Clinical and Physiological Events That Contribute to the Success Rate of Finding "Optimal" Cerebral Perfusion Pressure in Severe Brain Trauma Patients.

OBJECTIVE: Recently, a concept of an individually targeted level of cerebral perfusion pressure that aims to restore impaired cerebral vasoreactivity has been advocated after traumatic brain injury. The relationship between cerebral perfusion pressure and pressure reactivity index normally is supposed to have a U-shape with its minimum interpreted as the value of "optimal" cerebral perfusion pressure. The aim of this study is to investigate the relation between the absence of the optimal cerebral perfusion pressure curve and physiological variables, clinical factors, and interventions. DESIGN: Retrospective analysis of prospectively collected data. SETTING: Neurocritical care units in two university centers. PATIENTS: Between May 2012 and December 2013, a total of 48 traumatic brain injury patients were studied with real-time annotation of predefined clinical events. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: All patients had continuous monitoring of arterial blood pressure, intracranial pressure, and cerebral perfusion pressure, with real-time calculations of pressure reactivity index and optimal cerebral perfusion pressure using ICM+ software (Cambridge Enterprise, University of Cambridge, Cambridge, UK). Selected clinical events were inserted on a daily basis, including changes in physiological variables, sedativeanalgesic drugs, vasoactive drugs, and medical/surgical therapies for intracranial hypertension. The collected data were divided into 4-hour periods, with the primary outcome being absence of the optimal cerebral perfusion pressure curve. For every period, mean values (± SDs) of arterial blood pressure, intracranial pressure, pressure reactivity index, and other physiological variables were calculated; clinical events were organized using predefined scales. In 28% of all 1,561 periods, an optimal cerebral perfusion pressure curve was absent. A generalized linear mixed model with binary logistic regression was fitted. Absence of slow arterial blood pressure waves (odds ratio, 2.7; p < 0.001), higher pressure reactivity index values (odds ratio, 2.9; p < 0.001), lower amount of sedative-analgesic drugs (odds ratio, 1.9; p = 0.03), higher vasoactive medication dose (odds ratio, 3.2; p = 0.02), no administration of maintenance neuromuscular blockers (odds ratio, 1.7; p < 0.01), and following decompressive craniectomy (odds ratio, 1.8; p < 0.01) were independently associated with optimal cerebral perfusion pressure curve absence. CONCLUSIONS: This study identified six factors that were independently associated with absence of optimal cerebral perfusion pressure curves.

Observation of Autoregulation Indices During Ventricular CSF Drainage After Aneurysmal Subarachnoid Hemorrhage: A Pilot Study.

BACKGROUND: Cerebral autoregulation is increasingly recognized as a factor that requires evaluation when managing poor grade aneurysmal subarachnoidal hemorrhage (aSAH) patients. In this single center pilot study, we investigated whether intraventricular intracranial pressure (ICP) derived when extraventricular drain (EVD) is open can be used to calculate dynamic autoregulation estimates in ICU aSAH patients. METHODS: Ten patients with the diagnosis of aSAH as confirmed by computed tomography (CT) and CT-angiography were enrolled. ICP was monitored via a transducer connected to the most proximal side exit of the EVD catheter. From at least 30 min periods of brain monitoring before, during, and after temporarily EVD closure, commonly used indexes of dynamic cerebral autoregulation were calculated. RESULTS: Preserved pulsatile ICP signals were seen with open EVD. There were no significant changes in parameters describing cerebral autoregulation between EVD open and closed conditions. Power spectra of ABP and ICP showed no significant changes for the selected frequency ranges. There was a small significant increase in absolute ICP [2.4 (3.8) mmHg, p < 0.001] upon short-term EVD closure. Cerebral spinal reserve capacity (RAP index) worsened significantly by short-term EVD closure. CONCLUSIONS: Due to preserved slow fluctuations in the ICP signal, an open EVD system can be used to calculate dynamic autoregulation indices in aSAH patients requiring intensive care monitoring with the pressure measurement from the most proximal part of drain. If these results are confirmed in larger study, this technique can open the way for investigating the role of autoregulation disturbance in aSAH patients.

Time course and risk factors for myocardial dysfunction after aneurysmal subarachnoid hemorrhage.

BACKGROUND: Myocardial wall motion abnormalities (WMAs) are independent risk factors for a poor outcome in patients with aneurysmal subarachnoid hemorrhage (aSAH). OBJECTIVE: To study the time course of WMAs during the initial phase after aSAH and to investigate which clinical, electrocardiographic, or myocardial serum markers are predictors of early or late development of WMAs. METHODS: In a prospective, multicenter cohort study in patients with aSAH, we performed serial electrocardiography and echocardiography and measured troponin T and N-terminal pro-B-type natriuretic peptide. WMAs present on admission were considered early WMAs; those that developed during the clinical course were considered late WMAs. Using multivariable regression analysis, we calculated odds ratios with corresponding 95% confidence intervals for clinical parameters, electrocardiography, and myocardial serum makers with early or late occurrence of WMAs. RESULTS: We included 301 patients (mean age ± SD, 57 ± 13) years. Multivariable odds ratios for early WMAs were poor clinical condition, 2.7 (95% confidence interval: 1.1-6.8); sinus tachycardia, 5.0 (1.3-19.9); ST-segment depression, 3.7 (1.02-13.1); ST-segment elevation, 16.6 (1.5-178.9); and increased troponin T, 2.8 (1.1-7.3). Multivariable odds ratios (95% confidence intervals) for late development of WMAs were 6.8 (1.6-30) for a myocardial infarct pattern on admission electrocardiography and 3.4 (1.4-8.5) for increased troponin T on admission. CONCLUSION: WMAs may be present on admission or develop during the course of aSAH. Poor neurological condition on admission, sinus tachycardia, ST-segment depression, and ST-segment elevation on admission electrocardiography and increased troponin T are independent predictors of early WMAs; a myocardial infarct pattern on admission ECG and increased troponin T independently predict late WMAs. CLINICAL TRIAL REGISTRATION: NCT00123695.

