Using arterial-venous oxygen difference to guide red blood cell transfusion strategy.

BACKGROUND: Guidelines recommend a restrictive red blood cell transfusion strategy based on hemoglobin (Hb) concentrations in critically ill patients. We hypothesized that the arterial-venous oxygen difference (A-V O2diff), a surrogate for the oxygen delivery to consumption ratio, could provide a more personalized approach to identify patients who may benefit from transfusion. METHODS: A prospective observational study including 177 non-bleeding adult patients with a Hb concentration of 7.0-10.0 g/dL within 72 h after ICU admission. The A-V O2diff, central venous oxygen saturation (ScvO2), and oxygen extraction ratio (O2ER) were noted when a patient's Hb was first within this range. Transfusion decisions were made by the treating physician according to institutional policy. We used the median A-V O2diff value in the study cohort (3.7 mL) to classify the transfusion strategy in each patient as "appropriate" (patient transfused when the A-V O2diff > 3.7 mL or not transfused when the A-V O2diff ≤ 3.7 mL) or "inappropriate" (patient transfused when the A-V O2diff ≤ 3.7 mL or not transfused when the A-V O2diff > 3.7 mL). The primary outcome was 90-day mortality. RESULTS: Patients managed with an "appropriate" strategy had lower mortality rates (23/96 [24%] vs. 36/81 [44%]; p = 0.004), and an "appropriate" strategy was independently associated with reduced mortality (hazard ratio [HR] 0.51 [95% CI 0.30-0.89], p = 0.01). There was a trend to less acute kidney injury with the "appropriate" than with the "inappropriate" strategy (13% vs. 26%, p = 0.06), and the Sequential Organ Failure Assessment (SOFA) score decreased more rapidly (p = 0.01). The A-V O2diff, but not the ScvO2, predicted 90-day mortality in transfused (AUROC = 0.656) and non-transfused (AUROC = 0.630) patients with moderate accuracy. Using the ROC curve analysis, the best A-V O2diff cutoffs for predicting mortality were 3.6 mL in transfused and 3.5 mL in non-transfused patients. CONCLUSIONS: In anemic, non-bleeding critically ill patients, transfusion may be associated with lower 90-day mortality and morbidity in patients with higher A-V O2diff. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03767127. Retrospectively registered on 6 December 2018.

The predictive value of PaO2/FIO2 and additional parameters for in-hospital mortality in patients with acute pulmonary embolism: an 8-year prospective observational single-center cohort study.

BACKGROUND: Rapid stratification and appropriate treatment on admission are critical to saving lives of patients with acute pulmonary embolism (PE). None of the clinical prediction tools perform well when applied to all patients with acute PE. It may be important to integrate respiratory features into the 2014 European Society of Cardiology model. First, we aimed to assess the relationship between the arterial partial pressure of oxygen/fraction of inspired oxygen (PaO2/FIO2) ratio and in-hospital mortality, determine the optimal cutoff value of PaO2/FIO2, and determine if this value, which is quick and easy to obtain on admission, is a predictor of in-hospital mortality in this population. Second, we aimed to evaluate the potential additional determinants including laboratory parameters that may affect the in-hospital mortality. We hypothesized that the PaO2/FiO2 ratio would be a clinical prediction tool for in-hospital mortality in patients with acute PE. METHODS: A prospective single-center observational cohort study was conducted in Beijing Hospital from January 2010 to November 2017. Arterial blood gas analysis data captured on admission, clinical characteristics, risk factors, laboratory data, imaging findings, and in-hospital mortality were compared between survivors and non-survivors. The area under the receiver operating characteristic curve (AUC) for in-hospital mortality based on the PaO2/FiO2 value was determined, and the association between the parameters and in-hospital mortality was analyzed by using logistic regression analysis. RESULTS: Body mass index, history of cancer, PaO2/FiO2 value, pulse rate, cardiac troponin I level, lactate dehydrogenase level, white blood cell count, D-dimer level, and risk stratification measurements differed between survivors and non-survivors. The optimal cutoff value of PaO2/FiO2 for predicting mortality was 265 (AUC = 0.765, P < 0.001). Only a PaO2/FiO2 ratio < 265 (95% confidence interval [CI] 1.823-21.483, P = 0.004), history of cancer (95% CI 1.161-15.927, P = 0.029), and risk stratification (95% CI 1.047-16.957, P = 0.043) continued to be associated with an increased risk of in-hospital mortality of acute PE. CONCLUSION: A simple determination of the PaO2/FiO2 ratio at <265 may provide important information on admission about patients' in-hospital prognosis, and PaO2/FiO2 ratio < 265, history of cancer, and risk stratification are predictors of in-hospital mortality of acute PE.

