Previous article Table of Contents  Next article

ORIGINAL ARTICLE
Year : 2017  |  Volume : 11  |  Issue : 2  |  Page : 185-189

Efficacy and safety of intravenous thiopental for sedation during magnetic resonance imaging in pediatric patients: A retrospective analysis


1 Department of Radiology, Outpatient Anaesthesia Service, Faculty of Medicine, Ondokuz Mayis University, Samsun, Turkey
2 Department of Biostatistics and Medical Informatics, Ondokuz Mayis University, Samsun, Turkey
3 Department of Anesthesiology and Pain Medicine, Nationwide Children's Hospital, Columbus, Ohio, USA

Correspondence Address:
Joseph Drew Tobias
Department of Anesthesiology and Pain Medicine, Nationwide Children's Hospital, 700 Children's Drive, Columbus, 43205 Ohio
USA
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/1658-354X.203086

Rights and Permissions
Date of Web Publication27-Mar-2017
 

  Abstract 


Introduction: Although the administration of rectal thiopental for sedation during magnetic resonance imaging (MRI) has been well described, there are limited data regarding its intravenous (IV) use in this clinical scenario. The aim of this study was to investigate the efficiency of IV thiopental for sedation during MRI in the pediatric population.
Methods: A retrospective review was conducted over a 12-month period of pediatric patients who received IV thiopental for sedation during MRI. Data collected included the procedure length, the induction dose, the time to sedation, recovery time, total sedation time, and adverse events. The parents were telephoned and questioned regarding any adverse effect after discharge and their satisfaction (yes = satisfied; no = not satisfied) regarding the sedation process.
Results: A total of 300 (American Society of Anesthesiology I–II status) pediatric patients received IV thiopental for sedation during MRI. The average age of the patients was 4.7 ± 3 years. Thiopental was administered as an initial IV bolus dose of 3 mg/kg, followed by additional bolus doses of thiopental (1 mg/kg) as needed to achieve a Ramsay sedation score of 4. The average procedure length was 20.7 ± 11.9 min. The average total dose of thiopental during the procedure was 5.6 ± 0.9 mg/kg. Patients recovered in an average time of 11 ± 5.6 min after a total sedation time of 31.7 ± 14.2 min. None of the patients had oxygen desaturation, adverse effects before or after discharge, and no patient required unplanned hospital admission. All parents were satisfied with the sedation process.
Conclusion: IV thiopental is an effective, safe, and inexpensive medication for the sedation of children undergoing MRI.

Keywords: Magnetic resonance imaging; pediatric anesthesiology; sedation; thiopental


How to cite this article:
Atalay YO, Leman T, Tobias JD. Efficacy and safety of intravenous thiopental for sedation during magnetic resonance imaging in pediatric patients: A retrospective analysis. Saudi J Anaesth 2017;11:185-9

How to cite this URL:
Atalay YO, Leman T, Tobias JD. Efficacy and safety of intravenous thiopental for sedation during magnetic resonance imaging in pediatric patients: A retrospective analysis. Saudi J Anaesth [serial online] 2017 [cited 2022 Jan 25];11:185-9. Available from: https://www.saudija.org/text.asp?2017/11/2/185/203086




  Introduction Top


With its narrow confines and noisy environment, magnetic resonance imaging (MRI) generally necessitates sedation or general anesthesia for children. Sedation is meant not only to control anxiety but also to maintain immobility and ensure optimal image acquisition.[1],[2] In addition to controlling movement, the medication used for sedation must ensure patient safety and allow for rapid recovery and hospital discharge.[1] Given limited access to the sedated child, agents that provide sedation and yet maintain hemodynamic and respiratory stability are preferable.[3] Among the variety of medications that have been used for sedation, the barbiturates have been used safely in various clinical scenarios for many years.[4],[5] With the advent of newer agents such as propofol and dexmedetomidine, the use of barbiturates such as thiopental has decreased. However, it remains a core medication on the World Health Organization's essential drug list.[6]

