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

Dry machining of T6061 aluminium alloy using titanium carbonitride (TiCN) coated tools

In metal cutting process, the use of cutting fluids, cooling and easy chip removal causes long-term effects of cutting fluids disposal into environment. Research has also proven the health hazards on manufacturing workers who coming in direct contact with cutting fluids. Currently it is highly competitive or end-user of metal workings fluid to reduce cost and improve productivity. Considering the high cost and problems associated with health and safety, it would be desirable if the use of cutting fluids be omitted. This study investigates the flank wear behavior of coated Titanium Carbonitride (TiCN) coated tools in dry and wet machining of T6061 Aluminum alloy with the aim of obtaining the optimum cutting speed for dry and wet machining respectively. By using specific depths of cut 0.2 and 0.6 mm with feed rates of 0.4 and 0.8 mm/rev respectively, the wear was investigated for 3 different high cutting speeds; 290, 360 and 446 mm/min. Results of dry machining was compared with traditional wet machining process. The temperature of tool tip, machining time and tool wear were recorded. Wear rate of the tool increases with the increasing cutting speed and parameters for both dry and wet machining. Wear percentage difference for dry machining was found to be 21-37 % (d = 0.2 mm and f = 0.4 mm/rev) and 41 - 58% (d = 0.6 mm and f = 0.8 mm/rev) higher than wet machining. The optimum cutting speed for both cutting parameters is 446 m/min for dry and wet machining. Tool tip temperature for dry machining is found to be 14 - 16 % higher than wet machining for both cutting parameters. It is observed that dry machining is suitable for high speed intermittent cutting operations