Paediatric Anaesthesia 1991 1: 53-55

Case report Am I blind? The fear of a 4-year-old boy after total intravenous anaesthesia with propofol

H.-G. SCHAEFER MD, FFARCS AND S.C.U. MARSCH MD

Department of Anaesthesia, University of Basellhntonsspital, Basel, Switzerland

Summa y A transient inability to open the eyes after total intravenous anaesthesia with propofol is described in a 4-year-old child. The possible mechanisms of the production of this complication are discussed.

Keywords: anaesthetics: intravenous, propofol; complications: eye opening

Introduction Propofol has been advocated as an induction and maintenance agent for total intravenous anaesthesia in children. Emergence is smooth, rapid, and clear- headed. The antiemetic and euphoric properties of propofol might be espeady advantageous for young patients.

The inability to open the eyes after total intravenous anaesthesia has already been described (Marsch & Schaefer 1990). For adults this phenomenon is unpleasant and at best bothersome; for a young child this might prove a frightening experience.

Case report A 4-year-old boy, weighing 20 kg, with a history of recurrent upper airway tract infection was scheduled for removal of adenoids and tonsils. The otherwise fit child was premedicated with 7.5 mg rnidazolam and 0.5 mg atropine orally 2 h prior to surgery. Anaesthesia was induced with 25 pg fentanyl,

Correspondence to: Dr H.-G. Schaefer, Department of Anaesthesia, University of BaseKantonsspital, CH-4031 Basel, Switzerland

10 mg of lignocaine and a bolus of 30 mg propofol. Simultaneously, a continuous propofol infusion at 10 mg kg-' h-' was commenced. The trachea was intubated with a 5.0 mm i.d. preformed endotracheal tube after achieving relaxation with atracurium 10 mg. Anaesthesia was maintained with 60% nitrous oxide in oxygen and continuous propofol infusion.

After the end of 40 min of uneventful surgery and recovery from muscle relaxation (TOF ratio > 80%, tetanus 50 Hz > 5 s), the spontaneously breathing child was extubated. As soon as the child regained consciousness he became restless. He denied any pain or sore throat, was well orientated in space and time, but unable to open his eyes (Figure 1).

He was reassured that his eyes might be asleep for another 10 to 15 min, whereupon he settled down. During the following 25 min there was a gradual return to normal eye opening. Eye movements were checked every 5 min by asking the boy to look to the left and to the right. In the beginning there was an ophthalmoplegia with light reactive pupils, followed by a phase of uncoordinated, slow eye movements towards the intended direction before normal control of eye movements was re-established. The mimic

53

54 H.-G. SCHAEFER & S.C.U. MARSCH

Figure 1 The child 5 min after arrival in recovery, sitting in an upright position.

musculature was not impaired and he stuck out his tongue promptly at a time when the eyeballs were still fixed in a central position.

On the first post-operative day he recalled the moments when he thought he had lost his eyesight. He did not remember pain or discomfort after the surgical intervention, although he repeatedly complained of a sore throat the afternoon following surgeiy.

Discussion Propofol has been shown to be safe and effective for the induction of anaesthesia in children with or without premedication (Saint-Maurice ef al. 1989). Its pharmacokinetic profile has been well described and is consistent with using propofol for the maintenance of anaesthesia by continuous infusion (Vander- meersch et at. 1989). The effect on psychomotor performance has been extensively investigated and there is an indication that propofol might have a

specific effect on limbic structures (McDonald et al. 1988). Post-operative euphoria would be especially desirable in paediatic anaesthesia.

The phenomenon we describe might be due to a specific effect of this form of total intravenous anaes- thesia on certain CNS structures which control the oculomotor system. Two recent publications suggest that propofol could interfere with eye opening. Transient impairment of ocular movement has been shown in adult patients (Marsch & Schaefer 1990) and also a prolongation of the time to eye opening on command when compared to other induction agents (Boysen et al. 1989).

Transmission at the neuro-muscular junction is unlikely to be impaired by propofol. We (unpublished results) could not find any decrement of the compound muscle action potentials during repetitive stimulation of both facial and ulnar nerves during propofol infusion before muscle relaxation with atracurium as well as after reversal with neostigmine/glycopyrrolate in adult patients. hg-induced ophthalmoplegia has been described for phenytoin and barbiturates (Esser & Brandt 1983). Diazepam selectively alters saccadic eye movements and methadone also alters smooth pursuit in humans (Rothenberg & Selkoe 1981).

To our knowledge, problems with eye opening after general anaesthesia without propofol have not been reported, though in balanced anaesthesia opiates, benzodiazepines, and barbiturates are used commonly. We suggest two possible explanations for this phenomenon. Firstly, propofol might have interfered with control of eye movements in a similar manner as reported for thiopentone (Eckmiller & Mackeben 1976), with possibly additive effects contributed by midazolam and fentanyl. Secondly, a dissociative emergence, due to rapid clearance of propofol, might allow the establishment of verbal cbmmunication at a time when a patient who has received other forms of anaesthesia is still unrespon- sive to verbal commands. The function of brain stem centres controlling ocular movements might still be impaired when higher cognitive performance has already been regained.

For this child the fear of being blind was very real. Restless children after total intravenous anaesthesia with propofol should be asked to open their eyes. If there are any problems in this regard the child needs to be reassured and the parents informed about this transient and benign phenomenon.

IMPAIRED EYE-OPENING AFTER PROPOFOL 55

References Boysen K., Sanchez R., Krintel J.J., Hansen M., Haar P.M. &

Dyrberg V. (1989) Induction and recovery characteristics of propofol, thiopental and etomidate. Acta Anaesthesiologica Scandinavica 33, 689-692.

Eckmiller R. & Mackeben M. (1976) Functional changes in the oculomotor system of the monkey at various stages of barbiturate anesthesia and alertness. Pflugers Archiv, European journal of Physiology 363, 35-42.

Esser J. & Brandt T. (1983) Pharmakologisch verursachte Augen- bewegungsstorungen-Dfferentialdiagnose und Wirkungs- mechanismen. Fortschritte Der Neurologic-Psychiatre 51, 41-56.

Marsch S.C.U. & Schaefer H.G. (1990) Problems with eye opening after propofol anaesthesia. Anesthesia and Analgesia 70, 127-128.

McDonald N. J., Mannion D., Lee P., OToole D.P., O'Boyle C. & Keane P.K. (1988) Mood elevation and outpatient anaesthesia. Anaesthesia 43 Suppl, 68-69.

Rothenberg S.J. & Selkoe D. (1981) Specific oculomotor deficit after diazepam II. Smooth pursuit eye movements. Psycho-

Saint-Maurice C., Landais A., EstPve C., Mac Gee K. & Girompaire D. (1989) Utilisation du propofol comme agent d'induction en anesthesie pediatrique. A n d e s Francaises DAnesthesie et de Reanimation 37, 39-43.

Vandermeersch E., Van Hemelrijck J., Byttebier G. & Van Aken H. (1989) Pharmacokinetics of propofol during continuous infusion for pediatric anesthesia. Acta AnaesthesioZogica Belgica

p h n ~ a c o l o g y 74,237-240.

40, 161-165.