Objective: To investigate the correlation between heart rate index (HRI), systolic blood pressure(SBP) peak-to-SBPrest ratio (SBPR) and peak oxygen consumption (peakVO₂) in patients with chronic heart failure (CHF), and discuss the possibility of using HRI and SBPR collected during exercise to assess the exercise tolerance of CHF patients in the absence of gas analysis. Methods: In this cross-sectional study, a total of 547 patients with CHF who underwent cardiopulmonary exercise test(CPET) in Tongji Hospital Heart Rehabilitation Center Affiliated to Tongji University from March 2007 to December 2018 were collected retrospectively, focusing on their clinical data including age, gender, type of heart failure,BMI as well as data collected during their CPETs, such as peakVO₂, HRI and SBPR. Spearman univariate correlation analysis was used for statistical analysis, to unveil the correlations between peakVO₂ and those parameters, and multiple linear regression analysis was also conducted. Results: A total of 547 CHF patients conducting CPET were included in this research, of which 447 were male, at age of 63(56, 69). Univariate analysis indicates that HRI, SBPR and peakVO₂ showed significant positive correlation (r=0.323, 0.263, respectively, all P<0.001); Age and peak VO₂ showed significant negative correlation(r=-0.207, P<0.001); Male patients showed peakVO₂ higher than female(r=-0.229, P<0.001); PeakVO₂ of heart failure with reduced ejection fraction(HFrEF) was lower than heart failure with mid-range ejection fraction(HFmrEF)and heart failure with preserved ejection fraction(HFpEF) (r=0.181, P<0.001). Body mass index (BMI) had no significant correlation with peakVO₂ (P>0.05). Multivariate linear regression analysis showed that the HRI, SBPR were positively correlated with peakVO₂(t=7.68, 5.08, respectively, all P<0.05), while age and BMI showed negative correlation with peakVO₂(t=-5.43, -0.31, respectively, all P<0.05). PeakVO₂ of male was higher than female(t=-6.03, P<0.05), and peakVO₂ of HFrEF was lower than those of HFmrEF and HFpEF(t=3.17, 4.48, respectively, all P<0.05). A linear equation (F=33.52, adjusted R²=0.29) could be constructed: peakVO₂=10.65(male) or 8.53(female)+4.26HRI+3.31SBPR-0.07age-0.13BMI+0(HFrEF) or 1.05 (HFmrEF) or 1.62(HFpEF). Conclusion: HRI and SBPR are positively correlated with peakVO₂. In the absence of gas analysis, it is possible to apply HRI and SBPR during exercise to predict exercise tolerance in patients with CHF.
Chronic Disease ; Cross-Sectional Studies ; Female ; Heart Failure ; Heart Rate ; Humans ; Male ; Oxygen Consumption/physiology* ; Prognosis ; Retrospective Studies ; Stroke Volume/physiology*

OBJECTIVE: To explore aerobic power and energy expenditure of high level rugby players in China, which provide experimental basis for accurate training and nutritional strategy in match-play. METHODS: Eighteen master rugby players were selected as research subjects. The parameters such as VOmax, lactic aicd threshold (LT) and modify conconi test were measured respectively. The differences of energy were compared between the forward and the defender. The data were analyzed by independent sample t test. RESULTS: The VOmax(42.05±3.69 ml/min ·kg) of rugby players was poorer. The VOmax of the forward was 38.83±3.52 (ml/min ·kg), and that of the defender was 47.31±3.17 (ml/min ·kg),and there was significant difference between the forwards and the defenders (P＜0.05). The LT of the defenders was obviously higher than that of the forwards. Modifier conconi test had a high correlation (r = 0.772) with VOmax. The average energy consumption in the first half of the game was about(276.94±18.08)kcals, the second half was(225.58±22.86)kcals, and the second half was less than the first half (P＜0.05). CONCLUSION The aerobic power is different between the forwards and the defenders. The power of aerobic of Chinese players is weaker than that of the foreign rugby players.
Asian Continental Ancestry Group ; Athletes ; China ; Energy Metabolism ; Football ; physiology ; Humans ; Oxygen Consumption

Animals ; Humans ; Oxidative Stress ; Oxygen Consumption ; physiology ; Plants ; metabolism ; Reactive Oxygen Species ; metabolism

