Traditionally, adequate tidal volume is considered to be a necessary condition to support respiratory patient breathing. But the high frequency ventilation (HFV) with a small tidal volume can still support the respiratory patient breathing well. In order to further explore the mechanisms of HFV, the pendelluft ventilation between left and right lungs was proposed in this paper. And a test platform by using two fresh sheep lungs was developed for investigating the pendelluft ventilation between the left and right lungs. Furthermore, considering the viscous resistance ( ), inertance ( ) and lung compliance ( ) in the lung, a second-order lung ventilation model was designed to inspect and evaluate the pendelluft ventilation between left lung and right lungs. On referring to both results of experiments in practice and simulation in MATLAB Simulink, between the left and right lungs, the phase difference in their airflow happens during HFV at some frequencies. And the pendelluft ventilation between the left and right lungs is resulted by the phase difference, even if the total airflow entering a whole lung is 0. Under HFV, the pendelluft ventilation between left and right lungs will benefit the lungs being more adequately ventilated, and will be improve the utilization rate of oxygen in the lungs.
Animals ; High-Frequency Ventilation ; Humans ; Lung ; physiology ; Pulmonary Gas Exchange ; Respiration, Artificial ; Sheep ; Tidal Volume

OBJECTIVETo compare the effect between nebulized and intravenous administration of Shenmai Injection () on pulmonary gas exchange function of patients following tourniquet-induced lower limb ischemia-reperfusion.

METHODSThirty-eight patients scheduled for lower extremity surgery were randomized into three groups using the closed envelop method: Shenmai Injection was administered 30 min before tourniquet inflflation by nebulization [0.6 mL/kg in 10 mL normal saline (NS)] in the nebulization group or by intravenous drip (0.6 mL/kg dissolved in 250 mL of 10% glucose) in the intravenous drip group, and equal volume of NS was given intravenously in the NS group; 15 in each group. Arterial blood gases were analyzed, serum levels of malonaldehyde (MDA) and interleukine-6 (IL-6) and interleukine-8 (IL-8) were determined using the method of thiobarbituric acid reaction and enzyme-linked immuno sorbent assay respectively just before tourniquet inflflation (T0), and at 0.5 h (T1), 2 h (T2), 6 h (T3) after tourniquet deflflation.

RESULTSCompared with baselines at T0, MDA levels signifificantly increased at T2, T3 in the NS group and at T3 in the nebulization group, and IL-6 and IL-8 levels were signifificantly increased at T2, T3 in NS, the intravenous drip and the nebulization groups (P <0.05). Arterial pressure of oxygen (PaO) at T3 was decreased, while alveolararterial oxygen tension showed difference (PA-aDO) at T3 in the NS group; RI at T3 in both intravenous drip and the nebulization groups were enhanced (P <0.05). Compared with the NS group, MDA and IL-8 levels at T2, T3, IL-6 at T3 in the intravenous drip group, and IL-8 at T3 in the nebulization group were all remarkably increased (P <0.05). Additionally, MDA level at T3 in the nebulization group was higher than that in the intravenous drip group (P <0.05).

CONCLUSIONSIntravenous administration of Shenmai Injection provided a better protective effect than nebulization in mitigating pulmonary gas exchange dysfunction in patients following tourniquet-induced limb ischemia-reperfusion.

Adult ; Blood Gas Analysis ; Drug Administration Routes ; Drug Combinations ; Drugs, Chinese Herbal ; administration & dosage ; pharmacology ; therapeutic use ; Female ; Humans ; Injections ; Interleukin-6 ; blood ; Interleukin-8 ; blood ; Male ; Malondialdehyde ; blood ; Pulmonary Gas Exchange ; drug effects ; Reperfusion Injury ; blood ; drug therapy ; physiopathology ; Tourniquets ; adverse effects

