[Rudolf Frey - a biographical sketch on the occasion of his 100th birthday]. / Rudolf Frey ­ eine biografische Skizze aus Anlass seines 100. Geburtstags.

The life of an outstanding human being, a creative personality, will find the interest of posterity if he is acknowledged not only as a representative of his time but also decades later can be described as a formative character. This applies to Rudolf Frey who, like no other, has deeply influenced the development of German language anesthesiology after the Second World War. In the 1950s and 1960s as a visionary he already portrayed the four pillars of our discipline as the future field of work of anesthetists: anesthesiology, intensive care, emergency medicine and pain therapy. The authors take the anniversary of his 100th birthday as an occasion to recall Rudolf Frey's extraordinary biography.

[Subdural hematoma after dural puncture: fateful complication of epidural anesthesia]. / Subdurales Hämatom nach Duraperforation: Schicksalhafte Komplikation der Periduralanästhesie.

Subdural hematoma may occur as rare, although intervention- specific complications of accidental dural puncture by neuroaxial block. Bleeding may be caused by rapid cerebrospinal fluid loss related to traction on fragile intracranial bridging veins. This article reports a case of postdural puncture headache in a 43-year-old woman after accidental dural puncture during attempted placement of an epidural catheter for induction of abortion. Bed rest, analgesics, theophylline and hydration were to no avail and only a blood patch improved the headaches. The patient presented 7 weeks later with headache and left-sided hemiplegia. Magnetic resonance imaging showed a right frontoparietal subdural intracranial hematoma which had to be surgically evacuated. The patient recovered completely. Intracranial hematoma is a rare but serious complication of central neuroaxial block. According to current German jurisdiction this risk must be addressed when informed consent is obtained. Intracranial hematoma should be considered in the differential diagnosis of atypical headache and neurological signs (e.g. focal motor and sensory deficits and seizures) following neuroaxial block and adequate image diagnostics should be carried out without delay.

[Postpartum eclampsia and fulminant HELLP syndrome]. / Postpartale Eklampsie und fulminantes HELLP-Syndrom.

Postpartum onset of eclampsia and HELLP (hemolysis, elevated liver enzymes, low platelet count) syndrome is a rare but life-threatening complication for both mother and fetus. A case of a 38-year-old parturient (gravida 2, para 1) who was asymptomatic prior to delivery is reported. Emergency caesarean section had to be performed due to sudden onset of fetal bradycardia as a result of partial placental separation. The perioperative course was characterized by new onset hypertension, nausea and restlessness; within 2 h the patient suffered a generalized seizure which was treated with magnesium sulfate and hydralazine. Despite management in accordance with current guidelines, the condition deteriorated with hypotension, anemia and renal failure. On further examination hematomas in the abdominal cavity and walls were identified and laboratory tests confirmed HELLP syndrome with severe coagulopathy. Explorative laparotomy revealed diffuse bleeding without a significant isolated source or postpartum uterine hemorrhage. Retrospectively, the anemia could be ascribed to severe hemolysis and diffuse bleeding from coagulopathy. The patient required packed red cells, platelets, fresh frozen plasma and prothrombin complex. After admission to the intensive care unit persistent diffuse bleeding mainly caused by hyperfibrinolysis and renal failure occurred, which required blood transfusion, antifibrinolytic (tranexamic acid) and renal replacement therapy (continuous veno-venous hemodiafiltration with citrate) for 6 days. The patient recovered without any sequelae and was discharged 26 days later. Placental separation with new onset peripartum hypertension is to be interpreted as a precursor of severe gestosis and associated complications, especially disseminated intravascular coagulation (DIC), acute renal failure and pleural effusion. A differentiation between a rapid drop in hemoglobin concentration secondary to hemolysis in postpartum HELLP syndrome rather than postpartum hemorrhage can be challenging. In addition, HELLP syndrome can lead to rapidly developing, fulminant hyperfibrinolysis in the context of DIC. Keys to successful management of postpartum gestosis and associated complications are early detection and perception of clinical and laboratory warning signs, a multidisciplinary approach with rapid and consistent targeted symptomatic therapy to save the mother and fetus.

Effects of fenoldopam on intracranial pressure and hemodynamic variables at normal and elevated intracranial pressure in anesthetized pigs.

