Cerebral Perfusion Pressure Variability Between Patients and Between Centres.

INTRODUCTION: The aim of this analysis was to investigate to what extent median cerebral perfusion pressure (CPP) differs between severe traumatic brain injury (TBI) patients and between centres, and whether the 2007 change in CPP threshold in the Brain Trauma Foundation guidelines is reflected in patient data collected at several centres over different time periods. METHODS: Data were collected from the Brain-IT database, a multi-centre project between 2003 and 2005, and from a recent project in four centres between 2009 and 2013. For patients nursed with their head up at 30° and with the blood pressure transducer at atrium level, CPP was corrected by 10 mmHg. Median CPP, interquartile ranges and total CPP ranges over the monitoring time were calculated per patient and per centre. RESULTS: Per-centre medians pre-2007 were situated between 50 and 70 mmHg in 6 out of 16 centres, while 10 centres had medians above 70 mmHg and 4 above 80 mmHg. Post-2007, three out of four centres had medians between 60 and 70 mmHg and one above 80 mmHg. One out of two centres with data pre- and post-2007 shifted from a median CPP of 76 mmHg to 60 mmHg, while the other remained at 68-67 mmHg. CONCLUSIONS: CPP data are characterised by a high inter-individual variability, but the data also suggest differences in CPP policies between centres. The 2007 guideline change may have affected policies towards lower CPP in some centres. Deviations from the guidelines occur in the direction of CPP > 70 mmHg.

Visualizing Cerebrovascular Autoregulation Insults and Their Association with Outcome in Adult and Paediatric Traumatic Brain Injury.

OBJECTIVE: The aim of this study is to assess visually the impact of duration and intensity of cerebrovascular autoregulation insults on 6-month neurological outcome in severe traumatic brain injury. MATERIAL AND METHODS: Retrospective analysis of prospectively collected minute-by-minute intracranial pressure (ICP) and mean arterial blood pressure data of 259 adult and 99 paediatric traumatic brain injury (TBI) patients from multiple European centres. The relationship of the 6-month Glasgow Outcome Scale with cerebrovascular autoregulation insults (defined as the low-frequency autoregulation index above a certain threshold during a certain time) was visualized in a colour-coded plot. The analysis was performed separately for autoregulation insults occurring with cerebral perfusion pressure (CPP) below 50 mmHg, with ICP above 25 mmHg and for the subset of adult patients that did not undergo decompressive craniectomy. RESULTS: The colour-coded plots showed a time-intensity-dependent association with outcome for cerebrovascular autoregulation insults in adult and paediatric TBI patients. Insults with a low-frequency autoregulation index above 0.2 were associated with worse outcomes and below -0.6 with better outcomes, with and approximately exponentially decreasing transition curve between the two intensity thresholds. All insults were associated with worse outcomes when CPP was below 50 mmHg or ICP was above 25 mmHg. CONCLUSIONS: The colour-coded plots indicate that cerebrovascular autoregulation is disturbed in a dynamic manner, such that duration and intensity play a role in the determination of a zone associated with better neurological outcome.

Decompressive craniectomy as a second/third-tier intervention in traumatic brain injury: A multicenter observational study.