Positive End-expiratory Pressure Alone Minimizes Atelectasis Formation in Nonabdominal Surgery: A Randomized Controlled Trial.

BACKGROUND: Various methods for protective ventilation are increasingly being recommended for patients undergoing general anesthesia. However, the importance of each individual component is still unclear. In particular, the perioperative use of positive end-expiratory pressure (PEEP) remains controversial. The authors tested the hypothesis that PEEP alone would be sufficient to limit atelectasis formation during nonabdominal surgery. METHODS: This was a randomized controlled evaluator-blinded study. Twenty-four healthy patients undergoing general anesthesia were randomized to receive either mechanical ventilation with PEEP 7 or 9 cm H2O depending on body mass index (n = 12) or zero PEEP (n = 12). No recruitment maneuvers were used. The primary outcome was atelectasis area as studied by computed tomography in a transverse scan near the diaphragm, at the end of surgery, before emergence. Oxygenation was evaluated by measuring blood gases and calculating the ratio of arterial oxygen partial pressure to inspired oxygen fraction (PaO2/FIO2 ratio). RESULTS: At the end of surgery, the median (range) atelectasis area, expressed as percentage of the total lung area, was 1.8 (0.3 to 9.9) in the PEEP group and 4.6 (1.0 to 10.2) in the zero PEEP group. The difference in medians was 2.8% (95% CI, 1.7 to 5.7%; P = 0.002). Oxygenation and carbon dioxide elimination were maintained in the PEEP group, but both deteriorated in the zero PEEP group. CONCLUSIONS: During nonabdominal surgery, adequate PEEP is sufficient to minimize atelectasis in healthy lungs and thereby maintain oxygenation. Thus, routine recruitment maneuvers seem unnecessary, and the authors suggest that they should only be utilized when clearly indicated. VISUAL ABSTRACT: An online visual overview is available for this article at http://links.lww.com/ALN/B728.

Impact of Low Tidal Volumes During One-Lung Ventilation. A Meta-Analysis of Randomized Controlled Trials.

OBJECTIVES: The link between ventilation strategies and perioperative outcomes remains one of the fundamental paradigms of thoracic anaesthesia. During one-lung ventilation (OLV), one lung is excluded from gas exchange and ventilation is directed at the dependent lung. The authors hypothesised that the use of low tidal volumes (VT) during OLV provides adequate gas exchange and improves postoperative outcome. DESIGN: Meta-analysis of randomized clinical trials. SETTING: Thoracic surgery. PARTICIPANTS: Patients undergoing OLV. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The authors performed a meta-analysis of all randomized trials on low versus high VT during OLV in patients undergoing thoracic surgery. Outcomes of the study were gas exchange and airway pressures during and after OLV, postoperative pulmonary complications (PPCs), and hospital stay (HLOS). Fourteen randomized trials were selected, but only a few of them contained one outcome of interest. Low VT was associated with lower arterial oxygen tension, lower airway pressures, and higher arterial carbon dioxide tension at specific time points during OLV. Low VT was associated with preserved gas exchange after OLV, lower incidence of pulmonary infiltrations, and acute respiratory distress syndrome. Incidences of PPCs and HLOS were similar. CONCLUSIONS: The use of low VT reduces airway pressure but worsens gas exchange during OLV. Preservation of postoperative oxygenation and reduction in infiltrates suggest a lung-protective modality with no demonstrable impact on PPCs and HLOS.

