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Objective:To explore the clinical value of arterial partial pressure of carbon dioxide (PaCO 2) combined with Wells score in predicting acute pulmonary embolism (PE). Methods:Patients with suspected acute PE admitted to Emergency Department of Beijing Chaoyang Hospital, Capital Medical University from January 1, 2016 to August 31, 2021 were screened. Patients with positive computed tomography pulmonary angiography (CTPA) results were classified as the PE group, and those with negative CTPA results were classified as the non-PE group. Demographic characteristics, symptoms, vital signs, underlying diseases, risk factors for venous thrombosis, arterial blood gas analysis and Wells scores were statistically analyzed and compared between the two groups, and the clinical efficacy of PaCO 2 combined with Wells score in predicting acute PE was evaluated. Results:A total of 1 869 patients with suspected acute PE were screened, and 1 492 patients were finally selected. There were 537 cases in the PE group and 955 cases in the non-PE group. The frequency of chest pain, dyspnea, unilateral lower limb edema, history of PE or deep venous thrombosis, history of surgery or immobilization within 3 months, history of fracture within 3 months, active malignant tumor, elevated Wells score and reduced PaCO 2 in the PE group was significantly higher than that in the non-PE group (all P< 0.05). The area under receiver operating characteristic (ROC) curve (AUC) of Wells score was 0.784 (95% CI: 0.758-0.810), and the sensitivity and specificity of predicting acute pulmonary embolism were 61.64% and 88.48%, respectively. The AUC of reduced PaCO 2 was 0.679 (95% CI: 0.651-0.707), and the sensitivity and specificity of predicting acute pulmonary embolism were 79.89% and 55.92%, respectively. The AUC of reduced PaCO 2 combined with Wells score was 0.837 (95% CI: 0.816-0.858), and the sensitivity and specificity of predicting acute pulmonary embolism were 74.12% and 77.07%, respectively. The AUC of reduced PaCO 2 combined with Wells score was significantly greater than the AUC of Wells score ( P<0.001) and the AUC of reduced PaCO 2 ( P<0.001). Conclusions:The efficacy of PaCO 2 reduction combined with Wells score in predicting acute PE was superior to that of either of them alone. This was a beneficial supplement to the screening of patients with acute PE, and would also help reduce the abuse of CTPA in the emergency department.
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Objective:To investigate the effect of inferior vena cava variability (IVCV) combined with difference of central venous-to-arterial partial pressure of carbon dioxide (Pcv-aCO 2) on guiding fluid resuscitation in septic shock. Methods:Patients with septic shock admitted to the department of critical care medicine of Jiangxi Provincial People's Hospital from January 1, 2018 to December 31, 2020 were enrolled, and they were divided into control group and observation group according to random number table method. Patients in both groups were given fluid resuscitation according to septic shock fluid resuscitation guidelines. The patients in the control group received fluid resuscitation strictly according to the early goal-directed therapy (EGDT) strategy. Resuscitation target: central venous pressure (CVP) 12-15 cmH 2O (1 cmH 2O≈0.098 kPa), mean arterial pressure (MAP) > 65 mmHg (1 mmHg≈0.133 kPa), mean urine volume (UO) > 0.5 mL·kg -1·h -1, central venous oxygen saturation (ScvO 2) > 0.70. In the observation group, the endpoint of resuscitation was evaluated by IVCV dynamically monitored by bedside ultrasound and Pcv-aCO 2. Resuscitation target: fixed filling of inferior vena cava with diameter > 2 cm, IVCV < 18%, and Pcv-aCO 2 < 6 mmHg. The changes in recovery indexes before and 6 hours and 24 hours of resuscitation of the two groups were recorded, and the 6-hour efficiency of fluid resuscitation, 6-hour lactate clearance rate (LCR) and 6-hour and 24-hour total volume of resuscitation were also recorded; at the same time, the duration of mechanical ventilation, length of intensive care unit (ICU) stay, 28-day mortality and the incidence of acute renal failure and acute pulmonary edema between the two groups were compared. Results:A total of 80 patients were enrolled in the analysis, with 40 in the control group and 40 in the observation group. The MAP, CVP and ScvO 2 at 6 hours and 24 hours of resuscitation in the two groups were significantly higher than those before