For sedation during radiologic procedures, thiopental is generally administered through the rectal route.[7],[8],[9],[10],[11],[12],[13] Although the data concerning rectal thiopental demonstrate its efficacy, onset and recovery times may be somewhat prolonged with limited ability to titrate the dose to achieve the desired effect. Although intravenous (IV) thiopental has been commonly used in the operating room for the induction of anesthesia, there is limited knowledge regarding its IV administration for procedural sedation while maintaining spontaneous ventilation.[14],[15] The current study provides data regarding dosing requirements, efficacy, and safety of IV thiopental for sedation during MRI in pediatric-aged patients.


  Methods Top


Ethical approval for this study (Ethical Committee No. KAEK 2016/54) was provided by the Clinical Research Ethical Committee of Ondokuz Mayis University, Samsun, Turkey. Verbal consent was obtained from the parents. This retrospective study included pediatric patients who received IV thiopental for sedation during MRI over a 12-month period. We excluded patients who had received rectal thiopental or other anesthetic agents, those who had incomplete anesthesia records, and those who had premedication with any other sedative medication before the procedure. Data collected from the patients' records included age, gender, weight, procedure length, time in minutes from the initial administration of the sedative to a Ramsay sedation score of 4 (time to sedation), total thiopental dose, time elapsed from the end of the procedure to meeting the discharge criteria (recovery time), time from adequate sedation (Ramsay sedation score of 4) to meeting the discharge criteria (total sedation time), and adverse effects. The parents were telephoned the day following the procedure and questioned regarding adverse effects (nausea/vomiting, drowsiness, confusion, dizziness, headache, or any unanticipated hospital admission) after discharge and their satisfaction (yes/no) concerning the sedation process.

Procedural technique

On the day of the procedure, the patients were held nil per os for 4–6 h before MRI. A peripheral IV cannula was placed in the awake state. Thiopental was administered as an initial bolus dose of 3 mg/kg over 30–60 s, followed by incremental doses of 1 mg/kg at 2 min intervals to achieve the desired level of sedation which was a Ramsay sedation score of 4 (deeply sedated, responds to a nonpainful stimulus).[16] All patients breathed spontaneously without an artificial airway. The patients were monitored with pulse oximetry, capnography from a nasal cannula, and continuous electrocardiogram (heart rate). Respiratory rate, peripheral oxygen saturation, end-tidal carbon dioxide (CO2), and heart rate were recorded at 5-min intervals throughout sedation process.

Statistical analysis

Statistical analyses were performed with SPSS 18.0 (IBM, Armonk, New York, USA) for Windows. Data are presented as the mean ± standard deviation, median (minimum–maximum), and frequency (%). The Shapiro–Wilk test was used to analyze normal distribution assumptions of the quantitative outcomes. Data were analyzed by Mann–Whitney U-test for nonnormal data. To compare two dependent groups, we used the Wilcoxon-signed ranks test for nonnormal data. A P < 0.05 was considered statistically significant.


  Results Top


Over a 12-month period, 300 patients (128 girls and 172 boys) received IV thiopental for sedation for MRI. Sedation was effective in all patients and allowed for completion of the MRI. All of the patients breathed spontaneously through without an artificial airway. There was no apnea or respiratory problems that required airway/ventilation interventions throughout any of the procedures. The most common procedure was a cranial MRI. The distribution of procedures is listed in [Table 1]. The demographics of the study group are listed in [Table 2]. The average age of the patients was 4.7 ± 3 years, and the average weight was 17.6 ± 8.2 kg. A total of 152 patients (50.6%) were American Society of Anesthesiology (ASA) I status and 148 patients (49.4%) were ASA II status. The average length of the procedures was 20.7 ± 11.9 min.
Table 1: Type of magnetic resonance imaging procedures

Click here to view
Table 2: Demographic and sedation data of the patients (n=300)