Near-Infrared Spectroscopy Hemoglobin Index Measurement During Fluid Challenge: A Prospective Study in Cardiac Surgery Patients.

OBJECTIVE: Little is known about changes in near-infrared spectroscopy-derived tissue hemoglobin index (HbI). The authors tested the hypothesis that absolute values and changes in brain hemoglobin index (HbIb) and skeletal muscle hemoglobin index (HbIm) could differ from the reference arterial hemoglobin (Hb) during fluid challenge. DESIGN: A prospective, monocenter observational study. SETTING: A 16-bed cardiac surgical intensive care unit in a teaching university hospital. PARTICIPANTS: Fifty consecutive adult patients. INTERVENTIONS: Investigation before and after a fluid challenge. MEASUREMENTS AND MAIN RESULTS: Simultaneous comparative Hb, HbIb and HbIm data points were collected from a blood-gas analyzer and the EQUANOX device (Nonin Medical Inc., Plymouth, MN). Correlations were determined by linear regression. No significant relationship was found between absolute values of Hb and HbIb before (R(2)= 0.04, p = 0.627) and after (R(2) = 0.00006, p = 0.956) fluid challenge. No significant relationship was found between absolute values of Hb and HbIm before (R(2)= 0.030, p = 0.226) and after (R(2) = 0.05, p = 0.117) the fluid challenge. No significant relationship was found between changes in Hb and HbIb (R(2)= 0.26, p = 0.263) and between changes in Hb and HbIm (R(2) = 0.001, p = 0.801) after the fluid challenge. Bland-Altman analysis showed a poor concordance between changes in Hb and HbIb, and changes in Hb and HbIm, with large limits of agreement. CONCLUSIONS: HbIb and HbIm cannot be used to provide continuous noninvasive estimation of Hb, and trends in HbIb and HbIm cannot be considered as noninvasive surrogates for the trend in Hb after cardiac surgery.

Evaluation of the PaO2/FiO2 ratio after cardiac surgery as a predictor of outcome during hospital stay.

BACKGROUND: The arterial partial pressure of O2 and the fraction of inspired oxygen (PaO2/FiO2) ratio is widely used in ICUs as an indicator of oxygenation status. Although cardiac surgery and ICU scores can predict mortality, during the first hours after cardiac surgery few instruments are available to assess outcome. The aim of this study was to evaluate the usefulness of PaO2/FIO2 ratio to predict mortality in patients immediately after cardiac surgery. METHODS: We prospectively studied 2725 consecutive cardiac surgery patients between 2004 and 2009. PaO2/FiO2 ratio was measured on admission and at 3 h, 6 h, 12 h and 24 h after ICU admission, together with clinical data and outcomes. RESULTS: All PaO2/FIO2 ratio measurements differed between survivors and non-survivors (p < 0.001). The PaO2/FIO2 at 3 h after ICU admission was the best predictor of mortality based on area under the curve (p < 0.001) and the optimum threshold estimation gave an optimal cut-off of 222 (95% Confidence interval (CI): 202-242), yielding three groups of patients: Group 1, with PaO2/FIO2 > 242; Group 2, with PaO2/FIO2 from 202 to 242; and Group 3, with PaO2/FIO2 < 202. Group 3 showed higher in-ICU mortality and ICU length of stay and Groups 2 and 3 also showed higher respiratory complication rates. The presence of a PaO2/FIO2 ratio < 202 at 3 h after admission was shown to be a predictor of in-ICU mortality (OR:1.364; 95% CI:1.212-1.625, p < 0.001) and of worse long-term survival (88.8% vs. 95.8%; Log rank p = 0.002. Adjusted Hazard ratio: 1.48; 95% CI:1.293-1.786; p = 0.004). CONCLUSIONS: A simple determination of PaO2/FIO2 at 3 h after ICU admission may be useful to identify patients at risk immediately after cardiac surgery.

