Background: SARS-CoV-2 displays high affinity for ACE2 receptors, expressed on type 2 alveolar cells. These cells produce pulmonary surfactant - a crucial thin layer of surface-active lipid rich fluid - fundamental for proper gas exchange. Aims and objectives: To investigate changes in surfactant lipid composition and the relationship to prolonged symptoms of post covid-19 among patients treated in intensive care unit for covid-19 infection. Methods: Patients (n=43, 17 female, aged 44-80 years) treated in an intensive care unit with covid-19 infection in average six months prior to enrollment were recruited. Particles in exhaled air were collected with PExA-instrument (PExA AB) and we also conducted body plethysmograph and diffusion capacity of the lungs for carbon monoxide. Twenty-two healthy, non-infected, age- and gender-matched controls were also enrolled. Lipids were analysed using liquid chromatography with a triple quadrupole mass spectrometer. Statistical analyses were performed with Qlucore. Results: Preliminary results suggest a significant change in the composition of surfactant lipids. Analysis show significant reductions of all measured phosphatidyl-glycerols (PG, n=14) an increase of all measured phosphatidyl-inositols (PI, n=4), e.g. PG 18:1_18:1 22 % lower (p<0.001, q=0.04) and PI:16:0:18:1 67% higher (p<0.001, q=0.0003) among the post-covid patients compared to controls. Conclusion: Our findings suggest that surfactant composition is altered also in the recovery phase after covid-19 infection which could be a key component in the post-covid syndrome with lingering effects on the respiratory system.

BackgroundPatients with aneurysmal subarachnoid hemorrhage (aSAH) have poor outcome. Studies on outcome beyond 1year post-aSAH are few, and late recovery is poorly investigated, initiating this prospective outcome study on patients 12-15years after an aSAH. We hypothesized to find; functional improvement>1year post-ictus; increased long-term mortality in aSAH patients vs matched controls, and finally to present; predictors of long-term favorable outcome (GOS 4-5). MethodsWe prospectively investigated patients, admitted 2000-2003 to the Sahlgrenska University Hospital, 1year post-ictus using Glasgow Outcome Scale (GOS). The patients were revalidated 12-15years post-aSAH by structured-telephone interviews (GOS), followed by statistical analysis. ResultsA total of 158 patients were included, (women n=114, men n=44), with a mean age of 55years at aSAH. Patients treated with surgical clipping had lower mortality. At the follow-up 12-15years post-aSAH, all 103 survivors (65.2%) were categorized as having; good recovery (39.9%), moderate disability (15.2%), or severe disability (10.1%). Within the patient cohort, 23.6% improved GOS over time. Fifty-five patients died, median at 4years post-ictus. aSAH patients had 3.5 times increased mortality 12-15years post-ictus vs matched controls (P<.0001). Patients with favorable outcome at 1year (67.3%, n=101) had similar survival probability as control patients. Prognostic indicators of long-term favorable outcome were low age and high GOS at 1-year follow-up, (AUCROC, 0.79). ConclusionsIndividual functional improvement was found >1year post-ictus. Patients with favorable outcome at 1year had similar long-term life expectancy as the general population. Indicators of long-term favorable prognosis were low age at ictus and high GOS at 1-year follow-up.

BACKGROUND:Severe traumatic brain injury (sTBI) can be divided into primary and secondary injuries. Intensive care protocols focus on preventing secondary injuries. This prospective cohort study was initiated to investigate outcome, including mortality, in patients treated according to the Lund Concept after a sTBI covering 10-15 years post-trauma.METHODS:Patients were included during 2000-2004 when admitted to the neurointensive care unit, Sahlgrenska University Hospital. Inclusion criteria were: Glasgow coma scale score of ≤8, need for artificial ventilation and intracranial monitoring. Glasgow Outcome Scale (GOS) was used to evaluate outcome both at 1-year and 10-15 years post-trauma.RESULTS:Ninety-five patients, (27 female and 68 male), were initially included. Both improvement and deterioration were noted between 1- and 10-15 years post-injury. Mortality rate (34/95) was higher in the studied population vs. a matched Swedish population, (Standard mortality rate (SMR) 9.5; P < 0.0001). When dividing the cohort into Good (GOS 4-5) and Poor (GOS 2-3) outcome at 1-year, only patients with Poor outcome had a higher mortality rate than the matched population (SMR 7.3; P < 0.0001). Further, good outcome (high GOS) at 1-year was associated with high GOS 10-15 years post-trauma (P < 0.0001). Finally, a majority of patients demonstrated symptoms of mental fatigue.CONCLUSION:This indicates that patients with severe traumatic brain injury with Good outcome at 1-year have similar survival probability as a matched Swedish population and that high Glasgow outcome scale at 1-year is related to good long-term outcome. Our results further emphasise the advantage of the Lund concept.

