Measurement of exhaled breath temperature in patients under general anesthesia: A feasibility study.

The aim of the present study was to investigate the respiratory parameters that influence the exhaled breath temperature (EBT) and the feasibility of using the latter to monitor the core temperature under general endotracheal anesthesia. A total of 20 patients undergoing abdominal surgery were included in the present study. At the first stage of the experiment, the respiratory rate was adjusted, while the other respiratory parameters [tidal volume, inspiratory and expiratory time ratio (TI:TE), and positive end expiratory pressure (PEEP)] were maintained at a constant level. At the second stage, the tidal volume was adjusted, while the other respiratory parameters were maintained at a constant level. At the third stage, the TI:TE was adjusted, while the other parameters were maintained at a constant level. At the fourth stage, PEEP was adjusted, while the other parameters were maintained at a constant level. In each experiment, the EBT, the maximum temperature of exhaled air in each min, the inhaled air temperature and the nasopharyngeal temperature (T nose) were recorded every min. During the first stage of the experiment, no significant difference was noted in the EBT at different levels of respiratory rate. During the second, third and fourth stage, no significant difference was noted in the EBT at different tidal volumes, TI:TE and PEEP, respectively. The EBT was significantly correlated with the T nose. Overall, the present study demonstrated that the EBT of patients undergoing abdominal surgery under general endotracheal anesthesia was not affected by the examined respiratory parameters and that it could be considered a feasible method of monitoring core temperature.

Sedative drugs used for mechanically ventilated patients in intensive care units: a systematic review and network meta-analysis.

BACKGROUND: The effects of different sedative drugs on all-cause mortality rate, duration of ICU stay, and risk of delirium in mechanically ventilated ICU patients are unclear. This meta-analysis aimed to compare the effectiveness and safety of individual sedative drugs and drug combinations in mechanically ventilated ICU patients. MATERIALS AND METHODS: Medline, Embase, Cochrane, EBSCOhost, and ISI Web of Science databases were searched for studies that assessed sedation in ICU mechanically ventilated patients. A Bayesian random-effects model was used to combine the direct comparisons and indirect evidence. RESULTS: Thirty-one randomized, controlled trials were included, which consisted of 4491 patients who received one of seven sedative drugs or a combination of drugs. There were no significant differences regarding the all-cause mortality rate. Compared to propofol, inhalation anesthetics (hazard ratio [HR] 0.121; 95% credible interval [CrI] -7.58 to 7.62), alpha agonists (HR 2.2; 95% CrI 0.776 to 5.22), propofol with benzodiazepines (HR 0.306; 95% CrI -6.97 to 7.65), ketamine with benzodiazepines (HR 6.57; 95% CrI -6.05 to 19.1) and placebo (HR 2.4; 95% CrI -5.37 to 10.3), benzodiazepines (HR 3.62; 95% CrI 0.834 to 6.2) may increase the duration of ICU stay. Compared to alpha agonists, propofol (HR 2.4; 95% CrI 0.304 to 21.1) and placebo (HR 6.12; 95% CrI 0.745 to 54.6), benzodiazepines (HR 2.59; 95% CrI 1.08 to 7.4) were associated with incremental risks of delirium. CONCLUSION: Compared to propofol, benzodiazepines may increase the duration of ICU stay. Compared to alpha agonists, benzodiazepines were associated with an increased risk of delirium.

Effectiveness of antimicrobial-coated central venous catheters for preventing catheter-related blood-stream infections with the implementation of bundles: a systematic review and network meta-analysis.

