End-tidal carbon dioxide partial pressure to assess the value of passive leg-raising test in predicting volume responsiveness in patients with septic shock / 中华危重病急救医学

Objective:To investigate the value of partial pressure of end-tidal carbon dioxide (P ETCO 2) combined with passive leg raising test (PLR) in predicting volume responsiveness in patients with septic shock. Methods:A total of 43 patients with septic shock admitted to the second department of critical care medicine, People's Hospital of Xinjiang Uygur Autonomous Region from December 2019 to June 2021 were selected as the research subjects. P ETCO 2, cardiac index (CI), stroke volume variation (SVV), mean arterial pressure (MAP) and other hemodynamic indexes were monitored before and after PLR and volume stress test (VE). Subjects were grouped according to the CI variation rate (ΔCI) after VE test. Patients with ΔCI ≥ 15% were the responding group, and patients with ΔCI < 15% were the non-responding group. The receiver operator characteristic curve (ROC curve) was drawn to analyze the evaluation value of the change in P ETCO 2 after PLR on the evaluation value of fluid responsiveness. Results:Among the 43 patients, 22 cases were in the responding group, accounting for 51.2%; 21 cases were in the non-responding group, accounting for 48.8%. After the PLR test, the change values of MAP, SVV, CI and P ETCO 2 in the responding group were higher than those in the non-responding group, and the differences were statistically significant [MAP (mmHg): 3.8±2.1 vs. 1.4±2.0, SVV (%): -5.3±2.5 vs. 2.7±2.0, CI (mL·s -1·m -2): 0.48±0.13 vs. 0.14±0.18, P ETCO 2 (mmHg): 3.4±1.8 vs. 1.1±1.0, all P < 0.05, 1 mmHg≈0.133 kPa]. After the VE test, the changes of HR, MAP, SVV, CI and P ETCO 2 in the responding group were higher than those in the non-responding group [HR (times/min): -8.3±2.8 vs. -2.3±3.7, MAP (mmHg): 3.8±2.4 vs. 1.2±1.7, SVV (%): -6.3±3.1 vs. -3.3±2.0, CI (mL·s -1·m -2): 0.51±0.14 vs. 0.16±0.12, P ETCO 2 (mmHg): 3.3±1.2 vs. 1.3±1.1, all P < 0.05]. The area under the ROC curve (AUC) of the change in P ETCO 2 before and after the PLR test (ΔP ETCO 2 PLR) for evaluating fluid responsiveness was 0.881. When the critical value was 5.9%, the sensitivity was 76.7%, the specificity was 89.5%, and the correct index was 0.68; the AUC for SVV baseline assessment of fluid responsiveness was 0.835, and when the cut-off value was 12.8%, the sensitivity was 84.6%, the specificity was 80.0%, and the correct index was 0.65. The predictive value of ΔP ETCO 2 was not lower than the SVV baseline. Conclusion:After the PLR test, the change of P ETCO 2 can be used as a non-invasive, simple, safe and reliable indicator for predicting the volume responsiveness of patients with septic shock.

The value of cardiopulmonary resuscitation quality index in evaluating the prognosis during cardiopulmonary resuscitation / 中华急诊医学杂志

Objective To explore the timeliness value of cardiopulmonary resuscitation quality index (CQI) in patients' prognostic evaluation during cardiopulmonary resuscitation (CPR).Methods A prospective descriptive study was conducted.According to whether they got return of spontaneously circulation (ROSC) or not,45 patients receiving CPR were divided into the ROSC group and non-ROSC group.The changes of CQI and partial pressure of end-tidal carbon dioxide (PETCO2) during CPR were collected,and were analyzed to valuate the prognosis of patients.Results The initial,end,and average PETCO2 were statistically different between the ROSC group and the non-ROSC group [7.0(3.6,14.6) vs 7.0(3.6,14.6) mmHg;29.5(19.8,35.9) vs 4.0(2.3,10.2)mmHg;and 22.2(11.8,36.3) vs 4.0(2.5,9.0) mmHg,respectively;P＜0.05],and the end CQI was statistically different between the two groups (59.6±8.9 vs 34.8±5.2,P＜0.05).The CQI differences between the two groups initiated at 11 min after CPR,and stopped at 29 min after CPR.The optimal cut-offpoint of terminal CQI and PETCO2 for prognostic was 33.2 and 16.1 mmHg respectively,and there was a statistically difference in the area under the curve between them (P＜0.05).Conclusions During CPR,both CQI and PETCO2 can be used to evaluate the prognosis,and CQI is more capable of predicting in the late stage of CPR.