OBJECTIVES: RESCUEicp studied decompressive craniectomy (DC) applied as third-tier option in severe traumatic brain injury (TBI) patients in a randomized controlled setting and demonstrated a decrease in mortality with similar rates of favorable outcome in the DC group compared to the medical management group. In many centers, DC is being used in combination with other second/third-tier therapies. The aim of the present study is to investigate outcomes from DC in a prospective non-RCT context. METHODS: This is a prospective observational study of 2 patient cohorts: one from the University Hospitals Leuven (2008-2016) and one from the Brain-IT study, a European multicenter database (2003-2005). In thirty-seven patients with refractory elevated intracranial pressure who underwent DC as a second/third-tier intervention, patient, injury and management variables including physiological monitoring data and administration of thiopental were analysed, as well as Extended Glasgow Outcome score (GOSE) at 6 months. RESULTS: In the current cohorts, patients were older than in the surgical RESCUEicp cohort (mean 39.6 vs. 32.3; p < 0.001), had higher Glasgow Motor Score on admission (GMS < 3 in 24.3% vs. 53.0%; p = 0.003) and 37.8% received thiopental (vs. 9.4%; p < 0.001). Other variables were not significantly different. GOSE distribution was: death 24.3%; vegetative 2.7%; lower severe disability 10.8%; upper severe disability 13.5%; lower moderate disability 5.4%; upper moderate disability 2.7%, lower good recovery 35.1%; and upper good recovery 5.4%. The outcome was unfavorable in 51.4% and favorable in 48.6%, as opposed to 72.6% and 27.4% respectively in RESCUEicp (p = 0.02). CONCLUSION: Outcomes in DC patients from two prospective cohorts reflecting everyday practice were better than in RESCUEicp surgical patients. Mortality was similar, but fewer patients remained vegetative or severely disabled and more patients had a good recovery. Although patients were older and injury severity was lower, a potential partial explanation may be in the pragmatic use of DC in combination with other second/third-tier therapies in real-life cohorts. The findings underscore that DC maintains an important role in managing severe TBI.

Femoral neck fractures in patients on Clopidogrel. The effect of delaying surgery and the introduction of the new SIGN guidelines.

INTRODUCTION: Femoral neck fractures are an increasingly common injury in the elderly. Frequently these patients present taking Clopidogrel, an irreversible inhibitor of platelet aggregation. Although this is associated with an increased risk of intra-operative bleeding and also an increased risk of spinal haematoma where regional anaesthesia is employed, the recent SIGN (Scottish Intercollegiate Guidance Network) guidelines recommend that surgery should not be delayed. METHODS: We conducted a retrospective review of consecutive patients admitted with femoral neck fractures between April 2008 and October 2009. Patients on Clopidogrel were identified and data including ASA grade, time to operation, medical co-morbidities, and post-admission complications were recorded. Comparative information from the National Hip Fracture Database was used. RESULTS: 405 patients were included. 27 patients were taking Clopidogrel on admission and they were all ASA 3 or 4. Mean time to theatre was 8 days. Post-admission medical complications occurred in 7 patients (25.9%). A further 4 patients (14.8%) died, 3 of them post-operatively. From the study population a control group of 72 ASA 3 and 4 patients was further studied. The mean time to operation was 2.3 days. Post-admission medical complications occurred in 13 patients (18%) and 8 patients (11%) died post-operatively. The difference in the mortality and morbidity of these two groups was found to be statistically not significant. In 2009 the national mean time to operation was 2.19 days with an associated mortality rate of 8.67%. DISCUSSION AND CONCLUSION: Patients receiving Clopidogrel have complex medical co-morbidities and a higher anaesthetic risk. Delaying operative management might be contributing to the increased rate of mortality and morbidity. In accordance with the SIGN guidelines we recommend early operative intervention in these high risk patients.

The brain monitoring with Information Technology (BrainIT) collaborative network: EC feasibility study results and future direction.

