Comparison between insufflation with air or carbon dioxide during the colonoscopy in sedated patients with propofol Comparación entre la insuflación con aire ambiente o con dióxido de carbono durante la colonoscopia en pacientes sedados con propofol

Objectives: compare the intensity of pain experienced after colonoscopy with air or with CO2 and evaluate the safety of CO2 in colonoscopies performed with moderate/deep sedation. Materials and methods: individuals undergoing ambulatory colonoscopy without exclusion criteria (severe respiratory disease, morbid obesity) were randomized in air or CO2 group. We recorded different variables prior to, during and upon completion of the colonoscopy, performing monitoring using pulse oximetry and capnography. Each patient rated, using a visual numeric scale, the intensity of post-colonoscopy pain at different moments. Results: 141 individuals in the air group (sex M/F 63/78, age 24-83) and 129 in the CO2 group (sex M/F 59/70, age 24-82). No significant differences existed in the recorded variables in both groups except for the greater number of explorations performed by an endoscopist in training (TE) in the air group compared to those by a more experienced endoscopist (SE). CO2 in expired air, episodes of oxygen desaturation and of apnoea and dose of propofol, of midazolam were similar in both groups. No episodes of hypercapnea or any complication requiring cardiopulmonary resuscitation measures were recorded. The pain in the air group was significantly higher at 15 minutes and at 1, 3 and 6 hours after the endoscopy, equalising at 24 hours. After multivariant adjustment for type of doctor (TE vs. SE) the differences observed in pain intensity for each group were maintained. Conclusions: a) the use of CO2 in colonoscopy causes significantly less pain in the first 6 hours after the procedure; b) its use in patients with moderate/deep sedation is safe; and c) performance of the endoscopic technique is not modified, nor are times reduced. Objetivos: comparar la intensidad del dolor experimentado tras una colonoscopia con aire ambiente o con dióxido de carbono (CO2) y evaluar la seguridad del CO2 en pacientes con sedación moderada o profunda. Materiales y métodos: individuos sometidos a una colonoscopia ambulatoria, sin enfermedad respiratoria severa ni obesidad mórbida, randomizados a grupo "aire" o "CO2". Se recogieron diferentes variables antes, durante y tras la colonoscopia. Todos los pacientes fueron monitorizados mediante capnografía y pulsioximetría. Posteriormente cada paciente puntuó mediante una escala visual numérica la intensidad del dolor experimentado en diferentes momentos tras la colonoscopia. Resultados: 141 pacientes incluidos en grupo "aire" (hombres/ mujeres 63/78, rango edad 24-83) y 129 en "CO2" (hombres/mujeres 59/70, rango edad 24-82). No e