BACKGROUND:The study explores whether the cerebral biochemical pattern in patients treated with hemicraniectomy after large middle cerebral artery infarcts reflects ongoing ischemia or non-ischemic mitochondrial dysfunction.METHODS:The study includes 44 patients treated with decompressive hemicraniectomy (DCH) due to malignant middle cerebral artery infarctions. Chemical variables related to energy metabolism obtained by microdialysis were analyzed in the infarcted tissue and in the contralateral hemisphere from the time of DCH until 96 h after DCH.RESULTS:Reperfusion of the infarcted tissue was documented in a previous report. Cerebral lactate/pyruvate ratio (L/P) and lactate were significantly elevated in the infarcted tissue compared to the non-infarcted hemisphere (p < 0.05). From 12 to 96 h after DCH the pyruvate level was significantly higher in the infarcted tissue than in the non-infarcted hemisphere (p < 0.05).CONCLUSION:After a prolonged period of ischemia and subsequent reperfusion, cerebral tissue shows signs of protracted mitochondrial dysfunction, characterized by a marked increase in cerebral lactate level with a normal or increased cerebral pyruvate level resulting in an increased LP-ratio. This biochemical pattern contrasts to cerebral ischemia, which is characterized by a marked decrease in cerebral pyruvate. The study supports the hypothesis that it is possible to diagnose cerebral mitochondrial dysfunction and to separate it from cerebral ischemia by microdialysis and bed-side biochemical analysis.

OBJECTIVES:In patients with large middle cerebral artery (MCA) infarcts, maximum brain swelling leading to cerebral herniation and death usually occurs 2-5 days after onset of stroke. The study aimed at exploring the pattern of compounds related to cerebral energy metabolism in infarcted brain tissue.METHODS:Forty-four patients with malignant MCA infarcts were included after decision to perform decompressive hemicraniectomy (DHC). Cerebral energy metabolism was in all patients monitored bedside by 1-3 microdialysis catheters inserted into the infarcted hemisphere during DHC. In 29 of the patients, one microdialysis catheter was also placed in the non-infarcted hemisphere. MCA blood-flow velocity was monitored bilaterally by transcranial Doppler ultrasound.RESULTS:The interstitial glucose levels were in both sides within normal limits throughout the monitoring period. Mean lactate/pyruvate (LP) ratio was very high in infarcted tissue immediately after DHC. The ratio slowly decreased but did not reach normal level during the study period. In the infarcted hemisphere, MCA blood-flow velocities increased from approximately 42 cm/s 1 day prior to DHC (nine of nine patients) to approximately 60 cm/s at day 4.CONCLUSIONS:Normal interstitial glucose level in the infarcted hemisphere in combination with substantial MCA blood-flow velocities bilaterally even before DHC was performed indicates that malignant brain swelling usually commences when the embolus/thrombosis has been largely resolved and recirculation of the infarcted area has started. The protracted increase of the LP ratio in infarcted tissue might indicate mitochondrial dysfunction.

Hypothermia is shown to be beneficial for the outcome after a transient global brain ischaemia through its neuroprotective effect. Whether this is also the case after focal ischaemia, such as following a severe traumatic brain injury (TBI), has been investigated in numerous studies, some of which have shown a tendency towards an improved outcome, whereas others have not been able to demonstrate any beneficial effect. A Cochrane report concluded that the majority of the trials that have already been published have been of low quality, with unclear allocation concealment. If only high‐quality trials are considered, TBI patients treated with active cooling were more likely to die, a conclusion supported by a recent high‐quality Canadian trial on children. Still, there is a belief that a modified protocol with a shorter time from the accident to the start of active cooling, longer cooling and rewarming time and better control of blood pressure and intracranial pressure would be beneficial for TBI patients. This belief has led to the instigation of new trials in adults and in children, including these types of protocol adjustments. The present review provides a short summary of our present knowledge of the use of active cooling in TBI patients, and presents some tentative explanations as to why active cooling has not been shown to be effective for outcome after TBI. We focus particularly on the compromised circulation of the penumbra zone, which may be further reduced by the stress caused by the difference in thermostat and body temperature and by the hypothermia‐induced more frequent use of vasoconstrictors, and by the increased risk of contusional bleedings under hypothermia. We suggest that high fever should be reduced pharmacologically.

