Differences In PaCO2 Research Articles

Non-invasive carbon dioxide monitoring in patients with cystic fibrosis during general anesthesia: end-tidal versus transcutaneous techniques.

The gold standard for measuring the partial pressure of carbon dioxide remains arterial blood gas (ABG) analysis. For patients with cystic fibrosis undergoing general anesthesia or polysomnography studies, continuous non-invasive carbon dioxide monitoring may be required. The current study compares end-tidal (ETCO2), transcutaneous (TCCO2), and capillary blood gas carbon dioxide (Cap-CO2) monitoring with the partial pressure of carbon dioxide (PaCO2) from an ABG in patients with cystic fibrosis. Intraoperatively, a single CO2 value was simultaneously obtained using ABG (PaCO2), capillary (Cap-CO2), TCCO2, and ETCO2 techniques. Tests for correlation (Pearson's coefficient) and agreement (Bland-Altman analysis) were performed. Data were further stratified into two subgroups based on body mass index (BMI) and percent predicted forced expiratory volume in 1s (FEV1%). Additionally, the absolute difference in the TCCO2, ETCO2, and Cap-CO2 values versus PaCO2 was calculated. The mean ± SD differences were compared using a paired t test while the number of times the values were ≤ 3mmHg and ≤ 5mmHg from the PaCO2 were compared using a Fishers' exact test. The study cohort included 47 patients (22 males, 47%) with a mean age of 13.4 ± 7.8years, median (IQR) BMI of 18.7kg/m2 (16.7, 21.4), and mean FEV1% of 87.3 ± 18.3%. Bias (SD) was 4.8 (5.7) mmHg with Cap-CO2 monitoring, 7.3 (9.7) mmHg with TCCO2 monitoring, and 9.7 (7.7) mmHg with ETCO2 monitoring. Although there was no difference between the degree of bias in the population as a whole, when divided based on FEV1% and BMI, there was greater bias with ETCO2 in patients with a lower FEV1% and a higher BMI. The Cap-CO2 vs. PaCO2 difference was 5.2 ± 5.3mmHg (SD), with 16 (48%) ≤ 3mmHg and 20 (61%) ≤ 5mmHg from the ABG value. The TCCO2-PaCO2 difference was 9.1 ± 7.2mmHg (SD), with 11 (27%) ≤ 3mmHg and 15 (37%) ≤ 5mmHg from the ABG value. The ETCO2-PaCO2 mean difference was 11.2 ± 7.9mmHg (SD), with 5 (12%) ≤ 3mmHg and 11 (26%) ≤ 5mmHg from the ABG value. While Cap-CO2 most accurately reflects PaCO2 as measured on ABG, of the non-invasive continuous monitors, TCCO2 was a more accurate and reliable measure of PaCO2 than ETCO2, especially in patients with worsening pulmonary function (FEV1% ≤ 81%) and/or a higher BMI (≥ 18.7kg/m2).

Adaptive mechanical ventilation with automated minimization of mechanical power\u2014a pilot randomized cross-over study

BackgroundAdaptive mechanical ventilation automatically adjusts respiratory rate (RR) and tidal volume (VT) to deliver the clinically desired minute ventilation, selecting RR and VT based on Otis’ equation on least work of breathing. However, the resulting VT may be relatively high, especially in patients with more compliant lungs. Therefore, a new mode of adaptive ventilation (adaptive ventilation mode 2, AVM2) was developed which automatically minimizes inspiratory power with the aim of ensuring lung-protective combinations of VT and RR. The aim of this study was to investigate whether AVM2 reduces VT, mechanical power, and driving pressure (ΔPstat) and provides similar gas exchange when compared to adaptive mechanical ventilation based on Otis’ equation.MethodsA prospective randomized cross-over study was performed in 20 critically ill patients on controlled mechanical ventilation, including 10 patients with acute respiratory distress syndrome (ARDS). Each patient underwent 1 h of mechanical ventilation with AVM2 and 1 h of adaptive mechanical ventilation according to Otis’ equation (adaptive ventilation mode, AVM). At the end of each phase, we collected data on VT, mechanical power, ΔP, PaO2/FiO2 ratio, PaCO2, pH, and hemodynamics.ResultsComparing adaptive mechanical ventilation with AVM2 to the approach based on Otis’ equation (AVM), we found a significant reduction in VT both in the whole study population (7.2 ± 0.9 vs. 8.2 ± 0.6 ml/kg, p < 0.0001) and in the subgroup of patients with ARDS (6.6 ± 0.8 ml/kg with AVM2 vs. 7.9 ± 0.5 ml/kg with AVM, p < 0.0001). Similar reductions were observed for ΔPstat (whole study population: 11.5 ± 1.6 cmH2O with AVM2 vs. 12.6 ± 2.5 cmH2O with AVM, p < 0.0001; patients with ARDS: 11.8 ± 1.7 cmH2O with AVM2 and 13.3 ± 2.7 cmH2O with AVM, p = 0.0044) and total mechanical power (16.8 ± 3.9 J/min with AVM2 vs. 18.6 ± 4.6 J/min with AVM, p = 0.0024; ARDS: 15.6 ± 3.2 J/min with AVM2 vs. 17.5 ± 4.1 J/min with AVM, p = 0.0023). There was a small decrease in PaO2/FiO2 (270 ± 98 vs. 291 ± 102 mmHg with AVM, p = 0.03; ARDS: 194 ± 55 vs. 218 ± 61 with AVM, p = 0.008) and no differences in PaCO2, pH, and hemodynamics.ConclusionsAdaptive mechanical ventilation with automated minimization of inspiratory power may lead to more lung-protective ventilator settings when compared with adaptive mechanical ventilation according to Otis’ equation.Trial registrationThe study was registered at the German Clinical Trials Register (DRKS00013540) on December 1, 2017, before including the first patient.