Physiological predictors of survival during high-frequency oscillatory ventilation in adults with acute respiratory distress syndrome.

INTRODUCTION: Data that provide clinical criteria for the identification of patients likely to respond to high-frequency oscillatory ventilation (HFOV) are scarce. Our aim was to describe physiological predictors of survival during HFOV in adults with severe acute respiratory distress syndrome (ARDS) admitted to a respiratory failure center in the United Kingdom. METHODS: Electronic records of 102 adults treated with HFOV were reviewed retrospectively. We used logistic regression and receiving-operator characteristics curve to test associations with oxygenation and mortality. RESULTS: Patients had severe ARDS with a mean (SD) Murray's score of 2.98 (0.7). Partial pressure of oxygen in arterial blood to fraction of inspired oxygen (PaO2/FiO2) ratio and oxygenation index improved only in survivors. The earliest time point at which the two groups differed was at three hours after commencing HFOV. An improvement of >38% in PaO2/FiO2 occurring at any time within the first 72 hours, was the best predictor of survival at 30 days (area under the curve (AUC) of 0.83, sensitivity 93%, specificity 78% and a positive likelihood ratio (LR) of 4.3). These patients also had a 3.5 fold greater reduction in partial pressure of carbon dioxide in arterial blood (PaCO2). Multivariate analysis showed that HFOV was more effective in younger patients, when instituted early, and in patients with milder respiratory acidosis. CONCLUSIONS: HFOV is effective in improving oxygenation in adults with ARDS, particularly when instituted early. Changes in PaO2/FiO2 during the first three hours of HFOV can identify those patients more likely to survive.

Hyperoxemia and long-term outcome after traumatic brain injury.

INTRODUCTION: The relationship between hyperoxemia and outcome in patients with traumatic brain injury (TBI) is controversial. We sought to investigate the independent relationship between hyperoxemia and long-term mortality in patients with moderate-to-severe traumatic brain injury. METHODS: The Finnish Intensive Care Consortium database was screened for mechanically ventilated patients with a moderate-to-severe TBI. Patients were categorized, according to the highest measured alveolar-arterial O2 gradient or the lowest measured PaO2 value during the first 24 hours of ICU admission, to hypoxemia (<10.0 kPa), normoxemia (10.0 to 13.3 kPa) and hyperoxemia (>13.3 kPa). We adjusted for markers of illness severity to evaluate the independent relationship between hyperoxemia and 6-month mortality. RESULTS: A total of 1,116 patients were included in the study, of which 16% (n = 174) were hypoxemic, 51% (n = 567) normoxemic and 33% (n = 375) hyperoxemic. The total 6-month mortality was 39% (n = 435). A significant association between hyperoxemia and a decreased risk of mortality was found in univariate analysis (P = 0.012). However, after adjusting for markers of illness severity in a multivariate logistic regression model hyperoxemia showed no independent relationship with 6-month mortality (hyperoxemia vs. normoxemia OR 0.88, 95% CI 0. 63 to 1.22, P = 0.43; hyperoxemia vs. hypoxemia OR 0.97, 95% CI 0.63 to 1.50, P = 0.90). CONCLUSION: Hyperoxemia in the first 24 hours of ICU admission after a moderate-to-severe TBI is not predictive of 6-month mortality.

Clinical application of lung ultrasound score on COVID-19 setting: a regional experience in Southern Italy.

