Target Mean Arterial Pressure Research Articles

Perfusion index and mean arterial pressure after return of spontaneous circulation in out-of hospital cardiac arrest (OHCA) and their relationship with perfusion and survival

Abstract Funding Acknowledgements None. Background Current guidelines for post-cardiac arrest care recommend targeting mean arterial pressure (MAP) to restore adequate perfusion indicated by adequate urine output (UO) and normal or decreasing lactate, avoiding hypotension (MAP < 65 mmHg). The peripheral perfusion index (PI) is the ratio of the pulsatile blood flow to the non-pulsatile blood flow measured peripherally by a standard pulse-oximeter, and it represents a promising non-invasive tool to assess perfusion. The goal of this study is to assess whether prehospital PI and MAP measurements are associated with lactate clearance (LC), adequate UO and 30-days survival with good neurological outcome. Methods A retrospective analysis of prospectively collected data (January 2018 - March 2023) in two cardiac arrest registries located in Italy and Belgium was performed. PI was automatically and continuously measured by the manual monitor/defibrillator. The mean PI value of each minute after ROSC was extracted from the monitor data report and the mean value of 30 min of PI monitoring (MPI30) was calculated and categorized in tertiles (MPI30 T1-T3). The lowest prehospital value for MAP recording was considered. LC was defined by a serum lactate level <2 mmol/L at 6 hours. Inadequate UO was defined as < 0.5mL/kg/h averaged at 12 hours. Neurological outcome was assessed with the Cerebral Performance Category (CPC) at 30 days. Results Out of the 397 OHCA patients admitted to the ICU after ROSC enrolled over the study period 206 had a MPI30 value available and were included in this study; MAP value was available in 186 patients. In the subgroup of patients with hypotension, patients with MPI30 in T1 showed higher incidence of inadequate UO at 12 hours (78.9% vs 25.8%, p<0.001). At multivariable logistic regression, after adjusting for MAP, shockable rhythm, age, and dosage of adrenaline administered, MPI30 was independently associated with inadequate UO (OR 0.68, 95% CI 0.50-0.91, p=0.01). Patients with hypotension and MPI30 in T1 showed lower LC at 6h (15.8% vs 43.4%, p=0.02) when compared to the remaining population. At multivariable Cox proportional-hazard regression, after correction for shockable rhythm, age, and total amount of adrenaline administered, patients with hypotension and MPI30 in T1 showed lower survival with CPC 1-2 at 30 days (HR 2.61, 95% CI 1.52-4.51, p=<0.001) when compared to patients without hypotension or with hypotension but MPI30 in T2-T3. No difference in LC, adequate UO and survival with good neurological outcome was found between patients with hypotension and MPI30 in T2-T3 compared to patients without hypotension. Conclusion PI is a useful indicator of perfusion in patients with hypotension after OHCA. Patients with hypotension and reduced PI showed higher incidence of inadequate UO and lower incidence of LC, as well as association with lower survival at 30 days with CPC 1-2.Lactate clearenceSurvival at 30days with CPC 1-2

Impact of arginine-vasopressin on regional perfusions in a porcine model of post-resuscitation syndrome

BackgroundPost-cardiac arrest (CA) shock is associated with multiple organ failure, including acute kidney injury, and is the leading cause of early death among patient successfully resuscitated from CA. Arginine-vasopressin (AVP) may be an interesting therapeutic alternative or complement to noradrenaline (NAD) to both control shock and preserve regional, especially renal, organ perfusions. Methods18 swine (24–39 kg) were submitted to 14 min of ventricular fibrillation and cardio-pulmonary resuscitation. After return of spontaneous circulation (ROSC), animals randomly received either AVP, NAD or AVP-NAD combination for maintaining a targeted mean arterial pressure of 70 ± 5 mmHg for 6 h. Haemodynamic and biological parameters, including kidney function biomarkers and diuresis, were monitored throughout the follow-up. ResultsTargeted mean arterial pressure was successfully obtained in the NAD (n = 6) and the AVP-NAD (n = 6) groups, but not in the AVP group (n = 6), where 4 animals died. As compared to NAD alone, renal blood flow (2.9 ± 1.15 vs 4.36 ± 0.64 mL//kg/min in NAD and AVP-NAD groups) and diuresis were higher in the AVP-NAD group. This was associated with a reduction of carotid blood flow and a more severe metabolic acidosis during the first 3 h of follow-up in the AVP-NAD group as compared to NAD group. ConclusionCombination of AVP and NAD improved renal perfusion and diuresis but reduced carotid blood flow as compared to NAD alone in a porcine model of post-resuscitation syndrome. AVP alone failed to manage shock and led to mortality.