Effects of bronchial blockers on one-lung ventilation in general anesthesia: A randomized controlled trail.

Background: Double-lumen bronchial tubes (DLBT) and bronchial blockers (BB) are commonly used in the anesthesia for clinical thoracic surgery. But there are few systematic clinical comparisons between them. In this study, the effects of BB and DLBT on one-lung ventilation (OLV) are studied.Methods: The 200 patients with thoracic tuberculosis undergoing thoracic surgery, were randomly assigned to group A (DLBT) and group B (BB). Intubation time, hemodynamic changes (mean arterial pressure [MAP], heart rate [HR]), and arterial blood gas indicators (arterial partial pressure of carbon dioxide [PaCO2], arterial partial pressure of oxygen [PaO2], airway plateau pressure [Pplat], and airway peak pressure [Ppeak]) at 4 time points were recorded. Complications such as hoarseness, pulmonary infection, pharyngalgia, and surgical success rate were also evaluated postoperatively.Results: Intubation times were shorter in group B. Both MAP and HR in group A were significantly higher 1 minute after intubation than before, but also higher than those in group B. PaO2 levels were lower in both groups during (OLV) than immediately after anesthesia and after two-lung ventilation (TLV), with PaO2 being lower after 60 minutes of OLV than after 20 minutes of OLV. Furthermore, at both points during OLV, PaO2 was lower in group A than in group B. No significant differences in PaCO2 were found between the 2 groups. Ppeak and Pplat were increased in both groups during OLV, with both being higher in group A than in group B. The incidence of postoperative hoarseness, pulmonary infection, and pharyngalgia were lower in group B. There was no significant difference in the success rate of operation between the 2 groups.Conclusions: Compare with using DLBT, implementation of BB in general anesthesia has less impact on hemodynamics, PaO2 and airway pressures, and achieves lower incidence of postoperative complication.

Immediate Prone Positioning After Massive Gastric Aspiration Reduces Lung Injury Possibly by Attenuating Interleukin-6-Mediated Lung-Tissue Inflammation in Pigs.

Gastric aspiration, which can cause acute, diffuse, inflammatory lung injury, is of particular concern in critically ill patients. This study aimed to determine the effects of immediate prone positioning on the degree of lung injury and inflammatory response induced by gastric aspiration. Following induction of gastric aspiration by injection of gastric fluid, 16 healthy pigs were randomized to one of two groups: supine position (SP) or prone position (PP). After ventilation and monitoring for 6 hr, all pigs were euthanized. The ratio of the partial pressure of arterial oxygen/fraction of inspired oxygen (PaO2/FIO2) and the partial pressure of arterial carbon dioxide (PaCO2) were recorded during the 6-hr study period. Serum levels of interleukin (IL)-6 were measured every 2 hr, and the mean optical density (MOD) of IL-6 in lung tissues and lung-injury scores were measured at the end of the experiment. The PP group showed a significantly higher PaO2/FIO2 ratio, lower serum IL-6 concentration (p = .015), lower lung-injury scores (p = .012), and lower IL-6 concentration and MOD of IL-6 in lung tissue, especially in dorsal (p = .001, p = .021, respectively) and nondependent regions (p = .005, p = .035, respectively) than the SP group. There were no statistically significant differences in PaCO2 between the groups. Lung-injury severity was positively correlated with the IL-6 concentration and MOD of IL-6 in lung tissues (p < .05). These results suggest that immediate prone positioning alleviated the degree of aspiration-induced lung injury, possibly through mitigating IL-6-mediated lung inflammation.

Laparoscopic and retroperitoneal laparoscopic resection of adrenal tumors in patients with clinical efficacy, blood gas analysis and hemodynamic effects

Objective To investigate the clinical effect, blood gas analysis and hemodynamics of patients with adrenal tumors undergoing laparoscopic and retroperitoneal laparoscopic resections. Methods Ninety patients with adrenal tumors were selected from May 2014 to August 2017 in our hospital and Zhejiang provincial people's hospital and divided into control group and observation group according to the different surgical methods, 43 cases in the control group and 47 cases in the observation group. The patients in the control group underwent laparoscopic surgery and the observation group underwent laparoscopic surgery. The clinical efficacy, blood gas analysis and hemodynamic indexes of the two groups before pneumoperitoneum (T1), 30 min after pneumoperitoneum (T2), 60 min after pneumoperitoneum (T3) and 30 min after pneumoperitoneum (T4) were respectively tested. Results The postoperative drainage, postoperative, hospital stay and intestinal function recovery time in the observation group were significantly lower than those in the control group (P 0.05). At T1, there was no significant difference in MAP and HR between the two groups (P>0.05). At T2 and T3, both MAP and HR levels were significantly higher than those at TI (P 0.05). At T4, MAP and HR in both groups were lower than those at T2 and T3, and there was no significant difference between the two groups (P>0.05), No significant difference between groups (P>0.05); There were no significant differences in PaCO2, PaO2 and PH levels between the two groups at T1 (P>0.05). At T2 and T3, the levels of PaCO2 in both groups were significantly higher than those in T1, and the levels of PH were significantly lower than those in T1 (P 0.05). The PaCO2 level in the observation group were significantly higher than those in the control group (P 0.05), PaCO2 levels in patients were lower than those in T2 and T3, PH levels were higher than those in T2 and T3, and there was no significant difference compared with T1 (P>0.05). There was no significant difference in PaCO2 between T2 and T3 statistical significance (P>0.05), no significant difference between groups (P>0.05). At T2 and T3, the levels of Na+ and HCO3－ in both groups were significantly increased compared with those in T1 and K+ levels were significantly lower than those in T1 (P 0.05). The level of HCO3－ in the observation group was significantly higher than that in the control group (P 0.05). Conclusions Retroperitoneal laparoscopic surgery can produce an effective therapeutic effect on patients with adrenalectomized resection, but it has a greater impact on the patient's blood gas index and should monitor the patient's respiratory and blood gas indexes during surgery. Key words: Adrenal Gland Neoplasms; Laparoscopy; Blood Gas Analysis; Hemodynamics

