POS0194 MORBIDITY AND MORTALITY OF BREAKTHROUGH COVID-19 IN PATIENTS WITH IMMUNE MEDIATED CONDITIONS ON B CELL DEPLETING THERAPIES AND THE EFFECTS OF MONOCLONAL ANTIBODY TREATMENT

Background

Among immunocompromised patients with immune mediated inflammatory diseases (IMIDs), those undergoing therapy with B cell depleting agents are among the most vulnerable to both severe COVID-19 disease and sub-optimal response to COVID-19 vaccines(1). Numerous studies have documented suppressed humoral, but relatively maintained cell mediated, responses to COVID-19 vaccines in these patients. However, the clinical significance of such immunity in terms of protection from infection and its sequelae are poorly understood. We have analyzed a large cohort of vaccinated IMIDs patients undergoing B cell depleting therapy for the presence of breakthrough infection and assessed their outcomes.

Objectives:

To define the frequency and outcomes of COVID-19 breakthrough infection in fully or partially vaccinated IMIDs patients receiving B cell depleting therapies.

To assess the characteristics and risk factors for severe outcomes and death.

Methods

All pharmacy records from within a large health care system were electronically searched for patients undergoing B cell depleting therapies with approved monoclonal antibodies in 2020. Records with ICD codes for IMIDs but not malignancies were included; patients must also have had at least one documented COVID-19 vaccine. From this cohort all patients with breakthrough COVID-19 disease from time of 1st vaccination through December 15, 2021 were identified; each record was hand-reviewed to extract clinical data including vaccine history, demographics, comorbidities, use of monoclonal antibodies, dose and timing of B cell depleting therapy, and outcomes as assessed by an 8 point NIH ordinal scale. Univariate and multivariable logistic/proportional-odds regression models were used to examine the risk factors for severe outcomes.

Results

A total of 1677 IMIDs patients were identified who received any B cell depleting monoclonal antibody and at least one COVID-19 vaccine in 2021. From this cohort 74 patients (4.4%) experienced a breakthrough COVID-19 infection. Among the breakthrough patients 34 (46%) had a rheumatic disease (RA 11, AAV 15, SLE 2), 34 (46%) had CNS inflammatory disease (MS 32, 2 other), and 6 (8%) had immune hematologic/miscellaneous diseases. Four patients had a previous history of COVID-19 infection. Overall 24 (35%) were hospitalized with 11 patients requiring critical level care (15%) and 6 deaths (8 %). All fatal cases had rheumatic diseases. Monoclonal antibodies were given as outpatient therapy to 21 patients and among these only 1 patient was hospitalized without requiring O2 and none died. In univariate analysis only number of comorbidities had a significant positive effect (p=.001) on severe outcomes (i.e. groups 1-4 vs. groups 5-8: Table 1) while monoclonal antibody therapy was associated with more favorable outcomes (p=.005 group 1-2 vs.3-8, Table 1). There were no associations between the dose, duration or timing of the B cell therapy, concomitant therapies including glucocorticoids, vaccine status (incomplete, complete, boosted) or date of vaccination with severe outcomes.

Conclusion

In IMIDs patients treated with B cell depleting therapies breakthrough infections are common with many experiencing severe outcomes. Concomitant comorbidities were associated with risk of severe disease. Monoclonal antibody therapy was used in only 28% but was associated with enhanced clinical outcomes with only 1 in 21 requiring hospitalization and zero mortality. This population of immunocompromised patients remains vulnerable to COVID-19 disease despite vaccination. More aggressive use of outpatient management with monoclonal antibody therapy and other preventive and therapeutic measures are urgently needed.

Reference

[1]Samuel Bitoun et al Rituximab impairs B-cell response but not T-cell response to COVID-19 vaccine in auto-immune diseases First published: 28 December 2021 Arthritis and Rheumatology https://doi.org/10.1002/art.42058

Disclosure of Interests

cassandra calabrese Speakers bureau: Sanofi-regeneron, Consultant of: Sanofi-regeneron, Elizabeth Kirchner Consultant of: Janssen, M Elaine Husni Consultant of: Abbvie, BMS, Novartis, Lilly, Pfizer, UCB, Regeneron, Janssen, Brandon Moss Consultant of: Biogen advisory board, Grant/research support from: Genentech/Roche and Novartis as part of investigator-initiated studies, Anthony Fernandez Consultant of: Consulting: AbbVie, Novartis, Mallinckrodt, UCB, BMS, Boehringer Ingelheim, Alexion, Grant/research support from: Research: AbbVie, Novartis, Pfizer, Corbus, Mallinckrodt, Yuxuan Jin: None declared, Leonard Calabrese Speakers bureau: Sanofi, Janssen, AbbVie, ChemoCentryx, GSK, AstraZeneca, Consultant of: Sanofi, Jansen, AbbVie, ChemoCentryx, GSK, AstraZeneca, BMS, Genentech

Rheumatic immune-related adverse events of checkpoint therapy for cancer: case series of a new nosological entity

Immunotherapy of cancer with checkpoint inhibitors has been associated with a spectrum of autoimmune and systemic inflammatory reactions known as immune-related adverse events (irAEs). Rheumatic irAEs are infrequently reported and extensively described. Here, we report our experience over an 18-month period with 15 patients evaluated in the rheumatology department for rheumatic irAEs. We identified 13 patients without pre-existing autoimmune disease (AID) who subsequently developed rheumatic irAEs, and two with established AID referred pre-emptively. irAEs encountered included: inflammatory arthritis, sicca syndrome, polymyalgia rheumatica-like symptoms and myositis. All cases required glucocorticoids, and three required a biological agent. Rheumatic irAEs led to temporary or permanent cessation of immunotherapy in all but five patients. One patient with pre-existing AID experienced a flare after starting immunotherapy. Our findings underscore that rheumatic irAEs are complex, at times require additional immunosuppressive therapy, and may influence ongoing immunotherapy regimens for the primary disease. Similar irAEs will be increasingly seen as checkpoint inhibitors adopted as standard of care in the community.