OBJECTIVE: We aimed to assess the correlation between LUS Soldati proposed score and clinical presentation, course of disease and the possible need of ventilation support/intensive care. PATIENTS AND METHODS: All consecutive patients with laboratory confirmed SARS-CoV-2 infection and hospitalized in two COVID Centers were enrolled. All patients performed blood gas analysis and lung ultrasound (LUS) at admission. The LUS acquisition was based on standard sequence of 14 peculiar anatomic landmarks with a score between 0-3 based on impairment of LUS picture. Total score was computed with their sum with a total score ranging 0 to 42, according to Soldati LUS score. We evaluated the course of hospitalization until either discharge or death, the ventilatory support and the transition in intensive care if needed. RESULTS: One hundred and fifty-six patients were included in the final analysis. Most of patients presented moderate-to-severe respiratory failure (FiO2 <20%, PaO2 <60 mmHg) and consequent recommendation to invasive mechanic ventilation (CPAP/NIV/OTI). The median ultrasound thoracic score was 28 (IQR 18-36) and most of patients could be ascertained either in a score 2 (40%) or score 3 pictures (24.4%). The bivariate correlation analysis displayed statistically significant and high positive correlations between the LUS score and the following parameters: ventilation (rho=0.481, p<0.001), lactates (rho=0.464, p<0.001), dyspnea (rho=0.398, p=0.001) mortality (rho=0.410, p=0.001). Conversely, P/F (rho= -0.663, p<0.001), pH (rho = -0.363, p=0.003) and pO2 (rho = -0.400 p=0.001) displayed significant negative correlations. CONCLUSIONS: LUS score improve the workflow and provide an optimal management both in early diagnosis and prognosis of COVID-19 related lung pathology.

Biochemistry tests in hospitalized COVID-19 patients: Experience from a Canadian tertiary care centre.

BACKGROUND: Coronavirus Disease 2019 (COVID-19) has variable clinical presentation, from asymptomatic to severe disease leading to death. Biochemical markers may help with management and prognostication of COVID-19 patients; however, their utility is still under investigation. METHODS: A retrospective study was conducted to evaluate alanine aminotransferase, C-reactive protein (CRP), ferritin, lactate, and high sensitivity troponin T (TnT) levels in 67 patients who were admitted to a Canadian tertiary care centre for management of COVID-19. Logistic, cause-specific Cox proportional-hazards, and accelerated failure time regression modelling were performed to assess the associations of initial analyte concentrations with in-hospital death and length of stay in hospital; joint modelling was performed to assess the associations of the concentrations over the course of the hospital stay with in-hospital death. RESULTS: Initial TnT and CRP concentrations were associated with length of stay in hospital. Eighteen patients died (27%), and the median initial TnT concentration was higher in patients who died (55 ng/L) than those who lived (16 ng/L; P < 0.0001). There were no survivors with an initial TnT concentration > 64 ng/L. While the initial TnT concentration was predictive of death, later measurements were not. Only CRP had prognostic value with both the initial and subsequent measurements: a 20% increase in the initial CRP concentration was associated with a 14% (95% confidence interval (CI): 1-29%) increase in the odds of death, and the hazard of death increased 14% (95% CI: 5-25%) for each 20% increase in the current CRP value. While the initial lactate concentration was not predictive of death, subsequent measurements were. CONCLUSION: CRP, lactate and TnT were associated with poorer outcomes and appear to be useful biochemical markers for monitoring COVID-19 patients.

The effect of adenotonsillectomy on ventilatory control in children with obstructive sleep apnea.

STUDY OBJECTIVES: The contribution of ventilatory control to the pathogenesis of obstructive sleep apnea (OSA) in children and the effect of adenotonsillectomy are unknown. We aimed to examine the difference in ventilatory control between children with OSA and those without OSA. We also examined the effect of adenotonsillectomy on parameters of ventilatory control. METHODS: Healthy children with OSA and matched controls were recruited. Polysomnography was performed before adenotonsillectomy in the OSA group and 6 months postoperatively. Controls underwent the same assessment at the two time points. Loop gain (LG), controller gain (CG), and plant gain (PG), which reflect the stability of ventilatory control, chemoreceptor sensitivity and the pulmonary control of blood gas in response to a change in ventilation, respectively, were estimated from polysomnographic tracings which included spontaneous sighs and tracings with tidal breathing. A linear mixed model was used to examine the changes of the ventilatory control parameters from baseline to 6 months. RESULTS: Ninety-nine children aged 7-13 were recruited to the study. Fifty-three with OSA and 46 controls. At baseline, compared with controls, children with OSA had higher PG and lower CG. LG did not differ between groups. Six months following adenotonsillectomy, there was a significant decrease in PG in the OSA group, while no change observed in the control group. CONCLUSIONS: The study demonstrates that the pulmonary control of blood gas homeostasis is disturbed in children with OSA and it normalizes following adenotonsillectomy.