Chronobiological study of sex differences in the internal environment in zoletil-anaesthetized rats

ABSTRACT Although it is generally assumed that females are not significantly more variable than males, there are studies that have demonstrated that differences may be quite large. The aim of the present in vivo study was to determine the effect of general anaesthesia on the status of acid–base balance in spontaneously breathing rats of both sexes in dependence on the light–dark cycle. The experiments were performed using zoletil-anaesthetized (30mg/kg [intraperitoneal], Virbac, France) female and male Wistar rats, after a four-week adaptation to a light–dark cycle (12 h:12 h). The animals were divided into four experimental groups according to sex and light period (n = 20). The results demonstrated sex differences in acid–base balance, as well as sex-related differences between the light and dark period in zoletil-anaesthetized rats. Both females and males exhibited the same tendency toward changes in the status of acid–base balance in both light periods. The most unfavourable status in the internal environment was exhibited in males during the light period (the lowest pH, the most pronounced hypoxia and hypercapnia), but with the maintenance of light–dark differences. The light–dark differences in paO2 and paCO2 were eliminated in females, not in males. The optimal status of acid–base balance occurred during the dark period in males.

Effect of prolonged inspiratory time on gas exchange during robot-assisted laparoscopic urologic surgery.

Gas exchange disturbance may develop during urologic robotic laparoscopic surgery with the patient in a steep Trendelenburg position. This study investigated whether prolonged inspiratory time could mitigate gas exchange disturbances including hypercapnia. In this randomized cross-over trial, 32patients scheduled for robot-assisted urologic surgery were randomized to receive an inspiratory to expiratory time ratio (I:E) of 1:1 for the first hour of pneumoperitoneum followed by 1:2 for last period of surgery (groupA, n = 17) or I:E of 1:2 followed by 1:1 (groupB, n = 15). Arterial blood gas analysis, airway pressure and hemodynamic variables were assessed at four time points (T1: 10 min after induction of general anesthesia, T2: 1 h after the initiation of pneumoperitoneum, T3: 1 h after T2 and T4: at skin closure). The carry over effect of initial I:E was also evaluated over the next hour through arterial blood gas analysis. There was asignificant decrease in partial pressure of oxygen in arterial blood (PaO2) for both groups at T2 and T3 compared to T1 but in groupB the PaO2 at T4 was not decreased from the baseline. Partial pressure of carbon dioxide in arterial blood (PaCO2) increased with I:E of 1:2 but did not significantly increase with I:E of 1:1; however, there were no differences in PaO2 and PaCO2 between the groups. Decreased oxygenation by pneumoperitoneum was improved and PaCO2 did not increase after 1h of I:E of 1:1; however, the effect of equal ratio ventilation longer than 1h remains to be determined. There was no carryover effect of the two different I:E ratios.

Carbon dioxide dynamics in relation to neurological outcome in resuscitated out-of-hospital cardiac arrest patients: an exploratory Target Temperature Management Trial substudy

BackgroundDyscarbia is common in out-of-hospital cardiac arrest (OHCA) patients and its association to neurological outcome is undetermined.MethodsThis is an exploratory post-hoc substudy of the Target Temperature Management (TTM) trial, including resuscitated OHCA patients, investigating the association between serial measurements of arterial partial carbon dioxide pressure (PaCO2) and neurological outcome at 6 months, defined by the Cerebral Performance Category (CPC) scale, dichotomized to good outcome (CPC 1 and 2) and poor outcome (CPC 3–5). The effects of hypercapnia and hypocapnia, and the time-weighted mean PaCO2 and absolute PaCO2 difference were analyzed. Additionally, the association between mild hypercapnia (6.0–7.30 kPa) and neurological outcome, its interaction with target temperature (33 °C and 36 °C), and the association between PaCO2 and peak serum-Tau were evaluated.ResultsOf the 939 patients in the TTM trial, 869 were eligible for analysis. Ninety-six percent of patients were exposed to hypocapnia or hypercapnia. None of the analyses indicated a statistical significant association between PaCO2 and neurological outcome (P = 0.13–0.96). Mild hypercapnia was not associated with neurological outcome (P = 0.78) and there was no statistically significant interaction with target temperature (Pinteraction = 0.95). There was no association between PaCO2 and peak serum-Tau levels 48 or 72 h after return of spontaneous circulation (ROSC).ConclusionsDyscarbia is common after ROSC. No statistically significant association between PaCO2 in the post-cardiac arrest phase and neurological outcome at 6 months after cardiac arrest was detected. There was no significant interaction between mild hypercapnia and temperature in relation to neurological outcome.