BackgroundThis study aimed to examine prospectively whether the inflammatory marker C‐reactive protein (CRP) increases in patients with aneurysmal subarachnoid haemorrhage (aSAH) treated by endovascular coiling and investigate whether CRP could be used as prognostic factor for long‐term neurological outcome.MethodsThis single‐hospital study comprised 98 consecutive patients with confirmed aSAH treated by endovascular coiling. Admission status was classified according to the World Federation of Neurosurgical Societies (WFNS) Scale and initial cerebral computed tomography according to Fisher scale. CRP was analysed on days 0, 1, 2, 3, 4, 6 and 8 after the initial bleed. A neurological follow up was performed 1 year later according to the Extended Glasgow Outcome Scale (GOSE) for overall outcome and National Institute of Health Stroke Scale (NIHSS) for focal deficit.ResultsCRP values increased from normal to peak at 53 mg/l at day 3–4 and then declined, without normalising, at day 8. Patients with a higher increase in CRP had a poorer neurological outcome after 1 year. CRP during the first week had a stronger correlation to outcome (r = 0.417) and NIHSS (r = 0.449) than initial clinical status (WFNS; r = 0.280 and 0.274) and radiology (Fisher scale; r = 0.137 and 0.158). CRP increase indicated a risk of poor outcome (GOSE) (P < 0.001) and permanent loss of neurological function (NIHSS) (P < 0.001). Logistic regression analysis suggested that elevated CRP already on day 2 is an independent prognostic marker for outcome.ConclusionEarly CRP values can perhaps be used as a prognostic factor for long‐term neurological outcome prediction after endovascular treatment of aSAH.

Background: Patients admitted to intensive care units (ICU) due to severe critical illness often develop severe muscle wasting and impaired muscle function. This can lead to delayed recovery, extended hospital stay, increased morbidity and negatively affect the patient's quality of life after hospital discharge.

Aneurysmal subarachnoid haemorrhage (aSAH) is associated with high morbidity and mortality despite novel treatments. Genetic variability may explain outcome differences. Apolipoprotein E (ApoE) is a glycoprotein with a major role in brain lipoprotein metabolism. It has three isoforms encoded by distinct alleles: APOEε2, APOEε3 and APOEε4. The APOEε4 allele is associated with Alzheimer's disease and worse outcome after traumatic brain injury and ischaemic stroke. This prospective blinded study explored the influence of the APOEε4 polymorphism on the risk of aSAH, risk of cerebral vasospasm (CVS) and 1-year neurological outcome.The APOΕε4 polymorphism was analysed in 147 patients with aSAH. Allele and genotype frequencies were compared to those found in a gender- and area-matched control group of healthy individuals (n = 211). Early CVS was identified and treated according to neurointensive care unit (NICU) guidelines. Neurological deficit(s) at admittance and at 1-year follow-up visit was recorded. Neurological outcome was assessed by the National Institute of Health Stroke Scale, Barthel Index and the Extended Glasgow Outcome Scale.APOEε4 and non-APOEε4 allele frequencies were similar in aSAH patients and healthy individuals. The presence of APOEε4 was not associated with the development of early CVS. We could not find an influence of the APOE polymorphism on 1-year neurological outcome between groups. Subgroup analyses of patients treated with surgical clipping vs endovascular coiling did not reveal any associations.The APOEε4 polymorphism has no major influence on risk of aSAH, the occurrence of CVS or long-term neurological outcome after aSAH.

12 – Fig. 1. Typical examples of DWI and Tmax map of lateral medullary infarction (LMI) with progression to hemimedullary infarction (HMI) (A–D) and without progression (E–G); DWI of LMI with progression showed acute lateral medullary infarction in the right upper medulla (A, solid arrow) followed by additional medial medullaru infarction (B, open arrow). Tmax map demonstrated severe perfusion delay of the PICA territory in this patient (C, D). DWI of LMI without progression revealed acute lateral medullary infarction in the left middle medulla (arrow head) and small scattered lesions in the PICA territory (E). Tmax map of this patient showed mild perfusion delay in the PICA territory (F, G). most of the cases. The PWI of the brain MRI showed ipsilateral PICA territory perfusion delay in all of the 7 HMI(100%), 3 of the 17 LMI(17.6%) and 2 of the 6 MMI(33.3%) (p<0.001). Tmax perfusion lesion maps of HMI showed more severe hypoperfused area in the ipsilateral PICA territory compared with LMI and MMI (Fig. 1, below). The vascular study revealed the significant stenosis or occlusion of ipsilateral vertebral artery; 6 of the 7 HMI(85.7%), 11 of the 22 LMI(50.0%) and 6 of the 8 MMI(75.0%). The main stroke mechanism of HMS was vertebral artery dissection. Conclusion: The progression of the medullary infarction (mainly in HMI) was common in this series; considering total of 7 HMI, 5 initially manifested as LMI or MMI. Our data illustrate that HMI often accompany with PICA territory perfusion delay which is more severe than those with LMI and MMI. These findings suggest PWI may predict progression of LMI or MMI to HMI. Likewise anterior circulation infarction, PWI can guide treatment approach, especially in medullary infarction.

Background: Traumatic brain injury (TBI) is one of the most common causes of death and dismal outcome among children and young adults. The morbidity and mortality differ but more aggressive monitoring and more designated neuro intensive care units have improved the results. Studies have demonstrated a connection between apolipoprotein E (APOE) genotype and outcome after TBI, but few are prospective and none is from northern Europe. APOE has three alleles: ɛ2, ɛ3 and ɛ4.Methods: A total of 96 patients with Glasgow coma score (GCS) ≤8 were prospectively and consecutively included. APOE genotypes were all analyzed at the same laboratory from blood samples by polymerase chain reaction‐restriction fragment length polymorphism.Results: All patients were assessed at 1 year with Glasgow outcome scale extended (GOSE), National Institute of Health Stroke Scale (NIHSS) and the Barthel daily living index. The genotype was available in all patients. Twenty‐six patients expressed APOE ɛ4 while 70 patients did not. Outcome demonstrated that patients with APOE ɛ4 had worse outcome vs. those lacking this allele. When subdividing patients into gender, males with APOE ɛ4 did worse, a difference not detected among female patients.Conclusions: APOE ɛ4 correlated to worse outcome in TBI patients. We also found that males with APOE ɛ4 had poor outcome while females did not. Thus, the results indicate that genetic polymorphism may influence outcome after TBI.

