asian origin (n = 136; mean age: 29.51 (21.2-69) years: 78% male; baseline systolic BP/diastolic BP: 118.9 ± 9.64/68.9 ± 2.69 mmHg) and 11 aerobic exercise trials involving individuals of African origin (n = 157; mean age: 41.05 (29.9-49) years; 59% male; baseline systolic BP/diastolic BP: 134.5 ± 8.65 mmHg/82.2 ± 3.24 mmHg). Non-significant reductions in office systolic BP and diastolic BP at 30 min post exercise (-2.25 [-6.38, 1.88] mmHg, p = 0.28/-1.02 [-2.51, 0.47] mmHg, p = 0.18) and 60 min post exercise (-2.80 [-7.90, 2.28], p = 0.27/-1.95, [-5.66, 1.75], p = 0.3) were observed compared to the control intervention. No statistically significant differences were found between both ethnic groups (p > 0.05). Ambulatory BP was reported only in a few African groups. No effect was found on 24h-systolic BP post exercise, but 24h-diastolic BP was statistically significantly reduced (-1.89 [-3.47, -0.31] mmHg, p < 0.01) after a bout of aerobic exercise compared to the control intervention. The available evidence is insufficient to recommend a single session of aerobic exercise as an efficient tool to lower BP in African and Asian populations. Though, the paucity of data in non-Caucasian populations underscores the need for additional efforts to establish the efficacy of single bouts of exercise, including isometric and dynamic resistance exercise, as a potential non-pharmacological adjunct to help lowering BP in the daily life of descendants of Asian or African origin.

Mechanisms maintaining cerebral perfusion during systemic hypotension are impaired in elderly adults

Postural hypotension abruptly lowers cerebral perfusion, producing unsteadiness which worsens with aging. This study addressed the hypothesis that maintenance of cerebral perfusion weakens in the elderly due to less effective cerebrovascular autoregulation and systemic cardiovascular responses to hypotension. In healthy elderly (n = 13, 68 ± 1 years) and young (n = 13, 26 ± 1 years) adults, systemic hypotension was induced by rapid deflation of bilateral thigh cuffs after 3-min suprasystolic occlusion, while heart rate (HR), mean arterial pressure (MAP), and blood flow velocity of the middle cerebral artery (VMCA) were recorded. VMCA/MAP indexed cerebrovascular conductance (CVC). Durations and rates of recovery of MAP and VMCA from their respective postdeflation nadirs were compared between the groups. Thigh-cuff deflation elicited similar hypotension and cerebral hypoperfusion in the elderly and young adults. However, the time elapsed (TΔ) from cuff deflation to the nadirs of MAP and VMCA, and the time for full recovery (TR) from nadirs to baselines were significantly prolonged in the elderly subjects. The response rates of HR (ΔHR, i.e. cardiac factor), MAP (ΔMAP, i.e. vasomotor factor), and CVC following cuff deflation were significantly slower in the elderly. Collectively, the response rates of the cardiac, vasomotor, and CVC factors largely explained TRVMCA. However, the TRVMCA/ΔMAP slope (-3.0 ± 0.9) was steeper (P = 0.046) than the TRVMCA/ΔHR slope (-1.1 ± 0.4). The TRVMCA/ΔCVC slope (-2.4 ± 0.6) was greater (P = 0.072) than the TRVMCA/ΔHR slope, but did not differ from the TRVMCA/ΔMAP slope (P = 0.52). Both cerebrovascular autoregulatory and systemic mechanisms contributed to cerebral perfusion recovery during systemic hypotension, and the vasomotor factor was predominant over the cardiac factor. Recovery from cerebral hypoperfusion was slower in the elderly adults because of the age-diminished rates of the CVC response and cardiovascular reflex regulation. Systemic vasoconstriction predominated over increased HR for restoring cerebral perfusion after abrupt onset of systemic hypotension.

Changes in respiratory mechanics in response to crystalloid infusions in extremely premature infants