Dual effects of leptin in perioperative gas exchange of morbidly obese patients.

Leptin has shown positive effects on respiratory function in experimental settings. The role of leptin on perioperative respiratory function in morbidly obese patients has not been established. We performed a retrospective analysis of morbidly obese patients undergoing laparoscopic sleeve gastrectomy. Fasting serum leptin and interleukin (IL)-6 were measured preoperatively, and arterial blood gases were obtained pre- and postoperatively. Outcome variables were arterial partial pressure of oxygen (PaO2), arterial partial pressure of carbon dioxide (PaCO2), and differences in PaO2 and PaCO2 between pre- and postoperative values (ΔPaO2, ΔPaCO2; postoperative minus preoperative). Patients with lower (<40 μg/L) and higher (≥40 μg/L) leptin levels were compared. Bravais-Pearson’s correlation, multiple linear regression, and logistic regression analysis were performed. A total of 112 morbidly obese patients were included. Serum leptin was significantly higher in females than in males (42.86±12.89 vs. 30.67±13.39 μg/L, p<0.0001). Leptin was positively correlated with body mass index (r = 0.238; p = 0.011), IL-6 (r = 0.473; p<0.0001), and ΔPaO2 (r = 0.312; p = 0.0008). Leptin was negatively correlated with preoperative PaO2 (r = -0.199; p = 0.035). Preoperative PaO2 was lower, ΔPaCO2 was smaller, and ΔPaO2 was greater in the high leptin group than in the low leptin group. In multiple regression analysis, leptin was negatively associated with preoperative PaO2 (estimate coefficient = -0.147; p = 0.023). In logistic regression analysis, leptin was associated with improved ΔPaO2 (odds ratio [OR] = 1.104; p = 0.0138) and ΔPaCO2 (OR = 0.968; p = 0.0334). Leptin appears to have dual effects related to perioperative gas exchange in obese patients undergoing bariatric surgery. It is associated with worse preoperative oxygenation but improved respiratory function after surgery.

Procalcitonin impact analysis, respiratory function and blood gas analysis on Xiaoqinglong decoction combined with non-invasive ventilation in treatment of AECOPD patients

To observe the effect of Xiaoqinglong decoction combined with noninvasive ventilation on procalcitonin (PCT), blood gas analysis and respiratory functions in acute exacerbation of chronic obstructive pulmonary disease in the elderly (AECOPD), and investigate its correlation and clinical significance. Eighty-four elderly AECOPD patients with respiratory failure in our hospital from January 2015 to October 2017, were randomly divided into control group and observation group, 42 cases in each group. The control group received western medicine combined with noninvasive ventilator therapy, and the patients in observation group additionally received Xiaoqinglong decoction on the basis of the treatment in control group. Both groups were treated for 2 weeks. The clinical effects of two groups were observed and their PCT, blood gas analysis outcomes [arterial oxygen partial pressure (PaO₂), arterial partial pressure of carbon dioxide (PaCO₂), respiratory function, forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), FEV1/FVC], TCM syndrome score and other indexes and adverse reactions were compared before and after treatment. The total efficiency was 95.24% (40/42) in observation group, higher than 76.19% (32/42) in control group, with statistically significant difference (P<0.05). There were no statistically significant differences in PCT, PaO₂, PaCO₂, FVC, FEV1/FVC, FEV1, and TCM syndrome scores between two groups before treatment. But after treatment, PCT and PaCO₂ levels in the observation group were lower and PaO₂, FVC, FEV1/FVC, FEV1 levels was higher than those in the control group (P<0.05); TCM syndrome scores were lower than those in the control group (P<0.05); both groups had no obvious adverse reactions. The results showed that Xiaoqinglong decoction combined with noninvasive ventilator could significantly reduce the procalcitonin level, effectively improve the respiratory function and blood gas analysis indexes, and significantly reduce the clinical symptoms in AECOPD patients, so it is worthy of promotion.

Effect of ischemic preconditioning combined with ?7 nAchR agonists on limb ischemia-reperfusion lung injury in rat

Objective: To investigate the effect of ischemic preconditioning combined with α7 nAchR agonists on limb ischemia-reperfusion lung injury in rats. Methods: Fifty healthy male Sprague-Dawley rats weighing 230-280 g were randomly divided into 5 groups: sham operation group (S, also means the control group), model group(M), model and ischemic preconditioning (IP) group, model and α7 nAchR agonists group (PNU) and model and united treatment (U) group. The model of lung injury was induced by 3 h of ischemia and 3 h of reperfusion. The arterial blood was collected at 3 h- reperfusion for blood gas analysis; The lung tissues were collected for determination of Pulmonary coefficient, malondialdehyde (MDA) content, superoxide dismutase (SOD) activity and lung tissue inflammatory cytokines (IL-6 and TNF-a). The pathological changes of lung tissues were observed under light microscope, and the pathological score of lung tissue was conducted. Results: Compared with S group, the PaO2, pH and the activity of SOD in lung tissue of M group at 3 h reperfusion were significantly decreased, Pulmonary coefficient, MDA,IL-6, TNF-a and pulmonary pathological score of lung tissue were significantly increased (P<0.05), the difference of PaCO2 was not statistically significant (P>0.05). Compared with M group, arterial PaO2and lung SOD activity of IP group, PNU Group, U group at 3 h-reperfusion decreased, while Pulmonary coefficient, lung group, MDA,IL-6, TNF-a and pulmonary pathological score of lung tissue were significantly increased (P<0.05), there was no statistically significant difference in pH and PaCO2 between the two groups (P>0.05). Compared with IP group and PNU group, PaO2 and SOD activity of lung tissue decreased in U group at 3 h reperfusion, Pulmonary coefficient, MDA, IL-6, TNF-a, pulmonary pathology scores of lung tissue increased (P<0.05). There was no significant difference in PH and PaCO2 between the two groups (P>0.05). Conclusion: Ischemic preconditioning and α7 nAchR agonists can attenuate limb ischemia-reperfusion lung injury in rat to a certain extent, and the combined effect of the two is better than the separate application.

