Acute life-threatening presentation of vitamin D deficiency rickets

CONTEXT

Clinical manifestations of vitamin D deficiency rickets are widely described; however cardiorespiratory arrest is an extremely rare presentation.

OBJECTIVE

The aim of this paper is to present the symptoms of severe vitamin D deficiency rickets and to highlight the importance of vitamin D prophylaxis in infants.

RESULTS

We report a case of a 16-month-old infant who presented to emergency room with a stridor that evolved into a full cardiorespiratory arrest secondary to hypocalcemia. Medical history revealed that the infant was exclusively breastfed without vitamin D supplementation until the age of 10 months. Due to cultural habits, his diet was also grossly deficient in dairy products. Physical exam revealed clinical signs of rickets. Laboratory test showed severe hypocalcemia, elevated alkaline phosphatase, normal serum phosphorous, decreased 25(OH) cholecalciferol, increased intact parathyroid hormone level, and normal urine calcium excretion. The radiography of the wrist showed evidence of cupping, fraying, metaphyseal widening, and demineralization of the distal radial and ulnar metaphyses. The bone mineral density of the lumbar spine measured by dual x-ray absorptiometry showed a Z-score below -2 SD. His cardiorespiratory arrest secondary to hypocalcemia was therefore attributed to severe nutritional rickets.

CONCLUSION

Vitamin D deficiency rickets can be life threatening. Vitamin D supplementation is therefore crucial, especially in breastfed infants and some ethnic minorities (dark-skinned people, poor sun exposure), more at risk for developing severe rickets if not supplemented.

The role of posterior fossa decompression in acute cerebellitis

BACKGROUND

We present two cases of children who were diagnosed with cerebellitis with acute cerebellar swelling. This rare pathology is potentially fatal, and no clear treatment guidelines are described in the literature.

DISCUSSION

Considering our experience, we discuss the different therapeutic strategies and propose aggressive surgical measures consisting of external ventricular drainage and posterior fossa decompression in case of failure of early response to medical treatment to limit secondary cerebellar and brainstem lesions.

[Management of pediatric septic shock]

Septic shock is a frequent admission cause in intensive care unit. In spite of the important progresses in the understanding of his physiopathology, mortality due to septic shock is about 20%. Recently, it has been demonstrated that an early goal-directed therapy permitted to improve the patient prognosis. With a good hemodynamic management and early antibiotherapy, mortality could be reduced.

Ventilation non invasive en réanimation pédiatrique : un début d’expérience

Non-invasive ventilation in pressure support (NIV) is well described in the adult and child over 5 years. However, its use in children less than 1 year of age remains anecdotal. We report our preliminary experience with the use of NIV in six children aged from 5 days to 10 months. NIV was delivered with a flow generator (VPAP IIST, Resmed Ltd, North Ryde, NSW, Australia) in association with specific tubings and a nasal mask. The use of NIV resulted in a significant decrease of both the respiratory rate (from 53 to 39 breaths per min, p < 0.01) and the PvCO(2) (from 9.33 to 6.28 kPa, p < 0.01). These results show that NIV can be used in children under 1 year of age with improvement of physiological parameters.

Imaging of cavitary necrosis in complicated childhood pneumonia

The aim of this study was to illustrate the chest radiographs (CR) and CT imaging features and sequential findings of cavitary necrosis in complicated childhood pneumonia. Among 30 children admitted in the Pediatric Intensive Care Unit for persistent or progressive pneumonia, respiratory distress or sepsis despite adequate antibiotic therapy, a study group of 9 children (5 girls and 4 boys; mean age 4 years) who had the radiographic features and CT criteria for cavitary necrosis complicated pneumonia was identified. The pathogens identified were Streptococcus pneumoniae( n=4), Aspergillus( n=2), Legionella( n=1), and Staphylococcus aureus( n=1). Sequential CR and CT scans were retrospectively reviewed. Follow-up CR and CT were evaluated for persistent abnormalities. Chest radiographs showed consolidations in 8 of the 9 patients. On CT examination, cavitary necrosis was localized to 1 lobe in 2 patients and 7 patients showed multilobar or bilateral areas of cavitary necrosis. In 3 patients of 9, the cavitary necrosis was initially shown on CT and visualization by CR was delayed by a time span varying from 5 to 9 days. In all patients with cavities, a mean number of five cavities were seen on antero-posterior CR, contrasting with the multiple cavities seen on CT. Parapneumonic effusions were shown by CR in 3 patients and in 5 patients by CT. Bronchopleural fistulae were demonstrated by CT alone ( n=3). No purulent pericarditis was demonstrated. The CT scan displayed persistent residual pneumatoceles of the left lower lobe in 2 patients. Computed tomography is able to define a more specific pattern of abnormalities than conventional CR in children with necrotizing pneumonia and allows an earlier diagnosis of this rapidly progressing condition. Lung necrosis and cavitation may also be associated with Aspergillus or Legionella pneumonia in the pediatric population.

