Mean Arterial Pressure and Discharge Outcomes in Severe Pediatric Traumatic Brain Injury

Cardiovascular responses as predictors of mortality in children with acute brain injury

BACKGROUND

Investigate the utility of cardiovascular responses such as heart rate (HR), blood pressure (BP), and heart rate variability (HRV) in the prognosis of children with acute acquired brain injury (ABI).

METHODS

Children under 18 years with severe acute acquired brain injury (ABI) who survived at least 12 h after PICU admission were included in a prospective observational cohort in a tertiary academic PICU. Physiological variables, neurological data, laboratory tests (chemistry and hematology), and medications were recorded within 12 h of admission. Linear and nonlinear HRV indices, CT scans, PICU scores, and survival rates were evaluated.

RESULTS

Seventy-two children, median age 10.7 years (IQR 4.1-13.6), were eligible for the study; 28 (38.9%) were diagnosed with brain death (BD). Tachycardia, SBP and MBP < 5th percentile, and MBP and DBP> 99th percentile were significantly associated with mortality. Poincaré SD1/SD2 was significantly associated with mortality after adjusting for age, sex and ongoing medication.

CONCLUSION

Tachycardia, systolic hypotension and median hypo and hypertension were associated to mortality in children with severe ABI. While further validation through larger, multicenter studies is necessary, the Poincaré SD1/SD2 ratio has shown promise as a prognostic tool for predicting mortality in children with severe ABI.

IMPACT STATEMENT

This study explores cardiovascular changes, including heart rate and blood pressure, and linear/nonlinear HRV measures using ECG at 1000 Hz, and compare them with other prognostic factors like brain tomography and PICU scores. Tachycardia, hypo/hypertension in the early hours after admission are linked to early mortality in children with severe traumatic and non-traumatic brain injury. Linear/non-linear measures of HRV were also related to survival. Higher HRV values indicating better survival chances. We identified Poincaré SD1/SD2 ratio as a promising tool for predicting mortality in children with severe ABI.

Predicting and improving outcome in severe pediatric traumatic brain injury

INTRODUCTION

Severe pediatric traumatic brain injury (spTBI), including abusive head trauma (AHT) in young children, is a major public health problem. Long-term consequences of spTBI include a large variety of physical, neurological, biological, cognitive, behavioral and social deficits and impairments.

AREAS COVERED

The present narrative review summarizes studies and reviews published from January 2019 to February 2024 on spTBI. Significant papers published before 2019 were also included. The article gives coverage to the causes of spTBI, its epidemiology and fatality rates; disparities, inequalities, and socioeconomic factors; critical care; outcomes; and interventions.

EXPERT OPINION

There are disparities between countries and according to socio-economic factors regarding causes, treatments and outcomes of spTBI. AHT has an overall poor outcome. Adherence to critical care guidelines is imperfect and the evidence-base of guidelines needs further investigations. Neuroimaging and biomarker predictors of outcomes is a rapidly evolving domain. Long-term cognitive, behavioral and psychosocial difficulties are the most prevalent and disabling. Their investigation should make a clear distinction between objective (clinical examination, cognitive tests, facts) and subjective measures (estimations using patient- and proxy-reported questionnaires), considering possible common source bias in reported difficulties. Family/caregiver-focused interventions, ecological approaches, and use of technology in delivery of interventions are recommended to improve long-term difficulties after spTBI.

Optimal target mean arterial pressure for patients with sepsis-associated encephalopathy: a retrospective cohort study

BACKGROUND

Sepsis-associated encephalopathy (SAE) patients often experience changes in intracranial pressure and impaired cerebral autoregulation. Mean arterial pressure (MAP) plays a crucial role in cerebral perfusion pressure, but its relationship with mortality in SAE patients remains unclear. This study aims to investigate the relationship between MAP and the risk of 28-day and in-hospital mortality in SAE patients, providing clinicians with the optimal MAP target.