BACKGROUND: Catheter-related blood-stream infections (CRBSIs) are the most common complication when using central venous catheters (CVCs). Whether coating CVCs under bundles could further reduce the incidence of CRBSIs is unclear. We aimed to assess the effectiveness of implementing the use of bundles with antimicrobial-coated CVCs for preventing catheter-related blood-stream infections. METHODS: In this systematic review and network meta-analyses, we searched the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library in addition to the EMBASE, MEDLINE, CINAHL, and Web of Science databases for studies published before July 2017. The primary outcome was the rate of CRBSIs per 1000 catheter-days, and the secondary outcome was the incidence of catheter colonization. RESULTS: Twenty-three studies revealed significant differences in the rate of CRBSIs per 1000 catheter-days between antimicrobial-impregnated and standard CVCs (RR 0.70, 95% CI 0.53-0.91, p = 0.008). Thirty-three trials were included containing 10,464 patients who received one of four types of CVCs. Compared with a standard catheter, chlorhexidine/silver sulfadiazine- and antibiotic-coated catheters were associated with lower numbers of CRBSIs per 1000 catheter-days (ORs and 95% CrIs: 0.64 (0.40-0.955) and 0.53 (0.25-0.95), respectively) and a lower incidence of catheter colonization (ORs and 95% CrIs: 0.44 (0.34-0.56) and 0.30 (0.20-0.46), respectively). CONCLUSIONS: Outcomes are superior for catheters impregnated with chlorhexidine/silver sulfadiazine or other antibiotics than for standard catheters in preventing CRBSIs and catheter colonization under bundles. Compared with silver ion-impregnated CVCs, chlorhexidine/silver sulfadiazine antiseptic catheters resulted in fewer cases of microbial colonization of the catheter but did not reduce CRBSIs.

Urine volatile organic compounds as biomarkers for minimal change type nephrotic syndrome.

Urinary volatile organic compounds (VOCs) profiling has recently received considerable attention because it can be obtained noninvasively and conveniently while it can be successfully used in a variety of diseases and can provide unique biomarkers. The aim of current study was to investigate potential biomarkers between minimal change type nephrotic syndrome (MCNS) and normal. Urinary samples were collected from 38 minimal change type nephrotic syndrome patients and 15 healthy controls. Solid phase microextraction (SPME) and chromatography- mass spectrometry (GC-MS) were used to analysis the urinary metabolites. To deal with the final data, the statistical methods principal component analysis (PCA) and orthogonal partial least-squares discriminant analysis (OPLSDA) were performed. Six specific VOC biomarkers were present at abnormal levels in the urine of MCNS patients. These VOCs included trans-2,2-dimethyl-4-decene; pyrrole; carbamic acid, monoammonium salt; 1-butyne, 3,3-dimethyl-; diisopropylamine; and 4-heptanone. These biomarkers may be useful as a new diagnostic method and for monitoring the prognosis for MCNS patients.

Volatile organic metabolites identify patients with gastric carcinoma, gastric ulcer, or gastritis and control patients.

BACKGROUND: Gastric cancer ranks 4th among the most common cancers worldwide, and the mortality caused by gastric cancer is 2nd only to lung cancer. Gastric cancer shows a lack of specific symptoms in its early stages. In addition, its clinical symptoms often do not match the corresponding stage. Upper gastrointestinal endoscopy with biopsy is the gold standard for the diagnosis of gastric cancer because of its high accuracy. However, this operation is invasive, patient compliance is poor, and high demands for medical staff and equipment are typical of this procedure. Recent studies have demonstrated a connection between specific breath volatile organic compounds (VOCs) and various forms of cancers. METHODS: We collected expired air from patients with gastric cancer, chronic atrophic gastritis or gastric ulcers as well as from healthy individuals. Solid-phase microextraction, gas chromatography-mass spectrometry and principal component analysis statistics were applied to identify potential biomarkers of gastric cancer among VOCs. RESULTS: Fourteen differential metabolites were annotated using the NIST 11 database, with a similarity threshold of 70%. Currently, the metabolic origin of VOCs remains unclear; however, several pathways might explain the decreasing or increasing trends that were observed. CONCLUSIONS: The results of this study demonstrate the existence of specific VOC profiles associated with patients with carcinoma. In addition, these metabolites may contribute to the diagnosis and screening of patients with carcinoma.

Mechanical ventilation strategies for intensive care unit patients without acute lung injury or acute respiratory distress syndrome: a systematic review and network meta-analysis.