Reliable tidal volume estimates at the airway opening with an infant monitor during high-frequency oscillatory ventilation

OBJECTIVE

To assess the suitability of a hot-wire anemometer infant monitoring system (Florian, Acutronic Medical Systems AG, Hirzel, Switzerland) for measuring flow and tidal volume (Vt) proximal to the endotracheal tube during high-frequency oscillatory ventilation.

DESIGN

In vitro model study.

SETTING

Respiratory research laboratory.

SUBJECT

In vitro lung model simulating moderate to severe respiratory distress.

INTERVENTION

The lung model was ventilated with a SensorMedics 3100A ventilator. Vt was recorded from the monitor display (Vt-disp) and compared with the gold standard (Vt-adiab), which was calculated using the adiabatic gas equation from pressure changes inside the model.

MEASUREMENTS AND MAIN RESULTS

A range of Vt (1-10 mL), frequencies (5-15 Hz), pressure amplitudes (10-90 cm H2O), inspiratory times (30% to 50%), and Fio2 (0.21-1.0) was used. Accuracy was determined by using modified Bland-Altman plots (95% limits of agreement). An exponential decrease in Vt was observed with increasing oscillatory frequency. Mean DeltaVt-disp was 0.6 mL (limits of agreement, -1.0 to 2.1) with a linear frequency dependence. Mean DeltaVt-disp was -0.2 mL (limits of agreement, -0.5 to 0.1) with increasing pressure amplitude and -0.2 mL (limits of agreement, -0.3 to -0.1) with increasing inspiratory time. Humidity and heating did not affect error, whereas increasing Fio2 from 0.21 to 1.0 increased mean error by 6.3% (+/-2.5%).

CONCLUSIONS

The Florian infant hot-wire flowmeter and monitoring system provides reliable measurements of Vt at the airway opening during high-frequency oscillatory ventilation when employed at frequencies of 8-13 Hz. The bedside application could improve monitoring of patients receiving high-frequency oscillatory ventilation, favor a better understanding of the physiologic consequences of different high-frequency oscillatory ventilation strategies, and therefore optimize treatment.

[Acute respiratory distress syndrome in children]

The acute respiratory distress syndrome (ARDS) encountered in a child may be either due to a primary lung infection or may be secondary to a systemic inflammatory response of varying origin. Therapy is based on: 1) the mechanical ventilation strategy aimed at maintaining the functional residual capacity by alveolar recruitment using positive end expiratory pressure and to limit secondary pulmonary lesions by using small tidal volumes, 2) prone positioning as soon as sufficient stability is achieved; 3) optimizing tissue oxygen delivery by cardiac support; 4) correction of any other organ dysfunction. If this conventional approach is not sufficient experimental therapies may be tempted given the vital risk. For instance inhaled nitric oxide and high frequency oscillation ventilation may be a valuable support. Newer techniques, such as partial liquid ventilation, are being developed and could become useful therapeutic options. After the acute phase a close medical follow-up is mandatory. Because of the possibility of a chronic respiratory insufficiency with negative consequences on the right ventricular function, these patients may need long term oxygen therapy and diuretics. Cardiac echography helps orientation in maintaining or discontinuing this long term therapy by estimating the arterial pulmonary pressure.

Nitric oxide added to the sweep gas infusion reduces local clotting formation in adult blood oxygenators

Nitric oxide (NO) is an inhibitor of platelet aggregation. We analyzed the effect of direct infusion of NO into adult blood oxygenators on local clot formation. Nonheparinized calves in a control group (n = 3) and NO group (n = 4) were connected to a jugulocarotid cardiopulmonary bypass (CPB; centrifugal pump) for 6 hours. The venous line and pumphead were heparin coated, whereas the oxygenator, the heat exchanger, and the arterial line were not. A total of 80 ppm of NO was mixed with the sweep gas infusion in the NO group. The pressure gradient through the oxygenator (delta<gd>P.Ox.) was monitored, and its evolution was compared between groups. Oxygenators membranes were analyzed and photographed, allowing for calculation of the percentage of surface area covered with clots by using a computer image analysis program. The delta<gd>P.Ox. reached a plateau of 193 +/- 26% of the basal value in the NO group after 120 minutes, whereas a similar plateau of 202 +/- 22% was reached after only 20 minutes in the control group (p < 0.05). The surface area of the oxygenator covered with clots was significantly reduced in the NO group (0.54 +/- 0.41%) compared with the control group (5.78 +/- 3.80%, p < 0.05). However, general coagulation parameters were not modified by local NO administration. The activated coagulation time remained stable between 110 and 150 seconds in both groups (p = not significant [ns]), and there were no differences in hematocrit, thrombin time, partial thromboplastin time, or fibrinogen between groups during the 6 hours of CPB. Thus, the mixed infusion of a continuous low dose of NO into adult oxygenators during prolonged CPB prevented local clot formation, whereas the general coagulation pattern remained unchanged.

