Kathrin König

Treatment of Elevated Intracranial Pressure by Infusions of 10% Saline in Severely Head Injured Patients

The management of intracranial pressure (ICP) is a factor in outcome of patients with head trauma. However, recent studies have revealed that the current strategies, which have been applied to control ICP for adequate cerebral perfusion, are unsatisfactory. Against this background, the efficacy of short-term infusions of hypertonic saline on ICP was investigated. In severely head injured (SHI) patients, hypertonic saline (100 ml 10% NaCl) was administered when standard agents (mannitol, sorbitol, THAM) failed in reducing ICP. To evaluate the pressure reduction after saline infusions the resulting ICP relaxations were analysed statistically in respect to the parameters amplitude, duration and dynamic behaviour of the ICP responses. In 42 randomized relaxations, the relative ICP decrease was 43% [28%-58%] (median [interquartile range]). The corresponding pressure drop was 18 mmHg [15-27 mm Hg]. Relaxations lasted for 93 min [64-126 min] and a relative ICP minimum was reached 26 min [12-33 min] after infusion. In the individual cases the temporal course of the parameters amplitude and decline interval depict a tendency toward lower and higher values, respectively, under conditions of a generally increasing ICP. As expected, the infusion of hypertonic saline reduces ICP in patients suffering from SHI. The pressure drop, duration and dynamic behaviour are suspected to depend both on the pressure level to reduce and concomitant medications.

Head Trauma in Children, Part 3: Clinical and Psychosocial Outcome After Head Trauma in Children

With the aim of determining long-term outcome, the authors approached 38 families (average 2.1 years after trauma) with a questionnaire, following the acute-clinical treatment of head trauma of their children. Long-term damage was restricted almost exclusively to patients presenting with a Glasgow Coma Score ≤8. Paresis (16%), cranial nerve damage (13%), incontinence (5%), or coordinative disturbances (18%) continued. The older children stated that they influenced their life to a great extent (11%). Furthermore, many had mental and cognitive problems that occur quite frequently even in children with light head trauma and often only manifest after release from hospital. This causes problems and results in inferior performance (26%), especially at school, which is further complicated through lengthy periods of absence. The parents, especially, mentioned behavioral problems such as social withdrawal or aggressive demeanor, which led to tension also inside the family. A persistent vegetative state is rare after head trauma in children.

Head Trauma in Children, Part 2: Course and Discharge With Outcome

To minimize the secondary brain damage, we analyzed the effect of cerebral perfusion pressure—orientated management and tried to find factors of clinical management and biochemical findings that influence clinical, cognitive, and psychosocial outcome. Management at intensive care unit was standardized. A standardized (short form 36 health survey) and nonstandardized split questionnaire explored long-term outcome. Glutamic-oxaloacetic-transaminase, creatine kinase MB or glucose are markers for bad outcome (P < .05). Patients with cerebral perfusion pressure values below the recommended standard for just a single occurrence had significantly worse outcome (P = .0132). Mean arterial pressure, central venous pressure, and heart rate alone do not correlate with outcome. At least 1 occurrence of mean arterial pressure and central venous pressure below the lower limits resulted in a poor outcome (P = .035). Cerebral perfusion pressure—guided therapy seems to prevent further brain damage and results in outcome scores that are comparable to those children with head trauma exhibiting symptoms of mild brain edema.

Head trauma in children, part 1: admission, diagnostics, and findings.

The objective of this study is to describe and to determine the preclinical situation and early in-clinical situation, diagnostic findings, and factors influencing the outcome of severe head trauma in children. Records of 48 children (0-16 years) were analyzed during a 3-year interval. Correlations with the outcome (Glasgow Outcome Scale) were determined by focusing on different scales, clinical findings, biochemistry, and clinical course features. The initial shock index had a major relevance (P = .0089). Systolic blood pressure (P = .0002) and bradycardia (P = .035) were important factors. Assessing the severity of trauma according to the Glasgow Coma Score, the most accurate parameter for outcome is based on the detailed quality of ‘‘eye opening’’ (P = .0155). Pupillary motoricity at the accident site (P = .002) and emergency room (P = .0004) are strong predictors. Preclinical measurements of stabilization and oxygenation have the same impact as the in-clinical management.

The use of recombinant activated factor VII in neurosurgery

BACKGROUND Bleeding complications in neurosurgery often take alarming proportions without major hemodynamic effect or impairment of coagulation physiology because severe neurologic deficits are to be expected. Any measures used to stabilize or normalize coagulation are therefore of great interest. Administration of packed red cells, fresh frozen plasma, and platelet concentrates is associated with volume loading, which is suspected to multiply the secondary brain damage, for example, by the development of an edema. In this respect, the administration of rFVIIa may develop into a new option associated with low-volume administration. CASE DESCRIPTIONS We report on 5 neurosurgical patients to whom rFVIIa was given at doses of 51 to 202 microg/kg of body weight for the treatment of severe intraoperative bleeding (n = 3) or as prophylaxis of bleeding (n = 2). The operation was completed successfully in all patients after administration of rFVIIa, with stabilization of the coagulation status. CONCLUSION Therefore, reported cases constitute an approach in treatment and prophylaxis of bleeding complications in neurosurgery. There are reports of thromboembolic events in use of rFVIIa, particularly in unlabeled use. But according to our findings and current literature, there is no evidence of higher risk of thromboembolic adverse events in treatment with rFVIIa. However, the number of patients presented does not allow any final assessment to be made as to whether the properties of rFVIIa are of particular benefit for neurosurgical patients. Further studies with appropriate study design are required to verify effects observed in this investigation.

