ERCP is a lengthy and complex therapeutic procedure, requiring high-grade patient collaboration. Sedation and analgesia provide better tolerance and compliance to patients undergoing ERCP by reducing pain, discomfort and stress (1,13,14).
For procedural success, the anaesthetic technique should alleviate pain, anxiety and stress that may cause cardiorespiratory and haemodynamic instability, as well as allow spontaneous breathing of the patient without an airway device (15).
Propofol, a lipophilic drug, has rapid dispersion and elimination times, with no cumulative effect after infusion. Propofol has been evaluated in various regimens for ERCP and has been noted to provide superior sedation quality and shorter recovery time (14). It has been frequently used as a sedative agent for endoscopic procedures over the last two decades. However, propofol can cause deep sedation, as well as dangerous side effects necessitating cardiopulmonary support (2).
In our study, propofol was combined with other medications to reduce its dose and provide optimum sedation without compromising the recovery profile. Dexmedetomidine and ketamine were included in our study owing to their positive recovery profile characteristics, as well as safe anaesthetic effects. In both study groups, propofol was used as a fixed bolus dose, followed by a variable interval bolus.
Dexmedetomidine is a selective alpha-2 agonist with sedative and analgesic properties that does not cause respiratory depression. However, when used as the only sedative agent for endoscopic procedures, it was observed to be ineffective compared with previous studies, because of being neither a complete anaesthetic nor a complete analgesic (11). Therefore, we used it together with propofol. Ghodki PS et al. (16) observed a 62.5% reduction in the induction dose of propofol when co-administered with dexmedetomidine. It was observed that propofol consumption was significantly lower in the 1:4 ketamine-propofol (Ketofol) group compared with the fentanyl-propofol group in patients with obesity undergoing ERCP (2).
In a similar study, Mai W., Abdalla et al. (17) noted that total propofol consumption at the end of the procedure was low but not statistically significant in the dexmedetomidine-propofol group.
The total amount of propofol consumed was the primary endpoint of our study. Although the total dose of propofol consumed in the ketamine group was higher than the dexmedetomidine group, it was not statistically significant.
Ramkiran S. et al. (6) determined the discharge time from the recovery room to be 10±4.17 min in the ketamine group because of the use of low-dose ketamine. Studies using ketamine anaesthesia for interventional cardiology procedures have reported a longer recovery time and haemodynamic instability in paediatric patients (18,19). A study that compared dexmedetomidine-ketamine with propofol-ketamine reported no haemodynamic or respiratory side effects, but a longer recovery time with the dexmedetomidine-ketamine combination (20). Another study that compared the ketamine group with the propofol group observed more frequent agitation during recovery and a longer time for recovery of the baseline mental state (21).
Mai W. Abdalla et al. (17) noted a shorter recovery time after ERCP with the dexmedetomidine-propofol combination compared with the ketamine-propofol combination.
The present study revealed that recovery time was significantly shorter in patients of group DP than of group KP. Nevertheless, no incidence of respiratory depression, need for respiratory support or loss of respiratory reflexes were observed in patients of both groups.
Another study that compared the effects of propofol and dexmedetomidine on cerebral oxygenation determined a statistically significant decrease in cerebral oxygenation between 5 and 10 min of the procedure. However, the authors concluded that this decrease was not clinically significant but could be harmful in clinically unstable patients (22). During the procedure, the HR and MAP values in the dexmedetomidine-propofol group were lower, which may be related to the effect of dexmedetomidine, which is a highly selective alpha-2 agonist. Notably, the average arterial pressure increases in the ketamine-propofol group because of increased diastolic pressure owing to the increased systemic vascular resistance (17).
Bajwa SJS et al. (23) compared the following drug combinations for total intravenous anaesthesia: propofol-ketamine (group I) and propofol-fentanyl (group II). The intraoperative HR and MAP values of group I were increased, whereas they were decreased after induction and intubation in group II, with a statistically significant intergroup difference noted. These results were concordant with the results of the ketamine-propofol group of our study.
Upon intergroup comparison of the haemodynamic profiles of patients, the dexmedetomidine group had a clinically insignificant, but statistically significant slow HR and low MAP compared with the other group. It was observed that the HR and MAP returned to baseline after the termination of anaesthesia.
Compared with group KP, a generally higher HR reduction was observed in group DP, as well as a transient decrease in SBP, DBP and MAP. Even though these findings were significantly different, no intervention was required. Both treatment strategies were determined to be adequate without a significant difference regarding the need for additional sedation.
Demiraran Y et al. (24) studied midazolam against dexmedetomidine for sedation during an upper endoscopy. In the midazolam group, one patient developed apnoea and two patients had desaturation (SPO2 <90%), whereas the dexmedetomidine group had no deterioration in respiratory parameters (respiratory rate, desaturation). On the other hand, Bajwa SJR et al. (23) and Aydogan H et al. (25) reported no cases of respiratory failure in the ketamine-propofol group during upper GI endoscopy. A study by Hasanein and El-Sayed (26) reported agitation and irritability in 2% of patients receiving the ketamine-propofol combination, and the other group that received propofol-fentanyl did not have postoperative cognitive dysfunction.
In our study, two patients in the dexmedetomidine group desaturated, but saturation did not fall below 92%, and no hypoxia developed. Moreover, no hypoxia developed in the ketamine group either. Postoperative cognitive dysfunction was not observed in either study group. This difference could be because of the different types of patients with hyperbilirubinemia, increased liver enzymes and hepatic insufficiency, which may alter the pharmacokinetics and pharmacodynamic effects of ketamine.
The literature review did not reveal any cost calculation related to dexmedetomidine in non-operating room applications. Moreover, studies conducted on patients in intensive care revealed varying results.
Nevertheless, dexmedetomidine may be more cost-effective than other sedative agents in intensive care units (ICUs). Sedation with dexmedetomidine reduced ICU costs when compared with standard care. It was stated that cost savings were achieved by reducing the total ICU stay without prolonging hospital stay after intensive care (27). In another study, dexmedetomidine use was associated with increased total hospital cost, ICU stay and length of hospital stay compared with the use of propofol for sedation in critically ill patients.
In our study, compared with the ketamine group, the dexmedetomidine group exhibited a shorter recovery time but a higher cost.
Nonetheless, the present study had some potential limitations, such as small sample size. Therefore, more studies with larger samples are needed to test the efficacy and safety of the study drugs.
Another limitation was the inability to assess the depth of intraoperative anaesthesia and the incidence of intraoperative awareness because the BIS monitor could not be used. However, we believe that only a small intergroup difference could have existed related to the depth of anaesthesia during the study because of the homogeneity of patients and the similarity of the intervention performed.
In conclusion, dexmedetomidine-propofol and ketamine-propofol combinations are safe anaesthetic combinations that provide haemodynamic stability and low complication rates during the ERCP procedure. The combination of dexmedetomidine-propofol was superior to ketamine-propofol with short recovery time and low propofol consumption, albeit with a higher cost. Nevertheless, future randomised trials are required to confirm these findings.