Predictive capability of End Tidal carbon dioxide and its correlation with arterial carbon dioxide in mechanically ventilated children

Back ground:End-tidal carbon dioxide (ETCO2) is a surrogate, non-invasive measurement of arterial carbon dioxide (PaCO2); however, its clinical applicability in the intensive care unit setting remains unclear in pediatric population. Objectives:This study aims at assessing the effect of severity of lung disease and correlation between ETCO2 and PaCO2 Materials and methods: This was a prospective, nonrandomised study carried in pediatric intensive care unit of a tertiary care unit on 104 children requiring mechanical ventilation. Simultaneous ETCO2 and PaCO2 recording were taken, data on ventilator parameters recorded. Severity of lung disease was estimated by alveolar- arteriolar oxygen gradient, ventilation index and PaO2/FiO2 ratio. The PaCO2 and ETCO2 difference and its variability were studied. Results:208 samples were analysed where the mean PaCO2 value 28.9±9.7 mmhg was higher than mean ETCO2 value of 27.8±9.6 mmHg. The mean difference between PACO2 and ETCO2 was 1.6±3.23 mmHg. There was significant level of correlation between PACO2 and ETCO2 ( r=0.941, r2 = 0.886 , 95% CI= 0.95-0.97) for mild to moderate lung disease than severe lung disease. Systemic diseases, Ventilator index and alveolar arterial oxygen gradient did not have any significant correlation with the PACO2 and ETCO2 difference in our study. Conclusion: Significant correlation was found between the PaCO2 and ETCO2 value irrespective of the disease conditionand ETCO2 can be validated to predict PACO2.

Effects of active abdominal compression-decompression CPR on oxygen metabolism and prognosis in patients with cardiac arrest

To analyze the effect of active abdominal compression-decompression cardiopulmonary resuscitation (AACD-CPR) and standard cardiopulmonary resuscitation (STD-CPR) on oxygen metabolism and prognosis of patient with cardiac arrest (CA), and to evaluate the treatment effect of AACD-CPR. Patients with CA, CA time less than 30 minutes, and without STD-CPR and AACD-CPR contraindications admitted to the Zhengzhou People's Hospital from October 1st 2015 to May 31st 2017 were enrolled. The patients were divided into STD-CPR group and AACD-CPR group according to random number table. All patients were given the same rescue measures, if required to give defibrillation; STD-CPR group was operated according to the 2015 American Heart Association (AHA) CPR guidelines; AACD-CPR group was recovered using abdominal lifting and compression cardiopulmonary resuscitation instrument. The oxygen metabolism, hemodynamic, arterial blood gas and prognostic indicators were recorded in the two groups during the resuscitation. A total of 69 cases, with STD-CPR group of 34 cases and AACD-CPR group of 35 cases were enrolled finally. (1) The oxygen metabolism: during the recovery, compared with STD-CPR group, arterial blood oxygen content (CaO2), arterial-venous oxygen content difference (avDO2), the oxygen carrying capacity (DO2), oxygen consumption (VO2) in AACD-CPR group were significantly increased [CaO2 (mL/L): 156±15 vs. 142±19, avDO2 (mL/L): 83±14 vs. 73±13, DO2 (mL/min): 248±51 vs. 208±54, VO2 (mL/min): 134±29 vs. 118±32, all P < 0.05], but there were no significant differences in cardiac output (CO) and mixed venous oxygen content (CvO2). (2) Hemodynamic and arterial blood gas: there were no significant differences in the base values of the heart rate (HR), mean arterial pressure (MAP), pH value, pulse oxygen saturation (SpO2), arterial oxygen pressure (PaO2), arterial partial pressure of carbon dioxide (PaCO2), and blood lactate (Lac) between two groups. In the recovery process, MAP, pH value, SpO2, PaO2 of two groups were increased, while PaCO2 and Lac were decreased. Except MAP of STD-CPR group was slightly higher than AACD-CPR group, the change tendency of AACD-CPR group was more obvious in each index obviously [pH value difference: 0.10±0.15 vs. 0.02±0.13, SpO2 difference: 0.311±0.255 vs. 0.159±0.232, PaO2 difference (mmHg, 1 mmHg = 0.133 kPa): 12.96±21.84 vs. 3.01±13.56, PaCO2 difference (mmHg): -9.91±11.17 vs. -3.52±13.87, Lac value difference (mmol/L): -0.64±0.61 vs. -0.31±0.58, all P < 0.05]. (3) Prognosis: compared with STD-CPR group, the restoration of spontaneous circulation (ROSC) rate in AACD-CPR group was slightly increased (22.9% vs. 8.8%, P > 0.05), but the ROSC time in AACD-CPR group was significantly shortened (minutes: 9.59±2.67 vs. 11.83±3.05, P < 0.01), nerve function defect score (NDS) was significantly decreased at 1, 2 weeks (26.45±6.42 vs. 30.73±7.38, 19.25±6.27 vs. 22.64±5.63, both P < 0.05), and the 2-week survival was slightly increased (17.1% vs. 5.9%, P > 0.05). AACD-CPR is similar to STD-CPR in improving hemodynamics of CA patients, but has advantage in the blood oxygen supply for tissues and organs, and the neurological function prognosis is better.

