No abstract available.
Oximetry*

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

Introduction: Pulse oximetry is frequently utilized as a rapid, non-invasive, point-of-care alternative to arterial blood gas analysis in measuring oxygen saturation of children with pneumonia. Objectives: To compare portable fingertip pulse oximetry saturation (SpO2PF), handheld pulse oximetry saturation (SpO2H) and arterial oxygen saturation (SaO2) in detection of hypoxemia, and correlate hypoxemia with clinical features in children with pneumonia. Methodology: This was a prospective, observational, cross-sectional study involving patients 3 months to 5 years old with pneumonia. Oxygen saturation was measured using a portable fingertip pulse oximeter, a handheld pulse oximeter, and arterial blood gas analysis. Results: Eighty-six children were included. SpO2 PF underestimated oxygen levels by 0.126% (95% CI -0.240 to 0.491), while SpO2H underestimated it by 0.323% (95% CI -0.075 to 0.721). Between portable and handheld readings, the mean difference was 0.198% (95% CI -0.089 to 0.484). Across the three methods, limits of agreement ranged from -3.388 to +4.035%. There was no statistically significant difference in variance among the three measurements. Children with tachypnea (cOR 2.623, 95% CI 1.06 – 6.48, p = 0.037), difficulty breathing (cOR 6.316, 95% CI 1.96 – 20.34, p = 0.002), and subcostal retractions (cOR 2.842, 95% CI 1.05 to 7.69, p = 0.040) were more likely to have hypoxemia. Conclusion Pulse oximetry closely correlates with arterial blood gas analysis within acceptable limits of agreement and with no significant differences in variance among measurements. Difficulty breathing, tachypnea and subcostal retractions were significantly more likely to be observed in hypoxemic children.
Oximetry ; Hypoxia

No abstract available.
Extremities* ; Oximetry* ; Oxygen*

No abstract available.
Heart Septal Defects, Ventricular* ; Oximetry*

Pulse oximetry is a noninvasive, reusable device that is being used routinely in anesthesia procedure for monitoring oxygen saturation. This is a very beneficial device that can quickly detect of hypoxia, the most common cause of anesthesia-related death. However, in clinical uses, false desaturation readings are frequently found to be caused by various factors. Such as by the use of intraoperative blue dye, which can falsely decrease oxygen saturation as determined by pulse oximetry. We therefore report our findings concerning prolonged decreased pulse oximetry readings due to the intraoperative use of blue dye subcutaneously.
Anesthesia ; Anoxia ; Oximetry* ; Oxygen ; Reading

No abstract available.
Humans ; Infant, Newborn* ; Oximetry* ; Oxygen*

A method which combines empirical mode decomposition with wavelet transform is employed to remove breathing baseline draft from pulse wave signal. First of all, this method decomposes pulse wave signal into several intrinsic mode functions and judges the intrinsic mode function which contains the information of breathing baseline draft. And then wavelet transform is used to decompose these intrinsic mode functions, and the detail coefficients representing breathing baseline draft are set into zero. At last, the signal is rebuilt. This can realize removing breathing baseline draft. A self-developed measurement device was used to obtain the pulse wave signal for validating, and AC-DC modulation ratio value was adopted to evaluate the effect. The results showed that this method could effectively remove breathing baseline draft from pulse wave signal.
Algorithms ; Oximetry ; instrumentation ; methods ; Respiration

Anesthesia, Local* ; Oximetry ; Oxygen* ; Tonsillectomy*

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