BACKGROUND: The BrainIT group works collaboratively on developing standards for collection and analyses of data from brain-injured patients and to facilitate a more efficient infrastructure for assessing new health care technology with the primary objective of improving patient care. European Community (EC) funding supported meetings over a year to discuss and define a core dataset to be collected from patients with traumatic brain injury using IT-based methods. We now present the results of a subsequent EC-funded study with the aim of testing the feasibility of collecting this core dataset across a number of European sites and discuss the future direction of this research network. METHODS: Over a 3-year period, data collection client- and web-server-based tools were developed and core data (grouped into nine categories) were collected from 200 head-injured patients by local nursing staff in 22 European neuro-intensive care centres. Data were uploaded through the BrainIT website and random samples of received data were selected automatically by computer for validation by data validation staff against primary sources held in each local centre. Validated data were compared with originally transmitted data and percentage error rates calculated by data category. Feasibility was assessed in terms of the proportion of missing data, accuracy of data collected and limitations reported by users of the IT methods. FINDINGS: Thirteen percent of data files required cleaning. Thirty "one-off" demographic and clinical data elements had significant amounts of missing data (>15%). Validation staff conducted 19,461 comparisons between uploaded database data with local data sources and error rates were commonly less than or equal to 6%, the exception being the surgery data class where an unacceptably high error rate of 34% was found. Nearly 10,000 therapies were successfully recorded with start-times but approximately a third had inaccurate or missing "end-times" which limits the analysis of duration of therapy. Over 40,000 events and procedures were recorded but events with long durations (such as transfers) were more likely to have end-times missed. CONCLUSIONS: The BrainIT core dataset is a rich dataset for hypothesis generation and post hoc analyses, provided that studies avoid known limitations in the dataset. Limitations in the current IT-based data collection tools have been identified and have been addressed. In order for multi-centre data collection projects to be viable, the resource intensive validation procedures will require a more automated process and this may include direct electronic access to hospital-based clinical data sources for both validation purposes and for minimising the duplication of data entry. This type of infrastructure may foster and facilitate the remote monitoring of patient management and protocol adherence in future trials of patient management and monitoring.

Development and implementation of a noise reduction intervention programme: a pre- and postaudit of three hospital wards.

AIMS: By developing, implementing and delivering a noise reduction intervention programme, we aimed to attempt to reduce the high noise levels on inpatient wards. BACKGROUND: Sleep is essential for human survival and sleep deprivation is detrimental to health and well being. Exposure to noise has been found to disrupt sleep in hospitalised patients which is to be expected as noise levels have been measured and reported as high. DESIGN: A primarily nursing focused, multi-method approach, involving development of clinical guidelines, ward environment review and a staff noise awareness and education programme, was used to target mainly nursing staff plus other healthcare staff on three wards within one hospital. METHODS: This practice development initiative was carried out in three key phases (1) Preaudit of ward noise levels, (2) The development, implementation and delivery of a noise reduction intervention programme, (3) Postaudit of ward noise levels. RESULTS: Preintervention average peak decibel levels over 24 hours were found to be 96.48 dB(A) and postintervention average peak decibel levels were measured at 77.52 dB(A), representing an overall significant reduction in noise levels (p < 0.001). CONCLUSIONS: This study describes one way to reduce peak noise levels on inpatient hospital wards. RELEVANCE TO CLINICAL PRACTICE: Sleep deprivation is detrimental to patients with acute illness, so any developments to improve patients' sleep are important. Nurses have a key role in leading, developing and implementing changes to reduce peak noise levels on inpatient wards in hospitals. This nurse-led practice development programme has demonstrated how improvements can be achieved by significantly reducing peak noise levels using simple multi-method change strategies.

The brain monitoring with Information Technology (BrainIT) collaborative network: data validation results.

BACKGROUND: The BrainIT group works collaboratively on developing standards for collection and analyses of data from brain injured patients towards providing a more efficient infrastructure for assessing new health technology. MATERIALS AND METHODS: Over a 2 year period, core dataset data (grouped by nine categories) were collected from 200 head-injured patients by local nursing staff. Data were uploaded by the BrainIT web and random samples of received data were selected automatically by computer for validation by data validation (DV) research nurse staff against gold standard sources held in the local centre. Validated data was compared with original data sent and percentage error rates calculated by data category. FINDINGS: Comparisons, 19,461, were made in proportion to the size of the data received with the largest number checked in laboratory data (5,667) and the least in the surgery data (567). Error rates were generally less than or equal to 6%, the exception being the surgery data class where an unacceptably high error rate of 34% was found. CONCLUSIONS: The BrainIT core dataset (with the exception of the surgery classification) is feasible and accurate to collect. The surgery classification needs to be revised.

BrainIT collaborative network: analyses from a high time-resolution dataset of head injured patients.