Evaluation of physicochemical incompatibilities during parenteral drug administration in a paediatric intensive care unit

Patients in paediatric intensive care units (PICU) often receive numerous medications by the parenteral route. Frequently two or more drugs are delivered simultaneously through the same line and the risk of physicochemical incompatibilities is thus important. The objectives of this study were 1) to identify prospectively the combinations of injectable drugs administered in the PICU of our university hospital and 2) to analyze them according to information found in the literature. The data were collected by a pharmacist over a 30-day period and classified in three categories: compatible, incompatible and undocumented. Nineteen patients were included in the study with a median age of 3.2 years. The mean number (+/- SD) of injectable drugs per patient and per day was 6.5 (+/- 2.8), for a total of 26 drugs and 7 solutes. 64 combinations of drugs were observed with 2 (31.3%), 3 (45.3%), 4 (10.9%) or 5 (12.5%) drugs. 81 drug-drug and 94 drug-solute combinations were recorded. Among these, 151 (86.3%) were compatible, 6 (3.4%) incompatible and 18 (10.3%) undocumented. The incompatibilities included furosemide (Lasix), a drug in alkaline solution and Vamina-Glucose, a total parenteral nutrition solution. No clinical consequences resulting from drug incompatibilities were shown in this study. We suggest that in vitro compatibility tests on standard drug combinations, as well as a training program for nurses on drug incompatibility problems would sensitively increase the security of parenteral drug administration.

In vitro assessment of an ultrasonic flowmeter for use in ventilated infants

An ultrasonic flowmeter could be advantageous over a differential pressure pneumotachograph having a constant error in varying conditions. The in vitro accuracy of ultrasonic tidal volume (VT) estimates for ventilated infants were evaluated. Flow linearity and frequency response were tested, as was the influence of humidity and oxygen content on the accuracy of VT estimates. The linearity was within the 5% limits between -350 and 350 mL x sec(-1) and was not affected by the presence of an endotracheal tube (ET). The frequency response was flat and unaffected by an ET up to 4.5 Hz. The VT in the range 7-100 mL, in air showed a mean error of 0.1% (95% confidence interval (CI) -0.2-0.4%) with a maximum and minimum of 6.5 and -3.5% respectively. Humidity did not affect accuracy. After calibration in air, the maximal mean error for measurements in pure oxygen was 3.0% (95% CI 1.9-4.1%). Repeated measurements over 5.5 h had a mean error of 0.4% (95% CI -0.7-0.1%). The in vitro evaluation of an ultrasonic flowmeter showed stable accuracy in mechanical ventilation conditions. Changing connection geometry and oxygen content did not increase the error to a clinically relevant degree. The flowmeter could therefore be a better alternative than the pneumotachograph for ventilated infants.

[Carbon monoxide poisoning in children: never trivialize]

The risks linked to tissular hypoxemia after carbon monoxide (CO) poisoning are well known. Unawareness of CO exposure and of its complex pathophysiology may delay appropriate treatment and lead to long term neuropsychological sequelae. We report two cases of children treated in our institution and review the main issues regarding the optimal management. A high index of suspicion for carbon monoxide poisoning when dealing with an unclear neurological clinical presentation is mandatory. Classical therapy with normobaric 100% oxygen has to be instaured immediately. Hyperbaric oxygen therapy must be considered when anamnestic symptoms or clinical signs suggest neurological involvement even when carboxyhemoglobin values are low or already normalized.

Long-term effects of neonatal hypoglycemia on brain growth and psychomotor development in small-for-gestational-age preterm infants

OBJECTIVE

To investigate the effects of neonatal hypoglycemia on physical growth and neurocognitive function.

STUDY DESIGN

A systematic detection of hypoglycemia (<2.6 mmol/L or 47 mg/dL) was carried out in 85 small-for-gestational-age preterm neonates. Prospective serial evaluations of physical growth and psychomotor development were performed. Retrospectively, infants were grouped according to their glycemic status.