Global color estimation of special-effect coatings from measurements by commercially available portable multiangle spectrophotometers

Colors of special-effect coatings have strong dependence on illumination/viewing geometry and an appealing appearance. An open question is to ask about the minimum number of measurement geometries required to completely characterize their observed color shift. A recently published principal components analysis (PCA)-based procedure to estimate the color of special-effect coatings at any geometry from measurements at a reduced set of geometries was tested in this work by using the measurement geometries of commercial portable multiangle spectrophotometers X-Rite MA98, Datacolor FX10, and BYK-mac as reduced sets. The performance of the proposed PCA procedure for the color-shift estimation for these commercial geometries has been examined for 15 special-effect coatings. Our results suggest that for rendering the color appearance of 3D objects covered with special-effect coatings, the color accuracy obtained with this procedure may be sufficient. This is the case especially if geometries of X-Rite MA98 or Datacolor FX10 are used.

In a study for acne vulgaris, sequence-based HLA typing showed a novel DPB1 allele, DPB1*2402

In this paper, we characterize the novel human leucocyte antigen (HLA)-DPB1*2402 allele that we found in a patient suffering from acne vulgaris. In comparison to the closest related allele DPB1*0401, HLA-DPB1*2402 has a single nucleotide exchange at position 115 (202), T replaces G. In consequence, codon 39 (68) TAC encodes for tyrosine in the novel allele instead of aspartic acid 39 (68) GAC in DPB1*0401.

Rapid exchange of large numbers of donor- and host leukocytes after human liver transplantation

After liver transplantation, the release of donor leukocytes into the host and the uptake of host leukocytes by the graft is one of the earliest immunologic interactions between donor and host. Using three-color flow cytometry, these interactions were investigated in eight patients from 5 min-24 h after receiving HLA unmatched liver grafts. Five minutes after reperfusion, 5.0 % +/- 1.4 % of all blood leukocytes in the host were of donor origin, decreasing to 1.1 % +/- 0.8 % after 24 h. Donor granulocytes preferentially disappeared from the host circulation, whereas no differences were found between NK-cells and various B- and T cell subpopulations. Furthermore, host granulocytes were preferentially retained in the donor liver. Thus, despite extensive pre-operative perfusion, more than 10(9) donor leukocytes quickly leave the liver graft while host granulocytes preferentially accumulate there. A better understanding of the molecular mechanisms mediating these early interactions might help to develop new strategies for diagnosis and therapy of liver graft rejection.

Postoperative altered plasma growth hormone levels--a predictor for postoperative complications? A case report

We compared the onset of predictors for postoperative complications (lactate, total T2 (tT2), total T4 (tT4) and cortisone) retrospectively with the onset of altered growth hormone (GH) concentration in a patient who had had a lethal postoperative outcome and in 13 patients who were without postoperative complications for a period of 24 hours postoperatively. Compared with the values of the patients without postoperative complications, GH values were elevated (68-fold) 1 h after surgery to 103 ng/ml and lactate was increased (12-fold) to 12.7 mmol/l at 6 h postoperatively in the patient with the lethal outcome. The other parameters measured (tT3, tT4 and cortisone) showed no rapid alteration during the first hours postoperatively. This case report suggests that the rapid postoperative onset of raised GH concentration in plasma may be an earlier marker for postoperative complications than the 'established' predictors.

Postoperative pattern of various hormonal and metabolic variables. A pilot study in patients without complications following cardiac surgery

The use of single predictors for threatening postoperative complications are widely accepted. However, a typical pattern of multiple parameters could be more helpful than a single predictor. To study this hypothesis, various variables of normal postoperative changes in patients without postoperative complications were investigated. Secondly, this pattern needs to be compared in the future with those findings in patients with postoperative complications. Blood parameters of 13 patients undergoing cardiovascular surgery without postoperative complications for 24 hours were evaluated. Samples were obtained on the afternoon before the operation and 1, 3, 6, 12 and 24 hours after the end of surgery. At one hour postoperation increased levels of the following parameters were noted: growth hormone (p < 0.0001), glucose (p < 0.0001), insulin (p < 0.001), c-peptide (p < 0.001), lactate (p < 0.002), glutamate (p < 0.0001), aspartate (p < 0.001) and total amino acids (p < 0.05), although the concentration of some amino acids decreased. Three hours postoperatively free fatty acids (p < 0.05) were increased. Total-T3 concentrations were reduced postoperatively. Other parameters were not altered. Most of the parameters returned to normal values during the period of observation.

