Haemodynamic assessment and management of hypotension in the preterm.

The management of low blood flow states in premature neonates is fraught with many challenges. We remain over-reliant on regimented stepwise protocols that use mean blood pressure as a threshold for intervention to guide treatment, without giving due consideration to the underlying pathophysiology. The current available evidence does not reflect the need to concentrate on the unique pathophysiology of the preterm infant and thus leads to widespread misuse of vasoactive agents that often do not provide the desired clinical effect. Therefore, understanding the underlying pathophysiological underpinnings of haemodynamic compromise may better guide choice of agent and assess physiological response to the selected intervention.

Impact of Using Blood Warmer During Continuous Kidney Replacement Therapy in Patients With Acute Kidney Injury.

PURPOSE: We investigated the impact of blood warmer use on hypotensive episodes in patients with acute kidney injury (AKI) receiving continuous kidney replacement therapy (CKRT). MATERIALS AND METHODS: We included patients with AKI undergoing CKRT between January 1, 2012, and January 1, 2021, at a tertiary academic hospital. Hypotensive episodes were defined as mean arterial pressure (MAP) <60 mm Hg or a decrease in MAP by ≥10 mm Hg, systolic blood pressure (SBP) < 90 mm Hg or a decrease in SBP by ≥20 mm Hg, or increased vasopressor requirement. These were analyzed by Poisson regression with repeated-measures analysis of variance using generalized estimation equation. RESULTS: There were 669 patients with AKI that required CKRT. Use of blood warmer on first day of CKRT was in 324 (48%) patients. Incidence rate ratio of hypotensive episodes during the first 24-h of CKRT in patients where a blood warmer was used was 1.06 (95% confidence interval [CI]: 0.98-1.13) compared to those where blood warmer was not used. This did not change in adjusted model. Overall, the within-subject effect of temperature on hypotensive episodes showed that higher temperature was associated with fewer episodes (0.94, 95% CI: 0.9-0.99 per 10 degrees increase, P = .007). CONCLUSION: Blood rewarming was not associated with hypotensive episodes during CKRT.

Evaluation and management of hypotensive patients in the emergency department.

Hypotension can be a sign of significant underlying pathology, and if it is not rapidly identified and addressed, it can contribute to organ injury. Treatment of hypotension is best targeted at the underlying etiology, although this can be difficult to discern early in a patient's disease course. Expedited bedside evaluation with rapid initiation of treatment based on the most likely underlying etiology is paramount, followed by serial reassessment of the patient's condition. This review synthesizes the key aspects of the presentation and evaluation of a patient with hypotension, including salient historical features, physical examination findings, and diagnostic tests that can help guide treatment.

Paralysis under pressure.

Treating cardiovascular paralysis with epidural electrical neuromodulation.

Non-pharmacological interventions for older adults with postprandial hypotension: A scoping review.

BACKGROUND: Older adults frequently suffer from postprandial hypotension, associated with an increased risk of falls, syncope, acute cardiovascular and cerebrovascular diseases, and even death. Researchers use non-pharmacological interventions, but related literature is dispersed and lacks a latest summary. OBJECTIVE: The aim of this study was to map and examine non-pharmacological interventions currently employed to assist older adults with postprandial hypotension and lay a solid foundation for future studies. METHODS: This study adhered to the JBI methodology for scoping reviews and preferred reporting items for systematic reviews and meta-analyses extension for scoping reviews. PubMed, Web of Science, Embase, Cochrane Library, CINAHL, SCOPUS, Chinese Biomedical Journal, China National Knowledge Infrastructure, VIP and WAN FANG Data were retrieved from their inception to 1 August 2022. RESULTS: Two randomized controlled trials and seven quasi-experimental studies were included. Small meals, exercise interventions, fibre with meals, green tea and water therapy have been reported to prevent postprandial hypotension effectively; however, position changes have been reported to have no impact on postprandial blood pressure decrease. Additionally, the blood pressure determination methods and test meals may affect observed trial effects. CONCLUSION: Large samples and long-term follow-up studies are needed to prove the efficacy and safety of existing non-pharmacological interventions. Future studies should develop a BP determination method based on the postprandial BP decline trajectory induced by a given test meal to improve the reliability of study results. RELEVANCE TO CLINICAL PRACTICE: This review broadly summarizes existing studies on developing and validating non-pharmacological interventions for older adults with postprandial hypotension. It also analyses special factors that may influence the trial effects. This may provide a useful reference for future research.