RESULTS

The incidence of hypoglycemia was 72.9%. Infants with repeated episodes of hypoglycemia had significantly reduced head circumferences and lower scores in specific psychometric tests at 3.5 years of age. Hypoglycemia also caused reduced head circumferences at 18 months and lower psychometric scores at 5 years of age. Infants with moderate recurrent hypoglycemia had lower scores at 3.5 and 5 years of age compared with the group of infants who had 1 single severe hypoglycemic episode.

CONCLUSION

Recurrent episodes of hypoglycemia were strongly correlated with persistent neurodevelopmental and physical growth deficits until 5 years of age. Recurrent hypoglycemia also was a more predictable factor for long-term effects than the severity of a single hypoglycemic episode. Therefore repetitive blood glucose monitoring and rapid treatment even for mild hypoglycemia are recommended for small-for-gestational-age infants in the neonatal period.

Evaluation of nurses' errors associated in the preparation and administration of medication in a pediatric intensive care unit

The objectives of this study were to determine the frequency and the types of errors which occur regarding the preparation and the administration of medication and to identify the main causes of these errors in a pediatric intensive care unit (PICU) at the University Hospital in Lausanne (Switzerland). In this prospective study, based on the observation of nurses' activities, the data were collected over a period of 10 weeks. The error classification was based on the American Society of Hospital Pharmacy (ASHP) definitions. The frequency of errors was calculated as the sum of all noted errors divided by the total administered drugs, plus the sum of all omitted drugs, multiplied by 100. The sum of all given doses plus all omitted doses gives the 'total opportunity for errors'. This total was 275 and the total frequency of errors was 26.9%. The most frequent errors were wrong-time errors (32.4%), wrong-administration-technique errors (32.4%) and preparation errors (23.0%). In relation with other studies conducted under comparable conditions, a lesser number of omissions and wrong-time errors were observed. On the contrary, administration-technique and dose-preparation errors were more frequent at our hospital. A program of systematic assistance and survey by professional pharmacists could improve the quality of the preparation and administration of medication in the PICU.

[Is the use of ribavirin aerosols in respiratory syncytial virus infections justified? Clinical and economic evaluation]

The controversy about the use of ribavirin aerosol for children at risk (cardiopathy, pneumopathy, premature and immunodeficient patients), in case of respiratory syncytial virus (RSV) infection, led us to stop its prescription in 1993 and study prospectively the patients admitted during the following winters.

METHODS

Criterias of inclusion for this study were those of the Committee on Infectious Diseases of the American Academy of Pediatrics concerning the use of ribavirin aerosol. Two cohorts of patients were studied: the first group included treated patients (ribavirin group: n = 22, ribavirin and support treatment: salbutamol aerosols, respiratory physiotherapy and oxygen-therapy; winters 1989-1990 to 1992-1993); the second group included patients with support treatment only (control group: n = 22; winters 1993-1994 and 1994-1995).

RESULTS

The clinical gravity score at admission (4.55 vs 5.23, P = 0.46) and the risk factor scores (3.05 vs 3.27, P = 0.69) of the two groups were identical. Results showed that the children of the ribavirin group stayed much longer in hospital (14.2 vs 8.2 days, P = 0.002) and in the intensive care unit (7.2 vs 0.2 days, P < 0.001) than those of the control group. More support treatment was necessary for the ribavirin group as regard respiratory physiotherapy (3.8 vs 2.7 sessions a day, P = 0.026), the duration of oxygen-therapy (7.3 vs 3.7 days, P = 0.030) and the number of children requiring respiratory assistance (4 vs 0 children, P = 0.116). Administration of ribavirin aerosols (480 US$ a dose) and the way in which such treatment was carried out meant high daily costs for the ribavirin group (1,076 vs 604 US$, P < 0.001). As hospitalization was longer for children treated with ribavirin, the global cost was therefore much higher (15,552 vs 5,156 US$, P < 0.001).

CONCLUSION

The antiviral effect of ribavirin is undeniable. However ribavirin is known to be the cause of severe bronchospasms (two cases in our study) and can also cause moderate and long term bronchospasms, aggravating therefore the clinical evolution of the disease. Our experience shows that administration of ribavirin aerosols in case of RSV infection of inferior respiratory airways seems not to be justified.

[Fatal double tracheo-esophageal vascular compression and neurofibromatosis]

BACKGROUND

Vascular rings are a classical cause of tracheal and esophagus compression. We report the case of such an abnormality in an infant with neurofibromatosis.