Objectives. S100B is an established marker of brain damage. Used in the context as a biochemical marker, S100B denotes a measurement of all S100 proteins, including at least one S100B monomer, i.e. the sum of the two dimers S100A1B and S100BB. Almost all published studies are based on this "sum concentration". However, the brain specificity of S100B has been questioned and increased serum levels have also been reported after trauma without head injury. Since the S100B monomer dominates in the brain, we hypothesised that the S100BB dimer should be better related to outcome after severe traumatic brain injury than S100A1B or the "sum concentration".Methods. Daily serum samples were collected from 59 patients with severe traumatic brain injury. Three different ELISA methods were used for measurements of S100B, S100A1B and S100BB respectively. Outcome was assessed after one year and categorised according to the Glasgow Outcome Scale.Results. Serum levels of S100B, S100A1B and S100BB followed the same temporal course, with early maximum and rapidly decreasing values over the first days after the trauma. Maximum serum concentrations of each of the parameters were increased in the patient group with an unfavourable outcome compared with those with a favourable outcome (p = 0.01, 0.006 and 0.004, respectively).Conclusion. Both S100A1B and S100BB were related to outcome after severe traumatic brain injury. Even though this study is small, it seems unlikely that separate analyses of the dimers are of any advantage compared with measuring S100B alone.

Background: Prone position has been used for several years to treat acute lung insufficiency, but in previous studies patients with unstable intracranial pressure (ICP) are mostly excluded. The aim of this study was to investigate if prone position is a safe and useful treatment in patients with reduced intracranial compliance.Methods: A consecutive, prospective pilot study of 11 patients admitted to the neuro intensive care unit (NICU) due to traumatic brain injury or intracerebral haemorrhage. ICP, cerebral perfusion pressure (CPP), heart rate (HR), mean arterial blood pressure (MABP), arterial partial pressure of oxygen (PaO2), arterial partial pressure of carbon dioxide (PaCO2), arterial oxygen saturation (SaO(2)) and respiratory system compliance were measured before, three times during and two times after the patients were placed in the prone position.Results: No significant changes were demonstrated in ICP, CPP or MABP. PaO2 and SaO(2) were significantly increased in the prone position. HR was significantly increased in the prone position and after 10 min in the supine post-prone position and the respiratory system compliance was increased after 1 h in the supine post-prone position.Conclusion: Turning NICU patients from the supine to the prone position did not influence ICP, CPP or MABP, but significantly improved patient PaO2, SaO(2) and respiratory system compliance.

Objective: We investigated if tau, microtubular binding protein, in serum and ventricular CSF (vCSF) in patients with severe traumatic brain injury (TBI) during the initial posttraumatic days correlated to 1-year outcome. Methods: Patients with severe TBI (n = 39, Glasgow Coma Scale score <= 8) were included. We measured serum and vCSF total tau on days 0 to 14, using ELISA. vCSF total tau correlated to 1-year Extended Glasgow Outcome Scale (GOSE), the NIH Stroke Scale (NIHSS) neurologic status, and the Bartel Daily Living Index. Patients (n = 20) with normal pressure hydrocephalus (NPH) served as reference. Results: Higher levels of tau were found in TBI patients vs patients with NPH. A correlation was found between initial vCSF total tau and GOSE levels (R = 0.42, p < 0.001) but not between vCSF total tau and NIHSS or Bartel scores at 1 year. A vCSF total tau level of > 2,126 pg/mL on days 2 to 3 discriminated between dead and alive ( sensitivity of 100% and a specificity of 81%). A vCSF total tau level of > 702 pg/mL on days 2 to 3 discriminated between bad ( GOSE 1 to 4) and good ( GOSE 5 to 8) outcome ( sensitivity of 83% and a specificity of 69%). Patients with GOSE 1 (dead) had higher vCSF total tau levels on days 2 to 3 (p < 0.001) vs both surviving patients (GOSE 2 to 8) and those with NPH. Total tau was not detected in serum throughout the study. Conclusion: The increase in ventricular CSF (vCSF) total tau probably reflects axonal damage, known to be a central pathologic mechanism in traumatic brain injury ( TBI). These results suggest that vCSF total tau may be an important early biochemical neuromarker for predicting long-term outcome in patients with a severe TBI.

Aneurysmal subarachnoid hemorrhage (aSAH) is a devastating event. Following the bleeding, a number of pathophysiological changes and clinical factors determine outcome. Not surprisingly, attempts to predict outcome based on a single factor have failed. The neurological status graded at admission to hospital and distributions of the blood on CT are the strongest predictors. There is evidence that cerebrospinal fluid (CSF) proteins may serve as markers of the extent of brain damage. The present study is focused on the light unit of neurofilament protein (NFL), previously not evaluated in aSAH. Lumbar puncture (LP), neurological grading according to World Federation of Neurological Surgeons (WFNS) and neurological examination according to the National Institute of Health Stroke Scale (NIHSS) were performed in 48 consecutive patients with aSAH 10–14 days after the hemorrhage. CSF–NFL concentrations were analyzed using an ELISA. Outcome was assessed after 1 year and categorised according to the extended Glasgow Outcome Scale (GOSE). A significant correlation between CSF–NFL and GOSE was detected at follow up after 1 year. CSF–NFL also correlated with WFNS and NIHSS on the day of the lumbar puncture. CSF–NFL is a biochemical marker of brain damage correlating to neurological status and long-term outcome after aneurysmal subarachnoid hemorrhage.

