OBJECTIVETo establish a method for simultaneous determination of 17 common pesticides in whole blood by solid phase extraction-gas chromatography-mass spectrometry (SPE-GC-MS).

METHODSWhole blood samples were treated by extraction with acetonitrile, and the obtained extract was cleaned up using an Oasis HLB SPE cartridge; pesticides were separated by GC and quantitatively analyzed by MS with selected ion monitoring.

RESULTSThe concentrations of 17 pesticides in whole blood were 1.0-5.0 mg/L, and the recovery rate was 41.3-102.1%, with a relative standard deviation of less than 10%in most pesticides. The 17 pesticides showed a good linear relationship between concentration and peak area within 0.5-5.0 mg/L, with a correlation coefficient of 0.9945-0.9994. The limit of detection and limit of quantification were 0.02-0.05 mg/L and 0.05-0.09 mg/L, respectively.

CONCLUSIONWith this method, 17 pesticides in whole blood can be well separated and determined. This method has high sensitivity, accuracy, and precision and can be used for identification and quantification of multiple pesticides in blood samples.

Blood Chemical Analysis ; methods ; Chromatography, Liquid ; methods ; Gas Chromatography-Mass Spectrometry ; methods ; Humans ; Pesticides ; blood

BACKGROUND: Preanalytical variability, including biological variability and patient preparation, is an important source of variability in laboratory testing. In this study, we assessed whether a regular light meal might bias the results of routine clinical chemistry testing. METHODS: We studied 17 healthy volunteers who consumed light meals containing a standardized amount of carbohydrates, proteins, and lipids. We collected blood for routine clinical chemistry tests before the meal and 1, 2, and 4 hr thereafter. RESULTS: One hour after the meal, triglycerides (TG), albumin (ALB), uric acid (UA), phosphatase (ALP), Ca, Fe, and Na levels significantly increased, whereas blood urea nitrogen (BUN) and P levels decreased. TG, ALB, Ca, Na, P, and total protein (TP) levels varied significantly. Two hours after the meal, TG, ALB, Ca, Fe, and Na levels remained significantly high, whereas BUN, P, UA, and total bilirubin (BT) levels decreased. Clinically significant variations were recorded for TG, ALB, ALT, Ca, Fe, Na, P, BT, and direct bilirubin (BD) levels. Four hours after the meal, TG, ALB, Ca, Fe, Na, lactate dehydrogenase (LDH), P, Mg, and K levels significantly increased, whereas UA and BT levels decreased. Clinically significant variations were observed for TG, ALB, ALT, Ca, Na, Mg, K, C-reactive protein (CRP), AST, UA, and BT levels. CONCLUSIONS: A significant variation in the clinical chemistry parameters after a regular meal shows that fasting time needs to be carefully considered when performing tests to prevent spurious results and reduce laboratory errors, especially in an emergency setting.
Adult ; Alkaline Phosphatase/blood ; *Blood Chemical Analysis ; Blood Urea Nitrogen ; C-Reactive Protein/analysis ; Diagnostic Errors/prevention & control ; Diet/*standards ; Fasting ; Female ; Humans ; Lipids/blood ; Male ; Metals/blood ; Serum Albumin/analysis ; Triglycerides/blood ; Uric Acid/blood

