[Severe respiratory insufficiency as manifestation of a pulmonary metastasized Ewing's sarcoma]. / Schwerste Atemnot als Manifestation eines pulmonal metastasierten Ewing-Sarkoms.

A previously unknown tumor led to respiratory failure due to pulmonary metastasis in a young male. The shortness of breath began gradually and then rapidly progressed within 2 weeks. With the cause of respiratory failure still unclear, extracorporeal membrane oxygenation (ECMO) treatment was initiated to gain time for the definitive diagnosis. After the exclusion of infectious lung diseases the diagnosis could be made by a biopsy. Surprisingly, a Ewing's sarcoma was diagnosed and chemotherapy was initiated. This led to tumor regression within about 3 weeks, so that the patient could be successfully weaned from ECMO treatment.

[Blockade of the distal sciatic nerve in the supine position with a newly developed ultrasound probe holder]. / Distale Ischiadikusblockade in Rückenlage mittels neu entwickelter Ultraschallsondenselbsthalterung.

Sonographically controlled blockade of the distal sciatic nerve is usually performed by placing the ultrasound probe on the dorsal side of the thigh. This requires positioning maneuvers (prone or side positioning) of the patient as well as additional assistance. In order to avoid these positioning maneuvers, a positioning aid with integrated ultrasound probe holder has been developed and its practicability was examined on patients with lower limb surgery. The sonographically controlled block of the sciatic nerve was performed with the patient under general anesthesia and in a supine position with the help of the new positioning aid with an integrated ultrasound probe holder. A total of >100 patients were treated, who underwent elective lower leg, ankle or foot surgery with a continuous blockade of the distal sciatic nerve using catheters for postoperative analgesia. The advantages are easy performance, hands-free needle movement and catheter placement. The disadvantages might be the need for in-plane catheter placement and a fixed ultrasound angle.

Cumulative changes in weight but not fluid volume balances reflect fluid accumulation in ICU patients.

BACKGROUND: The cumulative fluid balance of critically ill patients seems to be an outcome-relevant variable. However, there are no validated data for their reliability calculated for longer (> 5 days) periods of time. METHODS: All ICU patients ≥ 18 years, with an ICU stay ≥ 5 days and a body weight ≤ 195 kg were evaluated from 1 January 2013 to 31 December 2013. Daily standardized weighing was performed using bed-integrated scales simultaneously with the daily 24-h fluid balance. Simultaneously, a fluid balance without and with insensible perspiration (10 ml/kg/day) was calculated for each 24 h. Primary endpoint: difference between cumulative fluid balance and body weight changes at the day of transfer to the normal ward or the day of death in the ICU, respectively, in each patient. All data are presented as medians with interquartile ranges (IQR) with 25 and 75 percentiles (IQR/25/75) unless otherwise noted. RESULTS: One hundred and six critically ill patients were evaluated; 82 survivors and 24 nonsurvivors. Cumulative 24-h fluid balances rose continuously while body weight decreased over time. Correction of cumulative fluid balances for insensible perspiration (10 ml/kg/day) also did not match with body weight changes. Only survivors had a significant loss in body weight -1.8 (27.5/-6.1/1.0) kg. CONCLUSIONS: Assuming that changes in body weight reflect changes in whole body water content cumulative daily fluid volume balances without or with correction for insensible water loss are not useful for estimating cumulative fluid balance of ICU patients. Survivors but not nonsurvivors had a significant loss of weight over time.

[Methohexital for analgosedation of ventilated intensive care patients : prospective nonrandomized single center observational study on incidence of delirium]. / Methohexital zur Analgosedierung bei beatmeten Intensivpatienten : Prospektive nichtrandomisierte "Single-center"-Observationsstudie zur Delirinzidenz.

