Adverse events of conscious sedation using midazolam for gastrointestinal endoscopy.

BACKGROUND: This study was conducted to identify the types and incidence of adverse events associated with midazolam, which is the most widely used drug to induce conscious sedation during gastrointestinal endoscopy, and to analyze the factors associated with hypoxemia and sedation failure. METHODS: Of 87,740 patients who underwent gastrointestinal endoscopy between February 2015 and May 2017, the electronic medical records of 335 who reportedly developed adverse events were retrospectively reviewed, and analysis was performed to determine the risk factors for hypoxemia and sedation failure, the two most frequent adverse events among those manifested during gastrointestinal endoscopy. RESULTS: The overall adverse event rate was 0.38% (n = 335); hypoxemia was most frequent, accounting for 40.7% (n = 90), followed by sedation failure (34.8%, n = 77), delayed discharge from the recovery room (22.1%, n = 49), and hypotension (2.2%, n = 5). Compared with the control group, the hypoxemia group did not show any significant differences in sex and body weight, but mean age was significantly older (P < 0.001) and a significantly lower dose of midazolam was administered (P < 0.001). In the group with sedation failure, the mean rate was higher in men (P < 0.001) and a significantly higher dose of midazolam was administered (P < 0.001), but no age difference was found. CONCLUSIONS: Midazolam-based conscious sedation during gastrointestinal endoscopy can lead to various adverse events. In particular, as elderly patients are at higher risk of developing hypoxemia, midazolam dose adjustment and careful monitoring are required in this group.

The effect of interscalene block on ipsilateral shoulder pain and pulmonary function in patients undergoing lung lobectomy: A randomized controlled trial.

BACKGROUND: Postoperative ipsilateral shoulder pain occurs in 37% to 68% of patients undergoing a thoracotomy. We examined whether interscalene brachial plexus block using a lower concentration of local anesthetic would reduce the incidence of post-thoracotomy ipsilateral shoulder pain with assessment of pulmonary function in patients who underwent a lung lobectomy. METHODS: Forty-four patients who underwent a lung lobectomy were randomly assigned to either the control or the interscalene block group. Single-shot interscalene block on the surgical site side was performed using ropivacaine 0.25% 10 mL including dexamethasone 5 mg under ultrasound guidance in the interscalene block group. Lobectomy and continuous paravertebral block were performed under general anesthesia. The presence of ipsilateral shoulder pain and postoperative adverse events were assessed. Pulmonary function tests were performed preoperatively, the day after surgery, and the day after removing the chest tube. RESULTS: The incidence of ipsilateral shoulder pain was significantly lower in the interscalene block group than in the control group (54.5% vs 14.3%, P = .006) with an overall incidence of 34.9%. Postoperative adverse events were similar between the groups, with no patients presenting symptoms of respiratory difficulty. Significant reductions in pulmonary function were observed in all patients after lobectomy; however, no significant difference in any of the pulmonary function test variables was observed postoperatively between the groups. CONCLUSIONS: Interscalene block using 10 mL of 0.25% ropivacaine including dexamethasone 5 mg reduced the incidence of post-thoracotomy ipsilateral shoulder pain and did not result in additional impairment of pulmonary function.