Acta Anaesthesiologica ScandinavicaVolume 51, Issue 10 p. 1294-1296 Conventional treatments for severe head injury: are they effective, ineffective, or even harmful? P.-O. Grände, Corresponding Author P.-O. Grände 1Department of Anaesthesiology and Intensive Care, Lund University Hospital, Sweden, 2Department of Neurosurgery, Umeå University Hospital, Sweden, 3Department of Anaesthesiology and Intensive Care, Umeå University Hospital, Sweden, 4Clinic of Neurosurgery, Neuroscience Centre, Rigshospitalet, Copenhagen, DenmarkPer-Olof Grände Department of Anaesthesiology and Intensive CareUniversity Hospital of LundSwedene-mail: [email protected]Search for more papers by this author 1 L.-O. Koskinen, L.-O. Koskinen 1Department of Anaesthesiology and Intensive Care, Lund University Hospital, Sweden, 2Department of Neurosurgery, Umeå University Hospital, Sweden, 3Department of Anaesthesiology and Intensive Care, Umeå University Hospital, Sweden, 4Clinic of Neurosurgery, Neuroscience Centre, Rigshospitalet, Copenhagen, DenmarkSearch for more papers by this author 2 S. Naredi, S. Naredi 1Department of Anaesthesiology and Intensive Care, Lund University Hospital, Sweden, 2Department of Neurosurgery, Umeå University Hospital, Sweden, 3Department of Anaesthesiology and Intensive Care, Umeå University Hospital, Sweden, 4Clinic of Neurosurgery, Neuroscience Centre, Rigshospitalet, Copenhagen, DenmarkSearch for more papers by this author 3 P. Reinstrup, P. Reinstrup 1Department of Anaesthesiology and Intensive Care, Lund University Hospital, Sweden, 2Department of Neurosurgery, Umeå University Hospital, Sweden, 3Department of Anaesthesiology and Intensive Care, Umeå University Hospital, Sweden, 4Clinic of Neurosurgery, Neuroscience Centre, Rigshospitalet, Copenhagen, DenmarkSearch for more papers by this author 1 B. Romner, B. Romner 1Department of Anaesthesiology and Intensive Care, Lund University Hospital, Sweden, 2Department of Neurosurgery, Umeå University Hospital, Sweden, 3Department of Anaesthesiology and Intensive Care, Umeå University Hospital, Sweden, 4Clinic of Neurosurgery, Neuroscience Centre, Rigshospitalet, Copenhagen, DenmarkSearch for more papers by this author 4 P.-O. Grände, Corresponding Author P.-O. Grände 1Department of Anaesthesiology and Intensive Care, Lund University Hospital, Sweden, 2Department of Neurosurgery, Umeå University Hospital, Sweden, 3Department of Anaesthesiology and Intensive Care, Umeå University Hospital, Sweden, 4Clinic of Neurosurgery, Neuroscience Centre, Rigshospitalet, Copenhagen, DenmarkPer-Olof Grände Department of Anaesthesiology and Intensive CareUniversity Hospital of LundSwedene-mail: [email protected]Search for more papers by this author 1 L.-O. Koskinen, L.-O. Koskinen 1Department of Anaesthesiology and Intensive Care, Lund University Hospital, Sweden, 2Department of Neurosurgery, Umeå University Hospital, Sweden, 3Department of Anaesthesiology and Intensive Care, Umeå University Hospital, Sweden, 4Clinic of Neurosurgery, Neuroscience Centre, Rigshospitalet, Copenhagen, DenmarkSearch for more papers by this author 2 S. Naredi, S. Naredi 1Department of Anaesthesiology and Intensive Care, Lund University Hospital, Sweden, 2Department of Neurosurgery, Umeå University Hospital, Sweden, 3Department of Anaesthesiology and Intensive Care, Umeå University Hospital, Sweden, 4Clinic of Neurosurgery, Neuroscience Centre, Rigshospitalet, Copenhagen, DenmarkSearch for more papers by this author 3 P. Reinstrup, P. Reinstrup 1Department of Anaesthesiology and Intensive Care, Lund University Hospital, Sweden, 2Department of Neurosurgery, Umeå University Hospital, Sweden, 3Department of Anaesthesiology and Intensive Care, Umeå University Hospital, Sweden, 4Clinic of Neurosurgery, Neuroscience Centre, Rigshospitalet, Copenhagen, DenmarkSearch for more papers by this author 1 B. Romner, B. Romner 1Department of Anaesthesiology and Intensive Care, Lund University Hospital, Sweden, 2Department of Neurosurgery, Umeå University Hospital, Sweden, 3Department of Anaesthesiology and Intensive Care, Umeå University Hospital, Sweden, 4Clinic of Neurosurgery, Neuroscience Centre, Rigshospitalet, Copenhagen, DenmarkSearch for more papers by this author 4 First published: 18 October 2007 https://doi.org/10.1111/j.1399-6576.2007.01475.xCitations: 1Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Citing Literature Volume51, Issue10November 2007Pages 1294-1296 RelatedInformation

