The Effect of Renal Replacement Therapy in a Patient with Mercaptopurine Toxicity: Time to Revise Guidelines.

INTRODUCTION: Mercaptopurine, a thiopurine, is used in various disorders of immune regulation, such as autoimmune hepatitis. Thiopurine metabolism is complex with risk for overdosing, especially when metabolism is impaired by liver dysfunction. Hepatotoxicity may be due to mercaptopurine overdose and is often reversible after prompt cessation of the drug. CASE PRESENTATION: Treatment of thiopurine toxicity is mainly supportive and literature on enhanced elimination by renal replacement therapy is ambiguous. CONCLUSION: In this case of thiopurine toxicity, a patient with autoimmune hepatitis presents with abdominal pain, nausea, vomiting, and diarrhea. We show in this case report that renal replacement therapy had no effect on total body clearance of mercaptopurine.

High tacrolimus blood concentrations early after lung transplantation and the risk of kidney injury.

PURPOSE: Lung transplant recipients often develop acute kidney injury (AKI) evolving into chronic kidney disease (CKD). The immunosuppressant tacrolimus might be associated with the emergence of AKI. We analyzed the development and recovery of kidney injury after lung transplantation and related AKI to whole-blood tacrolimus trough concentrations and other factors causing kidney injury. METHODS: We retrospectively studied kidney injury in 186 lung-transplantation patients at the UMC Utrecht between 2001 and 2011. Kidney function and whole-blood tacrolimus trough concentrations were determined from day 1 to 14 and at 1, 3, 6, and 12 months postoperative. Systemic inflammatory response syndrome (SIRS), septic shock, and nephrotoxic medications were evaluated as covariates for AKI. We analyzed liver injury and drug-drug interactions. RESULTS: AKI was present in 85 (46%) patients. Tacrolimus concentrations were supra-therapeutic in 135 of 186 patients (73%). AKI in the first week after transplantation was related to supra-therapeutic tacrolimus concentrations (OR 1.55; 95% CI 1.06-2.27), ≥3 other nephrotoxic drugs (OR 1.96; 95% CI 1.02-3.77), infection (OR 2.48; 95% CI 1.31-4.70), and cystic fibrosis (OR 2.17; 95% CI 1.16-4.06). Recovery rate of AKI was lower than expected (19%), and the cumulative incidence of severe CKD at 1 year was 15%. CONCLUSIONS: After lung transplantation, AKI is common and often evolves into severe CKD, which is a known cause of morbidity and mortality. Supra-therapeutic whole-blood tacrolimus trough concentrations are related to the early onset of AKI. Conscientious targeting tacrolimus blood concentrations might be vital in the early phase after lung transplantation. What is known about this subject? • Lung transplant recipients often develop acute kidney injury evolving into chronic kidney disease increasing both morbidity and mortality. • To date, the pathophysiology of kidney injury after lung transplantation has not been fully elucidated. • The immunosuppressant tacrolimus is difficult to dose, especially in the unstable clinical setting, and is nephrotoxic. WHAT THIS STUDY ADDS: • For the first time, supra-therapeutic whole-blood tacrolimus trough concentrations are related to the emergence of acute kidney injury in the first days after lung transplantation. • Supra-therapeutic whole-blood tacrolimus trough concentrations often occur early after lung transplantation. • AKI after lung transplantation shows low recovery rates.

[Attempted suicide with barbiturates purchased online]. / Tentamen suicidii met barbituraten van internet.

BACKGROUND: Barbiturate intoxication is potentially lethal. With the availability of the newer anticonvulsants the use of barbiturates in treating epilepsy has decreased significantly, with a concurrent decrease in the incidence of overdose with these medications. There have, however, been recent alarm signals from governmental sources concerning the increase in the Internet purchase of illegal medications, including barbiturates, for use in attempted suicide. CASE DESCRIPTION: Here we describe two patient cases involving barbiturate intoxication with amobarbital and thiopental, respectively. They had both obtained the barbiturates via the Internet. Both patients were comatose and showed signs of respiratory depression; one of them was also haemodynamically unstable. Both patients recovered fully following intensive supportive therapy. CONCLUSION: In patients with coma, respiratory depression, absence of brainstem reflexes and shock with no evident cause one should be aware of the possibility of barbiturate intoxication, even when there is no indication that these have been prescribed or that the patient has direct or indirect access to barbiturates. Prompt, optimal supportive therapy will give a good chance of full somatic recovery.

Pharmacokinetics and Toxicity of Tacrolimus Early After Heart and Lung Transplantation.

Annually, about 8000 heart and lung transplantations are successfully performed worldwide. However, morbidity and mortality still pose a major concern. Renal failure in heart and lung transplant recipients is an essential adverse cause of morbidity and mortality, often originating in the early postoperative phase. At this time of clinical instability, the kidneys are exposed to numerous nephrotoxic stimuli. Among these, tacrolimus toxicity plays an important role, and its pharmacokinetics may be significantly altered in this critical phase by fluctuating drug absorption, changed protein metabolism, anemia and (multi-) organ failure. Limited understanding of tacrolimus pharmacokinetics in these circumstances is hampering daily practice. Tacrolimus dose adjustments are generally based on whole blood trough levels, which widely vary early after transplantation. Moreover, whole blood trough levels are difficult to predict and are poorly related to the area under the concentration-time curve. Even within the therapeutic range, toxicity may occur. These shortcomings of tacrolimus monitoring may not hold for the unbound tacrolimus plasma concentrations, which may better reflect tacrolimus toxicity. This review focuses on posttransplant tacrolimus pharmacokinetics, discusses relevant factors influencing the unbound tacrolimus concentrations and tacrolimus (nephro-) toxicity in heart and lung transplantation patients.

