The electrospray ionization (ESI) voltage is shown to interfere with liquid chromatographic separations performed with packed porous graphitic carbon (PGC) capillary columns. This interference is ascribed to the presence of an electric field over the conductive column in the absence of an earth point between the column and the ESI emitter. The current evolved alters the chromatographic behavior of the catecholamine metabolite 3-O-methyl-DOPA significantly, as both peak splitting and a dramatic decrease in the retention time were observed. Furthermore, the response from the mass spectrometer was decreased by 33% at the same time. A related compound, tyrosine, exhibited decreased retention times but no peak splitting, whereas no shifts in the retention times (or peak splitting) were seen for the less retained dopamine and noradrenaline. When the current through the PGC column was eliminated by the use of an earth point between the column and the ESI emitter, the chromatographic behavior of the column was found to return slowly to normal after hours of equilibration with 60 : 40 (v/v) methanol-ammonium formate buffer of pH 2.9. The behavior of the PGC column with and without the earth point was found to be highly reproducible during a period of 1 month. We propose that the effect of the ESI voltage on the chromatographic behavior of the PGC column is due to associated redox reactions affecting both the PGC particles and the analytes. It is concluded that (for analytical reasons), care should be taken to ensure that no current is flowing through the chromatographic system when interfacing PGC columns, and conducting parts in general, to ESI mass spectrometry.

BackgroundTwo randomised controlled trials (RCTs) of decompressive craniectomy (DC) in traumatic brain injury (TBI) have shown poor outcome, but there are considerations of how these protocols relate to real practice. The aims of this study were to evaluate usage and outcome of DC and thiopental in a single centre.MethodThe study included all TBI patients treated at the neurointensive care unit, Akademiska sjukhuset, Uppsala, Sweden, between 2008 and 2014. Of 609 patients aged 16 years or older, 35 treated with DC and 23 treated with thiopental only were studied in particular. Background variables, intracranial pressure (ICP) measures and global outcome were analysed.ResultsOf 35 DC patients, 9 were treated stepwise with thiopental before DC, 9 were treated stepwise with no thiopental before DC and 17 were treated primarily with DC. Six patients received thiopental after DC. For 23 patients, no DC was needed after thiopental. Eighty-eight percent of our DC patients would have qualified for the DECRA study and 38% for the Rescue-ICP trial. Favourable outcome was 44% in patients treated with thiopental before DC, 56% in patients treated with DC without prior thiopental, 29% in patients treated primarily with DC and 52% in patients treated with thiopental with no DC.ConclusionsThe place for DC in TBI management must be evaluated better, and we believe it is important that future RCTs should have clearer and less permissive ICP criteria regarding when thiopental should be followed by DC and DC followed by thiopental.

BackgroundHyperthermia is a common secondary insult in traumatic brain injury (TBI). The aim was to evaluate the relationship between hyperthermia and intracranial pressure (ICP), and if intracranial compliance and cerebral blood flow (CBF) pressure autoregulation affected that relationship. The relationships between hyperthermia and cerebral oximetry (BtipO2) and cerebral metabolism were also studied.MethodsA computerized multimodality monitoring system was used for data collection at the neurointensive care unit. Demographic and monitoring data (temperature, ICP, blood pressure, microdialysis, BtipO2) were analyzed from 87 consecutive TBI patients. ICP amplitude was used as measure of compliance, and CBF pressure autoregulation status was calculated using collected blood pressure and ICP values. Mixed models and comparison between groups were used.ResultsThe influence of hyperthermia on intracranial dynamics (ICP, brain energy metabolism, and BtipO2) was small, but individual differences were seen. Linear mixed models showed that hyperthermia raises ICP slightly more when temperature increases in the groups with low compliance and impaired CBF pressure autoregulation. There was also a tendency (not statistically significant) for increased BtipO2, and for increased pyruvate and lactate, with higher temperature, while the lactate/pyruvate ratio and glucose were stable.ConclusionsThe major finding was that the effects of hyperthermia on intracranial dynamics (ICP, brain energy metabolism, and BtipO2) were not extensive in general, but there were exceptional cases. Hyperthermia treatment has many side effects, so it is desirable to identify cases in which hyperthermia is dangerous. Information from multimodality monitoring may be used to guide treatment in individual patients.

BackgroundTo improve neurointensive care (NIC) and outcome for traumatic brain injury (TBI) patients it is crucial to define and monitor indexes of the quality of patient care. With this purpose we established the web-based Uppsala TBI register in 2008. In this study we will describe and analyze the data collected during the first three years of this project.MethodsData from the medical charts were organized in three columns containing: 1) Admission data; 2) Data from the NIC period including neurosurgery, type of monitoring, treatment, complications, neurological condition at discharge, and the amount of secondary insults; 3) Outcome six months after injury. Indexes of the quality of care implemented include: 1) Index of improvement; 2) Index of change; 3) The percentages of ‘Talk and die' and ‘Talk and deteriorate' patients.ResultsAltogether 314 patients were included 2008–2010: 66 women and 248 men aged 0–86 years. Automatic reports showed that the proportion of patients improving during NIC varied between 80% and 60%. The percentage of deteriorated patients was less than 10%. The percentage of Talk and die/Talk and deteriorate cases was <1%. The mean Glasgow Coma Score (Motor) improved from 5.04 to 5.68 during the NIC unit stay. The occurrences of secondary insults were less than 5% of good monitoring time for intracranial pressure (ICP) >25 mmHg, cerebral perfusion pressure (CPP) <50 mmHg, and systolic blood pressure <100 mmHg. Favorable outcome was achieved by 64% of adults.ConclusionThe Uppsala TBI register enables the routine monitoring of NIC quality indexes.

The patients at a neurointensive care unit are frequently cared for in many ways, day and night. The aim of this study was to investigate the amount of secondary insults related to oral care, repositioning, endotracheal suctioning, hygienic measures, and simultaneous interventions at a neurointensive care unit with standardized care and maximum attention on avoiding secondary insults. The definition of a secondary insult was intracranial pressure > 20 mm Hg, cerebral perfusion pressure < 60 mm Hg and systolic blood pressure < 100 mm Hg for 5 minutes or more in a 10-minute period starting from when the nursing intervention began. The insult minutes did not have to be consecutive. The study included 18 patients, seven women and 11 men, aged 36-76 years with different neurosurgical diagnoses. The total number of nursing interventions analyzed was 1,717. The most common kind of secondary insults after a nursing measure was high intracranial pressure (n = 93) followed by low cerebral perfusion pressure (n = 43) and low systolic blood pressure (n = 14). Repositioning (n = 39) and simultaneous interventions (n = 32) were the nursing interventions causing most secondary insults. There were substantial variations between the patients; only one patient had no secondary insult. There were, overall, a limited number of secondary insults related to nursing interventions when a standardized management protocol system was applied to reduce the occurrence of secondary insults. Patients with an increased risk of secondary insults should be recognized, and their care and treatment should be carefully planned and performed to avoid secondary insults.