Methods
This study was a prospective double-blinded parallel randomized clinical
trial conducted at Torabinejad Dental Hospital in School of Dentistry,
Isfahan University of Medical Sciences, Iran. The protocol to this study
was submitted under the code of IRCT20190626044013N2 in the Iranian
Registry of Clinical Trials. This study was registered at Ethics
Committee of Isfahan University of Medical Sciences, Isfahan, Iran under
registration code: IR.MUI.RESEARCH.REC.1399.763 at 3 March 2021.
This trial was conducted in complete accordance with the Declaration of
Helsinki. [8] Power analysis showed that a sample size of 25 in each
group was needed for a significance level set at 0.05 and a power of
80%. The participants (aged 10-50 years) were intellectually disabled
without systemic problems or physical disability, who needed to receive
dental services under general anesthesia. The patients were considered
to have intellectual disability if they had problems in both
intellectual and adaptive functioning in conceptual, social and
practical domains according to American Psychiatric Association. [9]
The exclusion criteria were patients who used anti-depressants,
anti-convulsive, anti-psychotic, anti-hypertensive or tranquilizer
drugs. Patients suffering from hepatic disorders, allergic to soybeans
or eggs and those with a body mass index (BMI) equal to or more than 40
were also excluded. Using the simple sampling method, 50 patients
referring to the dental hospital center were included in the study. An
informed consent was obtained from the patient’s guardian before
enrolment in the study.
Patients were randomly divided into intervention and control groups
using a computer‐generated sequence with an allocation ratio of 1:1. The
patients were blind to their category, and their allocation was
concealed in sequentially numbered, opaque sealed envelopes prior to the
beginning of procedure. Patient enrolment and intervention assignment
was carried out by a person unaware of the content of envelopes. In both
groups, the drug regimen used to induce anesthesia was 5 mg/kg of sodium
thiopental (VUAB Pharm Inc, Roztoky, Czech), 0.8 mg/kg of atracurium
(Caspian Tamin, Rasht, Iran), and 1-2 mcg/kg of fentanyl (Aburaihan
Pharmaceutical, Tehran, Iran), and maintenance was achieved with
propofol (Dangkook Pharm, Choong Cheong Book-Do, Korea) at a rate of 100
mcg/kg/min. After the induction of anesthesia, the
intervention group received additional doses of dexmedetomidine (Exir
Pharmaceutical Co, Borujerd, Iran) by infusion with a rate of 2
mcg/kg/h as an anesthetic adjuvant until the end of
anesthesia. For the control group, equal amounts of 0.9% saline were
administered as placebo.
Patients’ demographic information was recorded before the procedure.
During the anesthesia, the patient’s systolic and diastolic blood
pressures for every 15 minutes, the duration of anesthesia, and the type
and number of dental treatments performed were recorded. If a patient
had pain or restlessness in recovery, the relevant symptoms were
recorded and analgesia was prescribed as per need. The Richmond
Agitation Sedation Scale (RASS) was used to assess patients’ agitation
levels in the recovery. [10] The recovery time for each patient was
recorded before they got discharged. Patients were discharged only after
they scored at least 9 in the Post Anesthesia Discharge Scoring System.
Assessments were done by a person who was blind to the intervention, and
the obtained data were analyzed by independent t-test, repeated measures
analysis of variance (ANOVA), LSD post-hoc and Mann-Whitney tests using
SPSS (Clarivate Analytics) version 23 software.