Higher sensitivity for traumatic cerebral microbleeds at 7 T ultra-high field MRI: is it clinically significant for the acute state of the patients and later quality of life?

Background

The present study evaluates the possible prognostic benefits of 7 T susceptibility weighted imaging (SWI) of traumatic cerebral microbleeds (TMBs) over 3 T SWI to predict the acute clinical state and subjective impairments, including health-related quality of life (HRQOL), after closed head injury (CHI).

Methods

The study group comprised 10 participants with known TMBs All subjects underwent 3 T magnetic resonance imaging (MRI) and 7 T MRI, respectively. Location and count of TMBs were independently evaluated by two neuroradiologists. The initial Glasgow Coma Scale (GCS), the duration of coma and further clinical data were taken from the patients records. HRQOL was assessed by means of a questionnaire. Memory complaints and neurological symptoms were inquired at the time of the MRI examinations.

Results

SWI revealed a total of 485 TMBs at 3 T, 584 TMBs at 7 T with similar spatial resolution, and 684 TMBs at 7 T with a factor of 10 higher spatial resolution. The TMBs depicted by 7 T high-resolution SWI were correlated with the duration of coma (Spearman's rho of 0.77). The corresponding association with TMBs in 3 T MRI SWI showed a Spearman's rho of 0.71. The initial GCS score and TMBs correlated with a Spearman's rho of -0.35 at 3 T SWI MRI and a rho of -0.33 at 7 T high-resolution SWI, respectively. The physical aspect of HRQOL correlated substantially with the count of TMBs (rho = 0.44 for 3 T SWI and rho = 0.35 for both 7 T SWI sequences, respectively).

Conclusions

The number of TMBs showed a substantial association with indicators of the acute clinical state and chronic neurobehavioral parameters after CHI, but there was no additional advantage of 7 T MRI. These preliminary findings warrant a larger prospective study for the future.

Diffuse axonal injury at ultra-high field MRI

Objective

Diffuse axonal injury (DAI) is a specific type of traumatic brain injury caused by shearing forces leading to widespread tearing of axons and small vessels. Traumatic microbleeds (TMBs) are regarded as a radiological marker for DAI. This study aims to compare DAI-associated TMBs at 3 Tesla (T) and 7 T susceptibility weighted imaging (SWI) to evaluate possible diagnostic benefits of ultra-high field (UHF) MRI.

Material and Methods

10 study participants (4 male, 6 female, age range 20-74 years) with known DAI were included. All MR exams were performed with a 3 T MR system (Magnetom Skyra) and a 7 T MR research system (Magnetom 7 T, Siemens AG, Healthcare Sector, Erlangen, Germany) each in combination with a 32-channel-receive coil. The average time interval between trauma and imaging was 22 months. Location and count of TMBs were independently evaluated by two neuroradiologists on 3 T and 7 T SWI images with similar and additionally increased spatial resolution at 7 T. Inter- and intraobserver reliability was assessed using the interclass correlation coefficient (ICC). Count and diameter of TMB were evaluated with Wilcoxon signed rank test.

Results

Susceptibility weighted imaging revealed a total of 485 TMBs (range 1-190, median 25) at 3 T, 584 TMBs (plus 20%, range 1-262, median 30.5) at 7 T with similar spatial resolution, and 684 TMBs (plus 41%, range 1-288, median 39.5) at 7 T with 10-times higher spatial resolution. Hemorrhagic DAI appeared significantly larger at 7 T compared to 3 T (p = 0.005). Inter- and intraobserver correlation regarding the counted TMB was high and almost equal 3 T and 7 T.

Conclusion

7 T SWI improves the depiction of small hemorrhagic DAI compared to 3 T and may be supplementary to lower field strengths for diagnostic in inconclusive or medicolegal cases.