METHODS

We retrospectively collected clinical data of patients diagnosed with SAE on the first day of ICU admission from the MIMIC-IV (v2.2) database. Patients were divided into four groups based on MAP quartiles. Kruskal-Wallis H test and Chi-square test were used to compare clinical characteristics among the groups. Restricted cubic spline and segmented Cox regression models, both unadjusted and adjusted for multiple variables, were employed to elucidate the relationship between MAP and the risk of 28-day and in-hospital mortality in SAE patients and to identify the optimal MAP. Subgroup analyses were conducted to assess the stability of the results.

RESULTS

A total of 3,816 SAE patients were included. The Q1 group had higher rates of acute kidney injury and vasoactive drug use on the first day of ICU admission compared to other groups (P < 0.01). The Q1 and Q4 groups had longer ICU and hospital stays (P < 0.01). The 28-day and in-hospital mortality rates were highest in the Q1 group and lowest in the Q3 group. Multivariable adjustment restricted cubic spline curves indicated a nonlinear relationship between MAP and mortality risk (P for nonlinearity < 0.05). The MAP ranges associated with HRs below 1 for 28-day and in-hospital mortality were 74.6-90.2 mmHg and 74.6-89.3 mmHg, respectively.The inflection point for mortality risk, determined by the minimum hazard ratio (HR), was identified at a MAP of 81.5 mmHg. The multivariable adjusted segmented Cox regression models showed that for MAP < 81.5 mmHg, an increase in MAP was associated with a decreased risk of 28-day and in-hospital mortality (P < 0.05). In Model 4, each 5 mmHg increase in MAP was associated with a 15% decrease in 28-day mortality risk (HR: 0.85, 95% CI: 0.79-0.91, p < 0.05) and a 14% decrease in in-hospital mortality risk (HR: 0.86, 95% CI: 0.80-0.93, p < 0.05). However, for MAP ≥ 81.5 mmHg, there was no significant association between MAP and mortality risk (P > 0.05). Subgroup analyses based on age, congestive heart failure, use of vasoactive drugs, and acute kidney injury showed consistent results across different subgroups.Subsequent analysis of SAE patients with septic shock also showed results similar to those of the original cohort.However, for comatose SAE patients (GCS ≤ 8), there was a negative correlation between MAP and the risk of 28-day and in-hospital mortality when MAP was < 81.5 mmHg, but a positive correlation when MAP was ≥ 81.5 mmHg in adjusted models 2 and 4.

CONCLUSION

There is a nonlinear relationship between MAP and the risk of 28-day and in-hospital mortality in SAE patients. The optimal MAP target for SAE patients in clinical practice appears to be 81.5 mmHg.

The Australian Traumatic Brain Injury Initiative: Systematic Review of Clinical Factors Associated with Outcomes in People with Moderate-Severe Traumatic Brain Injury

The aim of the Australian Traumatic Brain Injury Initiative (AUS-TBI) is to design a data dictionary to inform data collection and facilitate prediction of outcomes for moderate-severe traumatic brain injury (TBI) across Australia. The process has engaged diverse stakeholders across six areas: social, health, clinical, biological, acute interventions, and long-term outcomes. Here, we report the results of the clinical review. Standardized searches were implemented across databases to April 2022. English-language reports of studies evaluating an association between a clinical factor and any clinical outcome in at least 100 patients with moderate-severe TBI were included. Abstracts, and full-text records, were independently screened by at least two reviewers in Covidence. The findings were assessed through a consensus process to determine inclusion in the AUS-TBI data resource. The searches retrieved 22,441 records, of which 1137 were screened at full text and 313 papers were included. The clinical outcomes identified were predominantly measures of survival and disability. The clinical predictors most frequently associated with these outcomes were the Glasgow Coma Scale, pupil reactivity, and blood pressure measures. Following discussion with an expert consensus group, 15 were recommended for inclusion in the data dictionary. This review identified numerous studies evaluating associations between clinical factors and outcomes in patients with moderate-severe TBI. A small number of factors were reported consistently, however, how and when these factors were assessed varied. The findings of this review and the subsequent consensus process have informed the development of an evidence-informed data dictionary for moderate-severe TBI in Australia.