Click here to view


The median dose of thiopental for the induction of sedation was 5.0 mg/kg. The average total dose of thiopental during the procedure was 5.6 ± 0.9 mg/kg. When comparing the thiopental dose for the procedures lasting 15 min, 16–30 min, 31–45 min, and longer than 45 min, there was a significant increase in the thiopental dose (median, range) as the time increased (5 mg/kg [3.0–6.6], 5.6 mg/kg [3.8–7.5], 6.6 mg/kg [4.8–8.5], and 8.7 mg/kg [7.8–10] mg/kg, respectively, for the four time epochs, P< 0.001). Heart rate at the beginning of the sedation, at the 5th min, and at the 10th min was 101 ± 12.5, 100 ± 12.4, 100 ± 12.2 beats/min, respectively [Table 2].

The recovery time was 11 ± 5.6 min with a total sedation time of 31.7 ± 14.2 min. None of the patients had oxygen desaturation (oxygen saturation <90%), adverse effects, or unanticipated hospital admissions, and all of the parents were satisfied with the sedation process. The demographic characteristics as well as sedation and recovery times are presented in [Table 2].


  Discussion Top


The current retrospective study evaluated the efficacy and safety of IV thiopental for procedural sedation during MRI in the pediatric-aged patient. Results of the present study demonstrate that IV thiopental provided effective and safe sedation in children undergoing MRIs. The use of thiopental for procedural sedation was first reported in 1979 reporting that it produced sedation as effective as the “cardiac cocktail” which included a combination of intramuscular (IM) meperidine (Demerol), promethazine, and chlorpromazine (Thorazine) otherwise known as the DPT.[17] They reported easier administration, more rapid onset, and shorter duration of sedation. Although the authors noted no complications, they suggested careful observation for respiratory depression.[17] The same authors provided additional data in a prospective randomized trial in 72 pediatric patients undergoing computed tomography (CT) imaging.[18] The patients were randomly assigned to receive either the IM cocktail (2.0 mg/kg of meperidine, 1.0 mg/kg of both chlorpromazine and promethazine) or 25–45 mg/kg of rectal thiopental. Sedation was not achieved in 3% of the thiopental group or in 14% of the IM cocktail group. Additional sedatives were required by 8 patients in the thiopental group and by 5 patients in the cocktail group. The mean time for onset of sedation was 8 min with thiopental and 18 min with the cocktail. The mean duration of sedation was 7 h for the cocktail group and 2.75 h for the rectal thiopental group. All scans were acceptable in the rectal thiopental group, but 14% of those in the IM cocktail were not.

Glasier et al. outlined their experience with the use of rectal thiopental for sedation during either CT or myocardial infarct imaging in a cohort of 462 children.[7] The dosing scheme included an initial dose of 25 mg/kg followed by a second dose of 15 mg/kg if the child was awake 20 min later. The average time to sedation was 12.2 min with a recovery time of 71.1 min. Oxygen desaturation occurred in 11% of the patients and was easily treated with the administration of supplemental oxygen and varying the head position. Additional adverse effects included rectal irritation (34%), sleepiness, nausea/vomiting, and ataxia.

However, others have noted no respiratory depression or oxygen desaturation even in patients with congenital heart disease.[8] Beekman et al. noted that they chose the rectal route of administration because thiopental can cause dose-related respiratory depression when administered IV. The time to sedation was 30 min and the recovery time was approximately 90 min.[8] Alp et al. also evaluated the safety and efficiency of rectal thiopental in pediatric sedation for CT and MRI, again choosing the rectal route given the previously mentioned concerns of respiratory depression with IV administration.[10] They noted oxygen desaturation in 10% of the patients. This was immediately corrected by repositioning the patients' head and neck. While the time to sedation was within 15 min in their study, there is no record of the discharge times. Others investigated a low dose rectal-thiopental regimen, using 15–25 mg/kg in a cohort of 90 children requiring sedation for CT imaging.[19] Oxygen desaturation occurred in 1 patient, vomiting in 2 patients, and fecal soiling in 14 patients.

