Long Term Dialysis with Low-Calcium Solution (1.0 Mmol/L) in Capd: Effects on Bone Mineral Metabolism

Objective

Peritoneal dialysate solutions with conventionally high-calcium (Ca) concentrations (1.75 mmol/L) are now widely replaced by solutions with a lower, more physiological calcium content to prevent hypercalcemia in patients treated with oral calcium-containing phosphate binders and/or calcitriol. While there is still debate on how far the dialysate calcium should be lowered (1.25 mmol/L or less), little information is available concerning the effects of a long-term treatment with low-calcium solutions on secondary hyperparathyroidism and bone mineral metabolism in general.

Design

A prospective, randomized, controlled multicenter study to compare the effects of low-calcium (LCa, dialysate calcium 1.0 mmol/L) versus standard calcium dialysate solution (SCa, dialysate calcium 1.75 mmol/L)on bone mineral metabolism in continuous ambulatory peritoneal dialysis (CAPD) patients over 2 years of treatment.

Setting

Nephrology and dialysis units of primary and tertiary hospitals in Germany and Switzerland.

Patients

All CAPD patients in the participating centers between 18 and 80 years of age, stable on CAPD for at least 1 month, free of aluminum bone disease or prior parathyroidectomy were invited to enter the study. Sixty-four patients could be randomly allotted to LCa (n = 35) or SCa (n = 29) treatment in a 2-year protocol; 34 finished the study as planned.

Interventions

Calcium carbonate (CaCO3) was given as oral phosphate binder to maintain serum phosphate <2.0 mmol/L. If hypercalcemia supervened, CaCO3 was exchanged stepwise for aluminium hydroxide (AI(OH)3)’ until normocalcemia was obtained. Patients received calcitriol (0.25 μg/day per os) if parathyroid hormone (PTH) exceeded the upper limit of normal by a factor of 2 or more.

Main Outcome Measures

We assessed total and ionized serum calcium, phosphate, serum aluminum, alkaline phosphatase, osteocalcin, PTH (intact molecule), and phosphate binder intake at regular intervals. Measurements of bone mineral density and hand skeleton x-rays were obtained at the start and after 6 months and 2 years, respectively.

Results

With LCa, mean total and ionized serum calcium levels were within the normal range (total Ca: 2.0 2.6 mmol/L; ionized Ca: 1.19–1.32 mmol/L), but throughout the treatment period were significantly lower than with SCa. The incidence of hypercalcemia (>2.8 mmol/L) was three times higher in patients on SCa, despite the significantly higher amount of AI(OH)3 and less CaCO3 given in this group. In parallel, serum aluminum increased with SCa throughout the study, whereas it was slowly decreasing with LCa. Median PTH levels remained stable at about two times the upper limit of normal over the 2 years of study with LCa. However, 23% of the patients on LCa developed severe hyperparathyroidism, with PTH levels exceeding ten times the upper limit of normal compared to only 10.3% of the patients on SCa. With SCa, median PTH decreased towards near normal levels. Alkaline phosphatase and serum osteocalcin correlated positively with PTH levels. Bone mineral density was in the lower normal range in both groups a n d remained unchanged at the end of the study. Skeletal x-ray films showed only minor alterations in very few patients in both groups with no correlation to serum PTH or treatment modality.

Conclusion

In CAPD patients low-calcium dialysate solutions can be used successfully over prolonged periods of time with stable control of serum calcium. The risk of hypercalcemia resulting from calcium-containing phosphate binders and the need to use aluminum-containing phosphate binders is markedly diminished. However, there is a certain risk that severe secondary hyperparathyroidism with long-term LCa therapy will develop, even if normocalcemia is maintained. Thus, LCa dialysis requires closeand continuous monitoring of PTH and bone metabolism.

The PhaSeal® system: Impact of its use on workplace contamination and duration of chemotherapy preparation

Purpose. The primary objective of this study was to compare the levels of environmental contamination before and after the introduction of PhaSeal® (closed-system drug transfer device) in two hospital pharmacies. Our secondary objective was to assess the impact of the device on the duration of drug preparation compared to procedures involving the use of needles and syringes.