BACKGROUND: The BrainIT project was conceived in 1997 and has grown into an international collaboration with the purpose of gathering high time resolution data from head injured patients utilising standardised methodologies. MATERIALS AND METHODS: From 1998, 22 participating neuroscience centres collected three main types of information: demographic, physiological data and clinical treatment information. A data collection solution was provided for each centre dependent on their existing facilities and data were collected for the duration of monitoring as defined by the routine care in each centre. On completion of ICP monitoring all personal information was removed and then transferred to Glasgow via the internet where it was converted into a standard format and entered into a central database. Outcome was measured using the extended Glasgow Outcome Score using an interview questionnaire. FINDINGS: Data has been obtained from a total of 349 patients (277 male and 72 female) The age of these patients ranged from 1 to 87 years (median 31); 145 had been involved in a traffic accident and 32 were pedestrians; 78 had suffered a fall; 24 were assaulted and the remaining 70 of other causes. A large amount of physiological data was collected (e.g. BP 2,531 days, ICP 2,212 days in total). This dataset has provided the opportunity to perform unique analysis and these include the statistical features of blood pressure, diurnal variations in ICP, optimal sampling rate determination and a comparison of summary measures of secondary insults. CONCLUSIONS: This challenging collaboration has brought together a large number of centres and developed a successful clinical research network focussed on improving the treatment of head injured patients. It has successfully collected a vast quantity of high quality data that provides a rich source for analysis and hypothesis testing.

Blood pressure in head-injured patients.

OBJECTIVE: To determine the statistical characteristics of blood pressure (BP) readings from a large number of head-injured patients. METHODS: The BrainIT group has collected high time-resolution physiological and clinical data from head-injured patients who require intracranial pressure (ICP) monitoring. The statistical features of this dataset of BP measurements with time resolution of 1 min from 200 patients is examined. The distributions of BP measurements and their relationship with simultaneous ICP measurements are described. RESULTS: The distributions of mean, systolic and diastolic readings are close to normal with modest skewing towards higher values. There is a trend towards an increase in blood pressure with advancing age, but this is not significant. Simultaneous blood pressure and ICP values suggest a triphasic relationship with a BP rising at 0.28 mm Hg/mm Hg of ICP, for ICP up to 32 mm Hg, and 0.9 mm Hg/mm Hg of ICP for ICP from 33 to 55 mm Hg, and falling sharply with rising ICP for ICP >55 mm Hg. CONCLUSIONS: Patients with head injury appear to have a near normal distribution of blood pressure readings that are skewed towards higher values. The relationship between BP and ICP may be triphasic.

Assessment of cerebrospinal fluid outflow resistance.

The brain and the spinal cord are contained in a cavity and are surrounded by cerebrospinal fluid (CSF), which provides physical support for the brain and a cushion against external pressure. Hydrocephalus is a disease, associated with disturbances in the CSF dynamics, which can be surgically treated by inserting a shunt or third ventriculostomy. This review describes the physiological background, modeling and mathematics, and the investigational methods for determining the CSF dynamic properties, with specific focus on the CSF outflow resistance, R out. A model of the cerebrospinal fluid dynamic system, with a pressure-independent R out, a pressure-dependent compliance and a constant formation rate of CSF is widely accepted. Using mathematical expressions calculated from the model, along with active infusion of artificial CSF and observation of corresponding change in ICP allows measurements of CSF dynamics. Distinction between normal pressure hydrocephalus and differential diagnoses, prediction of clinical response to shunting and the possibility of assessment of shunt function in vivo are the three most important applications of infusion studies in clinical practice.

Cerebral Perfusion Pressure Insults and Associations with Outcome in Adult Traumatic Brain Injury.