[Anesthesiologic characteristics of isolated hyperthermic liver perfusion with mitomycin C]

The isolated hyperthermic liver perfusion with mitomycin C presents a new technique of regional therapy for irresectable liver tumours. The advantage is a high local concentration of the antitumour agent with reduced systemic side-effects. Isolated hyperthermic liver perfusion is an extensive surgical procedure requiring a veno-venous bypass and a heart-lung machine. Disturbances affecting the base-acid hemostasis, the coagulation system and the cardiocirculatory function can occur. To date, there has been little experience with this technique. The intraoperative changes during the isolated hyperthermic liver perfusion in our series were similar to those seen during orthotopic liver transplantation. In contrast to orthotopic liver transplantation, heparin is given during the anhepatic phase. The reperfusion after isolated hyperthermic liver perfusion was not complicated by severe cardiocirculatory changes. A decrease in body temperature was not observed probably due to the absence of cold, potassium-rich perfusate flowing into the systemic circulation. Two patients developed signs of a reperfusion syndrome within the first hour after reperfusion (decrease in peripheral systemic resistance).

[Endocrine reactions, circulatory and resuscitation behavior in ketamine-midazolam anesthesia. A comparative study of ketamine racemate vs. (S)-ketamine in knee surgery]

Clinically used ketamine is a racemic mixture of two isomers, (S)- and (R)-ketamine, in equal amounts. Previous investigations showed the anaesthetic potency of (S)-ketamine to be three times higher than that of (R)-ketamine. The aim of this study was to compare the effects of (S)-ketamine/midazolam and racemic ketamine/midazolam on endocrine and cardiovascular parameters, recovery, and side effects in unpremedicated patients during knee surgery.

METHODS

41 patients scheduled for elective knee surgery were investigated in a prospective, double-blind, and randomised design. For induction of intravenous anesthesia, patients received 0.1 mg/kg midazolam, 0.003 mg/kg atropine, 1 mg/kg (S)-ketamine or 2 mg/kg racemic ketamine, respectively. For tracheal intubation, 1 mg vecuronium and 1.5 mg/kg suxamethonium were injected. After intubation and relaxation with a total dose of 0.1 mg/kg vecuronium, a continuous infusion of 0.5 mg/kg/h (S)- or 1 mg/kg/h racemic ketamine was administered throughout the surgery. In addition, 0.05 mg/kg/h midazolam was infused continuously in both groups throughout surgery. Ventilation was performed with N2O/O2 (FiO2 0.3). Blood samples were taken using a central venous line five times before induction as well as during and after surgery for analysis of adrenaline, noradrenaline (by high-pressure liquid chromatography with electrochemical detection), anti-diuretic hormone (ADH), adrenocorticotropic hormone (ACTH), and cortisol (by radioimmunoassay). In addition, systolic and diastolic arterial pressure (SAP, DAP), heart rate (HR), and arterial oxygen saturation were measured. The time intervals between the end of ketamine and midazolam infusion and the return of consciousness and orientation were recorded. The incidence and quality of dreams and other side effects were reported by the patients.

RESULTS

Biometric data of the groups were comparable. Plasma adrenaline and noradrenaline did not change significantly during anaesthesia. ADH increased significantly (p < 0.05) after skin incision in both groups.

In vitro evaluation of a glass-ceramic restorative material

The aim of the present study was to evaluate the clinically relevant properties of the recently introduced ceramic material IPS Empress, which is marketed for all-ceramic restorations. The following parameters were investigated: three- and four-point bending strength, bi-axial flexure strength, compressive and diametral tensile strength, compressive strength and marginal fit of full crowns. The results show that this material is a highly developed glass-ceramic with physical properties making this dental material well suitable for adhesively luted restorations.

[Effect of lidocaine administration mode on decreasing injection pain caused by propofol]

Pain is a well known complication of propofol injection. Many methods are described to reduce it but often empirical ways are used. In this study we attempt to determine the effects of premixing propofol with lidocaine or to preinjecting lidocaine in a hand vein in combination with using a tourniquet before we applicated propofol. Our study shows that both ways are able to reduce the injection pain but premixing with lidocaine 0.05% is less effective than giving a bolus of lidocaine before the propofol injection.

[Ventilation via a transnasally placed pharyngeal tube. Comparison with mask ventilation]

OBJECTIVE

The present prospective study was designed to investigate the respiratory function during ventilation via a tube inserted through the nose into the pharynx. Results were compared with respiratory parameters measured during conventional mask ventilation in the same patients.

METHODS

20 ASA physical status I-II patients were studied after approval by the local Ethics Committee. Anaesthesia was induced with alfentanil 15 micrograms/kg and propofol 2.5-3.0 mg/kg and maintained with propofol, 12-15 mg/kg/h. Patients were ventilated via a facemask with oxygen and a tidal volume of approximately 8ml/kg (measurement A). After insertion of a tube (I.D. 7.0-7.5 mm) through the nostril into the pharynx ventilation was repeated in the same manner (measurement B). To secure airway seal a second person closed the patient's mouth and exerted cricoid pressure. Following neuromuscular blockade with suxamethonium (1.5 mg/kg) respiratory parameters were measured again (C). Measurements included pulse oximetry and side stream spirometry with continuous collection of the following data: airway pressure, inspired and expired tidal volume, dynamic compliance, expired volume in one second, inspiratory and expiratory oxygen and carbon dioxide concentration. Pressure-volume and flow-volume loops were displayed continuously.