BACKGROUND: Delirium is defined by the Diagnostic and Statistical Manual of Mental Disorders, fourth edition, text revision (DSM-IV-TR) as a potentially reversible disturbance of consciousness and a change of cognition caused by a medical condition, drug intoxication, or medication side effect. Delirium affects up to 80 % of intensive care unit (ICU) patients and is associated with increased morbidity and mortality. One risk factor for development of delirium in ventilated intensive care unit patients is sedation. The German S3 guidelines on "Analgesie, Sedierung und Delirmanagement in der Intensivmedizin" (analgesia, sedation and delirium management in intensive care medicine) of the DGAI (German Society for Anesthesiology and Intensive Care Medicine) and the DIVI (German Interdisciplinary Association for Intensive Care and Emergency Medicine) recommend midazolam and propofol for sedation, although both drugs are associated with a high incidence of delirium. AIM: Within the framework of this study the question arose whether the barbiturate methohexital could be associated with a lower incidence of delirium in comparison to midazolam or propofol in analgosedated and ventilated ICU patients. MATERIAL AND METHODS: This was a prospective nonrandomized observational cohort study in a mixed medical surgical intensive care unit. Patients ventilated within 72 h after admittance were consecutively allocated to either propofol/remifentanil versus methohexital/remifentanil (expected ventilation duration ≤ 7 days) or midazolam/fentanyl versus methohexital/fentanyl (expected ventilation duration > 7 days) by the attending senior consultant anesthetist at the time of admission and/or intubation. Primary endpoint was delirium at any time during the ICU stay. Delirium was checked every 8 h by ICU nurses using the intensive care delirium screening checklist (ICDSC), with delirium defined as ICDSC ≥ 4 points. Before evaluation of the ICDSC the Richmond agitation sedation scale (RASS) score and the visual analogue scale for pain (VAS target ≤ 4) were measured. To assure reliable evaluation of the ICDSC, the RASS score of the patient at the time of evaluation had to be ≥ - 2. Assuming an incidence of delirium in the midazolam group of 70 % and in the methohexital group of 35 %, 16 patients were needed each in the midazolam/fentanyl and the methohexital/fentanyl cohorts (p = 0.05, ß = 0.1). Assuming an incidence of delirium in the propofol group of 50 % and in the methohexital group again of 35 %, 94 patients were needed in the propofol/remifentanil and methohexital/remifentanil groups, respectively (p = 0.05, ß = 0.1). RESULTS: A total of 222 patients were evaluated, 34 in the methohexital vs. midazolam group and 188 in the methohexital vs. propofol group. Out of 16 patients sedated with midazolam, 15 developed delirium (94 %) in contrast to only 5 out of 18 patients sedated with methohexital (28 %). Thus compared to midazolam the sedation with methohexital reduced the incidence of delirium by 66 % (p < 0.001) corresponding to a number needed to treat (NNT) of 1.5. Out of 94 patients in the propofol/remifentanil group, 64 developed delirium (68 %) in contrast to only 23 out of 94 in the methohexital/remifentanil group (24 %). Thus compared to propofol the sedation with methohexital reduced the incidence of delirium by 44 % (p < 0.001), corresponding to an NNT of 2.5. CONCLUSION: Sedation with methohexital compared to midazolam or propofol reduced the incidence of delirium by more than 50 % in ventilated ICU patients.

Electronic states of cyclophanes with small bridges.

Electronic absorption and magnetic circular dichroism were recorded for five cyclophanes with ethano bridges: [2.2]paracyclophane, (1,2,4)[2.2.2]cyclophane, (1,2,4;1,2,5)[2.2.2]cyclophane, (1,2,3,4,5,6)(1,2,3,4,5,6)cyclophane, and trans-[2.2]metacyclophane. Spectral and structural analyses were based on geometry optimization and calculations of transition energies, carried out using density functional theory methods. The assignments have been proposed for several electronic transitions observed in the region below 52,000 cm(-1). The observation of transitions which should be forbidden in the high D(2h) symmetry [2.2]paracyclophane suggests a twisted ground state structure of D(2) symmetry, although the former structure with large amplitude vibrations at room temperature cannot be excluded. The PBE0 functional turned out to appropriately reproduce the inter-ring distances and electronic transition energies.

Safety and feasibility of nasopharyngeal evaporative cooling in the emergency department setting in survivors of cardiac arrest.

