S. Wilhelm

Bovine haemoglobin is more potent than autologous red blood cells in restoring muscular tissue oxygenation after profound isovolaemic haemodilution in dogs

PurposeThis study compares the effects of stored red cells, freshly donated blood and ultrapurified polymerized bovine haemoglobin (HBOC) on haemodynamic variables, oxygen transport capacity and muscular tissue oxygenation after acute and almost complete isovolaemic haemodilution in a canine model.MethodsFollowing randomization to one of three groups, 24 anaesthetized Foxhounds underwent isovolaemic haemodilution with 6% hetastarch to haematocrit levels of 20%, 15% and 10% before they received isovolaemic stepwise augmentation of 1 g · dl−1 haemoglobin. In Group 1, animals were given autologous stored red cells which they had donated three weeks before. In Group 2, animals received freshly donated blood harvested during haemodilution. In Group 3, animals were infused with HBOC. Skeletal muscle tissue oxygen tension was measured with a polarographic 12 μ needle probe.ResultsIn all groups, heart rate and cardiac index were increased with decreasing vascular resistance during haemodilution (P < 0.05). Haemodynamic variables showed a reversed trend during transfusion when compared to haemodilution but remained below baseline (P < 0.05). Arterial and venous oxygen content were changed in parallel to changes of haematocrit and haemoglobin concentrations but were lower in Group 3 than in Groups 1 and 2 (P < 0.05) during transfusion. In contrast, the oxygen extraction ratio was higher in Group 3 (59 ± 8%, P < 0.01) at the end of transfusion than in Group 1 (37 ± 13%) and 2 (32 ± 5%). In Group 3, mean tissue oxygen tension increased from 16 ± 5 mmHg after haemodilution to 56 ± 11 mmHg after transfusion (P < 0.01) and was higher than in Group 1 (41 ± 9, P < 0.01) and Group 2 (29 ± 11, P < 0.01). While in Group 3 an augmentation of 0.7 g · dl−1 haemoglobin resulted in restoring baseline tissue oxygenation, higher doses of 2.7 g · dl−1 and 2.1 g · dl−1 were needed in Groups 1 and 2 to reach this level (P < 0.01).ConclusionThe results show a higher oxygenation potential of HBOC than with autologous stored red cells because of a more pronounced oxygen extraction.RésuméObjectifCette étude compare les effets des hématies conservées, du sang fraîchement prélevé et de l’hémoglobine bovine polymérisée ultrapurifiée (HBOC) sur les variables hémodynamiques, la capacité de transport en oxygène et l’oxygénation du tissu musculaire après hémodilution isovolémique aiguë et presque complète sur un modèle canin.MéthodesAprès randomisation en trois groupes, 24 fox-hounds ont subi, une hémodilution isovolémique en paliers avec de l’hétastarch à 6% pour réaliser des hématocrites de 20%, 15% et 10% avant de recevoir une augmentation iso-volémique en paliers de 1 g · dl−1 d’hémoglobine. Dans le groupe 1, les chiens ont reçu les hématies autologues conservées prélevées trois semaines auparavant. Dans le groupe 2, les animaux ont reçu de sang frais recueilli au moment de l’hémodilution. Dans le groupe 3, les animaux ont été perfusés avec HBCO. La tension en oxygène du tissus musculaire a été mesurée avec une sonde polarographique.RésultatsDans tous les groupes, la fréquence et l’index cardiaques ont augmenté avec la baisse de la résistance vasculaire pendant l’hémodilution (P < 0,05). Pendant la transfusion, les variables hémodynamiques ont révélé une tendance inverse de celle de l’hémodilution mais sont demeurées sous la ligne de base (P < 0,05). Pendant la transfusion, les contenus artériels et veineux eh oxygène ont changé parallèlement aux changements de l’hématocrite et de la concentration de l’hémoglobine mais étaient plus bas dans le groupe 3 que dans les groupes 1 et 2 (P < 0,05). Par contre, à la fin de la transfusion, l’extraction de l’oxygène a été plus grande dans le groupe 3 (59 ± 8%, P < 0,01) que dans les groupes 1 (37 ±13%) et 2 (31 ± 5%). Dans le groupe 3, après la transfusion, la tension tissulaire moyenne en oxygène a augmenté de 16 ±5 mmHg à 56 ± 11 mmHg (P < 0,01) et était plus élevée que dans les groupes 1(41 ± 9, P < 0,01) et 2 (29 ± 11,P < 0,01). Alors que dans le groupe 3, une augmentation de 0,7 g · dl−1 a permis de ramener l’oxygénation tissulaire à la ligne de base, des quantités plus grandes (2,7 g · dl−1 et de 2,2 g · dl−1) ont été requises pour atteindre ce niveau dans les groupes 1 et 2.ConclusionCes résultats montrent un potentiel d’oxygénation plus élevé avec HBCO qu ’avec des hématies autologues conservées en raison d’une extraction plus prononcée de l’oxygène.