Assessment of Cerebral Blood Flow by Means of Blood-Flow-Volume Measurement

To the Editor: With great interest we read in Stroke that a working group around Soustiel1 compared cerebral blood flow (CBF) as measured by 133xenon clearance technique with blood-flow-volume (BFV) measurements from the internal carotid artery (ICA). Soustiel et al found well-correlated …

Stationarity in Neuromonitoring Data

PURPOSE Signals reflecting the metabolic and circulatory status of an injured central nervous system are normally corrupted systematically. The patient is part of a therapeutic control-loop and the signals acquired are rather determined by the quality of control (stationarity of signals) than by the underlying pathological process. METHODS To verify the control-loop hypothesis, neuromonitoring data from 12 randomly selected severely head injured patients (initial GCS ≤ 8, 7 men, 5 women) were analysed for circulatory (blood pressure, intracranial pressure [ICP], cerebral perfusion pressure [CPP]) and metabolic (arterial blood gases, jugular bulb oxygenation [SjvO(2)], brain tissue oxygen partial pressure [ptiO(2)]) variables (n = 10). A total of 120 time series of generally not equidistant sample intervals were assessed for stationarity by Wallis & Moores runs test. RESULTS Non-stationarity could only be proven in 23 time series, i.e. the control-loop hypothesis was violated. Trends were mainly found in CPP (n = 5) and ICP (n = 4). The remaining cases spread out on all but one (temperature) signal. Nine patients showed at least one time series with a trend. One patient had clear trends in five out of ten variables that focused on SjvO(2), ptiO(2), ICP and CPP. CONCLUSIONS Absence of stationarity in about 20% of time series is credited to an effective therapeutic control-loop. For analytical purposes, however, the benefit seems to be overestimated. Consequently, neuromonitoring should be considered the analysis of short-term disturbances that are intentionally compensated for by a short response time. Information content is thus reduced even if the number of sensor devices increases.

Analysis of Intracranial Pressure Time Series Using Wavelets (Haar Basis Functions)

PURPOSE Transforming intracranial pressure (ICP) into frequency domain commenced in the early 1980s, arriving at the conclusion that cerebrospinal dynamics were mapped by ICP spectral composition. Classical analysis tools were not suitable for handling intrinsic signal non-stationarity. To overcome inherent obstacles we introduce a novel approach based upon wavelets. METHODS During routine diagnostic volume pressure testing epidural ICP was acquired in 118 patients with suspected cerebrospinal fluid circulatory disorders. Pressure was digitised and conditioned to separate low frequent signal components (<heart rate). ICP fluctuations were computed by subtraction of original and low frequent ICP constituents. Subsequently, multiresolution analysis was performed on fluctuations by discrete Haar wavelet transform and coefficients displayed in dyadic fashion (scalogram). RESULTS Decomposition of ICP fluctuations led to typical patterns in the scalogram. Episodes of pathological wave activity and artificial ICP changes were topographically detectable in the time frequency plane. CONCLUSIONS The wavelet approach is a simple yet powerful signal processing method to estimate both static and dynamic properties of ICP in various clinical scenarios. It therefore outclasses classical spectral transforms that are limited to analysing real-world data. Haar wavelets are fast and robust. Their disadvantages seem not to counterbalance the advantages in this biomedical application.

Cerebral Blood Flow in Chronic Hydrocephalus A Parameter Indicating Shunt Failure — New Aspects

Prediction of outcome after shunt-therapy in chronic hydrocephalus syndrome is uncertain. Pathology reveals an impairment of cerebral blood flow (CBF). Based on this, we evaluated CBF and its significance for the assessment of prognosis. In 21 patients (mean age 69 years) selected for surgery, CBF was measured by PET (15O-H2O) before, about one week and 7 months (n = 14) after shunting. CBF was computed by a 1-compartmental model in the territories of the ACA, MCA and PCA. One PET slice in the height of the maximum projection of both cellae mediae was chosen. CBF data were standardized by cluster analysis. Three CBFClusters with significantly different CBF levels prior to shunting in the ACA, MCA and PCA territory, respectively, referred to the sample average (38.2 ml/100 ml/min) were found. These CBFClusters differed in clinical outcome: almost 50% and 90% of patients improved clinically in CBFCluster I, with a perfusion level lower than average, after one week and 7 months, respectively. In contrast, patients of CBFCluster II with an average perfusion did not improve. CBF changes 7 months after shunting related to global CBF before surgery showed a relationship with the clinical course. Clinical outcome corresponded with preoperative global CBF values. Cerebral blood flow lower than average forecasts clinical improvement. Our results suggest that measurement of CBF adds to the indication for surgery.

Klinik und Therapie der Claudicatio spinalis bei Spinalkanalstenosen

Pseudoclaudication causes complaints which originate from compression of neural structures of the narrow lumbar spinal canal due to degenerative changes with osteoarthrotic thickening and osteophytosis of the facet joints and the hypertrophied yellow ligament. Frequently bulging discs or a segmental loss of stability increase the compression. The diagnosis is made clinically because although CT or MRI enable a confirmation of the diagnosis, they do not, however, allow an adequate correlation of the derived results with the clinical findings. The complaints worsen under exertion with symptoms in the legs and back pain or a combination of both as well. A surgical procedure should be considered when conservative treatment fails, the VAS score usually exceeds 4 points, and the limitation of the walking capability falls below 500 m. If there is a permanent neurological deficit, an early decision can be appropriate and there is an absolute and urgent indication in signs of a cauda equina lesion. The objective postoperative results of open decompressive surgery are encouraging and associated with low complication rates. The subjective satisfaction of the patients is even better. Even eldery patients profit from an increasing mobility accompanied by the chance to retain self-sufficiency.