BACKGROUNDRecent studies in man have shown that cerebral blood flow increases during inhalation of nitrous oxide (N2O), a finding which is believed to be a result of an increased cerebral metabolic rate (CMR). However, this has not previously been evaluated in man.METHODSRegional CMR(glu) (rCMR(glu)) was measured three dimensionally with positron emission tomography (PET) after injection of 2-(18F)fluoro-2-deoxy-D-glucose in 10 spontaneously breathing men (mean age 31 yr) inhaling either N2O 50% in O2 30% or O2 30% in N2.RESULTSGlobal CMR(glu) in young men was 27 (3) micromol 100 g(-1) min(-1) [mean (SD)]. Inhalation of N2O 50% did not change global CMR(glu) [30 (5) micromol 100 g(-1) min(-1)] significantly, but it changed the distribution of the metabolism in the brain (P<0.0001 analysis of variance). Compared with inhalation of O2 30% in N2, N2O 50% inhalation increased the metabolism in the basal ganglia [14 (17)%, P<0.05] and thalamus [22 (23) %, P<0.05]. There was a prolonged metabolic effect of N2O inhalation seen on a succeeding PET scan with oxygen-enriched air (P<0.0001) performed 1 h after the N2O administration.CONCLUSIONSInhalation of N2O 50% did not change global CMR(glu), but the metabolism increased in central brain structures, an effect that was still present 1 h after discontinuation of N2O.

Background: Selective dorsal rhizotomy (SDR) is an operation method that decreases the degree of spasticity with long-lasting beneficial effects for children with spastic diplegia. Children undergoing SDR are postoperatively in severe pain, a pain related to both the extensive surgical exposure with multilevel laminectomy and the nerve root manipulation. Various pain management strategies for children undergoing SDR have been published. The postoperative pain treatment is a vital part of the management. The aim of this study was to estimate the number of centers performing SDR, the frequency of SDR surgery and to investigate pain management of the different centers. Methods: A questionnaire comprising 7 questions was sent by mail and/or e-mail to a total of 59 potential centers performing SDR, centers that have published material concerning SDR or centers that have been recommended. Forty-seven (80%) centers responded to the questionnaire; 11 of them do not presently perform SDR surgery, and the remaining 36 centers constitute the material of the present study. Results: 23 of the 36 centers use Peacock’s operation technique and 8 centers use Park’s technique. Continuous intravenous infusion of opioids for postoperative pain treatment is used by 17 (47%) of the centers. Seven (19%) centers use the epidural (ED) approach for treating postoperative pain and 6 (17%) centers use intrathecal (IT) pain treatment. The duration of intravenous ED or IT pain relief ranged from 24 h up to 7 days. To evaluate pain relief, 25 (70%) centers used some form of pain scale. Conclusion: The most common operation techniques in use today are described by Peacock or by Park, with an estimated number of procedures of more than 487/year in 36 centers. The majority of the centers seem to have a satisfactory pain management strategy. These centers administer continuous infusions of opioids, with an intravenous, ED or IT approach, and incorporate the use of a pain assessment tool to evaluate pain relief.

SummaryBackground: Children undergoing selective dorsal rhizotomy (SDR) experience severe pain postoperatively; a pain related to both the extensive surgical exposure with multilevel laminectomy and nerve root manipulation. We sought to define an optimal dose of continuous intrathecal (IT) morphine and bupivacaine to treat this severe pain. The aim of this study was to compare two different concentrations of morphine in a fixed dose of bupivacaine with regard to the analgesic effect and survey if they differed in side effects.Methods: Twenty‐six children, aged 2.7–7.4 years undergoing SDR were included in this study. Postoperatively 11 children received a continuous infusion of morphine 0.4 μg.kg−1.h−1 and bupivacaine 40 μg.kg−1.h−1 (low‐dose group) and 15, a continuous infusion of morphine 0.6 μg.kg−1.h−1 and bupivacaine 40 μg.kg−1.h−1 (high‐dose group). The Behavioral Observational Pain Scale (BOPS) was used to evaluate pain.Results: Better pain relief was obtained in the high‐dose group seen in lower BOPS score compared with the low‐dose group [P = 0.03, Fisher's permutation test and P = 0.06 Wilcoxon–Mann–Whitney (WMW) test]. The low‐dose group received seven times as much ketobemidone 0.43 ± 0.54 mg.kg−1 48 h−1 compared with 0.06 ± 0.09 mg.kg−1 48 h−1 in the high‐dose group (P = 0.0005 Fisher's permutation test, P = 0.0017 WMW test). There was no statistical difference in pruritus and postoperative nausea and vomiting between the groups. Respiratory and hemodynamic depression was not found.Conclusion: This study shows that, compared with low‐dose, the higher dose of continuous IT morphine combined with bupivacaine, significantly reduce pain score and postoperative intravenous analgesic requirements without increasing adverse effects.

