Central Venous Blood Gas Analysis Research Articles

Non-invasive detection of hypovolemia or fluid responsiveness in spontaneously breathing subjects

BackgroundIn the assessment of hypovolemia the value of functional hemodynamic monitoring during spontaneous breathing is debated. The aim of our study was to investigate in spontaneously breathing subjects the changes in hemodynamic parameters during graded central hypovolemia and to test whether slow patterned breathing improved the discriminative value of stroke volume (SV), pulse pressure (PP), and their variations (SVV, PPV). In addition, we tested the alterations in labial microcirculation.Methods20 healthy volunteers participated in our study. Central hypovolemia was induced by lower body negative pressure (LBNP). Continuous signals of ECG, non-invasive blood pressure and central venous pressure were recorded. During baseline and each stage of LBNP the labial microcirculation was investigated by orthogonal polarization spectral imaging, 3 minute periods of patterned breathing at 6 and 15/min respiratory rate were performed, and central venous blood gas analysis was done. Data from baseline and those of different LBNP levels were compared by analysis of variance and those of different breathing rates by t-test. Finally, we performed ROC analysis to assess the discriminative values of SV, PP, SVV and PPV.ResultsModerate central hypovolemia induced by LBNP caused significant, clinically relevant falls in PP (p < 0.05) and SV and central venous oxygen saturation (ScvO2) (p < 0.001). The proportion of perfused vessels (p < 0.001) and microvascular flow index decreased (p < 0.05). PPV increased (p < 0.001), however the magnitude of fluctuations was greater during slow patterned breathing (p < 0.001). SVV increased only during slow patterned breathing (p < 0.001). ROC analysis confirmed the best predictive value for SV (at 56 ml cut-off AUC 0.97, sensitivity 94%, specificity 95%). Slow patterned breathing improved the discriminative value of SVV (p = 0.0023).ConclusionsFunctional hemodynamic monitoring with slow patterned breathing to control spontaneous respiration may be worthy for further study in different populations for the assessment of hypovolemia and the prediction of volume responsiveness.

The effect of two methods guided fluid therapy to the patient undergoing open gastrointestinal surgery

To investigate the effect of central venous blood oxygen saturation (ScvO2) and venous-arterial PCO2 (P(cv-a)CO2) guided fluid therapy on tissue perfusion, gastrointestinal function recovering and outcome of the patients who undergoing open gastrointestinal surgery. Forty patients undergoing open gastrointestinal surgery were randomly divided into 2 groups (n = 20 each): ScvO2 guided fluid therapy (group S) and P(cv-a) CO2 guided fluid therapy (group P). All the patients were infused 10 ml/kg lactated Ringer's (LR) solution before anesthesia induction, they were all also given a continuous lactated Ringer's (LR) solution's infusion at the speed of 2 ml·kg(-1)·h(-1) during the operation. While, 6%HES 130/0.4 (free flex 6%HES 130/0.4, Fresenius Kabi) infusion was different between the 2 groups, when the patients of group S's central venous blood oxygen saturation < 75% or venous-arterial PCO2 in the patients of P group ≥6 mm Hg, then infused 6%HES 130/0.4. Arterial and central venous blood gas analyses were performed every 20 minutes after skin incision, measure the venous and arterial lactate value, and record the anal exhaust time after surgery, postoperative complications and mortality in 28 days. Compared with group S, the arterial lactate value in T4 (after operation began 80 min) were significantly decreased in group P (P = 0.013), and venous lactate value in T5 (after operation began 100 min) were also lower (P = 0.044), other lactate value were not different (P > 0.05) . The anal exhaust time was not different between the two groups (P = 0.673). All the patients were survival, and there were no obvious postoperative complications. Compared to group S, there was a transient improvement in tissue perfusion in group P, but there were no difference in complications and mortality.