Methods. The study involved two French hospitals, which prepared antineoplastic chemotherapy using a biological safety cabinet and an isolator. Five skilled pharmacy technicians at each hospital prepared a total of 100 chemotherapy preparations using the standard procedure and 100 using the PhaSeal® system. To control for possible contamination occurring in the course of the procedure, we used fluorescein which becomes fluorescent when exposed to UV light. To reply the second objective, we timed the duration of the different steps of the manipulation.

Results. Our findings showed a major reduction in the contamination of the work environment when using the PhaSeal® system for drug preparation. Reduction rates higher than 93% were obtained, whatever the type of protection used. On the duration of preparation, our results indicate that this duration would be approximately 1 h longer for the preparation of 100 samples.

Conclusion. In conclusion, this study clearly establishes the benefit of using PhaSeal® for protecting the staff members who work with hazardous agents. It also indicates that the duration of drug preparation is not impacted by the use of the system.

[Lung metastases--can resection also be justified in synchronous liver metastasis?]

There is general agreement on the preconditions necessary for the resection of lung metastases: the primary tumor has to be resected completely, a local tumor recurrence as well as metastases in other organs have to be excluded. 5-year survival rate of patients operated under these criteria is said to be about 20 to 40% (number of own patients: 72; 5-year survival rate: 30.2%. Only in a few cases, however, lack of metastases in other organs is given. Often there are synchronic liver metastases. Local intraarterial chemotherapy doesn't put much burden on the patient, induces a decrease of liver metastases in 30% and a complete remission in a few cases, respectively. Between 1981 and 1987 we performed local chemotherapy of the liver in 575 patients. 110 patients showed lung metastases in the course of the treatment or during the aftercare period. In 8 patients we resected lung metastases occurring after remission of liver metastases. 7 patients died 11 to 28 months after the operation, 1 patient is still alive 16 months postoperatively.

[Cold struma nodule--enucleation or resection]

During 1969-1984 2,408 patients underwent thyroid surgery at the Dept. of General Surgery, Giessen University. In 72.5% cold nodules have been diagnosed. However, a cold nodule has been in less than 50% of all cases with cold nodules the causal indication for operation. Inspecting closely the whole thyroid gland, the operating surgeon removes the nodule with a segmental resection if there are no further regressions or suspicion of malignancy. This technique facilitates the histological detection of a possible highly differentiated carcinoma because of its invasion into the capsule.

[Spasticity treatment with spinal morphine or midazolam. In vitro experiments, animal studies and clinical studies on compatibility and effectiveness]

Recent pharmacological investigations have support the hypothesis that spinal modulation of nociception as well as motor coordination is related to the activity of spinal interneurons and that certain spinal transmitters are involved in the control of both regulatory systems. Opioids and benzodiazepines, i.e. endorphin- or GABA-induced mechanisms, may be of importance for spinal treatment of spasticity in the near future. In order to clinically evaluate the interactions of these spinal processes we performed in vitro-experiments, animal studies and clinical investigations on the compatibility and antispastic efficacy of spinally administered opiates and benzodiazepines. Preclinical studies on tissue- and CSF-tolerance of different benzodiazepines (pH, tonometry, turbidimetry, histological findings in animals) are in favour of midazolam, a water-soluble compound, which is active against pharmacologically induced spasms in animals (strychnine application in cats with chronical catheterization of the subarachnoid space) after lumbar intrathecal injection. Using an appropriate dosage of intrathecal midazolam selective blockade of spasticity of the hind legs may be demonstrated with integrated EMG. Clinical investigations (neurological assessment using rating scores for spasticity) in 16 patients, including a double-blind comparison of epidural morphine or midazolam, indicate that both drugs are effective against spinal spasticity of different origin. Efficacy of spinally applied agents depends on the severity of spasms and on the duration and extent of systemic pretreatment.

Perfluorocarbone (FDA 20) and Extracorporeal Circuit of Isolated Extremity Perfusion

The applicability of Fluosol DA 20 as a perfusion fluid was investigated in the isolated limb perfusion of 14 mongrel dogs and its performance compared with that of diluted blood. Control of perfusion parameters permitted a direct comparison of the two perfusion liquids. Muscle tissue, blood and perfusate were analyzed for pH, pO2, pCO2, O2 content, lactate, pyruvate, ATP and creatine phosphate. Due to given experimental conditions, the pH values of the perfusion liquid and muscle tissue were in a slightly acidic range. The oxygen uptake of the perfusion liquids and the oxygenation of tissue was satisfactory, the metabolism of the muscle tissue was not disrupted.