Bovine hemoglobin increases skeletal muscle oxygenation during 95% artificial arterial stenosis

BACKGROUND This study investigates the effect of a stroma-free ultrapurified bovine hemoglobin solution (HBOC) on skeletal muscle tissue oxygenation in comparison with hetastarch during nearly complete arterial stenosis. METHODS Fourteen foxhounds were intravenously anesthetized and mechanically ventilated with 30% oxygen in air. Catheters were inserted into the right femoral artery and vein for measurements of hemodynamic parameters and blood gas sampling. Arterial blood flow of the left popliteal artery was measured by means of an electromagnetic flow probe. Skeletal muscle tissue oxygen tension (tpO2) was measured in the left gastrocnemius muscle by using a stepwise driven polarographic needle probe creating histograms from 200 single tpO2 measurements. After isovolemic hemodilution with Ringers lactate solution to a hematocrit of 25%, a 95% artificial stenosis of the popliteal artery was established. The animals then randomly received two applications of either 50 ml HBOC (molecular weight, 32,000 to 500,000; hemoglobin, 13 +/- 1 gm/dl-1) or 200 ml 6% hetastarch 200,000/0.5. Variables were measured at baseline, after hemodilution, 30 minutes after stenosis, and 15 minutes after two applications of the respective compound. RESULTS Demographic data, muscle temperature, and arterial blood gases did not differ between groups. With the exception of higher mean arterial and mean pulmonary artery pressures in HBOC-treated animals, hemodynamics did not differ between groups. In both groups oxygen delivery and oxygen consumption of the muscle decreased in parallel to the decreasing blood flow during arterial stenosis. In contrast, oxygen extraction ratio increased after infusion of HBOC and was higher after the second application when compared with hetastarch-treated animals (p < 0.05). During stenosis tpO2 was decreased in both groups when compared with baseline (p < 0.001). Mean tpO2 remained at decreased levels after administration of hetastarch but increased to nearly baseline values after HBOC treatment (p < 0.001). CONCLUSIONS The data suggest that increased oxygen extraction in the HBOC group is associated with improved skeletal muscle tissue oxygenation during severe arterial stenosis.

Wound Infiltration and Drain Lavage with Ropivacaine After Major Shoulder Surgery

UNLABELLED Subcutaneous infiltration and wound lavage with ropivacaine is an alternative to opioids after major shoulder surgery. However, the efficacy and potential toxicity of this method remain unclear. We therefore evaluated plasma ropivacaine concentrations after shoulder infiltration and wound lavage. We subsequently quantified the efficacy of two ropivacaine concentrations. Patients undergoing major shoulder surgery were anesthetized with alfentanil and propofol. The initial patients (n = 18) received ropivacaine 7.5 mg/mL and ropivacaine plasma concentrations were measured in 15-min intervals. The subsequent 45 patients were randomly assigned to: 1) isotonic saline, 2) 3.75 mg/mL ropivacaine, or 3) 7.5 mg/mL ropivacaine. Ten milliliters of each solution was administered subcutaneously and 20 mL was injected into the wound drain which was clamped for 10 min. Supplemental postoperative pain relief was provided by patient-controlled anesthesia using the opioid piritramid (3.5-mg boluses, 6-min lock-out). Postoperative pain scores were recorded on a 100-mm visual analog scale for 4 h in the initial patients and for 10 h in the second part of the study. Unbound ropivacaine plasma concentrations peaked after 15 min at 0.08+/-0.09 microg/mL; the maximum was 0.30 microg/mL, compared with a toxic threshold of 0.6 microg/mL. In the second part of the study, pain scores were significantly lower after 3.75 mg/mL (20+/-15 mm) or 7.5 mg/mL (10+/-9 mm) ropivacaine than saline (35+/-10 mm). Piritramid requirements differed significantly in the three groups, being highest with saline and lowest with ropivacaine 7.5 mg/mL. We conclude that wound infiltration and lavage with 30 mL ropivacaine 7.5 mg/mL after major shoulder surgery resulted in very low pain scores and opioid requirement. IMPLICATIONS Wound infiltration and lavage with 30 mL ropivacaine 7.5 mg/mL after major shoulder surgery resulted in very low pain scores and opioid requirement.

