[Treatment of extreme anemia with polymerized bovine hemoglobin : Case report and review of the literature]. / Therapie einer extremen Anämie mit vernetztem Rinderhämoglobin : Fallbericht mit Literaturüberblick.

This article reports the case of a 29-year-old female Jehovah's Witness with severe anemia after intrauterine fetal death in the 25th week of gestation, complicated by vaginal bleeding, acute renal failure and hemolysis. Due to her religious beliefs the patient categorically refused blood transfusions. Despite adhering to the recommendations for patient blood management, the hemoglobin (Hb) level gradually decreased to 1.9 g/dl on day 10, when she fainted and had to be sedated and invasively ventilated. Inhalative isoflurane was chosen for sedation because of its potential organ-protective effects and because it provides deep sedation with reduced oxygen requirements, while enabling rapid neurological examination during the sedation windows as well as regular and calm spontaneous breathing. Posthypoxic encephalopathy was demonstrated clinically and electroencephalographically by seizure activity during the sedation windows. Anticonvulsive treatment was started. At a hemoglobin of 1.8 g/dl, she received 2 units of polymerized bovine hemoglobin (Hemopure®, Hemoglogin Oxygen Therapeutics LLC, Souderton, PA, USA), repeated several times on subsequent days because of its short half-life. Considerable methemoglobinemia was noted. After subtracting methemoglobin, the hemoglobin rose by 0.4-0.8 g/dl after each 2 units, initially increasing the oxygen binding capacity of the blood by 33%. After a full neurological recovery and weaning from the ventilator but still on hemodialysis, the patient was transferred to another hospital after 38 days.If allogeneic blood transfusion is not an option, administration of polymerized bovine hemoglobin can temporarily increase the oxygen transport capacity as a last resort treatment. Reduction of oxygen requirements by deep inhaled sedation with isoflurane also seems beneficial and provides advantages.

[New technical developments for inhaled sedation]. / Neue technische Entwicklungen der inhalativen Sedierung.

The circle system has been in use for more than 100 years, whereas the first clinical application of an anaesthetic reflector was reported just 15 years ago. In the circle system, all breathing gas is rebreathed after carbon dioxide absorption. A reflector, on the other hand, with the breathing gas flowing to and fro, specifically retains the anaesthetic during expiration and resupplies it during the next inspiration. A high reflection efficiency (number of molecules resupplied/number of molecules exhaled, RE 80-90%) decreases consumption. In analogy to the fresh gas flow of a circle system, pulmonary clearance ((1-RE) × minute ventilation) defines the opposition between consumption and control of the concentration.It was not until reflection systems became available that volatile anaesthetics were used routinely in some intensive care units. Their advantages, such as easy handling, and better ventilatory capabilities of intensive care versus anaesthesia ventilators, were basic preconditions for this. Apart from AnaConDa™ (Sedana Medical, Uppsala, Sweden), the new MIRUS™ system (Pall Medical, Dreieich, Germany) represents a second, more sophisticated commercially available system.Organ protective effects, excellent control of sedation, and dose-dependent deep sedation while preserving spontaneous breathing with hardly any accumulation or induction of tolerance, make volatile anaesthetics an interesting alternative, especially for patients needing deep sedation or when intravenous drugs are no longer efficacious.But obviously, the outcome is most important. We know that deep intravenous sedation increases mortality, whereas inhalational sedation could prove beneficial. We now need prospective clinical trials examining mortality, but also the psychological outcome of those most critically ill patients sedated by inhalation or intravenously.

A novel device for target controlled administration and reflection of desflurane--the Mirus™.

The Anaconda™ system is used to deliver inhalational sedation in the intensive care unit in mainland Europe. The new Mirus™ system also uses a reflector like the Anaconda; however, it also identifies end-tidal concentrations from the gas flow, injects anaesthetics during early inspiration, controls anaesthetic concentrations automatically, and can be used with desflurane, which is not possible using the Anaconda. We tested the Mirus with desflurane in the laboratory. Compared with an external gas monitor, the bias (two standard deviations) of the end-tidal concentration was 0.11 (0.29)% volume. In addition, automatic control was reasonable and maximum concentration delivered was 10.2%, which was deemed to be sufficient for clinical use. Efficiency was > 80% and was also deemed to be acceptable, but only when delivering a low concentration of desflurane (≤ 1.8%). By modifying the reflector, we improved efficiency up to a concentration of 3.6%. The Mirus appears to be a promising new device for long-term sedation with desflurane on the intensive care unit, but efficiency must be improved before routine clinical use becomes affordable.