The Effect of Pneumoperitoneum and Trendelenburg position on respiratory mechanics under general anesthesia during gynecological laparoscopic surgery / Монголын Анагаах Ухаан

Background@#Gynecological laparoscopic surgery requires pneumoperitoneum(PP) with CO₂ gas insufflation and Trendelenburg position. Pneumoperitoneum and Trendelenburg position may impact intraoperative respiratory mechanics in anesthetic management.The goal of this study was to evaluate the influence of Pneumoperitoneum and Trendelenburg position on respiratory mechanics and ventilation. @*Methods@#Twenty one patients scheduled for elective gynecological laparoscopy were evaluated. The patients had no preexisting lung and heart disease or pathologic lung function. Conventional general anesthesia with thiopental sodium, fentanyl, аtracrium and isoflurane was administered. The peak inspiratory pressure, plateau pressure, and end-tidal CO₂ were compared before after creation of pneumoperitoneum with an intraabdominal pressure of 15 mmH₂O, then after PP10, PP20, PP30 minutes in the 20° Trendelenburg position, and after deflation of pneumoperitoneum. The dynamic lung compliance was calculated.@*Results@#During of pneumoperitoneum, there were a significant increase in peak inspiratory pressure by 6 cmH₂O, plateau pressure by 5 cmH₂O, while dynamic lung compliance decreased by 11 ml/cmH₂O. General, the Trendelenburg position induced no significant hemodynamic and pulmonary changes.@*Conclusion@#The effects of pneumoperitoneum significantly reduced dynamic lung compliance and increased peak inspiratory and plateau pressures. The Tredelenburg position did not change these parameters. The end-tidal CO₂ significantly increased after pneumoperitoneum and CO₂ deflation.

Predictive value of partial pressure of end-tidal carbon dioxide on the effect of active abdominal compression-decompression cardiopulmonary resuscitation and serum S100B protein on cerebral function / 中华危重病急救医学

Objective To explore the predictive value of partial pressure of end-tidal carbon dioxide (PETCO2) on the effect of active abdominal compression-decompression cardiopulmonary resuscitation (AACD-CPR) and serum S100B protein on cerebral function. Methods 142 adult patients with in-hospital cardiac arrest (IHCA) AACD-CPR in Zhengzhou People's Hospital, Affiliated Southern Medical University from September 2014 to December 2017 were enrolled. Patients were divided into successful group and failure group according to restoration of spontaneous circulation (ROSC) or not; and then according to Glasgow-Pittsburgh cerebral performance categories (CPC) one month after ROSC, the successful group was divided into good prognosis group (CPC 1-2) and poor prognosis group (CPC 3-5) further. The variations of hemodynamic, arterial blood gas index, PETCO2and serum S100B protein level (25 healthy subjects as normal S100B protein level reference value) during the recovery were analyzed. The predictive value of PETCO2on the effect of AACD-CPR and serum S100B protein on cerebral function of successful resuscitation patients were analyzed by receiver operating characteristic curve (ROC). Results ① According to the traditional qualitative indexes, such as pulsation of the large artery, redness of lips and extremities, spontaneous fluctuation of chest, narrowing of pupil, existence of shallow reflex, etc, 54 in 142 patients with IHCA were successfully resuscitated; 57 cases were successfully resuscitated through the guidance of PETCO2, there was no significant difference between the two groups (χ2= 0.133, 1 = 0.715). With the AACD-CPR, 142 CA patients' arterial partial pressure of oxygen (PaO2), arterial blood carbon dioxide partial pressure (PaCO2) were all improved with different degrees; heart rate (HR), mean arterial pressure (MAP), PaO2and PaCO2were further improved at 20 minutes after ROSC. At beginning of AACD-CPR, PETCO2of both groups were about 10 mmHg (1 mmHg = 0.133 kPa). PETCO2was gradually rising to above 20 mmHg in successful group during AACD-CPR process; the failed group increased slightly within 2-5 minutes, then gradually decreased to below 20 mmHg, there was a significant difference in PETCO2between the two groups at each time. The area under the ROC (AUC) of PETCO2at CPR 20 minutes in predicting the outcome of the resuscitation was 0.969, 95% confidence interval (95%CI) was 0.943-0.995 (1 = 0.000), when the cut-off value of PETCO2was 24.25 mmHg, the sensitivity was 90.7%, and the specificity was 96.6%. ② The level of serum S100B protein at 0.5 hour after ROSC in the good prognosis group and the poor prognosis group were significant higher than that of the normal control group; there was no significant difference between poor prognosis group and good prognosis group. S100B protein concentration of the poor prognosis group reached the peak within 3-6 hours, then gradually decreased, and was higher than that of the normal control group at ROSC 72 hours; the good prognosis was gradually decreased and recovered to normal control group within ROSC 72 hours. The AUC of S100B at 3 hours after ROSC on cerebral function prognosis prediction was 0.925, 95%CI was 0.867-0.984 (1 = 0.000), when the cut-off value of S100B protein was 1.215 μg/L, the sensitivity was 85.2%, and the specificity was 85.5%. Conclusion The variation of PETCO2can be used as an objective index to predict the success of AACD-CPR, and serum S100B protein can be used as an objective clinical index to predict cerebral function after AACD-CPR, both of which have some reference and guiding significance for clinical treatment.