Fenoldopam (FE), a dopamine DA1-receptor agonist, has been introduced for treatment of arterial hypertension and heart failure and for preservation of renal function. Vasodilators are generally assumed to affect all vascular beds including the cerebral circulation. We have evaluated effects of FE-induced (4 micrograms.kg-1.min-1) arterial hypotension on intracranial pressure (ICP) and intraocular pressure (IOP) under conditions of normal and increased intracranial elastance. ICP and IOP responses to hypertension were tested by infusion of angiotensin II (15 micrograms.kg-1.min-1), and the response to hypercapnia was tested by elimination and reintegration of soda lime canisters in the breathing circuit. Intracranial elastance was increased by infusing mock cerebrospinal fluid (CSF) into the lateral ventricle (20 +/- 3 ml.h-1). Arterial hypotension induced with FE did not increase ICP. With increased intracranial elastance, the infusion rate of mock CSF had to be reduced while administering FE to avoid a rise in ICP (p < 0.05 compared with preinfusion value); this indicates a shift on the volume-pressure curve to the right. There were no indicators that cerebral autoregulation or CO2 reactivity of the cerebral vasculature were affected by FE in this anesthetized porcine model, as speculated from analysis of the time course of delta ICP. There are, however, indicators of increased intracranial elastance, most likely caused by vasodilation. Caution should hence be exercised when FE is administered to patients with increased intracranial elastance.

Local brain surface temperature compared to temperatures measured at standard extracranial monitoring sites during posterior fossa surgery.

Mild hypothermia is assumed to protect against secondary brain injury. However, the accuracy of brain temperature estimation remains debatable if direct measurement in the target area is to be avoided or is impossible. Furthermore, intracerebral temperature gradients exist, especially under intraoperative conditions. We aimed to establish how brain surface temperatures (TBrain) relate to temperatures taken at standard sites in posterior fossa surgery. Ten patients undergoing cerebellopontine angle tumor removal were monitored for TBrain, esophageal temperature (TEso), bladder temperature (TBlad), ipsi- and contralateral tympanic membrane (TTymp-I, TTymp-C), and scalp temperatures (TScalp). During monitoring, TEso increased from 35.3+/-0.2 degrees C to 36.0+/-0.3 degrees C. After dura opening, TBrain was -0.14+/-0.1 degrees C below TEso. At the end of tumor removal, this difference increased to -0.43+/-0.31 degrees C (P < 0.05). TTymp-C was -0.29+/-0.18 degrees C below TBrain at dura opening. TTymp-C reflected the behavior of TEso adequately (r = 0.938), however, with a mean difference of -0.39+/-0.04 degrees C. In contrast, TTymp-I readings closely followed temperature changes in the area of surgery. TBlad reflected TEso except in periods of rapid temperature changes. In posterior fossa (PF) surgery, local TBrain is most accurately reflected by TEso. For clinical use TBlad and TTymp-C are also sufficient to assess brain surface temperature in the PF. Intraoperative surface cooling of the brainstem is less than the previously described cooling rate of exposed cerebral cortex.

Heated breathing tubes affect humidity output of circle absorber systems.

STUDY OBJECTIVE: To verify whether the airway climate in circle systems can be improved with heated breathing tubes. DESIGN: Randomized, controlled, prospective clinical study. SETTING: Operating theater of the Department of Maxillofacial Surgery. PATIENTS: 26 adult patients undergoing prolonged anesthesia. INTERVENTIONS: A total of 26 prolonged anesthetics were conducted in adult patients using a minimal fresh gas flow rate (0.6 L/min) and silicon breathing tubes (16 mm internal diameter) containing a heated coil. Group 1 (n = 10 patients) was the control group; breathing tubes were unheated. In Group 2 (n = 10 patients), breathing tubes were heated to 30 degrees C. In Group 3 (n = 6 patients), breathing tubes were heated to 36 degrees C. MEASUREMENTS AND MAIN RESULTS: Humidity and temperature were measured at the Y-piece. Inspiratory temperature on Group 2 was significantly higher than in Group 1. In Group 3, both inspiratory temperature and absolute humidity were significantly higher than in Group 1. After 5 minutes of ventilation, water content and temperature of inspiratory gases were significantly higher in Group 3 than in Group 1. CONCLUSION: Low-flow systems need at least 120 minutes to achieve a satisfactory airway climate. Heated breathing tubes effectively reduce this delay.

Does fresh gas flow rate affect monitoring requirements?

Opinions vary on the monitoring requirements associated with low flow to closed circuit anesthesia. Fresh gas flow rate affects variables of anesthesia ventilation such as the time constant of the breathing system, the inspired concentrations of O2, N2O and anesthetic vapor and the potential for rebreathing. Furthermore, very low flow rates challenge the performance of rotameters and vaporizers. Consequently, the safe conduct of minimal flow or closed circuit anesthesia mandates oximetry, which should be redundant; the use of anesthetic agent monitors ("anesthetico-meters") is extremely helpful, and so is capnometry. However, none of these safety monitors is beyond the scope of the "essential requirements" proposed for anesthesia workstations by international standard-writing groups, such as CEN or ISO. It may hence be concluded that fresh gas flow rate does affect variables to be monitored, but it does not affect essential monitoring requirements.