AARC Clinical Practice Guideline: Blood Gas Analysis and Hemoximetry: 2013

We searched MEDLINE, CINAHL, and Cochrane Library database for articles published between January 1990 and December 2012. The update of this clinical practice guideline is based on 237 clinical trials, 54 reviews, and 23 meta-analyses on blood gas analysis (BGA) and hemoximetry. The following recommendations are made following the Grading of Recommendations Assessment, Development, and Evaluation scoring system. BGA and hemoximetry are recommended for evaluating a patient's ventilatory, acid-base, and/or oxygenation status. BGA and hemoximetry are suggested for evaluating a patient's response to therapeutic interventions. BGA and hemoximetry are recommended for monitoring severity and progression of documented cardiopulmonary disease processes. Hemoximetry is recommended to determine the impact of dyshemoglobins on oxygenation. Capillary BGA is not recommended to determine oxygenation status. Central venous BGA and hemoximetry are suggested to determine oxygen consumption in the setting of early goal-directed therapies. For the assessment of oxygenation, a peripheral venous P(O2) is not recommended as a substitute for an arterial blood measurement (P(aO2)). It is not recommended to use venous P(CO2) and pH as a substitute for arterial blood measurement of P(aCO2) and pH. It is suggested that hemoximetry is used in the detection and evaluation of shunts during diagnostic cardiac catheterization.

Effects of a 1:1 Inspiratory to Expiratory Ratio on Respiratory Mechanics and Oxygenation during One-Lung Ventilation in the Lateral Decubitus Position

Prolonged inspiratory to expiratory (I:E) ratio ventilation may have both positive and negative effects on respiratory mechanics and oxygenation during one-lung ventilation (OLV), but definitive information is currently lacking. We therefore compared the effects of volume-controlled ventilation with I:E ratios of 1:1 and 1:2 on respiratory mechanics and oxygenation during OLV. Fifty-six patients undergoing thoracoscopic lobectomy were randomly assigned volume-controlled ventilation with an I:E ratio of 1:1 (group 1:1, n=28) or 1:2 (group 1:2, n=28) during OLV. Arterial and central venous blood gas analyses and respiratory variables were recorded 15 minutes into two-lung ventilation, at 30 and 60 minutes during OLV, and 15 minutes after two-lung ventilation was re-initiated. Peak and plateau airway pressures in cmH2O [standard deviation] during OLV were significantly lower in group 1:1 than in group 1:2 (P <0.01) (19 [3] and 23 [4]; 16 [3] and 19 [5], respectively). The arterial to end-tidal carbon dioxide tension difference was significantly lower in group 1:1 than in group 1:2 (P <0.01), (0.5 [0.3] and 1.1 [0.5]). There were no significant differences in PaO2 during OLV between the two groups (OLV30, P=0.856; OLV60, P=0.473). In summary, volume-controlled ventilation with an I:E ratio of 1:1 reduced peak and plateau airway pressures improved dynamic compliance and efficiency of alveolar ventilation, but it did not improve arterial oxygenation in a substantial manner. Furthermore, the associated increase in mean airway pressure might have reduced cardiac output, resulting in a lower central venous oxygen saturation.

Prophylaxis of TUR-P syndrome with CVP messurement and blood gas analysis During combination Transcervical-Laparoscopic Resection of Endometrium

Objective To observe the changes of central venous pressure and blood gas analysis during combination transcervical-lanaroscopic resection of endometrium. Methods We used 0.9% saline solution as distending medium for 24 cases of operative hysteroscopy. Those patients were divided into two groups, In group CVP, the patients were contineous measured CVP during the operation, when the CVP was higher than 12mmHg, the blood gas was also measured and intravenous lasix. and in group non-CVP, the time was longer than 60 minutes. Plasma sodium, potassium, and PH value were measured. When plasma potassiumwas lower than nomal value, also gave lasix to the patients. Results None of the CVP group cases presented with transurethral resection of prostate ( TURP ) syndrome. But 2 cases of non-CVP patients presented with TURP syndrome. Plasma potassium ( 2.8 ± 0.40 ) mmol/L and PH value ( 7.2 ±0.17 )were found lower in non-CVP group patients than in CVP group patientg P＜ 0. 05 ). Conclusions CVP measurement and blood gas analysis were safe and iand could be widely applied in combination transcervical-laparscopic resection of large endometrium. Key words: Combination Transcervica-Laparoscopic Resection of Endometrium; Central veneous pressure; Blood gas analysis; TURP syndrome

