DIAGNOSIS OF RICKETS OF PREMATURITY

869 PRESENCE OF LA MEASURED BY COAGULATION TESTS

patients with LA underwent surgery, and 2 had substantial haemorrhage postoperatively. Nevertheless, an earlier operation on 1 of these 2 patients, before which he had been treated with steroids, did not result in haemorrhage. A 42year-old man with a history of an accidental fracture of the right femur in 1978 was operated on and had heavy bleeding requiring the transfusion of 3 litres of fresh blood. Postoperatively he contracted hepatitis B, and a circulating anticoagulant was detected. In 1981 a new bleeding occurred after a tooth extraction, even though 2 units of fresh plasma had been transfused before the extraction. On June 18, 1984, he was admitted to our hospital with a strangulated inguinal hernia. A study of the clotting profile showed 59

the presence of LA (table) with no other associated abnormality. Before surgery he was treated with 1 mg/kg/day ofprednisone. At 21 days LA was almost undetectable (table), and there was no

haemorrhage during operation or postoperatively. The lack of bleeding during surgery with steroid cover suggests the immunoglobulin itself causes bleeding. The difficulty is that laboratory tests do not identify patients with LA who will bleed during an operation. In the absence ofa history of thrombosis and/or abortions, there will be no indication of the danger. Is it better to give immunosuppressive treatment to every patient with LA who is going to undergo surgery, or should postoperative plasma exchange be given as an emergency measure if bleeding occurs? Laboratory tests are needed to indicate which patients with LA will bleed during an operation. For the moment, we think that preoperative prednisone is the most appropriate treatment. J. ORDI M. VILARDEL

J. ORISTRELL

A = Laboratory

Department of

Internal Medicine, Valle Hebron General Hospital,

Barcelona, Spain

Y. MONASTERIO P. FLORES

1. Editorial. Lupus anticoagulant. Lancet 1984; i: 1157-58. 2. Shaulian E, Shoenfeld Y, Berliner S, Shaklao M, Pinkhas J. Surgery in circulating lupus anticoagulant. Int Surg 1981; 66: 157-59.

for

dllldren

spontaneous fractures.

laboratory methods vary considerably and the normal ranges are poorly established for this weight group. If the alkaline phosphatase level is very high, the infant is likely to have radiological changes but, as the figure shows, some infants with very high levels have radiologically normal wrists and some infants with definite radiological changes have surprisingly low enzyme levels. often

N. MCINTOSH Neonatal Unit and Department of St George’s Hospital, London SW170RE

Radiology,

J. E. WILLIAMS A. J. LYON K. A. WHEELER

1. Kovar

patients with

DIAGNOSIS OF RICKETS OF PREMATURITY

SIR,-There is no agreement on the best way to diagnose rickets of some workers use biochemical criterial and some

prematurity;

radiological.2

limit of normal

Comparison of maximum serum alkaline phosphatase (log scale) and radiological grading of rickets. Alkaline phosphatase was measured in the routine chemical pathology laboratory and the radiological grading followed the method of Koo et awl.4 Grade 1;= osteopenia, grade 2=classical rickets, grade 3=rickets with

M. VALDES A. KNOBEL

J. ALIJOTAS

upper

This probably accounts in part for the differing reported incidences. The incidence is inversely related to birthweight and gestation and rickets is more common if there have been neonatal complications.3 Over 3 years (1981-83) we have monitored prospectively the radiological appearance at the wrist in babies whose birthweight was less than 1000 g and who survived for more than 28 days. 47 infants had both X-rays and repeated measurements of serum alkaline phosphatase. The illustration shows the correlation between these two indices. Our feeding policy is to establish enteral expressed breast milk feeding as soon as possible and to give vitamin D 2000 units daily for 7 days. Over the first few days intravenous nutrition is given, supplementing oral breast milk. We accept the diagnosis of rickets for grades 2 and 3radiological changes, which would give a frequency of 54% in infants weighing less than 1000 g at birth. We believe this is a more objective approach than serum alkaline phosphatase measurements because

I, Mayne P, Barltrop D. Plasma alkaline phosphatase activity: A screening test for rickets in preterm neonates. Lancet 1982; i: 308-10. 2. Kulkarni PB, Hall RT, Rhodes PG, et al. Rickets in very low birthweight infants. J Pediatr 1980; 96: 249-52. 3. McIntosh N, Livesey A, Brooke OG. Plasma 25 hydroxyvitamin D and rickets in infants of extremely low birthweight. Arch Dis Child 1982; 57: 848-50. 4. Koo WWI, Gupta JM, Nayanar W, Wilkinson M, Posen S. Skeletal changes in preterm infants. Arch Dis Child 1982; 57: 447-52.

INCIDENCE OF INFANTILE HYPERTROPHIC PYLORIC STENOSIS IN FUNEN COUNTY, DENMARK

SIR,-Your editorial request for data on infantile hypertrophic stenosis (IHPS)1 prompted us to examine the incidence in our area over a long period. Studies from the United Kingdom suggesting an increasing incidence of IHPS include two 7-year studies (1974-80)2,3 and two 10-year studies (1970-79).4,s Only one study includes both medically and surgically treated cases.2 A study from Australia reported no significant variation in incidence during the period 1966-77.6 Earlier reports suggested declining incidences in Northern Ireland and Sweden.7,8

pyloric

The county of Funen can be considered as a geographically welldelineated and demographically representative 9% sample of the whole of Denmark and is especially suitable for incidence studies. Our study covers the years 1950-1983. The population was 395 535 in 1950 and 453 773 in 1983. To avoid loss of patients with IHPS as the result of incorrect diagnostic coding,3we reviewed all