Portuguese Version

Year:  2001  Vol. 67   Ed. 5 - (10º)

Artigos Originais

Pages: 672 to 675

Efficacy of chloral hydrate sedation in children undergoing transnasal flexible endoscopy

Author(s): José A. Patrocínio 1,
Lucas G. Patrocínio 2,
Pérsio M. Amaral 3,
Alexandre S. F. Aguiar 3,
Tomas G. Patrocínio 4

Keywords: nasal obstruction, chloral hydrate, transnasal flexible endoscopy

Material and method: A hundred consecutive subjects, aged one to four years, without neurological deficits and with complaints of nasal obstruction were examined by transnasal flexible endoscopy (TFE). Study design: Prospective clinical randomized. Aim: The proposal of the present study was to evaluate the efficacy of choral hydrate as a sedative for the conduction of the exams, in the dose of 100 mg/kg PO. We assessed facility of the procedure as a result of the sedation and possible complications. All the 100 patients were sufficiently sedated with the administration of chloral hydrate in the described dose. Conclusion: It allowed conduction of TFE with no need for movement restriction by parents, association of another more powerful drug nor general anesthesia. There were no complications.


Nasal obstruction in children is one of the most frequent complaints in the office of the otorhinolaryngologist. It is somewhat difficult to diagnose the cause of obstruction, however, with the advent of flexible endoscopy, nasofibroscopy or flexible transnasal endoscopy became the preferred test for assessment and diagnosis of upper airway pathologies. This test, compared to paranasal sinuses x-rays, is undoubtedly more sensitive. However, the application of the endoscopic technique in children from one to four years is difficult because they do not cooperate. In such cases, it is required to sedate them - and chloral hydrate seems to be a good option for that purpose. It is one of the most powerful sedatives used in diagnostic procedures of pediatrics4, such as encephalography, computed tomography, magnetic resonance imaging, dental treatment and electrocardiography, among others.

Chloral hydrate is described as colorless crystals of penetrating and ochre odor and caustic and sour taste. Its action is hypnotic and sedative, and it is very effective to induce sleep, but not to prolong it. Sleep is quickly induced and is profound, tranquil and lasts for about one to two hours. Its mechanism of action is unknown. It should not be used as an anesthetic because its safety margin and toxic threshold are too close, nor as an analgesic, because it does not have action over the painful processes.

Restrictions to its use are reserved to cases of patients who use oral anticoagulants and concomitant administration of alcohol because of the maximization of its hypnotic potential. Chloral hydrate is a powerful irritant of skin and mucosas. It causes unpleasant taste, nausea and occasional vomiting and bloating. A 10g dose is considered toxically for oral administration in adults, although there are reports of patients who died after intake of 4g and other who have survived after ingesting more than 30g. The chronic use of chloral hydrate may cause physical dependence, tolerance and addiction14.

Adult doses range from 0.5 to1.0g for a mild hypnotic effect, up to 2.0g. In patients with bulk muscle mass, the calculated dose may be higher, reaching the threshold of toxicity and it should be carefully applied or radically contraindicated. Pediatric doses may be calculated based on weight: 100mg/Kg of body weight for the first 10Kg and 50mg/Kg for each additional kilogram2.

The purpose of the present study was to evaluate efficacy of chloral hydrate as a sedative in children aged one to four years before flexible transnasal endoscopy.


We saw consecutively 113 children aged one to four years, both genders, with no neurological disorders, who had nasal obstruction complaints. In 13 of them we conducted transnasal flexible endoscopy without sedation. The other 100 children comprised the studied population. To perform transnasal flexible endoscopy, we used 4mm-flexible Mashida endoscope, under sedation with PO chloral hydrate, 100mg/Kg of body weight for the first 10 kg and 50mg/Kg for each additional kilogram.