resuscitation, while Pcv-aCO 2 and blood lactic acid (Lac) were significantly decreased, and UO was increased gradually with the extension of resuscitation time, indicating that both resuscitation endpoint evaluation schemes could alleviate the shock state of patients. Compared with before resuscitation, IVCV at 6 hours and 24 hours of resuscitation in the observation group were decreased significantly [(17.54±4.52)%, (18.32±3.64)% vs. (27.49±10.56)%, both P < 0.05]. Compared with the control group, MAP and ScvO 2 at 6 hours of resuscitation in the observation group were significantly increased [MAP (mmHg): 69.09±4.64 vs. 66.37±4.32, ScvO 2: 0.666±0.033 vs. 0.645±0.035, both P < 0.05], 24-hour MAP was increased significantly (mmHg: 75.16±3.28 vs. 70.12±2.18, P < 0.05), but CVP was relatively lowered (cmH 2O: 9.25±1.49 vs. 10.25±1.05, P < 0.05), indicating that the fluid resuscitation efficiency was higher in the observation group. Compared with the control group, 6-hour LCR in the observation group was significantly increased [(55.64±6.23)% vs. (52.45±4.52)%, P < 0.05], 6-hour and 24-hour total volume of resuscitation was significantly decreased (mL: 2 860.73±658.32 vs. 3 568.54±856.43, 4 768.65±1 085.65 vs. 5 385.34±1 354.83, both P < 0.05), the duration of mechanical ventilation was significantly shortened (days: 6.78±3.45 vs. 8.45±2.85, P < 0.05), while the incidence of acute pulmonary edema was significantly decreased [2.5% (1/40) vs. 20.0% (8/40), P < 0.05]. There was no significant difference in the length of ICU stay, 28-day mortality or incidence of acute renal failure between the two groups. Conclusions:Dynamic monitoring of IVCV and Pcv-aCO 2 can effectively guide the early fluid resuscitation of patients with septic shock, and compared with EGDT, it can significantly shorten the duration of mechanical ventilation, reduce the amount of fluid resuscitation, and reduce the incidence of acute pulmonary edema. Combined with its non-invasive characteristics, it has certain clinical advantages.
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Objective To analysis the transcutaneous carbon dioxide pressure(TcpCO2 )in very low birth weight infant (VLBW) and extremely low birth weight infant (ELBW) after the time of tube drawing, and further guidance the management of premature ventilator breathing. Methods Premature infants with gestational age less than 32 weeks, birth weight below 1 500 g, hospitalized from March 2016 to December 2018 in our hospital,who needed early mechanical ventilation due to respiratory distress within 24 hours after birth and intended to be withdrawn were enrolled. Fifty-five infants in the observation group were monitored by TcpCO2 and blood gas was collected at 1 h, 6 h, 12 h, 24 h, 48 h, and 72 h after weaning;55 infants in the control group were collected arterial blood gas only. When TcpCO2 monitoring and PaCO2 indicated hy-percapnia, clinical intervention was actively given. The value of blood gas PaCO2 in the two groups and the TcpCO2 value of the observation group were recorded at different time points (1 h, 6 h, 12 h, 24 h, 48 h, 72 h) after weaning,and the failure of weaning was recorded in both group. Results There was no significant difference in the general information ( gender, gestational age, birth weight, and whether prenatal maternal glucocorticoids) between the two groups ( P>0. 05). There were no significant differences in mechanical ventilation time, noninvasive ventilation mode and time between the two groups(P>0. 05). The failure rate of withdrawal within 24 h and 72 h was lower in the observation group than the control group[3. 6% (2/55) vs. 14. 0% (8/55), 7. 3% (4/55) vs. 21. 0% (12/55)], the difference was statistically significant ( P< 0. 05). There was a significant difference in blood gas PaCO2 between the two groups at 6 h, 12 h, and 24 h after weaning (P<0. 05), but had no significant difference between the two groups at 1 h, 48 h, and 72 h (P>0. 05). The values of TcpCO2 and PaCO2 had no significant difference in the observation group at the same time point (P>0. 05),and there was a correlation between them(r＝0. 761, P<0. 05). Conclusion VLBW and ELBW undergoing mechanical ventilation are given continuous TcpCO2 monitorings after wea-ning, which not only has the characteristics of continuous and non-invasive monitoring, but also help to iden-tify hypercapnia early and give symptomatic treatment,and reduce the incidence of weaning failure. And it proves a good correlation between TcpCO2 and PaCO2 .