RESULTS

Ventilation via facial mask or via pharyngeal tube with and without relaxation showed normal endtidal FECO2. The mean values were 4.5 +/- 0.7%, 4.8 +/- 0.4% and 4.6 +/- 0.7%, respectively. Mean oxygen saturation exceeded 98% in each period. Leakage during mask ventilation was 59.3 +/- 65.5 mL and decreased to 40.5 +/- 62.1 mL with the pharyngeal tube, whereas relaxation resulted in a significant increase to 92.3 75.0 mL. Compliance (Cdyn) and expired volume in one second (V 1.0) did not change significantly during the entire period of measurement.

CONCLUSION

The use of a pharyngeally placed tube proved adequate compared to conventional mask ventilation in 20 patients without underlying airway disease.

Cardiopulmonary effects of lying position in anesthetized and mechanically ventilated dogs

Cardiopulmonary effects of right-lateral and supine (on back) lying position were investigated in 8 anesthetized and mechanically ventilated dogs. Complete hemodynamic and respiratory monitoring were obtained. Heart rate was significantly higher, blood pressure, systemic vascular resistance and left and right ventricular stroke work were significantly lower in supine in comparison to right-lateral position. Arterial and mixed-venous oxygen tensions and mixed-venous oxygen saturation were significantly higher in right-lateral position. Compliance was significantly higher and peak ventilation pressure significantly lower in supine position. Arterio-to-mixed-venous-oxygen content difference, oxygen consumption and utilization were significantly higher and respiratory quotient was significantly lower in supine position in comparison to right-lateral position. All other obtained parameters were not be influenced by posture.

[Intraoperative EEG monitoring in hemihepatectomies]

End-stage liver diseases are correlated with specific EEG changes. In chronic liver diseases normal EEG excludes hepatic encephalopathy. To date, it is not known at what time EEG changes appear in liver dysfunction and whether they are to be seen during the unhepatic phase in hemihepatectomies. To clarify this, we analyzed EEGs in 10 patients during hemihepatectomies with the CATEEM system. During the hemihepatectomies an occlusion of the liver hilus for 20-38 minutes (on average 28 minutes) was necessary. During and after the occlusion we found no changes in EEG. We conclude that brief failure of liver function under general anaesthesia is tolerated without danger to the central nervous system.

[Neuromuscular blockade after atracurium and alcuronium with propofol and thiopental]

Does propofol or thiopentone enhance the effect of nondepolarizing muscle relaxants? We evaluated the effects of propofol and thiopentone on the pharmacodynamics of atracurium and alcuronium in 43 surgical patients (ASA I and II) under general anaesthesia.

METHODS

The patients were randomized into five groups, A-E. Anaesthesia was induced in all patients with fentanyl 4 micrograms/kg i.v. Patients in groups A and C patients received thiopentone 7 mg/kg i.v., and relaxation was achieved with alcuronium 0.25 mg/kg (group A) and atracurium 0.5 mg/kg (group C). Electromyography (train of four, TOF) was used to determine the time of onset of relaxation (AZ) and the maximum degree of blockade (T%). The recovery times to 25%, 50% and 75% of baseline muscle strength were recorded. Additionally, the TOF ratio T4:T1 was calculated, indicating the probable end of relaxation at a ratio of 0.7. At the beginning of the recovery phase (T1 = 15%) propofol 1% 3 mg/kg was given, and the effect on the TOF was measured. Patients in groups B and D patients received total intravenous anaesthesia (TIVA) with propofol 1% 6-12 mg/kg per hour continuously after induction with 3 mg/kg. The action profile of alcuronium 0.25 mg/kg (group B) and atracurium 0.5 mg/kg (group D) were recorded. Group E patients received thiopentone (10 mg/kg per hour) under the use of atracurium 0.5 mg/kg. Ventilation was performed with 30%/70% oxygen and N2O. The results were analyzed for significance using the Mann-Whitney U-test (P = 0.019).

RESULTS

A slight difference in AZ was noted for alcuronium under the use of TIVA between propofol and thiopentone: 13 min and 5 min, respectively. Otherwise, the pharmacodynamics (T% and recovery of neuromuscular function) of the two relaxants exhibited no major differences related to thiopentone, propofol or their combination. The TOF was not influenced under additional propofol application. Noteworthy were the wide distribution of the time course of action (up to 3 h) and the magnitude of T% depression under alcuronium.

CONCLUSION

Propofol and thiopentone have no potentiating influence on the time course of action and the magnitude of relaxation with alcuronium and atracurium. Pharmacodynamics of nondepolarizing muscle relaxants do not seem to be influenced by these two hypnotics.

[Fournier's gangrene. Experiences and changes in the disease picture since its initial description]

Fournier's disease mostly occurs in immunosuppressed men in the 5th to 7th decade of life. Bacteria from the urogenital or colorectal tract lead to a rapid spreading soft tissue infection. Painful scrotal or perineal swelling and a black spot as a sign of beginning necrosis are guiding symptoms. Involved bacteria are grampositive cocci, enterobacteriaceae and anaerobes. Main principles of therapy are immediate radical debridement and broad spectrum antibiotics. Sepsis renders the prognosis more infaust.

[Is preventive perioperative dopamine administration of value?]