Extremely premature infants are at a higher risk of developing respiratory distress syndrome and circulatory impairments in the first few weeks of life. Administration of normal saline boluses to manage hypotension is a common practice in preterm infants. As a crystalloid, a substantial proportion might leak into the interstitium; most consequently the lungs in the preterm cohorts, putatively affecting ventilation. We downloaded and analyzed ventilator mechanics data in infants managed by conventional mechanical ventilation and administered normal saline bolus for clinical reasons. Data were downloaded for 30 min prebolus, 60 min during the bolus followed by 30 min postbolus. Sixteen infants (mean gestational age 25.2 ± 1 wk and birth weight 620 ± 60 g) were administered 10 mL/kg normal saline over 60 min. The most common clinical indication for saline was hypotension. No significant increase was noted in mean blood pressure after the saline bolus. A significant reduction in pulmonary compliance (mL/cmH2O/kg) was noted (0.43 ± 0.07 vs. 0.38 ± 0.07 vs. 0.33 ± 0.07, P = 0.003, ANOVA). This was accompanied by an elevation in the required peak inspiratory pressure to deliver set volume-guarantee (19 ± 2 vs. 22 ± 2 vs. 22 ± 3 mmHg, P < 0.0001, ANOVA), resulting in a higher respiratory severity score. Normal saline infusion therapy was associated with adverse pulmonary mechanics. Relevant pathophysiologic mechanisms might include translocation of fluid across pulmonary capillaries affected by low vascular tone and heightened permeability in extremes of prematurity, back-pressure effects from raised left atrial volume due to immature left-ventricular myocardium; complemented by the effect of cytokine release from positive pressure ventilation.NEW & NOTEWORTHY Administration of saline boluses is common in premature infants although hypovolemia is an uncommon underlying cause of hypotension. This crystalloid can redistribute into pulmonary interstitial space. In the presence of an immature myocardium and diastolic dysfunction, excess fluid can also be "edemagenic." This study on extremely premature infants (25 wk gestation) noted adverse influence on respiratory physiology after saline infusion. Clinicians need to choose judiciously and reconsider routine use of saline boluses in premature infants.

Large-scale real-world data analysis of source plasma collections using a novel technology-enabled nomogram

BACKGROUND

Source plasma collections are needed to satisfy the growing demand for plasma-derived medicinal products. The US plasma collection target volume has been guided by a standard weight-based FDA-issued nomogram (STAN) since 1992. In this research, large-scale US-based real-world data (RWD) were analyzed to confirm the safety and volume gains of a newly introduced personalized nomogram (PERS) that was previously studied in a premarket randomized controlled environment.

STUDY DESIGN AND METHODS

A non-inferiority (NI) analysis was conducted to compare the novel nomogram's significant hypotensive adverse event (AE) incidence rate with large historical standard nomogram AE datasets. Additionally, the average target volumes and donor return rates were compared for collections following PERS and STAN.

RESULTS

A total of 4,816,784 donations (PERS) by 414,957 donors resulted in a rate of 0.0998% (95% CI [0.0970, 0.1027]) significant hypotensive AEs. NI analysis suggested strong non-inferiority of the new technology (Δ = -0.0082%, 95% CI [-0.0113, -0.0050], prespecified NI margin = 0.1080). Average plasma collection target volumes increased by 66.39 mL (8.49%; p < .0001). Consecutive weekly donor return rates were consistent between the two nomograms (PERS: 73.6%, 95% CI [69.6%-76.7%]; STAN: 74.1%, 95% CI [66.1%-77.2%]).

DISCUSSION

This analysis confirms in a large-scale real-world dataset the key safety parameter and collection benefit of a novel, technology-enabled nomogram. The nomogram may help meet the growing demand for plasma-derived therapies by providing approximately 8.5% more plasma per donation on average while maintaining donor safety and return rates.

Detailed Assessment of the "I Need Help" Criteria in Patients With Heart Failure: Insights From the HELP-HF Registry

BACKGROUND

The "I Need Help" markers have been proposed to identify patients with advanced heart failure (HF). We evaluated the prognostic impact of these markers on clinical outcomes in a real-world, contemporary, multicenter HF population.

METHODS

We included consecutive patients with HF and at least 1 high-risk "I Need Help" marker from 4 centers. The impact of the cumulative number of "I Need Help" criteria and that of each individual "I Need Help" criterion was evaluated. The primary end point was the composite of all-cause mortality or first HF hospitalization.

RESULTS

Among 1149 patients enrolled, the majority had 2 (30.9%) or 3 (22.6%) "I Need Help" criteria. A higher cumulative number of "I Need Help" criteria was independently associated with a higher risk of the primary end point (adjusted hazard ratio for each criterion increase, 1.19 [95% CI, 1.11-1.27]; P<0.001), and patients with >5 criteria had the worst prognosis. Need of inotropes, persistently high New York Heart Association classes III and IV or natriuretic peptides, end-organ dysfunction, >1 HF hospitalization in the last year, persisting fluid overload or escalating diuretics, and low blood pressure were the individual criteria independently associated with a higher risk of the primary end point.

CONCLUSIONS

In our HF population, a higher number of "I Need Help" criteria was associated with a worse prognosis. The individual criteria with an independent impact on mortality or HF hospitalization were need of inotropes, New York Heart Association class or natriuretic peptides, end-organ dysfunction, multiple HF hospitalizations, persisting edema or escalating diuretics, and low blood pressure.

Inhibition of bradykinin in SARS-CoV-2 infection: a randomised, double-blind trial of icatibant compared with placebo (ICASARS)

SARS-CoV-2 binds to ACE2 receptors and enters cells. The symptoms are cough, breathlessness, loss of taste/smell and X-ray evidence of infiltrates on chest imaging initially caused by oedema, and subsequently by a lymphocytic pneumonitis. Coagulopathy, thrombosis and hypotension occur. Worse disease occurs with age, obesity, ischaemic heart disease, hypertension and diabetes.These features may be due to abnormal activation of the contact system. This triggers coagulation and the kallikrein-kinin system, leading to accumulation of bradykinin and its derivatives, which act on receptors B1R and B2R. Receptor activation causes cough, hypotension, oedema and release of the cytokine interleukin-6 (IL-6) which recruits lymphocytes. These effects are core features seen in early SARS CoV-2 infection.