The present study was to examine the effect of stellate ganglion block (SGB) on bilateral regional cerebral oxygen saturation (rSO2) and postoperative cognitive function. Eighty patients undergoing selective coronary artery bypass graft with cardiopulmonary bypass (CPB) were randomly and equally divided into two groups. The patients in group S were given right SGB with ropivacaine, while the patients in group C were injected with normal saline. We compared the bilateral rSO2 after SGB. Minimum Mental State Examination (MMSE), Visual Verbal Learning Test (VVLT), and Digital Span Test (DST) were applied to observe the effect on cognitive function. We found that the incidence of postoperative cognitive dysfunction (POCD) 7 days after surgery in group S was lower than that in group C. The level of blocked side rSO₂ of S group were significantly higher before CPB time of rewarming than that before SGB (P < 0.05), much higher than corresponding non-blocked side rSO₂ before CPB (P < 0.05), and much higher than rSO₂ level in group C before CPB and after CPB (P < 0.05). The non-blocked side rSO₂ in group S before anesthesia were much lower than basic levels and those in group C (P < 0.05). It could be concluded from the above results that there was significant increase in the blocked-side rSO₂ compared to the non-blocked side and there was significant decrease in the incidence of POCD compared to the control group after SGB.
Autonomic Nerve Block ; adverse effects ; Cardiopulmonary Bypass ; adverse effects ; Cerebrum ; physiology ; Cognition ; Cognition Disorders ; Coronary Artery Bypass ; adverse effects ; Humans ; Incidence ; Oxygen ; physiology ; Oxygen Consumption ; Postoperative Complications ; Stellate Ganglion

Energy Metabolism ; Humans ; Oxygen Consumption ; Walking ; physiology ; Weight-Bearing ; physiology

BACKGROUNDAfter cardiac surgery, central venous oxygen saturation (ScvO 2 ) and serum lactate concentration are often used to guide resuscitation; however, neither are completely reliable indicators of global tissue hypoxia. This observational study aimed to establish whether the ratio between the veno-arterial carbon dioxide and the arterial-venous oxygen differences (P(v-a)CO 2 /C(a-v)O 2 ) could predict whether patients would respond to resuscitation by increasing oxygen delivery (DO 2 ).

METHODSWe selected 72 patients from a cohort of 290 who had undergone cardiac surgery in our institution between January 2012 and August 2014. The selected patients were managed postoperatively on the Intensive Care Unit, had a normal ScvO 2 , elevated serum lactate concentration, and responded to resuscitation by increasing DO 2 by >10%. As a consequence, 48 patients responded with an increase in oxygen consumption (VO 2 ) while VO 2 was static or fell in 24.

RESULTSAt baseline and before resuscitative intervention in postoperative cardiac surgery patients, a P(v-a)CO 2 /C(a-v)O 2 ratio ≥1.6 mmHg/ml predicted a positive VO 2 response to an increase in DO 2 of >10% with a sensitivity of 68.8% and a specificity of 87.5%.

CONCLUSIONSP(v-a)CO 2 /C(a-v)O 2 ratio appears to be a reliable marker of global anaerobic metabolism and predicts response to DO 2 challenge. Thus, patients likely to benefit from resuscitation can be identified promptly, the P(v-a)CO 2 /C(a-v)O 2 ratio may, therefore, be a useful resuscitation target.

Adult ; Aged ; Blood Gas Analysis ; Carbon Dioxide ; blood ; Cardiac Surgical Procedures ; Female ; Humans ; Hyperlactatemia ; blood ; therapy ; Intensive Care Units ; statistics & numerical data ; Lactic Acid ; blood ; Male ; Middle Aged ; Oxygen Consumption ; physiology ; Prospective Studies ; Resuscitation

PURPOSE: This study was conducted to compare effects of open and closed suctioning methods on lung dynamics (dynamic compliance, tidal volume, and airway resistance) and hypoxemia (oxygen saturation and heart rate) in mechanically ventilated patients. METHODS: This study was a cross-over repeated design. Participants were 21 adult patients being treated with endotracheal intubation using a pressure-controlled ventilator below Fraction of Inspired Oxygen (FiO2) 60% and PEEP 8 cmH2O. Data were collected at baseline and 1, 2, 3, 4, 5, and 10 minutes after suctioning. Data were analyzed using two-factor ANOVA with repeated measures on time and suctioning type. RESULTS: Effects of the interaction between suction type and time were significant for oxygen saturation and heart rate but not significant for dynamic compliance, tidal volume, or airway resistance. Prior to performance of suctioning, tidal volume and oxygen saturation were significantly lower, but airway pressure and heart rate were significantly higher using the closed suctioning method as compared with the open suctioning method. CONCLUSION: For patients on ventilator therapy below FiO2 60% and PEEP 8cmH2O, open suctioning performed after delivery of 100% FiO2 using a mechanical ventilator may not have as much negative impact on lung dynamics and hypoxemia as closed suctioning.
APACHE ; Adult ; Aged ; Aged, 80 and over ; Anoxia/*physiopathology/therapy ; Female ; Heart Rate/physiology ; Humans ; Intubation, Intratracheal ; Lung/*physiopathology ; Male ; Middle Aged ; Oxygen Consumption/physiology ; Respiration, Artificial/*instrumentation ; Suction