PURPOSE: Hypoxemia during one-lung ventilation (OLV) remains a serious problem, particularly in the supine position. We investigated the effects of alveolar recruitment (AR) and positive end-expiratory pressure (PEEP) on oxygenation during OLV in the supine position. MATERIALS AND METHODS: Ninety-nine patients were randomly allocated to one of the following three groups: a control group (ventilation with a tidal volume of 8 mL/kg), a PEEP group (the same ventilatory pattern with a PEEP of 8 cm H2O), or an AR group (an AR maneuver immediately before OLV followed by a PEEP of 8 cm H2O). The tidal volume was reduced to 6 mL/kg during OLV in all groups. Blood gas analyses, respiratory variables, and hemodynamic variables were recorded 15 min into TLV (TLVbaseline), 15 and 30 min after OLV (OLV15 and OLV30), and 10 min after re-establishing TLV (TLVend). RESULTS: Ultimately, 92 patients were analyzed. In the AR group, the arterial oxygen tension was higher at TLVend, and the physiologic dead space was lower at OLV15 and TLVend than in the control group. The mean airway pressure and dynamic lung compliance were higher in the PEEP and AR groups than in the control group at OLV15, OLV30, and TLVend. No significant differences in hemodynamic variables were found among the three groups throughout the study period. CONCLUSION: Recruitment of both lungs with subsequent PEEP before OLV improved arterial oxygenation and ventilatory efficiency during video-assisted thoracic surgery requiring OLV in the supine position.
Adult ; Aged ; Anoxia ; Female ; Humans ; Lung/physiopathology ; Lung Compliance/physiology ; Male ; Middle Aged ; One-Lung Ventilation/*methods ; Oxygen/*blood ; Positive-Pressure Respiration/*methods ; Pulmonary Alveoli/*physiology ; Pulmonary Gas Exchange ; Respiratory Mechanics/*physiology ; *Supine Position ; Thoracic Surgery, Video-Assisted ; Tidal Volume

OBJECTIVESince 1987, professor Wasserman displayed cardiopulmonary exercise test starting (CPET) data as 3 rows and 3 columns 9 panels plots. Although many changes and additions, there still are some important functional parameters were not shown in 9 panels. We want to display more.

METHODSThe 100 Hz sampling data of symptom-limited maximal limit CPET was used to calculate breath-by-breath data after per second cutting technique, and then to calculate the average value of 10 s data for graphic display.

RESULTSIn new 9 plots, panels (1) - (7) use time for the "X" axis, oxygen uptake, carbon dioxide elimination, loaded power, heart rate, systolic blood pressure, diastolic blood pressure, heart rate pressure product, minute ventilation, respiratory exchange ratio, CO2 elimination ventilatory efficiency, oxygen uptake ventilatory efficiency, oxygen pulse, ST segment level and ST segment slope at V5 lead, tidal volume, respiratory rate, end tidal oxygen partial pressure, end tidal carbon dioxide partial pressure and oxygen saturation of 18 noninvasive parameters, and arterial oxygen partial pressure, arterial oxygen saturation, arterial partial pressure of carbon dioxide 3 blood gas parameters for the "Y" axis respectively. There are 3 vertical dashed lines represent dividing lines of the resting, warm-up, incremental power loading exercise and recovery period respectively. In addition, panels (1) and (4) have the horizontal dashed line represents the maximal oxygen uptake (red), oxygen uptake efficiency plateau (red) and the lowest value of carbon dioxide elimation ventilatory efficiency (blue) expected value respectively. Panel ( used heart rate and carbon dioxide elimination (as Y) against to oxygen uptake (as X); the "+" indicates intersection of the predicted maximum values of oxygen uptake and heart rate. Panel (9) used tidal volume (as Y) against over minute ventilation (as X), vertical dashed line is the measured maximum ventilatory volume, the horizontal dashed lines were the inspiratory capacity and vital capacity respectively.

CONCLUSIONNew CPET 9 plots emphasizes on the integration of all circulatory, respiratory and metabolic etc functional parameters in human, and is conductive to optimization of clinical medical service and health management.

Arteries ; Blood Gas Analysis ; Blood Pressure ; Carbon Dioxide ; Exercise ; Exercise Test ; standards ; Heart ; Heart Rate ; Holistic Health ; Humans ; Integrative Medicine ; Oximetry ; Oxygen ; Oxygen Consumption ; Partial Pressure ; Pulmonary Gas Exchange ; Tidal Volume

A reduction in diaphragm mobility has been identified in patients with chronic obstructive pulmonary disease (COPD) and has been associated with a decline in pulmonary function parameters. However, little information exists regarding the potential role of diaphragm mobility on hypercapnia in COPD. A new method of assessing the mobility of the diaphragm, using ultrasound, has recently been validated. The purpose of the present study was to investigate the relationship between diaphragm mobility and pulmonary function parameters, as well as that between arterial blood gas values and diaphragm mobility, in COPD patients. Thirty seven COPD patients were recruited for pulmonary function test, arterial blood gas analysis and diaphragm mobility using ultrasound to measure the craniocaudal displacement of the left branch of the portal vein. There were significant negative correlations between diaphragmatic mobility and PaCO2 (r = -0.373, P = 0.030). Diaphragmatic mobility correlated with airway obstruction (FEV1, r = 0.415, P = 0.011) and with ventilatory capacity (FVC, r = 0.302, P = 0.029; MVV, r = 0.481, P = 0.003). Diaphragmatic mobility also correlated significantly with pulmonary hyperinflation. No relationship was observed between diaphragm mobility and PaO2 (r = -0.028, P = 0.873). These findings support a possibility that the reduction in diaphragm mobility relates to hypercapnia in COPD patients.
Aged ; Airway Resistance/physiology ; Carbon Dioxide/blood/physiology ; Diaphragm/physiopathology/*ultrasonography ; Female ; Humans ; Hypercapnia/complications/*physiopathology ; Male ; Middle Aged ; Portal Vein ; Pulmonary Disease, Chronic Obstructive/complications/*physiopathology/ultrasonography ; Pulmonary Gas Exchange ; Respiratory Muscles/physiopathology