A Systematic Review and Meta-Analysis of the Timing of Vasopressor Therapy in Patients with Septic Shock: Assessing Clinical Outcomes and Implication

Background Septic shock, is associated with a high mortality rate and increased expenses. Currently, the first-line therapy for septic shock entails administering resuscitation fluids followed by infusing vasopressors when the blood pressure goal is not achieved. The recommended first-line vasopressor is norepinephrine, followed by vasopressin, epinephrine, angiotensin II, and dopamine. There is still a controversy on when each vasopressor should be administered. Therefore, we conducted this review to determine the impact and implications of vasopressor timing in septic shock patients. Methods PubMed, Medline, Cochrane Library, Web of Science, and Google Scholar databases were comprehensively searched for potential studies until October 2023. The methodological quality and bias assessment of valid records was examined with the Newcastle Ottawa Scale and Cochrane’s risk of bias tool. Additionally, all the meta-analyses were performed with Review Manager software. Results Twelve articles were eligible for review and analysis. Pooled analyses of data from 7 of these studies demonstrated lower incidence of mortality and shorter duration to achieve target mean arterial pressure in the early vs. late epinephrine groups (OR:0.44; 95%CI: 0.35–0.55; p<0.00001 and MD:-1.17; 95%CI:-2.00– -0.34; p=0.0006). However, the length of ICU stay didn’t differ between the early and late norepinephrine group (MD:0.55; 95%CI: -0.52–1.62; p=0.31). The subgroup analyses show that early vasopressin is associated with a decreased mortality than late administration (OR:0.60; 95%CI:0.41–0.90; p=0.01). Similarly, the pooled analysis has shown that early concomitant administration of vasopressin and norepinephrine is associated with a shorter duration to achieve target MAP than norepinephrine alone (MD:-3.15; 95%CI:-4.40– -1.90;p<0.00001). Conclusion Early administration of norepinephrine has a mortality benefit and improves the duration taken to attain and sustain the goal MAP. Furthermore, early vasopressin possesses the potential to lower the fatality rate in individuals experiencing septic shock. However, further research is required to validate this finding.

Capillary refill time response to a fluid challenge or a vasopressor test: an observational, proof-of-concept study

BackgroundSeveral studies have validated capillary refill time (CRT) as a marker of tissue hypoperfusion, and recent guidelines recommend CRT monitoring during septic shock resuscitation. Therefore, it is relevant to further explore its kinetics of response to short-term hemodynamic interventions with fluids or vasopressors. A couple of previous studies explored the impact of a fluid bolus on CRT, but little is known about the impact of norepinephrine on CRT when aiming at a higher mean arterial pressure (MAP) target in septic shock. We designed this observational study to further evaluate the effect of a fluid challenge (FC) and a vasopressor test (VPT) on CRT in septic shock patients with abnormal CRT after initial resuscitation. Our purpose was to determine the effects of a FC in fluid-responsive patients, and of a VPT aimed at a higher MAP target in chronically hypertensive fluid-unresponsive patients on the direction and magnitude of CRT response.MethodsThirty-four septic shock patients were included. Fluid responsiveness was assessed at baseline, and a FC (500 ml/30 mins) was administered in 9 fluid-responsive patients. A VPT was performed in 25 patients by increasing norepinephrine dose to reach a MAP to 80–85 mmHg for 30 min. Patients shared a multimodal perfusion and hemodynamic monitoring protocol with assessments at at least two time-points (baseline, and at the end of interventions).ResultsCRT decreased significantly with both tests (from 5 [3.5–7.6] to 4 [2.4–5.1] sec, p = 0.008 after the FC; and from 4.0 [3.3–5.6] to 3 [2.6 -5] sec, p = 0.03 after the VPT. A CRT-response was observed in 7/9 patients after the FC, and in 14/25 pts after the VPT, but CRT deteriorated in 4 patients on this latter group, all of them receiving a concomitant low-dose vasopressin.ConclusionsOur findings support that fluid boluses may improve CRT or produce neutral effects in fluid-responsive septic shock patients with persistent hypoperfusion. Conversely, raising NE doses to target a higher MAP in previously hypertensive patients elicits a more heterogeneous response, improving CRT in the majority, but deteriorating skin perfusion in some patients, a fact that deserves further research.

Renin Levels and Angiotensin II Responsiveness in Vasopressor-Dependent Hypotension.

The relationship between renin levels, exposure to renin-angiotensin system (RAS) inhibitors, angiotensin II (ANGII) responsiveness, and outcome in patients with vasopressor-dependent vasodilatory hypotension is unknown. We conducted a single-center prospective observational study to explore whether recent RAS inhibitor exposure affected baseline renin levels, whether baseline renin levels predicted ANGII responsiveness, and whether renin levels at 24 hours were associated with clinical outcomes. An academic ICU in Melbourne, VIC, Australia. Forty critically ill adults who received ANGII as the primary agent for vasopressor-dependent vasodilatory hypotension who were included in the Acute Renal effects of Angiotensin II Management in Shock study. None. After multivariable adjustment, recent exposure to a RAS inhibitor was independently associated with a relative increase in baseline renin levels by 198% (95% CI, 36-552%). The peak amount of ANGII required to achieve target mean arterial pressure was independently associated with baseline renin level (increase by 46% per ten-fold increase; 95% CI, 8-98%). Higher renin levels at 24 hours after ANGII initiation were independently associated with fewer days alive and free of continuous renal replacement therapy (CRRT) (-7 d per ten-fold increase; 95% CI, -12 to -1). In patients with vasopressor-dependent vasodilatory hypotension, recent RAS inhibitor exposure was associated with higher baseline renin levels. Such higher renin levels were then associated with decreased ANGII responsiveness. Higher renin levels at 24 hours despite ANGII infusion were associated with fewer days alive and CRRT-free. These preliminary findings emphasize the importance of the RAS and the role of renin as a biomarker in patients with vasopressor-dependent vasodilatory hypotension.