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Objective@#To analysis the transcutaneous carbon dioxide pressure(TcpCO2)in very low birth weight infant (VLBW) and extremely low birth weight infant (ELBW) after the time of tube drawing, and further guidance the management of premature ventilator breathing.@*Methods@#Premature infants with gestational age less than 32 weeks, birth weight below 1 500 g, hospitalized from March 2016 to December 2018 in our hospital, who needed early mechanical ventilation due to respiratory distress within 24 hours after birth and intended to be withdrawn were enrolled.Fifty-five infants in the observation group were monitored by TcpCO2 and blood gas was collected at 1 h, 6 h, 12 h, 24 h, 48 h, and 72 h after weaning; 55 infants in the control group were collected arterial blood gas only.When TcpCO2 monitoring and PaCO2 indicated hypercapnia, clinical intervention was actively given.The value of blood gas PaCO2 in the two groups and the TcpCO2 value of the observation group were recorded at different time points (1 h, 6 h, 12 h, 24 h, 48 h, 72 h) after weaning, and the failure of weaning was recorded in both group.@*Results@#There was no significant difference in the general information (gender, gestational age, birth weight, and whether prenatal maternal glucocorticoids) between the two groups (P>0.05). There were no significant differences in mechanical ventilation time, noninvasive ventilation mode and time between the two groups(P>0.05). The failure rate of withdrawal within 24 h and 72 h was lower in the observation group than the control group[3.6% (2/55) vs.14.0% (8/55), 7.3% (4/55) vs. 21.0% (12/55)], the difference was statistically significant (P<0.05). There was a significant difference in blood gas PaCO2 between the two groups at 6 h, 12 h, and 24 h after weaning (P<0.05), but had no significant difference between the two groups at 1 h, 48 h, and 72 h (P>0.05). The values of TcpCO2 and PaCO2 had no significant difference in the observation group at the same time point (P>0.05), and there was a correlation between them(r=0.761, P<0.05).@*Conclusion@#VLBW and ELBW undergoing mechanical ventilation are given continuous TcpCO2 monitorings after weaning, which not only has the characteristics of continuous and non-invasive monitoring, but also help to identify hypercapnia early and give symptomatic treatment, and reduce the incidence of weaning failure.And it proves a good correlation between TcpCO2 and PaCO2.
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Objective To investigate the correlation between mixed venous oxygen saturation(SVO2),mixed venous-arterial partial pressure of carbon dioxide[P(v-a)CO2] and blood lactate(LAC) with the Acute Physiology and Chronic Health Evaluation Ⅱ (APACHE Ⅱ) score and Sequential Organ Failure Assessment (SOFA) score,and to investigate the value of SVO2,P(v-a)CO2,LAC in assessing the disease condition.Methods A total of 104 patients with heart operation in the Chengdu Municipal Third People's Hospital from December 2011 to March 2015 were collected and divide into survival group and non-survival group according to the prognosis.The correlation between SvO2,P(v-a)CO2 and LAC with the APACHE Ⅱ score and SOFA score was analyzed by using the Pearman correlation analysis.The correlation between SvO2,P(v-a)CO2 and LAC with the disease condition was also analyzed.The Receiver Operating Characteristic (ROC) curvewas utilized to evaluating the accuracy of SvO2,P(v-a)CO2 and LAC for assessing the prognosis.Results Compared with the survival group,the difference of P(v-a)CO2,LAC,APACHE Ⅱ scores in the non-survival group had statistical significance(P＜0.05).SOFA score was 11.22 vs.7.35 (t=-3.433,P＜0.01),all were significantly increased,but SvO2 was significantly decreased(0.65 vs.0.71,t=2.794,P＜0.05).The values of SvO2 and LAC were significantly correlated with SOFA score (r=-0.268,P=0.006;r=0.200,P =0.041).But P(v-a) CO2 had no correlation with SOFA score(r=0.190,P=0.054).The values of SvO2,P(v-a)CO2 and LAC were correlated with APACHE Ⅱ score(r=-0.3,76,P=0.000;r=0.282,P=0.004;r=0.264,P =0.007).The values of SvO2,P (v-a) CO2 and LAC were correlated with prognosis (r=0.308,P=0.001;r=-0.248,P=0.011;r=-0.400,P=0.000).The areas under ROC curve of SvO2,P(v-a)CO2 and LAC corresponding practical mortality all were less than 0.70.Conclusion SvO2,P(v-a)CO2 and LAC have a certain correlation with the APACHE Ⅱ score,SOFA score and severity of disease condition,but which can not serve as the evaluation indicators of prognosis.