AIM: Mild therapeutic hypothermia improves survival and neurologic recovery in primary comatose survivors of cardiac arrest. Cooling effectivity, safety and feasibility of nasopharyngeal cooling with the RhinoChill device (BeneChill Inc., San Diego, USA) were determined for induction of therapeutic hypothermia. METHODS: Eleven emergency departments and intensive care units participated in this multi-centre, single-arm descriptive study. Eighty-four patients after successful resuscitation from cardiac arrest were cooled with nasopharyngeal delivery of an evaporative coolant for 1h. Subsequently, temperature was controlled with systemic cooling at 33 degrees C. Cooling rates, adverse events and neurologic outcome at hospital discharge using cerebral performance categories (CPC; CPC 1=normal to CPC 5=dead) were documented. Temperatures are presented as median and the range from the first to the third quartile. RESULTS: Nasopharyngeal cooling for 1h reduced tympanic temperature by median 2.3 (1.6; 3.0) degrees C, core temperature by 1.1 (0.7; 1.5) degrees C. Nasal discoloration occurred during the procedure in 10 (12%) patients, resolved in 9, and was persistent in 1 (1%). Epistaxis was observed in 2 (2%) patients. Periorbital gas emphysema occurred in 1 (1%) patient and resolved spontaneously. Thirty-four of 84 patients (40%) patients survived, 26/34 with favorable neurological outcome (CPC of 1-2) at discharge. CONCLUSIONS: Nasopharyngeal evaporative cooling used for 1h in primary cardiac arrest survivors is feasible and safe at flow rates of 40-50L/min in a hospital setting.

[Successful treatment of extreme metabolic acidosis and profound hypothermia]. / Erfolgreiche Behandlung einer extremen metabolischen Acidose mit ausgeprägter Hypothermie.

A case of extreme metabolic acidosis (pH 6.6) and severe hypothermia (27.3 degrees C) is reported. The patient's anamnesis and medical examination led to the assumption of ketoacidosis. Pronounced ketoacidosis is not unusual in juvenile diabetics type 1 and the incidence in Europe is reported to be between 15 and 70% for all type 1 diabetics. The case describes the targeted therapy of controlled re-warming to avoid neurological damage.

Transcutaneous oximetry in clinical practice: consensus statements from an expert panel based on evidence.

Transcutaneous oximetry (PtcO2) is finding increasing application as a diagnostic tool to assess the peri-wound oxygen tension of wounds, ulcers, and skin flaps. It must be remembered that PtcO2 measures the oxygen partial pressure in adjacent areas of a wound and does not represent the actual partial pressure of oxygen within the wound, which is extremely difficult to perform. To provide clinical practice guidelines, an expert panel was convened with participants drawn from the transcutaneous oximetry workshop held on June 13, 2007, in Maui, Hawaii. Important consensus statements were (a) tissue hypoxia is defined as a PtcO2 <40 mm Hg; (b) in patients without vascular disease, PtcO2 values on the extremity increase to a value >100 mm Hg when breathing 100% oxygen under normobaric pressures; (c) patients with critical limb ischemia (ankle systolic pressure of < or =50 mm Hg or toe systolic pressure of < or =30 mm Hg) breathing air will usually have a PtcO2 <30 mm Hg; (d) low PtcO2 values obtained while breathing normobaric air can be caused by a diffusion barrier; (e) a PtcO2 <40 mm Hg obtained while breathing normobaric air is associated with a reduced likelihood of amputation healing; (f) if the baseline PtcO2 increases <10 mm Hg while breathing 100% normobaric oxygen, this is at least 68% accurate in predicting failure of healing post-amputation; (g) an increase in PtcO2 to >40 mm Hg during normobaric air breathing after revascularization is usually associated with subsequent healing, although the increase in PtcO2 may be delayed; (h) PtcO2 obtained while breathing normobaric air can assist in identifying which patients will not heal spontaneously.

Fentanyl-induced cough does not depend on injection speed: a randomized study.

BACKGROUND: The aim of the study was to investigate whether the incidence of cough after intravenous fentanyl depends on the speed of injection. METHODS: With ethics committee approval, 476 ASA class I-III nonsmoking patients free of bronchial hyperreactivity and respiratory tract infection undergoing general anaesthesia for elective surgery were randomized to either 1.5 microg/kg fentanyl injected over 2, 5 or 10 s or placebo (saline) via a peripheral intravenous cannula. The primary endpoint was the incidence of cough within 5 min after completion of injection. RESULTS: The study was terminated for futility after enrollment of 476 patients because an interim analysis yielded an incidence of cough of 3%, 3% and 6% in the three fentanyl groups, respectively, and of 2% in the placebo group, with no difference between groups (P=0.374, chi(2) test for cough between fentanyl and placebo groups). CONCLUSIONS: Under the conditions of our study, the incidence of cough after 1.5 microg/kg fentanyl injected intravenously over 2, 5 or 10 s was between 3% and 6%, unrelated to the speed of injection and not different from placebo.

