SummaryAspiration of acid into the lungs is an infrequent but potentially devastating complication of general anaesthesia. Routine practice often includes use of pharmacological agents to reduce gastric volume and increase gastric pH. The aim of this study was to compare the net benefit of proton pump inhibitors with histamine 2 blockers in a meta-analysis. Electronic databases were searched for trials that compared ranitidine vs proton pump inhibitors in their effect on volume and pH of gastric fluid aspirates. We identified nine trials of which seven were suitable for meta-analysis. Pooled outcomes suggest that premedication with ranitidine is more effective than proton pump inhibitors in reducing the volume of gastric secretions (by an average of 0.22 ml.kg ; 95% confidence interval 0.04-0.41) and increasing gastric pH (by an average of 0.85 pH units; 95% confidence interval )1.14 to )0.28).

This study was designed to describe the efficacy and toxicity of subcutaneous ketamine infusions and sublingual ketamine lozenges for the treatment of chronic nonmalignant pain. Data were collected prospectively on 70 subjects managed in an academic, tertiary care hospital between 2007 and 2012 who received between 3 and 7 days of subanesthetic, subcutaneous ketamine infusion. Data were analyzed for efficacy, adverse effects, and reduction in use of opioid medication. We also analyzed whether subsequent treatment with sublingual ketamine lozenges resulted in longer-term efficacy of the beneficial effects of the initial ketamine infusion. There was a significant reduction in pain intensity measured by numerical rating scale (NRS) from mean of 6.38 before ketamine to 4.60 after ketamine (P < .005) that was sustained for between 3 months and 6 years. In subjects on opioids, there was a significant reduction in opioid use at the end of the ketamine infusion from a mean morphine equivalent dose (MMED) of 216 mg/day before ketamine to 89 mg/day after ketamine (P < .005). The overall reduction in opioid use after ketamine infusion was 59%. No subjects increased their use of opioids during their hospitalization for the ketamine infusion. A small proportion of subjects who responded to the infusion were continued on ketamine lozenges. This group was followed for between 3 months and 2 years. The use of ketamine lozenges after the infusion resulted in 31% of these subjects being able to cease their use of opioids compared with only 6% who did not receive ketamine lozenges. Eleven percent of subjects who received lozenges subsequently increased their opioid usage. Adverse effects were fairly common, but only mild, with 46% of patients experiencing light-headedness and dizziness, 25% tiredness and sedation, 12% headaches, 12% hallucinations, and 8% vivid dreams. Adverse effects were easily managed by reducing the rate of the ketamine infusion. The administration of subanesthetic, subcutaneous ketamine infusion was well tolerated, with mostly mild adverse effects and no serious adverse effects. The infusion provided significant pain relief in subjects who had failed a wide range of pharmacological and cognitive behavioral therapies. In addition, the results indicate that sublingual ketamine lozenges offer a promising therapeutic option for longer-term relief of chronic nonmalignant pain. The ketamine lozenges have been shown to have acceptable storage stability, and the sublingual bioavailability is sufficiently high and reproducible to support its use in this context.

The traditional method of transitioning from methadone to buprenorphine requires a gradual dose reduction to a low dose of 30 mg daily, followed by cessation, and addressing withdrawal symptoms prior to the initiation of buprenorphine. This process can be time-consuming and is also associated with tremendous patient suffering and adverse outcomes. In recent years, several protocols have emerged based on the notion of blunting the shift from full receptor activation to partial receptor activation via an intermediate "bridge". This typically is required for the time period needed for the acting full agonist, methadone, to undergo biotransformation and clearance. In this report, we present an inadvertent case where transdermal fentanyl as a transitional bridge was utilized along with an inducer of methadone's metabolism to speed up the course, and urine acidification to enhance clearance. Our patient was transitioned from moderate-dose methadone, without encountering any withdrawal symptoms in the process, in three days. This method presents yet another option for select candidates, and it allows physicians to individualize methadone-tobuprenorphine transitions.

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Background: Chronic non-malignant pain is a disabling condition that results in a reduction in function and quality of life when inadequately managed. Sublingual ketamine has been shown to be efficacious for use in chronic pain. Despite its use for decades in chronic non-malignant pain, there is no published long-term data on safety, side-effects or adverse drug reactions.Aim: The aim of this case-series is to provide the initial evidence for safety and efficacy in this patient group.Methods: We present a retrospective review of 29 (n = 29) patients from a metropolitan tertiary pain service who have been receiving sublingual ketamine troches/lozenges between the period of 2012 and 2019. Patients were identified from the outpatient pain clinic, who had been admitted for inpatient subcutaneous ketamine infusions as part of opiate detoxification or management of central sensitisation due to a chronic neuropathic pain syndrome. An initial review was performed to check the patient started taking the ketamine troches. Each of these medical records was reviewed manually to extract information to a datasheet.Results: There was a wide range of dosages used from 25 to 600 mg in divided doses.The duration of treatment ranged 2À89 months. There was no association with either the dosage or duration of treatment and frequency of side-effects. There was an overall reduction in the use of opioids, gabapentinoids or benzodiazepines in 59% of patients with 39% having a complete cessation of an analgesic agent. Side-effects were reported in 24%, but only 7% discontinued the treatment due to the side-effect (drowsiness). There were no reports of renal impairment, cystitis or hepatotoxicity.Discussion: This retrospective case-series has demonstrated that sublingual ketamine is a safe and effective analgesic agent to use in chronic non-malignant pain management. It is indicated in a variety of chronic pain conditions and has an excellent safety profile, with no association between the frequency in side-effects and duration of therapy or total daily dosages. The study has also shown that the 'safe' dose may be higher than the previous consensus.