METHODS AND ANALYSIS

In this study, hypoxic patients with COVID-19 with symptom onset ≤7 days will be randomised to either a bradykinin inhibitor (icatibant) or placebo. Patients and investigators will be blinded. The primary outcome will be blood oxygenation, measured by arterial blood sampling. The secondary outcome will be cardiovascular status. Retinal imaging will be performed to assess vessel size. Blood samples will be taken for measurement of inflammatory analyses including IL-6. As a separate substudy, we will also take comparator blood inflammatory samples from a COVID-19-negative cohort.

ETHICS AND DISSEMINATION

The study has received the following approvals: West Midlands-Edgbaston Research Ethics Committee. Medicines and Healthcare products Regulatory Agency has issued a clinical trial authorisation. Belfast Health and Social Care Trust is the study sponsor. Results will be made available to participants upon request and findings will be presented and published.

TRIAL REGISTRATION NUMBER

NCT05407597.

Impact of Opioid-Free Anesthesia on Postoperative Quality of Recovery in Patients After Laparoscopic Cholecystectomy-A Randomized Controlled Trial

Purpose

Opioid analgesics may delay discharge and affect postoperative quality of recovery because of their significant adverse effects, such as hyperalgesia, postoperative nausea and vomiting (PONV), shivering and urine retention. We aimed to compare the quality of postoperative recovery (QoR) between patients undergoing laparoscopic cholecystectomy surgeries with opioid-free anesthesia (OFA) and those with opioid-based anesthesia (OA).

Patients and Methods

80 adult patients undergoing laparoscopic cholecystectomy were randomly allocated to an opioid-free anesthesia group (Group OFA) or an opioid-based anesthesia group (Group OA). The primary outcome was the quality of postoperative recovery using QoR-15 scale on postoperative day 1 (POD 1) and 2 (POD 2). The secondary outcomes included the incidence of opioid-related adverse symptoms, perioperative hemodynamic data, duration of post-anesthesia care unit (PACU) stay and duration of extubation, and the incidences of hypotension and bradycardia.

Results

A statistically significant difference in total QoR-15 was observed between the two groups on POD 1 and POD 2 (91.00 (90.00, 92.00) vs 113.00 (108.25, 115.00), 106.00 (104.00, 112.00) vs 133.00 (130.00, 135.00), P < 0.001). The incidence of opioid-related symptoms was significantly different between the two groups on POD 1 (P < 0.05). There were between-group differences in systolic blood pressure (SBP) and diastolic blood pressure (DBP) at T3 (P < 0.001). There was also a significant difference in the incidence of hypotension between the two groups (P = 0.001). However, there were no significant differences in the duration of PACU stay, duration of extubation and the incidence of bradycardia (P > 0.05). There was no difference in heart rate between the two groups at all observed time points, either (P > 0.05).

Conclusion

We concluded that the quality of recovery of patients receiving OFA was superior to those receiving OA after laparoscopic cholecystectomy.

Comparison of the hemodynamic changes between preeclamptic and normotensive parturients who underwent cesarean section under spinal anesthesia at North Showa zone public hospitals, Oromia region, Ethiopia, 2022: a prospective cohort study

BACKGROUND

Spinal anaesthesia complicates maternal hemodynamic and may expose the parturient to dangerous cardiovascular problems. Up to 7% to 89.2% of pregnant women can suffer from spinal anaesthesia-related hypotension. The aim of this study to compare the hemodynamic changes between preeclamptic and normotensive parturients who underwent caesarean section under spinal anaesthesia at North Showa Zone Public Hospitals, Oromia Region, from February 15 to May 15, 2022.

METHODS

A prospective cohort study was conducted on a total of 140 parturients (70 in each group) who underwent cesarean delivery under spinal anesthesia. The study participants were chosen using a consecutive sampling technique. Data were collected from patient charts and intraoperative observations and entered into the Epi Data software version 4.6 and exported to the Statistical Package for the Social Sciences version 25 software. Hemodynamic change = (baseline value-current value/baseline value) * 100. The independent t-test, Mann-Whitney U test, two ways mixed ANOVA, chi-square, and Fisher's exact test was used to analyze the data as appropriate. A P < 0.05 was statistically significant.

RESULTS

The mean percentage change in SBP, DBP, and MAP after spinal anaesthesia was a statistically significant difference between the normotensive and preeclamptic groups, except MAP at 15 min was comparable between the two groups with p = 0.638. The proportion of preeclamptic parturients who develop hypotension was 47%, compared to 74% of normotensive parturients, and the RR of developing hypotension, if participants were preeclamptic, was 0.63, with a 95% confidence interval of 0.412 to 0.978 and a p = 0.039. The mean change in heart rate during the first 15 min was comparable between the groups.