The definition of cerebral perfusion pressure (CPP) secondary insults in severe traumatic brain injury remains unclear. The purpose of the present study is to visualize the association of intensity and duration of episodes below or above CPP thresholds and outcome. The analysis was based on prospectively collected minute-by-minute intracranial pressure (ICP) and blood pressure data and outcome from 259 adult patients. The relationship of episodes of CPP below or above a certain threshold for certain duration with the 6-month Glasgow Outcome Score was visualized separately for episodes of active or deficient autoregulation (AR). In adults ≤65 years, an almost exponential transition curve separates the episodes of CPP associated with better outcomes from the episodes of low CPP associated with worse outcomes, indicating that lower CPP could only be tolerated for a brief time. Analysis of episodes of high CPP again showed a time-intensity dependent association with outcome. When combining the two plots, a safe CPP zone between 60 and 70 mm Hg could be delineated-however, only for AR active insults. The AR status predominantly affected the transition curve for insults of low CPP. Episodes with ICP >25 mm Hg were associated with poor outcome regardless of CPP. In the present study, the CPP pressure-time burden associated with poor outcome was visualized. A safe zone between 60 and 70 mm Hg could be identified for adults ≤65 years, provided AR was active and ICP was ≤25 mm Hg. Deficient AR reduces the tolerability for low CPP.

Differences in subsidence rate between alternative designs of a commonly used uncemented femoral stem.

INTRODUCTION: Measurement of early subsidence of uncemented femoral stems can be used to evaluate the likelihood of long term stem component loosening and therefore clinical failure. Our aim was to evaluate the factors associated with subsidence in collared and uncollared versions of the Corail femoral stem. METHODS: 121 hips in 113 consecutive patients were studied, operated on by two surgeons in our hospital differing in their choice of Corail stem. This gave two groups of patients with 66 hips having collared stems and 55 hips having uncollared. We recorded patients' age, sex, ASA grade and BMI. Radiographs post-operatively at day 1, 6 weeks and 1 year were evaluated measuring subsidence, angulation, signs of stability and fixation, and canal fill ratio at the metaphysis and diaphysisafter correcting for magnification errors by calibration using femoral head size. RESULTS: Clinically significant subsidence (>3 mm) occurred in 7.6% of collared and 10.9% of uncollared stems, all within 6-8 weeks, but did not reach statistical significance (p = 0.345). Revision for symptomatic loosening was required in 1 patient in each group (1.5% collared versus 1.8% uncollared). DISCUSSION: Early subsidence of Corail femoral stem should alert surgeons to closer patient follow-up as the rate of early revision is 18% in stems with >3 mm of subsidence. However, the presence of a collar does not seem to be protective.

The TONK score: a tool for assessing quality in trauma and orthopaedic note-keeping.

INTRODUCTION: Medical case notes are the only lasting interpretation of a patient-physician interaction and are important for good quality patient care. Accurate, legible and contemporaneous note-keeping is important however it can be substandard. This can lead to errors in handover of patients and to medicolegal vulnerability. We present a comprehensive auditing tool for Trauma & Orthopaedics medical case notes and our experience in using it over the last 12 months. PATIENTS AND METHODS: The TONK score was developed from a pre-existing system with some additions for Trauma & Orthopaedic case notes, with the incorporation of a legibility scoring system. An initial audit was carried out evaluating the case notes for each team against the TONK score. In order to evaluate the reproducibility of this score, we employed the Cohen's Kappa coefficient and noted substantial agreement. The individual team scores were analysed and the audit cycle completed four months later with the provision of feedback. RESULTS: Our first audit revealed a mean of 81 with a range from 70 to 90. Subsequent audits over the next two quarters revealed mean scores in excess of 90. Significant improvement has been noted in all areas of documentation and it has been decided to conduct this audit every six months in our department. CONCLUSIONS: The TONK score is an easy, quick and reproducible tool, which aims to eliminate the weaknesses in Trauma & Orthopaedic medical note-keeping. It emphasises the medicolegal importance of accurate medical note-keeping to doctors at all levels of training.

Surgical Trial In Traumatic intraCerebral Haemorrhage (STITCH): a randomised controlled trial of Early Surgery compared with Initial Conservative Treatment.

