Factors associated with rebound pain after peripheral nerve block for ambulatory surgery.

BACKGROUND: Rebound pain is a common, yet under-recognised acute increase in pain severity after a peripheral nerve block (PNB) has receded, typically manifesting within 24 h after the block was performed. This retrospective cohort study investigated the incidence and factors associated with rebound pain in patients who received a PNB for ambulatory surgery. METHODS: Ambulatory surgery patients who received a preoperative PNB between March 2017 and February 2019 were included. Rebound pain was defined as the transition from well-controlled pain (numerical rating scale [NRS] ≤3) while the block is working to severe pain (NRS ≥7) within 24 h of block performance. Patient, surgical, and anaesthetic factors were analysed for association with rebound pain by univariate, multivariable, and machine learning methods. RESULTS: Four hundred and eighty-two (49.6%) of 972 included patients experienced rebound pain as per the definition. Multivariable analysis showed that the factors independently associated with rebound pain were younger age (odds ratio [OR] 0.98; 95% confidence interval [CI] 0.97-0.99), female gender (OR 1.52 [1.15-2.02]), surgery involving bone (OR 1.82 [1.38-2.40]), and absence of perioperative i.v. dexamethasone (OR 1.78 [1.12-2.83]). Despite a high incidence of rebound pain, there were high rates of patient satisfaction (83.2%) and return to daily activities (96.5%). CONCLUSIONS: Rebound pain occurred in half of the patients and showed independent associations with age, female gender, bone surgery, and absence of intraoperative use of i.v. dexamethasone. Until further research is available, clinicians should continue to use preventative strategies, especially for patients at higher risk of experiencing rebound pain.

Rapid clinical assessment of the sublingual microcirculation - Visual scoring using microVAS in comparison to standard semi-automated analysis.

RATIONALE: Alterations in human microcirculation occur in many disease states leading to morbidity and mortality, however assessing the microcirculation is not standard clinical practice. Standard microcirculation analysis using semi-automated analysis is expensive, time consuming, and expertise dependent making it unfeasible. We proposed a novel visual scoring system (microVAS) for the analysis of microcirculation videos that can be performed at the patient bedside in real time. OBJECTIVE: Validate our microVAS score by training health professionals unfamiliar with the microcirculation field to use our microVAS score and compare their scores to the standard method of semi-automated analysis using AVA3 software. METHODS: Using a prospective double-blind study design, we recruited and trained 20 participants to use our microVAS score. Participants scored 40 videos (from 22 healthy and 18 septic patients) for MFI and PPV. The same 40 videos were analysed by an expert using the gold standard semi-automated method of analysis. The results of the participants and the expert were analysed by Pearson's linear regression. Krippendorff's alpha was used to assess inter-rater reliability of the participants. RESULTS: Overall correlation of MFI was r = 0.33 (95% CI 0.27-0.39), p < 0.05; overall correlation of PPV was r = -0.11 (95% CI -0.18 to -0.04), p < 0.05. The Krippendorff's alpha for MFI was 0.56 (healthy videos: α= 0.34, sepsis videos: α= 0.31). For PPV Krippendorff's alpha was 0.43 (healthy videos: α= 0.56, sepsis videos: α= 0.17). CONCLUSIONS: Overall for both MFI and PPV, there was a small correlation between our microVAS score and AVA 3 scores. Regarding inter-rater reliability both MFI and PPV showed fair agreement between raters. Going forward multiple improvements to the microVAS scoring system as well as the training program are suggested to improve reliability and consistency.

Microcirculation research in community hospitals - challenges and chances.

Community hospitals provide ideal conditions for large clinical studies because of the high volume of unselected patients admitted every year. With regard to microcirculatory studies, there are still some feasibility problems which are not solved yet. First of all, the lack of reliable automated software to analyze microcirculatory images represents the most important issue. Secondly, hardware aspects still need improvements regarding portability and miniaturization. Finally, to conduct studies of the microcirculation in a community hospital is also always a funding issue. The cost of the measurement device is hereby only one factor. Main cost factor is the personnel.

CB2 and GPR55 Receptors as Therapeutic Targets for Systemic Immune Dysregulation.

The endocannabinoid system (ECS) is involved in many physiological processes and has been suggested to play a critical role in the immune response and the central nervous system (CNS). Therefore, ECS modulation has potential therapeutic effects on immune dysfunctional disorders, such as sepsis and CNS injury-induced immunodeficiency syndrome (CIDS). In sepsis, excessive release of pro- and anti-inflammatory mediators results in multi-organ dysfunction, failure, and death. In CIDS, an acute CNS injury dysregulates a normally well-balanced interplay between CNS and the immune system, leading to increased patients' susceptibility to infections. In this review, we will discuss potential therapeutic modulation of the immune response in sepsis and CNS injury by manipulation of the ECS representing a novel target for immunotherapy.

The effect of snus on alcohol-related cigarette administration in dependent and non-dependent smokers.

INTRODUCTION: Alcohol has been found to increase tobacco smoking in both dependent daily smokers (DDS) and nondependent nondaily smokers (NNS), yet little attention has been directed toward examining how different treatments/products modify drinking-related smoking behavior. METHODS: This study examined the acute effects of snus (4mg of nicotine) on alcohol-related smoking responses in 18 DDS and 17 NNS. During each double-blind session, participants were randomly assigned to receive one of the following combinations: alcohol and snus, alcohol and placebo snus, placebo alcohol and snus, or placebo alcohol and placebo snus. Participants consumed their assigned beverage before absorbing their session's product, and after 30min participants could self-administer puffs of their preferred brand of cigarette over a 60-minute period using a progressive ratio task. RESULTS: Alcohol significantly increased tobacco craving (p<.001) and tended to decrease latency to start smoking (p=.021) but only among NNS. In contrast, snus tended to decrease the number of puffs earned and how hard DDS worked for puffs in both beverage conditions (ps≤.019) but it did not alter the smoking behavior of NNS. Craving was not significantly impacted by snus in either type of smoker. DISCUSSION: These findings raise the possibility that different processes mediate alcohol and cigarette co-use in NNS and DDS and suggest that snus may be effective in reducing alcohol-related cigarette use in DDS specifically.