These reports all demonstrate the potential efficacy and safety of rectal thiopental for sedation during radiologic imaging. However, the importance of strict monitoring of respiratory status with pulse oximetry and end-tidal CO2 monitoring is demonstrated by an incidence of oxygen desaturation in up to 10% of the patients. Despite its efficacy, the recovery time may be prolonged up to 2.5–3 h in some reports. Although generally effective, the absorption and pharmacokinetics of rectal medications may be erratic, affected by the level of placement in the rectal vault given the differential venous drainage of the high and low rectal veins and the effects of first-pass hepatic metabolism.[20],[21] In addition, there are barriers (patient, cultural, and traditional) concerning the use of the rectal route, especially for patients older than 6 years of age.[22] There are also different sociocultural norms, attitudes, and preferences between various countries. While it is favored in certain countries, it is unthinkable to others. The acceptability of rectal drug administrations among older children is generally poor, with the IV route being preferable to many older patients.[20]

To date, there remains a paucity of reports regarding the use of IV thiopental for sedation during MRI. IV thiopental in doses similar to what we used in the current study (initial 3 mg/kg bolus dose with rescue doses of 1 mg/kg) compared favorably in efficacy to the sedative effects of a midazolam-ketamine combination in children undergoing MRI.[14] The authors found thiopental to be safe and effective with shorter total sedation and recovery times than the midazolam-ketamine combination. They further recommended thiopental as a safe alternative to a midazolam-ketamine combination for procedural sedation during MRI in children.[14]

In a prospective trial, a combination of propofol and ketamine was compared with thiopental and ketamine in 50 children, ranging in age from 3 to 5 years during MRI.[15] All of the children were premedicated with IV glycopyrrolate (0.01 mg/kg) and midazolam (0.05 mg/kg). Ketamine (1 mg/kg) was administered just before moving to the MR scanner. After positioning, either propofol (PK group) or thiopental (TK group) was administered at a dose of 1 mg/kg. The need to repeat the dose of medication (propofol or thiopental) was higher in the PK group compared to TK group (40% vs. 8%; P 0.0081). The incidence of oxygen desaturation was comparable whereas recovery time was significantly shorter for the PK group.

In recent years, there has been a shift to the use of newer medications such as propofol or dexmedetomidine for sedation during MRI in children. In comparative studies, onset and recovery times are generally slower with dexmedetomidine although its effects on airway function and respiratory parameters are less.[3],[23] However, others have suggested that the failure rate may be unacceptably high when dexmedetomidine is used as the sole agent.[24] Although its efficacy may be increased by the use of higher dosing regimens, the potential for adverse effects may also increase.[23],[24] An additional concern with dexmedetomidine is the cost which is generally significantly higher than propofol or thiopental.

Given the wide spectrum of patients presenting for MR imaging, it is likely that several alternative medications may be useful to provide effective sedation in this unique clinical setting. In our practice, we have found IV thiopental to be effective and safe with a rapid induction time, brief recovery time, and lack of adverse effects. However, given the potential of all sedative medication to affect hemodynamic and respiratory function, appropriate presedation evaluation and monitoring are required for all patients.[25] One limitation of our study is its retrospective nature, and hence, adverse effects may have been missed or not recorded. We do not have real-time parental feedback, but rather information based on a phone call. Furthermore, IV thiopental is not available in some countries. In addition, we do not have blood pressure data as we did not measure blood pressure during the procedure based on our usual clinical practice. We believe that the intermittent inflation of the blood pressure cuff may disturb lightly sedated patients, which may cause the patient to move and disrupt the MRI procedure. Such a practice is not recommended in patients with comorbid cardiovascular diseases. All of the patients in our current cohort were ASA status I or II. As with propofol, the barbiturates, especially in bolus dosing, can have dose-related cardiovascular effects. We these caveats in mind, we believe that IV thiopental provides effective sedation during MRI. It is a cost-effective alternative to other commonly used agents. Prospective, comparative studies with these agents may help to determine the optimal agent for procedural sedation during MRI.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
  References Top