Children came to the exam after three hours of fasting. They were weighted and we calculated the dose of the sedative medication. We explained to parents why the children were taking the drug and the possible effects caused by it: They all consented. A capillary oxymeter was used to control O2 saturation. Forty minutes after intake of chloral hydrate, children were taken to the videoendoscopy room and the test was carried out with the child sitting on the lap of the mother or father, with mild contention of movement. Before inserting the endoscope, we instilled in both nostrils oxymetazoline 0.25% and lidocaine 2%, for vasoconstriction and topical anesthesia. The procedure was then conducted bilaterally and we evaluated all the possible affections of the nasal fossa: inflammations, such as edema and hyperemia of pituitary, degeneration of turbinate; infections, such as presence of secretion, mucosa lesions, and anatomical affections, such as turbinate hypertrophy, nasal septal deviation, degree of choanal obstruction by adenoid hypertrophy, fractures, choanal atresia, neoplasia and foreign bodies. Patients were discharged back home only after waking up. In the end, the responsible person was asked about his/her satisfaction with the procedure.


All the one hundred patients received PO chloral hydrate at the doses previously described, for a level of sufficient sedation. The transnasal flexible endoscopy was carried out with no need for stronger contention by the parents or any other more powerful drug used to sedate patients.

In average; patients took one hour and 50 minutes to wake up, and the maximum was two hours and 16 minutes. All accompanying people reported they were satisfied with the procedure. Moreover, there were no complications.


Chloral hydrate has been successfully used in other specialties. Rumm et al. (1990)15 evaluated the efficacy of chloral hydrate sedation in 50 children submitted to encephalography and they concluded that children with neurological disorders present a higher degree of sedation failure than neurologically normal children. According to the authors, chloral hydrate is a safe and effective oral sedative, except for neurological cases that require an alternative drug. Therefore, in our study, we evaluated only children with no neurological disorders.

Klein8, in 1992, used chloral hydrate as a pre-medication for invasive and painful procedures in cancer children. Most pediatric oncologists believe that pre-medication is necessary in case of children submitted to bone marrow puncture for myelogram and lumbar puncture. They also stated that lack of knowledge about pharmacology and the myths concerning this kind of procedures hinder its use. In view of that, we conducted the present study to show that the drug is safe.

Jaafar et al.7, in 1993, evaluated the effects of PO chloral hydrate as sedatives to measure intraocular pressure in 50 children below 6 years of age, and they did not find any significant side effect and managed to have effective sedation, although some children resisted swallowing the medication because of its sour taste. In the same year, Lipshitz et al.9 submitted 140 children aged 0 to 36 months to echocardiography and evaluated the side effects of chloral hydrate: before sedation (ataxia and sedation), delay in sedation, light sleep during sedation and behavioral modifications after sedation. They concluded that it is a safe and effective drug and suggested that the parents be previously informed about the effects of chloral hydrate. In our case, parents agreed to the use of medication, did not care about children's sleepiness and only asked for how long they would sleep.

Duncan et al.6, in 1994, used a dose of 75 mg/kg of body weight and considered chloral hydrate use a simple sedation technique for dental treatment in pre-school children, with supplementation of oxygen and nitrous oxide.

Napoli et al. (1996)12 demonstrated the safety and efficacy of chloral hydrate in 405 children, aged in average 13 months (three weeks to 14 years), submitted to echocardiography and they obtained a 2% failure rate. It was considered that children below 3 years of age are more easily sedated.

In 1997, Malis et al.11 considered chloral hydrate as the preferred sedative for imaging tests and it was later approved by the American Academy of Pediatrics to monitor cardiopulmonary functions in children below 5 years of age.

The American Academy of Pediatrics advocated the use of chloral hydrate, in specific cases, for facilitation of health processes of children by using procedures that require sedation, provided that cardiopulmonary functions were monitored1.

Liu et al.10, in 1997, analyzed the sedative effect of chloral hydrate and diazepam in 204 children during computed tomography scan and concluded that the effect of both drugs were similar in infants, whereas in pre-school children diazepam had a stronger sedative effect.