CONCLUSION

In contrast to normotensive parturients undergoing caesarean section under spinal anaesthesia, our study found that the hemodynamic change was lower in preeclamptic parturients. The proportion of preeclamptic women who develop hypotension was 47%, compared to 74% of normotensive parturients.

Anticholinergic Toxidrome as a Possible Explanation for Methylene Blue Toxicity

BACKGROUND Methylene blue has multiple uses in medicine. It is generally used to treat refractory vasoplegia and methemoglobin toxicity, and can be used as a dye to localize the parathyroid glands intra-operatively. In refractory vasoplegia, methylene blue inhibits endothelial nitric oxide and guanylate cyclase, causing vasoconstriction and potentially stabilizing blood pressure. Multiple complications have been associated with the use of methylene blue. These are related to either the sole effect of methylene blue or the combined effect of methylene blue and certain antidepressants, such as selective serotonin reuptake inhibitors (SSRIs). To the best of our knowledge, in the setting of post-cardiac surgery vasoplegia, there have been no reports of the neurological toxicity of methylene blue in the absence of SSRI use. In this case report, we describe the anticholinergic manifestations associated with the use of methylene blue in post-cardiac surgery vasoplegia. CASE REPORT A male patient in his mid-sixties with severe mitral regurgitation underwent elective mitral valve replacement. Postoperatively, he was hypotensive and required a high dose of vasopressors. Methylene blue was administered to treat refractory vasoplegia. The patient became anuric and febrile, with bilateral mydriasis. Internal cooling and continuous renal replacement therapy were initiated, and symptoms rapidly resolved. The patient was discharged after prolonged hospitalization with a permanent catheter for hemodialysis. CONCLUSIONS Anticholinergic toxidrome may explain the neurological adverse effects associated with high doses of methylene blue. Physicians should be cautious when using methylene blue in combination with other anticholinergic drugs and in conditions of renal failure. The development of methylene blue toxicity warrants the urgent discontinuation of the agent and early drug elimination.

Chronic red laser treatment induces hypotensive effect in two-kidney one-clip model of renovascular hypertension in rat

To evaluate whether the chronic effect of photobiomodulation therapy (PBM) on systolic arterial pressure (SAP) from two kidneys one clip (2 K-1C) hypertension animal models can cause a hypotensive effect. Serum levels of nitric oxide were also analyzed and the assessment of lipid peroxidation of the thoracic aorta artery. Male Wistar rats were used. Hypertensive animals (2 K-1C) with Systolic arterial pressure (SAP) greater than or equal to 160 mmHg were used. Systolic arterial pressure (SAP) was determined by the tail plethysmography technique. Normotensive (2 K) and hypertensive (2 K-1C) rats were treated to PBM for 4 weeks using a laser whose irradiation parameters were: red wavelength (λ) = 660 nm: operating continuously; 56 s per point (3 points) spot size = 0.0295 cm2; average optical power of 100 mW; energy of 5.6 J per point; irradiance of 3.40 W/cm2; fluency of 190 J/cm2 per point. The application was on the animals tails, at 3 different points simultaneously, in contact with the skin. To assess serum nitrite and nitrate (NOx) levels, blood collection was performed after chronic PBM treatment, 24 h after the last laser application. The evaluation of the lipid peroxidation of the thoracic aorta artery was performed by measuring the concentration of hydroperoxide by the FOX method. Chronic photobiomodulation therapy (PBM) by red laser (660 nm) can induce a hypotensive effect in 64% of 2 K-1C hypertensive animals, which we say responsive animals. There was no difference in serum NO levels 24 h after the last red laser application, between treated and non-treated groups. Aortic rings from 2 K-1C hypertensive animals present a higher lipid peroxidation. The chronic PBM treatment by red laser decreased aortic rings lipid peroxidation in hypertensive responsive groups, compared to control. our results indicate that chronic PBM made by red laser has an important hypotensive effect in renovascular hypertensive models, by a mechanism that involves decrease in oxidative stress from vascular beds.

Implementation of a Consensus-Driven Quality Improvement Protocol to Decrease Length of Stay after Elective Carotid Endarterectomy

BACKGROUND

National guidelines stipulate that postoperative length-of-stay (LOS) after elective carotid endarterectomy (CEA) should not exceed 1 day on average, yet perioperative care coordination gaps may limit the ability for institutions to achieve this goal. Internal review determined that increased LOS after CEA at our institution was frequently attributable to urinary retention or postoperative hypertension. We designed and implemented a quality improvement (QI) protocol aiming to better our institutional performance in postoperative LOS after CEA, consisting of 2 Plan-Do-Study-Act (PDSA) cycles.

