PurposePulse oximetry is routinely used to continuously and non-invasively monitor arterial oxygen saturation (SaO2). When oxygen saturation by pulse oximeter (SpO2) overestimates SaO2, hypoxemia may be overlooked. We compared the SpO2 - SaO2 differences among three pulse oximeters in patients with chronic thromboembolic pulmonary hypertension (CTEPH) who spent their daily lives in a poor oxygen state.Material and MethodThis prospective observational study recruited 32 patients with CTEPH undergoing elective cardiac catheterization. As we collected arterial blood samples in the catheter laboratory, SpO2 values were simultaneously recorded. Three pulse oximeters were used on each patient, and SpO2 values were compared with oximetry readings using a blood gas analyzer. To determine the optimal SpO2 value by which to detect hypoxemia (SaO2≦90%), we generated receiver operating characteristic (ROC) curves for each pulse oximeter.ResultThe root mean square of each pulse oximeter was 1.79 (OLV-3100), 1.64 (N-BS), and 2.50 (Masimo Radical). The mean bias (SpO2 - SaO2) for the 90%–95% saturation range was significantly higher for Masimo Radical (0.19 +/- 1.78% [OLV-3100], 0.18 +/- 1.63% [N-BS], and 1.61 +/- 1.91% [Masimo Radical]; p<0.0001). The optimal SpO2 value to detect hypoxemia (SaO2≦90%) was 89% for OLV-3100, 90% for N-BS, and 92% for Masimo Radical.ConclusionWe found that the biases and precision with which to detect hypoxemia differed among the three pulse oximeters. To avoid hypoxemia, the optimal SpO2 should be determined for each pulse oximeter.

Our data suggest that antibodies contained in PC may contribute to the deterioration of respiratory function after PC transfusion, although the diagnoses of TACO and TRALI may have overlapped among the patients with pulmonary distress in this cohort.

It is essential to assure the efficacy of antimicrobials at the initial phase of therapy. However, increasing the volume of distribution (Vd) of hydrophilic antimicrobials in critically ill patients leads to reduced antimicrobial concentration in plasma and tissue, which may adversely affect the efficacy of that therapy. The aim of the present study was to establish a theoretical methodology for setting an appropriate level for initial vancomycin therapy in individual patients based on Acute Physiology and Chronic Health Evaluation (APACHE) II score. We obtained data from patients who received intravenous vancomycin for a suspected or definitively diagnosed Gram-positive bacterial infection within 72 h after admission to the intensive care unit. The Vd and elimination half-life (t 1/2) of vancomycin values were calculated using the Bayesian method, and we investigated the relationship between them and APACHE II score. There were significant correlations between APACHE II scores and Vd/actual body weight (ABW), as well as t 1/2 (r = 0.58, p < 0.05 and r = 0.74, p < 0.01, respectively). Our results suggested that the Vd and t 1/2 of vancomycin could be estimated using the following regression equations using APACHE II score.[Formula: see text] [Formula: see text]We found that APACHE II score was a useful index for predicting the Vd and t 1/2 of vancomycin, and used that to establish an initial vancomycin dosing regimen comprised of initial dose and administration interval for individual patients.

A 62-year-old woman with Wolff-Parkinson-White syndrome was with recent worsening of dyspnea to New York Heart Association functional status Class III. The patient was diagnosed as having central type chronic thromboembolic pulmonary hypertension. By cardiac catheterization, her mean pulmonary artery pressure was 53 mmHg with total pulmonary resistance 2238 dynes·sec·cm−5. After medical therapies with tadalafil, furosemide, ambrisentan, beraprost, and warfarin were initiated, percutaneous transluminal pulmonary angioplasty (PTPA) was performed. Following PTPA, life-threating hypoxemia resulting from postoperative reperfusion pulmonary edema developed. High-flow nasal cannula therapy (HFNC) was applied, and 100% oxygen at 50 L/min of flow was required to keep oxygenation. HFNC was continued for 3 days, and the patient was discharged on 8th postoperative day with SpO2 of 97% on 3 L/min of oxygen inhalation. Because of the simplicity of the technique, the lower cost of equipment, and remarkable patient tolerance to the treatment, we speculate that HFNC can take over the post of noninvasive ventilation as first-line therapy for patients with acute respiratory failure.

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