Symptoms in Hypertensive Patients Presented to the Emergency Medical Service: A Comprehensive Retrospective Analysis in Clinical Settings

BACKGROUND

Hypertension is a prevalent condition with a variety of accompanying symptoms. Gender differences, specific blood pressure readings, and early signs of organ complications present intricate interplays in hypertensive individuals.

OBJECTIVE

This study aimed to investigate the relationship between hypertension and its accompanying symptoms, emphasizing gender-specific differences and potential indicators of organ complications.

METHODS

Data from 2002 participants were analyzed from a retrospective study, focusing on the presentation of symptoms, blood pressure values, and potential organ complications associated with these symptoms.

RESULTS

Of the participants, 68.8% were women with an average age of 69. Women were, on average, 8 years older than men. The average systolic blood pressure (SBP) was 188 mmHg. High-blood pressure was accompanied by symptoms in 84.9% of participants. Among those with an SBP > 180 mmHg, headaches were reported by 24.7%, and dizziness by 15.7%. Interestingly, as SBP increased, heart palpitations reports diminished with a mere 4.8% of those with SBP > 180 mmHg noting this symptom. Younger men exhibited increased chest pain and heart palpitations, while younger women more commonly reported headaches and nausea/vomiting. A significant relationship was identified between pulse pressure (PP) and symptoms, with dizziness in women and chest pain/discomfort in men being most pronounced.

CONCLUSIONS

The study underlines the importance of in-depth research on hypertensive individuals for improved symptom recognition and management. The data highlight the gender and age-specific symptom presentations and their correlation with blood pressure metrics, suggesting a need for patient-specific intervention strategies.

Non-Invasive Estimation of Central Systolic Blood Pressure by Radial Tonometry: A Simplified Approach

BACKROUND

Central systolic blood pressure (cSBP) provides valuable clinical and physiological information. A recent invasive study showed that cSBP can be reliably estimated from mean (MBP) and diastolic (DBP) blood pressure. In this non-invasive study, we compared cSBP calculated using a Direct Central Blood Pressure estimation (DCBP = MBP2/DBP) with cSBP estimated by radial tonometry.

METHODS

Consecutive patients referred for cardiovascular assessment and prevention were prospectively included. Using applanation tonometry with SphygmoCor device, cSBP was estimated using an inbuilt generalized transfer function derived from radial pressure waveform, which was calibrated to oscillometric brachial SBP and DBP. The time-averaged MBP was calculated from the radial pulse waveform. The minimum acceptable error (DCBP-cSBP) was set at ≤5 (mean) and ≤8 mmHg (SD).

RESULTS

We included 160 patients (58 years, 54%men). The cSBP was 123.1 ± 18.3 mmHg (range 86-181 mmHg). The (DCBP-cSBP) error was -1.4 ± 4.9 mmHg. There was a linear relationship between cSBP and DCBP (R2 = 0.93). Forty-seven patients (29%) had cSBP values ≥ 130 mmHg, and a DCBP value > 126 mmHg exhibited a sensitivity of 91.5% and specificity of 94.7% in discriminating this threshold (Youden index = 0.86; AUC = 0.965).

CONCLUSIONS

Using the DCBP formula, radial tonometry allows for the robust estimation of cSBP without the need for a generalized transfer function. This finding may have implications for risk stratification.

Blood Pressure Goals in Critically Ill Patients

Blood pressure goals in the intensive care unit (ICU) have been extensively investigated in large datasets and have been associated with various harm thresholds at or greater than a mean pressure of 65 mm Hg. While it is difficult to perform interventional randomized trials of blood pressure in the ICU, important evidence does not support defense of a higher pressure, except in retrospective database analyses. Perfusion pressure may be a more important target than mean pressure, even more so in the vulnerable patient population. In the cardiac ICU, blood pressure targets are tailored to specific cardiac pathophysiology and patient characteristics. Generally, the goal is to maintain adequate blood pressure within a certain range to support cardiac function and to ensure end organ perfusion. Individualized targets demand the use of both invasive and noninvasive monitoring modalities and frequent titration of medications and/or mechanical circulatory support where necessary. In this review, we aim to identify appropriate blood pressure targets in the ICU, recognizing special patient populations and outlining the risk factors and predictors of end organ failure.

OCE-205, a Selective V1a Partial Agonist, Reduces Portal Pressure in Rat Models of Portal Hypertension

Purpose

Management of decompensated cirrhosis may include the use of vasoconstrictors that can lead to serious adverse events. OCE-205 was designed as a highly selective V1a receptor partial agonist, intended to have a wider therapeutic window than full vasopressin agonists.

Methods

We aimed to characterize the activity of OCE-205 treatment in two rat models of portal hypertension (PHT). For both models, OCE-205 was administered as a subcutaneous bolus injection. Thirty male Wistar rats were fed a methionine/choline-deficient (MCD) diet to model PHT. Animals received OCE-205 (10, 25, 100, or 500 µg/kg) or intra-arterial terlipressin (100 µg/kg). In a more severe model of PHT, 11 male Sprague Dawley rats had the common bile duct surgically ligated (BDL) and received OCE-205. Portal pressure (PP) and mean arterial pressure (MAP) were measured.

