Relationship between perfusion index and central temperature before and after induction of anesthesia in laparoscopic gastrointestinal surgery: A prospective cohort study.

The perfusion index (PI) cutoff value before anesthesia induction and the ratio of PI variation after anesthesia induction remain unclear. This study aimed to clarify the relationship between PI and central temperature during anesthesia induction, and the potential of PI in individualized and effective control of redistribution hypothermia. This prospective observational single center study analyzed 100 gastrointestinal surgeries performed under general anesthesia from August 2021 to February 2022. The PI was measured as peripheral perfusion, and the relationship between central and peripheral temperature values was investigated. Receiver operating characteristic curve analysis was performed to identify baseline PI before anesthesia, which predicts a decrease in central temperature 30 minutes after anesthesia induction, and the rate of change in PI that predicts the decrease in central temperature 60 minutes after anesthesia induction. In cases with a central temperature decrease of ≥ 0.6°C after 30 minutes, the area under the curve was 0.744, Youden index was 0.456, and the cutoff value of baseline PI was 2.30. In cases with a central temperature decrease of ≥ 0.6°C after 60 minutes, the area under curve was 0.857, Youden index was 0.693, and the cutoff value of the PI ratio of variation after 30 minutes of anesthesia induction was 1.58. If the baseline PI is ≤ 2.30 and the PI 30 minutes after anesthesia induction is at least 1.58-fold the PI ratio of variation, there is a high probability of a central temperature decrease of at least 0.6°C within 30 minutes after 2 time points.

[Analysis of the Factors in Successful Helmet Non-invasive Positive Pressure Ventilation].

BACKGROUND: Non-invasive positive pressure ventilation (NPPV) reduces the incidences of ventilator-associated pneumonia, the duration of ICU stay and the mortality rate compared with conventional respiratory management of the patients with acute respiratory failure (ARF). Recently, helmet NPPV equipment became available. Because of the high tolerability, the helmet seems to be the best NPPV interface when prolonged and continuous assistance is needed. In this study, we analyzed several factors related to failure of helmet NPPV in ARF patients in intensive care unit (ICU), retrospectively. METHODS: Institutional Research Committee of Nagasaki Rosai Hospital approved this study. We studied consecutive patients with ARF who needed ventilator support in ICU from February 2012 to February 2013. We excluded the patients whose trachea had been intubated before admission to ICU and comatose patients. After admission to ICU, all ARF-patients received helmet NPPV and conventional intensive care therapy including sedation with dexmedetomidine and vasoactive agents. General clinical data including blood gas analysis were recorded at admission to ICU and during ICU stay. Patient's tracheas were intubated if they met at least one of the following criteria, as judged after they had received helmet NPPV: lack of improvement in arterial blood pH or PaCO2; changes in mental status, in patients unable to tolerate noninvasive ventilation; a decrease in SaO2 to less than 85% despite the use of a high FIO2. The final decision of endotracheal intubation was made by a staff intensivist. We defined the failure of helmet NPPV as the execution of endotracheal intubation. The data were presented as median (IQR), and statistical analysis was performed using Mann-Whitney U-test and Fisher's exact probability test at the P<0.05 level of significance. RESULTS: The subjects were 36 patients (25 males and 11 females) aged 27 to 94 years, including 6 patients with acute heart failure (AHF), 8 with pneumonia, 6 with aspiration pneumonia, 2 with hemothorax, 10 with acute respiratory distress syndrome (ARDS), 1 with asthma, and 3 with acute exacerbation of chronic obstructive pulmonary disease (COPD). NPPV was successful in 29 (19 males and 10 females), but unsuccessful in 7 patients (6 males and 1 female). There were no significant differences in demographic data and the variables before induction of NPPV between the successful and unsuccessful groups. The P/F ratio was improved from 133 (99,167) to 209 (143,274) in the successful group, and from 93 (81,157) to 188 (129,271) in the unsuccessful group after the induction of NPPV, but there was no significant difference between the two groups. In the patients with unsuccessful NPPV, expiratory positive airway pressure, inspiratory positive airway pressure, respiratory rate, body temperature and FIO2 before removing NPPV were significantly higher, and ICU stay was longer compared with the patients with successful NPPV. Furthermore, marked excretion of sputum was observed in 4 of the 7 patients with unsuccessful NPPV. CONCLUSIONS: Helmet NPPV improved oxygenation in ARF patients immediately after induction of NPPV. Although there were no significant predictable parameters of unsuccessful NPPV before induction of NPPV, a lot of excretion of sputum might be suggested as a risk factor.

Reduction in soluble guanylyl cyclase-specific activity following prolonged treatment of porcine pulmonary artery with nitric oxide.