Präoperative Hämodilution mit bovinem Hämoglobin Akute hämodynamische Auswirkungen bei Patienten in der Leberchirurgie

ZusammenfassungHämoglobinlösungen sind kolloidale Volumenersatzpräparate, die Sauerstoff transportieren und damit eine Alternative zur homologen Transfusion von Erythrozyten darstellen können. Ziel der vorliegenden klinischen Studie war es, ein polymerisiertes ultragereinigtes Rinderhämoglobin (HBOC-201) im Vergleich zu Hydroxyäthylstärke (HES) auf Veränderungen der Hämodynamik und der O2-Transportparameter während und nach Hämodilution zu untersuchen. Material und Methoden: Nach Zustimmung durch die Ethikkommission wurden 12 Patienten (6 m. u. 6 w., Alter 59±10 J., ASA I–II, die sich einer Leberteilresektion unterziehen mußten, randomisiert auf 2 Gruppen verteilt. In Gruppe 1 erhielten die Patienten im Anschluß an eine präoperative Eigenblutspende von 1 l eine Infusion von 3 ml·kg−1 6% HES 70000/0,5 über 30 min sowie 2 l Ringerlaktat. Patienten der Gruppe 2 erhielten 2 l Ringerlaktat und über 30 min 0,4 g·kg−1 HBOC-201. Blutgasanalysen, Hämodynamik und Parameter des O2-Transports wurden vor und nach Eigenblutspende, während und nach Infusion, bei Operationsbeginn und auf der Intensivstation gemessen. Ergebnisse: Der arterielle Mitteldruck stieg unter Infusion von HBOC-201 im Gegensatz zu HES um maximal 18% gegenüber der Ausgangsmessung an. Während der pulmonale Gefäßwiderstand in der HBOC-201-Gruppe einen Trend zu höheren Werten als in der HES-Gruppe zeigte, stieg der systemische Gefäßwiderstand unter Infusion von HBOC-201 im Vergleich zum Ausgangswert um maximal 42% und war doppelt so hoch wie in der HES-Gruppe. Der Cardiac-Index lag in der HBOC-201-Gruppe unter den Werten der HES-Gruppe. Gemischt-venöse O2-Konzentrationen und -Sättigung sowie das errechnete O2-Angebot waren während und nach HBOC-201 Applikation niedriger als in der HES-Gruppe, während die O2-Extraktion nach Infusion von HBOC-201 höher war als nach HES. Die maximale Plasmakonzentration von HBOC-201 betrug 1,0±0,2 g·dl−1, die intravasale Halbwertszeit im Mittel 8,5 h. Im Urin war kein freies Hämoglobin nachweisbar. Schlußfolgerung. Die Ergebnisse zeigen bei guter Verträglichkeit der HBOC-201-Lösung einen vasokonstriktorischen Nebeneffekt, der zu einer Steigerung insbesondere des systemischen Gefäßwiderstands führt.AbstractHaemoglobin solutions can be an alternative to allogeneic red-cell transfusions because they combine colloid osmotic with oxygen transport properties. Since severe toxic side effects have been overcome by ultrapurification, clinical interest has been focused on haemodynamics changes during application of haemoglobin preparations. The present clinical study examines changes of haemodynamic and oxygen transport parameters during and after haemodilution with ultrapurified polymerized bovine haemoglobin (HBOC-201) in comparison to hydroxyethyl starch (HES). Methods: After approval of the Ethics Committee, 12 patients (6 males and 6 females, mean age 59±10 years, ASA 1-2) undergoing elective liver resection were randomly allocated to receive either 3 ml·kg−1 6% HES 70000/0.5 (group 1) or 0.4 g· kg−1 HBOC-201 (group 2) within 30 min following autologous blood donation of 1 l and substitution with 2 l Ringer’s lactate. Measurements of blood gases, haemodynamics, and oxygen transport parameters were performed after induction of general anaesthesia, prior to and after blood donation, during and after infusion, at the beginning of surgery, and in the intensive care unit. Results: Demographic characteristics did not differ between groups. In contrast to the HES group, mean arterial pressure increased by 18% over baseline measurements in group 2. While pulmonary vascular resistance showed a trend to higher values in group 2, systemic vascular resistance increased to a maximum of 42% over baseline in group 2 and was twice as high as in the HES group. The cardiac index was lower in the HBOC-201 group than in the HES group. During and after HBOC-201 infusion, mixed-venous oxygen saturation and content and calculated oxygen delivery were lower in group 2 in comparison to group 1, while the oxygen extraction ratio was higher in group 2. Free haemoglobin reached a maximal concentration of 1.0±0.2 g·dl−1 30 min after the HBOC-201 infusion was started, but was not detectable in urine over time. The mean intravascular half-life of HBOC-201 was 8.5 h. Conclusions: Patients did not show any severe complications during and after infusion of HBOC-201. However, vasoconstrictive side effects resulted in increased systemic but not pulmonary resistance. Ongoing studies with higher doses of HBOC-201 applied in a larger number of patients will probably reveal potential clinical consequences of the demonstrated haemodynamic changes.

