Survey of hypercalcaemia and audit of further management with focus on primary hyperparathyroidism

R P Raghavan; K Gkastaris; V Chortis; W W Woltersdorf; K J Bradley

Background: Hypercalcaemia is independently associated with increased cardiovascular morbidity/mortality. It is a poor prognostic marker in malignancy. Best practice dictates further investigation of any high calcium values. Recognition of primary hyperparathyroidism (PHPT) is important for long term follow-up and management.

Aims: Survey of causes of hypercalcaemia in adults (>18 years) from samples sent to one hospital lab over 1 year with particular focus on management of PHPT.

Methods: A list of patients with an elevated Calcium (>2.70 mmol/L) between August-2008 and July-2009 were obtained from the laboratory database of the local teaching hospital (population served~410,500). Data was collected from pathology (PTH, phosphate, creatinine, calcium trends), radiology, electronic hospital correspondence, and from hospital notes (subset of patients).

Results: 353 patients were identified and in 280 the hypercalcaemia was first documented in the audit period. The breakdown of causes was as follows: PHPT-77(27.5%), malignancy-84(30%), other (Iatrogenic, ESRD, critical illness etc)-44(15.7%), and unknown-75(26.8%) where insufficient investigations/information was available to reach an unequivocal diagnosis. 208 patients, where information was available, underwent detailed study of whom 135(64.9%) were alive and 73(35.1%) deceased at the point of audit. Of the latter 47(64.9%) had underlying malignancy, 7(9.5%)-PHPT, 11(15.1%) - “others”, and 8 (10.9%)-unknown. Further details of patients with PHPT are summarised in Table 1.

Conclusions: This survey/audit has demonstrated a need to improve the further workup of patients with hypercalcaemia. Furthermore, only 62% of subjects with a diagnosis of PHPT were referred to endocrinology. We accept that the findings may in part be attributable to factors such as patient age, co-morbidities, and patient choice and interpretation is also tempered by lack of access to primary care records. However the importance of appropriate endocrinological assessment and management of PHPT may be underestimated by primary care colleagues.

Declaration of interest: There is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported.

Funding: No specific grant from any funding agency in the public, commercial or not-for-profit sector.

Table 1 Details of Primary Hyperparathyroidism Group
Baseline features	Vitamin-D assay	Referral
Male-16 (26.2%)	Done-48 (62.3%)	Endocrine referral-48^@ (62.3%)
Female-61 (73.8%)	Not done-29 (37.7%)	Exceptions-3^* (3.9%)
Alive-70 (90.9%)	Deficiency-15 (11.77%)	Not referred-26 (33.8%)
Deceased-7 (9.1%)	Insufficiency-24 (50%)
	Sub-optimal-19 (39.6%)
	Replete-12 (25%)
Type of PHPT	U/S Renal tract	Vit-D replacement
Symptomatic-20 (27.3%)	Done-35 (38.9%)	Yes-8 (16.7%)
Asymptomatic-36 (46.8%)	Not done-20 (28.6%)	No-12 (29.2%)
Unknown-21 (27.3%)	Exceptions-22^Δ (32.5%)	Level >50nmol/L-18 (23.4%)
		Not measured-29 (37.7%)
Urine calcium:creatinine ratio	Imaging modalities	Management strategy
Done-24 (31.2%)	U/S neck-8 (19.5%)	Medical Rx-27 (35.1%)
Not done- 45 (58.4%)	Sestamibi-6 (14.63%)	Surgical Rx-24 (31.2%)
(including non-referrals)	Combined-15 (36.6%)	Not decided/not known-26 (33.8%)
Exceptions-8^$ (10.4%)	CT neck-2 (4.8%)
^*Two terminally ill, 1 outside area.
^@8/48 seen in other endocrine units.
^ΔThose deemed not suitable for further investigations or not referred to endocrinology, or out of area.
^$Out of area or deemed not suitable for investigations.

Endocrine Abstracts

P54