OBJECTIVE: To reveal the significance of continuous transcutaneous carbon dioxide (CO2) level monitoring through reviewing cases which showed a discrepancy in CO2 levels between arterial blood gas analysis (ABGA) and continuous transcutaneous blood gas monitoring. METHOD: Medical record review was conducted retrospectively of patients with neuromuscular diseases who had started home mechanical ventilation between June 2008 and May 2010. The 89 patients underwent ABGA at the 1st hospital day, and changes to their CO2 level were continuously monitored overnight with a transcutaneous blood gas analysis device. The number of patients who initially appeared to show normal PaCO2 through ABGA, yet displayed hypercapnea through overnight continuous monitoring, was counted. RESULTS: 36 patients (40.45%) presented inconsistent CO2 level results between ABGA and continuous overnight monitoring. The mean CO2 level of the 36 patients using ABGA was 37.23+/-5.11 mmHg. However, the maximum and mean CO2 levels from the continuous monitoring device were 52.25+/-6.87 mmHg and 46.16+/-6.08 mmHg, respectively. From the total monitoring period (357.28+/-150.12 minutes), CO2 retention over 45 mmHg was detected in 198.97 minutes (55.69%). CONCLUSION: Although ABGA only reflects ventilatory status at the puncturing moment, ABGA results are commonly used to monitor ventilatory status in most clinical settings. In order to decide the starting point of home mechanical ventilation in neuromuscular patients, continuous overnight monitoring should be considered to assess latent CO2 retention.
Blood Gas Analysis ; Blood Gas Monitoring, Transcutaneous ; Carbon Dioxide ; Humans ; Medical Records ; Neuromuscular Diseases ; Organothiophosphorus Compounds ; Respiration, Artificial ; Respiratory Insufficiency ; Retention (Psychology) ; Retrospective Studies ; Ventilators, Mechanical

BACKGROUND: The monitoring of end-tidal CO2 tension (PETCO2) during high frequency jet ventilation (HFJV) has been unsatisfactory because of a small tidal volume and slow response time of CO2 analyser, although several authors have reported strategies of successful PETCO2 measurement during HFJV. The aim of this study was to assess the validity of tracheal CO2 tension (PtCO2) as a PaCO2 during HFJV. METHODS: We studied 24 patients undergoing laryngomicrosurgery during HFJV (rates: 100/min; I:E= 0.2; driving pressure: 0.25-0.35 MPa) through a 12 Fr. polyethylene injector placed 6-7 cm below the vocal cord. A gas sampling line was placed longitudinally against the injector and they were wrapped with aluminum foil. Continuous capnography was recorded during 20 minutes of HFJV. Every 5 minutes of HFJV, PtCO2 was obtained from the plateau value of CO2 wave after the stopping of JV and arterial blood gas analysis was done at 20 minutes of HFJV comparing PaCO2 to PtCO2. A Pearson's product moment correlation and regression analysis between PtCO2 and PaCO2 and the agreement between the two methods using Bland-Altman method were assessed. RESULTS: A regression analysis (R2=0.928) and a Pearson's product moment correlation (r=0.965, P<0.001) indicated a strong correlation of PtCO2 and PaCO2 during HFJV. The difference against a mean scatter diagram showed a relative good agreement between the two method (mean difference: 1.58 (SD 2.22) mmHg; limit of agreement: 2.86 and -6.02). CONCLUSIONS: PtCO2 obtained from a plateau of CO2 wave on capnography after interruption of HFJV can accurately reflect PaCO2 during HFJV in relative.
Aluminum ; Blood Gas Analysis ; Blood Gas Monitoring, Transcutaneous ; Capnography ; High-Frequency Jet Ventilation* ; Humans ; Polyethylene ; Reaction Time ; Tidal Volume ; Vocal Cords

Insulin resistance is one of the major aggravating factors for metabolic disease. There are many methods available for estimation of insulin resistance which range from complex techniques down to simple indices. For all methods of assessing insulin resistance, it is essential that their validity and reliability be established before using them in clinical investigations. The reference techniques of hyperinsulinemic euglycemic clamp and its alternative,the frequently sampled intravenous glucose tolerance test, are the most reliable methods available for estimating insulin resistance. However, there are many simple methods from which indices can be derived that have been assessed and validated, which include homeostasis model assessment (HOMA) and the quantitative insulin sensitivity check index (QUICKI). Given the increasing number of simple indices of insulin resistance, it may be difficult for clinicians and researchers to select the most appropriate index for their studies. In planning studies on insulin resistance and selecting a suitable index, a number of important factors need to be considered by investigators, the principle one being the nature of the study to be undertaken.
Glucose Clamp Technique ; Glucose Tolerance Test ; Homeostasis ; Humans ; Insulin Resistance* ; Metabolic Diseases ; Reproducibility of Results ; Research Personnel

The authors recommend reference values of blood gas, co-oximetry and acid-base balances in arterial blood of normal people (n=53) by using ABL-520 of radiometer Copenhagen.
Blood Gas Analysis ; Oximetry ; Blood

OBJECTIVETo establish a method for simultaneous determination of 54 elements in whole blood by inductively coupled plasma mass spectrometry (ICP-MS).