OBJECTIVETo investigate the effect of Shenmai injection on vascular endothelial active facters nitric oxide (NO) and endothelin-1 (ET-1), and pulmonary gas exchange induced by tourniquet deflation in patients undergoing lower extremity surgery.

METHODTwenty-six patients scheduled for unilateral lower extremity surgery were randomly divided into 2 groups: control group (group C, n = 14) and Shenmai injection group (group SM, n = 12). All the patients agreed to a combined spinal-epidural anesthesia at the L2-L3 interspace and a radial artery catheter was placed for sampling. Patients in group SM were injected Shenmai injection 0.6 mL x kg(-1) and physiological saline 100 mL, while patients in group C were injected equal volume of normal saline instead 15 min before tourniquet inflation. Blood samples which were used for blood gas analysis and measurement of nitric oxide (NO) and endothelin-1 (ET-1) were taken before tourniquet inflation (T0, baseline) and 30 min (T1), 2 h (T2), 6 h (T3), 24 h (T4) after tourniquet deflation.

RESULTCompared with the baseline values at T0, in group C at T3 P(a) O2 and the levels of NO were significantly decreased, while P(A-a) DO2 and the levels of ET-1 at T3 were significantly increased (P < 0.05 or P < 0.01), in group SM, the levels of NO at T3 were significantly decreased (P < 0.05). Compared with group C, the changes of P(a)O2, P(A-a) DO2, NO and ET-1 were significantly mitigated in group SM.

CONCLUSIONThe concentrations of NO and ET-1 is connected with the pulmonary gas exchange impairment induced by tourniquet application. Shenmai injection can improve the pulmonary gas exchange based on rising the level of NO, reducing the level of ET-1.

Adult ; Drug Combinations ; Drugs, Chinese Herbal ; administration & dosage ; pharmacology ; Endothelin-1 ; blood ; metabolism ; Endothelium, Vascular ; drug effects ; metabolism ; physiopathology ; Female ; Humans ; Injections, Intravenous ; Male ; Middle Aged ; Nitric Oxide ; blood ; metabolism ; Pulmonary Gas Exchange ; drug effects ; Tourniquets ; adverse effects

OBJECTIVETo investigate the effects of different ventilation modes for one lung ventilation anesthesia on arterial blood-gas, airway pressure, intrapulmonary shunt, and F(A)/F(I) changes in patients receiving sevoflurane inhalation.

METHODSThirty ASA class II-III patients with lung cancer undergoing pulmonary lobectomy were randomized into 3 equal groups. The patients in group A received volume-controlled ventilation (VCV) without positive end-expiratory pressure (PEEP) (VT=8 ml/kg, Rf=12/min), and those in group B, after a preceding VCV stabilize the airway pressure, had pressure-controlled ventilation with maintenance of an identical peak pressure (Ppeak) (Rf=12/min, PEEP=0). In group C, the patients received small tidal volume ventilation with PEEP (VT=6 ml/kg, Rf=16/min, PEEP=5 cm H(2)O). Blood gas analysis was carried out at 10 min after TLV and at 20, 45 and 70 min after one lung ventilation (OLV); the heart rate (HR), mean arterial pressure (MAP), SpO(2) and Ppeak were also recorded and blood samples collected from the artery and jugular vein at these time points. Inhalation of 1.5% sevoflurane for 20 min started at 20 min of OLV.

RESULTSCompared with those in TLV, the Ppeak increased, lung compliance decreased, arterial oxygenation (PaO(2)) decreased and intrapulmonary shunt (Qs/Qt) increased during OLV. Group B showed the fastest increase of F(A)/F(I) in the initial 8 min, followed by groups A and C, but the curves became similar with the passage of time.

CONCLUSIONSDuring OLV, the 3 ventilation modes result in similar F(A)/F(I) changes during sevoflurane inhalation but PCV can increase pulmonary compliance.