1.
Schulte-Uentrop L, Goepfert MS. Anaesthesia or sedation for MRI in children. Curr Opin Anaesthesiol 2010;23:513-7.  Back to cited text no. 1
    
2.
Heng Vong C, Bajard A, Thiesse P, Bouffet E, Seban H, Marec Bérard P. Deep sedation in pediatric imaging: Efficacy and safety of intravenous chlorpromazine. Pediatr Radiol 2012;42:552-61.  Back to cited text no. 2
    
3.
Koroglu A, Teksan H, Sagir O, Yucel A, Toprak HI, Ersoy OM. A comparison of the sedative, hemodynamic, and respiratory effects of dexmedetomidine and propofol in children undergoing magnetic resonance imaging. Anesth Analg 2006;103:63-7.  Back to cited text no. 3
    
4.
Sternbach LH. The benzodiazepine story. J Psychoactive Drugs 1983;15:15-7.  Back to cited text no. 4
    
5.
Krauss B, Green SM. Sedation and analgesia for procedures in children. N Engl J Med 2000;342:938-45.  Back to cited text no. 5
    
6.
Hansen TG. Sedative medications outside the operating room and the pharmacology of sedatives. Curr Opin Anaesthesiol 2015;28:446-52.  Back to cited text no. 6
    
7.
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;16:111-4.  Back to cited text no. 7
    
8.
Beekman RP, Hoorntje TM, Beek FJ, Kuijten RH. Sedation for children undergoing magnetic resonance imaging: Efficacy and safety of rectal thiopental. Eur J Pediatr 1996;155:820-2.  Back to cited text no. 8
    
9.
Dejonckheere M. Efficacy and safety of rectal thiopental. Eur J Pediatr 1997;156:338.  Back to cited text no. 9
    
10.
Alp H, Güler I, Orbak Z, Karakelleoglu C, Tan H, Eren S. Efficacy and safety of rectal thiopental: Sedation for children undergoing computed tomography and magnetic resonance imaging. Pediatr Int 1999;41:538-41.  Back to cited text no. 10
    
11.
Nguyen MT, Greenberg SB, Fitzhugh KR, Glasier CM. Pediatric imaging: Sedation with an injection formulation modified for rectal administration. Radiology 2001;221:760-2.  Back to cited text no. 11
    
12.
Alp H, Orbak Z, Güler I, Altinkaynak S. Efficacy and safety of rectal thiopental, intramuscular cocktail and rectal midazolam for sedation in children undergoing neuroimaging. Pediatr Int 2002;44:628-34.  Back to cited text no. 12
    
13.
Gómez-Ríos MÁ, Freire-Vila E, Kuczkowski KM, Pensado-CastiÑeiras A. Comparison of sevoflurane administered through a face mask versus rectal thiopental sodium in children undergoing magnetic resonance imaging. J Matern Fetal Neonatal Med 2016:1-5. [Epub ahead of print].  Back to cited text no. 13
    
14.
Selcuk O, Hancı A, Selcuk E, Turk HS, Turk B, Atalan G. Comparison of sedative effects of midazolam-ketamine combination and thiopental in pediatric patients undergoing magnetic resonance imaging. Med Bull Sisli Hosp 2013;3:122-9.  Back to cited text no. 14
    
15.
Kedareshvara K, Dhorigol M, Mane R, Gogate V. Comparison of propofol and thiopentone along with ketamine for paediatric MRI sedation. Int J Res Med Sci 2016;4:381-4.  Back to cited text no. 15
    
16.
Ramsay MA, Savege TM, Simpson BR, Goodwin R. Controlled sedation with alphaxalone-alphadolone. Br Med J 1974;2:656-9.  Back to cited text no. 16
    
17.
White TJ 3rd, Siegle RL, Burckart GJ, Ramey DR. Rectal thiopental for sedation of children for computed tomography. J Comput Assist Tomogr 1979;3:286-8.  Back to cited text no. 17
    
