Published online before print October 22, 2001, 10.1148/radiol.2213010236
(Radiology. 2001;221:760-762.)
© RSNA, 2001
Pediatric Imaging: Sedation with an Injection Formulation Modified for Rectal Administration1
Mai T. Nguyen, MD,
S. Bruce Greenberg, MD,
Kari R. Fitzhugh, RN and
Charles M. Glasier, MD
1 From the Department of Pediatric Radiology, Arkansas Children’s Hospital, 800 Marshall St, Little Rock, AR 72202. From the 2000 RSNA scientific assembly. Received January 4, 2001; revision requested February 14; revision received June 1; accepted June 7. Address correspondence to S.B.G. (e-mail: greenbergsbruce@uams.edu).
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ABSTRACT
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PURPOSE: To determine if rectal sedation with thiopental sodium produced for intravenous administration provides safe and effective sedation for children undergoing diagnostic imaging.
MATERIALS AND METHODS: Five hundred twenty-five consecutive children (mean age, 2.7 years ± 2.2 [SD]) underwent magnetic resonance imaging (n = 425), computed tomography (n = 89), and nuclear medicine (n = 11) examinations after rectal administration of thiopental sodium injection solution. The solution was prepared from thiopental sodium powder mixed with sterile water to create a concentration of 100 mg/mL. The dose ranged from 25 to 40 mg per kilogram of body weight, with a total dose limit of 1.5 g. The percentages of successful sedations and adverse reactions were evaluated on the basis of data collected at the time of the sedation.
RESULTS: Sedation was successful in 504 (96%) children. Ten (2%) children experienced desaturation, but only three of the 10 experienced sedation failure. All cases of desaturation were treated successfully with head repositioning, administration of supplemental oxygen, or both. No children experienced vomiting, acute rectal irritation, paradoxical hyperactivity, or prolonged sedation.
CONCLUSION: Thiopental sodium sedation for pediatric imaging, with use of a rectal solution prepared from thiopental sodium preparation for intravenous injection, is safe and effective.
Index terms: Computed tomography (CT), in infants and children • Magnetic resonance (MR), in infants and children • Radionuclide imaging
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INTRODUCTION
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The need for sedation in children undergoing radiologic examinations continues to expand with the introduction of longer, more complex studies (1). Magnetic resonance (MR) imaging is the most common indication for pediatric sedation because of the requirement for immobilization in a claustrophobic, noisy environment (2). Helical computed tomographic (CT) technology has reduced but not eliminated the need for sedation of children undergoing CT. Children undergoing nuclear medicine examinations, especially with single photon emission tomography may require sedation. Older children with developmental delay or mental retardation frequently require sedation (3).
The ideal pediatric sedating agent is safe and effective. The sedation should have rapid onset and recovery, have minimal adverse effects, and be reversible (2,4). A number of sedation protocols have been successful. Chloral hydrate administered orally is the drug used most commonly for pediatric sedation. It is most effective in infants and young children but has a relatively slow onset and an unpleasant taste. Side effects of chloral hydrate include nausea and vomiting, ataxia, nightmares, and a hangover effect (5). Pentobarbital sodium administered intravenously is also popular, but intravenous access is required.
For sedation of children undergoing imaging examinations, the safety and effectiveness of thiopental sodium administered rectally has been established previously (4). The sole supplier (Abbott Laboratories, North Chicago, Ill) of the thiopental sodium rectal preparation discontinued marketing of the product in 1996. The combination of safety, efficacy, ease of administration, and strong parental preference over oral and parenteral alternatives led us to formulate our own rectal thiopental sodium solution from an intravenous preparation. The purpose of this study was to determine if rectal sedation with thiopental sodium produced for intravenous use provides safe and effective sedation for children undergoing diagnostic imaging.
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MATERIALS AND METHODS
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The study group consisted of 525 consecutive children (285 male and 240 female infants and children; mean age, 2.7 years ± 2.2 [SD]; age range, 3 months to 14 years) sedated with rectal thiopental sodium solution before diagnostic imaging from January through August 1998. Children younger than 3 months with contraindication to rectal manipulation, such as chemotherapy, allergy to barbiturates, or airway obstruction, were excluded from the study. The imaging studies included MR imaging (425 studies), CT (89 studies), and nuclear medicine examinations (11 studies). Our study received institutional review board approval.