Campbell et al.3, in 1998, compared chloral hydrate and intramuscular injections of ketamine, meperidine and promethazine for the sedation of 15 pediatric patients aged 3 to 5 years submitted to dental treatment, and they reached satisfactory sedation within 40 minutes in the group of patients who took chloral hydrate.

Pershad et al.13; in 1999, evaluated the effects of overdose of chloral hydrate, which is manifested as a depressive action on the central nervous system and arrhythmia. Intakes greater than 1.5 to 2.0g produce symptoms in children and adults. Treatment included gastrointestinal irrigation, treatment of arrhythmia and care with mental compromise.

D'Agostino et al. (2000)5 compared the sedative effect of chloral hydrate and midazolam in 40 children aged two months to 8 years submitted to neuroimaging studies. Chloral hydrate was used in 75mg/Kg doses, maximum dose of 2.0 and midazolam at 0.5g/Kg weight, maximum dose of l0mg, both PO. They concluded that in such dosages, chloral hydrate seems to be more effective than midazolam.

In the same year, Wilson et al.17 conducted a retrospective study in 600 children submitted to dental treatment and sedation with chloral hydrate, meperidine, hydroxyzine (anti-histaminic) and midazolam. In the study, the authors associated the drugs in three patterns: chloral hydrate + hydroxyzine, chloral hydrate + meperidine + hydroxyzine and midazolam. They found a significant difference between the associations of the drugs and behaviors and physiological variables. They concluded that the association chloral hydrate + meperidine + hydroxyzine produced significantly more sedation than midazolam alone.

Chloral hydrate has an easy route of administration, extremely brief duration of pharmacological action and quick recovery, with little or no hangover effect, as is the case of barbituric and benzodiazepinic drugs. Before we standardized the present study, there were two cases of excessive sleepiness. We blamed on topical lidocaine, which was sprayed in the nose at 10% concentration at that time. As from the date we started to use it at 2%, no further problems were noticed.

There seem to be no contraindications in this young age range. It should not be used in pre-school children with known heart, liver or kidney diseases and/or in allergic reactions to the drugs used in other circumstances. The side effects of the recommended doses are mild and reversible, and it is a drug that has little effect on breathing and blood pressure. Severe cases are related to chronic and abusive use of the drug. Salmon et al., in 1995, demonstrated that chloral hydrate was potentially carcinogenic and genotoxic, causing in vivo and in vitro chromosome alterations16. The continuous use of high doses, toxic doses or overdose may cause peripheral vasodilation, respiratory depression, hypotension, arrhythmia, heart contractility depression, and shortening of the refractory period, in addition to coma and death. These considerations should not be forgotten, despite the fact that in the present study we evaluated only one to four-year old children who received the drug only once and at the recommended dose, not incurring in the risks listed above.


The present data suggested that chloral hydrate facilitates enormously transnasal flexible endoscopy in pediatric patients aged one to 4 years because of its effective sedation and absence of complications, if used according to the recommended doses.

Finally, it is an effective, safe, cheap and easy to handle and administer drug. The otorhinolaryngologists who are willing to have a quicker, high quality and smoother procedure for themselves, the patient and the parents should make use of this drug.