Results All but one patient had maximal s-GFAP values above the laboratory reference value (median increased 10-fold). The highest detected levels were seen during the first days after TBI and then decreased gradually. Patients with unfavourable outcome had significantly ( p < 0.001) higher maximal s-GFAP values in the acute phase compared with patients with favourable outcome. All patients ( n = 5) with s-GFAP > 15.04 μg /L died (reference level < 0.15 μg/L). We found no significant difference in the maximal s-GFAP levels of patients with isolated brain injury in comparison with patients with multiple traumas. Conclusion Serum-GFAP is increased during the first days after a severe traumatic brain injury and related to clinical outcome. Keywords Glial fibrillary acidic protein (GFAP) Serum Traumatic brain injury Outcome GOS Biochemical brain markers 1 Introduction Traumatic brain injury is a leading cause of death and disability in children and young adults in developed countries. “The Lund concept”, which advocates aggressive antioedema treatment of high intracranial pressure at moderate central perfusion pressure (CPP), has been reported to improve outcome [3,4] . Despite significant progress in cerebral monitoring it is still difficult to quantify the extent of the primary brain injury and ongoing secondary damage. Because of the limitations of clinical and radiological assessment there has been considerable interest in developing biochemical methods both to measure the extent of brain damage and to improve outcome prediction. S-100 β is a protein of astroglial origin, which has been used as a serum marker of central nervous system (CNS) damage the last decade. An association between clinical outcome and serum concentrations of S-100 β in patients with severe TBI has been shown [5] . However, S-100 is expressed not only in brain tissue but also in a variety of other cell types in both physiological and pathological conditions. Expression of the S-100 β protein has been observed in fat, skin and skeletal muscle [6] . In contrast GFAP is found only in the nervous system. GFAP is a structural protein of the intermediate filament of astroglia. Significantly increased levels of GFAP are observed in cerebrospinal fluid (CSF) as a consequence of acute CNS injury and modestly increased levels of GFAP are seen in patients with astrogliosis [7] . Numerous reports document the usefulness of CSF–GFAP as an indicator of CNS pathology [7–9] . After brain damage proteins like GFAP are released from injured brain cells and appear in the systemic circulation probably directly via passage through a disturbed blood brain barrier. Serum analysis has clinical advantages over CSF measurement and CSF sampling is often contraindicated in patients with severe traumatic brain injury. Missler et al. reported a method for serum-GFAP determinations and preliminary results from patients with severe head trauma in 1999 [1] . They concluded that measurement of GFAP concentrations in blood appeared to have the possibility to identify acute CNS damage. Vos et al. [10] have recently presented a study showing that serum levels of glial and neuronal proteins in the very early phase after TBI predict outcome. A few months later Pelinka et al. [11] confirmed that GFAP is related to outcome after TBI and they also concluded that GFAP is not released after multiple traumas without brain injury. The aim of this prospective study was to evaluate consecutively measurements of serum-GFAP in the acute phase of severe TBI, and to investigate if serum levels are related to outcome after 1 year. 2 Material and methods All patients with severe TBI admitted to the Neurointensive Care Unit (NICU) at Sahlgrenska University Hospital between October 2000 and December 2002 were consecutively included in this prospective study. The trauma was defined as severe if the following criteria were all fulfilled: 1) Reaction Level Scale (RLS) ≥ 4, corresponding to a score sum of ≤ 8 on the Glasgow Coma Scale [12] . 2) A therapeutic indication to monitor intracranial pressure (ICP). 3) Need for ventilator treatment. Some patients were transferred to NICU from other intensive care units, but to be included in the study the first blood sample had to be obtained on day 2 at the latest. The day of the trauma was defined as day 0. Venous blood samples for GFAP were obtained as soon as possible after admission to NICU and then every morning on day number 1, 2, 3, 4, 6, 8 and once in the period between days 11 and 14. Since we aimed to follow the patients until one year after the trauma only patients living in Sweden were included in the study. The Ethics Committee at the University of Göteborg approved the study. The closest relative gave informed consent. All patients were treated according to a standardised protocol, “the Lund concept” aimed at maintaining a cerebral perfusion pressure of > 60 mm Hg and an intracranial pressure of < 20 mm Hg [4,13] . The concept is based on physiological principles for volume regulation of the intracranial compartment. Main components are normovolemia, normotension and reduction of cerebral metabolism and stress response. Gradually increased medical treatment can be combined with neurosurgery. Vital signs and ICP were monitored on an hourly basis. Indication for neurosurgery was clinical and individual. One neuroradiologist (I. N.) reviewed all initial CT according to Marshall categories I–IV. Since she was blinded to clinical and laboratory data, mass lesions were also classified due to their consequences on midline shift and compression of cisterns, and not according to a retrospective analysis of evacuation or not [14] . Thus the CT grading was modified into IV types. After 12 months s-GFAP was reassessed. Outcome was measured using the Glasgow outcome scale (GOS). We used a structured questionnaire based interview [15] . The examiner was blinded to the s-GFAP data. Serum-GFAP was measured using a modified sandwich ELISA as described by Rosengren et al. [7] . In short the assays were run in microtest plates using hen anti-GFAP IgG as the capturing antibody. Duplicate samples of serum (50 μL) were incubated with phosphate buffered saline (50 μL) in each well. Duplicate samples of reference GFAP (0.062–8 μg/L) were incubated in phosphate buffered saline supplemented with 50% normal horse serum (Sigma, USA). Rabbit anti-GFAP IgG was used as the detection antibody. Bound rabbit IgG was detected by the binding of peroxidase-conjugated donkey antirabbit IgG. The colour reaction was developed using ï-phenylenediamine and Perhydrol and the optical density was measured at 490 nm. The concentrations of GFAP were interpolated from the standard curve. Interassay precision was determined by duplicate analyses of two CSF samples and one serum sample at 71 different days. Mean intraassay precision was determined using the same samples run in 4 duplicates at 14 different days. Linearity of the assay was controlled by serial dilutions of three patient samples with very high levels of GFAP in phosphate buffered saline supplemented with 50% normal horse serum. Recovery of the assays was determined by spiking serum from 14 normal controls with reference GFAP at 2.0, 1.0 and 0.50 μg/L. To determine GFAP reference levels serum samples from 218 healthy individuals (mean age 46.0 years, range 18–80) were analysed. In general, statistical analysis was performed using non-parametric tests because the data didn't follow a Gaussian distribution. For comparison between two groups Mann–Whitney U -test was used for continuous variables and for dichotomous variables Fisher's exact test was used. In order to test ordered categorical variables between two groups Mantel Haenszel's test was performed. Pair wise Mann–Whitney tests (Van Elterens test) were used to test differences between groups, adjusting for neurosurgery. All variables significantly ( p < 0.10) correlated to dependent variables were entered in a forward stepwise multiple logistic regression. In that analysis s-GFAP was log transformed due to non-normal distribution. All tests were two-tailed and conducted at 5% significance level. 