Graft-versus-host disease or toxic epidermal necrolysis: diagnostic dilemma after liver transplantation.

Graft-versus-host disease (GvHD) and toxic epidermal necrolysis (TEN) are rare and severe complications after liver transplantation. While mild acute GvHD is quite different from TEN and easy to distinguish, severe acute GvHD and TEN can be hard to differentiate because of similar clinical symptoms. We herein report a case with rapid progression of critical illness, after liver transplantation, caused by GvHD or TEN, although between those, diagnosis was not possible during the clinical course. Although, based on the timing/progression of the symptoms and the chimerism of >40%, the case seemed much more clinically consistent with GVHD, the combination of clinical symptoms together with skin rashes and the histologic appearance of skin lesions indicated diagnosis of a Stevens-Johnson syndrome/TEN overlap. The true diagnostic dilemma in such cases is discussed in detail, as these cases emphasize the need for more advanced diagnostic techniques.

[Functioning of the anaesthetic conserving device: aspects to consider for use in inhalational sedation]. / Funktionsweise des "Anaesthetic Conserving Device" : Besonderheiten beim Einsatz zur inhalativen Sedierung.

The new anaesthetic conserving device (ACD) allows the use of isoflurane and sevoflurane without classical anaesthesia workstations. Volatile anaesthetic exhaled by the patient is absorbed by a reflector and released to the patient during the next inspiration. Liquid anaesthetic is delivered via a syringe pump. Currently the use of the ACD is spreading among European intensive care units (ICU). This article focuses on the functioning of the device and on particularities which are important to consider. The ACD constantly reflects 90% of the exhaled anaesthetic back to the patient, but if one exhaled breath contains more than 10 ml of anaesthetic vapour (e.g. >1 vol% in 1,000 ml), the capacity of the reflector will be exceeded and relatively more anaesthetic will be lost to the patient. This spill over decreases efficiency but it also contributes to safety as very high concentrations are averted. Compared to classical anaesthesia systems the ACD used in conjunction with ICU ventilators offers advantages in the ICU setting: investment costs are low, carbon dioxide absorbent is not needed, breathing comfort is higher, anaesthetic consumption is low (equal to an anaesthesia circuit with a fresh gas flow of approximately 1 l/min) and anaesthetic concentrations can be controlled very quickly (increased by small boluses and decreased by removal of the ACD). On the other hand, case costs are higher (single patient use) and a dead space of 100 ml is added. There are pitfalls: by a process called auto-pumping, expansion of bubbles inside the syringe may lead to uncontrolled anaesthetic delivery. Auto-pumping is provoked by high positioning of the syringe pump, heat and prior cooling of the liquid anaesthetic. Inherent to the device is an early inspiratory concentration peak and an end-inspiratory dip which may mislead commonly used gas monitors. Workplace concentrations can be minimized by proper handling, a sufficient turnover of room air is important and gas from the expiration port of the ventilator should be scavenged. Inhalational compared to intravenous ICU sedation offers the advantages of better control of the sedation level, online drug monitoring, no accumulation in patients with renal or hepatic insufficiency and bronchodilation. With a lowered opioid dose spontaneous breathing and intestinal motility are well preserved. A clinical algorithm for the care of patients with respiratory insufficiency including inhalational sedation is proposed. Inhalational sedation with isoflurane has been widely used for more than 20 years in many countries and even for periods of up to several weeks. In the German S3 guidelines for the management of analgesia, sedation and delirium in intensive care (Martin et al. 2010), inhalational sedation is mentioned as an alternative sedation method for patients ventilated via an endotracheal tube or a tracheal cannula. Nevertheless, isoflurane is not officially licensed for ICU sedation and its use is under the responsibility of the prescribing physician.