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Objective To compare the clinical effect of unarmed cardiopulmonary resuscitationand cardiopulmonary resuscitationmachine in the emergency room.Methods One hundred cases patients with cardiopulmonary arrest in Hainan Agricultural Reclamation General Hospital from February 2014 to February 2016 were analyzed.The control group(n=50) were given unarmed cardiopulmonary resuscitation,while thetest group(n=50) were given ardiopulmonary resuscitation machine.Two groups' before and after cardiopulmonary resuscitation of arterial blood gas index(oxygen saturation (SaO2),C02 partial pressure (PaC02),oxygen partial pressure(Pa02)),cardiopulmonary resuscitation effectiveness and the success rate,and complications were compared.Results Before cardiopulmonary resuscitation,there were no significant differences on arterial blood gas index (SaO2,PaCO2,PaO2) between the two groups (t =0.069,0.097,0.121,P ＞ 0.05).After cardiopulmonary resuscitation,the SaO2,PaO2 of the test group were higher than that of the control group ((98.60± 8.51) ％ vs.(86.37 ± 7.84) ％,(13.84 ± 1.40) kPa vs.(8.69± 1.21) kPa),while PaCO2 of test group was lower than the control group ((3.24 ± 0.56) kPa vs.(6.41 ± 0.87) kPa),the differences were significant(t =7.474,21.665,19.679,P ＜ 0.05).The cardiopulmonary resuscitation of effective rate,success rate of test group were higher than the control group (84.00％ (42/50) vs.62.00％ (31/50),26.00％ (13/50)vs.10.00％(5/50),x2=6.139,4.336,P＜0.05).The total complication rate of the test group was lower than the control group(8.00％ (4/50) vs.28.00％ (14/50)),the difference was significant (x2 =6.775,P ＜0.05).Conclusion The clinical effect of cardiopulmonary resuscitation machine is significantly superior to unarmed cardiopulmonary resuscitation,which can effectively improve the patient's arterial blood gas state,improve the efficiency and success rate of cardiopulmonary resuscitation,and reduce the complications.
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Background: The valley of Kashmir lies at an average height of 1730 m above the sea level with a barometric pressure of 624 mmHg. The fall in atmospheric pressure at higher altitude decreases the partial pressure of inspired oxygen and hence the driving pressure for gas exchange in the lungs. At sea level the normal range of PaCO2 is 35 mmHg to 45 mmHg and at 1500m above sea level (barometric pressure 634 mmHg), the predicted normal PaO2 in a healthy young adult is approximately 80 mmHg; this contrasts with a value close to 95 mmHg at sea level. On these grounds this study was undertaken to formulate normal ABG values for this place as it lies at a higher altitude. Methods: The study was undertaken to measure "arterial blood gases" (ABG) in ethnic Kashmiri population and consisted of a sample of one hundred healthy Kashmiri subjects of either sex after proper inclusion and exclusion by spirometrically measuring Vital Capacity and Forced expiratory volume in one second/Forced vital capacity (Fev1/FVC). A modified Allen's test was performed to check for adequate collateral circulation ruling out Ischemia. Results: The average mean PaO2 of 78.51 ± 4.40 mmHg and the average mean PaCO2 of 33.37 ± 2.38 mmHg was obtained of the volunteers of both the sexes. The average mean pH of males (7.43 ± 0.02) was significantly lower than the mean pH of females (7.45 ± 0.021). Conclusions: The present study might provide useful base line normal values of Arterial Blood Gases for the local population and will be beneficial to the clinicians.
