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 (CO(2)) 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 (PaCO(2)), pH, cardiac output, heart rate, and mean arterial pressure were measured at baseline, 30 min and 1, 1.5, and 2 hours after CO(2) insufflation, and 30 min after desufflation. RESULTS: CO(2) 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 CO(2) insufflation pressure caused increases in PaCO(2) and decreases in arterial pH. However, vital signs were stable and pH and PaCO(2) were within the physiologic range during the surgery in the 6- and 9-mmHg groups. CONCLUSIONS: We propose that a CO(2) insufflation pressure under 10 mmHg in robot-assisted thyroidectomy with BABA is the optimal insufflation pressure for patient safety.