Malignant hyperthermia susceptibility--successful management with a "stressfree" technique.

The pathogenesis of the malignant hyperthermia syndrome is not yet completely understood. There is evidence of involvement of the sympathoadrenergic system. We describe the anesthetic management of two patients considered to be MH-susceptible. Management in the theater included an infusion of dantrolene 2.5 mg/kg prior to induction of anesthesia. In addition, the first patient was given a peroral prophylaxis with dantrolene; in subsequent cases this route of administration was abandoned. Anesthesia was performed with a drug combination devoid of sympathomimetic effects (diazepam, flunitrazepam, midazolam,--methohexital,--fentanyl, alfentanil,--vecuronium). Monitoring should include ECG, blood pressure, body temperature and end-tidal CO2-concentration.

Cardiovascular effects produced by a combination of d-tubocurarine and pancuronium in dogs.

The effect on the cardiovascular system of a combination of pancuronium (0.048 mg/kg) and d-tubocurarine (0.288 mg/kg) was studied in five conditioned dogs anesthetized with fentanyl. Changes in heart rate, mean arterial pressure, central venous pressure, mean pulmonary artery pressure, pulmonary capillary wedge pressure, stroke volume, cardiac output, systemic vascular resistance and pulmonary vascular resistance were recorded 2, 5, 10, 20, 30, 40 and 50 minutes after administration of the drug combination. Arterial blood samples were assayed for estimation of histamine levels. There was a significant fall in central venous pressure and mean arterial pressure at 2 minutes (p less than 0.05) and a significant rise in heart rate at 2 and 5 minutes (p less than 0.05). These changes were not significant at 10 minutes. There was no significant change in the other parameters measured and no significant release of histamine. It is concluded that the smaller doses of pancuronium and d-tubocurarine used in combination in dogs do not completely attenuate the cardiovascular effects of either drug when used independently, but that the changes are transient and no longer significant at 10 minutes.

[Unclear altered mental state and respiratory insufficiency following multiple injuries: fat embolism syndrome]. / Unklare Vigilanzstörung und respiratorische Insuffizienz nach Mehrfachverletzung: Fettemboliesyndrom.

Fat embolism syndrome is associated with respiratory failure, hypoxia, petechial rash, pyrexia and altered mental state. Signs and symptoms usually begin within 12-72 h after trauma. The pathophysiology, differential diagnosis and therapeutic options of fat embolism syndrome are described and the case of a 29-year-old motorcyclist with fractures of the lower extremities, coma and respiratory failure 24-36 h after an accident is reported. Based on the clinical signs and course, fat embolism syndrome was suspected which was substantiated by ophthalmic fundoscopy and magnetic resonance imaging of the head.

[Anesthesia and intraocular pressure]. / Anaesthesie und intraokularer Druck.

General anesthesia has been in use for ophthalmic surgery since 1847. The subsequent predominance of local anesthetic techniques made ophthalmic anesthesia the "Cinderella of anesthesia services" until its clinical and scientific rehabilitation in the second half of this century. Precise control of intraocular tension is an accepted advantage of general anesthesia. The exercise of such control requires understanding of intraocular physiology and the effects exerted by anesthetic techniques. Hence, the impact of anesthetic drugs on intraocular pressure (IOP) must be considered when ophthalmic surgery is to be carried out under general anesthesia. Intravenous anesthetics and volatile agents reduce IOP, with the possible exception of ketamine. Underlying mechanisms include a direct effect on cerebral IOP control centers and indirect effects mediated through the balance between production and drainage of aqueous humor, general circulation and ocular muscle tone. IOP is likely to be elevated during induction and recovery. Currently suggested measures to prevent the increase in IOP associated with laryngoscopic tracheal intubation facilitated by succinylcholine include oral premedication with clonidine, intravenous administration of lidocaine 3 min prior to laryngoscopy, and anesthetic induction with propofol or narcotics. Non depolarizing neuromuscular blocking drugs either do not affect IOP or produce a slight decrease; depolarizing muscle relaxants increase IOP. It remains controversial whether this effect, which is pronounced with succinylcholine, may be reliably abolished by any concomitant medication. The new competitive relaxants atracurium and vecuronium provide stable conditions with respect to IOP and systemic circulation, combined with a rapid onset and intermediate duration of action.