Traditional systolic blood pressure targets underestimate hypotension-induced secondary brain injury

Abstract Background In neurocritically ill patients, one early mechanism behind secondary brain injury is low systemic blood pressure resulting in inadequate cerebral perfusion and consequent hypoxia. Intuitively, higher partial pressures of arterial oxygen (PaO2) could be protective in case of inadequate cerebral circulation related to hemodynamic instability. Study purpose We examined whether the association between PaO2 and mortality is different in patients with low compared to normal and high mean arterial pressure (MAP) in patients after various types of brain injury. Methods We screened the Finnish Intensive Care Consortium database for mechanically ventilated adult (≥ 18) brain injury patients treated in several tertiary intensive care units (ICUs) between 2003 and 2013. Admission diagnoses included traumatic brain injury, cardiac arrest, subarachnoid and intracranial hemorrhage, and acute ischemic stroke. The primary exposures of interest were PaO2 (recorded in connection with the lowest measured PaO2/fraction of inspired oxygen ratio) and the lowest MAP, recorded during the first 24 h in the ICU. PaO2 was grouped as follows: hypoxemia (< 8.2 kPa, the lowest 10th percentile), normoxemia (8.2–18.3 kPa), and hyperoxemia (> 18.3 kPa, the highest 10th percentile), and MAP was divided into equally sized tertiles (< 60, 60–68, and > 68 mmHg). The primary outcome was 1-year mortality. We tested the association between hyperoxemia, MAP, and mortality with a multivariable logistic regression model, including the PaO2, MAP, and interaction of PaO2*MAP, adjusting for age, admission diagnosis, premorbid physical performance, vasoactive use, intracranial pressure monitoring use, and disease severity. The relationship between predicted 1-year mortality and PaO2 was visualized with locally weighted scatterplot smoothing curves (Loess) for different MAP levels. Results From a total of 8290 patients, 3912 (47%) were dead at 1 year. PaO2 was not an independent predictor of mortality: the odds ratio (OR) for hyperoxemia was 1.16 (95% CI 0.85–1.59) and for hypoxemia 1.24 (95% CI 0.96–1.61) compared to normoxemia. Higher MAP predicted lower mortality: OR for MAP 60–68 mmHg was 0.73 (95% CI 0.64–0.84) and for MAP > 68 mmHg 0.80 (95% CI 0.69–0.92) compared to MAP < 60 mmHg. The interaction term PaO2*MAP was nonsignificant. In Loess visualization, the relationship between PaO2 and predicted mortality appeared similar in all MAP tertiles. Conclusions During the first 24 h of ICU treatment in mechanically ventilated brain injured patients, the association between PaO2 and mortality was not different in patients with low compared to normal MAP.

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5958The relation between systolic blood pressure and mortality in hypertensive patients with different blood pressure targets: the J-curve revisited

European Heart Journal ◽

10.1093/eurheartj/ehx493.5958 ◽

2017 ◽

Vol 38 (suppl_1) ◽

Author(s):

T.F. Brouwer ◽

J.T. Vehmeijer ◽

D.N. Kalkman ◽

W.R. Berger ◽

B.J. Van Den Born ◽

...

Keyword(s):

Blood Pressure ◽

Systolic Blood Pressure ◽

Hypertensive Patients ◽

Blood Pressure Targets ◽

J Curve

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Systolic blood pressure lower than the heart rate indicates a poor outcome in patients with severe isolated traumatic brain injury: A cross-sectional study

International Journal of Surgery ◽

10.1016/j.ijsu.2018.11.030 ◽

2019 ◽

Vol 61 ◽

pp. 48-52 ◽

Cited By ~ 1

Author(s):

Jin-Fu Huang ◽

Yu-Chin Tsai ◽

Cheng-Shyuan Rau ◽

Shiun-Yuan Hsu ◽

Peng-Chen Chien ◽

...

Keyword(s):

Blood Pressure ◽

Traumatic Brain Injury ◽

Heart Rate ◽

Brain Injury ◽

Systolic Blood Pressure ◽

Cross Sectional Study ◽

Sectional Study ◽

Cross Sectional ◽

Poor Outcome

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Systolic blood pressure targets are too high, meta-analysis suggests

BMJ ◽

10.1136/bmj.j2686 ◽

2017 ◽

pp. j2686

Author(s):

Zosia Kmietowicz

Keyword(s):

Blood Pressure ◽

Systolic Blood Pressure ◽

Meta Analysis ◽

Blood Pressure Targets

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J Curve in Patients Randomly Assigned to Different Systolic Blood Pressure Targets

Circulation ◽

10.1161/circulationaha.117.030342 ◽

2017 ◽

Vol 136 (23) ◽

pp. 2220-2229 ◽

Cited By ~ 21

Author(s):

Deborah N. Kalkman ◽

Tom F. Brouwer ◽

Jim T. Vehmeijer ◽

Wouter R. Berger ◽

Reinoud E. Knops ◽

...

Keyword(s):

Blood Pressure ◽

Systolic Blood Pressure ◽

Blood Pressure Targets ◽

J Curve

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Interarm differences in systolic blood pressure and the risk of dementia and subclinical brain injury

Alzheimer s & Dementia ◽

10.1016/j.jalz.2015.09.006 ◽

2015 ◽

Vol 12 (4) ◽

pp. 438-445 ◽

Cited By ~ 5

Author(s):

Matthew P. Pase ◽

Alexa Beiser ◽

Hugo Aparicio ◽

Charles DeCarli ◽

Ramachandran S. Vasan ◽

...