Mismatch of arterial and central venous blood gas analysis during haemorrhage

Arterial base excess and lactate levels are key parameters in the assessment of critically ill patients. The use of venous blood gas analysis may be of clinical interest when no arterial blood is available initially. Twenty-four pigs underwent progressive normovolaemic haemodilution and subsequent progressive haemorrhage until the death of the animal. Base excess and lactate levels were determined from arterial and central venous blood after each step. In addition, base excess was calculated by the Van Slyke equation modified by Zander (BE(z)). Continuous variables were summarized as mean +/- SD and represent all measurements (n = 195). Base excess according to National Committee for Clinical Laboratory Standards for arterial blood was 2.27 +/- 4.12 versus 2.48 +/- 4.33 mmol(-l) for central venous blood (P = 0.099) with a strong correlation (r(2) = 0.960, P < 0.001). Standard deviation of the differences between these parameters (SD-DIFBE) did not increase (P = 0.355) during haemorrhage as compared with haemodilution. Arterial lactate was 2.66 +/- 3.23 versus 2.71 +/- 2.80 mmol(-l) in central venous blood (P = 0.330) with a strong correlation (r(2) = 0.983, P < 0.001). SD-DIFLAC increased (P < 0.001) during haemorrhage. BE(z) for central venous blood was 2.22 +/- 4.62 mmol(-l) (P = 0.006 versus arterial base excess according to National Committee for Clinical Laboratory Standards) with strong correlation (r(2) = 0.942, P < 0.001). SD-DIFBE(z)/base excess increased (P < 0.024) during haemorrhage. Central venous blood gas analysis is a good predictor for base excess and lactate in arterial blood in steady-state conditions. However, the variation between arterial and central venous lactate increases during haemorrhage. The modification of the Van Slyke equation by Zander did not improve the agreement between central venous and arterial base excess.

Effect of passive pneumoperitoneum on oesophageal pressure, cardiovascular parameters and blood gas analysis in horses

Standing surgical procedures are being employed to an ever-greater extent in horses. Pneumoperitoneum during abdominal surgery might adversely affect the work of breathing. To determine whether development of pneumoperitoneum during abdominal surgery adversely influences the work of breathing. Eight healthy mature horses were equipped with carotid artery and thoracic vena cava catheters and an intraluminal manometry system. The following measurements were obtained before and at +5, +10, +15 and +30 min following establishment of pneumoperitoneum by paralumbar puncture using an 8 gauge needle: vital signs, oesophageal pressure, gastric pressure, arterial and central venous blood pressures, and arterial and mixed venous blood gas analyses. Significant changes in oesophageal pressure, central venous pressure and results of arterial and mixed venous blood gas analysis were not detected. Arterial diastolic and mean pressures and rectal temperature increased slightly (P ≤ 0.05). Passive pneumoperitoneum did not adversely affect breathing mechanics or haemodynamic variables under experimental conditions. Changes in arterial pressure could have occurred as a response to the passive pneumoperitoneum or be related to handling stress. Subtle variations in rectal temperature were not clinically relevant and likely resulted from stress associated with restraint. It is unlikely that mature horses will develop signs of respiratory difficulty as a result of the development of passive pneumoperitoneum during standing laparoscopy.