Novel portable device measures preoperative patient metabolic gas exchange.

BACKGROUND: Indirect calorimetry (IC), the measurement of airway CO2 elimination (VCO2), O2 [corrected] uptake (VO2) [corrected], and respiratory exchange ratio (RER = VCO2/VO2), is a noninvasive modality for the assessment of body metabolism. In anesthesia, IC can signal critical events and onset of acute metabolic derangements. We have previously demonstrated the accuracy and precision of a new IC measurement system designed for mechanically ventilated patients, comprised of a new clinical bymixer, fast response humidity and temperature sensor, and a flowmeter. However, measurement of IC during spontaneous breathing is challenging because of unstable tidal volume, frequency, and functional residual capacity (FRC). METHODS: A new device for IC measurements, designed specifically for spontaneous breathing, was validated against a metabolic lung simulator bench setup. In a second study, the same device was used to conduct preoperative measurements of VCO2 and VO2 in 15 patients. RESULTS: Our measurements showed excellent correlation and agreement with metabolic lung simulator values: The average (+/-SD) percent error for airway VCO2 was -4.7% +/- 3.31%; the average (+/-SD) percent error for airway VO2 was -0.30% +/- 5.25%. Average values of VCO2 and VO2 in the patient study (3.01 +/- 0.56 and 3.44 +/- 0.69 mL x kg(-1) x min(-1), respectively) were in agreement with previously reported values. CONCLUSION: We have shown that the new, portable bymixer-flow device, using a bymixer and a fast response humidity sensor, provided accurate and convenient bedside measurement of VCO2 and VO2. We believe that it can contribute in the future to preoperative assessment and baseline reference value for perioperative management.

Continuous monitoring of central venous oxygen saturation (Pediasat) in pediatric patients undergoing cardiac surgery: a validation study of a new technology.

OBJECTIVE: Mixed venous oxygen saturation and central venous oxygen saturation are considered possible indicators of the adequacy of oxygen delivery with respect to the oxygen needs of critically ill adult and pediatric patients. The present study was aimed at validating the accuracy of a new technology (Pediasat central venous catheter) in providing a continuous measurement of the central venous oxygen saturation in pediatric patients. DESIGN: A prospective observational study. PARTICIPANTS: Thirty pediatric patients (age, 6 days-9 years) undergoing cardiac operations. Data obtained with the Pediasat during and after the operation were compared with simultaneously collected venous blood samples analyzed with standard laboratory techniques. SETTING: A clinical research hospital. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: A Bland and Altman analysis was performed on 30 matched sets of data collected before cardiopulmonary bypass, during cardiopulmonary bypass, and during the intensive care unit stay. Before cardiopulmonary bypass, there was a bias of 0.003, with lower and upper limits of agreement, -5.84 and 5.84 (percentage error, 17.3%). During cardiopulmonary bypass, the bias was 0.57 and lower and upper limits of agreement were -7.7 and 8.7 (percentage error, 23.2%). At 2 hours after the arrival in the intensive care unit, the bias was -0.6 and the lower and upper limits of agreement were -8 and 6.8 (percentage error, 20.3%). CONCLUSIONS: Because of the minimal bias and the acceptable value of percentage error, the Pediasat may be considered as an accurate tool for the continuous measurement of the central venous oxygen saturation in neonates and pediatric patients during and after cardiac operations.

Arterial blood gas derangement and level of comorbidity are not predictors of long-term mortality of COPD patients treated with mechanical ventilation.

