Older patients who received a low dose of dexmedetomidine through a nasal spray had fewer postoperative pulmonary complications than patients given saline in a randomized trial. Complications were recorded within seven days in 9.68% of the dexmedetomidine group and 22.58% of the saline group. The between-group difference was statistically significant, with P = 0.017. That is the main finding of the trial, but it applies only to the study’s treatment schedule and selected population.
The study enrolled 190 people aged 65 or older who were undergoing elective radical thoracoscopic lung-cancer resection at a single center. Four withdrew before receiving the intervention, leaving 186 trial completers, 93 in each group. All randomized participants were included in the intention-to-treat analysis, which preserves the original group assignments in the main calculation. Computer-generated allocation assigned patients in a 1:1 ratio. Patients, surgeons, anesthesiologists and outcome assessors were blinded, and an independent statistician analyzed the data.
What the trial tested
Those assigned to dexmedetomidine received 75 micrograms at 20:00 each night, starting on the night before surgery and continuing through postoperative day 3. The control group received an equal-volume normal saline spray in identical devices at the same times. The primary endpoint was whether a postoperative pulmonary complication, or PPC, occurred within seven days. Secondary measures included the severity and type of complication, IL-6 and TNF-alpha levels, RCSQ sleep scores, the study’s sleep-quality measure, and adverse reactions.
The clearest finding came with caveats
The paper reported an absolute risk reduction of 12.90 percentage points and a number needed to treat of 7.75. In plain terms, the study observed one fewer complication for about every eight patients treated under these conditions. It also reported a risk ratio of 2.333, with a 95% confidence interval from 1.173 to 6.317. Because the paper does not clearly state which group was used as the numerator, that ratio should be read alongside the directly reported group percentages rather than on its own.
The secondary results were more cautious. The distribution of PPC severity grades differed before adjustment, with P = 0.036, but the prespecified Bonferroni correction changed the result to P = 0.072. That correction is an adjustment used when several comparisons are made, and the corrected result was not statistically significant. The trial therefore did not establish a statistically significant difference in complication severity. The reported distribution of pneumonia differed between groups, with P = 0.029, but the researchers did not perform formal inferential testing for that classification under the trial’s fixed-sequence rule, in which the preceding endpoint had to meet the 0.05 threshold before the next key secondary endpoint could be formally tested.
Secondary results pointed in different directions
Several biological and sleep measures moved in the same direction as the main result, although they were secondary outcomes. At the baseline time point, the groups did not differ. From T2 through T4, the dexmedetomidine group had lower IL-6 and TNF-alpha levels and higher RCSQ sleep scores than the saline group. The repeated-measures analysis found group, time and group-by-time effects for these measures, all with P < 0.05. These findings suggest differences in the secondary measures, not a direct measure of whether patients avoided a complication.
The trial also recorded postoperative nausea and vomiting, or PONV, and rescue pain medicine use. Within 72 hours, PONV occurred in 9.30% of the dexmedetomidine group versus 27.91% of the saline group, with P = 0.002. Rescue analgesic use was 20.93% versus 39.53%, with P = 0.007. These were secondary outcomes, so they add context to the trial’s findings but do not replace the primary complication result.
No statistically significant differences were detected in bradycardia, hypotension, excessive sedation, hypoxemia or rescue antiemetic use. All of those comparisons had P > 0.05. That is not the same as proving the regimen was risk-free or that the groups were equivalent on safety; it means only that this trial did not detect a statistically significant difference in the listed events.
The evidence has a narrow reach
This was a single-center trial, and its selected population does not show whether the regimen would work in higher-risk older patients or in broader clinical settings. The primary observation period lasted seven days, so the study did not establish benefits beyond that window. Larger multicenter trials are needed to validate the finding in high-risk patients and determine the best dosing schedule.
The protocol was approved by the hospital ethics committee and registered in the Chinese Clinical Trial Registry as ChiCTR2400090593. The work was supported by the Medical Science and Technology Research Plan Joint Construction Project of Henan Province, grant LHGJ20200059.
Paper data and sources
Original title: Effects of multiple low-dose intranasal dexmedetomidine administration on postoperative pulmonary complications in elderly patients undergoing thoracoscopic radical resection of lung cancer: a single-center randomized controlled trial
Authors: Li B, Liu Y, Liu X et al.
Journal/Repository: Frontiers in pharmacology
Status: Peer-reviewed
First online: 2026-10-19
DOI: Not available
Original paper · Full text