Intraocular haemorrhage as a complication of pneumoencephalography.

Abstract

SYNOPSIS The ocular fundi of 20 patients were examined before and after pneumoencephalography. In four of these, fresh venous retinal haemorrhages were seen, and a further patient had developed an exudate. Possible reasons for a rise in retinal venous pressure include bodily inverting the patient, compression of the thorax, the use of positive pressure respiration, and the air injection itself. It may be advisable to take steps to limit the effects of such possible causative factors.In 1973, Simon and colleagues published an account of several cases of intraocular haemorrhage resulting from air myelography carried out under general anaesthesia. They described three cases of symptomatic haemorrhage occurring in an uncontrolled series of 480 gas myelographies, while in a pilot series of 19 patients examined before and after myelography there were five patients with asymptomatic retinal or preretinal haemorrhages. At the time of the original presentation of this work, the authors were criticised for what appeared to be 'faulty' techniques and, indeed, they pointed out in a footnote that, after certain modifications to the procedure, no further haemorrhagic incidents occurred. It was also claimed that such complications were specific to gas myelography and did not occur with, for example, pneumoencephalography.Retinal haemorrhage is not a recognised complication of pneumoencephalography (Milkowski, 1969;Clark et al., 1970;Bergeron and Rumbaugh, 1971), although intracranial haemorrhage, usually subdural, is well documented

Retinal haemorrhage as a complication of gas encephalography and gas myelography. Prospective study using oxgen gas with a discussion of pathogenetic mechanisms.

“…Hoyt and Beeston (1966) and later Simon and colleagues (1973) appear to have been the first to record retinal haemorrhages provoked by pneumoencephalography and pneumomyelography. These haemorrhages were either intra-or preretinal, and were usually asymptomatic (Moseley and Pilling, 1976). However, an affection of the vitreous body with gross visual reduction was reported by Simon et al (1973).…”

“…E. Slagsvold and J. L. Larsen tribute to such bleedings, especially those causing raised intracranial or intraocular venous pressure or both, possibly as a result of special examination procedures. The technique of having the patient's legs higher than the head results in a stasis of cephalic venous vessels (Simon et al, 1973, Moseley andPilling, 1976). This Trendelenburgh position is particularly unfavourable if longlasting.…”

“…This Trendelenburgh position is particularly unfavourable if longlasting. The somersault manoeuvre to fill the temporal horns with gas is another way of causing increased venous pressure (Moseley and Pilling, 1976) due to compression of the thorax and abdomen by the necessary support (Pearce, 1957). This mechanism is further illustrated by the haemorrhagic retinopathy caused by the Valsalva manoeuvre (Duane, 1973) and by the retinal angiopathy after heavy compression trauma to the chest, in Purtscher's disease (1910).…”

“…Simon et al (1973) observed intraocular haemorrhage resulting from pneumomyelography. Moseley and Pilling (1976) reported retinal haemorrhage after pneumoencephalography in 20% of their patients. These reports stimulated us to examine the retinal fundus in patients submitted to oxygen encephalography (OEG) and oxygen myelography (OMG).…”

Effects of general anaesthesia on size of cerebrospinal fluid spaces during and after pneumoencephalography.

“…Subdural haematomas have been reported complicating pneumoencephalography (see Moseley and Pilling (1976) for bibliography), which may suggest that such a shrinkage occurs, although they could also be related to shrinkage of the cerebrum. If the tendency to ventricular collapse were not resisted-by diffusion of gas into the ventricles during the procedure, for examplethis could cause a reduction in ventricular size, but there is no reason why it should be temporary.…”