Results

For PP in the MCD model, MAP increased while PP decreased in rats treated with OCE-205 or terlipressin; the peak changes to MAP were 14.7 and 33.5 mmHg, respectively. Changes in MAP began to plateau after 10 min in the OCE-205 groups, whereas in the terlipressin group, MAP rapidly increased and peaked after 20 min. Across all treatment groups in the BDL model, a dose-related decrease from baseline in PP was observed following OCE-205, plateauing as the dose increased. In all treatment groups, PP change remained negative throughout the 30-min testing period. In both PHT rat models, a reduction in PP was coupled to an increase in MAP, with both plateauing in dose-response curves.

Conclusion

Data support OCE-205 as a promising candidate for further development.

Institutional Protocol Number

Procedures were approved by the Ferring Research Institute (FRI) Institutional Animal Care and Use Committee on July 13, 2011, under protocol FRI-07-0002.

Cerebrospinal Fluid Drainage in Patients with Acute Spinal Cord Injury: A Multi-Center Randomized Controlled Trial

OBJECTIVE

The secondary phase of spinal cord injury (SCI) is characterized by ischemic injury. Spinal cord perfusion pressure (SCPP), calculated as the difference between mean arterial pressure (MAP) and intrathecal pressure (ITP), has arisen as a therapeutic target for improving outcomes. Cerebrospinal fluid drainage (CSFD) may reduce ITP and thereby increase SCPP. Randomized controlled trial to evaluate the safety and feasibility of CSFD to improve SCPP and outcomes after acute SCI.

METHODS

Inclusion criteria included acute cervical SCI within 24 hours of presentation. All patients received lumbar drain placement and appropriate decompressive surgery. Patients randomized to the control group received MAP elevation only. Patients in the experimental group received MAP elevation and CSFD to achieve ITP < 10 mmHg for 5 days. ITP and MAP were recorded hourly. Adverse events were documented and patients underwent functional assessments at enrollment, 72 hours, 90 days, and 180 days post-injury.

RESULTS

Eleven patients were enrolled; 4 were randomized to receive CSFD. CSFD patients had a mean ITP of 5.3±2.5 mmHg vs 15±3.0 mmHg in the control group. SCPP improved significantly, from 77±4.5 mmHg in the control group to 101±6.3 mmHg in the CSFD group (p<0.01). Total motor scores improved by 15±8.4 and 57±24 points in the control and CSFD groups, respectively, over 180 days. No adverse events were attributable to CSFD.

CONCLUSIONS

CSFD is a safe, effective mechanism for reducing ITP and improving SCPP in the acute period post-SCI. The favorable safety profile and preliminary efficacy should help drive recruitment in future studies.

ASPRE trial: effects of aspirin on mean arterial blood pressure and uterine artery pulsatility index trajectories in pregnancy

OBJECTIVES

The mechanism by which aspirin prevents pre-eclampsia is poorly understood, and its effects on biomarkers throughout pregnancy are unknown. We aimed to investigate the effects of aspirin on mean arterial pressure (MAP) and mean uterine artery pulsatility index (UtA-PI) using repeated measures from women at increased risk of preterm pre-eclampsia.

METHODS

This was a longitudinal secondary analysis of the Combined Multimarker Screening and Randomized Patient Treatment with Aspirin for Evidence-Based Pre-eclampsia Prevention (ASPRE) trial using repeated measures of MAP and UtA-PI. In the trial, 1620 women at increased risk of preterm pre-eclampsia were identified using the Fetal Medicine Foundation algorithm at 11 + 0 to 13 + 6 weeks, of whom 798 were randomly assigned to receive 150 mg/day aspirin and 822 were assigned to receive placebo daily from 11-14 weeks to 36 weeks of gestation or delivery, whichever came first. MAP and UtA-PI were measured at baseline and follow-up visits at 19-24, 32-34 and 36 weeks of gestation. Generalized additive mixed models with treatment by gestational age interaction terms were used to investigate the effects of aspirin on MAP and UtA-PI trajectories over time.

RESULTS

Among 798 participants in the aspirin group and 822 in the placebo group, there were 5951 MAP and 5942 UtA-PI measurements. Trajectories of raw and multiples of the median (MoM) values of MAP did not differ significantly between the two groups (MAP MoM analysis: P-value for treatment by gestational age interaction, 0.340). In contrast, trajectories of raw and MoM values of UtA-PI showed a significantly steeper decline in the aspirin group than in the placebo group, with the difference mainly driven by a more pronounced reduction before 20 weeks of gestation (UtA-PI MoM analysis: P-value for treatment by gestational age interaction, 0.006).