[Symptomatic epidural haematoma under therapeutic dose heparin: occurrence after removal of a peridural catheter]. / Symptomatisches epidurales Hämatom unter therapeutischer Heparinisierung: Auftreten nach Entfernung eines Periduralkatheters.

A 55-year-old patient with severe arterial occlusive disease underwent a femoral artery bypass operation under combined spinal-epidural anaesthesia. Platelet count and coagulation tests were normal after phenprocoumon had been discontinued. The epidural catheter was removed on day 1 while the patient was under therapeutic dose heparin. On day 2 he complained about lower back pain going down both legs and tendon reflexes were absent on the left side. Computed tomography and magnetic resonance imaging showed a lumbar epidural haematoma, which together with a previously existing protrusion of the fourth lumbar disc, compressed the cauda equina. A neurosurgical consultation recommended a conservative approach. The symptoms resolved spontaneously and the patient was discharged in good condition 12 days after the operation.

[Limited, haemoglobin-dependent indication for autologous blood donation in total hip or knee replacement]. / Eingeschränkte, Hämoglobin-abhängige Indikation zum Eigenblutverfahren bei Endoprothesenimplantation des Hüft- oder Kniegelenkes.

AIM: The rejection rate of autologous blood donation before joint replacement is high. The influence of the haemoglobin value and the age of patient before autologous blood donation was examined according to the necessity for blood transfusion. METHOD: In a retrospective study, the data of 233 patients who had donated autologous blood before hip (THR) or knee arthroplasty (TKR) were analysed. RESULTS: 72 patients (30.9 %) received an autologous blood transfusion during surgery or in the further course until the first day after surgery. A multivariate analysis showed no significant influence of age on the need for transfusions (p = 0.093), but a higher haemoglobin value before blood donation reduced the risk significantly to 0.712 per unit (1 g/dl). Therefore the age of the patient was less predictive compared to the haemoglobin value as to whether or not a blood transfusion had been necessary. CONCLUSION: The high security of homologous blood reached in the last years and the knowledge that autologous blood donation reduces the haemoglobin value before surgery has led to the procedure in our hospital only to perform autologous blood donation at the explicit request of the patient.

Desflurane compared with propofol for postoperative sedation in the intensive care unit.

BACKGROUND: We hypothesized that emergence from sedation in postoperative patients in the intensive care unit would be faster and more predictable after sedation with desflurane than with propofol. METHODS: Sixty patients after major operations were allocated randomly to receive either desflurane or propofol. The target level of sedation was defined by a bispectral index(TM) (BIS(TM)) of 60. All patients were receiving mechanical ventilation of the lungs for 10.6 (SD 5.5) h depending on their clinical state. The study drugs were stopped abruptly in a calm atmosphere with the fresh gas flow set to 6 litres min(-1), and the time until the BIS increased above 75 was measured (t(BIS75), the main objective measure). After extubation of the trachea, when the patients could state their birth date, they were asked to memorize five words. RESULTS: Emergence times were shorter (P<0.001) after desflurane than after propofol (25th, 50th and 75th percentiles): t(BIS75), 3.0, 4.5 and 5.8 vs 5.2, 7.7 and 10.3 min; time to first response, 3.7, 5.0 and 5.7 vs 6.9, 8.6 and 10.7 min; time to eyes open, 4.7, 5.7 and 8.0 vs 7.3, 10.5 and 20.8 min; time to squeeze hand, 5.1, 6.5 and 10.2 vs 9.2, 11.1 and 21.1 min; time to tracheal extubation, 5.8, 7.7 and 10.0 vs 9.7, 13.5 and 18.9 min; time to saying their birth date, 7.7, 10.5 and 15.5 vs 13.0, 19.4 and 31.8 min. Patients who received desflurane recalled significantly more of the five words. We did not observe major side-effects and there were no haemodynamic or laboratory changes except for a more marked increase in systolic blood pressure after stopping desflurane. Using a low fresh gas flow (air/oxygen 1 litre min(-1)), pure drug costs were lower for desflurane than for propofol (95 vs 171 Euros day(-1)). CONCLUSIONS: We found shorter and more predictable emergence times and quicker mental recovery after short-term postoperative sedation with desflurane compared with propofol. Desflurane allows precise timing of extubation, shortening the time during which the patient needs very close attention.