General versus locoregional anesthesia in carotid surgery: A prospective randomised trial

Background: To evaluate the influence of anesthetic technique on perioperative neurological and cardiopulmonary complication rates in patients undergoing carotid endarterectomy. Patients and methods: 186 patients with symptomatic internal carotid artery (ICA) stenosis > 70% or asymptomatic ICA stenosis > 80% were prospectively randomized for either locoregional (LA) or general anesthesia (GA). Results: Neurological complication rates were similar in both groups (GA 2% vs. LA 2%). Cardiopulmonary complication rates were not significantly different (GA 4% vs LA 1%).There were no stroke-related deaths, but one patient from the GA group died from severe postoperative pneumonia. Thus, a significant difference in combined stroke / cardiopulmonary related death between the two groups (GA 1% vs LA 0%) could not be found. However, perioperative cardiopulmonary monitoring showed that significantly more patients operated under general anesthesia had hypertensive events, with systolic blood pressure values greater than 180 mmHg on postoperative day one. There were no differences in the number of postoperatively hypotensive episodes (systolic blood pressure values < 100 mmHg) between the two groups. Conclusions: Significant differences in the perioperative neurological and cardiopulmonary complication rates between general and locoregional anesthesia in patients undergoing carotid endarterectomy could not be observed.

Affective components and intensity of pain correlate with structural differences in gray matter in chronic back pain patients

Although chronic back pain is one of the most frequent reasons for permanent impairment in people under 65, the neurobiological mechanisms of chronification remain vague. Evidence suggests that cortical reorganisation, so-called functional plasticity, may play a role in chronic back pain patients. In the search for the structural counterpart of such functional changes in the CNS, we examined 18 patients suffering from chronic back pain with voxel-based morphometry and compared them to 18 sex and age matched healthy controls. We found a significant decrease of gray matter in the brainstem and the somatosensory cortex. Correlation analysis of pain unpleasantness and the intensity of pain on the day of scanning revealed a strong negative correlation (i.e. a decrease in gray matter with increasing unpleasantness/increasing intensity of pain) in these areas. Additionally, we found a significant increase in gray matter bilaterally in the basal ganglia and the left thalamus. These data support the hypothesis that ongoing nociception is associated with cortical and subcortical reorganisation on a structural level, which may play an important role in the process of the chronification of pain.

3. Internationales Symposium: „Autologe Transfusion - Von der Euphorie zur Ratio: Praktisches Handeln aus wissenschaftlicher Sicht” (Teil II)Relevante Aspekte bei der Bestrahlung und Retransfusion von maschinell aufbereitetem Wundblut - aus anästhesiologischer Sicht

The requirement for intraoperative blood salvage (IBS) in cancer surgery stems from the high transfusion rate, the unfavourable effects of an anaemia, and the impact of transfusion risks like immunomodulation in tumor patients. The advantages of IBS are availability, the low waste rate, and the excellent quality of this autologous, unstored blood. The only effective elimination of the risk of tumor cell dissemination after retransfusion of wound blood is achieved by blood irradiation. The combination of the established methods of IBS and blood irradiation is practical, and allows a very efficient saving of blood. For Jehovah's witnesses it may open the possibility for tumor surgery. From an anaesthesiological point of view it is part of the therapy, but any context that puts it compatible to medicolegal regulations is welcome. For him as the one responsible for the therapy of intraoperative blood loss it represents the safest and best blood for an optimal hemotherapy in tumor patients. In addition, first data indicate a better outcome of these patients.

Ergebnisqualität bei der Maschinellen Autotransfusion und Einflussfaktoren

Also intraoperative blood salvage (IBS) requires a system for quality management with controls of product an process quality. These can help early detection of malfunctions. For proper reaction and for improvement of quality a deep understanding of the process of blood salvage is necessary. This is supported by experimental testing of equipment, programs, and process variables, and by analysis of their effects on the process. The use of fresh whole blood and total protein as wash-out parameter in these tests is superior to outdated banked RBC and free haemoglobin. The process of aspiration turns out much less harmful than expected, when tested with fresh blood. Low wash volumes, fast washing rates, and half full bowls should be avoided. Plasma wash-out is improved by slower washing or by higher wash volumes, but the latter decrease RBC recovery. Such quality management helps to provide blood of excellent quality by IBS for optimal haemotherapy.

