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

Characteristics of oil palm shell biochar and activated carbon prepared at different carbonization times

Palm shells, which are agricultural by-products from palm oil processing, were used to produce low-cost activated carbons. Effect of different carbonization times (1–4 h) on the biochar and activated carbon properties was investigated. The carbonization was carried out at 700°C followed by CO2 activation. Carbons were characterized using Fourier transform infrared spectroscopy, ultimate analysis, scanning electron microscopy (SEM), proximate analysis and nitrogen adsorption. The proximate analysis of the palm shell showed low moisture content (5.5%), high percentage of volatile matter (70%), average contents of fixed carbon (23%) and ash content (4.28%). Carbonization times (1–4 h) within the range investigated have little influence on the char yield, thermal and chemical properties of the material but had more effect on the textural properties. SEM micrographs revealed that more pore networks and cavities were formed after carbonization and activation of the palm shells. The textural characteristics of the biochars and activated carbon reveal that the pore size is predominantly mesoporous. The properties of the palm shell activated carbon prepared at 700°C for 2 h indicated its ability to be used in volatile organics removal from wastewater and in gas-related adsorption applications

Optimization of microwave irradiated - coconut shell activated carbon using response surface methodology for adsorption of benzene and toluene

Effluents from various industries release volatile organic compounds (VOCs) into the environment which causes serious environmental hazards. Coconut shell-based porous carbons were synthesized using chemical activation with potassium hydroxide (KOH) for adsorption of benzene and toluene. Central composite design of the response surface methodology was used in the optimization of the preparation conditions of the porous carbons. The effects of microwave power, irradiation time, and KOH impregnation ratio (IR) on benzene and toluene removal were investigated. The optimum condition was obtained at microwave power of 500 W; irradiation time 4 min; and 1.5 KOH IR, which resulted in 84 and 85% removal of benzene and toluene, respectively, at 95% yield of activated carbon (AC) from the char. Equilibrium data were fitted to Langmuir, Freundlich, and Temkin isotherms with all the models having R2 > 0.94. The equilibrium data were best fitted by Langmuir isotherm, with maximum adsorption capacity of 212 and 238 mg/g for benzene and toluene, respectively. High surface area of 1,354 m2/g and highly microporous carbon prepared lead to the high adsorption capacities. Pseudo-second-order kinetic model best fitted the kinetic data. The ACs produced can be used to remediate water polluted by VOCs