Subarachnoid Sufentanil for early postoperative pain management in orthopedic patients : A placebo-controlled, double-blind study using spinal microcatheters

BackgroundContinuous spinal anesthesia is frequently used for intraoperative anesthesia but rarely for postoperative pain management. Because even small doses of local anesthetics can be associated with motor deficits, subarachnoid opioid injection may be an alternative. MethodsEighty patients randomly received a subarachnoid injection of 10 &mgr;g sufentanil, 5 mg bupivacaine, 2.5 &mgr;g sufentanil plus 2.5 mg bupivacaine, or saline through 28-gauge spinal microcatheters for early postoperative pain relief after major lower-limb surgery (n = 20 in each group). Hemodynamic and respiratory parameters, pain scores, and motor function were monitored, and sufentanil concentrations in plasma and cerebrospinal fluid were measured. Ten additional patients received up to three repetitive injections of 10 &mgr;g sufentanil over 24 h. ResultsAll drugs provided excellent pain relief within 15 min after injection, lasting 128 ± 61 min with sufentanil, 146 ± 74 min with bupivacaine, and 167 ± 78 min with the mixture. Patients receiving bupivacaine showed the highest cephalad extension of sensory block (median, T6) and the most intense motor block, whereas patients given only sufentanil had no motor deficit. The duration of analgesia was shorter after subsequent sufentanil injection (100–115 min) than after the first injection (198 ± 70 min). Six of 50 patients with sufentanil experienced a short episode of respiratory depression within 30 min after the first injection. Cerebrospinal fluid concentrations of sufentanil peaked at 5 min after injection (183 ± 167 ng/ml) but were at the level of detection in the plasma. ConclusionsSufentanil injected through microspinal catheters provided profound pain relief without impairing motor function when compared with bupivacaine. However, close monitoring remains mandatory in this setting.

Comparison of continuous spinal with combined spinal-epidural anesthesia using plain bupivacaine 0.5% in trauma patients

We investigated the efficacy and complications of microcatheter spinal anesthesia (CSA) in comparison to a combined spinal-epidural technique (CSE) using plain bupivacaine 0.5%. Sixty trauma patients randomly received either CSA using a 22-gauge Sprotte needle and a 28-gauge microcatheter or CSE after insertion of a 22-gauge epidural catheter through an 18-gauge Tuohy needle followed by dural puncture with a 25-gauge pencil-point needle inserted through the backeye of the Tuohy needle. An initial subarachnoid bolus of 2 mL of plain bupivacaine 0.5% was injected. If analgesia did not reach T12 within 20 min, supplemental bupivacaine was injected either intrathecally or epidurally up to a maximum of 5 mL in the CSA group or 16 mL in the CSE group. Mean arterial blood pressure, heart rate, and analgesic levels were recorded. On postoperative Day 4, patients were interviewed for postanesthetic complaints. Technical problems were more frequent in the CSE group than in the CSA group (47% vs 13%). Performance of anesthesia was faster (8 +/- 3 vs 15 +/- 8 min) and the total dose of bupivacaine lower (3.2 +/- 1.0 vs 9.7 +/- 5 mL) in patients who received CSA. The incidence of hypotension did not differ significantly. However, more patients in the CSE group were treated for bradycardia (4 vs 0). The number of patients suffering from postdural puncture headache was comparable in both groups, but there were more patients with lower back pain in the CSE group (8 vs 2). In conclusion, our data suggest that microcatheter CSA is not associated with an increased rate of complication in patients with lower limb fractures. (Anesth Analg 1997;85:69-74)

Propofol reduces emesis after sufentanil supplemented anaesthesia in paediatric squint surgery

Background. Squint surgery is associated with a high incidence of postoperative emesis. The purpose of this prospective study was to examine the influence of propofol and isoflurane anaesthesia on the incidence of postoperative nausea and vomiting in children.