[Anaesthesia for radiation therapy of brain tumours in children. A multidisciplinary challenge]

Radiation therapy of childhood intracranial malignancies is always a challenge for radiation oncologists, anaesthetists and paediatric oncologists. Detailed knowledge of the course of the disease prior to radiation therapy and a critical evaluation of the child's actual physical status are mandatory in each case. Furthermore the anaesthetist should be informed about the child's individual preferences and aversions. The optimum prearrangement of the radiation therapy is of paramount importance. Interdisciplinary communication structures which must always involve the child's parents have to be established. Perfect adjustment of the mask that fixes the head during each radiation procedure is necessary to give the child the possibility to breathe spontaneously without an endotracheal tube or a laryngeal mask. Two case reports highlight these aspects of the complex procedure of paediatric radiation therapy which are relevant for the anaesthetist.

Composition and characteristics of an autologous thrombocyte gel

BACKGROUND

The purpose of the current study was to characterize and compare an autologous thrombocyte gel containing several blood components with a commercially available glue.

MATERIALS AND METHODS

Twenty-five volunteers had blood drawn, and lab values, characteristics of the platelet-enriched plasma (PRP), thrombocyte aggregation, electron microscopic examinations, and the breaking strength were determined and compared to a commercial glue.

RESULTS

Overall 65% of the total thrombocytes could be isolated from the volunteers and an enrichment of 300% with an autotransfusion device could be achieved. Thrombocyte aggregation as a marker for thrombocyte function decreased from 92% in patients to 71% in the PRP. The autologous glue demonstrated a significant reduced breaking strength (0,76 N/cm(3)) compared to the commercial glue (7.42 N/cm(2)), P < 0.05. The decrease in breaking strength could be correlated with the thrombocyte concentration, P < 0.05.

CONCLUSIONS

In the present study we have shown that an autologous platelet-enriched plasma cannot be used as a glue in the common sense to seal stitches or prosthesis. Platelet gels, however, have a high concentration of platelets that release the bioactive proteins and growth factors are necessary to initiate and accelerate tissue repair and enhance dermal and epidermal regeneration. To evaluate the possible clinical implication prospective, randomized studies should be performed to examine the effect of autologous plasma platelet-enriched plasma on wound healing.

[Brachial plexus. Long lasting neurological deficit following interscalene blockade of the brachial plexus]

An interscalene block of the brachial plexus was combined with general anaesthesia for repair of a complex chronic lesion of the shoulder. The localisation of the plexus with electro-stimulation and the injection of Bupivacain 0.5% were accomplished easily and without painful sensations. 48 hours later the block was still partially present. Paraesthesia and a sensory and motor innervation deficit affected mainly the dorsal fascicle, but also areas innervated by the median and lateral fascicles. The deficit did not completely disappear for 18 month. The cause could have been due to direct traumatisation during blockade or operation, toxic action of the injected substance (Bupivacain 0.5%, 30 ml), distension of the plexus, a cervical syndrome or an aseptic plexitis, although a definite determination is not possible. However, the pattern of the lesion and the lack of pain during localisation of the plexus and injection favour traumatisation during the acromioplasty.

[Patient-controlled analgesia: psychological predictors of pain experience, analgesic consumption and satisfaction]

INTRODUCTION

The present study examines the relationship between different psychological variables (including anxiety, depression, locus of control, expectations of pain intensity and social support) and postoperative pain, analgesic consumption and satisfaction with the pain management in a study sample of 67 patients.

METHODS

Intravenous patient-controlled analgesia was used for postoperative analgesia. Pain intensity was assessed by numerical rating scales and obtained from the PCA-report. On the fourth day after surgery, the patients estimated retrospectively the pain intensity of the first day.