[Mobile single-pass batch hemodialysis system in intensive care medicine. Reduction of costs and workload in renal replacement therapy]. / Mobiles Single-pass-batch-Hämodialyse-System in der Intensivmedizin. Reduktion von Kosten und Arbeitsbelastung in der Nierenersatztherapie.

This paper describes the introduction of a single-pass batch hemodialysis system for renal replacement therapy in a 14 bed intensive care unit. The goals were to reduce the workload of intensive care unit physicians using an alternative and simpler method compared to continuous veno-venous hemodiafiltration (CVVHDF) and to reduce the costs of hemofiltrate solutions (80,650 EUR per year in our clinic in 2005). We describe and evaluate the process of implementation of the system as well as the achieved and prospective savings. We conclude that a close cooperation of all participants (physicians, nurses, economists, technicians) of a hospital can achieve substantial benefits for patients and employees as well as reduce the economic burden of a hospital.

Wound oxygen levels during hyperbaric oxygen treatment in healing wounds.

Hyperbaric oxygen (HBO2) increases wound oxygen delivery, but few data quantify wound oxygen levels over the course of healing. We characterized these changes during and after HBO2 treatment in a rat wound model. The treatment group (n=7) received 2.0 ATA HBO2, 90 minutes BID for 15 days. Control rats (n=5) were only exposed to HBO2 during measurement. On days 5, 10, and 15, wound pO2 was measured before, during, and for an hour after HBO2 treatment. Both the peak pO2 and the pO2 one hour after HBO2 treatment were significantly greater than baseline on all days in both the treatment (p < .01) and control group (p < .05). The peak pO2 during HBO2 exposure and one hour after decreased significantly in the treatment group on day 15 compared to day 5 (p <.01, p <.05 respectively). No significant differences were found in pO2 values between days within the control group. These results demonstrate that both the peak wound oxygen levels and duration of elevation change significantly throughout the course of HBO2 treatment.

Left-hemispheric dominance for articulation: a prospective study on acute ischaemic dysarthria at different localizations.

Dysarthria is a frequent symptom in cerebral ischaemia. However, speech characteristics of these patients have not previously been investigated in relation to lesion site in a prospective study. We investigated the auditory perceptual features in 62 consecutive patients with dysarthria due to a single, non-space-occupying cerebral infarction confirmed by MRI. Standardized speech samples of all patients were stored within 72 h after stroke onset using a digital tape recorder. Speech samples were assessed independently by two experienced speech therapists, who were unaware of the clinical and neuroradiological findings, using an interval scale ranging from 0 to 6. Separately assessed were features of articulation, phonation, prosody, and the global severity for a total of 31 items. Extracerebellar infarctions (85.5%) were located in the lower motor cortex (14.5%), striatocapsular region (46.8%) and base of the pons (24.2%). Isolated cerebellar infarctions were present in 14.5% of patients. There was a strong correlation between the findings of both examiners, showing identical scores, or only minor differences (<1 on the assessment scale) for 80% of all items. The average severity of dysarthria was 2.9 +/- 1.3. Articulatory abnormalities were the predominant deviation characteristics, affecting in particular the production of consonants. However, phonatory and prosodic abnormalities were also frequently observed speech characteristics. As revealed by factor analysis of speech characteristics the total severity of dysarthria was mainly influenced by the impairment of articulation. Speech parameters describing characteristics of articulation and prosody showed significant side-to-side and area differences, while this effect was lacking for any voice parameter. Left cerebral lesions showed a more severe overall impairment of speech and articulation, independent of lesion topography. Thirty-eight of 62 patients were available for follow-up. Speech evaluation showed normal speech within weeks in 15 out of 38 patients (39.5%). In the other 23 patients overall severity of dysarthria was mild. This is the first prospective study which describes speech characteristics of dysarthria due to acute unilateral cerebral infarctions. We could demonstrate that dysarthria in extracerebellar infarctions was more frequently caused by left-sided lesions and that the severity of dysarthria was more pronounced in left-sided lesions independent from lesion topography. All extracerebellar lesions were located along the course of the cortico-bulbar tract fibres. Compatible with a common pathophysiological basis of dysarthria in these patients, none of the 31 speech items differed significantly between subcortical and brainstem lesions.