CASE REPORT

A 1 week-old male infant with a familial neurofibromatosis presented a stridor with severe respiratory distress. A vascular ring was demonstrated and operated on. The stridor persisted after surgery. A postoperative oesophagogram and tracheobronchoscopy showed an irregular compression of the oesophageal lumen, thought to be due to a residual extrinsic compression. Because the postoperative echocardiogram showed an extensive tumoral infiltration of both auricles, it was decided to not operate again the child. The postmortem examination revealed a disseminated neurofibromatosis infiltrating trachea, bronchi and also the wall of esophagus.

CONCLUSION

Persisting stridor and oesotracheal compression postoperatively requires search for another cause. Association of vascular ring and neurofibromatosis is probably not fortuitous.

Magnesium sulphate as an alternative and safe treatment for severe persistent pulmonary hypertension of the newborn

Eleven newborns admitted consecutively to the neonatal unit with respiratory failure and severe persistent pulmonary hypertension (PPHN) were included in a clinical trial to assess the efficacy of magnesium sulphate (MgSO4) in the treatment of PPHN. A loading dose of 200 mg/kg MgSO4 was given over 20 minutes, followed by a continuous infusion of 20-150 mg/kg/hour to obtain a magnesium blood concentration between 3.5 and 5.5 mmol/l. Mean (SD) duration of treatment was 75.5 (19.8) hours. No other vasodilatory drug was administered before or during the treatment and patients were not hyperventilated. Mean (SEM) PaO2 values significantly increased from 42.6 (8.8) before treatment to 70.3 (24.1) mm Hg after 24 hours, with no change in pH or PCO2. Oxygen index and alveolar-arterial oxygen gradient (A-aDO2) were significantly lower after 24 hours; respectively, 46.8 (15.2) to 28.0 (9.0) and 624.3 (11.3) to 590 (58) mm Hg. Mean airway pressure could be significantly reduced from 19.5 (3.1) to 13.9 (3.9) cm H2O after 72 hours. Mean ventilatory time support was 131 hours and mean total oxygen dependency 10 days. No systemic hypotension nor any other adverse effect were noted. All infants survived and the neurodevelopmental assessment was normal at 6 and 12 months of age. It is concluded that magnesium sulphate is a non-aggressive and low-cost treatment of short duration which is easy to apply. It may have a role in the various treatment of PPHN.

Acute fatal parainfectious cerebellar swelling in two children. A rare or an overlooked situation?

We report 2 previously healthy children who developed sudden unexpected respiratory arrest and brain death, during a presumed Epstein-Barr meningitis in one case and a multisystemic infection of unknown etiology in the other. Diffuse swelling of the cerebellum with upward transtentorial and downward tonsillar herniation, shown by brain CT-scan and MRI obtained after the acute event, was the most probable cause of death. Review of CT images performed before or at the onset of deterioration already showed discrete signs of early upward herniation of the cerebellar vermis that were initially overlooked. At autopsy in the first case, an acute lymphomonocytic meningoencephalitis with predominant involvement of the cerebellum was observed. Few similar cases were found in the literature, indicating that acute cerebellar swelling is either a very rare or an unrecognized, possibly preventable cause of death in acute inflammatory or non-inflammatory encephalopathies in children.

[Exertion syncope disclosing supravalvular mitral stenosis in an infant]

An infant with frequent upper airways infections presented syncopes during meals and weeping since the age of eleven months. Cardiac examination was always normal. At 14 months of age, an echocardiogram with colour Doppler demonstrated a severely stenotic isolated supramitral membrane with severe pulmonary hypertension. The membrane was immediately excised curing the malformation and suppressing definitively the syncopes, probably due to decreased cerebral blood flow during exertion. An echocardiogram should always be performed when syncopes remain unexplained in small children. It allows early diagnosis and treatment of congenital heart defects which do not have auscultatory findings especially those resulting in severe pulmonary venous obstruction.

Assessment of changes in body water by bioimpedance in acutely ill surgical patients

OBJECTIVE

To evaluate the relationship between changes in body bioelectrical impedance (BI) at 0.5, 50 and kHz and the changes in body weight, as an index of total body water changes, in acutely ill surgical patients during the rapid infusion of isotonic saline solution.

DESIGN

Prospective clinical study.

SETTING

Multidisciplinary surgical ICU in a university hospital.

PATIENTS

Twelve male patients treated for acute surgical illness (multiple trauma n = 5, major surgery n = 7).

SELECTION CRITERIA

stable cardiovascular parameters, normal cardiac function, signs of hypovolemia (CVP < or = 5 mmHg, urine output < 1 ml/kg x h).