The 2023 AO Spine-Praxis Guidelines in Acute Spinal Cord Injury: What Have We Learned? What Are the Critical Knowledge Gaps and Barriers to Implementation?

Narrative summary of the 2023 AO Spine-Praxis clinical practice guidelines for management in acute spinal cord injury (SCI). The objective of this article is to summarize the key findings of the clinical practice guidelines for the optimal management of traumatic and intraoperative SCI (ISCI). This article will also highlight potential knowledge translation opportunities for each recommendation and discuss important knowledge gaps and areas of future research. Systematic reviews were conducted according to accepted methodological standards to evaluate the current body of evidence and inform the guideline development process. The summarized evidence was reviewed by a multidisciplinary guidelines development group that consisted of international multidisciplinary stakeholders. The Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) approach was used to rate the certainty of the evidence for each critical outcome and the "evidence to recommendation" framework was used to formulate the final recommendations. The key recommendations regarding the timing of surgical decompression, hemodynamic management, and the prevention, diagnosis, and management of ISCI are summarized. While a strong recommendation was made for early surgery, further prospective research is required to define what constitutes sufficient surgical decompression, examine the role of ultra-early surgery, and assess the impact of early surgery in different SCI phenotypes, including central cord syndrome. Furthermore, additional investigation is required to evaluate the impact of mean arterial blood pressure targets on neurological recovery and to determine the utility of spinal cord perfusion pressure measurements. Finally, there is a need to examine the role of neuroprotective agents for the treatment of ISCI and to prospectively validate the new AO Spine-Praxis care pathway for the prevention, diagnosis, and management of ISCI. To optimize the translation of these guidelines into practice, important barriers to their implementation, particularly in underserved areas, need to be explored. Ultimately, these recommendations will help to establish more personalized approaches to care for SCI patients. The recommendations from the 2023 AO Spine-Praxis guidelines not only highlight the current best practice in the management of SCI, but reveal critical knowledge gaps and barriers to implementation that will help to guide further research efforts in SCI.

Comparison of Clonidine versus Esmolol in Controlled Hypotension in Patients Undergoing FESS Surgery

Background: FESS has its share of complications which can be a challenge for both the surgeon as well the anesthetist and achieving a bloodless surgical field is essential So the principle of controlled hypotension can be used to combat this issue.
 Methods: A hospital-based randomized comparative interventional study was conducted on 60 patients to compare Clonidine (2mcg/kg in 10 ml of saline over 10 minutes before induction followed by an infusion of 1mcg/kg/hr during maintenance) and Esmolol (1mg/kg in 10 ml of saline over 10 minutes before induction followed by an infusion of 1mg/kg/hr during maintenance) to assess and compare the hypotensive properties of both the drugs.
 Results: After the induction of anesthesia, there was a significant difference in the mean heart rate, and mean arterial pressure between the two groups throughout the intraoperative period (p-value < 0.05). Both groups achieved a target mean arterial pressure (MAP) of 65-70 mmHg and improved surgical field quality.
 Conclusion: This study concluded that clonidine and esmolol both provide hemodynamic stability and a better surgical field in functional endoscopic sinus surgery (FESS). Clonidine also helps in achieving postoperative sedation and analgesia.

Traumatic cervical spinal cord injury: Comparison of two different blood pressure targets on neurological recovery.

Controversy exists whether blood pressure augmentation therapy benefits patients suffering from spinal cord injury (SCI). This retrospective comparative study was designed to assess the impact of two different mean arterial pressure (MAP) targets (85-90 mmHg vs. 65-85 mmHg) on neurological recovery after traumatic cervical SCI. Fifty-one adult patients with traumatic cervical SCI were retrospectively divided into two groups according to their intensive care unit (ICU) MAP targets: 85-90 mmHg (higher MAP group, n = 32) and 65-85 mmHg (lower MAP group, n = 19). Invasive MAP measurements were stored as 2-min median values for 3-7 days. The severity of SCI (AIS grade and neurological level) was evaluated upon ICU stay and during rehabilitation. Neurological recovery was correlated with individual mean MAP values and with the proportion of MAP values ≥85 mmHg upon the first 3 days (3d-MAP%≥85 ). The initial AIS grades were A 29.4%, B 17.6%, C 31.4%, and D 21.6%. AIS grade improved in 24 patients (47.1%). During ICU care, 82.0% and 36.8% of the measured MAP values reached ≥85 mmHg in the higher and the lower MAP groups, respectively (p < .001). The medians of individual mean MAP values were different between the groups (90.2 mmHg vs. 81.4 mmHg, p < .001). Similarly, 3d-MAP%≥85 was higher in the higher MAP group (85.6% vs. 50.0%, p < .001). However, neurological recovery was not different between the groups, nor did it correlate with individual mean MAP values or 3d-MAP%≥85 . The currently recommended MAP target of 85-90 mmHg was not associated with improved outcomes compared to a lower target in patients with traumatic cervical SCI in this cohort.