The causes and management of carbon dioxide embolism in laparoscopic hepatectomy / 中华肝胆外科杂志

Objective To investigate the strategies in dealing with intraoperative CO2 embolizm during Laparoscopic hepatectomy (LH).Methods We collected and analyzed data from patients who underwent laparoscopic hepatectomy (LH) in our hospital from Jan.2013 to Aug.2017.There were 321 patients.The criteria for the diagnosis of CO2 embolism were rapid intraoperative decrease in petCO2 and SPO2 accompanied with tachyarrhythmia.Results 12 patients were diagnosed to have CO2 embolism.The rate was 3.7％.For these 12 patients,10 patients were dealt with laparoscopically and 2 patients were converted to open surgery.Conclusion CO2 embolism did not rarely occur in LH patients.Sophisticated operations and careful manipulation in LH are the only ways to prevent CO2 embolism.

Predictive value of continuous monitoring end-tidal carbon dioxide partial pressure on in-hospital resuscitation outcome: secondary analysis of the data from a multicenter observational study / 中华危重病急救医学

Objective To approach the predictive value of continuous monitoring end-tidal carbon dioxide partial pressure (PETCO2) on the outcome of in-hospital cardiopulmonary resuscitation (CPR), and explored the indicators of termination of resuscitation. Methods A secondary analysis of a multicenter observational study data was conducted. The screening aim was adult non-traumatic in-hospital CPR patients whose PETCO2were recorded within 30 minutes of CPR. Clinical information was reviewed. The mean PETCO2in restoration of spontaneous circulation (ROSC) and non-ROSC patients was recorded. The outcome of CPR was continuously assessed by PETCO2≤ 10 mmHg (1 mmHg = 0.133 kPa) for 1, 3, 5, 8, 10 minutes. Receiver operating characteristic (ROC) curve was plotted, and the predictive value of PETCO2≤ 10 mmHg for different duration on the outcome of CPR was evaluated. Results A total of 467 recovery patients, including 419 patients with complete recovery were screened. Patients who were out-of-hospital resuscitation, non-adults, traumatic injury, had no PETCO2value, PETCO2value failed to explained the clinical conditions, or patients had not monitored PETCO2within 30 minutes of resuscitation were excluded, and finally 120 adult patients with non-traumatic in-hospital resuscitation were enrolled in the analysis. The mean PETCO2in 50 patients with ROSC was significantly higher than that of 70 non-ROSC patients [mmHg: 17 (11, 27) vs. 9 (6, 16), P < 0.01]. ROC curve analysis showed that the area under ROC curve (AUC) of PETCO2during the resuscitation for predicting recovery outcome was 0.712 [95% confidence interval (95%CI) = 0.689-0.735]; when the cut-off was 10.5 mmHg, the sensitivity was 57.8%, and the specificity was 78.0%, the positive predictive value (PPV) was 84.6%, and negative predictive value (NPV) was 46.9%. The duration of PETCO2≤ 10 mmHg was used for further analysis, which showed that with PETCO2≤10 mmHg in duration, the prediction of the sensitivity of the patients failed to recover decreased from 58.2% to 28.2%, but specificity increased from 39.4% to 100%; PPV increased from 40% to 100%, and NPV decreased from 57.5% to 34.2%. Conclusion For adult non-traumatic in-hospital CPR patients, continuous 10 minutes PETCO2≤10 mmHg may be an indicate of termination of CPR.