High-pressure versus low-pressure home non-invasive positive pressure ventilation with built-in software in patients with stable hypercapnic COPD: a pilot study

High-pressure non-invasive positive pressure ventilation (NPPV) is a new strategy targeted at maximally reducing arterial carbon dioxide. However, high inspiratory positive airway pressure (IPAP) might cause respiratory adverse events likely to diminish the benefit of NPPV. In the setting of ventilatory support, monitoring NPPV efficacy and resolving problems promptly are critical. This study assessed the treatment effect of high and low-pressure NPPV in chronic hypercapnic COPD using home ventilator with built-in software. In this pilot study, we investigated 34 patients using NPPV for 3 months. 13 patients used high-pressure ventilation and 21 patients used low-pressure ventilation. The primary outcome was daytime partial pressure of arterial blood carbon dioxide (PaCO2). There were no between-group differences in daytime PaCO2 and FEV1, but a trend favouring high-pressure NPPV was observed. Significant between-group differences were found in the transition dyspnoea index (TDI) (high-pressure, 1.69 ± 1.75, versus low-pressure, −0.04 ± 2.71, p = 0.044). No differences were found in usage time, leakage, health-related quality of life, spirometry, or 6-minute walk test. High-pressure NPPV with built-in software monitoring in patients with chronic hypercapnic COPD is associated with improvement in TDI scores and a positive trend in favour of high-pressure NPPV for improving PaCO2 is observed.

Abstract 21060: The Association Between Post-Resusciation Cerebral Oxygenation and Survival With Favorable Neurological Outcomes: A Multicenter Study

Background: Cerebral ischemia/reperfusion injury in the post-resuscitation period contributes to morbidity and mortality following cardiac arrest (CA). Cerebral oximetry is a non-invasive system that uses near infrared spectroscopy to measure regional cerebral oxygenation level (rSO2) in the frontal lobe of the brain. Studies have shown that post-resuscitation rSO2 may be associated with survival and neurological outcomes in out-of-hospital cardiac arrest patients, however no studies have examined this in in-hospital cardiac arrest (IHCA) patients. Hypothesis: rSO2 changes following return of spontaneous circulation (ROSC) after IHCA are associated with survival with favorable neurological outcomes. Methods: A multi-site prospective study of consecutive day-time IHCA patients admitted to the ICU after ROSC at 7 sites. Continuous rSO2 monitoring (Equanox 7600, Nonin Medical, MN, USA) was applied for 48 hours after ROSC using a forehead sensor. Mean rSO2 was calculated hourly between 1-6 hrs. and at 6, 12, 18, 24, 48 hr. intervals. Demographic and data pertaining to possible confounding variables for rSO2 and survival with favorable neurological outcomes (cerebral performance scale [CPC] 1-2) vs death or severe neurological injury (CPC 3-5) at hospital discharge were collected. Results: Among 87 studied patients, 26 (29.9%) achieved CPC1-2. There were no differences in age, Charlson comorbidity index, APACHE II scores, and resuscitation duration, however, CPC 1-2 was higher in men vs. women (36.5% vs. 12.5%, p = 0.036). A significant difference in mean rSO2 was observed during hours 1-2 after ROSC in CPC 1-2 vs CPC3-5 (73.08 vs. 66.59, p = 0.031) but not at other time points. There were no differences in mean arterial pressure, PaO2, PaCO2, and hemoglobin levels, however subjects with CPC 1-2 had lower glucose (154.4mg/dL vs. 202.8mg/dL, p = 0.0054), lactate level (4.11 mmol/dL vs. 6.39 mmol/dL, p = 0.030), and higher Glasgow coma scale (9.42 vs. 5.96, p = 0.0026) within the first 24 hours. Conclusions: Changes in rSO2 as measured by cerebral oximetry in the first two hours after ROSC may predict survival with neurological outcomes after resuscitation following IHCA.

Comparison of the effect of two different ways of cardiopulmonary resuscitation during cardiac arrest

