The Length Of Stay In Patients Undergoing Diagnostic MRI And CT-Scan With Intravenous Anesthesia At Outpatient Clinic Dr. Soetomo General Hospital: An Overview

Received: September, 1, 2020 Revised: February, 10, 2021 Available online: May 2021 Magnetic Resonance Imaging (MRI) and Computerized Tomography (CT) Scans might be challenging for children or individuals with anxiety or claustrophobia. General anesthesia aims to increase the success rate, but inadequate management can result in a longer length of stay. This study aims to analyze patients' length of stay on MRI and CT-scan with intravenous anesthesia. This was a descriptive observational study. The data were collected retrospectively from the medical records at General Diagnostic Center Dr. Soetomo General Hospital. A total of 721 patients underwent MRI or CT Scan procedures with intravenous anesthesia during 2017-2018. The data obtained were patients' age, gender, procedure, physical status, comorbid, type of anesthesia drug, diagnostic procedure duration, length of observation in the Post Anesthesia Care Unit (PACU), and overall length of stay. All MRI procedures used a midazolam-propofol combination. Meanwhile, only one CT scan procedure used those combinations, and other CT scan procedures utilized propofol. Patients undergoing MRI had a length of stay with a mean duration of 6,6,3±1,26 hours, compared to CT scans with 5,20 ±1,38 hours, due to the lengthier procedure and observation duration in the PACU. Patients undergoing MRI have a longer overall length of stay than the ones doing CT scans.


INTRODUCTION
Magnetic Resonance Imaging (MRI) and Computerized Tomography (CT) Scans have been widely used in Indonesia. These diagnostic procedures require patients to stay still for a certain amount of time during the process, which might be hard to achieve for patients with certain conditions, such as children and patients with anxiety or claustrophobia. General anesthesia to increase these diagnostic procedures' success rates has been commonly used (Bailey et al., 2016;Choi et al., 2018;Rubin, 2014).
According to Mujiburrahman, there were 1.399 and 1.048 procedures in 2015 and 2016 in the General Diagnostic Center of Dr. Soetomo General Hospital that used general anesthesia (Mujiburrahman, 2017).
Ambulatory anesthesia can lower-risk nosocomial infection, better cost-effectiveness, and shorter length of stay. It can be done in patients with physical status (PS-ASA) I and II; and all ages except premature infants (Lee, 2017).
Recovery post-anesthesia procedures are crucial. After anesthesia, patients are observed in the Post-Anesthesia Care Unit (PACU) then assessed with Modified Aldrete Score before getting discharged. This criteria evaluates activities, respiration, circulation, consciousness, oxygen saturation, scaled 0,1, and 2.
The patient can be removed from PACU after reaching a score >9 (Lee, 2017;Shetty & Raveendra, 2015 used propofol is less than thiopental. The mean of Modified Aldrete Score in PACU was also higher in patients who used propofol (Makwana et al., 2016).
Sometimes, there is a complication in patients undergoing anesthesia. Largo-Pineda et al. showed that adverse effects in children aged less than 15 years old happened to 12 children in a study of 4.786 subjects.
The most common negative impact was nausea and vomiting that primarily resulted from inadequate postanesthesia treatment (Largo-pineda et al., 2017). Poor complication management can result in a longer length of stay. No study ever mentioned how long a patient should ideally stay in the hospital. Therefore, this study aims to analyze patients' overall length of stay undergoing diagnostic procedures such as MRI and CT-scan with intravenous anesthesia.