[Quantification of blood loss. How precise is visual estimation and what does its accuracy depend on?]. / Quantifizierung von Blutverlusten. Wie genau ist visuelles Schätzen und wovon hängt die Genauigkeit ab?

Estimation of blood loss is a difficult task. Apart from measuring the volume of the suctioned blood the anaesthetist has to make a visual estimate of blood shed on the floor, spread in the surgeons' gowns and gloves and hidden in drapes and sponges at nearly every operation. We were interested in how exact visual estimation of blood loss can be and what factors influence accuracy and precision of the visual estimate. In one OR we simulated typical blood loss scenes occurring during a mock hip joint replacement, using our normal customary equipment of drapes, sponges and containers. More than 8 litres of blood from autologous whole blood donations were partitioned with a graduated measure and syringes and were distributed around the OR in 22 locations in typical ways. 36 members of staff entered the OR one by one and all gave their 22 estimates. Results were analysed by repeated measures analysis of variance. Bias (accuracy) and variation error (precision) were calculated for individuals and groups of individuals. We found a broad deviation of the visual estimates and little coincidence with the actual values. Over- and underestimations by 2 or even 3 were rather common; underestimations were more frequent. We found a significant trend to overestimate diluted blood, even though these certain sites were known to exhibit diluted blood. On the other hand laparotomy pads and sponges fully saturated with blood as well as the simulation of the operative site were grossly underestimated. Age, sex and professional experience (!) did not influence the magnitude of estimation errors, but the professional groups'estimates differed: anaesthetists estimated slightly but significantly more than orthopedic or general surgeons. Obviously our capability to estimate lost blood volumes is more influenced by our belonging to a professional group than by our professional experience. Do we not learn by experience? Diluted blood is overestimated, whereas in some other typical scenes blood loss is grossly underestimated. Simulations such as this one may improve our estimation capabilities and thus result in better patient care in the OR.

[Clinical studies on the peripheral effect of opioids following knee surgery. A literature review]. / Klinische Studien zur peripheren Wirksamkeit von Opioiden nach Kniegelenk-Operationen. Ein Literaturüberblick.

In this article 34 randomized controlled trials examining peripherally mediated opioid effects after knee surgery are discussed. All studies examined small doses of morphine injected intraarticularly at the end of knee surgery, but not all studies did show an analgesic effect of the peripheral opioid. Because of differing study designs a meta-analysis of the data is not possible. Some important factors like those that the respective authors try to explain the contradictory results with are discussed here: The used concentrations, volumes and doses of morphine are not of major importance. An addition of adrenaline to the study drug, as well as the use of a tourniquet and the time interval between the intra-articular injection and tourniquet release do not seem crucial either. The use of intra-articular drainage (which is opened 10 min after injection of the study drug) and of patient-controlled analgesia as an evaluative method also do not seem to play a major role. But it is remarcable that peripheral opioid effects have often been described after general and local anesthesia but only once after regional anaesthesia. It may be that the activation or expression of peripheral opioid receptors is inhibited by the blockade of input to the central nervous system. Animal experiments are needed to clarify this issue. But it may also be that postoperative pain after regional anaesthesia does not reach a level high enough to make an analgesic effect measurable. If patients after regional anesthesia are not considered, 20 studies out of 29 were able to demonstrate opioid effects whereas 9 were not: The work of Heard and coll. as well as Ruwe and coll. must be criticized because of methodological shortcomings. In the remaining 7 studies the patients of the comparative groups only show low pain scores which may make it impossible to measure an analgesic effect by intraarticular morphine. In summary it can be concluded that very small doses of morphine injected intra-articularly after knee surgery do exert an analgesic effect. In some studies this effect lasted even up to 48 h. But at least during the first two hours the effect is small or else doubtfull. Therefore a combination with bupivacain, a local anesthetic which acts rapidly but only for some hours can be recommended. Most authors testing this combination found it most useful.