A radiology nurse determined the need for sedation and that no contraindication for rectal thiopental sodium sedation existed. A nurse performed a directed history and physical for each child. Informed consent was obtained from a parent or legal guardian by a pediatric radiologist. Children aged 3 months to 1 year received nothing by mouth for 3 hours prior to sedation, and children older than 1 year received nothing by mouth for 4 hours prior to sedation.
Monitoring for each patient included continuous pulse oximetry. The children were observed by a radiology nurse from the time of administration of the thiopental sodium until the child returned to his or her baseline level of consciousness. Adverse reactions were assessed by the radiology nurse. Desaturation was defined as a decrease in pulse oxygen saturation of 5% or more from baseline and was treated with administration of supplemental blow-by oxygen administered through plastic tubing near the face and adjustment of the head position. The children remained in the radiology department recovery room until they were awake and able to drink liquids.
A 100 mg/mL concentration of thiopental sodium solution was produced by mixing 400 mg of thiopental sodium powder with 3.6 mL of sterile water in a 5-mL syringe. The initial dose was 25 mg per kilogram of body weight. If adequate sedation was not present within 15 minutes or if defecation of part of the initial dose occurred, a second dose of 15 mg/kg was given. The maximum dose for each child was 40 mg/kg for the study. A total dose of 1.5 g was not exceeded. The dose of the thiopental sodium solution in this study is the same as that previously reported with use of the rectal preparation (4).
An 8-F feeding tube catheter was cut 6–8 cm long, the same length as the tube in the discontinued rectal thiopental sodium kit. The feeding tube was attached to a syringe, and 1–2 cm3 of air was aspirated into the syringe before the thiopental sodium dose was drawn up. After the child was placed in a left decubitus position with the knees drawn up, the feeding tube was inserted into the lower half of the rectum. Thiopental sodium was administered into the lower half of the rectum so that absorption was into the hemorrhoidal veins rather than into the mesenteric veins. This prevented inactivation of thiopental sodium in the liver prior to central nervous system exposure. The thiopental sodium solution was administered with air into the rectum. The air helped push all the thiopental sodium through the tubing into the rectum. The feeding tube was withdrawn, and the buttocks were held together for 2–5 minutes to prevent leakage or evacuation.
Sedation failure was defined as the inability to perform or complete the imaging study after sedation. Sedation was considered successful if the imaging study was completed and motion artifacts were minimal or absent. Adverse reactions, such as respiratory distress, vomiting, rectal irritation, paradoxical hyperactivity, or prolonged sedation, were recorded contemporaneously with sedation. The times from administration of the sedative to initiation of imaging and completion of imaging were recorded.
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RESULTS
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The mean time from administration of the first sedative dose to the start of imaging was 16 minutes ± 10. Administration of a second dose of thiopental sodium was required in 108 (21%) children. The mean time from the administration of the first sedative dose to the completion of imaging was 74 minutes ± 54. Successful sedation occurred in 504 (96%) of the 525 children.
Desaturation occurred in 10 patients (1.9%) and was successfully treated with head repositioning, blow-by oxygen administration, or both. No child required intubation or hospitalization. Three patients experienced both sedation failure and oxygen desaturation (0.6%). No episodes of vomiting, rectal irritation (copious or bloody rectal discharge), paradoxical hyperactivity in response to sedation, or prolonged sedation (profound sleepiness longer than 2 hours after rectal sedation) occurred.
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DISCUSSION
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The high success rate of 96% with few adverse reactions with use of the intravenous thiopental sodium solution for rectal sedation is comparable to findings in prior studies with the rectal preparation (4,6,7). The time until the onset of sedation was also comparable to that in prior studies (4,6). Methohexital sodium, an ultrashort-acting barbiturate, has also been used successfully for rectal sedation. Although a 95% success rate for children undergoing CT has been reported for methohexital sodium, respiratory depression occurred in 6% of sedated children (8). Methohexital sodium has a faster onset of sedation but shorter duration, which make it less suitable for use before longer examinations, such as MR imaging. Methohexital sodium can induce seizures in children with temporal lobe epilepsy.
Oral agents are safe and easily administered, but they have prolonged onset and duration of action (2). High-dose oral chloral hydrate is 96% successful in sedating children younger than 4 years before MR imaging (9). However, sedation was successful in only 81% of children older than 4 years (9). Administration of chlorpromazine hydrochloride before chloral hydrate was shown to extend the usefulness of chloral hydrate in older children (10), but this is no longer recommended because of prolonged QT intervals, which may be associated with cardiac arrhythmia (11). Respiratory depression is uncommon with chloral hydrate and occurs in only 4% of children (9).