3 Results Inter- and intraassay precisions of the GFAP ELISA are shown in Table 1 . Interassay precision is close to 11% in the region 1 and 0.25 μg/L, but higher at levels of 0.1 μg/L (22%). Dilution curves of the three serum samples with high levels of GFAP were close to linear and are shown in Fig. 1 . Recovery of GFAP in the 14 spiked serum samples at 2.0, 1.0 and 0.50 μg/L were 54 ± 8% (SD), 52 ± 8%, and 53 ± 8%, respectively. The lower detection limit of the assay was at least 0.0625 μg/L (background + 2SD; n = 14). The mean s-GFAP level of the 218 healthy individuals was 0.061 ± 0.044 μg/L (SD). Levels did not correlate with age. The reference level was set at < 0.15 μg/L (95th percentile). During the inclusion period 222 patients with brain trauma were treated at NICU. Of these 73 patients were considered for enrolment in the study due to the strict criteria for severe TBI. Fourteen patients were not eligible (foreign citizen ( n = 4), lack of informed consent ( n = 4) and inability of taking first sample within time schedule ( n = 6)). Finally included in the study were 59 patients. Table 2 shows the characteristics of the included patients. In the ambulance, 35 of the patients were assessed to be unconscious (RLS ≥ 4) and 17 conscious (RLS ≤ 3) (missing data in 7 cases). At arrival to the primary hospital the physician on call assessed 45 patients to be unconscious and 14 conscious. ICP was continuously recorded by an intraventricular catheter ( n = 57) or intraparenchymatous microtransducer ( n = 2). ICP was at least once above 25 mm Hg in 39 patients and CPP below 60 mm Hg in 45 patients. Neurosurgery, particularly evacuation of haematoma, was indicated in 34 cases (day 0–9). The maximal s-GFAP level was increased in 58 of the 59 patients. Median was 1.17 μg/L and range 0.14–49.58 μg/L (4.52 ± 8.69 μg/L: mean ± SD). The highest levels were seen during the first days (median day 1, range day 0–4) and the values then gradually decreased. The first sample was taken day 0–2 according to the inclusion criteria, median day 1 (day 0 in 17 cases, day 1 in 31 cases and day 2 in 11 cases). In more than half of the study population (36 of 59) the last value in the series was back to a normal level (< 0.15 μg/L) ( Fig. 2 ). There was no difference in maximal s-GFAP levels in the patient group with further neurosurgery in comparison with the rest of the patients. The patient group with isolated brain injury ( n = 13) and the group with additional trauma ( n = 46) did not differ with regard to maximal s-GFAP or outcome. Six patients died during subsequent care at NICU. (Three of them died before day 11). On average, patients were leaving NICU after 14 days. Another five patients died before the follow up after one year. All deaths could be directly attributed to the brain injury, although respiratory failure was often a terminal event. One year after the trauma (mean 12.04 ± 0.88 months) the outcome of the 48 survivors was scored using face-to-face interview in 45 cases, by telephone in 2 cases and in one case from medical records only. One physician (K. N.) performed all interviews with the exception of 2 cases. Patients with unfavourable outcome had significantly ( p < 0.001) higher maximal s-GFAP values compared to patients with favourable outcome ( Fig. 3 ). Unfavourable outcome (dead, vegetative state or severe disability=GOS 1, GOS 2 or GOS 3) was seen in 28 patients with maximal s-GFAP range between 0.38–49.58 μg/L and median 2.72 μg/L. Favourable outcome (moderate disability or good recovery=GOS 4 or GOS 5) was seen in 31 patients with maximal s-GFAP range between 0.14–6.98 μg/L and median 0.85 μg/L. The day of the first sample (0–2) and number of missing values (range 0–6, mean 2, median 1) in the individual series varied. Taking this in consideration we observed that not only the maximal s-GFAP, but also the s-GFAP on day 1, 2, 3, 4, 6, 8 and 11–14, was significantly elevated for the patient group with unfavourable outcome compared to favourable outcome. Furthermore the area under the curve (day 0–11 on x -axis and GFAP on y -axis) gave the same result. All patients ( n = 5) with s-GFAP > 15.04 μg/L died. A maximal s-GFAP value above 6.98 μg/L was not seen in any patient with favourable outcome ( Table 3 ). The difference in s-GFAP levels between favourable and unfavourable outcome remains significant ( p < 0.01) regardless of neurosurgery or not. Analysing other possible prognostic factors for outcome, we found age ( p < 0.05) and initial CT findings ( p < 0.01) to be related to outcome (dichotomised GOS). Level of consciousness (dichotomised) was not related to outcome (dichotomised GOS), neither when estimated in the ambulance or at the primary hospital. Patients with favourable outcome did not differ from patients with unfavourable outcome according to maximal ICP or minimal CPP. CT findings, age and GFAP (log transformed) were considered as clinically relevant independent variables and were therefore included in a forward logistic regression with outcome (dichotomised GOS) as the dependent variable. GFAP was found to be the strongest predictor for outcome ( Table 4 ). Reassessing s-GFAP after one year was possible in 39 cases. Values were normalized in 36 cases (below 0.15 μg/L) and remained slightly increased in 3 patients (0.15–0.19 μg/L). 4 Discussion TBI is graded (mild, moderate or severe) on the basis of level of consciousness or GCS. For patients with severe TBI level of consciousness is not always reliably obtained, often iatrogenically lowered and rapidly changing with time. We wanted to study patients with the “most severe” TBI, i.e. those with need for attention at a specialised neurointensive care unit for more than just observation or postoperative care. Patients, in whom clinical evaluation is difficult to attain on a regular basis, make a biochemical complement valuable. To select these patients we added need for ventilator treatment and indication to monitor ICP to our inclusion criteria for severe TBI. The demographic characteristics of the patients in the study were typical of those in other studies of TBI, with the majority of patients being young men. The maximal s-GFAP level was increased in all but one patient supporting the hypothesis that s-GFAP is increased after a severe traumatic brain injury. The increase was in most cases 10-fold, sometimes 100-fold. Maximal s-GFAP level was most commonly seen on day 1 and in no case later than day 4. The values then gradually decreased. A huge interindividual variation was seen in the sample series. There could be a possibility of missing the peak level in patients with first sample collected day 2, thus probably underestimating the maximal s-GFAP level. (First sample was taken on day 2 for the only patient with a maximal s-GFAP value below the normal reference value). A maximal s-GFAP value above 15.04 μg/L ( n = 5) was not seen in any survivors. Interestingly, 4 of these 5 patients were conscious at admission to the primary hospital. Their CT scans were graded as type IV in 4 cases and as type II in one case. A maximal s-GFAP value above 6.98 μg/L was not seen in any patient with favourable outcome. Thus there is a possibility to predict death or unfavourable outcome in patients with extremely elevated serum-GFAP levels. Patients with mild traumatic brain injuries were not included and consequently it is not possible to evaluate the sensitivity of s-GFAP in this study. Since all the patients in the study were exposed to insertion of an intracranial catheter and most of the patients also underwent neurosurgery, part of the augmentation may be secondary to operative induced brain damage rather than to the traumatic brain injury. However, the maximal values in the patient group with only catheter insertion varied greatly (range 0.14–26.74 μg/L) and the low values observed in some cases indicate that catheter insertion can be done without major increase in s-GFAP. In only two patients serum sample was obtained before the urgent application of the intracranial catheter. These samples were also elevated (0.31 and 5.70 μg/L) obviously due to the brain trauma in itself. There was no difference in maximal s-GFAP levels in the patient group requiring further neurosurgery in comparison to the rest of the patients. Many authors have suggested protein S-100 β to be a good marker of traumatic brain injury. However recent studies demonstrate that not only brain trauma but also peripheral trauma results in high concentrations of S-100 β [16] . The frequent coexistence of severe traumatic brain injury with extracranial injury makes a more brain specific serum marker attractive. In the present study we found no significant