Impact of blood pressure targets on central hemodynamics during intensive care after out-of-hospital cardiac arrest

ObjectivesThe aim was to investigate the advanced hemodynamic effects of the two MAP-targets during intensive care on systemic hemodynamics in comatose patients after cardiac arrest. DesignSecondary analysis of a randomized controlled trial. SettingPrimary vasopressor used was per protocol norepinephrine. Hemodynamic monitoring was done with pulmonary artery catheters (PAC) and measurements were made on predefined time points. The primary endpoint of this substudy was the difference in cardiac index within 48 h from a repeated measurements-mixed model. Secondary endpoints included systemic vascular resistance index (SVRI), heart rate, and stroke volume index. PatientsComatose survivors after out-of-hospital cardiac arrest. InterventionsThe “Blood pressure and oxygenations targets after out-of-hospital cardiac arrest (BOX)”-trial was a randomized, controlled, double-blinded, multicenter-study comparing targeted mean arterial pressure (MAP) of 63 mmHg (MAP63) vs 77 mmHg (MAP77). Measurements and main resultsAmong 789 randomized patients, 730 (93%) patients were included in the hemodynamic substudy. From PAC-insertion (median 1 hours after ICU-admission) and the next 48 hours, the MAP77-group received significantly higher doses of norepinephrine (mean difference 0.09 µg/kg/min, 95% confidence interval (CI) 0.07–0.11, pgroup < 0.0001). Cardiac index was significantly increased (0.20 L/min/m2 (CI 0.12–0.28), pgroup < 0.0001) as was SVRI with an overall difference of (43 dynes m2/s/cm5 (CI 7–79); pgroup = 0.02). Heart rate was increased in the MAP77-group (4 beats/minute; CI 2–6, pgroup < 0.003), but stroke volume index was not (pgroup = 0.10). ConclusionsTargeted MAP at 77 mmHg compared to 63 mmHg resulted in a higher dose of norepinephrine, increased cardiac index and SVRI. Heart rate was also increased, but stroke volume index was not affected by a higher blood pressure target.

High versus standard blood pressure target in hypertensive high-risk patients undergoing elective major abdominal surgery: a study protocol for the HISTAP randomized clinical trial

BackgroundThe intraoperative period is often characterized by hemodynamic instability, and intraoperative hypotension is a common complication. The optimal mean arterial pressure (MAP) target in hypertensive patients is still not clear. We hereby describe the protocol and detailed statistical analysis plan for the high versus standard blood pressure target in hypertensive high-risk patients undergoing elective major abdominal surgery: the HISTAP randomized clinical trial. The HISTAP trial aims at addressing whether the use of a higher intraoperative MAP target in high-risk hypertensive surgical patients scheduled for elective abdominal surgery would improve postoperative outcomes, as compared to the standard and recommended perioperative MAP, by using a composite outcome including a 30-day mortality from surgical intervention and at least one major organ dysfunction or new onset of sepsis and septic shock occurring 7 days after surgery.MethodsThe HISTAP trial is an investigator-initiated, pragmatic, parallel-grouped, randomized, stratified, analyst-blinded trial with adequate allocation sequence generation, and allocation concealment. We will allocate 636 patients to a MAP target ≥ 80 mmHg (treatment group) or to a MAP target ≥65 mmHg (control group). The primary outcome is a composite outcome including a 30-day mortality from the operation and major organ complications. Secondary outcomes are mortality at 30 days, intensive care unit (ICU) length of stay, ICU readmission, Sequential Organ Failure Assessment (SOFA) scores recorded up to postoperative day 7, overall intraoperative fluid balance, vasopressors use, and the need for reoperation. An unadjusted χ2 test will be used for the primary outcome analysis. A Cox proportional hazards model will be used to adjust the association between the primary outcome and baseline covariates.ConclusionsThe HISTAP trial results will provide important evidence to guide clinicians’ choice regarding the intraoperative MAP target in high-risk hypertensive patients scheduled for elective abdominal surgery.

Development of a Randomized Trial Comparing ICP-Monitor-Based Management of Severe Pediatric Traumatic Brain Injury to Management Based on Imaging and Clinical Examination Without ICP Monitoring-Research Algorithms.