Extracorporeal membrane oxygenation in the treatment of poisoned patients.

CONTEXT: Although extracorporeal membrane oxygenation (ECMO) was used in many patients following its introduction in 1972, most hospitals had abandoned this experimental treatment for adult patients. Recently, improvements in the ECMO circuitry rendered it more biocompatible. The surprisingly low mortality in patients with severe acute respiratory distress syndrome who were treated with ECMO in the influenza A/H1N1 pandemic of 2009 resurrected interest in ECMO in many intensive care units around the world. OBJECTIVES: This article reviews the different techniques of ECMO, the indications, contraindications and complications of its use, its role in poisoned patients and the ethics of its use. METHODS: We searched Pubmed, Toxnet, Cochrane database and Embase from 1966 to September 2012 using the search terms (''extracorporeal membrane oxygenation'', 'extracorporeal life support', 'ECMO', 'ECLS', 'assist-device', and 'intox*' or 'poison*'). These searches identified 242 papers of which 116 described ECMO in conditions other than intoxications or were reviews. In total 46 publications selected for this manuscript were case reports or case series involving poisoned patients. ECMO TECHNIQUES: Two types of ECMO are used: veno-venous ECMO (VV-ECMO) or veno-arterial ECMO (VA-ECMO). VV-ECMO is used for patients with severe ARDS to secure adequate oxygenation of the organs while protecting the lungs from harmful ventilation pressures or prolonged inspiratory fraction of oxygen. VA-ECMO can be used whenever the patient remains in shock despite adequate fluid resuscitation and is refractory to administration of inotropes and vasopressors. INDICATIONS: The organ support that can be applied with ECMO makes it especially useful in patients with severe poisoning as the clinical impact of the intoxication is often temporary; ECMO can be used as a 'bridge to recovery'. CONTRAINDICATIONS: Absolute contraindications are uncontrolled coagulopathy and severe intracranial bleeding, which precludes the use of anticoagulation therapy. Relative contraindications to ECMO include advanced age, severe irreversible brain injury, untreatable metastatic cancer, severe organ dysfunction (some suggest a Sequential Organ Failure Assessment (SOFA) score > 15), and high pressure positive pressure ventilation for more than 7 days. COMPLICATIONS: The most common complication of ECMO is either bleeding at the cannulation site (in VV-ECMO) or bleeding at the surgical entry site (in VA-ECMO). Overall bleeding complications currently occur in 10-36% patients, and intracranial haemorrhage is seen in up to 6% of patients. ECMO should be reserved, therefore, for the most severely ill poisoned patients with a high risk of death. ECMO in poisoned patients. There are no randomised trials of ECMO in poisoned patients with refractory shock or who have ARDS caused by an intoxication. VV-ECMO can be considered in patients with type l and ll respiratory failure. In patients with life-threatening haemodynamic instability, VA-ECMO can be considered when shock persists despite volume administration, inotropes and vasoconstrictors, and (sometimes) intra-aortic balloon counterpulsation. Typical examples include poisoning due to calcium channel antagonists, beta-blockers, tricyclic antidepressants, chloroquine and colchicine. ETHICS OF ECMO USE: It is only ethical to use such a costly intervention (£19,252 and US$ 31,000 per quality-adjusted life year) if the treatment has a real purpose such as a 'bridge to recovery', a 'bridge to transplant', or a 'bridge to permanent assist device' (in the case of persistent cardiac failure). CONCLUSIONS: In the last decade, ECMO equipment has improved considerably, rendering it more biocompatible, and it has been used more frequently as an assist device for patients needing oxygenation as well as circulatory support. ECMO is considered a good salvage therapy for patients who are severely poisoned with ARDS or refractory circulatory shock.

Spurious hypokalaemia and hypophosphataemia due to extreme hyperleukocytosis in a patient with a haematological malignancy.

Serious hyperleukocytosis can strongly affect laboratory results of potassium, phosphate and arterial oxygen tension. A 40-year-old woman is presented with an acute myeloid leukaemia and a strongly elevated leukocyte count (310 x 10(9)/L). Apart from this hyperleukocytosis, initial blood tests showed hypokalaemia, hypophosphataemia and serious hypoxaemia without any corresponding complaints. Blood sampled and transported on ice or directly analysed showed no electrolyte abnormalities and hypoxaemia. The observed discrepancy in laboratory results is probably due to the metabolic activity of the leukocytes in vitro. Spurious laboratory results can be a reason for incorrect decisions concerning additional diagnostics and treatment. In conclusion, hyperleukocytosis can cause pseudohypokalaemia, pseudohypophosphataemia and pseudohypoxaemia, which can be prevented by correct sampling and immediate analysis.

A breakthrough in cryosurgery.

Liver cryosurgery is one of the treatment options for unresectable liver metastases. Indications for the use of this treatment instead of classic surgery are bilobar disease, location of the tumor at an irresectable anatomic site, and comorbid conditions of the patient. Possible complications of cryosurgery are hemorrhage, coagulopathy, pneumonia, pleural effusion, abdominal abscess, and bile fistula. We describe a patient in whom a hepatobronchial fistula developed after cryosurgery. The patient had cryosurgery because of an unresectable liver metastasis in a Dukes' C rectal carcinoma. More details are given in the case report. To our knowledge, a hepatobronchial fistula as a complication of cryosurgery has never been reported. It therefore should be added to the list of possible cryosurgery complications.