Skeletal Muscle Oxygen Dynamics during Rehabilitation of Children with Congenital Heart Disease: A Comparative Study of Two Cases.

Objectives: The need for early postoperative rehabilitation in patients with congenital heart disease (CHD) is increasing. However, rehabilitation settings in the pediatric intensive care unit (PICU) are usually determined subjectively by therapists. To address the lack of objective measurements, we sought to determine the effectiveness of near-infrared spectroscopy (NIRS) in evaluating skeletal muscles during rehabilitation of patients in the PICU. This case series aimed to clarify the characteristics of skeletal muscle oxygenation during exercise in 2 postoperative patients with CHD.

Methods: The participants were two 6-month-female infant: one had undergone the Yasui operation (Case 1), and the other had undergone a bidirectional Glenn anastomosis (Case 2). Vital signs and tissue oxygen saturation (StO₂) were measured during each exercise task, and the muscle oxygen extraction ratio (MOER), an index of the intramuscular oxygen extraction rate, was calculated. The results were compared between the two cases.

Results: Case 1 showed no significant changes in vital signs, StO₂, or MOER, whereas Case 2 had low oxygen saturation at rest and low StO₂ during the exercise tasks. MOER increased during the exercise tasks.

Conclusions: The results showed that sitting did not impose a strong cardiopulmonary load on postoperative patients. However, in children with cyanotic cardiac disease, such as in Case 2, skeletal muscle oxygenation should be considered, and NIRS monitoring may be useful for safely performing rehabilitation.