METHODS

In the first PDSA cycle, a division-wide standardized protocol was developed by which antihypertensive medications were managed preoperatively and through postoperative day (POD) 1. This protocol included dedicated patient outreach with instructions for at-home antihypertensive management through the morning of POD 0. Second, alpha-1-blockade was administered to all male patients preoperatively. All patients receiving an elective CEA performed at our institution by vascular surgeons were included in the protocol. The primary outcome measure was defined percent failure of the LOS >1 day metric, with raw LOS as a secondary outcome measure. Process measures included adherence to the antihypertensive medication protocol and adherence to preoperative alpha-1 blockade. Balance measures included documented intraoperative hypotension and 30-day readmission. Fisher's exact test was used to evaluate relationships between preintervention and postintervention cohorts and the outcome measure. Wilcoxon rank-sum tests were used to evaluate relationships between cohorts and total LOS.

RESULTS

Baseline performance on the LOS >1 day metric after elective CEA was 58.3% in the 8 months prior to intervention, across 48 patients. Both PDSA interventions were implemented simultaneously. In the 12 months after intervention, 64 patients met protocol inclusion criteria, including 19 symptomatic patients (29.7%). Process measure success for preoperative antihypertensive regimen adherence was 89.8%. For males not chronically prescribed alpha-1 blockade preoperatively, process measure success for adherence to preoperative alpha-1 blockade was 78.8%. The intraoperative hypotension balance measure occurred in 1 patient (1.6%). Performance on the LOS >1 day outcome measure was improved to 32.8% (P = 0.01). Performance on the raw LOS outcome measure was similar between the preintervention cohort (median 2 days, interquartile range [IQR] 1-2) and postintervention cohort (median 1 day, IQR 1-2, P = 0.07). Performance on the 30-day readmission balance measure was similar between preintervention (6.3%) and postintervention cohorts (9.4%, P = 0.73).

CONCLUSIONS

The consensus-driven development and implementation of a QI protocol to reduce postoperative LOS after CEA showed promising results in our institution, with approximately 40% improvement in the primary outcome measure. Wider efforts to improve LOS after CEA should include a focus on minimization of postoperative hypertension and urinary retention.

The Effect of Fluid Resuscitation Timing in Early Sepsis Resuscitation

PURPOSE

The dose and timing of early fluid resuscitation in sepsis remains a debated topic. The objective of this study is to evaluate the effect of fluid timing in early sepsis management on mortality and other clinical outcomes.

METHODS

Single-center, retrospective cohort study of emergency-department-treated adults (>18 years, n = 1032) presenting with severe sepsis or septic shock. Logistic regression evaluating the impact of 30 mL/kg crystalloids timing and mortality-versus-time plot controlling for mortality in emergency department sepsis score, lactate, antibiotic timing, obesity, sex, systemic inflammatory response syndrome criteria, hypotension, and heart and renal failures. This study is a subanalysis of a previously published investigation.

RESULTS

Mortality was 17.1% (n = 176) overall and 20.4% (n = 133 of 653) among those in septic shock. 30 mL/kg was given to 16.9%, 32.2%, 16.2%, 14.5%, and 20.3% of patients within ≤1, 1 ≤ 3, 3 ≤ 6, 6 ≤ 24, and not reached within 24 h, respectively. A 24-h plot of adjusted mortality versus time did not reach significance, but within the first 12 h, the linear function showed a per-hour mortality increase (odds ratio [OR] 1.29, 95% confidence interval [CI] 1.02-1.67) which peaks around 5h, although the quadratic function does not reach significance (P = .09). When compared to patients receiving 30 mL/kg within 1 h, increased mortality was observed when not reached within 24 h (OR 2.69, 95% CI 1.37-5.37) but no difference when receiving this volume between 1 and 3 (OR 1.11, 95% CI 0.62-2.01), 3 and 6 (OR 1.83, 95% CI 0.97-3.52), or 6 and 24 h (OR 1.51, 95% CI 0.75-3.06). Receiving 30 mL/kg between 1 and 3 versus <1 h increased the incidence of delayed hypotension (OR 1.83, 95% CI 1.23-2.72) but did not impact need for intubation, intensive care unit admission, or vasopressors.

CONCLUSIONS

We observed weak evidence that supports that earlier is better for survival when reaching fluid goals of 30 mL/kg, but benefits may wane at later time points. These findings should be viewed as hypothesis generating.

The preventive effect of 5-hydroxytryptamine-3 receptor antagonist on blood pressure reduction and postoperative nausea and vomiting during general anesthesia induction: A double-blinded, randomized controlled trial

STUDY OBJECTIVE

Administering a 5-hydroxytryptamine-3 receptor (5-HT3) at anesthesia induction may aid in achieving hemodynamic stability during general anesthesia induced using opioids. Therefore, we aimed to evaluate the effect of ramosetron, a 5-HT3 antagonist, administered on hypotension at the induction of total intravenous anesthesia (TIVA) with propofol and remifentanil. Additionally, we aimed to compare the impact of ramosetron administration at anesthesia induction versus that at the end of the surgery on postoperative nausea and vomiting (PONV).

