Optimal carbon dioxide insufflation pressure during robot-assisted thyroidectomy in patients with various benign and malignant thyroid diseases

BACKGROUND Currently, data are not available concerning a safe insufflation pressure that provides a proper view of the surgical field without adverse metabolic and hemodynamic changes in humans undergoing the robot-assisted thyroidectomy bilateral axillo-breast approach (BABA) using the da Vinci robotic surgical system. The purpose of this study was to determine the optimal carbon dioxide (CO₂) insufflation pressure in patients with various benign and malignant thyroid diseases when using the da Vinci robotic surgical system. METHODS A total of 32 patients underwent thyroid surgery at 6 (n = 15), 9 (n = 15), and 12 (n = 2) mmHg. The partial pressure of carbon dioxide (PaCO₂), pH, cardiac output, heart rate, and mean arterial pressure were measured at baseline, 30 min and 1, 1.5, and 2 hours after CO₂ insufflation, and 30 min after desufflation. RESULTS CO₂ insufflation of 12 mmHg caused severe facial subcutaneous emphysema, hypercarbia, and acidosis during robot-assisted thyroidectomy with BABA. The study was stopped before completion for the patients' safety in accordance with the study protocol. Applying 6- or 9- mmHg of CO₂ insufflation pressure caused increases in PaCO₂ and decreases in arterial pH. However, vital signs were stable and pH and PaCO₂ were within the physiologic range during the surgery in the 6- and 9-mmHg groups. CONCLUSIONS We propose that a CO₂ insufflation pressure under 10 mmHg in robot-assisted thyroidectomy with BABA is the optimal insufflation pressure for patient safety.