- Design
- Prospective, randomised, placebo-controlled trial, 1:1 allocation
- Population
- Adults undergoing elective laparoscopic radical resection for colorectal cancer; sample size not stated in the published abstract
- Primary outcome
- Hospital Anxiety and Depression Scale score on postoperative day 1
- Effect
- HADS-anxiety and HADS-depression lower on days 1 and 3, and 24-hour IL-6 lower, all P less than 0.05; no effect sizes reported
Anxiety and low mood in the first days after cancer surgery are common, under-treated and rarely an anaesthetic target. This randomised, placebo-controlled trial tested whether esketamine, given as 0.5 mg/kg at induction and 1 mg/kg added to patient-controlled intravenous analgesia, changes them after laparoscopic radical resection for colorectal cancer. The primary outcome was the Hospital Anxiety and Depression Scale on the first postoperative day.
The reported result is that both HADS-anxiety and HADS-depression scores were lower in the esketamine arm on days 1 and 3, that 24-hour interleukin-6 was lower, and that patient satisfaction was higher, all at P less than 0.05.
That is the whole of it. No means, no differences, no confidence intervals, and no sample size in the abstract. A statement that a difference was significant, without the difference, cannot tell you whether the effect is worth the drug — and esketamine is not free of cost, whether counted as emergence phenomena, haemodynamic change, or controlled-drug handling. The direction is consistent with what the antidepressant literature would predict and with other perioperative esketamine work, which is a reason to take the question seriously, not a reason to treat this trial as the answer. The day-7 outcome was collected and is not reported as significant, which is worth noting: an effect that has gone by a week may not be the effect you were hoping to buy.
- Do not add esketamine to a PCIA for mood on the strength of this report.
- Ask about pre-operative anxiety and low mood in cancer surgery — it predicts postoperative pain and length of stay.
- Where esketamine is used for analgesia, record emergence phenomena systematically rather than anecdotally.
- Watch for the full paper: significance without effect sizes is not enough to price a drug into a pathway.
Why it matters
It raises a target anaesthetists do not usually aim at: how the patient feels, not just how much they hurt.
Don't overread it
The absence of reported effect sizes means this cannot support a dosing decision.
The statistics, in plain English
P less than 0.05 tells you a difference is unlikely to be chance; it tells you nothing about whether the difference matters. On the HADS, a change of about 1.5 points is usually taken as the smallest that a patient notices, and a trial can reach significance on a difference well below that with enough patients. Without the means and the confidence interval — and without the sample size — there is no way to tell whether this is a clinically meaningful improvement or a statistically detectable one.
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