Relationship between cerebral oxygen saturation and hemodynamics under different end-tidal carbon dioxide partial pressure in children with ventricular septal defect / 中华实用儿科临床杂志

Objective To study the relationship between regional cerebral tissue oxygen saturation (rScO2) and hemodynamic parameters under different end-tidal carbon dioxide partial pressure (PetCO2) levels during anesthesia induction period in children undergoing ventricular septal defect(VSD) repair.Methods A total of 25 patients aged from 2 to 37 months (median 6 months) were enrolled,who received selective VSD repair at Beijing Anzhen Hospital from April to May 2017.After admission,anesthesia induction and intubation,invasive radial artery pressure were established routinely and hemodynamic device-MostCare was used,Fore-Sight was used to monitor rScO2 of the right frontal brain.By means of adjusting mechanical ventilation parameter,PetCO2 was maintained at 30 (T1),35 (T2),40 (T2),45 (T3) mmHg(1 mmHg =0.133 kPa) in sequence.Pulse oxygen saturation (SpO2),heart rate (HR),systolic pressure (SysP),difference between dicrotic pressure (DicP) and diastolic pressure (DiaP) (Pdic-a),stroke volume index (SVI),cardiac index (CI),systemic vascular resistance index (SVRI),and pulse pressure variation (PPV) were recorded at T1,T2,T3 and T4.Results (1) Comparison among groups:rScO2 at T4,T3,T2 and T1 were (80.5 ± 4.0) ％,(78.2 ± 4.6) ％,(74.4 ± 5.7) ％,(70.8 ± 6.5) ％,respectively,rScO2 at T2,T3 and T4 were higher than that at T1,and the differences were statistically significant (all P ＜ 0.05).SysP at T3 [(85 ± 9) mmHg] and T4 [(84 ± 10) mmHg] were lower than that at T1 [(92 ± 15) mmHg],and the differences were statistically significant (all P＜0.05).DicP at T2[(64 ± 12) mmHg],T3[(60 ± 10) mmHg],and T4 [(59 ±9) mmHg] were significantly lower than that at T1 [(68 ± 15) mmHg],and the differences were statistically significant (all P ＜ 0.05).DiaP at T2 [(44 ± 6) mmHg],T3[(41 ±6) mmHg],and T4 [(41 ±6) mmHg]were lower than that at T1 [(47 ±7) mmHg],and the differences were statistically significant(all P ＜ 0.01).SVRI at T4 [(1 382 ± 262) dyne · s cm-5 · m2] was significantly lower than those at T1 [(1 486 ± 241) dyne · s cm-5 · m2],T2 [(1 440 ± 279) dyne · s cm-5 · m2] and T3 [(1 418 ±266) dyne · s cm-5 · m2],and the differences were statistically significant (all P ＜ 0.05).PPV at T3 [(11 ± 4) ％] and T4 [(13 ± 5) ％] was significantly lower than that at T1 [(18 ± 12) ％],and the differences were statistically significant (all P ＜ 0.05).(2) Correlation analysis:in total population,PetCO2 was positively correlated with rScO2 (r =0.582,P ＜ 0.01).At T1,rScO2 was positively correlated with DiaP and DicP (r =0.600,0.658,all P ＜ 0.01),as well as SysP,CI,SVI,Pdic-a (r =0.460,0.424,0.522,0.534,all P ＜ 0.05),rScO2 was negatively correlated with HR and PPV (r =-0.450,-0.490,all P ＜ 0.05).At T2,rScO2 was positively correlated with DiaP and DicP (r =0.689,0.692,all P ＜ 0.01),as well as SysP,SVI (r =0.534,0.445,all P ＜ 0.05).At T3,rScO2 was positively correlated with SysP (r =0.495,P ＜ 0.05),and negatively correlated with PPV (r =-0.562,P ＜ 0.01).At T4,the rScO2 was not correlated with any hemodynamic parameters (P ＞ 0.05).Conclusions During anesthesia induction in ventricular septal defect children,rScO2 increases significantly with the increase in PetCO2.When PetCO2 is at 30 and 35 mmHg,rScO2 is mainly affected by hemodynamics.When PetCO2 is at 40 and 45 mmHg,rScO2 is mainly affected by PetCO2,but less affected by hemodynamics.

Relationship between end-tidal carbon dioxide tension obtained from the distal ends of the tracheal tube and arterial pressure of carbon dioxide with the side stream capnometerin infants with congenital heart disease / 临床麻醉学杂志