DESIGN

Patients were randomly allocated to the Induction group (administration of ramosetron [0.3 mg/5 ml] at anesthesia induction and normal saline [5 ml] at the end of the surgery) or End group (administration of normal saline [5 ml] at anesthesia induction and ramosetron [0.3 mg/5 ml] at the end of the surgery). Hemodynamic status, PONV, and postoperative pain were assessed.

SETTING

Operating room, post-anesthetic care unit, and general ward.

PATIENTS

In total, 176 non-smoking patients without any past medical history undergoing laparoscopic gynecological surgeries under TIVA were included in the study.

MEASUREMENTS

Blood pressure (BP), heart rate, PONV, visual analog scale (VAS).

MAIN RESULTS

The Induction group exhibited significantly higher BP at anesthesia induction and required significantly lower doses of phenylephrine and ephedrine during anesthesia than the End group had. However, PONV and postoperative pain were similar between the two groups.

CONCLUSIONS

Administering ramosetron at anesthesia induction resulted in significantly better hemodynamic stability with significantly lesser requirement of phenylephrine and ephedrine than administering at the end of the surgery did. Therefore, we recommend ramosetron administration at anesthesia induction rather than at the end of the surgery to prevent PONV and the decrease in the mean BP during TIVA with propofol and remifentanil.

Aging in females is associated with changes in respiratory modulation of sympathetic nerve activity and blood pressure

Sympathetic nerve activity (SNA) is tightly coupled with the respiratory cycle. In healthy human males, respiratory modulation of SNA does not change with age. However, it is unclear how this modulation is affected by age in females. We investigated whether respiratory sympathetic modulation is altered in healthy postmenopausal (PMF) versus premenopausal female (YF), and younger male (YM) adults, and determined its relationship to resting blood pressure. Muscle SNA (MSNA; microneurography), respiration (transducer belt), ECG, and continuous blood pressure were measured in 12 YF, 13 PMF, and 12 YM healthy volunteers. Respiratory modulation of MSNA was quantified during two phases of the respiratory cycle: mid-late expiration and inspiration/postinspiration. All groups showed respiratory modulation of MSNA (P < 0.0005). There was an interaction between the respiratory phase and group for MSNA [bursts/100 heartbeats (HB) (P = 0.004) and bursts/min (P = 0.029)], with smaller reductions in MSNA during inspiration observed in PMF versus the other groups. Respiratory modulation of blood pressure was also reduced in PMF versus YF (6 [2] vs. 12 [9] mmHg, P = 0.008) and YM (13 [13] mmHg, P = 0.001, median [interquartile range]). The magnitude of respiratory sympathetic modulation was related to resting blood pressure in PMF only, such that individuals with less modulation had greater resting blood pressure. The data indicate that aging in postmenopausal females is associated with less inspiratory inhibition of MSNA. This correlated with a higher resting blood pressure in PMF only. Thus, the reduced modulation of MSNA could contribute to the age-related rise in blood pressure that occurs in females.NEW & NOTEWORTHY The current study demonstrates that respiratory modulation of sympathetic nerve activity (SNA) is reduced in healthy postmenopausal (PMF) versus premenopausal females (YF). Furthermore, respiratory sympathetic modulation was negatively related to resting blood pressure in postmenopausal females, such that blood pressure was greater in individual with less modulation. Reduced respiratory sympathetic modulation may have implications for the autonomic control of blood pressure in aging postmenopausal females, by contributing to age-related sympathetic activation and reducing acute, respiratory-linked blood pressure variation.

Melatonin supplementation reduces nighttime blood pressure but does not affect blood pressure reactivity in normotensive adults on a high-sodium diet

High-sodium diets (HSDs) can cause exaggerated increases in blood pressure (BP) during physiological perturbations that cause sympathetic activation, which is related to cardiovascular risk. Melatonin supplementation has been shown to play a role in BP regulation. Our aim was to examine the effects of melatonin taken during an HSD on 24-h BP and BP reactivity during isometric handgrip (IHG) exercise, postexercise ischemia (PEI), and the cold pressor test (CPT). Twenty-two participants (11 men/11 women, 26.5 ± 3.1 yr, BMI: 24.1 ± 1.8 kg/m2, BP: 111 ± 9/67 ± 7 mmHg) were randomized to a 10-day HSD (6,900 mg sodium/day) that was supplemented with either 10 mg/day of melatonin (HSD + MEL) or placebo (HSD + PL). Twenty-four-hour ambulatory BP monitoring was assessed starting on day 9. Mean arterial pressure (MAP) was quantified during the last 30 s of IHG at 40% of maximal voluntary contraction and CPT, and during 3 min of PEI. Melatonin did not change 24-h MAP (HSD + PL: 83 ± 6 mmHg; HSD + MEL: 82 ± 5 mmHg; P = 0.23) but decreased nighttime peripheral (HSD + PL: 105 ± 10 mmHg; HSD + MEL: 100 ± 10 mmHg; P = 0.01) and central systolic BP (HSD + PL: 97 ± 9 mmHg; HSD + MEL: 93 ± 8 mmHg; P = 0.04) on the HSD compared with the HSD + PL. The absolute and percent change in MAP during IHG was not different between conditions (all P > 0.05). In conclusion, melatonin supplementation did not alter BP reactivity to the perturbations tested on an HSD but may be beneficial in lowering BP in young healthy normotensive adults.NEW & NOTEWORTHY BP reactivity was assessed during isometric handgrip (IHG) exercise, postexercise ischemia (PEI), and the cold pressor test (CPT) after 10 days of a high-sodium diet with and without melatonin supplementation. Melatonin did not alter BP reactivity in healthy normotensive men and women. However, melatonin did decrease nighttime peripheral and central systolic BP, suggesting it may be beneficial in lowering BP even in those with a normal BP.