BACKGROUND: While it is accepted practice to remove extradural (EDH) and subdural haematomas (SDH) following traumatic brain injury, the role of surgery in parenchymal traumatic intracerebral haemorrhage (TICH) is controversial. There is no evidence to support Early Surgery in this condition. OBJECTIVES: There have been a number of trials investigating surgery for spontaneous intracerebral haemorrhage but none for TICH. This study aimed to establish whether or not a policy of Early Surgery for TICH improves outcome compared with a policy of Initial Conservative Treatment. DESIGN: This was an international multicentre pragmatic parallel group trial. Patients were randomised via an independent telephone/web-based randomisation service. SETTING: Neurosurgical units in 59 hospitals in 20 countries registered to take part in the study. PARTICIPANTS: The study planned to recruit 840 adult patients. Patients had to be within 48 hours of head injury with no more than two intracerebral haematomas greater than 10 ml. They did not have a SDH or EDH that required evacuation or any severe comorbidity that would mean they could not achieve a favourable outcome if they made a complete recovery from their head injury. INTERVENTIONS: Patients were randomised to Early Surgery within 12 hours or to Initial Conservative Treatment with delayed evacuation if it became clinically appropriate. MAIN OUTCOME MEASURES: The Extended Glasgow Outcome Scale (GOSE) was measured at 6 months via a postal questionnaire. The primary outcome was the traditional dichotomised split into favourable outcome (good recovery or moderate disability) and unfavourable outcome (severe disability, vegetative, dead). Secondary outcomes included mortality and an ordinal assessment of Glasgow Outcome Scale and Rankin Scale. RESULTS: Patient recruitment began in December 2009 but was halted by the funding body because of low UK recruitment in September 2012. In total, 170 patients were randomised from 31 centres in 13 countries: 83 to Early Surgery and 87 to Initial Conservative Treatment. Six-month outcomes were obtained for 99% of 168 eligible patients (82 Early Surgery and 85 Initial Conservative Treatment patients). Patients in the Early Surgery group were 10.5% more likely to have a favourable outcome (absolute benefit), but this difference did not quite reach statistical significance because of the reduced sample size. Fifty-two (63%) had a favourable outcome with Early Surgery, compared with 45 (53%) with Initial Conservative Treatment [odds ratio 0.65; 95% confidence interval (CI) 0.35 to 1.21; p = 0.17]. Mortality was significantly higher in the Initial Conservative Treatment group (33% vs. 15%; absolute difference 18.3%; 95% CI 5.7% to 30.9%; p = 0.006). The Rankin Scale and GOSE were significantly improved with Early Surgery using a trend analysis (p = 0.047 and p = 0.043 respectively). CONCLUSIONS: This is the first ever trial of surgery for TICH and indicates that Early Surgery may be a valuable tool in the treatment of TICH, especially if the Glasgow Coma Score is between 9 and 12, as was also found in Surgical Trial In spontaneous intraCerebral Haemorrhage (STICH) and Surgical Trial In spontaneous lobar intraCerebral Haemorrhage (STICH II). Further research is clearly warranted. TRIAL REGISTRATION: Current Controlled Trials ISRCTN 19321911. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 19, No. 70. See the NIHR Journals Library website for further project information.

Early Surgery versus Initial Conservative Treatment in Patients with Traumatic Intracerebral Hemorrhage (STITCH[Trauma]): The First Randomized Trial.

Intraparenchymal hemorrhages occur in a proportion of severe traumatic brain injury TBI patients, but the role of surgery in their treatment is unclear. This international multi-center, patient-randomized, parallel-group trial compared early surgery (hematoma evacuation within 12 h of randomization) with initial conservative treatment (subsequent evacuation allowed if deemed necessary). Patients were randomized using an independent randomization service within 48 h of TBI. Patients were eligible if they had no more than two intraparenchymal hemorrhages of 10 mL or more and did not have an extradural or subdural hematoma that required surgery. The primary outcome measure was the traditional dichotomous split of the Glasgow Outcome Scale obtained by postal questionnaires sent directly to patients at 6 months. The trial was halted early by the UK funding agency (NIHR HTA) for failure to recruit sufficient patients from the UK (trial registration: ISRCTN19321911). A total of 170 patients were randomized from 31 of 59 registered centers worldwide. Of 82 patients randomized to early surgery with complete follow-up, 30 (37%) had an unfavorable outcome. Of 85 patients randomized to initial conservative treatment with complete follow-up, 40 (47%) had an unfavorable outcome (odds ratio, 0.65; 95% confidence interval, CI 0.35, 1.21; p=0.17), with an absolute benefit of 10.5% (CI, -4.4-25.3%). There were significantly more deaths in the first 6 months in the initial conservative treatment group (33% vs. 15%; p=0.006). The 10.5% absolute benefit with early surgery was consistent with the initial power calculation. However, with the low sample size resulting from the premature termination, we cannot exclude the possibility that this could be a chance finding. A further trial is required urgently to assess whether this encouraging signal can be confirmed.