The efficacy of our current approach to incorporating intracranial pressure (ICP) data into pediatric severe traumatic brain injury (sTBI) management is incompletely understood, lacking data from multicenter, prospective, randomized studies. The National Institutes of Health-supported Benchmark Evidence from Latin America-Treatment of Raised Intracranial Pressure-Pediatrics trial will compare outcomes from pediatric sTBI of a management protocol based on ICP monitoring vs 1 based on imaging and clinical examination without monitoring. Because no applicable comprehensive management algorithms for either cohort are available, it was necessary to develop them. A consensus conference involving the 21 intensivists and neurosurgeons from the 8 trial sites used Delphi-based methodology to formulate management algorithms for both study cohorts. We included recommendations from the latest Brain Trauma Foundation pediatric sTBI guidelines and the consensus-based adult algorithms (Seattle International Brain Injury Consensus Conference/Consensus Revised Imaging and Clinical Examination) wherever relevant. We used a consensus threshold of 80%. We developed comprehensive management algorithms for monitored and nonmonitored cohort children with sTBI. We defined suspected intracranial hypertension for the nonmonitored group, set minimum number and timing of computed tomography scans, specified minimal age-adjusted mean arterial pressure and cerebral perfusion pressure targets, defined clinical neuroworsening, described minimal requisites for intensive care unit management, produced tiered management algorithms for both groups, and listed treatments not routinely used. We will study these protocols in the Benchmark Evidence from Latin America-Treatment of Raised Intracranial Pressure-Pediatrics trial in low- and middle-income countries. Second, we present them here for consideration as prototype pediatric sTBI management algorithms in the absence of published alternatives, acknowledging their limited evidentiary status. Therefore, herein, we describe our study design only, not recommended treatment protocols.

High versus low mean arterial pressure targets after out-of-hospital cardiac arrest: a meta-analysis of randomized controlled trials

Abstract Background Out-of-hospital cardiac arrest (OHCA) is a significant healthcare burden, with an average global incidence of 55 per 100,000 person-years among adults. OHCA patients require blood pressure support to maintain effective mean arterial pressure (MAP) for cerebral reperfusion, which is usually achieved by intravascular fluids and vasopressors in the intensive care unit (ICU). Targeting a specific MAP has been evaluated as a treatment strategy after OHCA; however, the current evidence lacks clear guidelines regarding the optimal MAP target after OHCA. Purpose We aim to evaluate the efficacy of targeting a high MAP (&amp;gt;70 mmHg) versus a low MAP target (&amp;lt; 65 mmHg) after OHCA resuscitation. Methods We conducted a systematic review and meta-analysis synthesizing randomized controlled trials (RCTs), which were retrieved by systematically searching: PubMed, EMBASE, Web of Science, SCOPUS, and Cochrane through January 18th, 2023. Continuous and dichotomous outcomes were pooled using mean difference (MD) and risk ratio (RR) along with confidence interval (CI), using Revman V. 5.4 software. Our review protocol was prospectively published on PROSPERO with ID: CRD42023395333. Results Four RCTs with a total of 1070 patients (531 in the high MAP target group and 534 in the low MAP target group) were included in our analysis. High MAP target was significantly associated with decreased ICU length of stay (MD: -0.78 with a 95 CI [-1.54, -0.02], P= .04) and mechanical ventilation duration (MD: -0.91 with a 95 CI of [-1.51, -0.31], P= .003). However, There was no difference between targeting a high MAP versus low MAP regarding all-cause mortality (RR: 1.07 with a 95% CI [0.91, 1.27], P= 0.4), favorable neurological recovery (cerebral categories scale (CPC) ≤ 2) (RR: 1.02 with a 95% CI [0.93, 1.13], P= 0.68), and neuron-specific enolase (NSE) at 48 hours (MD: 0.54 with 95% CI [-1.67, 2.75], P = 0.63), the incidence of adverse events, including any bleeding (RR: 0.89 with a 95% CI [0.69, 1.36], P= 0.39); arrhythmia (RR: 0.91 with a 95% CI [0.46, 1.82], P= 0.79), or acute kidney injury (RR: 0.80 with a 95% CI [0.36, 1.76] and P = 0.58). Conclusion In patients with OHCA who have been resuscitated, targeting a higher MAP significantly reduced the ICU length of stay and mechanical ventilation, implying potential clinical benefit with an acceptable safety margin. However, there was no difference between targeting a high MAP versus a low MAP regarding all-cause mortality, favorable neurological recovery, and NSE. Therefore, further RCTs are still warranted to elucidate the potential clinical benefit of targeting a high MAP after OHCA before endorsement in clinical practice.Figure 1Figure 2

Abstract 100: Blood Pressure Targets and Hemodynamics According to Initial Blood Lactate Levels in Patients With Comatose Out-of-Hospital Cardiac Arrest - A Substudy of the BOX Trial