difference in the maximal s-GFAP levels of patients with isolated brain injury in comparison with patients with brain injury in combination with fractures and/or injuries to internal organs. This is in accordance with the mainly brain specific location of GFAP. Nevertheless, the present study cannot answer the question of brain specificity of s-GFAP. In the study by Pelinka et al., 13 patients with multiple traumas without TBI were included. They suggest that GFAP is not released without TBI [11] . Further studies focusing on patients with multitrauma and brain specificity remain to be done. The GFAP ELISA used in the present study was originally described for analyses of cerebrospinal fluid [7] . We have modified the procedure slightly to allow for serum determinations. The serum assay seems mainly to be comparable to the one previously published by Missler et al. [1] . The assay is sufficiently reproducible, dilution curves of serum are linear and sensitive enough to be of practical clinical value. However, the recovery is relatively low (52–54%), but on the other hand very constant at the various GFAP levels tested. Recovery has previously been acknowledged as a problem for this GFAP in serum determinations and shown to vary between 60% and 102% [1] . Information collected at baseline can be useful in predicting outcome. Age, GCS, brain stem responses and CT findings have been identified as possible prognostic factors in patients with severe head injury [17] . Not surprisingly we found more unfavourable outcome for elderly. The eight-grade single line scale Reaction Level Scale (RLS) assesses the overall responsiveness or “conscious level” in patients with acute brain disorders. In Sweden RLS is preferred to GCS since even intubated patients and patients with swollen eyelids can be reliably assessed [12] . However we met logistic problems trying to estimate exact RLS in the ambulance and at primary hospital retrospectively. Since this was not possible, dichotomisation in unconscious (RLS ≥ 4) or conscious (RLS ≤ 3) seemed to be the appropriate. Applying this algorithm to reports from the ambulance and at the primary hospital we found no relation to outcome. The variability of timing of the initial CT may limit the usefulness of CT categorisation in predicting outcome. In this study there was an association between initial CT findings and outcome after 1 year. The Glasgow outcome scale (GOS) has become the most widely used scale for assessing outcome after head injury. It is concluded that assessment of the GOS using a standard format with a written protocol is practical and reliable. Dichotomisation to favourable and unfavourable outcome is generally used in the literature. In this study we included five children aged 8–16 years. The questionnaire couldn't be filled in exactly, but there were no clinical difficulties to judge these 5 children's outcome as favourable or unfavourable (four were back to normal school and one had personal assistant and could neither eat nor talk). Applying the King's Outcome Scale for Childhood Head Injury (KOSCHI) [18] as a specific paediatric adaptation of the original adult GOS gives the same result. The major finding of the present study was that patients with unfavourable outcome had significantly higher maximal s-GFAP values than the patient group with favourable outcome. Furthermore, not only the peak concentration, but also the s-GFAP levels on day 1, 2, 3, 4, 6, 8 and 11–14 were significantly higher in the patient group with unfavourable outcome. The temporal profile indicates that samples need not be taken urgent immediately after the trauma. However, the sparse sampling from the initial hours after the trauma leaves the question of the kinetics of s-GFAP during the very early phase unanswered. First sample was obtained 5.5–68 h after the trauma (median after 19 h, time missing in 6 cases). In this context, the findings of Vos et al. [10] supplement our data. They observed increased levels of GFAP in samples obtained within a few hours after TBI (median 2.5 h, range 0.25–30 h) that were related to outcome. In comparison to our study, a higher proportion of their patients had completely normal s-GFAP levels, but besides the very early sampling they also included patients with less severe TBI. The study by Pelinka et al. also included patients with less severe TBI [11] . Our study shows a clear relation to outcome even for samples taken in an extensive range of days after the trauma. There are clinical advantages of this possibility of delayed testing and also of retesting. Our results demonstrate the versatility of s-GFAP analyses after TBI. Over the years outcome after severe TBI has been improved and large databases have been developed. Clinical and radiological assessment still has limitations in predicting outcome after a severe TBI. Novel approaches to better define patient subgroups such as genetic predisposition or patterns of cerebral metabolism and release of biochemical markers offer the hope of improving outcome prediction. Also, biochemical markers of brain damage such as GFAP may be used to monitor therapeutic intervention. Acknowledgments This study was supported by research grants from Elsa and Gustav Lindh foundation, Göteborg foundation for neurological research and the Göteborg Medical Society. References [1] U. Missler M. Wiesmann G. Wittmann O. Magerkurth H. Hagenstrom Measurement of glial fibrillary acidic protein in human blood: analytical method and preliminary clinical results Clin Chem 45 1999 138 141 [3] C. Eker B. Asgeirsson P.-O. Grände W. Schalén C.-H. Nordström Improved outcome after severe head injury with a new therapy based on principles for brain volume regulation and preserved microcirculation Crit Care Med 26 1998 1881 1886 [4] M.R. Wahlström M. Olivecrona L.O. Koskinen B. Rydenhag S. Naredi Severe traumatic brain injury in pediatric patients: treatment and outcome using an intracranial pressure targeted therapy—the Lund concept Intensive Care Med 31 2005 832 839 [5] A. Raabe C. Grolms O. Sorge M. Zimmermann V. Seifert Serum S-100 B protein in severe head injury Neurosurgery 45 1999 477 483 [6] B.W. Schäfer C.W. Heizmann The S100 family of EF-hand calcium-binding proteins: functions and pathology Trends Biochem Sci 21 1996 134 140 [7] L.E. Rosengren C. Wikkelsö L. Hagberg A sensitive ELISA for glial fibrillary acidic protein: application in CSF of adults J Neurosci Methods 51 1994 197 204 [8] A. Aurell L.E. Rosengren B. Karlsson J.-E. Olsson V. Zbornikova K.G. Haglid Determination of S-100 and glial fibrillary acidic protein concentrations in cerebrospinal fluid after brain infarction Stroke 22 1991 1254 1258 [9] M. Tullberg L. Rosengren E. Blomstervall J.-E. Karlsson C. Wikkelsö CSF neurofilament and glial fibrillary acidic protein in normal pressure hydrocephalus Neurology 50 1998 1122 1127 [10] P.E. Vos K.J. Lamers J.C. Hendriks M. van Haaren T. Beems C. Zimmerman Glial and neuronal proteins in serum predict outcome after severe traumatic brain injury Neurology 62 2004 1303 1310 [11] L.E. Pelinka A. Kroepfl R. Schmidhammer M. Krenn W. Buchinger H. Redl Glial fibrillary acidic protein in serum after traumatic brain injury and multiple trauma J Trauma 57 2004 1006 1012 [12] J.-E. Starmark D. Stalhammar E. Holmgren The Reaction Level Scale (RLS 85). Manual and guidelines Acta Neurochir (Wien) 91 1988 12 20 [13] P.O. Grände B. Asgeirsson C.H. Nordström Physiologic principles for volume regulation of a tissue enclosed in a rigid shell with application to the injured brain J Trauma 42 1997 23 31 [14] L.F. Marshall S.B. Marshall M.R. Klauber M. van Berkum Clark H.M. Eisenberg J.A. Jane A new classification of head injury based on computerized tomography J Neurosurg 75 1991 14 20 [15] L.J.T. Wilson L.E.L. Pettigrew G.M. Teasdale Structured interviews for the Glasgow outcome scale and the extended Glasgow outcome scale: guidelines for their use J Neurotrauma 15 1998 573 585 [16] R.E. Anderson L.O. Hansson O. Nilsson R. Dijlai-Merzoug G. Settergren High serum S100B levels for trauma patients without head injuries Neurosurgery 48 2001 1255 1260 [17] J. Ono A. Yamaura M. Kubota Y. Okimura K. Isobe Outcome prediction in severe head injury: analyses of clinical prognostic factors J Clin Neurosci 8 2001 120 123 [18] M. Crouchman L. Rossiter T. Colaco R. Forsyth A practical outcome scale for paediatric head injury Arch Dis Child 84 2001 120 124