Cardiovascular events in children with brain injury: A systematic review

BACKGROUND

Brain injury is a leading cause of morbidity and mortality in the pediatric population. Neurogenic stunned cardiomyopathy is a complication associated with several neurological conditions that can lead to worse outcomes. It presents as alterations in blood pressure, cardiac rhythm disturbances and the increase in cardiac injury biomarkers. This systematic review aims to assess the hemodynamic consequences of brain injury in the pediatric population to identify better management strategies and improve outcomes.

METHODS

An electronic literature search was performed in Pubmed, Scopus and WebOfScience, up until October 3rd, 2022. The selected articles underwent quality assessment using the National Heart, Lung and Blood Institute tools for cohort and case-control studies.

RESULTS

This systematic review includes thirteen articles on the effects of brain injury in arterial pressure, rhythm disturbances and biomarkers of myocardial injury. These studies showed the following key results: both hypotension and hypertension are associated with worse outcomes; brain injury could be related to longer QTc intervals; neurogenic stunned cardiomyopathy was a common found after brain injury.

CONCLUSION

This is the first systematic review to report cardiovascular abnormalities arising from brain injury in children. An early arterial pressure, electrocardiographic and echocardiographic evaluation, as well as the measure of serum biomarkers for myocardial injury, can be critical in identifying poor prognostic factors. Further research is required to understand the implications of our findings in clinical practice.

Approaches to neuroprotection in pediatric neurocritical care

Acute neurologic injuries represent a common cause of morbidity and mortality in children presenting to the pediatric intensive care unit. After primary neurologic insults, there may be cerebral brain tissue that remains at risk of secondary insults, which can lead to worsening neurologic injury and unfavorable outcomes. A fundamental goal of pediatric neurocritical care is to mitigate the impact of secondary neurologic injury and improve neurologic outcomes for critically ill children. This review describes the physiologic framework by which strategies in pediatric neurocritical care are designed to reduce the impact of secondary brain injury and improve functional outcomes. Here, we present current and emerging strategies for optimizing neuroprotective strategies in critically ill children.

Blood Pressure Control in Traumatic Subdural Hematomas

Background There is debate over optimal systolic blood pressure (SBP) after traumatic subdural hematoma. Increased SBP has the benefit of increasing cerebral perfusion pressure and limiting the detrimental secondary effects of traumatic brain injury but poses a risk of hematoma expansion. While prior studies have shown that SBP<90mmHg is associated with worsened morbidity and mortality in subdural hematoma patients, clinical guidelines and expert opinion have differing initial SBP goals. The aim of this study is to leverage a large database to determine the effects of two such goals, namely SBP 100-150mmHg versus SBP<180mmHg in this patient population. Methods A de-identified database network (TriNetX Research Network) was used to retrospectively query all patients with a first instance diagnosis of acute traumatic SDH, who also had a recorded GCS, with maintenance of SBP 100-150 within the first 24 hours (cohort 1) versus patients with an SBP<180 (cohort 2). Data came from 68 health care organizations (HCOs) with a total of 105,897,964 patients on 9/1/2022. The primary outcome of interest was mortality within 30 days. Secondary outcomes include gastrostomy tube placement, craniotomy/craniectomy/burr hole drainage, venous thromboembolism, ischemic stroke, myocardial infarction, seizure, falls, cardiac arrest, and acute kidney injury within 30 days. Cohorts were propensity-score matched for confounders. Results After propensity score matching, 1,243 patients were identified in each cohort. Age at index was 57.97+/-23.21 years and 58.28+/-22.35 years for cohorts 1 and 2, respectively. Mortality was seen in 243 patients (19.756%) vs. 209 (16.992%) (OR 1.203, 95% CI (0.98,1.476), p=0.0767) in cohorts 1 and 2, respectively. There was no statistical difference in secondary outcomes. Conclusion The results of this study demonstrate that the primary outcome of mortality at 30 days is not statistically different in acute traumatic SDH patients, whether their SBP is kept at 100-150 or below 180. Likewise, it shows no statistical difference in the subsequent incidence of gastrostomy tube placement, craniotomy/craniectomy/burr holes, venous thromboembolism, ischemic stroke, myocardial infarction, seizure, falls, or acute kidney injury.