Objective To determine the relationship between end-tidal carbon dioxide tension (PET CO 2 )obtained from the distal ends of the tracheal tube and arterial pressure of carbon dioxide (PaCO 2 ) compared with the sidestream capnometer in infants with congenital heart disease. Methods Twenty infants undergoing congenital heart disease surgery,12 males and 8 females,aged 3-48 months,ASA physical statusⅠ-Ⅲ were enrolled.Measurements of PET CO 2 were obtained from the distal ends of the tracheal tube using a sterile 22 G catheter that was inserted into the tube and from the proximal end with a sidestream capnometer in 20 intubated infants with congenital heart dis-ease.The data including PET CO 2 and the arterial PaCO 2 were obtained both after the anesthesia induc-tion and the CPB.Results The data of PET CO 2 obtained from the distal ends of the tracheal tube after the anesthesia induction [(36.8 ±2.7)mm Hg vs.(32.5 ± 1.4)mm Hg,P <0.05 ]and the CPB [(40.8±2.5)mm Hg vs.(36.5±1.6)mm Hg,P <0.05]were both higher than those from the proximal end with a sidestream capnometer.The difference between PaCO 2 and PET CO 2 obtained from the distal ends of the tracheal tube after the induction [(7.1 ±0.7)mm Hg vs.(1 1.4 ± 1.5 ) mm Hg,P <0.01]and the CPB [(9.3±1.2)mm Hg vs.(13.5±2.3)mm Hg,P <0.01]were sig-nificantly lower than that between PaCO 2 and PET CO 2 obtained from the proximal end.Distal side-stream PET CO 2 correlated with the PaCO 2 (R 2 =0.94 after induction and R 2 =0.93 after the CPB,P<0.05).However,the proximal PET CO 2 with the sidestream capnometer correlated very poorly with PaCO 2 whether after the induction (R 2 = 0.68,P < 0.05 )nor the CPB (R 2 = 0.66,P < 0.05 ). Conclusion We conclude that the PET CO 2 obtained from the distal ends of the tracheal tube provides accurate estimates of the PaCO 2 in critically ill infants with congenital heart disease.

The value of end -tidal carbon dioxide partial pressure in fluid resuscitation in severe acute pancreatitis patients / 中国基层医药

Objective To investigate the value of end-tidal carbon dioxide partial pressure (PET CO2 )in fluid resuscitation in severe acute pancreatitis(SAP)patients.Methods SAP patients under mechanical ventilation with the need of a fluid challenge test were included.Hemodynamic parameter cardiac index(CI)and PET CO2 were conducted before and after the fluid challenge test.The value of ΔPET CO2 was used to predict fluid responsiveness. Results Totally 43 patients with SAP were prospectively recruited.31 patients had volume responsiveness, 12 patients had no volume responsiveness.Compared with no volume responsiveness group,volume responsiveness group led to a greater increase in ΔCI[(0.9 ±0.3)vs.(0.2 ±0.3),t =3.24,P <0.05]and ΔPET CO2 [(4.1 ± 1.9)vs.(0.7 ±1.2),t =4.01,P <0.05].ΔPET CO2 and ΔCI were correlated(r =0.74,P <0.05).The area under ROC curve of ΔPET CO2 was 0.872(95% CI 0.754 ~0.923,P <0.05).An increase of 5% in ΔPET CO2 predicted fluid responsiveness with a sensitivity of 86.7%,and specificity of 89.5%.Conclusion The change of ΔPET CO2 induced by fluid challenge test is an effective way to predict fluid responsiveness in SAP patients.

The value of end-tidal carbon dioxide partial pressure combined passive leg raising test on volume responsiveness assessment in shocked patients post cardiac operation / 中华危重病急救医学

Objective To assess the value of end-tidal carbon dioxide partial pressure (PETCO2) combined passive leg raising (PLR) test on volume responsiveness assessment in shocked patients post cardiac operation.Methods A prospective,self-controlled,and observational study was conducted.The shocked patients post cardiac operation undergoing complete mechanical ventilation admitted to Department of Critical Care Medicine of First Affiliated Hospital of College of Medicine,Zhejiang University from June 2014 to October 2015 were enrolled.PETCO2 and hemodynamic parameters including stroke volume variation (SVV),cardiac index (CI),mean arterial pressure (MAP) monitored by a pulse indicator continuous cardiac output (PiCCO) were determined before and after PLR and volume expansion (VE).Volume responsiveness was defined as an increase in CI (△ CI) of 15％ or greater after VE,namely response group (△ CI ≥ 15％) and non-response group (△ CI ＜ 15％).The value of PLR-induced PETCO2 change (△PETCO2 PLH) to predict volume responsiveness was evaluated by receiver operating.characteristic curves (ROC).Results Among the 41 patients enrolled,21 had volume responsiveness (response group),and 20 had no responsiveness (non-response group).After PLR,the changes in CI and PETCO2 were both significantly increased in the response group compared with non-response group [△ CI:(13.5 ± 4.6)％ vs.(3.6± 3.5)％,△ PETCO2:(7.4 ± 3.4)％ vs.(2.8 ± 2.5)％,both P ＜ 0.05].△ PETCO2 PLR and baseline SVV were positively correlated with PLR-induced CI change (△ CI PLR) (r1 =0.50,r2 =0.38,both P ＜ 0.05).VE-induced PETCO2 change (△ PETCO2 VE),baseline SVV and △ CI PLR were positively correlated with VE-induced CI (△ CI VE) (r1 =0.58,r2 =0.56 and r3 =0.84,all P ＜ 0.01).The area under ROC curve (AUC) of △ PETCO2 PLR was 0.875±0.054 [95％ confidence interval (95％CI) =0.769-0.981,P ＜ 0.05].△ PETCO2 PLR ≥ 5.8％ predicted volume responsiveness with sensitivity of 76.2％ and specificity of 90.0％.AUC of △CI PLR was 0.933±0.036 (95％CI =0.862-1.000,P ＜ 0.05).△CI PLR ≥ 10.4％ predicted volume responsiveness with sensitivity of 81.0％ and specificity of 90.0％.AUC of baseline SVV was 0.831 ±0.066 (95％CI =0.702-0.960,P ＜ 0.05).Baseline SVV ≥ 12.5％ predicted volume responsiveness with sensitivity of 85.7％ and specificity of 75.0％.Conclusion The change in PETCO2 induced by PLR is a convenient,reliable and non-invasive indicator to predict volume responsiveness in shocked patients post cardiac operation with mechanical ventilation.

