Perioperative Pain and Addiction Interdisciplinary Network (PAIN): consensus recommendations for perioperative management of cannabis and cannabinoid-based medicine users by a modified Delphi process.

In many countries, liberalisation of the legislation regulating the use of cannabis has outpaced rigorous scientific studies, and a growing number of patients presenting for surgery consume cannabis regularly. Research to date suggests that cannabis can impact perioperative outcomes. We present recommendations obtained using a modified Delphi method for the perioperative care of cannabis-using patients. A steering committee was formed and a review of medical literature with respect to perioperative cannabis use was conducted. This was followed by the recruitment of a panel of 17 experts on the care of cannabis-consuming patients. Panellists were blinded to each other's participation and were provided with rater forms exploring the appropriateness of specific perioperative care elements. The completed rater forms were analysed for consensus. The expert panel was then unblinded and met to discuss the rater form analyses. Draft recommendations were then created and returned to the expert panel for further comment. The draft recommendations were also sent to four independent reviewers (a surgeon, a nurse practitioner, and two patients). The collected feedback was used to finalise the recommendations. The major recommendations obtained included emphasising the importance of eliciting a history of cannabis use, quantifying it, and ensuring contact with a cannabis authoriser (if one exists). Recommendations also included the consideration of perioperative cannabis weaning, additional postoperative nausea and vomiting prophylaxis, and additional attention to monitoring and maintaining anaesthetic depth. Postoperative recommendations included anticipating increased postoperative analgesic requirements and maintaining vigilance for cannabis withdrawal syndrome.

Perioperative Pain and Addiction Interdisciplinary Network (PAIN) clinical practice advisory for perioperative management of buprenorphine: results of a modified Delphi process.

Until recently, the belief that adequate pain management was not achievable while patients remained on buprenorphine was the impetus for the perioperative discontinuation of buprenorphine. We aimed to use an expert consensus Delphi-based survey technique to 1) specify the need for perioperative guidelines in this context and 2) offer a set of recommendations for the perioperative management of these patients. The major recommendation of this practice advisory is to continue buprenorphine therapy in the perioperative period. It is rarely appropriate to reduce the buprenorphine dose irrespective of indication or formulation. If analgesia is inadequate after optimisation of adjunct analgesic therapies, we recommend initiating a full mu agonist while continuing buprenorphine at some dose. The panel believes that before operation, physicians must distinguish between buprenorphine use for chronic pain (weaning/conversion from long-term high-dose opioids) and opioid use disorder (OUD) as the primary indication for buprenorphine therapy. Patients should ideally be discharged on buprenorphine, although not necessarily at their preoperative dose. Depending on analgesic requirements, they may be discharged on a full mu agonist. Overall, long-term buprenorphine treatment retention and harm reduction must be considered during the perioperative period when OUD is a primary diagnosis. The authors recognise that inter-patient variability will require some individualisation of clinical practice advisories. Clinical practice advisories are largely based on lower classes of evidence (level 4, level 5). Further research is required in order to implement meaningful changes in practitioner behaviour for this patient group.

A Comprehensive Clinical Care Pathway for Microvascular Maxillofacial Reconstructive Surgery.

PURPOSE: Clinical care pathways (CCPs) for major surgical procedures are less developed. We describe the development of a comprehensive microvascular maxillofacial reconstruction CCP and evaluate the impact. MATERIALS AND METHODS: Our team developed a comprehensive CCP for patients undergoing microvascular free flap reconstruction for benign or malignant tumors. Patient data before (n = 48) and after (n = 47) implementation of the CCP were used to evaluate the impact. Bayesian negative binomial and logistic regression analyses were used to estimate the associations between the CCP and clinical outcomes (length of stay [LOS], readmission to the operating room, and readmission within 3 months of discharge). RESULTS: The average total hospital LOS was high in the pre-CCP group (16.9 days) compared with the post-CCP group (9.8 days). Being in the post-CCP group reduced the LOS in the intensive care unit and surgical ward and reduced the risk of readmission to the operating room. CONCLUSION: Our results underscore the importance of standardized evidence-based patient care through CCPs for complex patient populations.