Objective To compare the effect of two different types of cardiopulmonary resuscitation(CPR) in cardiac arrest. Methods 150 patients with cardiac arrest were selected.The patients were divided into two groups according to the random number table method, each group in 75cases.The patients in the control group were treated with CPR.The patients in the observation group were treated with CPR machine.The body temperature, hemoglobin concentration, hematocrit, arterial blood gas analysis and resuscitation were compared between the two groups after 10min and 30min. Results There were no statistically significant differences in body temperature, hemoglobin and hematocrit between the control group and the observation group at 10min and 30min after CPR (t10min=1.44, 2.01, 1.23, t30min=1.69, 1.81, 1.02, all P>0.05). There were no statistically significant differences in PaCO2 between the two groups at 10 min and 30 min after resuscitation (t=1.54, 1.02, all P>0.05). The arterial blood pH[(7.02±0.14)], PaO2[(16.29±4.38)kPa], HCO3- [(5.66±1.73)kPa]and SaO2[(0.84±0.05)%]of the control group recovered 30 min were significantly lower than recovered 10 min (t=7.14, 6.55, 6.20, 7.03, all P<0.05). The arterial blood pH[(7.11±0.1)], PaO2[(18.36±4.55)kPa], HCO3- [(6.34±2.15)kPa], SaO2[(0.86±0.04)%]of the observation group recovered 30 min were significantly lower than recovered 10 min (t=6.75, 6.21, 6.01, 6.60, all P<0.05). The arterial blood pH, PaO2, HCO3- and SaO2 of the observation group were significantly higher than those in the control group at 10 min and 30 min, the differences were statistically significant (t10min=6.03, 7.34, 7.88, 6.10, t30min=6.21, 8.20, 7.10, 6.11, all P<0.05). The effective rate of CPR in the observation group was 69.33%, which was significantly higher than 46.67% in the control group, the difference was statistically significant (χ2=9.34, P<0.05). Conclusion Compared with artificial heart and lung resuscitation, CPR machine is more effective for patients with heartbeat respiratory arrest.It is more effective in cycling support and can improve the efficacy of CPR and is worthy of clinical application. Key words: Heartbeat respiratory arrest; Cardiopulmonary resuscitation; Cardiopulmonary resuscitation machine

Targeting low- or high-normal Carbon dioxide, Oxygen, and Mean arterial pressure After Cardiac Arrest and REsuscitation: study protocol for a randomized pilot trial

BackgroundArterial carbon dioxide tension (PaCO2), oxygen tension (PaO2), and mean arterial pressure (MAP) are modifiable factors that affect cerebral blood flow (CBF), cerebral oxygen delivery, and potentially the course of brain injury after cardiac arrest. No evidence regarding optimal treatment targets exists.MethodsThe Carbon dioxide, Oxygen, and Mean arterial pressure After Cardiac Arrest and REsuscitation (COMACARE) trial is a pilot multi-center randomized controlled trial (RCT) assessing the feasibility of targeting low- or high-normal PaCO2, PaO2, and MAP in comatose, mechanically ventilated patients after out-of-hospital cardiac arrest (OHCA), as well as its effect on brain injury markers. Using a 23 factorial design, participants are randomized upon admission to an intensive care unit into one of eight groups with various combinations of PaCO2, PaO2, and MAP target levels for 36 h after admission.The primary outcome is neuron-specific enolase (NSE) serum concentration at 48 h after cardiac arrest. The main feasibility outcome is the between-group differences in PaCO2, PaO2, and MAP during the 36 h after ICU admission. Secondary outcomes include serum concentrations of NSE, S100 protein, and cardiac troponin at 24, 48, and 72 h after cardiac arrest; cerebral oxygenation, measured with near-infrared spectroscopy (NIRS); potential differences in epileptic activity, monitored via continuous electroencephalogram (EEG); and neurological outcomes at six months after cardiac arrest.DiscussionThe trial began in March 2016 and participant recruitment has begun in all seven study sites as of March 2017. Currently, 115 of the total of 120 patients have been included. When completed, the results of this trial will provide preliminary clinical evidence regarding the feasibility of targeting low- or high-normal PaCO2, PaO2, and MAP values and its effect on developing brain injury, brain oxygenation, and epileptic seizures after cardiac arrest. The results of this trial will be used to evaluate whether a larger RCT on this subject is justified.Trial registrationClinicalTrials.gov, NCT02698917. Registered on 26 January 2016.

High-flow oxygen via nasal cannulae in patients with acute hypoxemic respiratory failure: a systematic review and meta-analysis

BackgroundWe performed a systematic review and meta-analysis to evaluate the efficacy and safety of high-flow oxygen via nasal cannulae (HFNC) compared to non-invasive ventilation (NIV) and/or standard oxygen in patients with acute, hypoxemic respiratory failure.MethodsWe reviewed randomized controlled trials from CENTRAL, EMBASE, MEDLINE, Scopus and the International Clinical Trials Registry Platform (inception to February 2016), conference proceedings, and relevant article reference lists. Two reviewers independently screened and extracted trial-level data from trials investigating HFNC in patients with acute, hypoxemic respiratory failure. Internal validity was assessed in duplicate using the Cochrane Risk of Bias tool. The strength of evidence was assessed in duplicate using the Grading of Recommendations Assessment, Development and Evaluation framework. Our primary outcome was mortality. Secondary outcomes included dyspnea, PaO2:FiO2 ratio, PaCO2, and pH. Safety outcomes included respiratory arrest, intubation, delirium, and skin breakdown.ResultsFrom 2023 screened citations, we identified seven trials (1771 patients) meeting inclusion criteria. All trials were at high risk of bias due to lack of blinding. There was no evidence for a mortality difference in patients receiving HFNC vs. NIV and/or standard oxygen (RR 1.01, 95% CI 0.69 to 1.48, I2 = 63%, five trials, 1629 patients). In subgroup analyses of HFNC compared to NIV or standard oxygen individually, mortality differences were not observed. Measures of patient tolerability were heterogeneous. The PaO2:FiO2 ratio at 6–12 h was significantly lower in patients receiving oxygen via HFNC compared to NIV or standard oxygen for hypoxemic respiratory failure (MD − 53.34, 95% CI − 71.95 to − 34.72, I2 = 61%, 1143 patients). There were no differences in pH, PaCO2, or rates of intubation or cardio-respiratory arrest. Delirium and skin breakdown were infrequently reported in included trials.ConclusionsIn patients with acute hypoxemic respiratory failure HFNC was not associated with a difference in mortality compared to NIV or standard oxygen. Secondary outcomes including dyspnea, tolerance, and safety were not systematically reported. Residual heterogeneity and variable reporting of secondary outcomes limit the conclusions that can be made in this review. Prospective trials designed to evaluate the efficacy and safety of HFNC in patients with acute hypoxemic respiratory failure are required.

