Because of anxiety or a lack of cooperation, the results of many routine ophthalmic procedures, such as retinoscopy, ophthalmoscopy, fundus photography, slit-lamp biomicroscopy, and electrophysiology, are often impossible to obtain from infants and young children. Often, these examinations must be conducted under general anesthesia in order to obtain complete results.
Judisch et al,1 examined the effects of 100 mg/kg chloral hydrate, which is higher than the manufacturer's recommended dose of 50 mg/kg, on approximately 300 children and suggested that sedation may be a useful alternative to examination under anesthesia in pediatric ophthalmology. The exact number and age range of the patients studied was not stated. A review of the ophthalmic literature indicates that a more complete investigation of high dose (80-100 mg/kg) chloral hydrate sedation is lacking.2 So, although it was suggested as a pediatric sedative for use in ophthalmology almost three decades ago,3 questions still racist regarding the safety and effectiveness of chloral hydrate.4
Because high-dose chloral hydrate administration has never been carefully documented in the ophthalmic literature, we sought to determine the safety and effectiveness of a high-dose of chloral hydrate for use in pediatric ophthalmology. The clinical results obtained from 302 children between the ages of 1 month and 5 years were reviewed by both the Division of Ophthalmology and the Division of Quality Review of Children's Hospital Los Angeles.
MATERIALS AND METHODS
The chloral hydrate sedation protocol was used for examination of retinoblastoma, electrophysiological exam, and minor surgical procedures such as chalazion removal and suture removal. Since chloral hydrate is not an analgesic, a local injection of lidocaine (Xylocaine) was used prior to chalazion removal. The patient's respiratory rate was monitored for a 15-second period using a stethoscope; radial pulse was monitored for a 15-second period using a wrist watch, every 15 minutes by a nurse until the patient awoke. Pulse oximetry was not used. AU patients received the same monitoring, regardless of age. Since sedation has been reported to result in disinhibition,1 special care was taken to assure that the patient was monitored until fully awake.
The dose of chloral hydrate recommended by the manufacturer (E.R. Squibb & Sons, Inc) is 50 mg/kg. The amount of chloral hydrate in the present protocol was greater than the recommended dose, from 80-100 mg/kg, not to exceed 3 g.1,5 Supplemental administration of chloral hydrate, when required, was one half of the original dose.
Patients were ordered to have nothing to eat or drink for 4 hours prior to administration of the chloral hydrate in order to decrease the likelihood of vomiting and aspiration, as increased intragastric volumes and pressures create an increased risk of regurgitation.6 The chloral hydrate was administered by mouth with a needle-less syringe inserted into the mouth. Care was taken to eject the drug from the syringe slowly enough to ensure that it was swallowed properly and not aspirated by the patient. The drug was not diluted with water or fruit juice.
The patients, 302 between the ages of 1 month and 5 years, were sedated with chloral hydrate for ophthalmic examination using our protocol during the last 6 years. Although the individuals' ages were not recorded, we estimated that approximately 20% of our patients were under 1 year of age. We were able to complete the clinical procedures without resedation in 88% of the patients, the remaining 12% required resedation (36/302).
No complications involving emesis, respiratory depression, changes in vital signs, respiratory distress, behavioral problems, patient injury, or hospital admission were noted in the 302 patients. There was no incidence of excitement or delirium during induction or awakening, as had been previously reported with a 100 mg/kg dose.1
Although chloral hydrate has been used for a number of years as a sedative in pediatric ophthalmology, questions regarding its effectiveness and safety still persist. Chloral hydrate sedation allows for examination of uncooperative children which would otherwise be impossible or would require more involved general anesthesia. This review of 302 patients sedated with high-dose chloral hydrate suggests that an 80 - 100 mg/kg dose is both safe and effective.
Vomiting has been reported to be a common side effect of chloral hydrate sedation.1,79 While chloral hydrate can be gastric in some patients, we have found that limiting the patient's food and fluid intake for 4 hours prior to drug administration, and not diluting the drug with water or fruit juice, were successful in reducing gastric upset. In fact, emesis was not noted in any of our patients. In addition, drug absorption is probably enhanced by an empty stomach.10
As stated before, no complications such as depression in respiratory rate, change in vital signs, respiratory distress, behavioral problems, injury, or hospital admissions were noted in this study. In a previous study by Judisch et al,1 which used a 100 mg/kg dosage, bradypnea developed in one infant who did not become cyanotic or require respiratory support and recovered in less than 3 hours; one baby, less than 1 month old, required head retroflexion for several minutes to maintain a patent airway. Although more severe complications and death have been reported, they were generally the result of ingestion of very high doses of chloral hydrate.411 Complications resulting from therapeutic doses of chloral hydrate are few and mild, and our results add to those of others in suggesting that chloral hydrate is a very safe and effective sedative for use in pediatric patients.
Previous studies suggest that low doses of chloral hydrate result in a greater incidence of insufficient sedation and need for a supplemental dose, than do higher initial doses of the chloral hydrate. Sheskin et al,7 compared the effectiveness of 50 mg/kg (the manufacturer's recommended dose) and 75 mg/kg. Successful sedation was found in 6% and 65% of the patients respectively. However, 40% to 50% N2O was also administered to these patients which makes interpretation of the results unclear. In the present study, resedation was necessary in 12% of the cases using an 80 to 100 mg/kg dose. This is higher than the 1% to 2% of patients who were not successfully sedated by Judisch et al1 with a 100 mg/kg dose. Given the absence of complications with our protocol, however, the rate of 88% successful sedations without the need for resedation, seems acceptable.
In our experience with 80 to 100 mg/kg chloral hydrate, children generally sedate without fussiness and recover from the drug effects peacefully. Use of low dose chloral hydrate however, and subsequent under-sedation, have often been reported to result in agitation and paradoxical excitement.3 In addition, under-sedation results in somnolence during the induction period and arousal and unmanageability when clinical procedures begin. When this behavior persists, clinical procedures must be terminated.3 We recommend that chloral hydrate not be administered to children over 5 years of age due to the higher risk of under-sedation in older, larger children.
It should be noted that the use of high-dose chloral hydrate sedation is not intended to achieve the level of central nervous system depression that is seen in patients receiving low doses of general anesthetics. Chloral hydrate produces a non-specific depression in cerebral function without altering vital signs,2 and does not provide any analgesia.12 Procedures involving extensive or extremely uncomfortable procedures require use of general anesthetics with intensive monitoring in a controlled environment.
This study, as well as previous studies assessing chloral hydrate sedation, have generally been conducted in controlled hospital settings. Our results suggest that chloral hydrate would also be a safe and effective sedative for use in a private office. Although our results indicate that the use of 80 to 100 mg/kg of chloral hydrate is quite safe, we recommend that patients be monitored during sedation and that a physician be present in case of any possible complications. Specific adverse reactions and appropriate emergency responses have been recently reviewed by Jastak and Pallasch.4 However, use of chloral hydrate sedation appears to be a safe and effective sedative for examination or minor ophthalmic procedures in children.
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10. Musselman RJ, McClure DB. In Wright G, ed. Behavior Management in Dentistry for Children. Philadelphia, Pa: WB Saunders; 1975:146-155.
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12. Judisch GF, Bell WE. Chloral hydrate sedation in children. Am J Ophthalmol. 1980;90:877.