BACKGROUND AND OBJECTIVE: Limited and inconsistent data exist on simple, readily available predictors of long-term mortality of critically ill chronic obstructive pulmonary disease patients requiring invasive mechanical ventilation. We therefore examined the influence of arterial blood gas derangement and burden of comorbidities on 90-day and 1-yr mortality of chronic obstructive pulmonary disease patients treated with invasive mechanical ventilation. METHODS: We identified all chronic obstructive pulmonary disease patients (n = 230) treated with invasive mechanical ventilation between 1994 and 2004 at a Danish primary-level hospital. Data on arterial blood gas specimens and comorbidity were obtained from medical records and Hospital Discharge Registries. We used Cox's regression analysis to estimate mortality ratios according to arterial blood gas values and level of comorbidity. RESULTS: Ninety-day and 1-yr mortality among chronic obstructive pulmonary disease patients requiring invasive mechanical ventilation was 30.8% and 40.5%, respectively. All 90-day and 1-yr mortality ratios according to arterial blood gas values were close to one and one was included in all 95% CI. Among patients with a high level of comorbidity 90-day mortality ratio was 1.3 (95% CI: 0.6-2.7) when compared with patients without comorbidity. The corresponding 1-yr mortality ratio was 1.4 (95% CI: 0.7-2.9). CONCLUSION: Chronic obstructive pulmonary disease patients treated with invasive mechanical ventilation have substantial long-term mortality. Neither the levels of arterial blood gas values measured immediately before invasive mechanical ventilation was initiated nor the burden of comorbidity were strong determinants of long-term mortality among these patients.

Anti-parietal cell autoimmunity is associated with an accelerated decline of lung function in IPF patients.

BACKGROUND: Autoantibodies against lung epithelial antigens are often detected in patients with Idiopathic Pulmonary Fibrosis (IPF). Anti-Parietal Cell Antibodies (APCA) target the H+/K+ATPase (proton pump). APCA prevalence and lung H+/K+ATPase expression was never studied in IPF patients. METHODS: We retrospectively collected clinical, lung function and imaging data from APCA positive patients (APCA+IPF) and compared them with APCA negative IPF patients matched on the date of diagnostic assessment. H+/K+ATPase expression was assessed with immunohistochemistry and PCR. RESULTS: Among 138 IPF patients diagnosed between 2007 and 2014 and tested for APCA, 19 (13.7%) APCA+ patients were identified. APCA+IPF patients were 16 men and 3 women, mean age 71 years. The median titer of APCA was 1:160. A pernicious anemia was present in 5 patients and preceded the fibrosis in 3 cases. With a mean follow up of 31 months, 2 patients had an exacerbation and 7 patients died. As compared with 19 APCA- IPF patients, APCA+IPF patients had a less severe disease with better DLCO (57% vs 43% predicted), preserved PaO2 (85 ± 8 mmHg vs 74 ± 11 mmHg), a lower rate of honeycombing on HRCT (58% vs 89%), but they experienced an accelerated decline of FVC (difference 61.4 ml/year; p = .0002). The H+/K+ATPase was strongly expressed by hyperplastic alveolar epithelial cells in the fibrotic lung. CONCLUSION: Anti-parietal cell autoimmunity is detected in some IPF patients and is associated with an accelerated decline of lung function. Anti-parietal cell autoimmunity may promote lung fibrosis progression.

Changes in utilization of intraoperative laboratory testing associated with the introduction of point-of-care testing devices in an academic department.

BACKGROUND: Availability of point-of-care testing (POCT) technology may lead to unnecessary testing and expense without improving outcomes. We tested the hypothesis that frequency of intraoperative blood testing (IBT) would increase in association with installation of POCT devices in our surgical suites. METHODS: We performed a retrospective analysis of 38,115 electronic anesthesia records for cases performed in the 1 yr before and 1 yr after POCT installation. For each case, the frequency of IBT was tabulated and the change in frequency of IBT between the study periods was calculated for individual anesthesiologists, for the department as a whole, and for clusters of anesthetizing locations. RESULTS: For the department as a whole, there was no significant change between the before and after study periods in the 13% proportion of cases in which IBT was obtained. For cases in which IBT was used, there was no significant increase in the number of IBTs per case. CONCLUSIONS: We found no significant increase in the overall utilization of IBT associated with POCT presence in noncardiothoracic operating rooms.