Dopamine interacts in a dose dependent manner with three types of receptors: the alpha- and beta-adrenoceptors and specific dopaminergic receptors. Hence dopamine can exert direct and indirect renal effects. Stimulation of myocardial beta 1-receptors causes an increase in cardiac output and a subsequent augmentation of renal blood flow. However, a major role of selective renal vasodilation in response to dopamine has been brought into question by recent studies. In addition, dopamine has been shown to decrease tubular transport of sodium and to produce sodium diuresis. This natriuresis may induce volume depletion with further deterioration of renal function. Expectations that low-dose dopamine could have a renal-sparing potential did not prove true. Prophylactic infusion of low-dose dopamine in patients undergoing aortic surgery, orthotopic liver grafting or renal transplantation failed to show a renal protective effect or an improved clinical outcome. The routine use of "renal-dose" dopamine therefore cannot be recommended. More attention must be paid to prevent or abolish prerenal causes of renal impairment. Basic measures as volume expansion, care of cardiocirculatory status and close monitoring of renal function are of special importance.

Blood volume determination with sodium fluorescein and radioactive chromium--a clinical comparison of methods

OBJECTIVE

There exists no method so far for the determination of circulating blood volume as an important parameter of circulatory function widely usable under clinical conditions. Therefore, the present study was designed to investigate whether identical distribution spaces could be measured by two methods for blood volume determination using sodium fluorescein (SoF) and radioactively labelled red blood cells (51Cr*).

DESIGN

Comparative study.

SETTING

Operating theatre, recovery room, or intensive care unit of a university hospital.

PATIENTS

35 patients undergoing abdominal, urological or vascular surgery.

INTERVENTIONS

Simultaneous determinations of blood volume using SoF and 51Cr* in the intra- and postoperative period.

RESULTS

There were no significant differences between the calculated means of blood volume (4,445 vs. 4,407 ml), red cell volume (1,554 vs. 1,540 ml), and plasma volume (2,891 vs. 2,807 ml) for 51Cr*-vs. SoF-stained red blood cells. The coefficient of correlation between the two methods was r = 0.95. The mean percentage error was -0.6% between the two methods, the precision 5.6%.

CONCLUSIONS

SoF-stained erythrocytes allow a determination of the same distribution space as the well-established radioactive method using 51Cr*. Therefore, SoF-staining may replace 51Cr* labelling of red blood cells for the determination of blood volume in patients.

[Combined lung and liver transplantation. Anesthesiologic management]

A 53-year-old man with alpha-1-antitrypsin deficiency had an 8-year history of progressive dyspnoea and two episodes of bleeding oesophageal varices with liver decompensation. After the diagnosis of terminal pulmonary emphysema (Fig. 1) and liver cirrhosis with progressive liver failure was made, he was accepted for combined lung and liver transplantation. METHODS. Anaesthesia was induced with thiopentone and fentanyl and maintained with fentanyl, midazolam, and isoflurane. After relaxation with succinylcholine, the patient's trachea was intubated with a left endobronchial double-lumen tube. Haemodynamic monitoring included arterial, central-venous, pulmonary-artery, and capillary-wedge pressures and cardiac output measurement. Ventilatory monitoring consisted of pulse oximetry, side-stream spirometry, and continuous measurement of arterial and mixed-venous blood oxygen saturation with fibreoptic catheters. A left single-lung transplantation was performed under one-lung ventilation without cardiopulmonary bypass. Prostacyclin was infused to reduce pulmonary vascular resistance. The transplant was ventilated separately with 50% oxygen and positive end-expiratory pressure of 8-10 cm H2O, and then liver transplantation was carried out. The institution of veno-venous bypass during the anhepatic phase failed because of portal-vein and axillary-vein thrombi. RESULTS. Total operation time was 6 h 30 min. Clamping of the left pulmonary artery lasted 45 min and the duration of the anhepatic phase was 92 min. Ventilation and oxygenation during lung transplantation caused no problems (Table 1). Clamping of the left pulmonary artery caused a slight increase in pulmonary vascular resistance (104 to 124 dyn.s.cm-5) and mean pulmonary artery pressure (25 to 27 mm Hg) without a decrease in cardiac index (Table 2). During the anhepatic phase with exclusion of the portal vein and inferior vena cava, a marked decrease in cardiac index (-27.2%) was seen (Table 4). The operation required substitution with 10 units packed red blood cells, 12 units fresh frozen plasma, and 5 platelet concentrates. The post-operative course showed normal liver graft function (Table 5). Acute pulmonary rejection on the 7th day was treated successfully with methylprednisolone. The patient's trachea has extubated 10 days after transplantation and he was discharged from the intensive care unit 2 weeks later. CONCLUSION. The management of this combined lung and liver transplantation was performed according to the experience with isolated lung and liver transplants in our hospital. Aggressive haemodynamic and ventilatory monitoring, including systemic and pulmonary arterial fibreoptic catheters, seems of particular importance in such high-risk procedures.

Calcium carbonate (CaCO3): an efficient and safe phosphate binder in haemodialysis patients? A 3-year study

In an uncontrolled study, 22 dialysis patients (46 +/- 14 years, duration of dialysis 20 +/- 11 months) were treated with CaCO3 over a period of up to 3 years to lower their serum phosphate. The use of 4.5-9 g CaCO3 daily over a period of 9 months led to a reduction of mean serum phosphate from 2.51 to 1.51 mmol/l in 77% of patients, with a simultaneous increase in mean calcium concentration from 2.23 to 2.47 mmol/l, and an improved control of secondary hyperparathyroidism by reduction in mPTH from 1552 to 1032 pg/ml and in APH activity from 6.25 to 4.55 mumol/s/l. In long-term CaCO3 treatment of up to 3 years, however, a constant effective phosphate reduction could not be achieved. There was a progression (77%) of pre-existing microcalcification and a new appearance (42%) of microcalcification in vessels and soft-tissue areas of the hand. The percentage of patients with soft-tissue calcification increased from 43 to 67% during a treatment period of 3 years. We conclude that CaCO3 alone is not suitable on a long-term basis for phosphate reduction in dialysis patients.