RESULTS

The results show that postoperative pain experience correlates significantly with several variables raised preoperatively. The retrospective variables were predicted by psychological measures. There was no relationship to the pain measurements of the PCA-report.

CONCLUSIONS

While pain experience could be predicted by stable psychological traits, satisfaction was associated with the state variables, like anxiety and depression. It is precisely satisfaction with the pain therapy that could be improved by special preoperative psychological training and/or general information about the postoperative pain intensity.

[How reliable is our memory for acute postoperative pain]

OBJECTIVES

Clinicians use patients' recall of pain as an important source of evidence both in diagnosis and in assessing improvements following treatment. Yet very little is known about the accuracy of these retrospective accounts up to now.

METHODS

We examined patients' retrospective evaluations of the pain they experienced at the first postoperative day and related these evaluations to the pain intensity which was recorded in the PCA-report.

RESULTS

We found that recall was moderately accurate. Patients mostly overestimated their pain intensity. We could demonstrate that patients who overestimated their pain differed significantly from those who did not. The patients who overestimated showed no significant pain relief over the first three postoperative days. Other influences were the pain intensity of the third day and patients' expectations of the postoperative pain intensity. Our results could be embedded within the theoretical framework of general memory research.

CONCLUSIONS

We conclude that real-time evaluations of pain intensity should be recorded additionally to retrospective accounts. Retrospective ratings are important too, because we suggest that the memory of pain more than the experience of pain itself form the basis of patients' future decisions about treatment including their compliance and their satisfaction with pain management.

Blood irradiation for intraoperative autotransfusion in cancer surgery: demonstration of efficient elimination of contaminating tumor cells

BACKGROUND

Intraoperative blood salvage is contraindicated in cancer surgery because of contaminating tumor cells and the risk of systemic dissemination. On the basis of the radiosensitivity of cancer cells, irradiation of salvaged blood with 50 Gy is proposed as a way to allow return of salvaged blood.

STUDY DESIGN AND METHODS

Elimination of tumor cells by blood irradiation was studied in vitro with cells from 10 cell lines and from 14 tumor preparations after their addition to red cells in high numbers, or with blood shed during cancer surgery. Before and after gamma radiation, tumor cells were isolated by density gradient centrifugation and tested for their proliferative capacity in a cell colony assay. DNA metabolism was analyzed by incorporation of 5' bromodesoxyuridine.

RESULTS

Survival curves of cells from various tumors confirmed D0 (the dose required to reduce the fraction of surviving cells to 37 percent of the original value) values in the range of 1.2 to 2.2 Gy. After irradiation of tumor cell-contaminated blood with 50 Gy, no cell colony formation was observed, which indicates a reduction rate exceeding 10 log. Irradiated cancer cells showed viability, but no residual DNA metabolism.

CONCLUSION

The level of inactivation by a 50-Gy dose far exceeds that needed to inactivate the number of proliferating tumor cells observed or expected in wound blood. These results provide the experimental basis for the clinical application of blood irradiation for intraoperative blood salvage in cancer surgery.

Variability of outcome after lumbar disc surgery

STUDY DESIGN

A prospective, consecutive study of patients' outcome at three subsequent follow-up times after lumbar disc surgery.

OBJECTIVES

To evaluate how consistent outcome remained in a group of patients after lumbar disc surgery.

SUMMARY OF BACKGROUND DATA

Despite similar results concerning the overall outcome, results in most studies show different prognostic factors for lumbar disc surgery at different follow-up times. A reason for this observation could be that patients shift to a different outcome group during the observation period.

METHODS

Before surgery and at the three follow-ups (3, 12, and 28 months after surgery) the Low Back Outcome Score was calculated. Groups with favorable and unfavorable outcome were determined after each follow-up according to the scores.

RESULTS

Ninety-eight patients were studied. Forty percent showed an unstable outcome at different follow-up times. For each follow-up, three prognostic factors were determined. No prognostic factor showed significance at all follow-up examinations.