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ObjectiveTo evaluate the effect of auscultation, partial pressure of carbon dioxide in end-expiration (PETCO2), transillumination technique to judge whether the endotracheal tube is misplaced into the esophagus. Methods A blinded randomized controlled trial was conducted. Sixty patients with American Society of Anesthesiology (ASA) gradeⅠ-Ⅱundergoing endotracheal intubation in Fengxian Central Hospital admitted from September 2014 to February 2015 were enrolled. Two endotracheal tubes with the same size were respectively inserted into the trachea and esophagus for the same depth after general anesthesia by the same person. Two blinded anesthetists with different experience checked the tube position using three methods including auscultation, PETCO2, and transillumination technique, respectively. The order of the tubes tested (trachea or esophagus) and the method used were randomized according to randomise numbers table. The experienced anesthetists conducted the test first, followed by an inexperienced anesthetist conducting the same methods. The numbers of right and wrong determinations with different methods by different anesthetists were recorded.Results Sixty patients underwent the procedures for 180 times, with intratracheal intubation for 90 times, and esophageal intubation for 90 times. It was shown that the results were not different in two groups [96.7% (174/180) vs. 92.2% (166/180),χ2 = 3.500,P = 0.057]. By using auscultation, the correct rate of experienced anesthetist was higher than that of inexperienced (95.0% vs. 78.3%,χ2 = 5.786,P = 0.013). Using PETCO2, both anesthetists were correct in all cases, and the accuracy was 100%. Using transillumination, the experienced anesthetist was mistaken in 3 cases (accuracy was 95.0%), while the inexperienced mistook in 1 case (accuracy was 98.3%), and no significant difference was found between two groups (χ2 = 0.500,P = 0.250). The correct rate of using transilluminaion was significantly higher than that of using auscultation (χ2 = 7.563,P = 0.004). The sensitivity and specificity of the auscultation was 70.0% and 80.0%, that of transillumination technique was 96.7% and 93.3%,and PETCO2 was 100%, respectively, for two groups.ConclusionsPETCO2 is the most reliable method for determining tube position, and it is superior to auscultation and transilluminaion. Transillumintaion technique is superior to auscultation, irrespective of anesthetists' experience, while the accuracy of auscultation showed an obvious relationship with the anesthetists' experience.
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Objective To explore the clinic values of early goal directed treatment (EGDT)with the target of mixed venous oxygen saturation (SvO2)and difference of mixed venous-arterial partial pressure of carbon dioxide (Pv-aCO2) in monitoring of oxygen metabolism and treatment for patients post open-heart operation. Methods A prospective study was conducted. The adult patients admitted to Third People's Hospital of Chengdu from December 2011 to March 2014 with SvO22 mmol/L when admitted in intensive care unit(ICU)were selected on whom elective open-heart operation and pulmonary artery catheter examination were done. All patients received EGDT with the target of SvO2≥0.65 and Pv-aCO2<6 mmHg (1 mmHg=0.133 kPa)and were divided into three groups by the values of SvO2 and Pv-aCO2 at 6-hour after ICU admission:A group with SvO2≥0.65 and Pv-aCO2<6 mmHg,B group with SvO2≥0.65 and Pv-aCO2≥6 mmHg,and C group with SvO2<0.65. Then the changes and prognosis of the patients in different groups were observed. Results 103 cases were included,44 in A group,31 in B group and 28 in C group. The acute physiology and chronic health evaluationⅡ (APACHEⅡ)score in group A were significantly lower than that in group B or C at 6,24,48 and 72 hours (T6,T24,T48,T72)of ICU admission (T6:11.4±5.8 vs. 13.9±5.4,13.7±6.4;T24:8.8±3.7 vs. 10.8±4.8,11.8±5.4;T48:8.7±4.1 vs. 9.6 ±4.2,10.2 ±5.1;T72:7.5 ±3.4 vs. 8.6 ±2.9,9.2 ±4.2,all P<0.05),and the sequential organ failure assessment (SOFA)showed the same tendency (T6:6.5±4.3 vs. 8.0±3.8,9.1±4.5;T24:6.6±3.6 vs. 8.6±3.9, 8.5±3.3;T48:5.2±3.4 vs. 7.0±3.6,7.6±5.1;T72:4.6±2.4 vs. 5.8±2.5,6.8±3.5,all P<0.05). The values of blood lactic acid (mmol/L)in group A and B were significant lower than that in group C at T6,T24,T48 and T72 (T6:1.60 ±0.95,2.20 ±1.02 vs. 2.55 ±1.39;T24:2.26 ±1.26,2.70 ±1.36 vs. 3.34 ±2.36;T48:2.01 ±1.15, 2.17 ±1.51 vs. 2.42 ±1.63;T72:1.62 ±1.14,1.64 ±0.75 vs. 2.11 ±1.29,all P<0.05). The time of machine ventilation(days)in group A or B was significantly shorter than that in group C(2.8±2.0,3.6±2.3 vs. 5.0±3.1,both P<0.05). ICU day (days)in group A was significant shorter than that in group C (4.6±2.5 vs. 6.5±3.7,P<0.05). The 7-day mortalities after operation in three groups were significantly different. Compared with group A (2.3%),the odds ratio (OR)in group B (22.6%)was 12.5 (P<0.05),group C (25.0%)14.3 (P<0.05). The morbidity and 28-day mortality in three groups were not significantly different. Pv-aCO2 negatively correlated with cardiac index(CI, r=-0.685,P=0.000),but not correlated with blood lactic acid(r=0.187,P=0.080). Conclusions EGDT with the target of SvO2≥0.65 and Pv-aCO2<6 mmHg improved the general condition and tissue hypoxia,shortened the time of machine ventilation and duration of hospitalization in ICU,and decrease the 7-day mortality.