UHMS position statement: topical oxygen for chronic wounds.

A small body of literature has been published reporting the application of topical oxygen for chronic non-healing wounds . Frequently, and erroneously, this form of oxygen administration has been referred to as "topical hyperbaric oxygen therapy" or even more erroneously "hyperbaric oxygen therapy." The advocates of topical oxygen claim several advantages over systemic hyperbaric oxygen including decreased cost, increased safety, decreased complications and putative physiologic effects including decreased free radical formation and more efficient delivery of oxygen to the wound surface. With topical oxygen an airtight chamber or polyethylene bag is sealed around a limb or the trunk by either a constriction/tourniquet device or by tape and high flow (usually 10 liters per minute) oxygen is introduced into the bag and over the wound. Pressures just over 1.0 atmospheres absolute (atm abs) (typically 1.004 to 1.013 atm abs) are recommended because higher pressures could decrease arterial/capillary inflow. The premise for topical oxygen, the diffusion of oxygen into the wound adequate to enhance healing, is attractive (though not proven) and its delivery is certainly less complex and expensive than hyperbaric oxygen. When discussing the physiology of topical oxygen, its proponents frequently reference studies of systemic hyperbaric oxygen suggesting that mechanisms are equally applicable to both topical and systemic high pressure oxygen delivery. In fact, however, the two are very different. To date, mechanisms of action whereby topical oxygen might be effective have not been defined or substantiated. Conversely, cellular toxicities due to extended courses of topical oxygen have been reported, although, again these data are not conclusive, and no mechanism for toxicity has been examined scientifically. Generally, collagen production and fibroblast proliferation are considered evidence of improved healing, and these are both enhanced by hyperbaric oxygen therapy. Paradoxically, claims of decreased collagen production and fibroblast inhibition in wounds subjected to topical oxygen have been reported in studies of topical oxygen as a benefit of topical oxygen therapy. The literature on topical oxygen is mostly small case series or small controlled but not randomized trials. Moreover, the studies generally are not aimed at specific ulcer types, but rather at "chronic wounds." This non-specific approach is recognized as a major design flaw in any study of therapies designed to improve impaired wound healing. The only randomized trial for topical oxygen in diabetic foot ulcers actually showed a tendency toward impaired wound healing in the topical oxygen group. Contentions that topical oxygen is superior to hyperbaric oxygen are not proven. There are potentially plausible mechanisms that support both possibly beneficial and detrimental effects of topical oxygen therapy, and thus well designed and executed basic science research and clinical trials are clearly needed. There is some ongoing research in regard to the role of topical oxygen at established wound laboratories. Neither CMS nor other third party payors recognize or reimburse for topical oxygen. Therefore, the policy of the Undersea and Hyperbaric Medical Society in regard to topical oxygen is stated as follows: 1. Topical oxygen should not be termed hyperbaric oxygen since doing so either intentionally or unintentionally suggests that topical oxygen treatment is equivalent or even identical to hyperbaric oxygen. Published documents reporting experience with topical oxygen should clearly state that topical oxygen not hyperbaric oxygen is being employed. 2. Mechanisms of action or clinical study results for hyperbaric oxygen cannot and should not be co-opted to support topical oxygen since hyperbaric oxygen therapy and topical oxygen have different routes and probably efficiencies of entry into the wound and their physiology and biochemistry are necessarily different. 3. The application of topical oxygen cannot be recommended outside of a clinical trial at this time based on the volume and quality of scientific supporting evidence available, nor does the Society recommend third party payor reimbursement. 4. Before topical oxygen can be recommended as therapy for non-healing wounds, its application should be subjected to the same intense scientific scrutiny to which systemic hyperbaric oxygen has been held.