Adult ; Aged ; Anesthesia ; Arterial Pressure ; Female ; Humans ; Lung Compliance ; Lung Neoplasms ; physiopathology ; Male ; Methyl Ethers ; pharmacology ; Middle Aged ; One-Lung Ventilation ; methods ; Positive-Pressure Respiration ; Pulmonary Gas Exchange ; Young Adult

BACKGROUND/AIMS: Ventilating patients with acute respiratory distress syndrome (ARDS) in the prone position has been shown to improve arterial oxygenation, but prolonged prone positioning frequently requires continuous deep sedation, which may be harmful to patients. We evaluated the meaning of early gas exchange in patients with severe ARDS under prolonged (> or = 12 hours) prone positioning. METHODS: We retrospectively studied 96 patients (mean age, 60.1 +/- 15.6 years; 75% men) with severe ARDS (PaO2/FiO2 < or = 150 mmHg) admitted to a medical intensive care unit (MICU). The terms "PaO2 response" and "PaCO2 response" represented responses that resulted in increases in the PaO2/FiO2 ratio of > or = 20 mmHg and decreases in PaCO2 of > or = 1 mmHg, respectively, 8 to 12 hours after first placement in the prone position. RESULTS: The mean duration of prone positioning was 78.5 +/- 61.2 hours, and the 28-day mortality rate after MICU admission was 56.3%. No significant difference in clinical characteristics was observed between PaO2 and PaCO2 responders and non-responders. The PaO2 responders after prone positioning showed an improved 28-day outcome, compared with non-responders by Kaplan-Meier survival estimates (p < 0.05 by the log-rank test), but the PaCO2 responders did not. CONCLUSIONS: Our results suggest that the early oxygenation improvement after prone positioning might be associated with an improved 28-day outcome and may be an indicator to maintain prolonged prone positioning in patients with severe ARDS.
Adult ; Aged ; Carbon Dioxide/blood ; Female ; Humans ; Intensive Care/methods ; Kaplan-Meiers Estimate ; Male ; Middle Aged ; Oxygen/*blood ; Positive-Pressure Respiration ; *Posture ; Pulmonary Gas Exchange ; *Respiratory Distress Syndrome, Adult/blood/mortality/therapy ; Retrospective Studies ; Severity of Illness Index ; Tidal Volume

OBJECTIVETo evaluate the effects of continuous blood purification on the hemodynamics and oxygenation in patients with acute respiratory distress syndrome (ARDS).

METHODSTwenty-one patients with ARDS were treated with continuous veno-venous hemofiltration (CVVH) combined with plasma exchange. Hemodynamics and oxygenation were measured or calculated at scheduled intervals using Swan-Ganz catheters.

RESULTSThe mean arterial pressure, partial pressure of arterial oxygen, oxygen delivery, oxygen consumption increased, heart rate, mean pulmonary arterial pressure, pulmonary capillary wedge pressure, blood lactate concentration all decreased significantly after the treatment, and the oxygen extraction ratio underwent no obvious changes.

CONCLUSIONSContinuous blood purification can increase blood and oxygen supply but has no significant effects on oxygen extraction ratio in ARDS patients.

Adult ; Female ; Hemodynamics ; Hemofiltration ; methods ; Humans ; Male ; Middle Aged ; Oxygen ; blood ; Oxygen Consumption ; physiology ; Partial Pressure ; Plasma Exchange ; methods ; Pulmonary Gas Exchange ; Respiratory Distress Syndrome, Adult ; therapy

To explore the following hypotheses: 1) Gas exchange, Organ failure, Cause, Associated disease (GOCA) score, which reflects both general health and the severity of lung injury, would be a better mortality predictor of acute respiratory distress syndrome (ARDS) than acute physiology and chronic health evaluation (APACHE II) or simplified acute physiology score (SAPS II), which are not specific to lung injury, and lung injury score (LIS) that focuses on the lung injury; 2) the performance of APACHE II and SAPS II will be improved when reinforced by LIS, we retrospectively analyzed ARDS patients (N=158) admitted to a medical intensive care unit for five years. The overall mortality of the ARDS patients was 53.2%. Calibrations for all models were good. The area under the curve of (AUC) of LIS (0.622) was significantly less than those of APACHE II (0.743) and SAPS II (0.753). The AUC of GOCA (0.703) was not better than those of APACHE II and SAPS II. The AUCs of APACHE II and SAPS II tended to further increase when reinforced by LIS. In conclusion, GOCA was not superior to APACHE II or SAPS II. The performance of the APACHE II or SAPS II tended to improve when combining a general scoring system with a scoring system that focused on the severity of lung injury.
APACHE ; Adult ; Aged ; Critical Illness/mortality ; Female ; Humans ; Intensive Care ; Male ; Middle Aged ; Predictive Value of Tests ; Prognosis ; *Pulmonary Gas Exchange ; ROC Curve ; Respiratory Distress Syndrome, Adult/*mortality/*physiopathology ; Retrospective Studies ; Risk Factors ; Sensitivity and Specificity ; *Severity of Illness Index ; Survival Analysis