Metabolic flux analysis of Cyanothece sp. ATCC 51142 under mixotrophic conditions.

Cyanobacteria are a group of photosynthetic prokaryotes capable of utilizing solar energy to fix atmospheric carbon dioxide to biomass. Despite several "proof of principle" studies, low product yield is an impediment in commercialization of cyanobacteria-derived biofuels. Estimation of intracellular reaction rates by (13)C metabolic flux analysis ((13)C-MFA) would be a step toward enhancing biofuel yield via metabolic engineering. We report (13)C-MFA for Cyanothece sp. ATCC 51142, a unicellular nitrogen-fixing cyanobacterium, known for enhanced hydrogen yield under mixotrophic conditions. Rates of reactions in the central carbon metabolism under nitrogen-fixing and -non-fixing conditions were estimated by monitoring the competitive incorporation of (12)C and (13)C from unlabeled CO2 and uniformly labeled glycerol, respectively, into terminal metabolites such as amino acids. The observed labeling patterns suggest mixotrophic growth under both the conditions, with a larger fraction of unlabeled carbon in nitrate-sufficient cultures asserting a greater contribution of carbon fixation by photosynthesis and an anaplerotic pathway. Indeed, flux analysis complements the higher growth observed under nitrate-sufficient conditions. On the other hand, the flux through the oxidative pentose phosphate pathway and tricarboxylic acid cycle was greater in nitrate-deficient conditions, possibly to supply the precursors and reducing equivalents needed for nitrogen fixation. In addition, an enhanced flux through fructose-6-phosphate phosphoketolase possibly suggests the organism's preferred mode under nitrogen-fixing conditions. The (13)C-MFA results complement the reported predictions by flux balance analysis and provide quantitative insight into the organism's distinct metabolic features under nitrogen-fixing and -non-fixing conditions.

Role of extracellular protease in nitrogen substrate management during antibiotic fermentation: a process model and experimental validation.

Kinetics of extracellular protease (ECP) production has typically been studied for processes that involve protease as a product. We argue that ECP is equally important in fermentations where protease is not a product of interest. Industrial fermentations typically use complex nitrogen substrates, which are proteolytically hydrolyzed to amino acids (AA) by ECP before assimilation. However, high AA concentrations may lead to nitrogen catabolite repression (NCR) of the products such as antibiotics. Thus, ECP plays a crucial role in managing the nitrogen substrate supply thereby affecting the antibiotic productivity. Here, we have studied the induction of ECP and its effect on the antibiotic productivity for a rifamycin B overproducer strain Amycolatopsis meditterranei S699. This organism produces ECP at the level of 14 U mL(-1) in complex media, which is sufficient for hydrolysis of proteins in the media but low compared to other ECP overproducers. We find ECP secretion to be repressed by ammonia, AA, and under conditions that support high growth rate. We propose a structured kinetic model which accounts for the kinetics of ECP secretion, amino acid availability, growth, and antibiotic production. In addition to the quantity, the timing of ECP induction was critical in achieving higher rifamycin productivity. We artificially created conditions that led to delayed protease secretion, which in turn led to premature termination of batch and lower productivity. The predictive value of the model can be useful in better management of the available nitrogen supply, minimization of NCR, and in the monitoring of fermentation batches.

The COSMIC Bubble Helmet: A Non-Invasive Positive Pressure Ventilation System for COVID-19.

Goal: COSMIC Medical, a Vancouver-based open-source volunteer initiative, has designed an accessible, affordable, and aerosol-confining non-invasive positive-pressure ventilator (NIPPV) device, known as the COSMIC Bubble Helmet (CBH). This device is intended for COVID-19 patients with mild-to-moderate acute respiratory distress syndrome. System Design: CBH is composed of thermoplastic polyurethane, which creates a flexible neck seal and transparent hood. This device can be connected to wall oxygen, NIPPVs including Continuous Positive Airway Pressure and Bi-level Positive Airway Pressure, and mechanical ventilators. Discussion: Justification of CBH design components relied on several factors, predominantly the safety and comfort of patients and healthcare providers. Conclusion: CBH has implications within and outside of the pandemic, as an alternative to invasive mechanical ventilation methods. We have experimentally verified that CBH is effective in minimizing aerosolization risks and performs at specified clinical requirements.

