Intra-operative parathyroid hormone in secondaryhyperparathyroidism: is it useful?

10 July 2006

Sir,

We read with interest the article ‘Intra-operative parathy-

roid hormone monitoring in secondary hyperpara-

thyroidism: is it useful?’1 One particular issue draws our

attention.

The analysis of intra-operative parathyroid hormone

(PTH) was carried out on the Roche Elecsys 2010 intact

PTH assay. This is a laboratory-based test as opposed to

a ‘bedside’ analyser. The authors correctly state that the

duration of assay is 18 min. However, the specimen must

be also be centrifuged at 3500 rpm for 5–7 min prior to

analysis. This results in a total processing time of 23–

25 min before considering the time taken to transport the

specimen to the laboratory and communicate the results.

The necessary delay of 15 min between removal of the

last parathyroid tissue and sample collection results in

an absolute minimum of 38–40 min before the

intraoperative parathyroid hormone assay result becomes

available.

Our experience of both primary and renal

hyperparathyroid surgery cases has demonstrated that

intraoperative parathyroid hormone assay on the same

laboratory-based analyser is not feasible without a consid-

erable increase in operative time. Analysis of our series

(unpublished) of 10 cases with a sampling time of

10 min post-resection of parathyroid tissue has shown a

mean delay between the end of the procedure and obtain-

ing the result of 29 min (13–43 min).

It would be interesting to know if the authors have

faced similar delays. If so, do they wait for the result

before finishing the procedure or use the results simply as

a postoperative predictor of long-term surgical success.

The solution would be to use a point of care rapid

PTH analyser to give results in 10–15 min.2 However, at

an initial outlay of for the analyser of up to $150,000 and

cost of per patient of between $360 and $7603 this is

not yet an option available to most within the financial

constraints of the NHS.Mace, A.D. & Stearns, M.P.

Department of Otolaryngology,

Royal Free Hospital, Pond Street,

Hampstead, London NW3 2QG, UK,

E-mail: alasdairmace@hotmail.com

References

1 Roshan A., Kamath B., Roberts S. et al. (2006) Intra-operative

parathyroid hormone monitoring in secondary hyperparathyroid-

ism: is it useful? Clin. Otolaryngol. 31, 198–203

2 Sokoll L.J., Wians F.H. & Remaley A.T. (2004) Rapid intraopera-

tive immunoassay of parathyroid hormone and other hormones:

a new paradigm for point-of-care testing. Clin. Chem. Apr 50,

1126–1135

3 Carter A.B. & Howanitz P.J. (2003) Intraoperative testing for

parathyroid hormone: a comprehensive review of the use of the

assay and the relevant literature. Arch. Pathol. Lab. Med. 127,

1424–1442

Response to Mace and Stearns

21 August 2006

Sirs,

Thank you for your interest in our article.1 Unfortunately,

we fail to understand the relevance of the letter. Our

study evaluates the role of intraoperative parathyroid hor-

mone monitoring in secondary hyperparathyroid surgery.

Turnaround time is not an issue in predicting the

validity of this test, although this can have practical

implications.

The Roche Elecsys 2010 intact PTH (parathyroid hor-

mone) assay, we used in our study is a laboratory based

test with a quick turnaround time comparable with bed-

side analysers.2 Although intraoperative parathyroid test-

ing originally became widely practised as a point-of-care

test, in a survey by the College of American Pathologists,

71% of laboratories performed testing in a central labor-

atory, and only 23% in the operating suite.3 An on-site

approach to testing requires a dedicated technologist and

>1 h of set up time for calibration and instrument

checks, and may require acquisition of additional instru-

mentation and operator training. Costs of central laborat-

ory testing have been estimated at $360 versus $760 for

operating room testing.4 Volume of testing remains an

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556� 2006 The Authors

Journal compilation � 2006 Blackwell Publishing Limited, Clinical Otolaryngology, 31, 556–567

important consideration in deciding which test format is

appropriate for hospitals.

