Quantification of exhaled propofol is not feasible during single-lung ventilation using double-lumen tubes: A multicenter prospective observational trial

Background

Volatile propofol can be measured in exhaled air and correlates to plasma concentrations with a time delay. However, the effect of single-lung ventilation on exhaled propofol is unclear. Therefore, our goal was to evaluate exhaled propofol concentrations during single-lung compared to double-lung ventilation using double-lumen tubes.

Methods

In a first step, we quantified adhesion of volatile propofol to the inner surface of double-lumen tubes during double- and single-lumen ventilation in vitro. In a second step, we enrolled 30 patients scheduled for lung surgery in two study centers. Anesthesia was provided with propofol and remifentanil. We utilized left-sided double-lumen tubes to separately ventilate each lung. Exhaled propofol concentrations were measured at 1-min intervals and plasma for propofol analyses was sampled every 20 min. To eliminate the influence of dosing on volatile propofol concentration, exhalation rate was normalized to plasma concentration.

Results

In-vitro ventilation of double-lumen tubes resulted in increasing propofol concentrations at the distal end of the tube over time. In vitro clamping the bronchial lumen led to an even more pronounced increase (Δ AUC +62%) in propofol gas concentration over time. Normalized propofol exhalation during lung surgery was 31% higher during single-lung compared to double-lung ventilation.

Conclusion

During single-lung ventilation, propofol concentration in exhaled air, in contrast to our expectations, increased by approximately one third. However, this observation might not be affected by change in perfusion-ventilation during single-lung ventilation but rather arises from reduced propofol absorption on the inner surface area of the double-lumen tube. Thus, it is only possible to utilize exhaled propofol concentration to a limited extent during single-lung ventilation.

Registration of Clinical Trial

DRKS-ID DRKS00014788 ( www.drks.de ).     

Resistencia a los anestésicos locales: ¿verdad o mito?

The report of anesthetic technique failure is crucial and the etiology of the problem should be determined. We describe a case of locoregional anesthesia failure, in which, after excluding its most common causes, the resistance to local anesthetics was considered as the most probable clinical hypothesis. For this reason, a genetic test was performed, as well as the efficacy of other local anesthetics was evaluated, constituting a different approach in the cases of locoregional anesthesia failure. True resistance to local anesthetics is difficult to diagnose so information about this is scarce in the literature. One of the proposed causes is a mutation of sodium channels where local anesthetics bind. If not recognized, the application of locorregional anesthesia in this patient's condition can lead to unpleasant experiences and unnecessary risks, related to toxic levels of local anesthetics. For this reason, the resistance to local anesthetics should be always precluded in cases of strong clinical suspicion. This approach could be applied in similar cases.     

The Newborn Infant Parasympathetic Evaluation (NIPE™) monitor predicts post-operative pain in children undergoing day-procedures: A prospective observational study

BackgroundPain assessment is essential for the administration of appropriate analgesia. Currently, clinicians use surrogate methods, such as heart rate or behavioural pain scales, to estimate pain in neonates and infants. The Newborn and Infant Parasympathetic Evaluation (NIPE™) monitor aims to provide an objective numeric value (NIPE index) of pain through a continuous assessment of the patient's parasympathetic activity. The aim of this study was to determine if the intraoperative NIPE index monitoring could predict postoperative pain in neonates and infants.MethodsThis prospective observational pilot study included neonates and infants undergoing elective day-surgical procedures (n = 50). Intraoperatively, NIPE indices at 0 (NIPE₀), 10 (NIPE₁₀), 20 (NIPE₂₀), 30 (NIPE₃₀) minutes and at completion of surgery (NIPEe), were recorded; the median NIPE index (NIPEm) was calculated for the entire procedure. Postoperative Face, Legs, Activity, Cry, Consolability (FLACC) scale scores were calculated by the nursing staff blinded to the intraoperative NIPE indices.ResultsLinear regression documented an association between the NIPEm and postoperative FLACC score at 0 (r = 0.31, p = 0.03) and 10 min (r = 0.36, p = 0.01). No significant associations were observed for FLACC scores at 20 (r = 0.21, p = 0.2) and 30 min (r = 0.36, p > 0.9). Multiple regression analysis revealed that intraoperative NIPE₁₀, NIPE₂₀, NIPE₃₀ and NIPEe also predicted the FLACC score at 0 min (p = 0.003).ConclusionThe intraoperative NIPE index is predictive of pain in the immediate postoperative period. This association was lost at 20 min likely due to nursing intervention to administer analgesia. NIPE monitoring could be useful in facilitating postoperative pain management in infants.Level of evidenceII.Type of studyStudy of Diagnostic Test.     