Acute normovolaemic haemodilution beyond a haematocrit of 25%: ratio of skeletal muscle tissue oxygen tension and cardiac index is not maintained in the healthy dog

BACKGROUND AND OBJECTIVE The study investigated the effect of acute normovolaemic haemodilution on haemodynamics, blood flow and oxygen transport variables with regard to skeletal muscle tissue oxygenation in a canine model. METHODS Twenty foxhounds were anaesthetized, mechanically ventilated with 30% oxygen in air and underwent first-step normovolaemic haemodilution with Ringers lactate solution to haematocrit (Hct) 30 and 25% and second-step acute normovolaemic haemodilution with 6% Hetastarch 70,000/0.5 to Hcts of 20, 15 and 10%. Catheters were inserted into femoral arteries and veins and into the pulmonary artery for measurements ofhaemodynamics, temperature, and sampling of arterial and mixed-venous blood. A flow probe was placed around the left femoral artery. Skeletal muscle tissue oxygen tension (tPO2) was measured in the gastrocnemius muscle using a stepwise driven polarographic needle probe creating histograms from 200 single tPO2 measurements. RESULTS Until a Hct of 25% was reached, the heart rate, mean arterial pressure, global and muscular oxygen delivery and consumption remained constant, while the cardiac index and oxygen extraction ratio were significantly increased when compared with baseline. The median tPO2 was significantly decreased at Hcts 15 and 10%, despite increased cardiac index and regional blood flow. The ratio of tPO2 and cardiac index as a marker for efficiency of acute normovolaemic haemodilution started to decline beyond Hcts of 25% (change of slope). CONCLUSIONS In acute normovolaemic haemodilution to the level of Hct of 25%, the ratio between tPO2 and cardiac index decreases in the healthy dog, indicating an uneconomic relation at the threshold of Hct of 25%.

Bovines Hämoglobin HBOC-201 verhindert eine Reduktion des Sauerstoffpartialdrucks im poststenotischen Skelettmuskel