Out-of-hospital cardiac arrest (OHCA) patients are often circulatory unstable and have high mortality in the first days following resuscitation. An increase in lactate will reflect the severity and duration of hypoperfusion in out-of-hospital cardiac arrest (OHCA). Further, the severity of hypoperfusion could modify the effect on survival and neurological injury of different mean arterial blood pressure (MAP) targets. In this sub-study of the BOX trial, adults successfully resuscitated comatose OHCA patients (n=789) with a presumed cardiac cause were randomized to a MAP 63 mmHg vs. 77 mmHg. Patients were arbitrarily grouped in low-lactate: &lt;25%, medium-lactate: 25%-75%, and high &gt;75 % according to blood lactate levels at hospital arrival as a surrogate of severity of hypoperfusion. Invasive evaluations were performed using an arterial line and pulmonary artery catheter (PAC). Logistic regression analysis evaluated whether lactate levels (as continuous and categorical) modify the effect of MAP targets on 1-year mortality. The three lactate groups were: low-lactate: &lt;2.9 mmol/L, medium-lactate: 2.9-7.9 mmol/L, and high-lactate &gt;7.9 mmol/L. The vasoactive inotropic score was higher with increasing initial lactate level with the largest difference at 6 hours (low-lactate: 7.8 (95%CI: 5.7 - 10.1) vs. high-lactate: 16.4 (95%CI: 13.4 - 19.6). No difference in the cardiac index or systemic vascular resistance was observed between lactate groups. The initial lactate level modified the effect of the two MAP targets (p=0.044), with a tendency to higher mortality for high-lactate patients if the MAP target were 77 mmHg (odds ratio: 1.7 (95%CI: 0.9-3.0, p=0.08). Comatose OHCA patients with high initial lactate levels required more vasoactive drugs on the first two days of ICU admission to meet the blood pressure target and have a poorer prognosis. The results do not support a higher MAP target benefit for patients with an initial high lactate level in the first 48 hours.

Cerebral autoregulation-based mean arterial pressure targets and delirium in critically ill adults without brain injury: a retrospective cohort study.

Cerebral autoregulation (CA) is a mechanism that acts to maintain consistent cerebral perfusion across a range of blood pressures, and impaired CA is associated with delirium. Individualized CA-derived blood pressure targets are poorly characterized in critically ill patients and the association with intensive care unit (ICU) delirium is unknown. Our objectives were to characterize optimal mean arterial pressure (MAPopt) ranges in critically ill adults without brain injury and determine whether deviations from these targets contribute to ICU delirium. We performed a retrospective cohort analysis of patients with shock of any etiology and/or respiratory failure requiring invasive mechanical ventilation, without a neurologic admitting diagnosis. Patients were screened daily for delirium. Cerebral oximetry and mean arterial pressure data were captured for the first 24hr from enrolment. Forty-two patients with invasive blood pressure monitoring data were analyzed. Optimal mean arterial pressure targets ranged from 55 to 100mmHg. Optimal mean arterial pressure values were not significantly different based on history of hypertension or delirium status, and delirium was not associated with deviations from MAPopt. Nevertheless, the majority (69%) of blood pressure targets exceeded the current 65mmHg Surviving Sepsis guidelines. We observed that MAPopt targets across patients were highly variable, but did not observe an association with the incidence of delirium. Studies designed to evaluate the impact on neurologic outcomes are needed to understand the association with individualized mean arterial pressure targets in the ICU. ClinicalTrials.gov (NCT02344043); first submitted 22 January 2015.

Nurse management of noradrenaline infusions in intensive care units: An observational study

BackgroundIntensive care nurse management of noradrenaline (norepinephrine) infusions is a common and essential clinical competency for patient haemodynamic support. Nurses titrate and wean noradrenaline infusions to a target blood pressure in a dynamic, high-risk, and unpredictable environment. Titration and weaning are complex interventions, and blood pressure goals are often variable. ObjectivesThe aim was to examine how nurses used blood pressure targets when escalating, weaning, and titrating noradrenaline in intensive care patients admitted for haemodynamic management and explore patient blood pressure responses to changes in noradrenaline doses. MethodsIn this naturalistic observational study, noradrenaline dose changes were classified as escalation, weaning, and titration changes and analysed to explore nursing practice. The study was undertaken in two adult medical/surgical intensive care units in Melbourne, Australia. Participants included intensive care nurses and patients who received noradrenaline infusions for haemodynamic support. ResultsObservations of 14 nurse–patient dyads provided 25 h of blood pressure and noradrenaline dose data. Patient participants received weight-adjusted maximum noradrenaline doses of between 0.06 mcg/kg/min and 0.87 mcg/kg/minute, with those in the escalation group receiving dose increases of up to 5 mcg to achieve blood pressure goals. During weaning, patients maintained or increased their blood pressure as noradrenaline doses were decreased. Nurses consistently maintained blood pressures at higher than target goals, and despite constant fluctuations, they only documented blood pressure readings hourly. ConclusionsIntensive care nurses managed noradrenaline to achieve mean arterial pressure targets that were variable and not evidence based. The disconnection between observed blood pressure fluctuations and nurse documentation of patient blood pressures was reflected in titration practices. Discrepancies between documented and actual blood pressures raised issues about data used by nurses and doctors to inform clinical practice on noradrenaline management.