INTERVENTIONS

After baseline measurements, a 60 min fluid challenge test was performed with normal saline solution, 0.25 ml/kg/min [corrected].

MEASUREMENTS AND RESULTS

Body weight (platform digital scale), total body impedance (four-surface electrode technique; measurements at 0.5, 50 and 100 kHz) and urine output. Fluid retention induced a progressive decrease in BI at 0.5, 50 and 100 kHz, but the changes were significant for BI 0.5 and BI 100 only, from 40 min after the beginning of the fluid therapy onwards. There was a significant negative correlation between changes in water retention and BI 0.5, with individual correlation coefficients ranging from -0.72 to 0.95 (p < 0.01-0.0001). The slopes of the regression lines indicated that for each kg of water change, there was a mean decrease in BI of 18 ohm, but a substantial inter-individual variability was noted.

CONCLUSION

BI measured at low frequency can represent a valuable index of acute changes in body water in a group of surgical patients but not in a given individual.

Accurate prediction of death by serial determination of galactose elimination capacity in primary biliary cirrhosis: a comparison with the Mayo model

We retrospectively analyzed the predictive accuracy of serial determinations of galactose elimination capacity in 61 patients with primary biliary cirrhosis. Death was predicted from the time that the regression line describing the decline in galactose elimination capacity vs. time intersected a value of 4 mg.min-1.kg-1. Thirty-one patients exhibited decreasing galactose elimination capacity; in 11 patients it remained stable and in 19 patients only one value was available. Among those patients with decreasing galactose elimination capacity, 10 died and three underwent liver transplantation; prediction of death was accurate to 7 +/- 19 mo. This criterion incorrectly predicted death in two patients with portal-vein thrombosis; otherwise, it did better than or as well as the Mayo clinic score. The latter was also tested on our patients and was found to adequately describe risk in yet another independent population of patients with primary biliary cirrhosis. Cox regression analysis selected only bilirubin and galactose elimination capacity, however, as independent predictors of death. We submit that serial determination of galactose elimination capacity in patients with primary biliary cirrhosis may be a useful adjunct to optimize the timing of liver transplantation and to evaluate new pharmacological treatment modalities of this disease.

Recurrence rate after discontinuation of long-term mebendazole therapy in alveolar echinococcosis (preliminary results)

The recurrence rate was investigated in 19 patients with non-resectable alveolar echinococcosis after discontinuation of a long-term therapy with mebendazole (average treatment 4.3 years). A control group consisted of 14 patients who underwent radical surgery and finished a course of prophylactic postoperative mebendazole treatment of 2 years. In the controls, no recurrence was observed after a post-therapy period averaging 3.5 years. In contrast, recurrence occurred in 7/19 patients (37%) with non-resectable alveolar echinococcosis an average of 1.6 years after discontinuation of the long-term mebendazole therapy. The absence of clinically detectable recurrence in the remaining 12 patients seems to be due either to spontaneous inactivation of alveolar echinococcosis preceding chemotherapy or too short post-therapy surveillance. The patients with recurrence responded favorably to reintroduction of chemotherapy. The data indicate that mebendazole therapy is parasitostatic rather than parasiticidal.

Effects of ursodeoxycholic acid treatment on nutrition and liver function in patients with cystic fibrosis and longstanding cholestasis

The prevalence of biliary and hepatic diseases is increasing in patients with cystic fibrosis as more of them reach adult life. There is no effective treatment or method of preventing cholestasis in cystic fibrosis, although beneficial effects have been ascribed to the tertiary bile acid, ursodeoxycholate, in other forms of chronic cholestasis. We evaluated prospectively the effects of a six month course of ursodeoxycholate (15-20 mg/kg per day) in eight, mostly adult, patients with cystic fibrosis and chronic cholestasis. Bile acid treatment improved inflammatory activity (average decrease in alanine aminotransferase, 60%, p less than 0.005) and cholestasis (alkaline phosphatase, 47%; p less than 0.01) in all patients. Quantitative liver function, measured by 45 minute sulphobromophthalein retention and by the 14C-aminopyrine breath test, improved in all patients while galactose elimination capacity showed a slight decrease. Patients' nutritional state improved as evidenced by a 1.8 kg weight gain and an increase in muscle mass suggested by a 26% increase in 24 hour urinary creatinine excretion. Steatorrhea was not affected by bile acid treatment. Ursodeoxycholic acid may be beneficial in the treatment of chronic cholestasis in cystic fibrosis by improving liver function and also the patient's nutritional state.