Cardiovascular bubble dynamics.

Gas bubbles can form in the cardiovascular system as a result of patho-physiological conditions or can be intentionally introduced for diagnostic or therapeutic reasons. The dynamic behavior of these bubbles is caused by a variety of mechanisms, such as inertia, pressure, interfacial tension, viscosity, and gravity. We review recent advances in the fundamental mechanics and applications of cardiovascular bubbles, including air embolism, ultrasound contrast agents, targeted microbubbles for drug delivery and molecular imaging, cavitation-induced tissue erosion for ultrasonic surgery, microbubble-induced angiogenesis and arteriogenesis, and gas embolotherapy.

The influence of high volume hemofiltration on extra vascular lung water and alveolar-arterial oxygen pressure difference in patients with severe sepsis.

OBJECTIVE: To explore the effects of high-volume hemofiltration (HVHF) on the plasma interleukin-6 (IL-6), pro-calcitonin (PCT), extra vascular lung water index (EVLWI) and alveolar-arterial oxygen exchange in patients with septic shock. PATIENTS AND METHODS: 97 cases intensive patients with septic shock were enrolled  from Department of Intensive Care Unit (ICU) of the Provincial Hospital affiliated to Shandong University between January 2011 and December 2014. According to the puting into practice of high-volume hemofiltration (HVHF) or not, all the patients were divided in two groups (NHVHF group, group A, n = 46 cases) and (HVHF group, group B, n = 51 cases). The plasma IL-6, PCT intrathoracic blood volume index (ITBVI), extra-vascular lung water index (EVLWI) and pulmonary vascular permeability index(PVPI) was detected before treatment and after treatment 24h, 72h The Alveolar- arterial oxygen pressure difference P(A-a)DO2 was checked by arterial blood gas analysis (ABGA) at first and after treatment 24 hour, 72 hour, 7 day in two groups. The mortality at 28 day was compared between two groups. RESULTS: After 72h treatment, the plasma IL-6, PCT in group B has a significant decrease. After 72h treatment, the level ITBVI, EVLWI and PVPI in group B had a significant improvement. The levels of P(A-a)DO2 in HVHF group were reduced more significantly than N-HVHF group after 7 day. The EVLWI and P(A-a)DO2 had a significant positive correlation (correlation ratio = 0.712, 95% confident interval [0.617, 0.773], p = 0.001). The mortality at 28 day had a significant decrease between groups (15.22% vs. 34.15% χ2 = 4.242, p = 0.038). CONCLUSIONS: HVHF could decrease plasma inflammatory factors and EVLWI so that it could improve the levels of alveolar-arterial-oxygen exchange in patients with septic shock, so it could improve the survival rate of patients.

Point-of-care testing in the intensive care unit. The intensive care physician's perspective.

Technological advancements have, for the first time, made the entire laboratory testing process feasible at the bedside. Physicians working in the intensive care unit have always had immediate access to patients' medical history, physical examination, and physiologic monitoring data, but had to wait for laboratory results. Using point-of-care testing, laboratory parameters targeted to critical illnesses can now be integrated into initial diagnostic assessments, on patient rounds, and during therapeutic maneuvers. The concept of point-of-care testing in the intensive care unit is relatively new, but as technology progresses, physicians will undoubtedly become aware and use it in the intensive care unit. This article focuses on the intensive care physician's perspective on laboratory testing, the evolution of the intensive care unit laboratory, advantages of point-of-care testing in that setting, new developments in arterial blood gas analyzers and monitors, and cost-effectiveness and incorporation of point-of-care testing.