Visualizing the pressure and time burden of intracranial hypertension in adult and paediatric traumatic brain injury.

PURPOSE: To assess the impact of the duration and intensity of episodes of increased intracranial pressure on 6-month neurological outcome in adult and paediatric traumatic brain injury. METHODS: Analysis of prospectively collected minute-by-minute intracranial pressure and mean arterial blood pressure data of 261 adult and 99 paediatric traumatic brain injury patients from multiple European centres. The relationship of episodes of elevated intracranial pressure (defined as a pressure above a certain threshold during a certain time) with 6-month Glasgow Outcome Scale was visualized in a colour-coded plot. RESULTS: The colour-coded plot illustrates the intuitive concept that episodes of higher intracranial pressure can only be tolerated for shorter durations: the curve that delineates the duration and intensity of those intracranial pressure episodes associated with worse outcome is an approximately exponential decay curve. In children, the curve resembles that of adults, but the delineation between episodes associated with worse outcome occurs at lower intracranial pressure thresholds. Intracranial pressures above 20 mmHg lasting longer than 37 min in adults, and longer than 8 min in children, are associated with worse outcomes. In a multivariate model, together with known baseline risk factors for outcome in severe traumatic brain injury, the cumulative intracranial pressure-time burden is independently associated with mortality. When cerebrovascular autoregulation, assessed with the low-frequency autoregulation index, is impaired, the ability to tolerate elevated intracranial pressures is reduced. When the cerebral perfusion pressure is below 50 mmHg, all intracranial pressure insults, regardless of duration, are associated with worse outcome. CONCLUSIONS: The intracranial pressure-time burden associated with worse outcome is visualised in a colour-coded plot. In children, secondary injury occurs at lower intracranial pressure thresholds as compared to adults. Impaired cerebrovascular autoregulation reduces the ability to tolerate intracranial pressure insults. Thus, 50 mmHg might be the lower acceptable threshold for cerebral perfusion pressure.

What is the optimal cerebral perfusion pressure in children suffering from traumatic coma?

Head injury is a major cause of death and disability in children. Despite advances in resuscitation, emergency care, intensive care monitoring, and clinical practices, there are few data demonstrating the predictive value of certain physiological variables regarding outcome in this patient population. Mean arterial blood pressure (MABP), intracranial pressure (ICP), and cerebral perfusion pressure (CPP = MABP - ICP) are routinely monitored in patients in many neurological intensive care units throughout the world, but there is little evidence indicating that advances in care have been matched with corresponding improvements in outcome. Nonetheless, there is evidence that hypotension immediately following head injury is predictive of early death, and many patients with these features die with clinical signs of brain herniation caused by intracranial hypertension. Furthermore, available data indicate that a minimal and a mean CPP measured during intensive care are good predictors of outcome in survivors, but a target threshold to improve outcome has yet to be defined. Some medical management strategies can have detrimental effects, and there is now a good case for undertaking a controlled trial of immediate or delayed craniectomy. Independent outcome in children following severe head injury is associated with higher levels of CPP. The ability to tolerate different levels of CPP may be related to age, and therefore any such surgical trial would need a carefully defined protocol so that the potential benefit of such a treatment is maximized.

Predicting clinical ischaemia during awake carotid endarterectomy: use of the SJVO2 probe as a guide to selective shunting.

