BackgroundMild hypercapnia is permitted during surgeries in sitting position under general anesthesia to maintain cerebral regional oxygen saturation (rSO2). However, since hypoventilation may cause gas exchange impairment, we evaluated effects of mild hypercapnia on lung oxygenation during shoulder arthroscopy in sitting position.Material/MethodsForty patients were randomly allocated to a normocapnia group (ETCO2 35 mmHg, n=20) or a hypercapnia group (45 mmHg, n=20). The mean arterial pressure (MAP), heart rate (HR), and rSO2 were measured 5 min after intubation in supine position (T0), and at 2, 4, 6, 8, 10, 20, 30, 40, 50, and 60 min of remaining in sitting position (T1–10). Arterial blood gas was analyzed at T0 and T5. The oxygenation index (PaO2/FiO2) and dead-space ventilation ratio (Vd/Vt) were calculated.ResultsThere were no differences in PaO2/FiO2 at T0 and T5 between the 2 groups. At T5, the Vd/Vt was higher in the normocapnia group than in the hypercapnia group (p=0.04). The Vd/Vt at T5 increased from T0 in the normocapnia group. The incidence of cerebral desaturation in the hypercapnia group (0/20) was lower than in the normocapnia group (5/20) (p=0.047). Among rSO2, MAP, and HR, only changes in rSO2 over time between the 2 groups differed significantly (p=0.048).ConclusionsMild hypercapnia did not decrease lung oxygenation in sitting position, probably due to attenuation of the increase in dead-space ventilation ratio. Since hypercapnia maintained rSO2 without changes in oxygenation index and hemodynamic parameters, mild hypercapnia should be maintained during shoulder arthroscopy in sitting position under general anesthesia.

Objective The Intular Scope™ (Medical Park, South Korea) (IS) is a video-lighted stylet that can be used for endotracheal intubation with excellent visualization by adding a camera to its end. We compared the efficacy of a direct laryngoscope (DL) with that of the IS based on hemodynamic changes, ease of intubation, and postoperative airway morbidities. Methods Seventy patients with expected normal airways were randomized for intubation using an IS (n = 35) or DL (n = 35). The primary outcome was the mean arterial pressure during intubation. The secondary outcomes were the time to intubation (TTI), percentage of glottic opening (POGO) score, and number of intubation attempts. The incidence and severity of bleeding, hoarseness, and sore throat after intubation were also recorded. Results Hemodynamic changes during intubation were not significantly different between the groups. The TTI was longer in the IS than DL group. The POGO score was higher in the IS than DL group. Hoarseness and sore throat were significantly less severe in the IS than DL group. Conclusions Using the IS did not significantly improve hemodynamics and resulted in a longer TTI. However, the IS was associated with less severe postoperative airway morbidities compared with the DL.