Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely

Body size trends and recovery amongst bivalves following the end-Triassic mass extinction

Fossils in the immediate aftermath of mass extinctions are often of small size, a phenomenon attributed to the Lilliput Effect (temporary, size reduction of surviving species). There has been little attempt to study size trends during subsequent recovery intervals nor has the relationship between size, diversity and environmental controls been evaluated. Here we examine the recovery following the end-Triassic mass extinction amongst bivalves of the British Lower and Middle Lias. Three distinct phases of size change are seen that are independent of other recovery metrics: initially bivalves are small but the Lilliput Effect is a minor factor, the majority of small taxa belong to new species that undergo a later within-species size increase (the Brobdingnag Effect) throughout the subsequent Hettangian Stage. New species that appeared during the Hettangian were also progressively larger and Cope's Rule (size increase between successive species) is seen – notably amongst ammonites. The size increase was reversed during the Sinemurian Stage, when bivalves once again exhibited small body sizes. During the Pliensbachian Stage another phase of size increase occurred with further evidence of the Brobdingnag Effect. These three phases of size change are seen across all suspension feeding ecological guilds of bivalve but are not expressed among deposit feeders. Local environmental conditions explain some aspects of size patterns, but factors such as temperature, marine oxygenation and sea level, do not correlate with the long-term size trends. The Brobdingnag Effect may reflect increased availability/quality of food during the recovery interval: a factor that controlled bivalve size but not evolution