CONCLUSIONS

In women at increased risk of preterm pre-eclampsia, 150 mg/day aspirin initiated in the first trimester does not affect MAP but is associated with a significant decrease in mean UtA-PI, particularly before 20 weeks of gestation. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Early Fluid Balance Is Associated with 90-Day Mortality in Patients Receiving Continuous Renal Replacement Therapy

Continuous renal replacement therapy (CRRT) is widely used to control fluid balance, but the optimal fluid balance to improve the prognosis of patients remains debated. Appropriate fluid management may depend on hemodynamic status. We investigated the association between 90-day mortality and fluid balance/mean arterial pressure (MAP) in patients receiving CRRT. This single-center retrospective study was conducted between May 2018 and March 2021. Based on the cumulative fluid balance at 72 h after initiation of CRRT, the cases were divided into negative (< 0 mL) and positive (> 0 mL) fluid balance groups. Ninety-day mortality was higher in the positive fluid balance group (p=0.009). At 4 h before and after CRRT initiation, the mean MAP was lower in the positive fluid balance group (p<0.05). After multivariate cox adjustment, 72-h positive fluid balance was independently associated with 90-day mortality (p=0.004). In addition, the cumulative fluid balance was associated with 90-day mortality (p<0.05) in cases without shock, high APACHE II score, sepsis, dialysis dependence, or vasopressor use. A 72-h positive fluid balance was associated with 90-day mortality in patients receiving CRRT.

A Randomized Control Trial to Compare Hemodynamic Parameters of Patients Undergoing Percutaneous Nephrolithotomy Under Combined Spinal-Epidural and General Anesthesia in a Tertiary Hospital

Background and Aim

Percutaneous nephrolithotomy (PCNL) under epidural anesthesia has been reported to have few advantages over general anesthesia, like lower postoperative pain and less need for analgesics. There are limited studies on PCNL being performed under neuraxial anesthesia in supine position. Hence the present study was conceived to compare hemodynamic parameters in patients undergoing percutaneous nephrolithotomy (PCNL) in the supine position under combined spinal-epidural with general anesthesia (GA).

Material and Methods

A prospective, randomized control trial was conducted among 90 patients who were posted to undergo elective percutaneous nephrolithotomy in the the supine position, after obtaining Institutional Ethical Committee (IEC) approval and CTRI (Clinical Trial Registry - India) registration. Patients were randomly allotted to undergo surgery either under general anesthesia (group GA) or combined spinal epidural anesthesia (group CSE) by computer-generated random number method. Hemodynamic parameters, postoperative analgesic requirement and incidence of blood transfusion were recorded and analyzed.

Results

There was no significant difference between the two groups with respect to gender, ASA grade, surgery duration, calculus size and pulse rate. There was a statistically significant reduction in mean arterial pressure from 5 to 50 minutes of surgery and less incidence of blood transfusion in patients in the CSE group. Patients who underwent PCNL in the supine position under CSE required lesser analgesics postoperatively compared to those under general anesthesia.

Conclusion

Combined spinal epidural analgesia can be used as an alternative to general anesthesia for patients undergoing PCNL in the supine position in view of less MAP and reduced postoperative analgesic and blood transfusion requirement.

Flow down gradients: the problem of pressure in this physiology core concept

The core concepts of physiology, as first published in this journal in 2011, not only provide a noteworthy teaching approach but also encourage reflection on the fundamentals of physiology. Unfortunately, a fundamental flaw has crept into the core concept of flow down gradients. Fluids do not generally flow from high to low pressure, as claimed, but only because of a specific pressure difference, that is, the perfusion pressure. This is related to a problem that is widespread in physiology, from which even the core concepts are not free, namely, the description of mean arterial pressure (MAP) solely by means of Ohm's law of circulation, although this law actually describes perfusion pressure. Both pressures can be numerically approximately equal in the physiological case, but conceptually they remain different in principle. We solved this problem using the extended Bernoulli equation (a combination of Ohm's law and the simple Bernoulli equation). Thereafter, MAP depends on the following pressure components, all of which are essential for a basic understanding of circulation: perfusion, central venous, gravitational, and dynamic pressures. These pressures also have great pathophysiological and clinical importance, which we exemplify here. Towards the end of this paper, we provide recommendations that should be considered in teaching, whether it is a beginner or advanced course. We address physiology teachers who are open to critical constructive improvements in their teaching, especially in hemodynamics. In particular, we encourage the authors of the flow down gradients core concept to improve and refine its "unpacking."

Systolic blood pressure in acute ischemic stroke and impact on clinical outcomes

CONTEXT

Stroke is one of the largest healthcare burdens in the United States and globally. It continues to be one of the leading causes of morbidity and mortality. Patients with acute ischemic stroke (AIS) often present with elevated blood pressure (BP).

OBJECTIVES

The objective of our study was to evaluate the association of systolic blood pressure (SBP) in the emergency department (ED) with stroke severity in patients with AIS.

METHODS

This observational study was conducted at an ED with an annual census of 80,000 visits, approximately half (400) of which are for AIS. The cohort consisted of adult patients who presented to the ED within 24 h of stroke symptom onset. BP was measured at triage by a nurse blinded to the study. Stroke severity was measured utilizing the National Institutes of Health Stroke Scale (NIHSS). Statistical analyses were performed utilizing JMP 14.0. This study was approved by our medical school's institutional review board.