Treatment effects of blood pressure targets and hemodynamics according to initial blood lactate levels in comatose out-of-hospital cardiac arrest patients – A sub study of the BOX trial

BackgroundOut-of-hospital cardiac arrest (OHCA) survivors remaining comatose are often circulatory unstable with high mortality in the first days following resuscitation. Elevated lactate will reflect the severity and duration of hypoperfusion in cardiac arrest. Further, the severity of hypoperfusion could modify the effect on survival of different mean arterial blood pressure (MAP) targets. MethodsIn this sub-study of the BOX trial, adult successfully resuscitated comatose OHCA patients (n = 789) with a presumed cardiac cause were randomized to a MAP target of 63 mmHg vs. 77 mmHg. Patients were arbitrarily grouped in low-lactate: <25% of sample, medium-lactate: 25%–75%, and high >75 percentile according to blood lactate levels at hospital arrival as a surrogate of the severity of hypoperfusion. Invasive hemodynamic evaluations were performed using an arterial catheter and pulmonary artery catheter (PAC), and data from admission to 48 hours (h) were recorded. Logistic regression analysis evaluated whether lactate levels (as continuous and categorical) modify the effect of MAP targets on mortality at 365 days. ResultsThe three lactate groups had initial lactate levels of low-lactate: <2.9 mmol/L, medium-lactate: 2.9–7.9 mmol/L, and high-lactate > 7.9 mmol/L. All patients were randomized to a 63 mmHg or 77 mmHg MAP target. The proportion of patients in the high-MAP target group was 100/201 (50%), 178/388 (46%), and 114/197 (58%) for low, medium, and high-lactate groups respectively. At admission, the high-lactate groups had a lower MAP compared to the medium-lactate (2.6 mmHg (95% CI: 0.1–5.0 mmHg, p = 0.02), and the low-lactate group, (3.6 mmHg (95% CI: 0.8–6.5 mmHg, p < 0.01). Accordingly, the vasoactive inotropic score was 79% (95%CI: 42%–124%%) higher with increasing initial lactate level (High-lactate vs. low-lactate) with the largest difference at 6 hours (110.6% (95%CI: 54.4%–187.2%) higher in high-lactate patients). No difference in the cardiac index or systemic vascular resistance was observed between lactate groups. The initial lactate level (continuous) modified the effect of the two MAP targets (p = 0.04). In the highest lactate group, the mortality was 100/197 (51%), and with an odds ratio (OR): 1.7 (95%CI: 0.9–3.0) if randomized to MAP 77 mmHg compared to MAP 63 mmHg. In the lowest lactate group, the mortality was 35/201(17%) and similar if randomized to a MAP target of 77 mmHg (OR: 1.1 (95% CI: 0.5–2.3)). ConclusionComatose OHCA patients with high initial lactate levels required more vasoactive drugs on the first two days of ICU admission to meet the blood pressure target and had a poorer prognosis. No indication that aiming for a higher MAP target is beneficial in patients with an initial high lactate level was found, however, given the post-hoc nature of this study, these results should be considered hypothesis-generating

Association between diastolic blood pressure during the first 24 h and 28-day mortality in patients with septic shock: a retrospective observational study

BackgroundAlthough the mean arterial pressure (MAP) target of 65 mmHg was achieved, diastolic blood pressure (DBP) was still low in some septic shock patients. The effects of DBP on the prognosis and optimal target for patients with septic shock are unclear. We sought to investigate the relationship between DBP and 28-day mortality in septic shock patients.MethodsIn this retrospective observational study, we obtained data from the Chinese Database in Intensive Care (CDIC). We included patients with an admission diagnosis of septic shock and shock was controlled. DBP was measured every 1 h, and the mean DBP during the first 24 h (mDBP24h) was recorded. The primary outcome was 28-day mortality. Multivariable logistic regression determined the relationship between mDBP24h and 28-day mortality.ResultsIn total, 1251 patients were finally included. The 28-day mortality of included septic shock patients was 28.3%. The mDBP24h, not mSBP24h, was higher among 28-day survivors compared with non-survivors. 28-day mortality was inversely associated with mDBP24h (unadjusted OR 0.814 per 10 mmHg higher mDBP24h, P = 0.003), with a stepwise increase in 28-day mortality at lower mDBP24h. The 28-day mortality of patients with mDBP24h < 59 mmHg had an absolute risk reduction of 9.4% (P = 0.001). And mDBP24h < 59 mmHg was the remaining high risk factor inversely associated with 28-day mortality after multivariable adjustment (adjusted OR 1.915, 95% CI 1.037–3.536, P = 0.038), while mMAP24h and mSBP24h were not.ConclusionIn patients with septic shock after initial resuscitation, we observed an inverse association between mDBP24h and 28-day mortality. The poor outcomes in patients with mDBP24h < 59 mmHg provide indirect evidence supporting a further DBP goal of 59 mmHg for patients with septic shock after MAP of 65 mmHg was achieved.