[Stroma-free hemoglobin solution and perfusion of isolated extremities]

Pyridoxylated stroma-free hemoglobin solution was compared to hemodiluted blood in extremity perfusion of mongrel dogs. pH-values in tissue and in perfusate as well as oxygen tension showed no significant difference, and oxygen supply to the periphery was sufficient. Measurement of lactate, pyruvate, ATP and CP demonstrated domination of aerobic metabolism. We proved that stroma-free hemoglobin solution ( SFHb -PLP) can substitute hemodiluted blood (Hk 18) in isolated extremity perfusion. Metabolic results were confirmed by histological examination where no tissue alterations could be found in the perfused extremity or the whole body system.

[Treatment and results in malleolar fractures]

The authors compared the therapy results of 100 conservatively treated malleolar fractures and 100 malleolar fractures operated upon with the therapy results of the malleolar fractures registered at the documentation centre of the A. O. (working association for osteosynthesis) in Bern. The comparison shows that after surgical treatment, the therapy periods are scarcely shorter than after conservative treatment, the therapy results, however, are significantly better. There is a smaller rate of complications and subjective troubles after surgical treatment. The results of clinical and X-ray check-up examinations were essentially better after surgical treatment than after conservative treatment. The ability of patients concerning their professional and private activities was less disturbed after surgical treatment.

Isolated extremity perfusion with DTIC. An experimental and clinical study

Dacarbazine (DTIC) was used for isolated perfusion of extremities in dogs and man. In the animal experiment perfusions with DTIC at dosages up to 100 mg per kg of extremity weight were well tolerated. The concentration of DTIC in the perfusate ranged from 70 to 400 micrograms/ml without evidence for formation of metabolites. Electron microscopy, performed 14 days later, revealed a decrease of glycogen in striated muscle cells. Vascular damage was not observed. Five patients with advanced malignant melanoma or soft tissue sarcoma of the extremities were treated by isolation perfusion with 75 to 133 mg DTIC per kg of extremity at 40 degrees C for 60 minutes. A tumor regression of at least 30% was observed.

Regional perfusion with cis-platinum and dacarbazine

In 22 patients isolated extremity perfusion with cis-platinum for treatment of malignant melanoma was performed; 18 had local metastastic disease (M. D. Anderson stages II and III A, B, AB) and four were stage I. A further five patients were submitted to isolated DTIC perfusion. DTIC-perfused tumors showed regression rates of 30%-80%, followed by recurrences within 4 months. After cis-platinum perfusion stage-III AB cases tended to show tumor recurrence within 4 months, while to date stage-III A and stage-II cases have reached disease-free survival times of 17 and 20 months respectively. While in DTIC perfusion the tissue temperature may range between 40 degrees and 41 degrees C, in cis-platinum perfusions 40 degrees C should not be exceeded; otherwise neural damage will occur.

Fluorescence-histochemical and electron-microscopical investigations in melanoma patients after isolated cytostatic perfusion

The effect of isolated cytostatic perfusion was determined in in-transit metastases from malignant melanomas at various times after therapy. Fluorescence-microscopically positive tumor cells (formalin-induced fluorescence) were regarded as viable and possibly capable of dividing. Most of the metastases examined showed fluorescent cells even after perfusion, and these were often found at characteristic sites within the metastases. Under the electron microscope, the cell damage was seen mainly in the nucleus, but also in the organelles of the cytoplasm. The source of cell damage might be multifactorial, and the cytostatic effect could not be clearly separated from the effect of hyperthermia or hypoxia.

[The delayed split-skin coverage--use and advantages]

In 119 patients a "delayed skin flap transplantation" was carried out after excision of malignant melanomas. The skin graft can be stored in a refrigerator at 4 degrees C up to two weeks without damage to the transplant. The transplantation may be accomplished at any time, but is usually due 3 to 4 days postoperatively. Advantages of this method are decreased risk of local infection, early mobilisation of the patient and generally good cosmetic results.