The target adjustment of the end-tidal carbon dioxide partial pressure in preterm infants under mechanical ventilation / 中华实用儿科临床杂志

Objective To reduce the incidence of the hypocapnia,the cutoff value of the end-tidal carbon dioxide partial pressure[Pet(CO2)] for predicting the hypocapnia so as to understand the suitable adjustment target and target range of the Pet(CO2) in preterm infants under mechanical ventilation.Methods From Jan.2012 to Oct.2013,96 cases of the preterm infants with respiratory distress syndrome(RDS) who needed mechanical support were selected from the Huaian Maternity and Child Health Care Hospital.Pet(CO2) value of each time point(1 h,24 h,48 h and 72 h after mechanical ventilation) were recorded,while radial artery blood was collected for blood gas analysis.The level of pa (CO2) ＜ 35 mmHg(1 mmHg =0.133 kPa) diagnosed hypocapnia;while the level of Pa (CO2) ＞ 60 mmHg was for diagnosing hypercapnia.The diagnostic cutoff and the suitable adjustment target and adjustment target range of the Pet(CO2) were confirmed by receiver operating characteristic (ROC) curve.Results The data from 381 arterial blood gas analysis results were gained,of which 151 times belonged to hypocapnia,and the rate was 39.6％,the other 230 cases were normal,and no case was of hypercapnia.The area under the ROC curve was 0.895,and the area of the standard error was 0.016.There was a statistical significance in Pet(CO2) value for the diagnosis of hypocapnia(P =0.000).The lower the value of Pet (CO2),the greater the likelihood of hypocapnia,and 95 ％ confidence interval area was 0.864-0.926.The Pet (CO2) optimal diagnostic cutoff value determined in accordance with Youden index was 30.5 mmHg.When Pet (CO2) among 41.5 mmHg,sensitivity was 100％.Conclusions Diagnostic cutoff value for forecasting hypocapnia is 30.5 mmHg.The suitable adjustment target of mechanical ventilation parameter adjustment is 41.5 mmHg for the Pet(CO2).The target range of mechanical ventilation parameter adjustment is 30.6-41.5 mmHg for the Pet(CO2).

Development of portable end-tidal carbon dioxide monitor / 医疗卫生装备

Objective To develop a portable end-tidal carbon dioxide monitor for the patient's physiological monitoring during the process of the first aid and transport.Methods MCU was used as the core of the control system to communicate with the ETCO2 detection module and the SD memory module. The power supply module and software system were realized for the monitor.Results The monitor had high stability, reliability and performances.Conclusion The monitor meets the desired requirements, and can be used for the monitoring of the patients during first aid or transportation.

Changes of end-tidal carbon dioxide during cardiopulmonary resuscitation from ventricular fibrillation versus asphyxial cardiac arrest / 世界急诊医学杂志（英文）