[Successful resuscitation of a patient with hyperkalemic cardiac arrest by emergency hemodiafiltration]. / Erfolgreiche Reanimation einer Patientin mit hyperkaliämischem Herzstillstand durch notfallmässige Hämodiafiltration.

The combination of spironolactone with an ACE inhibitor for patients with heart failure may cause severe hyperkalemia. We report the case of a female patient, who developed hyperkalemic (11.4 mmol/l) cardiac arrest probably induced by combined spironolactone and ACE-inhibitor therapy. She was treated successfully by hemodiafiltration under on-going resuscitation which resulted in restoration of spontaneous circulation within 30 min of starting CPR. She was discharged 2 weeks later without any residual neurological effects.

[Familial cavernous malformations of the central nervous system. A clinical and genetic study of 15 German families]. / Familiäre Kavernome des Zentralnervensystems. Eine klinische und genetische Studie an 15 deutsche Familien.

In 1928, Hugo Friedrich Kufs reported on a family with cerebral, retinal, and cutaneous cavernous malformations. Since then, more than 300 families with inherited cavernous malformations have been reported. Genetic studies showed three loci, on chromosomes 7q21-q22 (with the gene CCM1), 7p15-p13 (CCM2), and 3q25.2-q27 (CCM3). The gene product of CCM1 is Krit 1 (Krev interaction trapped 1), a protein interacting with angiogenesis by various mechanisms. Recently, CCM2 has also been identified; its product is a protein which might have a function similar to that of Krit 1. However, the CCM3 gene has still not been found. In this study, we present clinical and genetic findings on 15 German families.

[A factorial trial of six interventions for the prevention of postoperative nausea and vomiting]. / Eine faktorielle Studie von 6 Interventionen zur Vermeidung von Ubelkeit und Erbrechen nach Narkosen Ergebnisse des "International Multicenter Protocol to assess the single and combined benefits of antiemetic strategies in a controlled clinical trial of a 2x2x2x2x2x2 factorial design" (IMPACT).

BACKGROUND: Untreated, one third of patients who undergo surgery will have postoperative nausea and vomiting. Although many trials have been conducted, the relative benefits of prophylactic antiemetic interventions given alone or in combination remain unknown. METHODS: In a randomized, controlled trial of factorial design, 5,199 patients at high risk for postoperative nausea and vomiting were randomly assigned to 1 of 64 possible combinations of 6 prophylactic interventions: 1) 4 mg of ondansetron or no ondansetron; 2) 4 mg of dexamethasone or no dexamethasone; 3) 1.25 mg of droperidol or no droperidol; 4) propofol or a volatile anesthetic; 5) nitrogen or nitrous oxide; 6) remifentanil or fentanyl. The primary aim parameter was nausea and vomiting within 24 h after surgery, which was evaluated blindly. RESULTS: Ondansetron, dexamethasone, and droperidol each reduced the risk of postoperative nausea and vomiting by about 26%, propofol reduced the risk by 19%, and nitrogen by 12%. The risk reduction with both of these agents (i.e., total intravenous anesthesia) was thus similar to that observed with each of the antiemetics alone. All the interventions acted independently of each other and independently of the patients' baseline risk. Consequently, the relative risks associated with the combined interventions could be estimated by multiplying the relative risks associated with each intervention. However, absolute risk reduction was a critical function of patients' baseline risk. CONCLUSIONS: Because antiemetic interventions are similarly effective and act independently, the safest or least expensive should be used first. Prophylaxis is rarely warranted in low-risk patients, moderate-risk patients may benefit from a single intervention, and multiple interventions should be reserved for high-risk patients.

A topodiagnostic investigation on body lateropulsion in medullary infarcts.

Body lateropulsion may occur without signs of vestibular dysfunction and vestibular nucleus involvement. The authors examined 10 such patients with three-dimensional brainstem mapping. Body lateropulsion without limb ataxia reflected an impairment of vestibulospinal postural control caused by a lesion of the descending lateral vestibulospinal tract, whereas body lateropulsion with limb ataxia was probably the consequence of impaired or absent proprioceptive information caused by a lesion of the ascending dorsal spino-cerebellar tract.

