Adrenal Vein Catecholamine Levels and Ratios: Reference Intervals Derived from Patients with Primary Aldosteronism.

Phaeochromocytoma localisation is generally reliably achieved with modern imaging techniques, particularly in sporadic cases. On occasion, however, there can be diagnostic doubt due to the presence of bilateral adrenal abnormalities, particularly in patients with mutations in genes predisposing them to the development of multiple phaeochromocytomas. In such cases, surgical intervention is ideally limited to large or functional lesions due to the long-term consequences associated with hypoadrenalism. Adrenal venous sampling (AVS) for catecholamines has been used in this situation to guide surgery, although there are few data available to support diagnostic thresholds. Retrospective analyses of AVS results from 2 centres were carried out. A total of 172 patients (88 men, 84 women) underwent AVS under cosyntropin stimulation for the diagnosis of established primary aldosteronism (PA) with measurement of adrenal and peripheral venous cortisol, aldosterone and catecholamines. Six patients (3 men, 3 women) with phaeochromocytoma underwent AVS for diagnostic purposes with subsequent histological confirmation. Reference intervals for the adrenal venous norepinephrine to epinephrine ratio were created from the PA group. Using the 97.5th centile (1.21 on the left, 1.04 on the right), the false negative rate in the phaeochromocytoma group was 0%. In conclusion, this study describes the largest dataset of adrenal venous catecholamine measurements and provides reference intervals in patients without phaeochromocytoma. This strengthens the certainty with which conclusions related to adrenal venous sampling for catecholamines can be drawn, acknowledging the procedure is not part of the routine diagnostic workup and is an adjunct for use only in difficult clinical cases.

A case of thyroid storm complicated by acute hepatitis due to propylthiouracil treatment.

UNLABELLED: A 57-year-old female presented 17 days after treatment with radioactive iodine (RAI) for difficult-to-control hyperthyroidism. She was febrile, had a sinus tachycardia, and was clinically thyrotoxic. Her thyroid function tests showed a suppressed TSH <0.02 mU/l, with free thyroxine (FT4) >75 pmol/l and total triiodothyronine (TT3) 6.0 nmol/l. She was diagnosed with thyroid storm and was managed with i.v. fluids, propylthiouracil (PTU) 200 mg four times a day, prednisolone 30 mg once daily and propanolol 10 mg three times a day. She gradually improved over 2 weeks and was discharged home on PTU with ß blockade. On clinic review 10 days later, it was noted that, although she was starting to feel better, she had grossly abnormal liver function (alanine transaminase (ALT) 852 U/l, bilirubin 46 µmol/l, alkaline phosphatase (ALP) 303 U/l, international normalized ratio (INR) 0.9, platelets 195×10(9)/l). She was still mildly thyrotoxic (TSH <0.02 mU/l, FT4 31 pmol/l, TT3 1.3 nmol/l). She was diagnosed with acute hepatitis secondary to treatment with PTU. Ultrasound showed mild hepatic steatosis. PTU was stopped and she was managed with fluids and prednisolone 60 mg once daily and continued ß blockade. Her liver function gradually improved over 10 days (bilirubin 9 µmol/l, ALT 164 U/l, ALP 195 U/l, INR 0.9, platelets 323×10(9)/l) with conservative management and had normalised by clinic review 3 weeks later. This case highlights the potentially fatal, but rare, complications associated with both RAI and PTU, namely, thyroid storm and acute hepatitis respectively. LEARNING POINTS: Thyroid storm is an important, albeit rare, endocrinological emergency.Thyroid storm following RAI treatment is extremely rare.Management is with i.v. fluids, ß blockade, anti-thyroid drugs and steroids.High dose glucocorticoid steroids can block the peripheral conversion of T4 to active T3.Liver dysfunction, acute hepatitis and potential hepatic failure are significant adverse drug reactions known to occur with PTU treatment. Supervising clinicians should be vigilant for evidence of this developing and intervene accordingly.Clinicians need to be aware of possible interactions between regular paracetamol use and PTU in predisposing to liver impairment.

How 40 kilograms of fluid retention can be overlooked: two case reports.

INTRODUCTION: With a rising incidence of severe obesity in developed nations, heart failure, a well-recognised co-morbidity, is becoming more common. CASE PRESENTATION: We describe two recent patients encountered, a 64 year old and a 42 year old, who are both severely obese and presented with fluid retention of approximately 40 kilograms. Assessment revealed that the explanation of the gross clinical features were relatively subtle cardiac abnormalities. These cases illustrate how fluid retention in severe obesity can differ from that seen in 'traditional' heart failure in terms of clinical assessment and management. CONCLUSION: Severe obesity can result in insidious fluid retention, which can be easily overlooked until large volumes of fluid have accumulated. Cardiac abnormalities are usually found in these patients, but may be relatively subtle, leading to current debate in the definition and classification of heart failure. These scenarios are increasingly being encountered in clinical practice. Recognition, assessment and treatment of the 'clinical syndrome of heart failure' in severe obesity is often difficult.