The course of intracranial pressure in traumatic brain injury: relation with outcome and CT-characteristics.

BACKGROUND: One of the predictive factors of outcome in traumatic brain injury is high intracranial pressure (ICP). Recently, the time course of ICP has been described but few data are available on the relation of these ICP profiles and outcome. The aim of this study is to investigate the relation of the time course of ICP with CT-findings and outcome. METHODS: Retrospective analysis of prospectively collected data of 246 patients with traumatic brain injury admitted to the neurosurgical intensive care unit. RESULTS: Early rise in ICP (within the first 2 days) was present in 32%, an intermediate rise (between days 3 and 5) in 34% and a late rise (after day 5) in 34% of patients. Half of the patients with a normal opening pressure (76%) developed intermediate or late ICP rise profiles. More mass lesions and sub/epidural hematomas were present in the late rise group. Patients with a late ICP rise required significant more intensive treatment (65% vs. 37 and 33%) when compared to the early and intermediate rise groups. In multiple regression analysis both ICP profiles and extracranial hematomas were related to outcome. With late ICP rise more unfavorable outcome (46 vs. 17%, P < 0.001) was seen although one in four patients showed a favorable outcome. CONCLUSION: During ICP monitoring different ICP profiles are present over time. These profiles are related to CT-characteristics and outcome. The importance of early and late monitoring of ICP is underlined.

[Frail elderly women following traffic accident: a specific approach to the trauma care chain]. / Kwetsbare, hoogbejaarde vrouwen na een ernstig verkeersongeval: specifieke aanpak in de traumaketenzorg.

Three octogenarian women suffered severe blunt trauma because of a car crash. The first patient was 81 years old. She had an instable dens fracture, multiple rib fractures, a haematopneumothorax and multiple extremity fractures. The second patient was 82 years old and was diagnosed with a flail chest because of multiple rib fractures, pelvic fractures, and thoracic spine fractures. Before the crash, she already needed help for her daily functioning. The third patient, 84 years old, developed a bradycardia at the site of the crash. In the hospital she was diagnosed with multiple rib fractures, a sternum fracture and a pneumothorax. After appropriate treatment, the second patient had no prospect of recovery and the care was primarily aimed at comfort, until she died. The other two patients remained in a rehabilitation clinic for months after the accident. The necessary approach to first trauma care, ICU care and rehabilitation differs between young and octogenarian patients. These octogenarian female patients constitute a special group of patients because of their frailty. Due to demographic developments and the changes in trauma care, such patients will be treated more often and further in the care chain. During the ICU stay they will require extensive support because of their frailty. The patient's own efforts will also be tremendous. The balance between quality of life adjusted years won and the toll paid by the patient has to be guarded with great care.

Delayed coma in head injury: consider cerebral fat embolism.

OBJECTIVE: To describe a case of a young man with delayed coma after mild head injury, suggestive of cerebral fat embolism (CFE). To underline the value of MR imaging in the differential diagnosis of secondary deterioration in mild head injury. CASE REPORT: A 21-year-old man admitted with mild head injury after a fall with facial fractures and long bone fractures. He was admitted to the intensive care unit and was mechanically ventilated. Weaning was not possible because of desaturations and pulmonary congestion. Low platelet count and anaemia developed. On several time points during his admission cerebral imaging data were obtained. Non-contrast CT on admission was normal while follow-up MRI showed extensive white matter abnormalities. These imaging abnormalities combined with the clinical presentation suggests cerebral fat embolism (CFE) as the most likely cause of secondary deterioration in our patient. CONCLUSIONS: In head injured patients with long bone fractures one should consider cerebral fat embolism. When the classical clinical syndrome is not present, MR imaging is warranted for diagnosis and to exclude other causes of secondary deterioration.

Computer-assisted glucose control in critically ill patients.

OBJECTIVE: Intensive insulin therapy is associated with the risk of hypoglycemia and increased costs of material and personnel. We therefore evaluated the safety and efficiency of a computer-assisted glucose control protocol in a large population of critically ill patients. DESIGN AND SETTING: Observational cohort study in three intensive care units (32 beds) in a 1,300-bed university teaching hospital. PATIENTS: All 2,800 patients admitted to the surgical, neurosurgical, and cardiothoracic units; the study period started at each ICU after implementation of Glucose Regulation for Intensive Care Patients (GRIP), a freely available computer-assisted glucose control protocol. MEASUREMENTS AND RESULTS: We analysed compliance in relation to recommended insulin pump rates and glucose measurement frequency. Patients were on GRIP-ordered pump rates 97% of time. Median measurement time was 5min late (IQR 20min early to 34 min late). Hypoglycemia was uncommon (7% of patients for mild hypoglycemia, < 3.5mmol/l; 0.86% for severe hypoglycemia, < 2.2 mmol/l). Our predefined target range (4.0-7.5 mmol/l) was reached after a median of 5.6 h (IQR 0.2-11.8) and maintained for 89% (70-100%) of the remaining stay at the ICU. The number of measurements needed was 5.9 (4.8-7.3) per patient per day. In-hospital mortality was 10.1%. CONCLUSIONS: Our computer-assisted glucose control protocol provides safe and efficient glucose regulation in routine intensive care practice. A low rate of hypoglycemic episodes was achieved with a considerably lower number of glucose measurements than used in most other schemes.