OBJECT:Intracerebral microdialysis has attracted increasing interest as a monitoring technique during neurological/neurosurgical intensive care. The purpose of this study was to compare cerebral energy metabolism, an indicator of secondary excitotoxic injury and cell membrane degradation close to focal traumatic lesions ("penumbra zones") and in remote and apparently intact brain regions of the ipsilateral and contralateral hemispheres.METHODS:The study included 22 consecutive patients with a mean age 44 +/- 17 years and an estimated postresuscitation Glasgow Coma Scale motor score less than 5. Altogether 40 microdialysis catheters with radiopaque tips were inserted. Two catheters could not be localized on postoperative computerized tomography (CT) scans and were excluded from the analysis. The perfusates were analyzed at the patient's bedside for levels of glucose, pyruvate, lactate, glutamate, and glycerol with the aid of a CMA 600 Analyzer. The positions of eight (22%) of the 36 catheters were reclassified after a review of findings on CT scans. Except for pyruvate the values of all biochemical variables and the lactate/pyruvate (L/P) ratio were significantly different in the penumbra zone when compared with mean values found in "normal" tissue ipsilateral to the parenchymal damage and in contralateral normal tissue (p < 0.001). In the penumbra zone a slow normalization of the L/P ratio and levels of glutamate and glycerol were observed. In normal tissue these parameters remained within normal limits.CONCLUSIONS:Data obtained from intracerebral microdialysis can be correctly interpreted only if the locations of the catheters as they relate to focal brain lesions are visualized. A "biochemical penumbra zone" surrounds focal traumatic brain lesions. It remains to be proven whether therapeutic interventions can protect the penumbra zone from permanent damage.

BACKGROUND In patients with intracranial pathology, especially when comatose, it is desirable to have knowledge of the intracranial pressure (ICP). To investigate the relationship between ICP and transcranial Doppler (TCD) derived pulsatility index (PI) in neurosurgical patients, a prospective study was performed on patients admitted to our neurointensive care unit.METHODS Daily TCD mean flow velocity (mFV) measurements were made. TCD measurements were routinely performed bilaterally on the middle cerebral artery (MCA). PI (peak systolic-end diastolic velocities/mean flow velocity) was calculated.RESULTS Eighty-one patients with various intracranial disorders who had an intraventricular catheter for registration of the ICP were investigated: 46 (57%) patients had subarachnoid hemorrhage, 21 (26%) patients had closed head injury, and 14 (18%) patients had other neurosurgical disorders. A total of 658 TCD measurements were made. ICP registrations were made parallel with all TCD measurements. A significant correlation (p < 0.0001) was found between the ICP and the PI with a correlation coefficient of 0.938: ICP = 10.93 x PI - 1.28.In the ICP interval between 5 to 40 mm Hg the correlation between ICP and PI enabled an estimation of ICP from the PI values with an SD of 2.5. The correlation between the cerebral perfusion pressure (CPP) and PI was significant (p < 0.0001) with a correlation coefficient of -0.493. When separating the measurements in severely elevated (>120 cm/s) and subnormal (<50 cm/s) TCD mFV values, the correlation coefficient between ICP and PI was 0.828 (p < 0.002) and 0.942 (p < 0.638), respectively.CONCLUSIONS Independent of the type of intracranial pathology, a strong correlation between PI and ICP was demonstrated. Therefore, PI may be of guiding value in the invasive ICP placement decision in the neurointensive care patient. (C) 2004 Elsevier Inc. All rights reserved.