In a newly characterized cultured porcine pulmonary artery (PA) preparation, 24-h treatment with the nitric oxide (NO) donor (Z)-1-[N-(2-aminoethyl)-N-(2-ammonioethyl)amino]diazen-1-ium-1,2-diolate (DETA-NO) decreased the response to acutely applied DETA-NO compared with 24-h control (-log EC(50) 6.55 +/- 0.12 and 5.02 +/- 0.21, respectively). Treatment of PA with the cell-permeable superoxide dismutase mimetic, Mn(III) tetra(4-benzoic acid) porphyrin chloride, did not change NO responsiveness in either freshly prepared or 24-h DETA-NO-treated PA. cGMP and cAMP phosphodiesterase activities were approximately equal in PA. Twenty-four-hour DETA-NO treatment did not change either cGMP or cAMP phosphodiesterase activities. Twenty-four hours in culture had no significant effect on soluble guanylyl cyclase (sGC) subunit mRNA expression, but 24-h DETA-NO treatment significantly decreased the expression of both sGCalpha(1) and sGCbeta(1). sGCbeta(1) protein expression was 42 +/- 4 ng/mg soluble protein. Twenty-four hours in culture without and with DETA-NO reduced sGCbeta(1) protein expression (36 +/- 3 and 31 +/- 3 ng/mg soluble protein, respectively, P < 0.025). Basal tissue cGMP [(cGMP)(i)] was significantly increased, and NO-induced (cGMP)(i) was significantly decreased by 24-h DETA-NO treatment. (cGMP)(i) normalized to the amount of sGC protein expressed in PA was significantly lower in PA treated for 24 h with DETA-NO compared with both freshly isolated and 24-h cultured PA. We conclude that prolonged NO treatment induces decreased acute NO responsiveness in part by decreasing both sGC expression and sGC-specific activity.

Nitric oxide sensitivity in pulmonary artery and airway smooth muscle: a possible role for cGMP responsiveness.

We aimed to assess intrinsic smooth muscle mechanisms contributing to greater nitric oxide (NO) responsiveness in pulmonary vascular vs. airway smooth muscle. Porcine pulmonary artery smooth muscle (PASM) and tracheal smooth muscle (TSM) strips were used in concentration-response studies to the NO donor (Z)-1-[N-2-aminoethyl-N-(2-ammonioethyl)amino]diazen-1-ium-1,2-diolate (DETA-NO). PASM consistently exhibited greater relaxation at a given DETA-NO concentration (NO responsiveness) than TSM NO responsiveness, with DETA-NO log EC(50) being -6.55 +/- 0.11 and -5.37 +/- 0.13 for PASM and TSM, respectively (P < 0.01). We determined relationships between tissue cGMP concentration ([cGMP](i)) and relaxation using the particulate guanylyl cyclase agonist atrial natriuretic peptide. Atrial natriuretic peptide resulted in nearly complete relaxation, with no detectable increase in [cGMP](i) in PASM and only 20% relaxation (10-fold increase in [cGMP](i)) in TSM, indicating that TSM is less cGMP responsive than PASM. Total cGMP-dependent protein kinase I (cGKI) mRNA expression was greater in PASM than in TSM (2.23 +/- 0.36 vs. 0.93 +/- 0.31 amol mRNA/mug total RNA, respectively; P < 0.01), but total cGKI protein expression was not significantly different (0.56 +/- 0.07 and 0.49 +/- 0.04 ng cGKI/mug protein, respectively). The phosphotransferase assay for the soluble fraction of tissue homogenates demonstrated no difference in the cGMP EC(50) between PASM and TSM. The maximal phosphotransferase activity indexed to the amount of total cGKI in the homogenate differed significantly between PASM and TSM (1.61 +/- 0.15 and 1.04 +/- pmol.min(-1).ng cGKI(-1), respectively; P < 0.05), suggesting that cGKI may be regulated differently in the two tissues. A novel intrinsic smooth muscle mechanism accounting for greater NO responsiveness in PASM vs. TSM is thus greater cGMP responsiveness from increased cGKI-specific activity in PASM.

Cyclic flow-injection analysis for the repetitive determination of zinc with 2-(5-bromo-2-pyridylazo)-5-[N-n-propyl-N-(3-sulfopropyl)amino]phenol and EDTA.

A circulatory flow-injection method (cyclic FIA) for the repetitive determination of zinc has been proposed. The procedure involves the use of 2-(5-bromo-2-pyridylazo)-5-[N-n-propyl-N-(3-sulfopropyl)amino]phenol (5-Br-PAPS) together with EDTA as a reagent carrier solution, which is recycled in a single-line flow system via a reservoir. The formed 5-Br-PAPS-Zn(II) complex was measured spectrophotometrically at 552 nm, and the signal intensity corresponded to the zinc concentration. After passing through a flow-through cell, the carrier stream then returned to the reservoir, and the main reagent, 5-Br-PAPS, was successfully regenerated by a ligand-exchange reaction with EDTA, allowing the repetitive determination of zinc. The calibration curve for zinc was linear in the concentration range from 0.4 to 10.0 mg dm(-3) with a correlation coefficient of 0.9995 (n = 6). The detection limit of this method was 0.02 mg dm(-3) (S/N= 3). This method allowed as many as 300 repetitive determinations of 2.0 mg dm(-3) zinc solution with only 100 cm3 of the circulating carrier solution, providing a reduction in the consumption of reagents and an elimination of waste, an important approach towards clean chemistry.

Neurological evaluation by intraoperative wake-up during carotid endarterectomy under general anesthesia.

Although general anesthesia allows relief from stressors such as pain, discomfort, or anxiety for patients undergoing carotid endarterectomy, neurologic assessment is less reliable than under local anesthesia. We describe a unique anesthetic management strategy for carotid endarterectomy patients incorporating the advantages of both general and local anesthesia. The technique allows thorough assessment of neurologic function during carotid cross-clamping by intraoperative wake-up, and guarantees airway management by tracheal intubation.