BACKGROUND: It has been shown that the application of a lung-protective mechanical ventilation strategy can improve the prognosis of patients with acute lung injury (ALI) or acute respiratory distress syndrome (ARDS). However, the optimal mechanical ventilation strategy for intensive care unit (ICU) patients without ALI or ARDS is uncertain. Therefore, we performed a network meta-analysis to identify the optimal mechanical ventilation strategy for these patients. METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library, EMBASE, MEDLINE, CINAHL, and Web of Science for studies published up to July 2015 in which pulmonary compliance or the partial pressure of arterial oxygen/fraction of inspired oxygen (PaO2/FIO2) ratio was assessed in ICU patients without ALI or ARDS, who received mechanical ventilation via different strategies. The data for study characteristics, methods, and outcomes were extracted. We assessed the studies for eligibility, extracted the data, pooled the data, and used a Bayesian fixed-effects model to combine direct comparisons with indirect evidence. RESULTS: Seventeen randomized controlled trials including a total of 575 patients who received one of six ventilation strategies were included for network meta-analysis. Among ICU patients without ALI or ARDS, strategy C (lower tidal volume (VT) + higher positive end-expiratory pressure (PEEP)) resulted in the highest PaO2/FIO2 ratio; strategy B (higher VT + lower PEEP) was associated with the highest pulmonary compliance; strategy A (lower VT + lower PEEP) was associated with a shorter length of ICU stay; and strategy D (lower VT + zero end-expiratory pressure (ZEEP)) was associated with the lowest PaO2/FiO2 ratio and pulmonary compliance. CONCLUSIONS: For ICU patients without ALI or ARDS, strategy C (lower VT + higher PEEP) was associated with the highest PaO2/FiO2 ratio. Strategy B (higher VT + lower PEEP) was superior to the other strategies in improving pulmonary compliance. Strategy A (lower VT + lower PEEP) was associated with a shorter length of ICU stay, whereas strategy D (lower VT + ZEEP) was associated with the lowest PaO2/FiO2 ratio and pulmonary compliance.

Comparative Analysis of VOCs in Exhaled Breath of Amyotrophic Lateral Sclerosis and Cervical Spondylotic Myelopathy Patients.

Amyotrophic lateral sclerosis (ALS) is an incurable neurological degenerative disease. It can cause irreversible neurological damage to motor neurons; typical symptoms include muscle weakness and atrophy, bulbar paralysis and pyramidal tract signs. The ALS-mimicking disease cervical spondylotic myelopathy (CSM) presents similar symptoms, but analysis of breath volatile organic compounds (VOCs) can potentially be used to distinguish ALS from CSM. In this study, breath samples were collected from 28 ALS and 13 CSM patients. Subsequently, gas chromatography/mass spectrometry (GCMS) was used to analyze breath VOCs. Principal component analysis (PCA) and orthogonal partial least-squares discriminant analysis (OPLSDA) were the statistical methods used to process the final data. We identified 4 compounds with significantly decreased levels in ALS patients compared with CSM controls: (1) carbamic acid, monoammonium salt; (2) 1-alanine ethylamide, (S)-; (3) guanidine, N,N-dimethyl-; and (4) phosphonic acid, (p-hydroxyphenyl)-. Currently, the metabolic origin of the VOCs remains unclear; however, several pathways might explain the decreasing trends observed. The results of this study demonstrate that there are specific VOC profiles associated with ALS and CSM patients that can be used to differentiate between the two. In addition, these metabolites could contribute to a better understanding of the underlying pathophysiological mechanisms of ALS.

Volatile Organic Metabolites Identify Patients with Mesangial Proliferative Glomerulonephritis, IgA Nephropathy and Normal Controls.

Urinary volatile organic compounds (VOCs) analysis for kidney diseases has attracted a large amount of scientific interest recently, and urinary metabolite analysis has already been applied to many diseases. Urine was collected from 15 mesangial proliferative glomerulonephritis (MsPGN) patients, 21 IgA nephropathy (IgAN) patients and 15 healthy controls. Solid phase microextraction-chromatography- mass spectrometry (SPME-GC-MS) was used to analyse the urinary metabolites. The statistical methods principal component analysis (PCA) and orthogonal partial least-squares discriminant analysis (OPLSDA) were performed to process the final data. Five metabolites were significantly greater in the group of MsPGN patients than in the normal control group (P < 0.05) while three metabolites were found at increased levels in the group of IgAN patients compared with the normal controls (P < 0.05). In addition, five metabolites were significantly increased in the group of IgAN patients compared with the MsPGN patients (P < 0.05). These five metabolites may be specific biomarkers for distinguishing between MsPGN and IgAN. The analysis of urinary VOCs appears to have potential clinical applications as a diagnostic tool.