RESULTS

Patients with higher SBP had significantly lower NIHSS scores (p=0.0038). This association was significant even after adjusting for age and gender. By contrast, diastolic blood pressure (DBP) did not appear to impact stroke severity. There was no difference in the DBP values between men and women. Higher SBP was also significantly associated with being discharged home as well as being less likely to die in the hospital or discharged to hospice. The DBP did not demonstrate this association. Neither the SDP nor the DBP were significantly associated with the hospital length of stay (LOS). In multivariate models that included age, gender, basal metabolic index (BMI), comorbidities, and ED presentation, elevated SBP was associated with better prognosis.

CONCLUSIONS

In this cohort of patients presenting with stroke-like symptoms to the ED, higher SBP was associated with lower stroke severity and higher rates of being discharged to home rather than hospice or death.

Analgesic and hemodynamic effects of two injection approaches of dexmedetomidine in elderly cholecystolithiasis patients undergoing laparoscopic cholecystectomy: a retrospective study of 150 patients

This retrospective study investigated the effects of three dexmedetomidine (Dex) injection approaches on analgesic and hemodynamics in elderly cholecystolithiasis patients undergoing laparoscopic cholecystectomy. The clinical data of 150 elderly patients with cholecystolithiasis were collected, and they were divided into the Dex A (n=50), Dex B (n=50), and Dex C (n=50) cohorts. Patient's heart rate (HR) and mean arterial pressure (MAP) were collected at T0, T1, and T2 for blood gas analysis. The difference in oxygen content between cerebral arterial and venous blood (Da-jvO2) was calculated. The duration of surgery, occurrence of cardiovascular and respiratory suppression, and the time of spontaneous respiratory recovery and extubation were recorded. At T2, T3, and T4, HR and MAP in the Dex C group were smaller than Dex A group and Dex B group (Dex C<Dex B<Dex A, P<0.05); at T5, HR and MAP in the Dex C group were smaller than Dex A group and Dex B group (P<0.05). At T1 and T2, SjVO2 in the Dex C was smaller than the Dex A group and the Dex B group (P<0.05); Da-jvO2 in Dex C group was more remarkable than group A and group B, and group B was more incredible than Dex A at T1 and T2 (P<0.05). Dex is beneficial in reducing cerebral oxygen metabolism and maintaining hemodynamic stability in elderly patients undergoing cholecystectomy during the perioperative period. The combination of the loading and maintenance dose has a better effect.

Association between mean arterial pressure and sublingual microcirculation during major non-cardiac surgery: Post hoc analysis of a prospective cohort

OBJECTIVE

To test the hypothesis that there is an association between mean arterial pressure (MAP) and sublingual perfusion during major surgery, and perhaps an identifiable harm threshold.

METHODS

This post hoc analysis of a prospective cohort included patients who had elective major non-cardiac surgery with a duration of ≥2 h under general anesthesia. We assessed sublingual microcirculation every 30 min using SDF+ imaging and determined the De Backer score, Consensus Proportion of Perfused Vessels (Consensus PPV), and the Consensus PPV (small). Our primary outcome was the relationship between MAP and sublingual perfusion which was evaluated with linear mixed effects modeling.

RESULTS

A total of 100 patients were included, with MAP ranging between 65 mmHg and 120 mmHg during anesthesia and surgery. Over a range of intraoperative MAPs between 65 and 120 mmHg, there were no meaningful associations between blood pressure and various measures of sublingual perfusion. There were also no meaningful changes in microcirculatory flow over 4.5 h of surgery.

CONCLUSIONS

In patients having elective major non-cardiac surgery with general anesthesia, sublingual microcirculation is well maintained when MAP ranges between 65 and 120 mmHg. It remains possible that sublingual perfusion will be a useful marker of tissue perfusion when MAP is lower than 65 mmHg.

Stroke Volume and Arterial Pressure Fluid Responsiveness in Patients With Elevated Stroke Volume Variation Undergoing Major Vascular Surgery: A Prospective Intervention Study

OBJECTIVES

The identification of potential hemodynamic indicators to increase the predictive power of stroke-volume variation (SVV) for mean arterial pressure (MAP) and stroke volume (SV) fluid responsiveness.

DESIGN

A prospective intervention study.

SETTING

At a single-center university hospital.

PARTICIPANTS

Nineteen patients during major vascular surgery with 125 fluid interventions.

INTERVENTIONS

When SVV ≥13% occurred for >30 seconds, 250 mL of Ringer's lactate were given within 2 minutes.