Automated partial resuscitative endovascular balloon occlusion of the aorta reduces blood loss and hypotension in a highly lethal porcine liver injury model.

BACKGROUND: Partial and intermittent resuscitative endovascular balloon occlusion of the aorta (pREBOA and iREBOA, respectively) are lifesaving techniques designed to extend therapeutic duration, mitigate ischemia, and bridge patients to definitive hemorrhage control. We hypothesized that automated pREBOA balloon titration compared with automated iREBOA would reduce blood loss and hypotensive episodes over a 90-minute intervention phase compared with iREBOA in an uncontrolled liver hemorrhage swine model. METHODS: Twenty-four pigs underwent an uncontrolled hemorrhage by liver transection and were randomized to automated pREBOA (n = 8), iREBOA (n = 8), or control (n = 8). Once hemorrhagic shock criteria were met, controls had the REBOA catheter removed and received transfusions only for hypotension. The REBOA groups received 90 minutes of either iREBOA or pREBOA therapy. Surgical hemostasis was obtained, hemorrhage volume was quantified, and animals were transfused to euvolemia and then underwent 1.5 hours of automated critical care. RESULTS: The control group had significantly higher mortality rate (5 of 8) compared with no deaths in both REBOA groups, demonstrating that the liver injury is highly lethal ( p = 0.03). During the intervention phase, animals in the iREBOA group spent a greater proportion of time in hypotension than the pREBOA group (20.7% [16.2-24.8%] vs. 0.76% [0.43-1.14%]; p < 0.001). The iREBOA group required significantly more transfusions than pREBOA (21.0 [20.0-24.9] mL/kg vs. 12.1 [9.5-13.9] mL/kg; p = 0.01). At surgical hemostasis, iREBOA had significantly higher hemorrhage volumes compared with pREBOA (39.2 [29.7-44.95] mL/kg vs. 24.7 [21.6-30.8] mL/kg; p = 0.04). CONCLUSION: Partial REBOA animals spent significantly less time at hypotension and had decreased transfusions and blood loss. Both pREBOA and iREBOA prevented immediate death compared with controls. Further refinement of automated pREBOA is necessary, and controller algorithms may serve as vital control inputs for automated transfusion. LEVEL OF EVIDENCE: Therapeutic/Care Management; Level III.

The Optimization of Outpatient Hemodialysis Management for Acute Kidney Injury Requiring Dialysis Patients: A Quality Improvement Study.

INTRODUCTION: In 2017, the Centers for Medicare and Medicaid Services allowed survivors of hospitalized acute kidney injury requiring dialysis (AKI-D) who were ambulatory and still dependent on hemodialysis (HD) to receive treatment in outpatient dialysis facilities. This policy change generated the ongoing need to improve AKI-D care in the outpatient setting. METHODS: Quality improvement study in adult patients admitted to an outpatient HD unit with the diagnosis of AKI-D. We developed a protocol to manage these patients that included: (a) multidisciplinary evaluations; (b) personalized 3-tier HD prescription for dose/ultrafiltration rate and frequency; (c) weekly assessment of kidney recovery; and (d) patient empowerment. Patient- and protocol-specific characteristics were described. We analyzed hourly HD data and protocol adherence, and relevant hemodynamic data were compared according to HD-free survival at 90 days. RESULTS: A total of 457.3 h of HD from 9 patients under the AKI-D protocol were interrogated. Three out of 9 patients were alive and liberated from HD within the first 90 days of outpatient HD. Overall protocol adherence was 53.8% and did not differ by HD-free survival (54.5% vs. 53.7% in those that recovered vs. not). Protocol adherence was associated with fewer intradialytic hypotension events (peak to nadir blood pressure, p < 0.01), while intradialytic hypotension (pre- to post-blood pressure) occurred more frequently in patients who did not recover kidney function (p = 0.009). CONCLUSION: We demonstrated the feasibility of implementing a management protocol for AKI-D patients in an outpatient dialysis facility. We found that fewer episodes of intradialytic hypotension occurred when the outpatient HD management was adherent to the protocol. The feasibility of this protocol should be confirmed in other facilities, and importantly, efficacy testing to evaluate its impact on AKI-D outpatient care is necessary.