Outcomes of Neonates with Hypoxic-Ischemic Encephalopathy Treated with Magnesium Sulfate: A Systematic Review with Meta-analysis

OBJECTIVE

To assess magnesium sulfate (MgSO4) as a neuroprotective agent in hypoxic-ischemic encephalopathy.

STUDY DESIGN

For this systematic review, PubMed, EMBASE, the Cochrane Library, EMCARE, and MedNar were searched in November 2022 for randomized controlled trials (RCTs). Meta-analysis was conducted using Stata 16.0 and RevMan 5.3.

RESULTS

Twenty RCTs with a total sample size of 1485 were included, of which 16 were from settings where therapeutic hypothermia (TH) was not offered. Regarding MgSO4 in settings where TH was not offered, only 1 study evaluated composite outcome of death or disability at ≥18 months and reported such poor outcome in 8 of 14 control infants and 4 of 8 in the MgSO4 group. MgSO4 was not associated with mortality (RR, 0.86; 95% CI, 0.72-1.03; 13 RCTs) or hypotension (RR, 1.02; 95% CI, 0.88-1.18; 5 RCTs). Thirteen studies reported that MgSO4 improved in-hospital outcomes, such as reduced seizure burden and improved neurological status at discharge. MgSO4 reduced the risk of poor suck feeds (RR, 0.52; 95% CI, 0.40-0.68; 6RCTs) and abnormal electroencephalogram (RR, 0.64; 95% CI, 0.45-0.93; 5 RCTs). Certainty of evidence was moderate for mortality and low or very low for other outcomes. For studies with MgSO4 as an adjunct to TH, none reported on death or neurodevelopmental disability at ≥18 months. MgSO4 was not associated with mortality (RR, 0.65; 95% CI, 0.34-1.27; 3 RCTs) or hypotension (RR, 1.0; 95% CI, 0.71-1.40; 3 RCTs).

CONCLUSIONS

Evidence around long-term outcomes of MgSO4 when used with or without TH was scant. MgSO4 therapy may improve in-hospital neurological outcomes without affecting mortality in settings where TH is not offered. Well-designed RCTs for neuroprotection are needed, especially in low-resource settings.

TRIAL REGISTRATION

"Open Science Forum" (https://doi.org/10.17605/OSF.IO/FRM4D).

Adherence to aerobic training combined with high protein intake is associated with low blood pressure in Italian older adults: a cross-sectional study

BACKGROUND

Lifestyle habits have a key role in cardiometabolic health. The effects of combined aerobic training (AT) and high protein intake (HPI) on cardiometabolic parameters in older adults are not well established.

AIMS

To investigate the association of AT and HPI with blood pressure (BP), blood glucose, and total blood cholesterol levels in a sample of Italian older adults enrolled in the Longevity Check-up 7 + (Lookup 7 +) study.

METHODS

Lookup 7 + is an ongoing project started in June 2015 and conducted in unconventional settings (e.g., exhibitions, malls, health promotion campaigns) across Italy with the aim of fostering adoption of healthy lifestyles in the general population. For the present investigation, analyses were conducted in participants 65 + years and with body mass index values ≥ 18.5 kg/m2 (n = 3219). Systolic (SBP) and diastolic BP (DBP), blood glucose, and total blood cholesterol were measured. Protein intake was estimated using a 12-item food frequency questionnaire. HPI was operationalized as a daily protein intake ≥ 0.8 g/kg of body weight. AT was operationalized as the practice of running and/or swimming for 60 + minutes at least twice weekly during the previous year.

RESULTS

The mean age of the 3219 participants was 72.7 ± 5.7 years, and 55.2% were women. Adherence to AT combined with a HPI was negatively and independently associated with SPB (β: - 4.976; 95% confidence interval: - 9.8 to - 0.08). No other significant associations were observed.

DISCUSSION AND CONCLUSIONS

Our results indicate that AT combined with HPI was negatively associated with SBP in a large and relatively unselected sample of Italian older adults living in the community. These findings need confirmation by ad hoc designed studies.