BACKGROUND:Partial pressure of end-tidal carbon dioxide (PETCO2) has been used to monitor the effectiveness of precordial compression (PC) and regarded as a prognostic value of outcomes in cardiopulmonary resuscitation (CPR). This study was to investigate changes of PETCO2 during CPR in rats with ventricular fibrillation (VF) versus asphyxial cardiac arrest. METHODS:Sixty-two male Sprague-Dawley (SD) rats were randomly divided into an asphyxial group (n=32) and a VF group (n=30). PETCO2 was measured during CPR from a 6-minute period of VF or asphyxial cardiac arrest. RESULTS:The initial values of PETCO2 immediately after PC in the VF group were significantly lower than those in the asphyxial group (12.8±4.87 mmHg vs. 49.2±8.13 mmHg,P=0.000). In the VF group, the values of PETCO2 after 6 minutes of PC were significantly higher in rats with return of spontaneous circulation (ROSC), compared with those in rats without ROSC (16.5±3.07 mmHg vs. 13.2±2.62 mmHg,P=0.004). In the asphyxial group, the values of PETCO2 after 2 minutes of PC in rats with ROSC were significantly higher than those in rats without ROSC (20.8±3.24 mmHg vs. 13.9±1.50 mmHg,P=0.000). Receiver operator characteristic (ROC) curves of PETCO2 showed significant sensitivity and specificity for predicting ROSC in VF versus asphyxial cardiac arrest. CONCLUSIONS:The initial values of PETCO2 immediately after CPR may be helpful in differentiating the causes of cardiac arrest. Changes of PETCO2 during CPR can predict outcomes of CPR.

The role of end-tidal carbon dioxide partial pressure in fluid responsiveness assessment in septic shock patient / 中华内科杂志

Objective To assess whether end-tidal carbon dioxide partial pressure (PET CO2) can predict the fluid responsiveness in septic shock patients.Methods Septic shock patients under mechanical ventilation without spontaneous breathing and with the need of a fluid challenge test were included in this study.Heart rate,central venous pressure,pulse pressure,PErCO2,and CI before and after the fluid challenge test were conducted in all the patients.Results Of the 48 septic shock patients included,34 had preload responsiveness,14 had no responsiveness.△CI and △PET CO2 after the fluid challenge test involume responders were (0.85 ± 0.47) L · min-1 · m-2 and (3.5 ± 2.5) mmHg respectively,which were higher than those in no volume responders (P ＜ 0.05).The fluid-induced changes in PET CO2 and CI were correlated (r =0.072,P ＜ 0.05).The AUCRoc of fluid challenge-induced △PET CO2 as the predictor for volume responsiveness was 0.943,and its sensitivity was 87.9％ and specificity was 93.4％ with a critical value of 5％.The AUCRoc of △PP as the predictor for volume responsiveness was 0.801,and its sensitivity was 68.1％ and specificity was 73.2％ with a critical value of 10％.Conclusion The changes of PETCO2 induced by a fluid challenge test can predict fluid responsiveness with reliability,and have a better sensitivity and specificity than the changes of PP.

The value of changes in end-tidal carbon dioxide pressure induced by passive leg raising test in predicting fluid responsiveness in mechanically ventilated patients with septic shock / 中华内科杂志

Objective To test whether the changes of partial end-tidal carbon dioxide pressure (PETCO2) during passive leg raising (PLR) predict fluid responsiveness in mechanically ventilated patients with septic shock.Methods Forty-two mechanically ventilated patients with septic shock admitted from January 2012 to November 2012 were prospectively recruited.Hemodynamic parameters monitored by a pulse indicator continuous cardiac output(PiCCO) device and PETCO2 monitored by an expiratory-CO2 device were studied at baseline,after PLR,and after volume expansion.Fluid responsiveness was defined as an increase in cardiac index (CI) of 15％ or greater after volume expansion.The correlation between PLR-induced CI change (△CIPLR) and PETCO2 (△PETCO2-PLR) was analyzed.The value of △PETCO2-PLR to predict fluid responsiveness was evaluated by receiver operating characteristic (ROC) curves.Results A total of 42 patients were enrolled in this study,of whom,24 had a CI increase of ≥ 15％ after volume expansion (responders).After PLR,CI and PETCO2 were both significantly increased in the response group compared with baseline [(21.4 ± 12.9) ％ of CI and (9.6 ± 4.7) ％ of PETCO2,P ＜ 0.05],while no significant changes were observed (P ＞ 0.05) in the non-response group.Both △CIPLR and △PETCO2-PLR were significantly higher in responder group than in the non-responder group (both P ＜ 0.05).△CI and △PETCO2 after PLR were strongly correlated (r =0.64,P ＜ 0.05).In responders after PLR,the area under ROC curve of △PETCO2-PLR was 0.900 ± 0.056 (95％ CI 0.775-1.000,P ＜ 0.05).An increase of ≥ 5％ in △PETCO2-PLR predicted fluid responsiveness with a sensitivity of 88.0％ and specificity of 88.2％.Conclusions The change of PETCO2 induced by passive leg raising is a non-invasive and easy way to predict fluid responsiveness in mechanically ventilated patients with septic shock.