Background: This study investigates mortality and morbidity in patients with traumatic brain injury (TBI) who developed episode(s) of transtentorial herniation. The transtentorial herniation was defined as a deterioration of consciousness accompanied by uni‐ or bilateral pupil dilatation. Methods: The medical records of all patients with traumatic brain injury admitted during 1999 to the Neuro‐ or General Intensive Care Units at Sahlgrenska University Hospital were analyzed, and patients with at least one episode of transtentoryal herniation were included. Information regarding patient age, gender, type of trauma, initial GCS, precipitating reason for herniation, uni‐/bilateral pupil dilatation, treatment(s) and outcome after at least 6 months, assessed with the Glasgow Outcome Scale (GOS), was collected from medical records. Results: The study included 27 patients, average age 44 years (range 6–81), with a male proportion of 81%. The majority of the patients were victims of traffic accidents and falls. The results demonstrated that 16/27(59%) of the patients had a favorable outcome (GOS 4/5), 4/27(15%) were severely disabled (GOS 3), none was vegetative (GOS 2) and 7/27(26%) died (GOS 1). When analyzing patient subgroups, best outcome was found in children where 3/4 (75%) had a GOS 4/5. Conclusion: Transtentorial herniation is a serious consequence of supratentorial edema/mass lesions in patients with TBI. However, with aggressive neurointensive care and neurosurgical treatments we found a 59% patient incidence of a favorable outcome.