Condom catheter induced penile skin erosion.

Condom catheters are known to be discrete, reliable, comfortable and very easy to use which makes them preferable to bladder catheter (Saint et al. (Urinary catheters: What type do men and their nursesprefer? J Am Geriatr SOC 1999;47:1453-1457); Hirsh et al. (Do condom catheter collecting systems cause urinary tract infection? J Am Med Assoc 1979;2:0-1)). Condom catheters are widely used in the management of male urinary incontinence, bedridden patient and geriatric population. They are considered to be safe, however, they are associated with complications in care of an incorrect use. In our hospital setup a 73-year-old male bedridden patient attended the surgical opd with complain of penile skin erosion following condom catheter application for 4 days for which dressing was done to remove the slough for 2 days then circumcision was done. Henceforth, although a less known complications are associated with the condom catheter but if not attended promptly can lead to a grave condition like penile gangrene, necrosis, death (Özkan et al. (Penile strangulation and necrosis due to condom catheter. Int Wound J 2015;12:248-9. doi: 10.1111/iwj.12102. Epub 2013 Jun 11); Johnson (The condom catheter: urinary tract infection and other complications. South Med J 1983;76:579-82)).

Ultrasound imaging for popliteal sciatic nerve block.

BACKGROUND AND OBJECTIVES: Ultrasound is a novel method of nerve localization but its use for lower extremity blocks appears limited with only reports for femoral 3-in-1 blocks. We report a case series of popliteal sciatic nerve blocks using ultrasound guidance to illustrate the clinical usefulness of this technology. CASE REPORT: The sciatic nerve was localized in the popliteal fossa by ultrasound imaging in 10 patients using a 4- to 7-MHz probe and the Philips ATL HDI 5000 unit. Ultrasound imaging showed the sciatic nerve anatomy, the point at which it divides, and the spatial relationship between the peroneal and tibial nerves distally. Needle contact with the nerve(s) was further confirmed with nerve stimulation. Circumferential local anesthetic spread within the fascial sheath after injection appears to correlate with rapid onset and completeness of sciatic nerve block. CONCLUSIONS: Our preliminary experience suggests that ultrasound localization of the sciatic nerve in the popliteal fossa is a simple and reliable procedure. It helps guide block needle placement and assess local anesthetic spread pattern at the time of injection.

A qualitative systematic review of the role of N-methyl-D-aspartate receptor antagonists in preventive analgesia.

UNLABELLED: We evaluated in a qualitative systematic review the effect of N-methyl-D-aspartate (NMDA) receptor antagonists on reducing postoperative pain and analgesic consumption beyond the clinical duration of action of the target drug (preventive analgesia). Randomized trials examining the use of an NMDA antagonist in the perioperative period were sought by using a MEDLINE (1966-2003) and EMBASE (1985-2003) search. Reference sections of relevant articles were reviewed, and additional articles were obtained if they evaluated postoperative analgesia after the administration of NMDA antagonists. The primary outcome was a reduction in pain, analgesic consumption, or both in a time period beyond five half-lives of the drug under examination. Secondary outcomes included time to first analgesic request and adverse effects. Forty articles met the inclusion criteria (24 ketamine, 12 dextromethorphan, and 4 magnesium). The evidence in favor of preventive analgesia was strongest in the case of dextromethorphan and ketamine, with 67% and 58%, respectively, of studies demonstrating a reduction in pain, analgesic consumption, or both beyond the clinical duration of action of the drug concerned. None of the four studies examining magnesium demonstrated preventive analgesia. IMPLICATIONS: We evaluated, in a qualitative systematic review, the effect of N-methyl D-aspartate antagonists on reducing postoperative pain and analgesic consumption beyond the clinical duration of action of the target drug (preventive analgesia). Dextromethorphan and ketamine were found to have significant immediate and preventive analgesic benefit in 67% and 58% of studies, respectively.