[2-Amino-oxazoles as potential H-bonding agents in virostatic research. 4. Pharmacokinetics and pharmacologic-toxicologic profile of 2-guanidino-4,5-dipropyloxazole hydrochloride]

Out of the group of 2-amino-oxazoles 1 was found to be the most potent antiviral compound. Following p.o. or s.c. administration to rats, the 14C-labeled 1 was quickly and completely absorbed. The TRA was eliminated mainly via the kidneys and the liver with half-lives between 32 and 42 h. The acute pharmacodynamic effects of 1 were decrease of blood pressure, bradycardia, and inhibition of both gastric emptying and acid secretion. On smooth muscles spasmolytic and alpha-anti-adrenergic actions were predominant. After single administration the following MTD's were determined: 30 (mouse), 20 (rat), 10 mg/kg i.v. (pig), and 500 (mouse, rat), greater than 100 mg/kg p.o. (pig), respectively. In a subchronic toxicity study in rats, oral doses of 1 between 15 and 240 mg/kg given daily for 4 weeks were tolerated without any severe alterations related to the drug.

[Determination of oxygen content: a comparison between the new Oxystat-Photometer and the Lex-O2-Con]

The Oxystat-photometer (Fa. Andos) is a new instrument for measuring of oxygen content and haemoglobin of blood. Using specific agents oxygen and haemoglobin can be registered in small cuvettes. The principle of measurement is photometry. Additionally O2-saturation can be calculated. In 139 experiments we checked the reliability of the Oxystat-photometer in comparison to the Lex-O2-Con (Lexington Instruments Corporation). High significance could be demonstrated (r = 0.96). There was a range from the control value below 5%. Following investigations using calculation, results could be confirmed.

[The effect of clonidine on the intrapulmonary right-to-left shunt in one-lung ventilation in the dog]

Many vasoactive drugs--vasoconstrictors as well as vasodilators--impair the efficiency of hypoxic pulmonary vasoconstriction (HPV) and may cause dangerous hypoxemia during one-lung ventilation (1-LV). The effect of clonidine, a widely used alpha 2-agonistic antihypertensive agent, on intrapulmonary right-to-left shunt (Qs/Qt) during 1-LV has not yet been studied. METHODS. Twenty anesthetized beagle dogs were instrumented with a 7F Swan-Ganz catheter and an arterial line. A left thoracotomy in the lateral position was performed and the left main bronchus was prepared for clamping. Intravenous clonidine (5 micrograms/kg) was administered to 10 dogs. Anesthesia was maintained with either thiopental and fentanyl or halothane (0.8 insp. vol%) and fentanyl. The ventilatory frequency (100% O2, tidal volume 150 ml/kg) was adjusted to obtain an end-expiratory CO2 of 4.5%. Each dog underwent the following experimental sequence: (1) baseline measurements with 2-LV; (2) 20 min 1-LV (left lung atelectasis was achieved by clamping the left main bronchus); and (3) 20 min 2-LV. After allowing 30 min for conversion from i.v. to halothane anesthesia or vice versa, the procedure was repeated (5 dogs in each group received first i.v. and 5 dogs first halothane anesthesia). RESULTS. Qs/Qt was slightly but not significantly higher under halothane anesthesia in both groups during 1-LV as well as 2-LV (Table 1). No differences existed between the halothane and i.v. groups with regard to arterial pO2 and cardiac index. In the control group (i.v. or halothane, n = 20) Qs/Qt increased during 1-LV from 10.8 +/- 2.8% (mean +/- S.D.) to 26.6 +/- 5.5%, and in the clonidine group (i.v. or halothane, n = 20) from 7.2 +/- 2.3% to 18.3 +/- 5.4%. These differences between the control and clonidine groups are significant (P less than 0.001) for 1-LV as well as 2-LV. Arterial pO2 during 1-LV was reduced less in the clonidine group (573 +/- 48 to 390 +/- 99 mmHg) than in the control group (550 +/- 44 to 323 +/- 94 mmHg) (P less than 0.05). During 1-LV no significant differences between the two groups could be detected with regard to pulmonary artery pressure, mixed-venous pO2, pCO2, and pH. Heart rate, cardiac index, and oxygen uptake were significantly lower and arteriovenous O2 difference was significantly greater in the clonidine group, indicating better control of sympathoadrenergic activity under clonidine. CONCLUSIONS. We conclude that pretreatment with clonidine improves HPV during 1-LV. This effect of clonidine is probably due to reduced sympathetic nervous system activity.