CONCLUSIONS

Patients whose outcome after lumbar disc surgery does not remain stable present a major problem in the calculation of prognostic factors.

[Evaluation of postoperative pain therapy with patient-controlled analgesia from the viewpoint of the patient and nursing staff]

Patient-controlled analgesia has been proven to be an effective technique in postoperative pain management. The aim of our study was to evaluate PCA on general surgery wards. 311 patients and their nurses were questioned about their experiences in using PCA for postoperative pain management. Satisfaction with pain relief judged by both patients and nursing staff, incidence of negative side effects and technical problems were studied. The great majority of patients and nursing staff rated the quality of pain relief as being satisfactory. Incidence of negative side effects was extraordinarily low. There was no respiratory depression observed, technical problems hardly arose. Most of the patients coped very well with operating their PCA-pumps. We conclude that PCA is a safe and effective method in postoperative pain management on surgical wards. Under the condition of regular monitoring of pain intensity, of analgesic consumption, level of sedation and of side effects by trained medical and nursing staff, monitoring of respiration and vigilance is not necessary for the PCA regimen we used.

[Patient-controlled analgesia. PCA in a three year old child after traumatic amputation]

We report the case of a 3-year-old boy, who received long-term parent-controlled analgesia after traumatic amputation of one leg. He underwent surgery 17 times for a period of 25 days. Parent-controlled analgesia was started four days after admission because analgesia with non-opioid analgetics (acetaminophen) proved to be insufficient. The pump was set to a bolus-dose of 23 micrograms kg-1 piritramide (dipidolor) and a lockout interval of 10 minutes. Permitted maximum cumulative dose in four hours was 5 mg piritramide. There was no continuous infusion of opioid. PCA and possible adverse effects were explained to the mother. A monitoring regimen was used to assess efficacy (pain intensity estimated by the mother), adverse effects (sedation score, occurrence of nausea and vomiting) and piritramide consumption. For fear of side effects opioid administration was insufficient in the beginning. After three days the mother used the PCA effectively and no additional analgesic medication was required. Nausea or other side effects were not observed. After seven days opioid consumption nearly doubled. Apart from tolerance, this might have resulted from the mother's caution in the first days. After 17 days the PCA was discontinued. Oral analgetics (tramadol) controlled the pain adequately. Management of postoperative pain in children is difficult and too often insufficient. PCA is a safe and effective method of providing postoperative pain relief. Feasibility was shown in adolescents and, more recently, in children aged five years and over. Only few reports are available describing long term use of PCA in children younger than five years. Our case suggests that PCA may also be used effectively and safely in children younger than five years, if experienced staff, a monitoring regimen and cooperative and well instructed parents are available.

[Irradiation of wound blood from tumor surgery for retransfusion]

Intraoperative autotransfusion is contraindicated in tumor surgery because of the danger of tumor cell dissemination. We have tested the elimination of tumor cells in blood by irradiation for safe retransfusion. Tumor cells of various origin were mixed to washed red blood cells from volunteer blood donations. The blood was irradiated with 50 Gy. After isolation of the tumor cells by density gradient centrifugation they were tested for colony formation. While with different tumor cell lines (n = 12) 10 cells were sufficient to yield several colonies, as many as 10(10) cells did not result in any colony after irradiation of the blood. Similar results were obtained with cells cultured from blood salvaged during tumor surgery (n = 3), and with tumor cells prepared from various carcinomas (n = 10). Flow cytometric DNA analysis showed the irradiated cells in mitotic arrest. None of these cells had residual DNA metabolism expressed as incorporation of BrdUrd. We were able to demonstrate a rate of reduction in dividing cells of up to 10(9). With the typical irradiation sensitivity of tumor cells, with D0 values between 1 and 2 Gy, a dose of 50 Gy results in an effective log 12 reduction, sufficient for safe elimination of tumor cells found in shed blood. No adverse effects of the gamma-irradiation on the blood cells are to be expected, especially since the blood is retransfused without storage.