OBJECTIVE:The reason for longstanding fatigue following aneurysmal subarachnoidal hemorrhage (SAH) is still not clarified. The bleed from supratentorial aneurysms is often in the vicinity of the hypothalamus and pituitary gland making an endocrine dysfunction plausible.METHODS:Ten patients with post-SAH fatigue were investigated with 3D-CBF (SPECT) and underwent an evaluation of the pituitary function.RESULTS:Five had normal pituitary function. Disturbances in the gonadotropin function was detected in three patients and suspected in two. The mean insulin-like growth factor I (IGF-I) value of the patients was in the lower part of the reference range. In the patients with endocrine dysfunction, the 3D-CBF was pathologic in the central structures of the basal region.CONCLUSIONS:The present results indicate that an aneurysmal SAH may result in partially impaired pituitary capacity. This deficit may contribute to fatigue after aneurysmal SAH, but cannot solely explain this disorder. SPECT identified regional tissue damage in the patients with pituitary dysfunction after SAH.

BACKGROUND:In patients with severe traumatic brain lesions, the lower limit for cerebral perfusion pressure (CPP) is controversial. The aim of this prospective study was to assess this limit from bedside measurements of cerebral energy metabolism and to clarify whether the penumbra zone surrounding a focal lesion is more sensitive to a decrease in CPP than less-injured areas.METHODS:Fifty patients with severe head injury were included after evacuation of an intracranial hematoma and/or focal brain contusion. They were treated according to intensive care routine (Lund concept), including continuous monitoring of intracranial pressure. One microdialysis catheter was inserted in less-injured brain tissue ("better" position), and one or two catheters were inserted into the boundary of injured cerebral cortex ("worse" position). Concentrations of glucose, pyruvate, and lactate were analyzed and displayed bedside and were related to CPP (n = 29,495).RESULTS:Mean interstitial glucose concentration was unaffected by the level of the CPP within the studied ranges. Increases in lactate concentration (P = 0.0008) and lactate-pyruvate ratio (P = 0.01) were obtained in the "worse" but not in the "better" position at CPP less than 50 mmHg compared with the same positions at CPP greater than 50 mmHg.CONCLUSIONS:The study results support the view that CPP may be reduced to 50 mmHg in patients with severe traumatic brain lesions, provided that the physiologic and pharmacologic principles of the Lund concept are recognized. In the individual patient, preservation of normal concentrations of energy metabolites within cerebral areas at risk can be guaranteed by intracerebral microdialysis and bedside biochemical analyses.

BACKGROUND:Retrograde intubation has been accepted internationally as a viable alternative for managing the difficult airway. Various techniques have been described to perform this procedure, however, difficulties have arisen on account of problems with suboptimal materials. We therefore describe a retrograde intubation technique using the knife and stiff plastic introducer from a Mini-Trach II set from Portex Ltd (Kent, UK).METHODS:The cricothyroid membrane was identified and using the knife from the mini-trach set, incised longitudinally. The plastic introducer was inserted through the incision and maneuvered out through the mouth providing a guide over which the endotracheal tube was threaded. The technique was evaluated on 20 cadavers and thereafter used in four patients.RESULTS:Mean intubation time in the 20 cadavers was 6.7 s (range 3-10) from incision to removal of the guide. Also, the technique was used successfully in four patients in whom anterograde attempts failed. In one of these patients the retrograde intubation was life saving.CONCLUSION:Retrograde intubation with a stiff curved plastic introducer was rapid and easy in cadavers and in four patients. In emergency situations where conventional intubation fails it may be life saving.

Protein S100B has been shown to increase in serum and cerebrospinal fluid (CSF) in various neurological diseases. However, the levels of S100B in conjunction with cerebral herniation have not been studied and the significance of extracerebral S100B has become an important issue. We report on a multi-trauma patient in whom cerebral herniation occurred 2 days after admission. Following this, organ-harvesting procedures were performed for transplantation. We measured serial serum S100B during both the ongoing herniation and the following extracerebral surgery. We found that S100B levels seemed to peak immediately prior to cerebral herniation and then decreased shortly thereafter and concluded that the source of the measured serum S100B in this patient was of predominately cerebral origin. In conjunction with the organ harvesting procedure S100B levels increased, indicating that extracerebral sources of the protein also exist.