Optimising Intraoperative Fluid Management in Patients Treated with Adolescent Idiopathic Scoliosis-A Novel Strategy for Improving Outcomes.

Scoliosis surgery is a challenge for the entire team in terms of safety, and its accomplishment requires the utilization of advanced monitoring technologies. A prospective, single centre, non-randomised controlled cohort study, was designed to assess the efficacy of protocolised intraoperative haemodynamic monitoring and goal-directed therapy in relation to patient outcomes following posterior fusion surgery for adolescent idiopathic scoliosis (AIS). The control group (n = 35, mean age: 15 years) received standard blood pressure management during the surgical procedure, whereas the intervention group (n = 35, mean age: 14 years) underwent minimally invasive haemodynamic monitoring. Arterial pulse contour analysis (APCO) devices were employed, along with goal-directed therapy protocol centered on achieving target mean arterial pressure and stroke volume. This was facilitated through the application of crystalloid boluses, ephedrine, and noradrenaline. The intervention group was subjected to a comprehensive protocol following Enhanced Recovery After Surgery (ERAS) principles. Remarkably, the intervention group exhibited notable advantages (p < 0.05), including reduced hospital stay durations (median 7 days vs. 10), shorter episodes of hypotension (mean arterial pressure < 60 mmHg-median 8 vs. 40 min), lesser declines in postoperative haemoglobin levels (-2.36 g/dl vs. -3.83 g/dl), and quicker extubation times. These compelling findings strongly imply that the integration of targeted interventions during the intraoperative care of AIS patients undergoing posterior fusion enhance a set of treatment outcomes.

Effect of rScO2-Guided Blood Pressure Management on Postoperative Complications in Elderly Patients After Major Noncardiac Surgery: Protocol for a Randomized Controlled Trial.

Postoperative complications are common after major surgical procedures, leading to increased morbidity and mortality. Regional cerebral oxygen saturation (rScO2) reflects cerebral and global perfusion, and thus it can be used to guide hemodynamic management. We aim to explore the effect of rScO2-guided blood pressure management strategy on postoperative major complications in older adults who undergo major noncardiac surgery. This randomized controlled clinical trial includes a total of 400 elderly patients receiving major noncardiac surgery and general anesthesia. Patients will be randomized (1:1) to one of two blood pressure management groups: a standard care group (targeting mean arterial pressure >65 mmHg or within 20% of baseline value), and a rScO2-guided group (absolute value of rScO2 >60% or decrease in rScO2 <10% of baseline). The primary outcome is the composite outcome of major complications (including infectious, respiratory, neurologic, cardiovascular, renal, thromboembolic gastrointestinal, and surgical complications) and deaths within the first 7 days after surgery. Secondary outcomes include the individual components of the primary outcome by day 7 after surgery and 30-day mortality. Data will be analyzed in the modified intention-to-treat population. This study will provide evidence for improving postoperative outcomes using the rScO2-guided blood pressure management among older adults who undergo major noncardiac surgery. Chinese Clinical Trial Registry (Identifier: ChiCTR2200060816).

Blood Pressure Targets for Out-of-Hospital Cardiac Arrest: A Systematic Review and Meta-Analysis.

With ideal mean arterial pressure (MAP) targets in resuscitated out-of-hospital cardiac arrest (OHCA) patients unknown, we performed a meta-analysis of randomised controlled trials (RCTs) to compare the effects of higher versus lower MAP targets. We searched four databases until 1 May 2023 for RCTs reporting the effects of higher MAP targets (>70 mmHg) in resuscitated OHCA patients and conducted random-effects meta-analyses. The primary outcome was mortality while secondary outcomes were neurological evaluations, arrhythmias, acute kidney injury, and durations of mechanical ventilation and ICU stay. We conducted inverse-variance weighted strata-level meta-regression against a proportion of non-survivors to assess differences between reported MAPs. We also conducted a trial sequential analysis of RCTs. Four RCTs were included. Higher MAP was not associated with reduced mortality (OR: 1.09, 95%-CI: 0.84 to 1.42, p = 0.51), or improved neurological outcomes (OR: 0.99, 95%-CI: 0.77 to 1.27, p = 0.92). Such findings were consistent despite additional sensitivity analyses. Our robust variance strata-level meta-regression revealed no significant associations between mean MAP and the proportion of non-survivors (B: 0.029, 95%-CI: -0.023 to 0.081, p = 0.162), and trial sequential analysis revealed no meaningful survival benefit for higher MAPs. A higher MAP target was not significantly associated with improved mortality and neurological outcomes in resuscitated OHCA patients.