Monitoring changes of partial pressure of end-tidal carbon dioxide ( PetCO2 ) levels during cardiopulmonary resuscitation / 中国小儿急救医学

During cardiopulmonary resuscitation (CPR),PetCO2 monitoring helps to judge the status of circulation.Marked elevation of PetCO2 level is early sign for restoration of spontaneous circulation and successful CPR.PetCO2 level monitoring can predict probability of CPR success and it is also helpful to assist in confirming endotracheal tube placement,to assess for chest compression and ventilation.PetCO2 levels should be monitored during CPR.

Titrating positive end-expiratory pressure after recruitment maneuver according to end-tidal carbon dioxide and its related indicators in acute respiratory distress syndrome dog model / 中华内科杂志

Objective To investigate the relationship between end-tidal carbon dioxide with its related indicators and ventilation/perfusion of the acute respiratory distress syndrome (ARDS) lung,and to explore a feasible way to titrate positive end-expiratory pressure (PEEP) in clinical practice.Methods Five mixed-breed dogs with oleic acid lung injury model were mechanically ventilated at a serial PEEP trial including a recruitment maneuver (RM) before each PEEP level changed.The value of blood dynamics,end-tidal carbon dioxide partial pressure ( PetCO2 ) and arterial carbon dioxide pressure under different PEEP levels were recorded.Arterial end-tidal carbon dioxide gradient (Pa-etCO2) and dead space fraction (Vd/Vt％) were calculated.All dogs received CT scan.Lung volume under different pressure levels,and ratio and volume of alveolar closing pressure,collapsed alveoli,sufficiently and insufficiently ventilated alveoli were obtained.Alveolar opening and closing analysis were performed by non-liner regression equation.Results The mean pressure when Vd/Vt％ obtained lowest level were ( 11.2 ± 4.4 ) cm H2O(1 em H2 O =0.098 kPa),which had no significant difference when compared to alveolar closing pressure[ ( 11.5 ± 3.2 ) cm H2O ]( P ＞ 0.05 ).The fraction of insufficiently ventilated and collapsed alveoli showed a significant linear correlation with the Vd/Vt％ when PEEP was lower than Pmin ( r =0.632,P =0.004 ).There was a linear correlation between the Vd/Vt％ and the fraction of over-distended alveoli when PEEP was higher than Pmin ( r =0.770,P =0.001 ).Conclusions Closing pressure is in accordance with PEEP level after RM having reached the best ventilation/circulation ratio.The characteristics of lung collapse can be revealed by Vd/Vt％ changes after RM.To titrate PEEP for the lowest Vd/Vt％ after RM may be a feasible way to match the best ventilation and circulation effects of PEEP.

Sudden decrease in end-tidal carbon-dioxide in a neonate undergoing surgery for type B interrupted aortic arch.

Interruption of the aortic arch is a rare anomaly affecting 1% of children with congenital heart disease. The systemic circulation is ductal dependent and is determined principally by the ratio of the resistances in the systemic and the pulmonary vascular bed. Any increase in the pulmonary vascular resistance may increase the dead space ventilation due to acute pulmonary hypoperfusion. We report a case where sudden decreases in the end-tidal carbon-dioxide due to pulmonary hypoperfusion mimicked accidental endotracheal tube extubation in an infant undergoing repair of interrupted aortic arch.

Guide and prediction value of partial pressure of end-tidal carbon dioxide during cardiopulmonary resuscitation / 中华急诊医学杂志

Objective To study the clinical significance of end-tidal carbon dioxide partial pressure (PetCO2 ) during cardiopulmonary resuscitation (CPR) and seek the fixed value according which to decide if we should and when to give up.Methods This was a prospective,observational study.A total of 124 patients with cardiac arrest in or out-of-hospital from may 2003 to March 2009 in emergency department of our hospital were selected.All of them had definite etiological factors.Changes of PetCO2 in 124 cardiac arrest patients during CPR were tracked.Results The gender,age,rescue time in seventy-one patients with the return of spontaneous circulation (ROSC) after endotracheal intubation have a significant difference with that in fifty-three patients without ROSC (P ＜0.01 ).The PetCO2 of the survival were higher than that of patients without ROSC or with ROSC,but finally died (P ＜0.01 ).A fixed point 14.4 mmHg of PetCO2 after 20 minutes' CPR can be used as a reference value to guide CPR or predict prognosis.Conclusions Monitoring PetCO2 during CPR has a predictive value on the success of resuscitation.

Clinical significance of end-tidal carbon dioxide tension monitoring during mechanical ventilation / 中国小儿急救医学

End-tidal carbon dioxide tension or concentration monitoring is characterized with noninvasive,convenient and fast reaction,which Can be continuously monitored and dynamically displayed On electrocardiogram monitor.The technique has been extensively applied in the operation room,intensive care unit and emergency room.