Intravenous pentobarbital sodium sedation is successful in 96% of children sedated for MR imaging and in 97% of children sedated for CT (12). Pentobarbital sodium is more invasive, requiring intravenous access. Sedation with oral pentobarbital sodium is now being performed in several centers (1). Rage occurs with pentobarbital sodium in 1.2% of children receiving intravenous pentobarbital sodium (1). In our study, paradoxical hyperactivity did not occur in any child receiving thiopental sodium sedation. Rectal sedation is more acceptable to children and parents because it is not painful.
In conclusion, intravenous thiopental sodium administered rectally provides the safe and effective sedation needed for pediatric diagnostic imaging examinations. The ease of administration compared with intravenous administration and the greater reliability of rectal compared with oral sedation make rectal thiopental sodium an attractive alternative to intravenous pentobarbital sodium or oral chloral hydrate.
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FOOTNOTES
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Author contributions: Guarantor of integrity of entire study, S.B.G.; study concepts and design, all authors; literature research, M.T.N.; clinical studies, S.B.G., C.M.G., K.R.F.; data acquisition and analysis/interpretation, all authors; statistical analysis, S.B.G.; manuscript preparation and definition of intellectual content, all authors; manuscript editing, S.B.G., C.M.G.; manuscript revision/review and manuscript final version approval, all authors.
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REFERENCES
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Karian VE, Burrows PE, Zurakowski D, Connor L, Mason KP. Sedation for pediatric radiological procedures: analysis of potential causes of sedation failure and paradoxical reactions. Pediatr Radiol 1999; 29:869-873.
-
O’Brien JF, Falk JL, Carey BE, Malone LC. Rectal thiopental compared with intramuscular meperidine, promethazine, and chlorpromazine for pediatric sedation. Ann Emerg Med 1991; 20:644-647.
-
Keengwe N, Hegde S, Dealove O, Wilson B, Yates RW, Sharples A. Structured sedation programme for magnetic resonance imaging examination in children. Anaesthesia 1999; 54:1069-1072.
-
Glasier CM, Stark JE, Brown R, James CA, Allison JW. Rectal thiopental sodium for sedation of pediatric patients undergoing MR and other imaging studies. AJNR Am J Neuroradiol 1995; 16:111-114.
-
Hobbs WR, Rall TW, Verdoorn TA. Hypnotics and sedatives: ethanol In: Goodman & Gilman’s the pharmacological basis of therapeutics. 9th ed. New York, NY: McGraw-Hill, 1996; 381.
-
Handan ALP, Brahim G, Zerrin O, Cahit K, Huseyin T, Suat E. Efficacy and safety of rectal thiopental: sedation for children undergoing computed tomography and magnetic resonance imaging. Pediatr Int 1999; 41:538-541.
-
Beekman RP, Hoorntje TM, Beek FJA, Kuijten RH. Sedation for children undergoing magnetic resonance imaging: efficacy and safety of rectal thiopental. Eur J Pediatr 1996; 155:820-822.
-
Pomeranz ES, Chudnofsky CR, Deegans TJ, Lozon MM, Mitchiner JC, Weber JE. Rectal methohexital sedation for computed tomography imaging of stable pediatric emergency department patients. Pediatrics 2000; 105:1110-1114.
-
Greenberg SB, Faerber EN, Aspinal CL, Adams RC. High dose chloral hydrate sedation for children undergoing MR imaging. AJR Am J Roentgenol 1993; 161:639-641.
-
Greenberg SB, Faeber EN, Radke JL, Aspinal CL, Adams RC, Mercer-Wilson DD. Sedation of difficult to sedate children undergoing MR imaging: value of thioridazine as an adjunct to chloral hydrate. AJR Am J Roentgenol 1994; 163:165-168.
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Hartigan-Go K, Bateman DN, Nyberg G, Martensson E, Thomas SH. Concentration related pharmacodynamic effects of thioridazine and its metabolites in humans. Clin Pharmacol Ther 1996; 60:543-553.
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Hubbard AM, Markowitz RI, Kimmel B, Kroger M, Bartko MB. Sedation of pediatric patients undergoing CT and MRI. J Comput Assist Tomogr 1992; 16:3-6.
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ABSTRACT
INTRODUCTION
