The authors describe the case of an infant of 41 weeks corrected gestational age who suffered cardiopulmonary arrest after the administration of Cyclomydril eyedrops (cyclopentolate hydrochloride 0.2%, phenylephrine hydrochloride 1%; Alcon Laboratories) during an outpatient retinopathy of prematurity (ROP) examination.
Cyclopentolate is an anticholinergic that blocks pupillary constriction and ciliary muscle contraction and also inhibits the sphincter pupillae muscle, resulting in mydriasis and cycloplegia. Phenylephrine is an alpha-adrenergic agent that acts directly on the pupillary dilator fibers causing mydriasis but not cycloplegia and is often used in addition to cyclopentolate to achieve greater mydriasis.
They caution that eyedrops used for mydriasis and cycloplegia can be systemicall absorbed, causing serious side effects, including oxygen desaturation, apnea, bradycardia, transient hypertension, delayed gastric emptying and transient paralytic ileus. These effects can be more serious in infants because of their lower body mass and immature cardiovascular and nervous systems.
The patient was a twin female born at 27 weeks’ gestational age weighing 1010 g who presented for a follow-up ROP screening exam 10 days after being discharged from the hospital. Her medical history was significant for patent ductus arteriosus ligation, atrial septal defect and chronic lung disease.
She had previously received Cyclomydril drops as part of routine ROP examinations beginning at 30 weeks’ corrected gestational age and every two weeks thereafter while hospitalized. At each of these examinations, she had received three sets (1 drop per eye) of Cyclomydril each at 5- to 10-minute intervals, without complications.
At her outpatient office examination, her pupils were dilated with Cyclomydril eyedrops, with three sets administered as before. Approximately 15 minutes after the third set of drops were given, she was found to be unresponsive, apneic, cyanotic and pulseless. Cardiopulmonary resuscitation was administered and she was revived after two to three minutes. She was taken to the emergency room and almost three hours after the first set of eyedrops were administered, she experienced another episode of apnea and bradycardia, which resolved with stimulation. During her hospitalization, she was discovered to have new-onset pulmonary hypertension, thought to be related to the recent patent ductus arteriosus ligation.
Subsequent dilated ROP examinations using tropicamide 1% and phenylephrine 2.5% were eventless, even though tropicamide has a similar side effect profile as cyclopentolate.
The authors believe that Cyclomydril contributed to the patient’s cardiopulmonary arrest and that cyclopentolate was the likely culprit.