MEASUREMENTS AND MAIN RESULTS

Hemodynamic variables, such as pulse-pressure variation (PPV) and dynamic arterial elastance (Edyn), were measured by pulse power-wave analysis. The outcomes were MAP and SV responsiveness, defined as an increase of at least 10% of MAP and SV within 5 minutes of the fluid intervention. Of the fluid interventions, 48% were MAP-responsive, and 66% were SV-responsive. The addition of PPV and Edyn cut-off values to the SVV cut-off decreased sensitivity from 1-to-0.66 to-0.82, and concomitantly increased specificity from 0-to- 0.65-to-0.93 for the prediction of MAP and SV responsiveness in the authors' study setting. The areas under the receiver operating characteristic curves of PPV and Edyn for the prediction of MAP responsiveness were 0.79 and 0.75, respectively. The areas under the receiver operating characteristic curves for PPV and Edyn to predict SV responsiveness were 0.85 and 0.77, respectively.

CONCLUSIONS

The PPV and Edyn showed good accuracy for the prediction of MAP and SV responsiveness in patients with elevated SVV during vascular surgery. Either PPV or Edyn may be used in conjunction with SVV to better predict MAP and SV fluid responsiveness in patients undergoing vascular surgery.

Association between Mean Arterial Pressure during the First 24 Hours and Clinical Outcome in Critically Ill Stroke Patients: An Analysis of the MIMIC-III Database

Abnormal blood pressure is common in critically ill stroke patients. However, the association between mean arterial pressure (MAP) and mortality of critically ill stroke patients remains unclear. We extracted eligible acute stroke patients from the MIMIC-III database. The patients were divided into three groups: a low MAP group (MAP ≤ 70 mmHg), a normal MAP group (70 mmHg < MAP ≤ 90 mmHg), and a high MAP group (MAP > 90 mmHg). The Cox proportional hazards model and restricted cubic splines were used to assess the association between MAP and mortality. Sensitivity analyses were conducted to investigate whether MAP had different effects on mortality in different subpopulations. A total of 2885 stroke patients were included in this study. The crude 7-day and 28-day mortality was significantly higher in the low MAP group than that in the normal MAP group. By contrast, patients in the high MAP group did not have higher crude 7-day and 28-day mortality than those in the normal MAP group. After multiple adjustments using the Cox regression model, patients with low MAP were consistently associated with higher 7-day and 28-day mortality than those with normal MAP in the following subgroups: age > 60 years, male, those with or without hypertension, those without diabetes, and those without CHD (p < 0.05), but patients with high MAP were not necessarily associated with higher 7-day and 28-day mortality after adjustments (most p > 0.05). Using the restricted cubic splines, an approximately L-shaped relationship was established between MAP and the 7-day and 28-day mortality in acute stroke patients. The findings were robust to multiple sensitivity analyses in stroke patients. In critically ill stroke patients, a low MAP significantly increased the 7-day and 28-day mortality, while a high MAP did not, suggesting that a low MAP is more harmful than a high MAP in critically ill stroke patients.

Evaluation of Dose Requirements Using Weight-Based versus Non-Weight-Based Dosing of Norepinephrine to Achieve a Goal Mean Arterial Pressure in Patients with Septic Shock

No consensus exists regarding optimal dosing of norepinephrine in septic shock. We aimed to evaluate if weight-based dosing (WBD) lead to higher norepinephrine doses when achieving goal mean arterial pressure (MAP) than non-weight-based dosing (non-WBD). This was a retrospective cohort study conducted after standardization of norepinephrine dosing within a cardiopulmonary ICU. Patients received non-WBD prior to standardization (November 2018-October 2019) and WBD afterwards (November 2019-October 2020). The primary outcome was the norepinephrine dose needed to attain goal MAP. Secondary outcomes included time to goal MAP, duration of norepinephrine therapy, duration of mechanical ventilation, and treatment-related adverse effects. A total of 189 patients were included (WBD 97; non-WBD 92). There was a significantly lower norepinephrine dose at goal MAP (WBD 0.05, IQR 0.02, 0.07; non-WBD 0.07, IQR 0.05, 0.14; p < 0.005) and initial norepinephrine dose (WBD 0.02, IQR 0.01, 0.05; non-WBD 0.06, 0.04, 0.12; p < 0.005) in the WBD group. No difference was observed in achievement of goal MAP (WBD 73%; non-WBD 78%; p = 0.09) or time until goal MAP (WBD 18, IQR 0, 60; non-WBD 30, IQR 14, 60; p = 0.84). WBD may lead to lower norepinephrine doses. Both strategies achieved goal MAP with no significant difference in time to goal.

Lower Versus Higher Exposure to Vasopressor Therapy in Vasodilatory Hypotension: A Systematic Review With Meta-Analysis

OBJECTIVES

Balancing the risks of hypotension and vasopressor-associated adverse effects is a daily challenge in ICUs. We conducted a systematic review with meta-analysis to examine the effect of lower versus higher exposure to vasopressor therapy on mortality among adult ICU patients with vasodilatory hypotension.

DATA SOURCES

We searched Ovid Medline, Embase, and the Cochrane Central Register of Controlled Trials for studies published from inception to October 15, 2021.

