Dexmedetomidine-ketamine combination is a safe alternative for sedation during the cardiac catheterization procedure without the incidence of any hemodynamic or respiratory effects. However, it is associated with some delayed recovery.  

Management of children with congenital heart disease is challenging for anesthesiologists, especially during cardiac catheterization. General anesthesia use with positive pressure ventilation can differ the intracardiac pressures as well as shunt fraction. A deep sedation with pain-free and spontaneously breathing patient on room air is preferred by the cardiac interventionist. Thus, treatment of pediatric patients scheduled to undergo cardiac catheterization by an ideal anesthetic technique should exhibit some integral properties including safety, easy administration, adequate sedation, amnesia, immobility, cardiovascular stability, and fast recovery without residual complications.

A wide range of anesthetic agents such as propofol, ketamine, and dexmedetomidine are recommended for sedation in pediatric patients during cardiac catheterization. The primary goal of anesthesia for catheterization is to induce sedation, anxiolysis, amnesia for the patient, and easy separation from parents with proper maintenance of airway, ventilation, acid-base balance, and temperature. In addition, the anesthetic agent should ameliorate hemodynamic status before, during, and after the procedure tailored to the specific physiology of the individual patient and ensure smooth recovery.

The commonly performed cardiac catheterization laboratory procedures include diagnostic catheterization and interventions such as pulmonary artery angioplasty, aortic-coarctation angioplasty, patent ductus arteriosus occlusion or stenting, ventricular septal defect closure, atrial septostomy, atrial septal defect closure, and aortic/pulmonary/mitral valve dilation.

Rationale behind the research:

The ideal anaesthetic technique for management of pediatric patients scheduled to undergo cardiac catheterization is still not standardized. Therefore, this study was conducted to evaluate comparative effects of dexmedetomidine-ketamine (DK) and propofol ketamine (PK) to obtain an ideal anesthetic agent for purpose of sedation in pediatric patients

Objective:

The objective of this study was to compare the effects of dexmedetomidine-ketamine (DK) and propofol ketamine (PK) combinations on hemodynamic parameters and recovery time in pediatric patients undergoing minor cardiac procedures in cardiac catheterization laboratory.

Study outcome measures:

• Base line characteristics: Age, weight and duration of the surgery
• Main outcome measures: Evaluation of recovery time and assessment of heart rate, mean blood pressure (BP), oxygen saturation (SpO2), respiratory rate every 5 minutes during procedure and heart rate and SpO₂ every 10 min postoperatively

Time points: Baseline and every 5 minutes up to 60 minutes

Study Outcomes:

Baseline: There were no significant baseline differences between the groups.

Outcomes:

• Heart rate was significantly lower in DK group at 5, 10, 15, 20, 25 min post induction in comparison to PK group
• There was no significant difference between mean BP, mean SpO₂ and respiratory rate in group DK and group PK from baseline to 60^th min
• Recovery was significantly delayed in DK group (40.88±8.19) versus 22.28±3.63 min in PK group (p≤0.05)
• Actual ketamine consumption was (2.02 mg/kg/h) in DK group, whereas in PK group, it was (1.25 mg/kg/h). Ketamine boluses consumption was significantly higher in DK group (09 patients in DK vs. 02 patients in PK) (p≤0.05)

Cardiac catheterization procedures are different in children and adults in a variety of ways including diifferences in disease patterns,  requirements for the procedure, mandatory sedation or general anesthesia to prevent movement in almost all patients. It needs a complete evaluation of structurally abnormal heart. The commonly used procedures are angioplasty, valvuloplasty, coil embolization, atrial septostomy, device closure, diagnostic cath studies, and electrophysiological studies.

The results of the study compared DK versus propofol ketamine combinations for hemodynamic stability and recovery time in 60 minutes, and spontaneous breathing children undergoing cardiac catheterization. A decrease in the heart rate in the DK group in the first 25 min after induction was obtained which remained persistant in both the groups till the end of procedure.  There were no significant differences  found in BP, SpO₂ and Respiratory rate between the two groups. These results were similar to studies conducted by Tosun et al. and Ali et al which compared  the effects of DK and PK combinations on hemodynamics, sedation level, and the recovery period in pediatric patients undergoing cardiac catheterization.

Propofol has also been recommended for pediatric cardiac catheterization because of production of rapid emergence. Gozal et al. studied the effects of propofol on the systemic and pulmonary circulations on the pediatric patients scheduled for cardiac catheterization and reported propofol as an adequate sedative agent for pediatric patients undergoing cardiac catheterization. Dexmedetomidine, an alpha 2 agonist,  is a new sedative, analgesic, and anxiolytic agent. Its intraoperative administration decreases anesthetic requirements, speeds up postoperative recovery, and blunts the sympathetic nervous system response to surgical stimulation. Munro et al. reported their experience using dexmedetomidine in 20 children aged 3 months to 10 years undergoing cardiac catheterization and deduced that dexmedetomidine, with or without the addition of propofol, may be a suitable alternative for sedation in spontaneously breathing patients undergoing cardiac catheterization.

Recovery time evaluated in this study was significantly longer in DK group compared to the PK group (40.88±8.19 vs. 22.28±3.63 min) p≤0.05. The consumption of Ketamine boluses was more in DK group than the PK group.  High utilization of ketamine in dexmedetomidine group compared to the propofol group exhibits similarity with a study conducted by Tosun et al. comparing the same drugs in children undergoing minor cardiac procedures in cardiac catheterization laboratory. They showed that ketamine consumption in dexmedetomidine group was more than the propofol group (2.03 vs. 1.25 mg/kg/h). There were no incidences of side effects like bradycardia, oxygen desaturation, hypotension requiring any treatment, convulsions, laryngospasm, agitation, hiccups, shivering, increased oral secretions, nausea, and vomiting in children of both groups.