METHODSThe whole blood sample was digested with nitric acid and hydrogen peroxide in a water bath at 90°C, and then analyzed by ICP-MS with 0.1% ethanol as an matrix-matching agent.

RESULTSA good linear relationship was achieved when the concentrations of the 54 elements in whole blood were in the standard range (all r >0.999). The recovery rate of the sample plus the standard was between 80% and 106%, and the relative standard deviation was less than 5%. The standard material of whole blood was determined and the results met the certification requirements.

CONCLUSIONThe method is simple, rapid, sensitive, and accurate. It is applicable for simultaneous determination of multi-elements in a large number of whole blood samples.

Blood Chemical Analysis ; methods ; Humans ; Mass Spectrometry

Blood Chemical Analysis ; Humans ; Water Sports ; physiology

OBJECTIVETo investigate the accuracy and potential error range of noninvasive estimation of CO2 pressure (PCO2), arterial O2 pressure (PaO2), and oxygenation index (OI) by measuring the end-tidal CO2 pressure (PETCO2) and pulse oxygen saturation (SpO2) in patients with chronic obstructive pulmonary disease (COPD) and respiratory failure, and assess the feasibility of this method for dynamic monitoring of arterial CO2 pressure (PaCO2) and PaO2 in the primary care facilities where arterial blood gases analysis is not available.

METHODSAll the 30 patients with COPD and respiratory failure received routine clinical treatment including bronchodilators, mucolytics, glucocorticosteroid, antibiotics and oxygen therapy (titrated to keep SpO2 above 90%) for 5-7 days. A subgroup of the patients also received NIPPV treatment. All the patients were tested with both the eupnea method and prolonged expiratory method before and after the treatment to obtain the data of PCO2 and SpO2 were respectively performed before and after treatment.

RESULTSThe PETCO2 with eupnea (PETCO2(Q)) was 50.72-/+8.93 mmHg, significantly lower than PaCO2 (71.25-/+9.08 mmHg, Plt;0.01), but the PETCO2(P) (70.35-/+8.91 mmHg) was comparable with PaCO2 (P>0.05). Similar results were obtained after the treatment. The PETCO2(P) before treatment and after treatment was positively correlated to PaCO2 (r=0.96 and 0.97, respectively, P<0.01). The PaO2(Y) before the treatment derived from the oxygen dissociation curve based on SpO2 measurement was close to SpO2 (59.96-/+1.42 mmHg vs 59.07-/+2.22 mmHg, P>0.05). The OI derived from PaO2 and OI(Y) from PaO2 (Y) was also similar (215.70-/+22.77 vs 219.15-/+24.63, P>0.05). Linear regression analysis showed positive correlations between PaO2(Y) to PaO2 (r=0.81, P<0.01) and between OI(Y) and OI (r=0.95, P<0.01).

CONCLUSIONSIn patients with COPD (especially those with also type II respiratory failure), the modified monitoring method of PCO2 and maintenance of SpO2 above 90% can precisely estimate PaCO2 and PaO2. This method is feasible for clinical noninvasive and dynamic evaluation of respiratory failure in COPD patients, especially in primary care facilities where arterial blood gases analysis is not available.

Aged ; Aged, 80 and over ; Blood Gas Monitoring, Transcutaneous ; Capnography ; Humans ; Male ; Middle Aged ; Oximetry ; Pulmonary Disease, Chronic Obstructive ; blood ; complications ; physiopathology ; Respiratory Insufficiency ; blood ; etiology ; physiopathology ; Tidal Volume

Blood Chemical Analysis ; methods ; Humans ; Metronidazole ; blood ; Spectrophotometry, Ultraviolet