The aim of our retrospective study was to determine the extent to which diffusion- and perfusion- weighted MRI combined with conventional MRI could be helpful in the evaluation of intensive care unit (ICU) patients who have unknown or unclear cerebral pathology underlying a serious clinical condition. Twenty-one ICU patients with disparity between the findings on brain CT scan and their clinical status were studied. All patients underwent conventional MR and diffusion-weighted imaging and 14 also had MR perfusion studies. Abnormalities were present on diffusion-weighted imaging of 17 of the 21 patients and on perfusion-weighted studies of 7 of 14 patients. The MRI results changed the preliminary/working diagnosis in six patients. In eight other patients, MRI revealed additional pathology that had not been suspected clinically, and/or characterized more closely findings that had already been detected by CT or suspected clinically. MRI showed abnormalities in four of the five patients who had normal CT. MRI findings suggested a negative clinical outcome in all nine patients who subsequently died. MRI findings also suggested positive long-term outcome in five of nine patients who improved significantly as based on Glasgow and extended Glasgow outcome scales. In the three unconscious patients who had normal diffusion- and perfusion-weighted imaging the clinical outcome was good. This study suggests that MRI in seriously ill ICU patients with unclear cerebral pathology can provide information that changes, characterizes, or supports diagnoses and/or prognoses and therefore facilitates further management.

Summary. Summary. Background: Arterial vasospasm after subarachnoid hemorrhage may cause cerebral ischemia. Treatment with hemodilution, reducing blood viscosity, and hypervolemia, increasing cardiac performance and distending the vasospastic artery, are clinically established methods to improve blood flow through the vasospastic arterial bed. Method: Eight patients with transcranial Doppler verified vasospasm after subarachnoid hemorrhage were investigated with global (two-dimensional 133 Xenon) and regional (three-dimensional 99 m Tc-HMPAO) cerebral blood flow (CBF) measurements, before and after 1/iso- and 2/hypervolemic hemodilution. Hematocrit was reduced to 0.28 from 0.36. Hypervolemia was achieved by increasing blood volume by 1100 ml. Findings: Isovolemic hemodilution increased global cerebral blood flow from 52.25±10.12 to 58.56±11.73 ml * 100 g −1 * min −1 (p<0.05), but after hypervolemic hemodilution CBF returned to 51.38±11.34 ml * 100 g −1 * min −1 . Global cerebral delivery rate of oxygen (CDRO 2 ) decreased from 7.94±1.92 to 6.98±1.66 ml * 100 g −1 * min −1 (p<0.001) during isovolemic hemodilution and remained reduced, 6.77±1.60 ml * 100 g −1 * min −1 (p<0.001), after the hypervolemic hemodilution. As a test of the hemodilution effect on regional CDRO 2 an ischemic threshold was defined as the maximal amount of oxygen transported by a CBF of 10 ml * 100 g −1 * min −1 at a Hb 140 g/l which corresponds to a CDRO 2 of 1.83 ml * 100 g −1 * min −1 . The brain volume with a CDRO 2 exceeding the ichemic threshold was 1300±236 ml before intervention. After isovolemic hemodilution the non-ischemic brain volume was reduced to 1206±341 (p<0,003). After hypervolemic hemodilution the non-ischemic brain volume remained reduced at 1228±347 ml (p<0.05). Interpretation: The present study of controlled isovolemic hemodilution demonstrated increased global CBF, but there was a pronounced reduction in oxygen delivery capacity. Both CBF and CDRO 2 remained decreased during further hypervolemic hemodilution. We conclude that hemodilution to hematocrit 0.28 is not beneficial for patients with cerebral vasospasm after SAH.

Selective dorsal rhizotomy is a surgical procedure with a selective division of posterior spinal nerve rootlets to treat spasticity in children. The extensive surgical procedure with multilevel laminectomies and the nerve root manipulation result in intense pain postoperatively. Two intrathecal (IT) regimes of pain treatment were compared in these children, concerning their pain relief and possible side-effects. In a prospective study, 12 children (3-6 years of age) with six in each group, received either intermittent IT morphine (5 microg x kg(-1) four times a day) or continuous infusion of a mixture of bupivacaine (40 microg x kg(-1) x h(-1)) and morphine (0.6 microg x kg(-1) x h(-1)). Pain score was lower in the bupivacaine/morphine group (0.2 +/- 1.1) compared to intermittent morphine (2 +/- 2.4) on a scale from 0 to 6 (P less than or = 0.0001). Bupivacaine/morphine resulted in a lower, but not significant, difference in pruritus and lower muscle spasm. Haemodynamic and ventilatory parameters did not differ between the groups. Intrathecal continuous infusion of bupivacaine and morphine was superior to intermittent morphine in the treatment of pain after selective dorsal rhizotomy operations.