[Propofol for induction and maintenance of anesthesia during heart surgery. Results of pharmacological studies in man]

Numerous reports have concluded that propofol is suitable for maintenance of anesthesia by continuous infusion. The aim of this study was to evaluate the use of propofol and fentanyl for coronary bypass surgery in patients with good left ventricular function. The effects of this anesthetic combination on quality of anesthesia, hemodynamic status, and endocrine and metabolic responses were assessed. Postoperative recovery and side effects were also noted. The effects were compared with those of a standard method using etomidate, midazolam, and fentanyl. METHODS. Twenty patients who presented for aortocoronary bypass surgery (NYHA class II-III) were randomly allocated to one of two groups: propofol-fentanyl (group A) or etomidate-midazolam-fentanyl (group B). In each patient the dosage of the drugs was adjusted to obtain the optimum responses during induction and maintenance. RESULTS. Propofol in combination with fentanyl diminished mean arterial pressure (-28.7%) and heart rate (-17.3%) when used for induction in patients with ischemic heart disease, even in low doses and with slow administration. In 5 of the 10 patients it was impossible to prevent a critical fall in coronary perfusion without active intervention. However, during maintenance anesthesia, stable circulatory parameters were obtained with both drug regimens. Clinical signs thought to reflect myocardial ischemia were not observed. In both groups reductions in basal and stimulated catecholamine secretion were demonstrated. Similarly, perioperative cortisol secretion was reduced with both techniques. Despite all the complicated metabolic inhibitory effects seen, preoperative hormonal levels were restored within 1 h of the end of anesthesia. The magnitude and duration of the metabolic changes were found to be related to the duration of surgery. There was no evidence of non-homogeneous tissue perfusion as assessed by increases in lactate concentration, cardiac ischemia, or liver dysfunction in any of the patients. There were no postoperative complications in either group, but the return of consciousness, adequate spontaneous ventilation, and psychomotor activity was more rapid in the propofol patients. CONCLUSION. In summary, it can be concluded that a propofol infusion technique positively enhances the recovery period after cardiac surgery and provides good control during anesthesia. However, the use of propofolfentanyl for induction of anesthesia in patients with limited coronary perfusion is not recommended because of its hypotensive effect.

Anaesthetic problems in ex situ resection of the liver

Ex-situ resection of the liver is a new surgical technique for treatment of liver tumours not amenable to conventional surgery. This paper describes the cardiovascular and metabolic changes that occurred in nine consecutive such patients. No severe haemodynamic or pulmonary complications occurred. Specific problems were encountered during the prolonged anhepatic period, which lasted an average of 5.96 (SD 1.46) hours. Significant metabolic and coagulation disorders occurred 2 to 3 hours after hepatectomy because of complete loss of hepatic function. The predominant findings during the anhepatic period were hypoglycaemia and severe metabolic acidosis, mainly from increased levels of lactic acid. Exogenous administration of dextrose 5% at an average rate of 188 ml/hour was necessary to maintain normoglycaemia, while correction of metabolic acidosis required 403 (SD 159.79) mmol of sodium bicarbonate, supplemented by hyperventilation. Tris-hydroxymethylaminomethane was used when sodium overload was thought to be a problem. There was a marked decrease of Factor V and fibrinogen, a moderate thrombocytopenia and fibrinolysis. The severity of these alterations was dependent on the duration of the anhepatic period and the primary function of the re-implanted liver.

[Use of calcium carbonate (CaCO3) as phosphate binder in dialysis patients in long-term follow-up over 3 years]

In 26 dialysis patients (age 46 +/- 47.8 years, dialysis 20.1 +/- 57 months) calcium carbonate was introduced to phosphate reduction for 3 years. The use of CaCO3 (4.4-9 g/d) for 9 months did reduce the phosphate level from 2.51 to 1.51 mmol/l in 77% of the patients and increase the calcium from 2.23 to 2.47 mmol/l. The long-term use use up to 3 years did'nt reduce the phosphate level effectively (mean value 2.24 mmol/l). In 77% of the patients a progression and in 42% new calcifications could be observed. The percentage of patients with soft tissue calcification within the 3-year CaCO3 therapy was increased from 43% to 67%. Therefore, CaCO3 alone in unsuitable for long-term use as phosphate binder in dialysis patients.

[Ex situ surgery of the liver--anesthesiologic management]

In a 40-year old patient multiple liver tumours that were otherwise regarded as irresectable were removed in an ex situ operation--according to the authors' knowledge for the first time in a human. After protective perfusion with a hypothermic HTK solution hepatectomy was performed. After extirpation of the tumours ex situ, the residual liver was re-implanted. The total operation time was 13 h 50 min, the anhepatic period lasted for 6 h 9 min. During the anhepatic period a venous bypass shunted the blood from the a femoral and the portal vein to an axillary vein. Considerable blood loss was balanced by the transfusion of 26 units of banked blood. Severe disturbances of blood coagulation could be avoided by early substitution with fresh frozen plasma, platelets and fresh blood. The long anhepatic phase caused an acidosis that required the application of 330 mVal NaHCC3. In the discussion the necessity for an aggressive intraoperative monitoring of haemodynamic and laboratory parameters is emphasized.

[Dynamics of amino acid and protein metabolism of laying hens after the administration of 15N-labeled wheat protein. 8. 15N-labeling of nitrogen and 15N incorporation into the amino acids of the liver]

Over 4 days 12 colostomized laying hens received, together with the ration, 36 g wheat with 14.37 atom-% 15N excess (15N'), The basic amino acids were nearly equally labelled. Three animals each were butchered after 12 h, 36 h, 60 h, and 108 h after the last 15N' application. Emission spectrometric determination of 15N' in the liver and in the amino acids was carried out. In addition, atom-% 15N' was determined in the free amino acids and the peptides. The labelling in the liver 12 h after the last 15N' application amounted to 1.75 atom-% 15N' and decreased after 108 h to 0.81 atom-% 15N'. The average TCA precipitable 15N' quota in the total 15N' amounted to 81.4% and was nearly identical at all measuring times. The arginine 15N' amount in the liver was twice as high as that of lysine 15N'. In dependence on the period of time after the last 15N' application the decrease in the labelling of the free arginine is considerable in comparison to free lysine. At the first measuring time (12 h) it was 1.69 atom-% 15N' and at the last one (108 h) 0.57 atom-% 15N'. Based on the results of 15N' labelling of the peptides in the liver further, more detailed series of experiments for studies of the peptide metabolism in the liver should be carried out.