Csajbok, L. Z.; Öst, M.; Nyhlén, K.; Blennow, K.; Rydenhag, B.; Nellgård, B. Author Information

Naredi, Silvana; Koskinen, Lars-Ove; Grände, P-O; Nordström, Carl-Henrik; Nellgård, Bengt; Rydenhag, Bertil; Vegfors, Magnus Author Information

We read with interest the report of Bayindir et al1Bayindir O Akpinar B Can E et al.The use of the 5-HT3-receptor antagonist ondansetron for the treatment of postcardiotomy delirium.J Cardiothorac Vasc Anesth. 2000; 14: 288-292Abstract Full Text Full Text PDF PubMed Google Scholar of 35 patients with postcardiotomy delirium treated with the 5-HT3 receptor antagonist ondansetron. In 1995, we performed a similar pilot study2Nellgard P Nellgard B A new treatment for postoperative delirium after cardiac surgery?.in: 11th World Congress of Anaesthesiologists, Sydney1996Google Scholar with the same impressive results, similarly without side effects. Barbara Costall from the UK reported several animal studies, which also had good results, demonstrating that ondansetron could be successfully used on scopolamine-induced delirium and alcohol dependency. A dentist with alcoholic drinking problems was treated with ondansetron and remained sober during the 4 weeks of medication. Also, 2 nurses with nicotine dependency were treated for 2 weeks with ondansetron without smoking relapse. However, the manufacturer of ondansetron was uninterested in our results and thus further studies were not performed at that time. Ondansetron`s mode of action is very interesting and one might speculate that it may reduce the inhibition of acetylcholine release. This would increase the brain acetylcholine transmittor, thus reducing the delirium. In patients with Parkinson's disease, treatment with traditional antipsychotic agents like haloperidol, often used to treat postcardiotomy delirium, worsen their stiffness and for them ondansetron may be the perfect treatment. For these patients, and in some others, the alternative to ondansetron would be a propofol infusion, which would increase the already high cost of ICU care.