Arch Dis Child: first published as 10.1136/adc.55.1.84-a on 1 January 1980. Downloaded from

84 Correspondence Methods for improving the prognosis pneumothorax or pneumomediastinum, or both, of 8 %, while bronchopulmonary dysplasia was found in only of mechanically ventilated infants 8% of the survivors. The difference in mortality and with RDS bronchopulmonary dysplasia figures in the two study periods was significant (P<0.05). The infants were similar in respect of birthweights, gestational ages, and severity Sir, of respiratory disease Manginello et al. (Archives, 1978, 53, 878) stated that in We believe that the main advantages of ventilating the ventilatory treatment of infants with severe RDS patients with severe RDS with a volume-cycled venti- the pressure-limited method of ventilation was better lator using the assisted (triggered) method are that the than that of volume-cycled, as with the former, the baby does not have to struggle against the ventilator, FIo, could be reduced more rapidly and complications the respiratory rate is automatically regulated, the respi- or death were less common. We obtained similar improve- ratory centres are continuously activated during the whole ments using volume-cycled ventilation but with a ventilation time, and finally, it is quicker and easier to different approach.1 wean the baby from the ventilator. We studied 56 newborn infants who were given We suggest that before a final conclusion is made on mechanical ventilation for severe RDS between 1973 the superiority of pressure-limited mechanical ventilation and 1976. Only the most severely affected infants were in RDS, controlled trials should be done to compare intubated and given mechanical ventilation. About half pressure-limited ventilation with other methods of of these babies were apnoeic on admission; the others volume-limited ventilation (including the use of PEEP in were ventilated because of progressive and severe assisted ventilation with trigger). deterioration of their clinical status or because of their blood-gases. Arterial pH, Po2, and Pco2 were the only References indications for mechanical ventilation in babies with Marzetti G, Marangoni A, Colarizi P, et al. Riduzione severe hypercarbia, acidaemia, or in those in whom severe della mortalitA e degli esiti polmonari dopo introduzione hypoxaemia persisted despite adjustment of continuous di PEEP in respirazione assistita in neonati > 1200 g con distending pressure and F1o2. sindrome respiratoria ventilati meccanicamente. Abstract During the years 1973-74 we gave mechanical venti- of paper given at the 39th Congress of the Italian Paedi- lation to 31 infants with severe RDS and respiratory atric Society, Venice, 16-19 October, 1978. insufficiency using avolume-cycled ventilator (Bourns LA 2 Llewellyn M A, Swyer P R. Assisted and controlled 104-150) in the controlled mode, with tidal volume of ventilation in the newborn period: effect on oxygenation. 5 ml/kg, respiratory rate of 60-80 min, positive end Br J Anaesth 1971; 43: 926-31. expiratory pressure (PEEP) of 3-7 cmH2O and I: E G MARZETI, R AGosrNo, AND C MoRETrI ratio of 1: 1-1: 2. Mortality was 74 %, pneumothorax Newborn Intensive Care Unit, or pneumomediastinum, or both, occurred in 23 % of Institute ofPaediatrics,

cases, and bronchopulmonary dysplasia was present in http://adc.bmj.com/ 67% of survivors. University ofRome, In our attempts to improve the prognosis for Rome, Italy mechanically ventilated infants with RDS we noted that, during the acute phase of the disease, if we changed from the controlled to the assisted mode (in which the venti- Acute infantile thrombocytosis and lator cycle is triggered by the patient's inspiratory effort) vitamin K deficiency associated with there was often a significant rise ofPao2. This phenomenon had already been described in infants with RDS venti- intracranial haemorrhage lated mechanicallywithout PEEP.2Nevertheless Llewellyn on October 2, 2021 by guest. Protected copyright. and Swyer did not correlate the better oxygenation Sir, obtained with this method with changes in the prognosis The paper by Lorber et al. (Archives, 1979, 54, 471) was in their patients. At the beginning of 1975, after we had especially interesting to me because of my obser- made this observation, infants were set on a Bourns vation of thrombocytosis in a 2-month-old infant (to be ventilator (ventilator setting the same as during 1973-74) reported) in whom pronounced vitamin E and vitamin D with 100% oxygen in controlled respiration as long as and probable vitamin K and vitamin A deficiency arterial pH was <7-30 and Pao2<50-60 mmHg (6.6- (slightly prolonged prothrombin, partial thrombo- 7-9 kPa), and we changed to the assisted mode as soon plastin time, and very low carotene level) were shown. as pH and Pao, attained better values and the patient's Because other causes of thrombocytosis of infancy were respiratory activity was sustained. The patient no longer ruled out, infantile hyperostosis was sought and was had to struggle against the ventilator, there was improved proved by x-ray. oxygenation, and the infant was able to regulate the Since thrombocytosis in infancy has been reported in respiratory rate according to his own needs. With this patients with Caffey's disease,12 possibly related to approach it was possible to lower the FIO2 and to extu- vitamin E deficiency,3 we suggest that at least a hydrogen bate the patient more rapidly. During 1975-76 we venti- peroxide haemolysis test (which was also positive in our lated 25 neonates with severe RDS in this way, with a case) should be carried out in all patients with infantile fall in mortality rate to 48% and with an incidence of thrombocytosis in whom the aetiology is unknown. Arch Dis Child: first published as 10.1136/adc.55.1.84-a on 1 January 1980. Downloaded from

Correspondence 85 Because of intracranial bleeding the head x-ray should were not noted. Also our patient was a term baby of be available to help in the diagnosis of Caffey's disease. 2*86 kg, whereas those described with vitamin E defi- Probable vitamin K deficiency suggests that the level of ciency associated thrombocytosis have been premature other lipid soluble vitamin levels should also be deter- with birthweights of 1 * 5 kg or less.3 None the less, we did mined. not measure tocopherol levels or perform a peroxide SINASI OZSOYLU haemolysis test and so cannot be absolutely certain Institute of Child Health, about this point. Hacettepe University, We agree that these two conditions should be con- Ankara 11191, sidered when thrombocytosis occurs in infancy but are Turkey tempted to observe that their discovery would make the genesis of a high platelet count no less puzzling. Dr Lilleyman comments: References We were interested in Professor Ozsoylu's observations Lorber J, Lilleyman J S, Peile E B. Acute infantile concerning our patient with intracranial bleeding and thrombocytosis and vitamin K deficiency associated thrombocytosis1 and confess that at the time we did not with intracranial haemorrhage. Arch Dis Child 1979; consider the possibility of infantile hyperostosis or vitamin 54: 471-2. E deficiency being present, although we acknowledge 2 Pickering D, Cuddigan B. Infantile cortical hyperostosis that both conditions have been found in patients in whom associated with thrombocythaemia. Lancet 1969; 2: the platelet count is high.2-3 464-5. Against the diagnosis of Caffey's disease in our patient 3 Ritchie J H, Fish M B, McMasters V, Grossman M. was the absence of fever and the fact that there were no Edema and hemolytic anemia in premature infants. A characteristic mandibular or clavicular swellings; as there vitamin E deficiency syndrome. N Engl J Med 1968; were no clinical stigmata of the disorder no x-rays were 279: 1185-90. obtained. J S LILLEYMAN As faras vitamin E deficiency is concerned, we can only Department ofHaematology, say that the reticulocyte count was not recorded above Children's Hospital, 3 % at any time, and the characteristic irregularly con- Western Bank, tracted erythrocytes of the associated haemolytic anaemia Sheffleld SJO 2TH http://adc.bmj.com/ on October 2, 2021 by guest. Protected copyright.