Early Restrictive or Liberal Fluid Management for Sepsis-Induced Hypotension.

BACKGROUND: Intravenous fluids and vasopressor agents are commonly used in early resuscitation of patients with sepsis, but comparative data for prioritizing their delivery are limited. METHODS: In an unblinded superiority trial conducted at 60 U.S. centers, we randomly assigned patients to either a restrictive fluid strategy (prioritizing vasopressors and lower intravenous fluid volumes) or a liberal fluid strategy (prioritizing higher volumes of intravenous fluids before vasopressor use) for a 24-hour period. Randomization occurred within 4 hours after a patient met the criteria for sepsis-induced hypotension refractory to initial treatment with 1 to 3 liters of intravenous fluid. We hypothesized that all-cause mortality before discharge home by day 90 (primary outcome) would be lower with a restrictive fluid strategy than with a liberal fluid strategy. Safety was also assessed. RESULTS: A total of 1563 patients were enrolled, with 782 assigned to the restrictive fluid group and 781 to the liberal fluid group. Resuscitation therapies that were administered during the 24-hour protocol period differed between the two groups; less intravenous fluid was administered in the restrictive fluid group than in the liberal fluid group (difference of medians, -2134 ml; 95% confidence interval [CI], -2318 to -1949), whereas the restrictive fluid group had earlier, more prevalent, and longer duration of vasopressor use. Death from any cause before discharge home by day 90 occurred in 109 patients (14.0%) in the restrictive fluid group and in 116 patients (14.9%) in the liberal fluid group (estimated difference, -0.9 percentage points; 95% CI, -4.4 to 2.6; P = 0.61); 5 patients in the restrictive fluid group and 4 patients in the liberal fluid group had their data censored (lost to follow-up). The number of reported serious adverse events was similar in the two groups. CONCLUSIONS: Among patients with sepsis-induced hypotension, the restrictive fluid strategy that was used in this trial did not result in significantly lower (or higher) mortality before discharge home by day 90 than the liberal fluid strategy. (Funded by the National Heart, Lung, and Blood Institute; CLOVERS ClinicalTrials.gov number, NCT03434028.).

Central Venous Waveform Analysis and Cardiac Output in a Porcine Model of Endotoxemic Hypotension and Resuscitation.

BACKGROUND: Cardiac output (CO) is a valuable proxy for perfusion, and governs volume responsiveness during resuscitation from distributive shock. The underappreciated venous system has nuanced physiology that confers valuable hemodynamic information. In this investigation, deconvolution of the central venous waveform by the fast Fourier transformation (FFT) algorithm is performed to assess its ability to constitute a CO surrogate in a porcine model of endotoxemia-induced distributive hypotension and resuscitation. STUDY DESIGN: Ten pigs were anesthetized, catheterized, and intubated. A lipopolysaccharides infusion protocol was used to precipitate low systemic vascular resistance hypotension. Four crystalloid boluses (10 cc/kg) were then given in succession, after which heart rate, mean arterial pressure, thermodilution-derived CO, central venous pressure (CVP), and the central venous waveform were collected, the last undergoing fast Fourier transformation analysis. The amplitude of the fundamental frequency of the central venous waveform's cardiac wave (f0-CVP) was obtained. Heart rate, mean arterial pressure, CVP, f0-CVP, and CO were plotted over the course of the boluses to determine whether f0-CVP tracked with CO better than the vital signs, or than CVP itself. RESULTS: Distributive hypotension to a 25% mean arterial pressure decrement was achieved, with decreased systemic vascular resistance (mean 918 ± 227 [SD] dyne/s/cm-5 vs 685 ± 180 dyne/s/cm-5; p = 0.038). Full hemodynamic parameters characterizing this model were reported. Slopes of linear regression lines of heart rate, mean arterial pressure, CVP, f0-CVP, and CO were -2.8, 1.7, 1.8, 0.40, and 0.35, respectively, demonstrating that f0-CVP values closely track with CO over the 4-bolus range. CONCLUSIONS: Fast Fourier transformation analysis of the central venous waveform may allow real-time assessment of CO during resuscitation from distributive hypotension, possibly offering a venous-based approach to clinical estimation of volume responsiveness.