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Objective To study the changes in and correlations between the partial pressure of end-tidal carbon dioxide (PETCO2) and the coronary perfusion pressure during cardio-pulmonary resuscitation (CPR) based on the cardiac arrest dog models of ventricular fibrillation by electric shock. Methods 36 healthy dogs were evenly randomized into 3 groups including 4 minutes close-chest CPR(CCCPR) group, 4 minutes open-chest CPR(OCCPR) group, and 8 minutes OCCPR group. There were 12 dogs in each group, half male and half female. In the process of CPR, all parameters about PETCO2 and CPP were recorded. Results In the 4 minutes CCCPR group, the correlation coefficient between the CPP and the PETCO2 was 0.992 (P<0.05), which was in positive linear correlation. In the 4 minutes OCCPR group, the correlation coefficient between the CPP and the PETCO2 was 0.937 (P < 0.05), which also showed positive linear correlation. In the 8 minutes OCCPR group, the correlation coefficient between the CPP and the PETCO2 was 0.952 (P<0.05), and was also in positive linear correlation. The percentage of ROSC was 66.7(8/12) in the 4 minutes CCOPR group, 100%(12/12) in the 4 minutes OCCPR group and 58.3%(7/12) in the 8 minutes OCCPR group. There were statistical differences in CPP, PETCO2 between models with ROSC and without ROSC at 1, 2, 5, 10, 15 and 20 mins of CPR (all P<0.05). Conclusions This research shows that there is a close positive linear relationship between the coronary perfusion pressure and the PETCO2, and PETCO2 could be used to evaluate the prognosis of the CPR.
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Objective To evaluate the implementation of the early goal-directed therapy after cardiopulmonary resuscitation in Suzhou area,in order to provide clinical data for standardized post resuscitation care.Methods This retrospective study included comatose survivors of CA,admitted into intensive care units (ICU) of 10 hospitals in Suzhou area between January 2009 and December 2010.the parameters,mean arterial pressure (MAP),peripheral oxygen saturation (SpO2),partial pressure of carbon dioxide (PaCO2),blood glucose (Glu) and body temperature (T),were collected for 48 h after CA.The percentage of parameters achieving recommended goals was compared.Results A total of 101 CA patients were enrolled in this study.Among the parameters of GDT,the percentage of achieving recommended goals for SpO2 and MAP was 90.1％ and 81.4％ ; the percentage of achieving recommended goals for Glu and PaCO2 was 55.4％ and 32.8％ ; however,mild therapeutic hypothermia (MTH) reached the lowest percentage,only 10％ ; there were significant differences in the percentage of achieving recommended goals for these parameters,P ＜0.01.Conclusions The quality of early goal-directed therapy in the CA patients should be improved,especially in the management of body temperature and partial pressure of carbon dioxide.
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Objective To know the correlation about PetCO_2 and PaCO_2, the meanings of PetCO_2monitoring in respiratory failure patients with mechanical ventilation, and then summarize the related nurs-ing points. Methods Divided 112 patients in ICU into the A group(58 eases) and the B group(54 cas-es) according to their station of hemodynamics. Mechanical ventilation were used in both the two groups,PetCO_2 and PaCO_2 were monitored at the same time, and then observed the correlation of PetCO_2 and Pa-CO_2 in both the two groups. Results There was a significant corrlation in the A group about PetCO_2 and PaCO_2, while the correlation in the B group was not significant. Conclusions PetCO_2 and PaCO_2 had sat-isfactory corrlation in patients with stable hemedynamies, PetCO_2 monitoring can take place of PaCO_2 in these patients with its sensitive, atraumatic, consecutive and convient merits.