Albendazole kinetics in patients with echinococcosis: delayed absorption and impaired elimination in cholestasis

The pharmacokinetics of albendazole and its main metabolite, albendazole sulphoxide, have been examined after giving a single oral dose of 200 mg albendazole to 19 patients with either Echinococcus multilocularis or E. granulosus, 5 of whom had significant extrahepatic obstruction due to the underlying disease. The AUC of albendazole sulphoxide was increased in the latter patients (mean 122 mumols.h.l-1 compared to 17 mumols.h.l-1 in the non-obstructed group). Obstructed patients had delayed absorption, ka averaging 0.39 compared to 1.41 h-1 in non-obstructed patients. The corresponding elimination rate constant, ke was also prolonged, averaging 0.041 and 0.13 h-1 in the two groups, respectively. Four patients were restudied after complete or partial resolution of the cholestasis. The pharmacokinetic parameters in them had returned towards values comparable to those in the non-obstructed patients.

Pharmacokinetics of isradipine in patients with chronic liver disease

The pharmacokinetics of the dihydropyridine calcium antagonist isradipine has been examined in 8 healthy volunteers, 7 patients with non-cirrhotic chronic liver disease (CLD), and 8 patients with biopsy-proven cirrhosis (CIR). Isradipine was simultaneously given orally (12C 5 mg) and i.v. (13C 1 mg). Systemic availability was significantly increased from 17% to 16% in controls and CLD, respectively, to 37% in CIR. The corresponding systemic clearances averaged 1.1, 0.9 and 0.6 l.min-1, the reduction in cirrhotics being significant. Both aminopyrine demethylation capacity, a measure of hepatic microsomal function, and indocyanine green disappearance, a measure of hepatic perfusion, were correlated with the reduction in systemic clearance, and the reduction in oral clearance was correlated with the reciprocal of the serum bile acid concentration. The loss of first-pass extraction should be considered when this calcium antagonist is given perorally in patients with hepatic cirrhosis.

Therapeutic monitoring of albendazole: a high-performance liquid chromatography method for determination of its active metabolite albendazole sulfoxide

A sensitive and specific reversed-phase high-performance liquid chromatography (HPLC) method is described for the quantitative determination of albendazole sulfoxide (ASOX); since albendazole sulfone (ASON) appears only in small amounts and albendazole (ABZ) normally does not appear in human plasma, only a qualitative determination of ASON and ABZ was made in human plasma. Plasma samples were extracted three times using ethylacetate and petroleum benzine; this yielded optically clear samples which after evaporation were dissolved in the HPLC solvent and injected onto an RP-C18 column, with ultraviolet detection at 290 nm. The detection limit of the main metabolite ASOX was 50 nM and that of ASON was 100 nM. The intraday coefficient of variation for ASOX was 3.3% at a concentration of 2.2 microM, and the interday coefficients of variation were 14.5, 7.3, and 9.1% at ASOX concentrations of 0.5, 2.5, and 5.0 microM, respectively. Calibration was linear in a concentration range of 0.05-12 microM for ASOX and 0.1-8 microM for ASON, respectively. Pharmacokinetic data of a patient with echinococcosis are presented.

Albendazole treatment of echinococcosis in humans: effects on microsomal metabolism and drug tolerance

We prospectively studied the effect of albendazole on microsomal reserve and on first-pass activation to albendazole sulfoxide in patients with hydatid disease. An aminopyrine breath test was performed in 12 patients while they were receiving albendazole treatment and while they were not. Excretion of 14CO2 in breath averaged 0.70%.kg.mmol-1 +/- 0.20%.kg.mmol-1 without treatment and 0.54%.kg.mmol-1 +/- 0.14%.kg.mmol-1 with treatment (p less than 0.005). Plasma levels of albendazole sulfoxide were measured 4 hours after the morning dose during the first and second half of the 4-week treatment cycles. In nine of the 12 patients albendazole sulfoxide levels decreased during the second half of the cycle by an average of 0.84 +/- 0.76 mumol/L (p less than 0.02). Transaminase levels increased in 10 of the 12 patients during long-term albendazole treatment, and major side effects, including hepatotoxicity, neutropenia, and alopecia, were observed in three patients. We conclude that albendazole partially inhibits microsomal enzyme function but induces its own metabolism. Hepatotoxicity and other possible severe side effects necessitate close therapeutic monitoring of patients who are given albendazole.