STUDY SELECTION

We included randomized controlled trials of lower versus higher exposure to vasopressor therapy in adult ICU patients with vasodilatory hypotension without language or publication status limits.

DATA EXTRACTION

The primary outcome was 90-day all-cause mortality, with seven prespecified subgroups. Secondary outcomes included shorter- and longer-term mortality, use of life-sustaining therapies, vasopressor-related complications, neurologic outcome, and quality of life at longest reported follow-up. We conducted random-effects meta-analyses to calculate summary effect measures across individual studies (risk ratio [RR] for dichotomous variables, mean difference for continuous variables, both with 95% CIs). The certainty of the evidence was assessed using Grading of Recommendations, Assessment, Development, and Evaluation. We registered this review on the International Prospective Register of Systematic Reviews (CRD42021224434).

DATA SYNTHESIS

Of 3,403 records retrieved, 68 full-text articles were reviewed and three eligible studies included. Lower exposure to vasopressors probably lowers 90-day mortality but this is based on moderate-certainty evidence, lowered for imprecision (RR, 0.94; 95% CI, 0.87-1.02). There was no credible subgroup effect. Lower vasopressor exposure may also decrease the risk of supraventricular arrhythmia (odds ratio, 0.55; 95% CI, 0.36-0.86; low certainty).

CONCLUSIONS

In patients with vasodilatory hypotension who are started on vasopressors, moderate-certainty evidence from three randomized trials showed that lower vasopressor exposure probably lowers mortality. However, additional trial data are needed to reach an optimal information size to detect a clinically important 10% relative reduction in mortality with this approach.

Evaluation of the Addition of Angiotensin II in Patients With Shock After Cardiac Surgery at a Veterans Affairs Medical Center

BACKGROUND

Vasoplegic shock occurs in up to 37% of cardiac surgery patients. We investigated the use of angiotensin II for treating vasoplegic shock in these patients.

OBJECTIVES

We assessed clinical outcomes and mortality in patients undergoing cardiac surgery at our center between March 1, 2018 and October 31, 2020 who developed vasoplegic shock, comparing those who received angiotensin II with those who did not.

METHODS

This was a retrospective chart review. Response to angiotensin II was defined as increase in or maintenance of mean arterial pressure (MAP) and decrease in background vasopressor dosage.

RESULTS

Angiotensin II was administered to 7 patients (postoperatively in 4 patients [57.1%]) with vasoplegic shock and baseline norepinephrine equivalent (NEE) of 0.49 ± 0.08 μg/kg/min; 12 patients with vasoplegic shock did not receive angiotensin II. Within 3 hours of angiotensin II administration, NEE decreased by 38.0 ± 33.1%. Angiotensin patients were more likely to newly require renal replacement therapy (66.7% vs 9.1%, P = 0.03) and had a longer, although not statistically significant, postoperative stay (23.1 vs 14.0 days, P = 0.16). Despite higher NEE requirements at baseline (0.49 vs 0.30, P = 0.03) and over the next 48 hours in the angiotensin group, no between-group differences in 7-day mortality (14.3% vs 0.0%, P = 0.37) or 30-day mortality (28.6% vs 8.3%, P = 0.52) were noted.

CONCLUSION AND RELEVANCE

In patients who developed vasoplegic shock after cardiac surgery, angiotensin II administration allowed immediate dosage reductions of other vasopressors while maintaining MAP. Despite its small sample size, this study adds to the paucity of data in these patients and highlights future research needs.

Rehabilitation assisted by Space technology-A SAHC approach in immobilized patients-A case of stroke

Introduction: The idea behind the presentation of this case relates to utilizing space technology in earth applications with mutual benefit for both patients confined to bed and astronauts. Deconditioning and the progressiveness of skeletal muscle loss in the absence of adequate gravity stimulus have been of physiological concern. A robust countermeasure to muscle disuse is still a challenge for both immobilized patients and astronauts in long duration space missions. Researchers in the space medicine field concluded that artificial gravity (AG) produced by short-radius centrifugation on a passive movement therapy device, combined with exercise, has been a robust multi-system countermeasure as it re-introduces an acceleration field and gravity load. Methods: A short-arm human centrifuge (SAHC) alone or combined with exercise was evaluated as a novel, artificial gravity device for an effective rehabilitation strategy in the case of a stroke patient with disability. The results reveal valuable information on an individualized rehabilitation strategy against physiological deconditioning. A 73-year-old woman was suddenly unable to speak, follow directions or move her left arm and leg. She could not walk, and self-care tasks required maximal assistance. Her condition was getting worse over the years, also she was receiving conventional rehabilitation treatment. Intermittent short-arm human centrifuge individualized protocols were applied for 5 months, three times a week, 60 treatments in total. Results: It resulted in significant improvement in her gait, decreased atrophy with less spasticity on the left body side, and ability to walk at least 100 m with a cane. Balance and muscle strength were improved significantly. Cardiovascular parameters improved responding to adaptations to aerobic exercise. Electroencephalography (EEG) showed brain reorganization/plasticity evidenced through functional connectivity alterations and activation in the cortical regions, especially of the precentral and postcentral gyrus. Stroke immobility-related disability was also improved. Discussion: These alterations were attributed to the short-arm human centrifuge intervention. This case study provides novel evidence supporting the use of the short-arm human centrifuge as a promising therapeutic strategy in patients with restricted mobility, with application to astronauts with long-term muscle disuse in space.