1. AMERICAN ACADEMY OF PEDIATRICS, COMMITTEE ON DRUGS - Guidelines for monitoring and management of pediatric patients during and after sedation for diagnostic and therapeutic procedures. Pediatrics, 89(6):1110-5, 1992.
2. AMERICAN ACADEMY OF PEDIATRICS, COMMITTEE ON DRUGS AND COMMITTEE ON ENVIRONMENTAL HEALTH. - Use of chloral hydrate for sedation in children. Pediatr, 92(3):471-3, 1993.
3. CAMPBELL, R.L.; ROSS, G.A.; CAMPBELL, J.R.; MOURINO, A.P. Comparison of oral chloral hydrate with intramuscular ketamine, meperidine, and promethazine for pediatric sedation - preliminary report. Anesth. Prog., 45(2):46-50, 1998.
4. COOK, B.A.; BASS, J.W.; NOMIZU, S.; ALEXANDER, M.E. Sedation of children for technical procedures: current standard of practice. Clin. Pediatr. (Phila); 31(3):137-42, 1992.
5. D'AGOSTINO, J.; TERNDRUP, T.E. - Chloral hydrate versus midazolam for sedation'of children for neuroimaging: a randomized clinical trial. Pediatr. Emerg. Care, 16(1):1-4, 2000.
6. DUNCAN, W.K.; DE BALL, S.; PERKINS, T.M. - Chloral hydrate sedation: a simple technique. Compendium, 15(7):884, 886-8, 1994.
7. JAAFAR, M.S.; KAZI, G.A. - Effect of oral chloral hydrate sedation on the intraocular pressure measurement. J. Pediatr. Ophtalmol. Strabismus, 30(6):372-6, 1993.
8. KLEIN, E.R. - Premedicating children for painful invasive procedures. J. Pediatr. Oncol. Nurs., 9(4):170-9, 1992.
9. LIPSHITZ, M.; MARINO, B.L.; SANDERS, S.T. - Chloral hydrate side effects in young children: causes and management. Heart Lung, 22(5):408-14, 1993.
10. LIU, A.Y.; MA, M.L.; FAN, B. - Analysis of sedative effect chloral hydrate and diazepam on children during CT examination. Chung Hua Hu Li Tsa Chih, 32(7):378-9, 1997.
11. MALIS, D J.; BURTON, D.M. - Safe pediatric outpatient sedation: the chloral hydrate debate revisited. Otolaryngol. Head Neck Surg., 116(1):53-7, 1997.
12. NAPOLI, K.L.; INGALL, C.G.; MARTIN, G.R. - Safety and efficacy of chloral hydrate sedation in children undergoing echocardiography. J. Pediatr., 129(2):287-91, 1996.
13. PERSHAD, J.; PALMISANO, P.; NICHOLS, M. - Chloral hydrate: the good and the bad; Pediatr. Emerg. Care, 15(6):432-5, 1999.
14. ROCKVILLE, MD - The United States pharmacopoeia. The national formulary. USP 21st revision (January 1, 1985). NK 16th ed. (January 1, 1985). The United States Pharmacopedial Convention, Inc., 1985.
15. RUM, P.D.; TAKAO, R.T.; FOX, D J.; ATKINSON, S.W. - Efficacy of sedation of children with chloral hydrate. South Med. J., 83(9):1040-3, 1990.
16. SALMON, A.G.; KIZER, K.W.; ZEISE, L.; JACKSON, R j.; SMITH, M.T.- Potential carcinogenicity of chloral hydrate - a review. J. Toxicol. Clin. Toxicol., 33(2):115-21, 1995.
17. WILSON, S.; EASTON, J.; LAMB, K.; ORCHARDSON, R.; CASAMASSIMO, P. - A retrospective study of chloral hydrate, meperidine, hydroxyzine, and midazolam regimens used to sedate children for dental care. Pediatr. Dent., 22(2):107-12, 2000.

1 Faculty Professor and Head of the Service of Otorhinolaryngology, Universidade Federal de Uberlândia.
2 Undergraduate, Medical School at Universidade de Uberlândia.
3 Resident Physician, Service of Otorhinolaryngology, Universidade Federal de Uberlândia.
4 Undergraduate, Medical School at Pontifícia Universidade Católica de Campinas.

Service of Otorhinolaryngology, Hospital Santa Genoveva and Hospital de Clinicas, Universidade Federal de Uberlândia.
Address correspondence to: José Antônio Patrocínio - Rua 15 de Novembro, 327 / Apt° 1600 - Bairro Centro - 38400-214 Uberlândia/ MG.
Tel/Fax: (55 34) 3215-1143-E-mail: lucaspatrocinio@triang.com.br
Article submitted on March 7, 2001. Article accepted on April 26, 2001.





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