Falling in and out of consciousness: catatonia in a postoperative patient

A 51-year-old Burmese woman with no family orpersonal history of psychiatric disorders was ad-mittedtotheCriticalCareUnit(CCU)followingananteriorresectionformetastatic(lungandhepatic)adenocarcinoma of the sigmoid colon. Postopera-tivelythereweretwoinitialcomplications:first,anepisode of rectal bleeding from the anastomosissite, necessitating a return to theatre for explora-tion only; second, an episode of pulmonaryoedema, during which there were no prolongedperiods of hypoxaemia, and which resolved fol-lowing non-invasive continuous positive airwaypressureventilation.OnreturntoCCU,thepatientshowed no signs of delirium, was oriented intime, place and person, and was communicatingappropriately.Subsequently, eight hours after returning fromtheatre her Glasgow Coma Scale fell from 15 to 6(E1M4V1), with no obvious focal neurologicalabnormality. Blood tests (i.e. full blood profile,liver function tests, urea and electrolytes) andarterial blood gases revealed no cause for thisdeterioration.Accordingly, she was intubated andventilated, and a head CT scan was performedwhich revealed no apparent abnormalities toexplain her deterioration. She regained a full levelof consciousness the next day. Then, however, herlevel of consciousness progressively dropped overseveral hours. On examination, she kept her eye-lids clenched, and it was impossible to assess herpupils, which rolled backwards on manual eyelidretraction. Otherwise, cranial nerve examinationwas entirely normal, including a good gag reflex.Assessment of upper and lower limb neurologywas equally unremarkable with down-goingplantar responses.A Bi-Spectral (BIS) monitor (routinely used tomonitor intra-operative conscious levels) wasemployed to assess EEG activity and level of con-sciousness, as no electroencephalogram could beimmediately arranged. This demonstrated a bi-spectral index of 85–90, which is associated withwakefulness, and not any major intra-cerebralevent or convulsive activity.