18.
Burckart GJ, White TJ 3rd, Siegle RL, Jabbour JT, Ramey DR. Rectal thiopental versus an intramuscular cocktail for sedating children before computerized tomography. Am J Hosp Pharm 1980;37:222-4.  Back to cited text no. 18
    
19.
Akhlaghpoor S, Shabestari AA, Moghdam MS. Low dose of rectal thiopental sodium for pediatric sedation in spiral computed tomography study. Pediatr Int 2007;49:387-91.  Back to cited text no. 19
    
20.
van Hoogdalem E, de Boer AG, Breimer DD. Pharmacokinetics of rectal drug administration, part I. General considerations and clinical applications of centrally acting drugs. Clin Pharmacokinet 1991;21:11-26.  Back to cited text no. 20
    
21.
de Boer AG, Moolenaar F, de Leede LG, Breimer DD. Rectal drug administration: Clinical pharmacokinetic considerations. Clin Pharmacokinet 1982;7:285-311.  Back to cited text no. 21
    
22.
Jannin V, Lemagnen G, Gueroult P, Larrouture D, Tuleu C. Rectal route in the 21st Century to treat children. Adv Drug Deliv Rev 2014;73:34-49.  Back to cited text no. 22
    
23.
Fang H, Yang L, Wang X, Zhu H. Clinical efficacy of dexmedetomidine versus propofol in children undergoing magnetic resonance imaging: A meta-analysis. Int J Clin Exp Med 2015;8:11881-9.  Back to cited text no. 23
    
24.
Heard CM, Joshi P, Johnson K. Dexmedetomidine for pediatric MRI sedation: A review of a series of cases. Paediatr Anaesth 2007;17:888-92.  Back to cited text no. 24
    
25.
Tobias JD, Leder M. Procedural sedation: A review of sedative agents, monitoring, and management of complications. Saudi J Anaesth 2011;5:395-410.  Back to cited text no. 25
  [Full text]  



 
 
    Tables

  [Table 1], [Table 2]


This article has been cited by
1 Drug Interaction between Dexamethasone and Ketoprofen with Thiopental in Male Dogs: Effect on the Recovery from Anesthesia and Pharmacokinetics Parameters
Mahdieh Raeeszadeh, Mohammad Pouya Ghaffari, Yoshiaki Hikasa
Veterinary Medicine International. 2022; 2022: 1
[Pubmed] | [DOI]
2 Assessment of Saudi Arabian Nurses’ Knowledge and Attitudes Toward Magnetic Resonance Imaging Safety
Ali Alghamdi, Maaidah Alghamdi, Sultan Alamri, Maha Alshehri, Ibtisam Alatawi, Somyah Alzahrani, Mashael Aldarbi, Nora Alali
Journal of Radiology Nursing. 2021; 40(2): 187
[Pubmed] | [DOI]
3 Comparison of the efficacy of ketamine– propofol versus sodium thiopental–fentanyl in sedation: a randomised clinical trial
Maryam Bahreini, Mostafa Talebi Garekani, Mehran Sotoodehnia, Fatemeh Rasooli
Emergency Medicine Journal. 2021; 38(3): 211
[Pubmed] | [DOI]
4 Efficacy and safety of intravenous thiamylal in pediatric procedural sedation for magnetic resonance imaging
Shinji Irie, Katsuki Hirai, Kyoko Kano, Shuichi Yanabe, Masahiro Migita
Brain and Development. 2020; 42(7): 477
[Pubmed] | [DOI]



 

Top
 
Previous article    Next article
 
  Search
 
    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Access Statistics
    Email Alert *
    Add to My List *
* Registration required (free)  

 
  IN THIS Article
   Abstract
  Introduction
  Methods
  Results
  Discussion
   References
   Article Tables

 Article Access Statistics
    Viewed2491    
    Printed32    
    Emailed0    
    PDF Downloaded155    
    Comments [Add]    
    Cited by others 4    

Recommend this journal