A comparison of central venous and arterial base deficit as a predictor of survival in acute trauma

Background The arterial base deficit has been demonstrated to be a marker of shock and predictive of survival in injured patients. The venous blood, however, may better reflect tissue perfusion. Its usefulness in trauma is unknown. We compared central venous with arterial blood gas analysis to determine which was a better predictor of survival in injured patients. Methods A prospective, nonrandomized series of acutely injured patients was investigated. Patients who had an arterial blood gas analysis for acid-base determination had a simultaneous central venous blood gas analysis and routine blood tests. Patient demographics, Injury Severity Score, and survival past 24 hours were recorded. Arterial and venous blood samples were analyzed for pH, P co 2, P o 2, HCO 3, hemoglobin-oxygen saturation, base deficit, and lactate. Results One hundred patients were enrolled. There were 76 survivors and 24 nonsurvivors. Wilcoxon rank sum test and multivariate logistic regression were used for each recorded variable; only central venous base deficit was predictive of survival past 24 hours ( P = .0081). Specifically, arterial base deficit was not predictive of survival past 24 hours. Conclusion In a prospective series of acutely injured patients, central venous base deficit, not arterial base deficit, was predictive of survival past 24 hours.

Changes in central venous pressure and blood lactate concentration in response to acute blood loss in horses

To evaluate selected hemodynamic, blood gas, and biochemical responses to mild to moderate acute blood loss in standing, awake horses. Prospective study. 7 healthy mares. Each horse was restrained in standing stocks, and its head was maintained in a neutral position; sedatives and tranquilizers were not administered. During a 1-hour period, blood was collected into collection bags by use of a suction pump. The rate of blood collection was approximately 16 mL/kg/h (7.3 mL/lb/h). Thirty minutes after blood collection, the blood was readministered at the same rate. Central venous pressure (CVP), central venous blood gas, blood lactate concentration, and heart rate were measured at baseline (after placement of catheters), after removal of blood, and after readministration of blood. In response to blood loss, CVP decreased and blood lactate concentration increased significantly, compared with baseline values; heart rate and results of central venous blood gas analysis did not change significantly. After readministration of blood, CVP returned to baseline value and blood lactate concentration approached baseline value. Changes in CVP and blood lactate concentration appear to be early indicators of hypovolemia in horses, which may represent acute blood loss in trauma patients; these variables should be monitored to assess the potential need for blood transfusions. These variables can be used to monitor responses of horses to blood transfusions when whole blood is administered as the replacement fluid.

Comparison of two methods to assess blood CO2 equilibration curve in mechanically ventilated patients

In order to compare two mathematical methods to assess the blood CO2 equilibration curve from a single blood gas analysis [Loeppky, J.A., Luft, U.C., Fletcher, E.R., 1983. Quantitative description of whole blood CO2 dissociation curve and Haldane effect. Resp. Physiol. 51, 167-181; Giovannini, I., Chiarla, C., Boldrini, G., Castagneto, M., 1993. Calculation of venoarterial CO2 concentration difference. J. Appl. Physiol. 74, 959-964], arterial and central venous blood gas analyses and oximetry were performed before and after ventilatory resetting, at constant arterial O2 saturation, in 12 mechanically ventilated patients. CO2 equilibration curves obtained from basal arterial blood gas analyses were used to predict arterial CO2 content after ventilatory resetting and vice versa. Internal consistency was very good for both methods and comparable. Method 2 also yielded excellent predictions of changes of arterial pH associated with ventilatory resetting. In determining Haldane effect, method 2 yielded very stable results within the expected range of values, while method 1 yielded a wider spread of results. Method 2 appeared more suitable to determine the Haldane effect in the conditions of the study, probably due to an approach minimizing the effect of potential sources of inaccuracy.

Estimation of Arterial pH and pCO 2 from Central Venous Samples

any papers over the last few years have disagreed about the value of venous blood-gas and pH measurements [7, 13, 15, 18, 201. Some have gone so far as to say that “central venous blood gas analysis may substitute for arterial puncture in assessing the metabolic acid-base status of the patient” [13], while others state that “reliance upon venous blood samples for analysis of blood gas parameters can no longer be justified in the care of the acutely ill patient” [15]. We thus set out to define the limitations of central venous blood gases. We also wanted to determine if, in addition to arterial values, central venous blood gases could help in the management of a complicated case.