The role of immunosuppressive agents in the management of severe and refractory immune‐related adverse events

The advent of immune checkpoint inhibitors has improved survival in some types of cancer and brought promising prospects to cancer immunotherapy. Despite their clinical benefits, significant off‐target toxicities resulting from the immune system activation have been observed, namely immune‐related adverse events (irAEs), which pose to clinicians a new challenge of optimal management. With steroids being the mainstay of current management of irAEs, immunosuppressive agents are especially indicated for severe or steroid‐refractory cases, based on current immunopathophysiological knowledge and on extrapolations of treatment options for primary autoimmune disorders. This review focuses on the status and recent clinical progress of immunosuppressive agents in the management of severe and steroid‐refractory irAEs.     

Dietary citrus and/or its extracts intake contributed to weight control: Evidence from a systematic review and meta‐analysis of 13 randomized clinical trials

Randomized controlled trials, being published in English and investigating the associations of at least 4 weeks intervention of citrus and/or its extracts on weight loss among adults, were searched from PubMed, Web of Science, Scopus, and Cochrane by June 2019 to conduct a meta‐analysis. Thirteen articles, including 921 participants, were selected and evaluated by modified Jadad scale. Pooled results by the random‐effects model showed that citrus and/or its extracts administration significantly reduced 1.280 kg body weight (95% CI: ?1.818 to ?0.741, p = 0.000, I² = 81.4%), 0.322 kg/m² BMI (95% CI: ?0.599 to ?0.046, p = 0.022, I² = 87.0%), 2.185 cm WC (95% CI: ?3.804 to ?0.566, p = 0.008, I² = 98.3%), and 2.137 cm HC (95% CI: ?3.775 to ?0.500, p = 0.011, I² = 96.2%), respectively, but no significantly decreased effects on WHR and body fat were observed. Subgroup analysis deduced the different effects of study location, intervention duration on body weight associated indices. No publication bias was observed. Our meta‐analysis supported the beneficial effects of citrus and/or its extracts supplement on body weight control, and future well‐designed studies are required to firmly establish the clinical efficacy of citrus and/or its extracts intervention on body weight.     

The effect of soy intervention on insulin‐like growth factor 1 levels: A meta‐analysis of clinical trials

A low insulin‐like growth factor 1 (IGF‐1) level is known to be associated with many disorders. Several studies have shown that soy consumption may influence IGF‐1, but the findings remain inconclusive. In this work, we conducted a systematic review and meta‐analysis to provide a more accurate estimation of the effect of soy consumption on plasma IGF‐1. A comprehensive systematic search was performed in Scopus, Embase, Web of Science, and PubMed/MEDLINE databases from inception until October 2019. Eight studies fulfilled the eligibility criteria. The pooled weighted mean difference (WMD) of the eligible studies was calculated with random‐effects approach. Overall, a significant increment in plasma IGF‐1 was observed following soy intervention (WMD: 13.5 ng/ml, 95% CI: 5.2, 21.8, I² = 97%). Subgroup analyses demonstrated a significantly greater increase in IGF‐1, when soy was administered at a dosage of ≤40 g/day (WMD: 11.7 ng/ml, 95% CI: 10.9 to 12.6, I² = 98%), and when the intervention duration was <12 weeks (WMD: 26.6 ng/ml, 95% CI: 9.1 to 44.1, I² = 0.0%). In addition, soy intervention resulted in a greater increase in IGF‐1 among non‐healthy subjects (WMD: 36 ng/ml, 95% CI: 32.7 to 39.4, I² = 84%) than healthy subjects (WMD: 9.8 ng/ml, 95% CI: 8.9 to 10.7, I² = 90%). In conclusion, this study provided the first meta‐analytical evidence that soy intake may increase IGF‐1 levels, but the magnitude of the increase is dependent on the intervention dosage, duration, and health status of the participants.