Paradoxical increase in the PPG amplitude

Background : Although an increase in sympathetic nerve activity is generally associated with a decrease in the photoplethysmography (PPG) amplitude, the present case study demonstrates that nociceptive stimuli, such as tracheal intubation, paradoxically induce an increase in PPG amplitude. To the best of our knowledge, this is the first study to capture an increase in the PPG amplitude in response to sympathetic nerve activation. Case presentation : A 73-year-old woman underwent open surgery. Following anesthesia induction, tracheal intubation was performed, which resulted in increased heart rate and raised blood pressure. While nociception usually decreases the PPG amplitude, the opposite was found. Conversely, the vascular stiffness K value, our research group’s unique monitoring method to quantify the strength of sympathetic activity, increased reflecting increased peripheral vascular resistance. Conclusions : We report a paradoxical case of increased PPG amplitude following tracheal intubation. It is important to note that the PPG amplitude does not always decrease with nociceptive stimuli

Anesthetic management of a patient with methylmalonic acidemia : a case report

Background: Methylmalonic acidemia (MMA) is a metabolic disorder of organic acids and is characterized by the accumulation of methylmalonic acids. Case presentation: The patient was a 19-year-old female diagnosed with severe MMA at 3 days of age, who was scheduled for renal replacement therapy. Preoperatively, there was no evidence of metabolic acidosis or electrolyte abnormalities. Glucose was administered preoperatively following a 6-h fast. Anesthesia was administered using thiamylal, remifentanil, rocuronium, and sevoflurane. After tracheal intubation, the patient underwent an ultrasoundguided bilateral rectus sheath block with ropivacaine. A drop in blood sugar level was treated with 5% glucose. Extubation was performed after intravenous administration of sugammadex. Conclusions: We report the anesthetic management of a patient with MMA using a combination of general anesthesia and rectus sheath block

Monitoring of muscle mass in critically ill patients : comparison of ultrasound and two bioelectrical impedance analysis devices

Background: Skeletal muscle atrophy commonly occurs in critically ill patients, and decreased muscle mass is associated with worse clinical outcomes. Muscle mass can be assessed using various tools, including ultrasound and bioelectrical impedance analysis (BIA). However, the effectiveness of muscle mass monitoring is unclear in critically ill patients. This study was conducted to compare ultrasound and BIA for the monitoring of muscle mass in critically ill patients. Methods: We recruited adult patients who were expected to undergo mechanical ventilation for > 48 h and to remain in the intensive care unit (ICU) for > 5 days. On days 1, 3, 5, 7, and 10, muscle mass was evaluated using an ultrasound and two BIA devices (Bioscan: Malton International, England; Physion: Nippon Shooter, Japan). The influence of fluid balance was also evaluated between each measurement day. Results: We analyzed 93 images in 21 patients. The age of the patients was 69 (interquartile range, IQR, 59–74) years, with 16 men and 5 women. The length of ICU stay was 11 days (IQR, 9–25 days). The muscle mass, monitored by ultrasound, decreased progressively by 9.2% (95% confidence interval (CI), 5.9–12.5%), 12.7% (95% CI, 9.3–16.1%), 18.2% (95% CI, 14.7–21.6%), and 21.8% (95% CI, 17.9–25.7%) on days 3, 5, 7, and 10 (p < 0.01), respectively, with no influence of fluid balance (r = 0.04, p = 0.74). The muscle mass did not decrease significantly in both the BIA devices (Bioscan, p = 0.14; Physion, p = 0.60), and an influence of fluid balance was observed (Bioscan, r = 0.37, p < 0.01; Physion, r = 0.51, p < 0.01). The muscle mass assessment at one point between ultrasound and BIA was moderately correlated (Bioscan, r = 0.51, p < 0.01; Physion, r = 0.37, p < 0.01), but the change of muscle mass in the same patient did not correlate between these two devices (Bioscan, r = − 0.05, p = 0.69; Physion, r = 0.23, p = 0.07). Conclusions: Ultrasound is suitable for sequential monitoring of muscle atrophy in critically ill patients. Monitoring by BIA should be carefully interpreted owing to the influence of fluid change

全身麻酔下の患者の血漿サブスタンスP濃度 : 術後嘔気・嘔吐の有用な指標となる

Background: This study investigated plasma concentrations of substance P (SP) in patients undergoing general anesthesia (GA) and postoperative nausea and vomiting (PONV). This prospective, observational, cohort study included 23 patients who underwent scheduled surgery under general anesthesia. Blood was collected from the radial artery at predetermined time points (15–30 mins prior anesthesia, 15–30 mins after surgery/GA, and 24 h after surgery). PONV, SP concentrations, risk factors, and analgesics used were measured. Findings: Nine of 23 patients experienced PONV. In patients without PONV, SP concentrations significantly decreased (P < 0.0001) at the end of surgery/GA, compared to baseline, and recovered at 24 h after surgery/GA (452.9 ± 146.2 vs. 666.9 ± 176.5 vs. 580.7 ± 168.6 pg/mL, respectively), whereas SP levels were unchanged during surgery/GA and increased at 24 hours after surgery (P = 0.020) in patients with PONV (726.1 ± 167.8 vs. 655.8 ± 168.0 vs. 779.7 ± 220.7 pg/mL, respectively). Conclusions: These finding suggest that SP levels may be utilized as an objective marker for PONV