Relationship Between Mean Arterial Pressure and Furosemide Stress Test Success Rates: A Retrospective Cohort Study

BACKGROUND

The furosemide stress test (FST) is a safe and easy assessment of renal tubular function. Other factors, such as mean arterial pressure (MAP), which may influence the success rates of the FST, have not been well defined.

OBJECTIVE

To evaluate the relationship between MAP and success rates of the FST in critically ill patients.

METHODS

Retrospective, single-center, institutional review board (IRB)-approved cohort study. Critically ill adult patients given at least one dose of intravenous (IV) furosemide (≥1-1.5 mg/kg) were included. Primary outcome was whether a MAP ≥ 75 mm Hg would equate to a higher FST success rate. Secondary outcome was the success rates of patient on one or more vasopressors.

RESULTS

Of 225 patients, 88 (39.1%) had a successful FST. In patients with a MAP ≥ 75 mm Hg, 60 out of 104 (57.7%) had a successful FST compared to 28 out of 121 (23.1%) of patients who had a MAP < 75 mm Hg (odds ratio [OR], 4.53, 95% CI, 2.55-8.74, P < 0.001). Patients on vasopressors at the time of the furosemide dose had lower rates of success compared to those not on vasoactive agents (30.4% versus 68.2%, p = 0.026). Limitations of this study include its retrospective design and reliance on documented urine output.

CONCLUSION AND RELEVANCE

Patients with a MAP ≥ 75 mm Hg were significantly more likely to have a successful FST compared to those with a MAP < 75 mm Hg. This represents the first report of factors that may influence FST success rates.

The difference in mean arterial pressure induced by remimazolam compared to etomidate in the presence of fentanyl at tracheal intubation: A randomized controlled trial

Background: Combined use of hypnotic and opioids during anesthesia inductions decreases blood pressure. Post-induction hypotension (PIHO) is the most common side effect of anesthesia induction. We aimed to compare the difference in mean arterial pressure (MAP) induced by remimazolam with that induced by etomidate in the presence of fentanyl at tracheal intubation. Methods: We assessed 138 adult patients with American Society of Anesthesiologists physical status I-II who underwent elective urological surgery. Patients were randomly allocated to receive either remimazolam or etomidate as alterative hypnotic in the presence of fentanyl during anesthesia induction. Comparable BIS values were achieved in both groups. The primary outcome was the difference in the MAP at tracheal intubation. The secondary outcomes included the characteristics of anesthesia, surgery, and adverse effects. Results: The MAP was higher in the etomidate group than in the remimazolam group at tracheal intubation (108 [22] mmHg vs. 83 [16] mmHg; mean difference, -26; 95% confidence interval [CI], -33 to -19; p < 0.0001). Heart rate was significantly higher in the etomidate group than in the remimazolam group at tracheal intubation. The patients' condition warranted the administration of ephedrine more frequently in the remimazolam group (22%) than in the etomidate group (5%) (p = 0.0042) during anesthesia induction. The remimazolam group had a lower incidence of hypertension (0% vs. 9%, p = 0.0133), myoclonus (0% vs. 47%, p < 0.001), and tachycardia (16% vs. 35%, p = 0.0148), and a higher incidence of PIHO (42% vs. 5%, p = 0.001) than the etomidate group during anesthesia induction. Conclusion: Remimazolam was associated with lower MAP and lower heart rate compared to etomidate in the presence of fentanyl at tracheal intubation. Patients in the remimazolam group had a higher incidence of PIHO, and their condition warranted the administration of ephedrine more frequently than in the etomidate group during anesthesia induction.

Arterial site selection for measurement of mean arterial pressure in septic shock patients on high-dose norepinephrine

Background

The guidelines of the Surviving Sepsis Campaign suggest using invasive blood pressure (IBP) measurement in septic shock patients, without specifying for a preferred arterial site for accuracy in relation to the severity of septic shock. The objective of this study was to determine the mean arterial pressure (MAP) gradient between the femoral and radial artery sites in septic shock patients.

Method

This prospective study was carried out at a 20-bed ICU in a university hospital. Simultaneous MAP measurements at femoral and radial arterial sites were obtained in septic shock patients receiving norepinephrine (≥0.1 μg/kg/min), with a pre-planned subgroup analysis for those receiving a high dose of norepinephrine (≥0.3 μg/kg/min).