Keyword(s):

Blood Pressure ◽

Brain Injury ◽

Systolic Blood Pressure

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EVALUATION OF CARDIOVASCULAR DYSREGULATION IN PATIENTS AFTER HEMORRHAGIC STROKE AS A COMPLICATION OF ESSENTIAL HYPERTENSION

Ukrainian Scientific Medical Youth Journal ◽

10.32345/usmyj.3(125).2021.32-43 ◽

2021 ◽

Vol 125 (3) ◽

pp. 32-43

Author(s):

Oleksandr Tkachyshyn

Keyword(s):

Blood Pressure ◽

Traumatic Brain Injury ◽

Essential Hypertension ◽

Brain Injury ◽

Systolic Blood Pressure ◽

Mild Traumatic Brain Injury ◽

Hemorrhagic Stroke ◽

Blood Pressure Monitoring ◽

Main Group ◽

Control Group

The aim of the study was to compare blood pressure and electrocardiogram indices, assessed by their daily monitoring, and anamnestic data on mild traumatic brain injury between a group of patients with essential hypertension ≥6 months after a hemorrhagic stroke and a group of patients with essential hypertension without complications. Materials and methods. The total number of examined patients was 198 people, who were divided into 2 groups: the main (n = 94; age – 54,4±8,8 years, M±σ years) and the control (n = 104; age – 53,7±8,9 years) one. Patients in the main group suffered a hemorrhagic stroke as a complication of essential hypertension ≥6 months ago. The control group included patients with essential hypertension, stage II. In both groups of patients, the parameters of 24-hour ambulatory blood pressure monitoring and electrocardiogram were determined. Results. The indices of 24-hour ambulatory blood pressure monitoring in the main group and the control group were the following ones, respectively: the mean daytime systolic blood pressure was 109,6±1,6 and 121,1±1,1 mm Hg, the minimal one was 74,4±2,0 mm Hg and 82,3±12,5 mm Hg, and the maximal one was 168,2±1,9 and 161,9±1,7 mm Hg, p<0,05. The daytime sigma systolic blood pressure (17,9±0,6) and its average real variability of (11,31±2,52 mm Hg) were bigger in the main group (p<0,05). The daytime index of the hyperbaric load of systolic blood pressure was bigger in the main group: it was 403,6±25,9 against 231,7±12,1 mm Hg×h in the comparison group (p<0,05). The mean, minimum and maximum heart rate at night were significantly lower in the main group (p<0,05). The QTcmin index was significantly lower in the main group in contrast to the control one – 286,28±43,34 and 336,69±22,55, and the QT variance was greater – 232,56±44,55 – in comparison to the control group (188,31±33,67) (p<0,05). From the anamnestic data of patients, a significantly higher prevalence of mild traumatic brain injury was found in 37,4% (35 patients out of 94) in the main group relative to the control one – 13,5% (14 out of 104), p<0,05. Conclusions: The results of the study indicate the larger ranges of blood pressure variability in patients with essential hypertension complicated with hemorrhagic stroke, which can be caused by impaired autoregulation according to the QTc interval data. In combination with the disturbances of cerebral circulation, caused by the injury of the brain due to the hemorrhagic stroke alone or in combination with mild traumatic brain injury episode, such a situation may lead to the development of recurrent stroke.

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Abstract 31: Low versus High Blood Pressure Targets After Out-Of-Hospital Cardiac Arrest

Circulation ◽

10.1161/circ.140.suppl_2.31 ◽

2019 ◽

Vol 140 (Suppl_2) ◽

Author(s):

Pekka Jakkula ◽

Koen Ameloot ◽

Cathy De Deyne ◽

Jo Dens ◽

Matti Reinikainen ◽

...

Keyword(s):

Blood Pressure ◽

Cardiac Arrest ◽

Brain Injury ◽

Neurological Outcome ◽

Neuron Specific Enolase ◽

Cerebral Hypoperfusion ◽

Chronic Hypertension ◽

Blood Pressure Targets ◽

Significant Difference ◽

Hospital Cardiac Arrest

Introduction: The optimal level of blood pressure after out-of-hospital cardiac arrest (OHCA) is unknown. Hypotension may aggravate cerebral hypoperfusion exacerbating the post-anoxic brain injury. On the other hand, excessive vasopressor support may increase myocardial oxygen consumption and induce arrhythmias. We aimed to evaluate the effects of different blood pressure targets on the extent of brain injury and neurological outcome in patients resuscitated from OHCA. Methods: We performed a pooled post hoc analysis of OHCA patients randomised in the Neuroprotect (NCT02541591) and COMACARE (NCT02698917) trials to either mean arterial pressure (MAP) 65 mmHg or 80/85-100 mmHg targets for the first 36 h after ICU admission. We compared the serum neuron-specific enolase (NSE) concentrations between the groups at 24, 48 and 72 h after cardiac arrest and the neurological outcome according to the Cereberal Performance Category (CPC) scale at 6 months. We defined CPC 1-2 as good outcome and CPC 3-5 as poor outcome. In addition, we conducted a two-way analysis of variance to assess the effects of the MAP target and previous chronic hypertension on NSE concentrations. Results: All 224 patients included in the original studies were included in the analysis. Of these, 111 patients were randomised to the MAP 80/85-100 mmHg group and 113 patients to the MAP 65 mmHg group. Patients assigned to the higher MAP target had significantly higher blood pressure levels (p<0.001). We did not find any statistically significant difference in NSE concentrations (Figure 1) or good neurological outcome (50% in the lower MAP group vs. 56% in the higher MAP group, p=0.417) between the intervention groups. We did not observe statistically significant interaction between the MAP target and chronic hypertension for NSE (p=0.437). Conclusion: Targeting MAP 65 mmHg vs. MAP 80/85-100 mmHg after OHCA did not affect the extent of brain injury as determined by NSE concentration or neurological outcome at 6 months.

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