Lin Liu¹,², Joel Moyo3, Blessed Kondowe4, Patrick Manda4, Jingping Zhang4,5, Junyi Ren3,*6
1.Department of Anesthesiology, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
2.Department of Anesthesiology, Kamuzu Central Hospital, Lilongwe, Malawi
3.Department of Anesthesiology, Mzuzu Central Hospital, Mzuzu, Malawi
4.Department of Radiology, Mzuzu Central Hospital, Mzuzu, Malawi
5.Department of Medical Imaging, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
6.Department of Anesthesiology, Baoji Central Hospital, Baoji, China
*Corresponding Author: Junyi Ren; Email: 76427340@qq.com
Abstract
Background
Magnetic resonance imaging (MRI) in children requires adequate sedation to ensure procedural success. In resource-limited settings, sedative options are often restricted, and comparative data on ketamine and diazepam are scarce. This study aimed to evaluate the efficacy, safety, and MRI completion rates of ketamine versus diazepam for pediatric sedation at a low-resource hospital in northern Malawi.
Methods
We conducted a single-center, retrospective study including children aged 0–14 years who underwent MRI with ketamine (n = 20) or diazepam (n = 36) at Mzuzu Central Hospital between August 2025 and March 2026. Sedation success was defined as Ramsay Sedation Score 4-5 with stable vital signs and absence of movement during MRI. Primary outcomes were sedation onset time, sedation success rate, recovery time, adverse events, and MRI completion rates.
Results
Baseline characteristics were similar between groups. Ketamine was associated with a shorter sedation onset (mean 1.55±0.39 min vs 3.43±0.45 min, P < 0.01), higher sedation success rate(19 (95%)vs 24 (67%), P < 0.05), and longer recovery time (mean 58.64±7.14 min vs 43.10±5.04 min, P < 0.01) compared with diazepam. The incidence of adverse events was similar between the two groups, with no severe complications observed. First-pass MRI completion (19 (95%)vs 21 (58%), P < 0.01) and overall scan success rates (20(100%)vs 25(69%), P < 0.05) were higher in the ketamine group.
Conclusions
In this low-resource setting, ketamine provided faster, more reliable pediatric MRI sedation than diazepam, with higher procedural success and a favorable safety profile. Ketamine may be considered the preferred sedative for pediatric MRI in similar resource-limited hospitals, provided continuous monitoring and anesthetic oversight.
Keywords: pediatric sedation; MRI; ketamine; diazepam; resource-limited settings; Malawi