Quality Review of Prone Patient Transport Protocol

OBJECTIVE

This is a retrospective quality review of LifeFlight Nova Scotia's prone patient transport protocol.

METHODS

Electronic patient care records were queried for acute respiratory distress syndrome, prone position, proning, supine to prone, and prone to prone between February 2017 and June 2022. Eligible electronic patient care records were reviewed for demographics (sex, age, and weight); method of transports (ambulance, rotor wing, or fixed wing); duration of transports; mechanical ventilation parameters; medication infusions; arterial blood gases; occurrences of mild hypoxemia (any oxygen saturation [SpO2] < 88% or decrease in SpO2 > 5%); hypotension (any episode of MAP < 65 mm Hg); severe hypoxemia (any SpO2 < 80% or decrease in SpO2 > 10%); refractory hypotension (mean arterial pressure < 65 mm Hg not responsive to vasopressor/inotropes); cardiac arrests; and displacement of central lines, arterial lines, and endotracheal tubes.

RESULTS

Seventeen prone patients were transported by ambulance, rotor wing, and fixed wing with 4 occurrences of mild hypotension, 4 occurrences of mild hypoxemia, and 1 occurrence of refractory hypotension.

CONCLUSION

Interfacility transfer of prone patients by a dedicated critical care team is feasible with minimal adverse occurrences while ensuring patients have access to the specialized lifesaving care they require.

Adrenal Emergencies

The adrenal glands drive physiologic homeostasis, with dysregulation in any direction causing multisystem dysfunction. Adrenal excess states include hyperaldosteronism which manifests with refractory hypertension and electrolyte abnormalities including hypernatremia and hypokalemia. Paragangliomas including pheochromocytoma can cause multisystem end-organ dysfunction due to catecholaminergic storm, which require rapid blood pressure control with phentolamine and identification of lesions amenable to surgical resection. Adrenal insufficiency states in contrast can result in hypotension and decompensation refractory to vasopressor administration, requiring adrenal supplementation via hydrocortisone.

Quality Improvement Curriculum for Intensive Care Unit Upgrades

Patients admitted to the hospital ward from the emergency department (ED) occasionally decompensate and require transfer to the intensive care unit (ICU). An emergency medicine (EM) curriculum focused on review of these ICU upgrade cases could improve resident knowledge related to patient acuity, critical illness, and appropriate disposition. Furthermore, initial identification of critical pathology in the ED and earlier admission to the ICU could reduce delays in care and improve patient outcomes. We performed a retrospective analysis to determine the effectiveness of a resident quality improvement curriculum evaluating cases where patients require transfer from the inpatient floor to the ICU within 12 hours of admission from the ED. We compared postgraduate year 2 (PGY-2) EM residents who participated in the ICU upgrades curriculum during their first year to PGY-2 EM residents who did not participate in the curriculum. Analysis of the 242 qualifying ICU upgrade cases from July 2019-October 2021 showed post-curriculum residents were responsible for an average of 1.0 upgrades per resident compared to an average of 1.54 upgrades per resident (P = 0.12) for pre-curriculum residents. Although there was no statistically significant difference in ICU upgrades between the groups, there was a trend toward decreased ICU upgrade cases for residents who participated in the curriculum. Common reasons for ICU upgrade included worsening respiratory distress requiring higher level of respiratory support, recurrent hypotension after initial intravenous fluid resuscitation requiring vasopressor support, and declining mental status. This retrospective study showed no significant difference in the number of ICU upgrades for residents who completed the ICU upgrades curriculum compared to residents who were not enrolled in the course. However, the study was likely underpowered to detect a significant difference in the groups, and there was a trend toward reduced ICU upgrades for residents who completed the curriculum. ICU upgrade cases were frequently associated with worsening respiratory status, hypotension, and mental status. These findings highlight the importance of reassessment of vital signs and mental status prior to determining disposition from the ED. Additional, larger studies are needed to better determine the curriculum's impact on resident proficiency in recognizing critical illness and reducing ICU upgrades.

[Managing Post Cardiac Arrest Syndrome]

Four conditions occur after cardiac arrest resuscitation and are referred to as the post-cardiac arrest syndrome. Moreover, post-cardiac arrest brain injury has the greatest impact on outcomes. Brain injury can be primary as a result of global cerebral ischemia during cardiac arrest. It may be secondary(reperfusion injury)after initiation of cardiopulmonary resuscitation. After cardiac arrest resuscitation, the patient must be managed in the intensive care unit, and it is recommended to avoid hypotension(MAP<65 mmHg), hypoxemia, and hyperoxemia. Oxygen saturation should be maintained at 94%-98%, normal ventilation(35 mmHg-45 mmHg), and body temperature below 37.5℃ for 72 h after resuscitation. The administration of anticonvulsants for abnormal electroencephalograms did not significantly affect the outcome. Prognosis should be predicted within 24 h to 72 h combining physical examination, biomarkers, electrophysiology, and imaging being predictive of poor outcomes.