Results

The median norepinephrine dose across all 80 patients studied, including 59 patients on a high dose, was 0.4 (0.28-0.7) μg/kg/min. Overall, simultaneous measurement of MAP (mmHg) at the femoral and radial arterial sites produced mean (95% CI) MAP values of 81 (79-83) and 78 (76-80), respectively, with a mean difference of 3.3 (2.67-3.93), p < 0.001. In Bland-Altman analysis of MAP measurements, the detected effect sizes were 1.14 and 1.04 for the overall and high-dose cohorts, respectively, which indicates a significant difference between the measurements taken at each of the two arterial sites. The Pearson correlation coefficient indicated a weak but statistically significant correlation between MAP gradient and norepinephrine dose among patients receiving a high dose of norepinephrine (r = 0.289; p = 0.026; 95% CI 0.036-0.508).

Conclusion

In septic shock patients, MAP readings were higher at the femoral site than at the radial site, particularly in those receiving a high dose of norepinephrine.

Clinical trial registration

[ClinicalTrials.gov], identifier [NCT03475667].

Optimized Arterial Line Artifact Identification Algorithm Cleans High-Frequency Arterial Line Data With High Accuracy in Critically Ill Patients

High-frequency data streams of vital signs may be used to generate individualized hemodynamic targets for critically ill patients. Central to this precision medicine approach to resuscitation is our ability to screen these data streams for errors and artifacts. However, there is no consensus on the best method for data cleaning. Our goal was to determine whether an error-checking algorithm developed for intraoperative use could be applied to high volumes of arterial line data in an ICU population.

DESIGN

Multicenter observational study.

SETTING

ICUs across Ontario, Canada.

PATIENTS

Nested cohort of ICU patients with shock and/or respiratory failure requiring invasive mechanical ventilation.

INTERVENTIONS

High-frequency blood pressure data was analyzed. Systolic, diastolic, and mean arterial pressure minute averages were calculated. For manual analysis, a trained researcher retrospectively reviewed mean arterial pressure data, removing values that were deemed nonphysiological. The algorithm was implemented and identified artifactual data.

MEASUREMENTS AND MAIN RESULTS

Arterial line data was extracted from 15 patients. A trained researcher manually reviewed 40,798 minute-by-minute data points, then subsequently analyzed them with the algorithm. Manual review resulted in the identification of 119 artifacts (0.29%). The optimized algorithm identified 116 (97%) of these artifacts. Five hundred thirty-seven data points were erroneously removed or modified. Compared with manual review, the modified algorithm incorporating absolute thresholds of greater than 30 and less than 200 mm Hg had 97.5% sensitivity, 98.7% specificity, and a Matthew correlation coefficient of 0.41.

CONCLUSIONS

The error-checking algorithm had high sensitivity and specificity in detecting arterial line blood pressure artifacts compared with manual data cleaning. Given the growing use of large datasets and machine learning in critical care research, methods to validate the quality of high-frequency data is important to optimize algorithm performance and prevent spurious associations based on artifactual data.

The blood pressure targets in sepsis patients with acute kidney injury: An observational cohort study of multiple ICUs

Background

The maintenance of blood pressure is pivotal in preventing sepsis with acute kidney injury (AKI). Especially in sepsis patients treated with vasopressors. The optimal the blood pressure has been controversial to maintain renal perfusion. This study aims to explore the blood pressure target in sepsis with AKI.

Methods

We retrieved patient data from the MIMIC IV and eICU databases. The Lasso regression model was used to identify the relationship between blood pressure and sepsis in patients with AKI and remove collinearity among variables. Generalized additive models were used to estimate the blood pressure range in patients with sepsis with AKI. Statistical methods such as multivariable logistic regression, propensity score analysis, inversion probability-weighting, and doubly robust model estimation were used to verify the target blood pressure for patients with sepsis and AKI.

Results

In total, 17874 patients with sepsis were included in this study. the incidence of AKI may be related to the level of mean article pressure (MAP) and diastolic blood pressure (DBP) in sepsis patients. The range of MAPs and DBPs may be 65-73 mmHg and 50-60 mmHg in AKI patients without hypertension. The range of MAPs and DBPs may be 70-80 mmHg and 54-62 mmHg in AKI patients with hypertension. The prognosis of sepsis with AKI was unaffected by MAP or DBP. Systolic blood pressure is not associated with sepsis in patients with AKI.

Conclusions

To ensure renal perfusion, AKI patients with hypertension may require a higher MAP [70-80] versus (65-73), mmHg] and DBP [(54-62) vs (50-60), mmHg] than patients without hypertension.

Point/counterpoint: We should take the direction of blood pressure change into consideration for dynamic cerebral autoregulation quantification

Accumulating evidence suggests asymmetrical responses of cerebral blood flow during large transient changes in mean arterial pressure. Specifically, the augmentation in cerebral blood flow is attenuated when mean arterial pressure acutely increases, compared with declines in cerebral blood flow when mean arterial pressure acutely decreases. However, common analytical tools to quantify dynamic cerebral autoregulation assume autoregulatory responses to be symmetric, which does not seem to be the case. Herein, we provide the rationale supporting the notion we need to consider the directional sensitivity of large and transient mean arterial pressure changes when characterizing dynamic cerebral autoregulation.