ZusammenfassungDie Studie untersucht die Wirkung der ultra-gereinigten polymerisierten bovinen Hämoglobinlösung HBOC-201 auf den Sauerstoffpartialdruck des Skelettmuskels bei intravenöser Applikation vor Anlage einer 95%igen arteriellen Stenose. Methoden: Zwölf Foxhounds wurden intravenös anästhesiert und kontrolliert mit 30 Vol.-% Sauerstoff in Luft beatmet. In die rechte Femoralarterie und -vene wurden Katheter zur Messung hämodynamischer Parameter und zur Entnahme von Blutgasanalysen plaziert. Der Blutfluß der linken A. poplitea wurde mittels eines elektromagnetischen Flußmessers bestimmt. Der Gewebssauerstoffpartialdruck (tpO2) wurde im linken M. gastrocnemius mit einer polarographischen Meßsonde gemessen. Nach Hämodilution der Tiere mit Ringerlösung bis zu einem Hämatokrit von 20% wurden die Tiere randomisiert in zwei Gruppen zu je 6 eingeteilt. In Gruppe 1 wurde den Tieren 200 ml Hämodilutionsblut retransfundiert, während in der Gruppe 2200 ml HBOC-201 (MG 32000–500000, Hb 13±1 g·dl−1) infundiert wurden. Nach einer 15minütigen Ruhephase wurde eine 95%ige arterielle Stenose der linken A. poplitea angelegt. Den Tieren der Gruppe 1 wurde jeweils 45 und 75 min nach Anlage der Stenose je 200 ml 6% Hydroxyäthylstärke (HÄS, 200000; 0,5) infundiert, während den Tieren der Gruppe 2 je 200 ml Ringerlösung infundiert wurde. Messungen erfolgten nach Instrumentierung der Tiere, nach Hämodilution und Applikation von Blut oder HBOC-201 sowie jeweils 30, 60 und 90 min nach Anlage der Stenose. Ergebnisse: Muskeltemperatur, arterielle Blutgase und hämodynamische Parameter zeigten keine Gruppenunterschiede. Lediglich der mittlere Pulmonalarteriendruck lag nach HBOC-201 Infusion höher als in der Vergleichsgruppe. Der Sauerstofftransport zum Muskel und der Sauerstoffverbrauch sank in beiden Gruppen entsprechend der Reduktion des poststenotischen Blutflusses ab. Die Sauerstoffextraktionsrate des Muskels lag in Gruppe 2 nach HBOC-201 Infusion im Vergleich zur Gruppe 1 höher (p<0,05). Der tpO2 sank im Skelettmuskel nach Anlage der Stenose in Gruppe 1 ab (p<0,001) und zeigte keine Änderung nach Infusion von HÄS. In Gruppe 2 blieb der tpO2 auch nach Anlage der Stenose über den gesamten Untersuchungszeitraum unverändert. Schlußfolgerung: Die Ergebnisse dieser Untersuchung zeigen, daß die Applikation von HBOC-201 vor Anlage einer arteriellen Stenose einen Abfall des O2-Partialdrucks im poststenotischen Muskelgewebe verhindern kann.AbstractWe investigated the effects of ultrapurified polymerized bovine hemoglobin (HBOC-201) on skeletal muscle tissue oxygen tension when applied before establishment of a nearly complete arterial stenosis. Methods: Twelve foxhounds were anaes-thetized IV and mechanically ventilated with 30% oxygen in air. Catheters were inserted into the right femoral artery and vein for measurements of haemodynamic parameters and blood-gas sampling. Arterial blood flow of the left popliteal artery was measured by an electromagnetic flow probe. Skeletal muscle tissue oxygen tension (tpo2) was measured in the left gastrocnemic muscle using a stepwise-driven polarographic needle probe, creating histograms from 200 single tpO2 measurements. Following isovolaemic haemodilution with Ringer’s solution to a target haematocrit of 20%, the animals were randomly assigned to receive either 200 ml of predonated fresh blood (group 1) or 200 ml of HBOC-201 (MW 32000–500000; Hb 13±1 g·dl−1; group 2). After a 15-min stabili-zation period, a 95% artificial stenosis of the left popliteal artery was established. While animals of group 1 received two applications of 200 ml 6% hetastarch (HES, 200000; 0.5), animals of group 2 received 200 ml Ringer’s solution 45 and 75 min after establishment of the arterial stenosis, respectively. Variables were measured at baseline, after haemodilution and application of the respective compound, and 30, 60 and 90 min after establishment of the stenosis. Results: Demographic data, muscle temperature and arterial blood gases did not differ between groups. With the exception of a higher mean pulmonary artery pressure in HBOC-201-treated animals, haemodynamics did not differ between groups. In both groups oxygen delivery and oxygen consumption of the muscle decreased in parallel to the de- creasing blood flow during arterial stenosis. In contrast, oxygen extraction ratio increased after infusion of HBOC-201 and remained unchanged during stenosis (P<0.05). In group 1, the tpO2 decreased during stenosis when compared to baseline (P<0.001) and remained decreased after administration of HES. In contrast, administration of 200 ml of HBOC-201 before establishment of the arterial stenosis sustained the tpO2 values at nearly baseline levels during stenosis. Skeletal muscle tissue oxygen tension was higher after HBOC-201 infusion during stenosis when compared to HES infusion (P<0.001). Conclusion: These data suggest that haemoglobin solutions can reach poststenotic tis-sues. The increased oxygen extraction after application of HBOC-201 is associated with improved skeletal muscle oxygen tension during severe arterial stenosis.

Long-term follow-up study in liver resection patients receiving a haemoglobin-based oxygen carrier

Since improvement in purification of stroma-free haemoglobin solutions enables the production of cell-free oxygen carriers which are free of toxic side-effects on liver and kidneys, clinical interest in such material has been aroused during the last years. Animal models have shown that ultrapurified polymerized bovine haemoglobin (HBOC-201) is free of severe hepato-renal side-effects and provides excellent tissue oxygenation [1,2,3]. The present prospective study was designed to examine safety and tolerance of HBOC-201 applied during haemodilution in patients prior to liver resection.