Effect of intravenous fructose on the P-31 MR spectrum of the liver: dose response in healthy volunteers

Dynamic phosphorus-31 magnetic resonance (MR) spectroscopy of the liver after intravenous administration of fructose has been suggested as a test of liver function. To establish dose-response curves of the phosphorus metabolites in the normal human liver, each of four healthy volunteers was given two to four different fructose doses on separate days: 62.5, 125, 250, 375, or 500 mg per kilogram of body weight. P-31 MR spectra of the liver were acquired with a 2-T whole-body magnetic, both before and after fructose administration, at 2.5-minute intervals over at least 30 minutes. The fructose load caused a significant, linearly dose-dependent accumulation of phosphomonoesters (r = .72, P less than .01) and a decrease in inorganic phosphate (r = .78, P less than .005) and adenosine triphosphate (r = .73, P less than .01). On the basis of these experiments, dynamic P-31 MR spectroscopy seems promising in the assessment of liver function.

Biliary obstruction dissipates bioelectric sinusoidal-canalicular barrier without altering taurocholate uptake

To study immediate events during extrahepatic cholestasis, we investigated the effect of short-term biliary obstruction on the bioelectrical sinusoidal-canalicular barrier in the rat using molecular weight-matched uncharged and negatively charged inert solute pairs. The bioelectrical barrier averaged -22 +/- 5 and -18 +/- 4 mV (NS) using the pair carboxy-/methoxyinulin and ferrocyanide/sucrose, respectively. After a 20-min biliary obstruction both decreased by 61 and 11%, respectively, but only the large molecular weight pair (the inulins) returned to base line after release of the obstruction. Inert solute clearances were increased after short biliary obstruction depending on molecular size and negative charge (ferrocyanide greater than sucrose greater than carboxyinulin greater than inulin), suggesting that both permeability and bioelectrical barriers were affected by obstruction. The hepatic extraction in vivo of a passively transported drug not excreted into bile (D-propranolol) was not affected by obstruction, whereas that of an actively transported drug (glycocholate) decreased from 66 +/- 8 to 41 +/- 20% during biliary obstruction (P less than 0.01). Unidirectional transfer of glycocholate was not affected by short-term biliary obstruction in the situ perfused rat liver; however, 2 min after [14C]glycocholate administration, increased return was observed in hepatic venous effluent in obstructed animals. Our findings demonstrate a loss of the bioelectrical barrier immediately after short-term biliary obstruction. Decreased hepatic extraction in the view of unaltered sinusoidal uptake demonstrates regurgitation of bile into blood during short-term biliary obstruction.

Bile salts and hydrodynamics of bile formation

We report a novel method to assess bile secretory pressure using a Statham pressure transducer. The studies were performed in vivo in male Sprague-Dawley rats under pentobarbital anesthesia. Maximal secretory pressure averaged 21.8 +/- 1.1 (S.D.) cmH2O. The bile accumulated after 10 min of obstruction was 7.7 +/- 2.8 microliters.g-1; assuming a basal biliary dead space of 2.3 microliters.g-1, the distended capacity of the biliary tree averaged 10 microliters.g-1. The small volume of the strain gauge permitted calculation of compliance of the biliary tree which averaged 0.35 +/- 0.12 microliters.cmH2O-1.g-1. Stimulation of bile flow by bile salts reduced the time required to reach maximal bile secretory pressure. Taurocholate but not taurodehydrocholate decreased maximal secretory pressure within minutes, the pressure-time curves showing a new equilibrium between bile formation and regurgitation forces. Both bile flow and bile salt recoveries were decreased by taurocholate but not by taurodehydrocholate. Taurocholate decreased biliary compliance while taurodehydrocholate had no effect. This provides further evidence that taurocholate increases the biliary permeability and suggests that this bile salt also affects the elastic properties of the biliary tree.

[The long-term course of 60 patients with alveolar echinococcosis in continuous therapy with mebendazole (1976-85)]

Since 1976 60 patients with inoperable alveolar echinococcosis caused by Echinococcus multilocularis were treated with high doses of mebendazole and examined at regular intervals prospectively according to our protocol regarding clinical course, liver function, morphology, immunologically and plasma mebendazole levels. The average duration of disease was 8(1-19) years, the average duration of chemotherapy was 4.25 (0.75-9) years. The long term results showed a correlation of the clinical course with the mean plasma mebendazole levels and the duration of chemotherapy, respectively. Death (n = 5) or transient progression of the disease process (n = 14) was observed primarily in patients with low plasma mebendazole levels in the early course and within the first two years of chemotherapy. Only 9 patients showed a decrease of the parasite mass. Immundiagnosis (total serum IgE and serum antibodies against Echinococcus antigen) gave some information with regard to therapy results, but only in the long-term course. The cumulative survival of the patients under study was 96% at 5 years and 84% at 10 years, respectively which is markedly higher compared to historical control series with a letality of greater than 90% within 10 years.