Hemodynamic instability during connection to continuous kidney replacement therapy in critically ill pediatric patients

BACKGROUND

Emerging data suggest evidence of organ hypoperfusion during continuous kidney replacement therapy (CKRT). To facilitate kidney and global recovery, we must understand the hemodynamic risks associated with CKRT. We aimed to investigate frequency of hemodynamic instability and association with patient outcomes in pediatric CKRT.

METHODS

In a single-center study of CKRT patients between September 2016 and October 2018, we collected hemodynamic data using archived high-resolution physiologic data before and after connection. Primary outcome was hypotension defined as ≥ 20% decrease in baseline mean arterial pressure (MAP) for ≥ 2 consecutive minutes in the 60 min following connection. Secondary outcomes were tachycardia (≥ 20% increase in heart rate (HR)) and hemodynamic interventions.

RESULTS

Seventy-one patients median age 54 months (IQR 7-144), weight 16.7 kg (IQR 8-41), on hemodiafiltration had 304 filter connections, 4 (IQR 1-7) filters per patient; the median duration of CKRT was 9 days (IQR 3-20). The most common CKRT indication was AKI with fluid overload (48/71, 69%). There were 78 (27%) hypotension and 42 (14%) tachycardia events; cumulative duration of hypotension was 14 min IQR (3-31.75). Teams provided intervention in 17/304 (6%) of connections. Pediatric Logistic Organ Dysfunction 2 was the only independent predictor of hypotension (aOR 2.12 (CI 1.02-4.41)).

CONCLUSIONS

One in four and one in six pediatric CKRT filter connections were complicated by hypotension and tachycardia, respectively. Higher illness severity at CKRT initiation was independently associated with hypotension. Impact of CKRT-associated hemodynamic instability on global patient outcomes requires further targeted study. A higher resolution version of the Graphical abstract is available as Supplementary information.

Associations of initial haemodynamic profiles and neurological outcomes in children with traumatic brain injury: a secondary analysis

INTRODUCTION

Initial low systolic blood pressure (SBP) in paediatric traumatic brain injury (TBI) is associated with mortality. There is limited literature on how other haemodynamic parameters including heart rate (HR); diastolic blood pressure (DBP); mean arterial pressure (MAP); and shock index, paediatric age-adjusted (SIPA) affect not only mortality but also long-term neurological outcomes in paediatric TBI. We aimed to analyse the associations of these haemodynamic variables (HR, SBP, MAP, DBP and SIPA) with mortality and long-term neurological outcomes in isolated moderate-to-severe paediatric TBI.

METHODS

This was a secondary analysis of our primary study that analysed the association of TBI-associated coagulopathy with mortality and neurological outcome in isolated, moderate-to-severe paediatric head injury. A trauma registry-based, retrospective study of children <18 years old who presented to the emergency department with isolated, moderate-to-severe TBI from January 2010 to December 2016 was conducted. The association between initial haemodynamic variables and less favourable outcomes using Glasgow Outcome Scale-Extended Paediatric) at 6 months post injury was analysed using logistic regression.

RESULTS

Among 152 children analysed, initial systolic and diastolic hypotension (<5th percentile) (OR) for SBP 11.40, 95% CI 3.60 to 36.05, p<0.001; OR for DBP 15.75, 95% CI 3.09 to 80.21, p<0.001) and Glasgow Coma Scale scores <8 (OR 14.50, 95% CI 3.65 to 57.55, p<0.001) were associated with 'moderate-to-severe neurological disabilities', 'vegetative state' and 'death'. After adjusting for confounders, only SBP was significant (adjusted OR 5.68, 95% CI 1.40 to 23.08, p=0.015).

CONCLUSIONS

Initial systolic hypotension was independently associated with mortality and moderate-to-severe neurological deficits at 6 months post injury. Further work is required to understand if early correction of hypotension will improve long-term outcomes.