[Are peripheral nerve blocks of the leg (femoralis in combination with anterior sciatic blockade) as sole anaesthetic technique an alternative to epidural anaesthesia]. / Ist die periphere Nervenblockade des Beines (Femoralis- in Kombination mit anteriorer Ischiadikusblockade) als alleinige Anästhesietechnik eine Alternative zur Periduralanästhesie für arthroskopische Eingriffe am Kniegelenk?

OBJECTIVE: We compared peripheral nerve blocks (PNB, femoral nerve block together with anterior sciatic nerve block) as sole anaesthetic with epidural anaesthesia (EA) in a randomised study in patients undergoing elective arthroscopic knee surgery with respect to patient satisfaction and time required to perform each procedure. METHODS: 99 ASA class I-III patients were randomised to either PNB (20 ml bupivacaine 0.5 % + 60 ml prilocaine 1 %) or EA (12 - 20 ml bupivacaine 0.5 %). ENDPOINTS: patient satisfaction with the anaesthetic evaluated by a questionnaire 3 months after the operation, anaesthesia and surgical times, need for additional analgesics and the modified Aldrete-score (global assessment of postanaesthetic condition) at admission in the postanaesthesia care unit. RESULTS: Significantly more patients in the PNB compared to the EA group needed intravenous opioid supplementation (10 vs. 3, p = 0.040). While the patients in the PNB group had a significantly higher modified Aldrete score (9.3 +/- 0.7 vs. 8.8 +/- 0.9, p = 0.0009), assessment (0 = worst, 10 = best) of the induction of PNB or EA respectively, was significantly better rated in the EA compared to PNB group (8.7 +/- 2.1 vs. 6.7 +/- 2.6, p = 0.0024). Assuming that the willingness to undergo the same anaesthetic again reflect overall satisfaction with the procedure satisfaction in both groups was high: 25/26 (PNB) and 27/28 (EA) would have preferred their regional blockade (p = 0.95). CONCLUSION: Patients in the PNB and EA group both were satisfied with their anaesthetic procedure. While there are obviously differences in favour of the EA, PNB is an alternative in the case of contraindication or patient rejection to EA.

Brainstem reflex circuits revisited.

Our current understanding of brainstem reflex physiology comes chiefly from the classic anatomical-functional correlation studies that traced the central circuits underlying brainstem reflexes and establishing reflex abnormalities as markers for specific areas of lesion. These studies nevertheless had the disadvantage of deriving from post-mortem findings in only a few patients. We developed a voxel-based model of the human brainstem designed to import and normalize MRIs, select groups of patients with or without a given dysfunction, compare their MRIs statistically, and construct three-plane maps showing the statistical probability of lesion. Using this method, we studied 180 patients with focal brainstem infarction. All subjects underwent a dedicated MRI study of the brainstem and the whole series of brainstem tests currently used in clinical neurophysiology: early (R1) and late (R2) blink reflex, early (SP1) and late (SP2) masseter inhibitory reflex, and the jaw jerk to chin tapping. Significance levels were highest for R1, SP1 and R2 afferent abnormalities. Patients with abnormalities in all three reflexes had lesions involving the primary sensory neurons in the ventral pons, before the afferents directed to the respective reflex circuits diverge. Patients with an isolated abnormality of R1 and SP1 responses had lesions that involved the ipsilateral dorsal pons, near the fourth ventricle floor, and lay close to each other. The area with the highest probabilities of lesion for the R2-afferent abnormality was in the ipsilateral dorsal-lateral medulla at the inferior olive level. SP2 abnormalities reached a low level of significance, in the same region as R2. Only few patients had a crossed-type abnormality of SP1, SP2 or R2; that of SP1 reached significance in the median pontine tegmentum rostral to the main trigeminal nucleus. Although abnormal in 38 patients, the jaw jerk appeared to have no cluster location. Because our voxel-based model quantitatively compares lesions in patients with or without a given reflex abnormality, it minimizes the risk that the significant areas depict vascular territories rather than common spots within the territory housing the reflex circuit. By analysing statistical data for a large cohort of patients, it also identifies the most frequent lesion location for each response. The finding of multireflex abnormalities reflects damage of the primary afferent neurons; hence it provides no evidence of an intra-axial lesion. The jaw jerk, perhaps the brainstem reflex most widely used in clinical neurophysiology, had no apparent topodiagnostic value, probably because it depends strongly on peripheral variables, including dental occlusion.