Branched-chain amino acids-induced cardiac protection against ischemia/reperfusion injury

Aims: Amino acids, especially branched chain amino acids (BCAAs), have important regulatory roles in protein synthesis. Recently studies revealed that BCAAs protect against ischemia/reperfusion (I/R) injury. We studied the signaling pathway and mitochondrial function affecting a cardiac preconditioning of BCAAs. Main methods: An in vivo model of I/R injury was tested in control, mTOR+/+, and mTOR+/−. Mice were randomly assigned to receive BCAAs, rapamycin, or BCAAs + rapamycin. Furthermore, isolated cardiomyocytes were subjected to simulated ischemia and cell death was quantified. Biochemical and mitochondrial swelling assays were also performed. Key findings: Mice treated with BCAAs had a significant reduction in infarct size as a percentage of the area at risk compared to controls (34.1 ± 3.9% vs. 44.7 ± 2.6%, P = 0.001), whereas mice treated with the mTOR inhibitor rapamycin were not protected by BCAA administration (42.2 ± 6.5%, vs. control, P = 0.015). This protection was not detected in our hetero knockout mice of mTOR. Western blot analysis revealed no change in AKT signaling whereas activation of mTOR was identified. Furthermore, BCAAs prevented swelling which was reversed by the addition of rapamycin. In myocytes undergoing simulated I/R, BCAA treatment significantly preserved cell viability (71.7 ± 2.7% vs. 34.5 ± 1.6%, respectively, p < 0.0001), whereas rapamycin prevented this BCAA-induced cardioprotective effect (43.5 ± 3.4% vs. BCAA, p < 0.0001). Significance: BCAA treatment exhibits a protective effect in myocardial I/R injury and that mTOR plays an important role in this preconditioning effect.This work was supported by JSPS KAKENHI, Japan [grant number 19K09353]

健康成人におけるゼリータイプの炭水化物サプリメント摂取は脂肪組織と筋蛋白質の異化を抑制し満足度を改善した

Background & aims: Many studies have reported the effects of preoperative clear fluid carbohydrate supplements; however, few studies have reported the effects of preoperative jelly-type carbohydrate supplements. This study aimed to assess the effect of a jelly-type oral nutritional supplement (ONS) on metabolism, redox balance by using various surrogate markers and to evaluate its excretion from the stomach. Methods: This study was conducted according to a crossover design. Participants underwent a control experiment whereby they fasted after dinner and only ingested water until the experiment. The remaining participants underwent an ONS experiment whereby they ingested 400 g of ONS before bed and another 400 g at 7:00 am. Blood samples were collected at 9:00 am. After a break of at least 24 h, participants underwent the alternate experiment. Results: Thirty minutes after intake of jelly, the gastric antrum appeared flat (the same result as that at baseline) on ultrasonography. The ONS group showed significantly lower serum free fatty acid levels (100 μEq/L, p = 0.027, vs. 327 μEq/L, n = 6), total ketone bodies levels, 3-MH/creatinine levels, and oxidative stress surrogate markers. Serum insulin levels were significantly higher and participant's satisfaction was improved in the ONS group. Conclusions: We have the limitations of our methodologies as surrogate markers, compared with direct measurement of lipolysis, proteolysis and redox balance regulation. But Jelly-type ONS suppresses the catabolism of adipose tissue and muscle protein, decreases oxidative stress and improves patient satisfaction in healthy participants, without any increased risk of aspiration

High-mass star formation in Orion triggered by cloud-cloud collision II, Two merging molecular clouds in NGC2024

We analyzed the NANTEN2 13CO (J=2-1 and 1-0) datasets in NGC 2024. We found that the cloud consists of two velocity components, whereas the cloud shows mostly single-peaked CO profiles. The two components are physically connected to the HII region as evidenced by their close correlation with the dark lanes and the emission nebulosity. The two components show complementary distribution with a displacement of 0.4 pc. Such complementary distribution is typical to colliding clouds discovered in regions of high-mass star formation. We hypothesize that cloud-cloud collision between the two components triggered the formation of the late O stars and early B stars localized within 0.3 pc of the cloud peak. The collision timescale is estimated to be ~ 10^5 yrs from a ratio of the displacement and the relative velocity 3-4 km s-1 corrected for probable projection. The high column density of the colliding cloud 1023 cm-2 is similar to those in the other massive star clusters in RCW 38, Westerlund 2, NGC 3603, and M42, which are likely formed under trigger by cloud-cloud collision. The present results provide an additional piece of evidence favorable to high-mass star formation by a major cloud-cloud collision in Orion.Comment: 24 pages, 10 figures, submitted for publication in PASJ (cloud-cloud collision special issue