PURPOSE: We performed a study to determine the best appropriate wearing site of a triaxial accelerometer at different exercise speeds. MATERIALS AND METHODS: We conducted an observational study with 66 healthy Korean adults (26 men and 40 women). Resting metabolic rate (RMR) before exercise, physical activity-related energy expenditure (PAEE) by cardiorespiratory gas analyzer and Signal Vector Magnitude (SVM) were measured while wearing four triaxial accelerometers on four different sites (wrist, waist, upper arm, and ankle) at exercise speeds from 2-10 km/h. RESULTS: The mean RMR was 4.03 mL/kg/min and Actual METs (oxygen consumption at different exercise speeds divided by individual RMR) compared with the calculated METs (oxygen consumption divided by 3.5 mL/kg/min) showed relatively low value. The overall correlation between PAEE and SVM was highest when the accelerometer was worn on the wrist at low exercise speed (r=0.751, p<0.001), waist at a moderate speed (r=0.821, p<0.001), and ankle at a high speed (r=0.559, p<0.001). Using regression analysis, it was shown that the ankle at a low speed (R2=0.564, p<0.001), high speed (R2=0.559, p<0.001), and the waist at a moderate speed (R2=0.821, p<0.001) were the best appropriate sites. CONCLUSION: When measuring the PAEE and SVM at different exercise speeds, the ankle in low and high exercise speed, and waist in moderate speed are the most appropriate sites for an accelerometer.
Adult ; Anthropometry/*methods ; Basal Metabolism/physiology ; Energy Metabolism/*physiology ; Exercise/*physiology ; Female ; Humans ; Male ; Middle Aged ; Oxygen Consumption/physiology ; Young Adult

PURPOSE: Peak oxygen uptake (peak VO2) and ventilatory inefficiency (VE/VCO2 slope) have proven to be strong prognostic markers in patients with chronic heart failure (CHF). Recently increased red cell distribution width (RDW) has emerged as an additional predictor of poor outcome in CHF. We sought to evaluate the relationship between RDW and cardiopulmonary exercise test (CPET) parameters in CHF patients and healthy controls. MATERIALS AND METHODS: 85 ambulatory CHF patients (68 men, 54+/-10 years) and 107 healthy controls, who underwent a symptom-limited CPET on a treadmill according to the modified Bruce ramp protocol, were enrolled. CHF patients and healthy controls were divided into RDW tertile groups and laboratory, echocardiographic, and CPET results were analyzed. RESULTS: For patients with CHF, compared with patients in the lowest RDW tertile, those in the highest tertile had lower peak VO2 (22 mL/kg/min vs. 28 mL/kg/min, p<0.001) and higher VE/VCO2 slope (31 vs. 25, p=0.004). Multivariate regression analysis revealed RDW to be an independent predictor for peak VO2 (beta=-0.247, p=0.035) and VE/VCO2 slope (beta=0.366, p=0.004). The optimal cutoff value of RDW for predicting peak VO2 < or =20 mL/kg/min and VE/VCO2 slope > or =34 was 13.6% (sensitivity 53%, specificity 89%) and 13.4% (sensitivity 75%, specificity 82%), respectively. In contrast, for healthy controls, RDW was not related to both peak VO2 and VE/VCO2 slope. CONCLUSION: Higher RDW is independently related to peak VO2 and VE/VCO2 slope only in patients with CHF. RDW assessment, an inexpensive and simple method, might help predict functional capacity and ventilatory efficiency in these patients.
Adult ; Erythrocyte Indices/*physiology ; Exercise Test ; Female ; Heart Failure/*physiopathology ; Humans ; Male ; Middle Aged ; Oxygen Consumption/physiology ; Retrospective Studies

OBJECTIVETo establish a method for real-time recording the oxygen consumption of mice under normobaric hypoxia.

METHODSThe experimental apparatus was made up of animal container, filling water control system, electronic balance, hose, a computer with weight recording software, etc. The working principle was that the oxygen consumed by animal was replaced by water filling which was controlled by the pneumatic and hydraulic actuator. The water was weighted by an electronic balance and the weight signal was recorded into excel file at the same time. The accuracy and precision of the apparatus were detected by a 10 ml syringe. The oxygen consumption characteristics of 6 acute repetitive hypoxia mice and 6 normal mice were observed.

RESULTSThe P value for the paired t test was 1 and the CV value was 4%. The survival time and total oxygen consumption of acute repetitive hypoxia mice were both significantly increased compared to normal mice (P < 0.05), which were (58.8 +/- 6.8) min and (46.0 +/- 8.7) min respectively for the survival time and (85.1 +/- 8.5) ml and (73.6 +/- 5.4) ml respectively for total oxygen consumption.

CONCLUSIONThe hypoxia tolerance of the acute repetitive hypoxia mice can significantly improved by taking more oxygen in the animal cabin. The accuracy and precision of the apparatus are high and it can be used for the determination of oxygen consumption in hypoxia research.

Animals ; Hypoxia ; physiopathology ; Mice ; Monitoring, Physiologic ; instrumentation ; Oxygen Consumption ; physiology