Research on the effectiveness between high flow nasal oxygen cannula and non-rebreather oxygen face mask in post-extubation patients

Objective To compare the clinical effects of high flow nasal cannula (HFNC) and non-rebreathing oxygen face mask(NRB) in post-extubation patients. Methods 88 critically ill patients with machinery ventilations were divided into HFNC group and NRB group randomly. Blood gas analysis and hemodynamic parameters were assessed 1 hour prior to extubation and 6 hours after extubation. The primary clinical outcomes measured were ventilation-free days, re-intubation patient numbers, length of stay in ICU(Intensive Care Unite) , total duration of hospitalization and mortality. The scant of breath degree and comfortableness of patient were recorded according to the Visual analogue scale. The measurement data were described by mean±standard deviation (±s) and analyzed with t test, enumeration data were described by number of cases and composition ratio and analyzed with χ2test, P<0.05 was considered to have statistical difference. Results There was no significant difference in clinical features between the two groups, The oxygenation index of HFNC group is significantly higher than that of NRB group after extubation [(251.4±43.9) vs.(201.7±60.7), P=0.037)]. There were more ventilator-free days in the HFNC group than NRB group [(4.2± 2.1) vs.(3.4±2.8), P=0.037)] and fewer patients required re-intubation(P=0.028). The rate of ventilator associated pneumonia is also lower than NRB group(P=0.024). The patients’ scant of breath feeling were obviously allevated comparing with the NRB group [(2.9±1.1) vs.(3.7±1.8), P=0.042)]. The oxygenation index of NRB group significantly decreased after extubation[(242.9±68.4vs.201.7±60.7 P=0.048)]. The two groups demonstrated similar hemodynamic patterns before and after extubation. And there were no statistically significant clinical differences in PaCO2, length of ICU stay, total duration of hospitalization or mortality. Conclusions Compared with NRB, HFNC is a more safe and effective clinical tool in the prevention and treatment of critical adult patients with extubation failure. Key words: High flow nasal cannula (HFNC); Non-rebreathing oxygen face mask (NRB); Post-extubation respiratory failure; Mechanical ventilation; Extubation; Curative effect

Intraoperative acidosis and hypercapnia during thoracoscopic repair of congenital diaphragmatic hernia and esophageal atresia/tracheoesophageal fistula

Intraoperative hypercapnia and acidosis have been associated with thoracoscopic repair of both congenital diaphragmatic hernia and esophageal atresia/tracheoesophageal fistula. The aim of the present study was to investigate whether thoracoscopic repair of congenital diaphragmatic hernia or esophageal atresia/tracheoesophageal fistula was associated with acidosis and hypercapnia in a large group of neonates, and to analyze the effects of acidosis and hypercapnia on early postoperative outcomes. We reviewed the charts of neonates who underwent open or thoracoscopic congenital diaphragmatic hernia or esophageal atresia/tracheoesophageal fistula repair (2004-2014). Patients with available intraoperative arterial gas values were included. Data (PaCO2 : mm Hg) were compared using paired/unpaired tests and are reported as difference [95% confidence interval]. Congenital diaphragmatic hernia: 187 neonates underwent open (n=153) or thoracoscopic (n=34) repair. Intraoperative arterial gas values were recorded in 96 open and in 23 thoracoscopic operations. Both groups had similar preoperative pH and PaCO2 , and developed intraoperative acidosis (open -0.08 [-0.11, -0.05] P<.001, thoracoscopic -0.14 [-0.24, -0.04] P=.01) and hypercapnia (open: 7.8 [3.2, 12.4], P=.002; thoracoscopic: 20.2 [-2.5, 43, P=.07). Intraoperatively, neonates undergoing thoracoscopic repair developed lower pH than those having open surgery (-0.06 [-0.01, -0.10] P=.018), but maintained similar levels of PaCO2 (-4.0 [-9.0, 4.4] P=.39). Esophageal atresia/tracheoesophageal fistula: 205 neonates underwent open (n=180) or thoracoscopic (n=25) repair. Intraoperative arterial gas values were recorded in 62 open and in 14 thoracoscopic operations. Both groups had similar preoperative pH and PaCO2 , and developed intraoperative acidosis (open: -0.09 [-0.14, -0.04], P<.001; thoracoscopic: 0.21 [-0.28, -0.14], P<.001) and hypercapnia (open: 9.2 [2.6, 15.7] P=.008; thoracoscopic: 15.2 [1.6, 28.7], P=.03). Intraoperatively, neonates undergoing thoracoscopic repair developed lower pH than those having open surgery (difference 0.08 [0.01, 0.15], P=.02) but maintained similar levels of PaCO2 (difference -1 [-9, 3], P=.35). Neonates undergoing operative repair of congenital diaphragmatic hernia and esophageal atresia/tracheoesophageal fistula develop intraoperative acidosis and hypercapnia, regardless of the approach used. However, this phenomenon is more severe during thoracoscopic repair. Novel modalities to reduce intraoperative gas derangements, particularly during thoracoscopic repair, need to be established.