Our technique costs £35 per patient, compared with

about £350 per patient for a bedside test, not including

the cost of hardware and a technician in theatre. In the

current NHS climate, it would be hard to justify the

added cost without additional benefit. We would advo-

cate the usage of central laboratory testing of intraopera-

tive PTH.Roshan, A. & England, J.

Hull Royal Infirmary, Hull, UK,

E-mail: amit.roshan@mac.com

References

1 Roshan A., Kamath B., Roberts S. et al. (2006) Intra-operative

parathyroid hormone monitoring in secondary hyperparathyroi-

dism: is it useful? Clin. Otolaryngol. 31, 198–203

2 Hermse D., Franzson L., Hoffman J.P. et al. (2002) Mulitcenter

evaluation of a new immunoassay for intact PTH measurement

on the Elecsys System 2010 and 1010. Clin. Lab. 48, 131–141

3 Hortin G.l. & Carter A.B. (2002) Intraoperative parathyroid hor-

mone testing: survey of testing program characteristics. Arch.

Path. Lab. Med. 126, 1045–1049

4 Wains F.H. Jr, Balko J.A., Hsu R.M. et al. (2000) Intraoperative

vs. central laboratory PTH testing during parathyroidectomy sur-

gery. Lab. Med. 31, 616–621

Christmas survey: how polite are ENT surgeons?

15 June 2006

Sir,

With the combination of the European working time

directive and the cancellation of elective surgical lists

during the festive period, surgical trainees often find

themselves with spare time to complete audit or research

projects. One of the main difficulties in deciding an audit

or research topic is choosing a project that is clinically

relevant and realistically achievable in the time allocated.

After a comprehensive Medline, PubMed and Cochrane

literature search and the appropriate approval from

Santa’s research and ethical committee, we decided to test

the hypothesis that ‘surgeons are less polite compared to

general practitioners’. The aim of this survey was to

compare the ‘politeness’ of general practitioner (GP)

referral letters to the corresponding hospital clinic letter

from different surgical specialities.

Method

We performed a prospective survey of GP referral letters

and the corresponding hospital clinic letters between

November 2005 and December 2005. Keywords defining

‘politeness’ were identified in a small, pilot survey analy-

sing 25 GP and hospital clinic letters. The keywords iden-

tified were: ‘thank you’, ‘please’, ‘grateful’ and any polite

adjective used to describe the patient, e.g. thank you for

referring this ‘delightful’ lady. Each key word scored one

point. If the same word was used again in the same letter,

no further points were awarded.

A cumulative score (‘politeness score’) was calculated

for each letter, e.g. a letter containing the words ‘thank

you’ and ‘grateful’ scored two, whereas ‘thank you’ alone

scored 1. Minimum and maximum politeness scores for a

letter were 0 and 4 respectively. Our survey included

three surgical specialities: otolaryngology, general surgery

and orthopaedics. The grade of the surgeon dictating the

letter was noted. Clinic letters dictated by the authors

were excluded to avoid bias. Results were analysed using

spss version 11. Statistical significance was taken at the

0.05 level.

Results

The mean politeness score per letter for each speciality

was 1 (otolaryngology), 0.96 (general surgery), 0.82

(orthopaedics) and 1.2 (GP). Using parametric data ana-

lysis (anova), there was a statistically significant differ-

ence in these scores (P ¼ 0.013). Post-hoc Scheffe tests

showed the statistically significant difference to be

between the orthopaedic and GP letter politeness scores.

A breakdown of the average politeness score by each

grade of doctor is shown in Table 1. Further analysis

comparing the politeness score between grades of sur-

geons within and between specialities did not show any

statistically significant difference.

Table 1. Mean politeness score for each grade

Grade No. in group Mean politeness score

GP 118 1.2

Consultant 73 0.93

Registrar 37 0.92

Staff Grade 1 1

Senior House Officer 7 1.14

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Correspondence 557

� 2006 The Authors

Journal compilation � 2006 Blackwell Publishing Limited, Clinical Otolaryngology, 31, 556–567