[Ex situ operation on the liver. A new possibility in liver surgery]

A method for an ex situ operation of the liver is presented with the example of such an operation in a 40-year-old patient. With this operation bilateral liver metastases of a leiomyosarcoma--which were otherwise regarded as irresectable--were resected. Function of the liver after reimplantation was good. Liver protection was performed by perfusion with cardioplegic HTK-solution (Bretschneider). The techniques of liver ex- and implantation are based on the methods of liver transplantation. Extracorporal femoro-porto-axillary bypass for decompression of the inferior caval vein and portal vein was used throughout the anhepatic period of 6 h. It is supposed that the method described here--which according to the authors' knowledge has been performed for the first time in a patient--will open up new perspectives for the surgery of malignant and occasionally of benign tumors, if necessary also for other surgical liver diseases. As an additional possibility, in situ protection of the liver with consecutive operation of the bloodless liver in situ is discussed. This procedure will correspond for the most part to the ex situ technique described here.

[Dynamics of amino acid and protein metabolism of laying hens after administration of 15N-labeled wheat protein. 6. 15N incorporation into the contents and tissue of segments of the gastrointestinal tract and into the pancreas]

12 colostomized laying hens received, together with a conventional feed ration, 15N labelled wheat with a 15N excess (15N') of 14.37 atom-% over 4 days. 3 animals each were butchered after 12 h, 36 h, 60 h and 108 h after the last 15N' application and, apart from various organs, the contents and the tissue of the gastro-intestinal tract of each hen was divided into 3 fractions. TCA precipitation was carried out with the contents and the tissue of the 3 fractions. Nitrogen and its atom-% 15N' were determined in the supernatant and the precipitate. The 15N' amount in the contents of the crop and the stomachs, the small and large intestines is still considerable 12 h after the last 15N wheat feeding and still clearly detectable 108 h after it. The TCA precipitable amounts of 14N and 15N' of the contents of crop and stomach and that of the small intestine agree well; they are 75% and 50% resp. of the total N. The amount of atom-% 15N' of the contents of the small and large intestines remains the same up to 36 h after the last 15N' application and is higher at the following measuring points in the contents of the large intestine. A close correlation could be ascertained between the atom-% 15N' in the contents and tissue of the small and large intestines. The TCA soluble N quotas of both 14N and 15N' in the pancreas are higher than 50%.

[Dynamics of amino acid and protein metabolism of laying hens after administration of 15N-labeled wheat protein. 5. Incorporation of 15N into the blood fraction and its amino acids]

12 colostomized laying hens which received 15N labelled wheat over 4 days were butchered 12 h, 36 h, 60 h and 108 h (3 animals each) after the last 15N application. The intake of 15N excess (15N') from the wheat amounted to 540 mg 15N' during the application period. The 15N' in the blood plasma decreased after the last 15N' application from 0.76 atom-% to 0.55 atom-% after 108 h, the labelling of the corpuscular components at the same measuring points increased from 0.28 to 0.50 atom-% 15N'. 96.6% of the plasma 15N' and 93.8% of that in the corpuscles is precipitable in trichloric acetic acid. The atom-% 15N' of histidine in the total blood remained unchanged in dependence on the butchering time. The 15N amount in lysine and arginine and that in the non-basic amino acids decreased inconsiderably in the period between 12 h and 108 h after the last 15N' wheat feeding.

[Dynamics of amino acid and protein metabolism of laying hens after the administration of 15N-labeled wheat protein. 3. Incorporation of 15N into egg shell, egg white and egg yolk]

12 colostomized laying hybrids received a ration meeting their requirement of 15N labelled wheat with a 15N excess (15N') of 14.37 atom-% over 4 days. The 15N' of the total ration amounted to 4.47 atom-%. Each hen consumed 135 mg 15N' per day. On another 4 days the same rations with non labelled wheat were fed. The 12 hens laid 56 eggs during the 8 days of the experiment. They were divided into egg shell, white and yolk of egg. In addition, the protein of the white and yolk of egg was precipitated with trichloric acetic acid (TCA) and the nitrogen in these fractions was determined. On average of the 56 eggs, the N quota in the egg shell was 5.3%, in the white of egg 49.1% and in the yolk 45.6%. The atom-% 15N' in the shells of the eggs laid on the first day of the experiment was on average 0.21, whereas only 0.03 and 0.02 atom-% 15N' resp. could be detected in the white and yolks of the eggs. On the first day after the last 15N application the atom-% 15N' in the egg shell and the white of egg was highest and amounted to 2.33 and 2.43 atom-% resp. The highest value of 1.83 atom-% 15N' in the yolk was ascertained 3 days after the last 15N intake. The mean quota of TCA-precipitable N in the white of egg is 97.6% and in the yolk 94.4% of the respective total N. The atom-% 15N' in the non-protein N-compounds was higher than in the protein fractions.