Stroke is a major cause of disability within the western world. About 20% of strokes are a consequence of atheromatous narrowing of the origin of the internal carotid artery. Carotid endarterectomy has been shown to be an effective treatment for those with symptomatic and severe stenosis, provided the risk of death and peri-operative stroke is less than 7%. The aim of this study was to investigate the clinical value of jugular venous oxygen saturation (SJVO2) monitoring in identifying patients who develop cerebral ischaemia whilst undergoing an awake carotid endarterectomy by comparison with a simple neurological assessment. Each patient underwent a standard awake carotid endarterectomy. Peri-operatively a SJVO2 catheter was inserted, and the jugular oxygen saturation was correlated with the presence or absence of cerebral ischaemia. Data from 34 patients were analysed using time-series plots and by calculating a receiver operator characteristic (ROC) curve. The optimal sensitivity and specificity for this technique were found to be 1.0 and 0.8, respectively, when a 25% change in SJVO2 was used as a threshold. Although a small observational study, we have shown that percentage change in SJVO2 correlates well with the development of clinically apparent cerebral ischaemia. This technique may improve the safety of carotid endarterectomy under general anaesthesia when used with other more established monitoring methods.

A multi-parameter system for use in neonatal resuscitation research and training.

Training staff in the resuscitation of neonates is an essential skill; resuscitation efficacy is difficult to quantify but critical to infant survival. Objective assessments of the efficacy of training methods, resuscitation techniques and devices have used concurrent measurements of air flow and air pressure in commercially available manikins. This system also simultaneously measures the force transmitted through the manikin head during simulated resuscitation, as applying excessive force may be deleterious to newborn infants. The overall accuracy of the force plate over the range 0-5 kg was 0.5%; the output was linear; the frequency response sufficiently high and there was no evidence of hysteresis. This system enables comparison of staff groups, resuscitation techniques and devices in an accurate and reproducible manner. Its use could improve training by offering a means of objective performance feedback through a range of parameters. Evaluation of clinical practice may also result in direct patient benefit.

Surgical trial in traumatic intracerebral hemorrhage (STITCH(Trauma)): study protocol for a randomized controlled trial.

BACKGROUND: Intracranial hemorrhage occurs in over 60% of severe head injuries in one of three types: extradural (EDH); subdural (SDH); and intraparenchymal (TICH). Prompt surgical removal of significant SDH and EDH is established and widely accepted. However, TICH is more common and is found in more than 40% of severe head injuries. It is associated with a worse outcome but the role for surgical removal remains undefined. Surgical practice in the treatment of TICHs differs widely around the world. The aim of early surgery in TICH removal is to prevent secondary brain injury. There have been trials of surgery for spontaneous ICH (including the STICH II trial), but none so far of surgery for TICH. METHODS/DESIGN: The UK National Institutes of Health Research has funded STITCH(Trauma) to determine whether a policy of early surgery in patients with TICH improves outcome compared to a policy of initial conservative treatment. It will include a health economics component and carry out a subgroup analysis of patients undergoing invasive monitoring. This is an international multicenter pragmatic randomized controlled trial.Patients are eligible if: they are within 48 h of injury; they have evidence of TICH on CT scan with a confluent volume of attenuation significantly raised above that of the background white and grey matter that has a total volume >10 mL; and their treating neurosurgeon is in equipoise.Patients will be ineligible if they have: a significant surface hematoma (EDH or SDH) requiring surgery; a hemorrhage/contusion located in the cerebellum; three or more separate hematomas fulfilling inclusion criteria; or severe pre-existing physical or mental disability or severe co-morbidity which would lead to poor outcome even if the patient made a full recovery from the head injury.Patients will be randomized via an independent service. Patients randomized to surgery receive surgery within 12 h. Both groups will be monitored according to standard neurosurgical practice. All patients have a CT scan at 5 days (+/-2 days) to assess changes in hematoma size. Follow-up is by postal questionnaire at 6 and 12 months. The recruitment target is 840 patients. TRIAL REGISTRATION: Current Controlled Trials ISRCTN19321911.