[Somatostatin in the medical treatment of fistula of the pancreas and the small intestine]

Somatostatin is a peptide hormone which inhibits the secretion of the growth hormone and certain gastrointestinal hormones. Its main effect is to reduce the gastric acid output and inhibit the exocrine function of the pancreas. It was therefore used as an adjuvant therapy in the conservative treatment of ten patients presenting with fistulas of the small intestine or pancreas. The treatment was successful in eight cases. The short halflife of the hormone makes continuous application of the somatostatin as important as the carrying on of the conservative treatment itself.

[Vertical and excentric stress in case of a defect on the fracture gap]

In order to compare the external fixator of the Arbeitsgemeinschaft für Osteosynthesefragen (AO) to different types of assembly of the Stuhler-Heise fixator (frame fixator, three-dimensional fixator, three-dimensional fixator with two screws of Schanz) with different spans (110, 140 and 190 mm), a vertical and excentric stress was exerted on a defect on the fracture gap. The comparable types of assembly of the AO fixator were lighter by 20% on an average. In two thirds of all assemblies, i.e. in 12 among 18 assemblies, the Stuhler-Heise device showed markedly better results of stability at the simulated fracture gap with respect to a vertical downward movement. In three assembly series there were identical results, in the other three series the AO device brought about better results. Under excentric stress, both fixator types showed considerable torsion movements from the horizontal line within the fracture gap. The differences between the two fixator systems found out for defects on the fracture gap will probably be significantly less important in case of compression osteosynthesis. This assumption will be verified by further examinations.

[New modifications in isolated extremity perfusion ]

Hyperthermic isolated extremity perfusion has been undertaken in 117 patients with advanced melanoma of the extremities from october 1979 to may 1981. Perfusion is indicated in cases above level III and tumor thickness above 1,5 mm. Among the cytostatic agents used were melphalane, melphalane and dactinomycin, nitrogen mustard/dactinomycin, as well as DTIC, cis-platinum and the combination of cis-platinum and dactinomycin. All cytostatics lead to tumor regression, as observed on tumors left in situ. Longterm results have yet to be awaited. While melphalane may be perfused at 42 degrees C, the cisplatinum perfused extremity should not be heated to above 40 degrees C because permanent neurological damage may be induced. For this reason maximal hyperthermia is reached before the cytostatic agent is introduced and has to be lowered when the drug is added.

Levels of Cis-Platinum in hyperthermic isolated perfusion

The Cis-platinum levels in isolated extremity perfusion were measured in dogs and man. We found that prolonged presence of Cis-platinum in the tissue is attributed to its strong and rapid binding to serum and tissue proteins. Protein binding follows the concentration gradient. Subsequent re-diffusion into the blood followed by urinary excretion was also noted.

[Investigation about the stability of a fixateur-externe using a new screw nail (author's transl)]

Since former investigations showed that the 4.5 mm Steinmann-nails hitherto were the weakest part of fixateur-externe systems, we developed a screw nail with a shank thickness of 7 mm and a thread identical to that of the cortical screw developed by the Arbeitsgemeinschaft für Osteosynthese (Workshop Society for Osteosynthesis). By conducting experiments with a metal alloy (square tube made of aluminium) in cadaver bones, the bending stress of a frame assembly R and of a three-dimensional assembly with 2 Schanz-screws Z2S was examined with 4.5 mm Steinmann-nails as well as with screw nails. The systems mounted with the new screw nails bent considerably less than the other systems. The improvement in stability achieved by screw nails is relatively more significant for the external frame fixator and in cases of a defect at the fracture gap than for the three dimensional fixateur externe with 2 Schanz-screws and in case of a compression at the fracture gap.

[Malignant sacrococcygeal teratoma in an adult]

Malignant sacrococcygeal teratoma is rare in adults. diagnosis is difficult when the tumour is presacral located. A 42-year-old female patient underwent rectum extirpation with resection of a malignant sacrococcygeal teratoma. Histological biopsy and clinical staging did not show whether the teratomas were malignant or not. These tumours have to be resected totally, when necessary together organs of the pelvic region.