METHOD
This study was a descriptive observational study. The data were collected retrospectively from the medical records in the General Diagnostic Center of Dr. Soetomo General Hospital, which consisted of 721 patients who underwent diagnostic procedures such as MRI and CT scan with intravenous anesthesia from 2017 until 2018. The inclusion criteria were patients with no history of difficult anesthesia and no acute or chronic respiratory system infection. Exclusion criteria were not enough fasting period, difficult intravenous access, life-threatening organ dysfunction, and incomplete medical record. The sample was chosen using total sampling. The data obtained were patients' characteristics: age, gender, procedure, physical status classification, comorbid, type of anesthesia drug and its dose, diagnostic procedure duration, length of observation in the Post Anesthesia Care Unit (PACU), and patient's overall length of stay. The data presentation was descriptive.
The study was initiated with a research proposal and accepted by research supervisors. Its proposal was assessed for ethical clearance. After our hospital's ethical committee approved it, we proceeded with data collection through medical records and data proceedings.
Data obtained from patients' medical records were then presented as a

Drugs used in the procedures
All of the MRI procedures used midazolam and propofol combination. Only one CT scan procedure utilized both; most CT scan procedures used propofol only. The propofol dose was 2mg/kg body weight (BW), while midazolam was 0.15/kg BW. The mean dose of midazolam and propofol used in the MRI procedures sequentially were 2,93±2,31 mg and 78±46,24 mg, while the mean dose of propofol used in most of the CT scan procedures was 23,42±15,23 mg.

Duration of procedures, observation in PACU, and overall length of stay
MRIs took longer than CT scans, with a mean duration of 55,96±15,85 minutes compared to CT scan with a mean duration of 10,31±6,71 minutes. Patients who underwent MRI also took a more extended observation period in the PACU, with a mean duration of 173,61±67,52 minutes compared to CT scans with 135,29 ±62,98 minutes mean duration. Therefore, MRI patients had a longer overall length of stay than CT scans with a mean duration sequentially of 6,6,3±1,26 hours and 5,20 ±1,38 hours.

DISCUSSION
The anesthesia drugs used in our outpatient clinic's diagnostic procedures were propofol and a combination of propofol and midazolam. All MRI procedures used propofol and midazolam. Meanwhile, only one CT scan procedure used propofol and midazolam, and the other 279 CT scan procedures used propofol only. The mean dose of propofol used in MRI was higher, which was 58,78±46,24 mg compared to CT scan with a mean dose of 23,42±15,23 mg. It was possible because the mean age of patients undergoing MRI was older than CT scan, which also came with heavier bodyweight.
Ambulatory anesthesia commonly uses propofol because of its rapid onset and recovery. However, it has a narrow therapeutic range, so that respiratory distress is more likely to occur when there is carelessness in use. In this combination, midazolam plays a role as a sedation agent chosen because of its rapid onset and short half-life (Dasgupta et al., 2017). A study in the Netherlands showed that the mean dose of midazolam needed to sedate a child less than six years old was twice as required for an adult (Verhage, Mulder & Willekens, 2003). A similar thing did not happen in this study. Despite the differences of patients' age, all procedures used the same small dose of midazolam, which was 0.15mg Kg BW. Its combination with propofol is beneficial for both drug use since the dose of propofol was also small, 2mg/kg BW, which lowered respiratory distress. A study in Korea reported that midazolam as a combination of propofol could reduce the dose of propofol needed, so the odds of respiratory distress were lower. The research informed that used only propofol showed the risk of respiratory distress of 7%.
In comparison, the ones that used midazolam and propofol combination indicated the risk of respiratory distress of only 2.8% (Kang et al., 2017). Both propofol and midazolam combinations were used in all MRI procedures because the procedure duration took longer than the CT scan.
Diagnostic procedures in patients who needed general anesthesia consist of these phases: risk assessment, history taking, and physical examination; diagnostic procedure; and post-anesthesia observation in the  (Kang et al., 2017). A study also showed that the overall length of stay (the duration from the end of the anesthetic administering to the condition appropriate for discharge) was longer in patients who received intravenous propofol than intravenous midazolam (p = 0.010). The As an impact of the COVID-19 pandemic, we found difficulties in sample collection due to limited access to medical records installation. Therefore, data collection was used manually using the registration book of patients in the Radiology Unit of General Diagnostic Center.

CONCLUSION
Of all the imaging diagnostic procedures using intravenous anesthesia, there is a longer overall length of stay in patients who undergo MRI than patients undergoing CT scans.