Mesenteric traction syndrome - Incidence, impact, and treatment: A systematic scoping review of the literature.

BACKGROUND: Mesenteric traction syndrome (MTS) is commonly seen during major abdominal surgery and is characterised by facial flushing, hypotension, and tachycardia 15 min into surgery. MTS also impacts the postoperative course, as severe MTS has been associated with increased postoperative morbidity. However, despite MTS being common and severe MTS causing increased postoperative morbidity, the gaps in the literature are not clearly defined. We aimed to examine the diagnostic criteria, incidence, intraoperative and postoperative impact, and potential preventative measures of MTS while highlighting potential gaps in the literature. METHODS: We followed the Prisma guidelines and performed a systematic literature search. We included only human studies examining MTS. All hits were screened for title and abstract, followed by a full-text review by at least two authors for determining eligibility for inclusion. Data were extracted and risk of bias was assessed by two independent reviewers. RESULTS: A total of 37 studies, comprising 1102 patients were included in the review. The combined incidence of MTS during open abdominal surgery was found to be 76%, with 35% developing severe MTS. It was found that the development of MTS was associated with marked haemodynamic changes. It was also found that several different subjective diagnostic criteria exist and that severe MTS was associated with increased postoperative morbidity. Furthermore, several preventative measures for protecting against MTS have been examined, but only on the incidence of MTS and not on the postoperative course. CONCLUSION: MTS occurs in 76% of patients undergoing major abdominal surgery and is associated with deleterious haemodynamic effects, which are more pronounced in patients developing severe MTS. Severe MTS is also associated with a worse postoperative outcome. However, gaps are still present in the current literature on MTS.

Preperitoneal Pelvic Packing for Hypotension Has a Greater Risk of Venous Thromboembolism Than Angioembolization: Management of Refractory Hypotension in Closed Pelvic Ring Injury.

BACKGROUND: Patients with traumatic pelvic ring injury may present with hypotension secondary to hemorrhage. Preperitoneal pelvic packing (PPP) and angioembolization (AE) are alternative interventions for management of hypotension associated with pelvic ring injury refractory to resuscitation and circumferential compression. We hypothesized that PPP may be independently associated with increased risk of venous thromboembolism (VTE) compared with AE in patients with hypotension and pelvic ring injury. METHODS: Adult patients with pelvic ring injury and hypotension managed with PPP or AE were retrospectively identified in the Trauma Quality Improvement Program (TQIP) database from 2015 to 2019. Patients were matched on a propensity score for receiving PPP based on patient, injury, and treatment factors. The primary outcome was the risk of VTE after matching on the propensity score for treatment. The secondary outcomes included inpatient clinically important deep vein thrombosis, pulmonary embolism, respiratory failure, mortality, unplanned reoperation, sepsis, surgical site infection, hospital length of stay, and intensive care unit (ICU) length of stay. RESULTS: In this study, 502 patients treated with PPP and 2,439 patients treated with AE met inclusion criteria. After propensity score matching on age, smoking status, Injury Severity Score, Tile B or C pelvic ring injury, bilateral femoral fracture, serious head injury, units of plasma and platelets given within 4 hours of admission, laparotomy, and level-I trauma center facility designation, 183 patients treated with PPP and 183 patients treated with AE remained. PPP, compared with AE, was associated with a 9.8% greater absolute risk of VTE, 6.5% greater risk of clinically important deep vein thrombosis, and 4.9% greater risk of respiratory failure after propensity score matching. CONCLUSIONS: PPP for the management of hypotension associated with pelvic ring injury is associated with higher rates of inpatient VTE events and sequelae compared with AE. LEVEL OF EVIDENCE: Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.