The edition · Emergency & Critical Care
Two large emergency trials found statistically significant pain differences that fall below what patients notice
Magnesium added to paracetamol raised headache treatment success from 65.1% to 78.9%, and intranasal ketamine beat subcutaneous by 0.72 points — both statistically clear, both under the 1.3-point threshold for clinical importance. What separates them is rescue analgesia and route, not analgesia itself.
The edition in brief
Two well-powered emergency analgesia trials landed today, and both are instructive for the same reason: each reports a statistically significant difference in pain score that sits below the 1.3-point threshold on the numerical rating scale generally accepted as the smallest difference a patient can detect. Intravenous magnesium sulfate added to paracetamol for acute non-traumatic headache, in 1,028 patients, raised treatment success from 65.1% to 78.9% — a 13.8 percentage point difference. But every timed pain-score difference fell below the clinical importance threshold. What the magnesium did deliver was less rescue analgesia, 7.1% against 15.3%, and higher satisfaction, at the cost of slightly more mild adverse events. Intranasal versus subcutaneous ketamine at 20 mg for acute musculoskeletal trauma, in 1,194 patients, gave a mean difference of 0.72 points at 30 minutes favouring intranasal — again below the threshold, at every time point. The authors' conclusion is the correct one: no clinically important difference, which makes route a question of convenience and patient preference rather than efficacy. Also today: phenobarbital-based pathways for alcohol withdrawal in critical care shortened ICU stay by 0.6 days without reducing intubation, on sixteen non-randomised studies. And ACEP has approved multidisciplinary consensus guidelines on unscheduled procedural sedation.
Magnesium for headache: more successes, no meaningful pain difference, less rescue analgesia
Adding intravenous magnesium to paracetamol for acute headache halved the need for rescue analgesia and raised measured success, but produced no pain-score difference large enough for a patient to perceive.
Intranasal ketamine matched subcutaneous for acute trauma pain, so route is now a preference
Intranasal and subcutaneous ketamine at 20 mg produced no clinically important difference in pain relief for acute musculoskeletal trauma, making route a matter of speed, tolerability and access.
Phenobarbital pathways shortened ICU stay for alcohol withdrawal, without reducing intubation
Phenobarbital-based pathways for alcohol withdrawal in critical care shortened ICU stay by about 0.6 days without reducing intubation, on entirely non-randomised evidence.
ACEP has approved consensus guidelines on unscheduled procedural sedation
ACEP has approved two-part multidisciplinary consensus guidelines for unscheduled procedural sedation, covering oversight and quality monitoring as well as clinical practice.
Know your scale's minimum important difference before you read the p value
Before acting on a significant difference in a symptom score, compare the confidence interval to that scale's minimum important difference — a real difference can still be one no patient can feel.
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