Gas Analysis Parameters Research Articles

Can the CT by-product Time to threshold be a prognostic factor in patients with acute pulmonary embolism?

Bolus tracking is applied in computed tomography pulmonary angiography. The time that it takes for contrast to reach a predefined threshold in the pulmonary artery is called time to threshold (TTT). Our purpose was to analyse possible associations between TTT and circulatory state and prognosis in patients with acute pulmonary embolism (PE). In a single-centre, retrospective study 138 patients with PE and contrast administration via peripheral venous line were included. Clinical parameters of circulatory state were arterial pH, systolic blood pressure, heart rate, sPESI score, Wells score and GENEVA score. Survival was defined as surviving the following 30 days after the PE diagnosis. Time to threshold was only weakly correlated with Fi02 (r = 0.26, P = 0.04), pH (r = -0.22, P = 0.009), venous base excess (r = -0.18, P = 0.04) and venous lactate (r = 0.21, P = 0.01). TTT did not correlate with clinical parameters/scores and mortality. There were weak associations between TTT and blood gas analysis parameters. There were no associations with clinically relevant prognosis scores and overall survival. Therefore, albeit TTT is an easily assessable parameter of CTPA, the potential use in clinical routine is limited for prognosis stratification in patients with PE.

The effect of clamped and unclamped umbilical cord samples on blood gas analysis

PurposeDelayed cord clamping for at least 60 s is recommended to improve neonatal outcomes. The aim of this study is to evaluate whether there are differences in cord BGA between samples collected after double clamping the cord or without clamping the cord, when blood collection occurs within 60 s from birth in both groups.MethodsA cross-sectional study was carried out, collecting data from 6884 high-risk women who were divided into two groups based on the method of cord sampling (clamped vs unclamped).ResultsThere were significant decrease in pH and BE values into unclamped group compared with the clamped group. This difference remained significant when considering pathological blood gas analysis parameters, with a higher percentage of pathological pH or BE values in the unclamped group.ConclusionSamples from the unclamped cord alter the acid–base parameters compared to collection from the clamped cord; however, this difference does not appear to be of clinical relevance. Findings could be due to the large sample size, which allowed to achieve a high power and to investigate very small numerical changes between groups, leading to a statistically significant difference in pH and BE between samples even when we could not appreciate any clinical relevant difference of pH or BE between groups. When blood gas analysis is indicated, the priority should be given to the timing of blood collection to allow reliable results, to assess newborns status at birth and intervene when needed.

Short-term outcome and characteristics of critical care for nontrauma patients in the emergency department.

Emergency medical care for critically ill nontrauma patients (CINT) varies between different emergency departments (ED) and healthcare systems, while resuscitation of trauma patients is always performed within the ED. In many ED CINT are treated and stabilized while in many German smaller hospitals CINT are transferred directly to the intensive care unit (ICU) without performing critical care measures in the ED. Little is known about the resuscitation room management of CINT regarding patient characteristics and outcome although bigger hospitals perform ED resuscitation of CINT in routine care. Against this background we conducted this retrospective analysis of CINT treated by an ED resuscitation room concept in aGerman 756 bed teaching hospital. The collective of CINT treated within the ED resuscitation room (1 October 2018 to 31 March 2019) was analyzed after ethical approval. After each resuscitation room operation, the team leader filled out astandardized paper-based questionnaire and qualified the patient as aresuscitation room patient this way. Only patients who underwent invasive procedures and were admitted to ICU or died in the ED were included. Patient characteristics, performed critical care measures, short-term outcomes and the comparison of admission characteristics between survivors and non-survivors were evaluated. Additionally, the accordance of ED admission diagnoses and discharge diagnoses were analyzed. Overall, 243 of 19,854 ED patients (1.22%) were treated in the resuscitation room. After exclusion of trauma patients, 193 (0.97%) CINT were included. Overall mortality was 29% (n = 56), 24‑h mortality was 13% (n = 25). Patient characteristics (vital signs, blood gas analysis) differed significantly between survivors and nonsurvivors except for respiratory rate and pain scale. An excerpt of conducted resuscitation room measures was as follows: arterial line n = 78 (40%); noninvasive ventilation n = 60 (31%); endotracheal intubation n = 56 (29%); cardiopulmonary resuscitation n = 19 (10%), central venous line n = 8 (4%). The number of conducted measures differed between survivors and nonsurvivors (median and interquartile range, IQR): 4(IQR2) vs. 4(IQR3) p = 0.0453. The length of ED stay was 148.2 ± 202.7 min until the patient was admitted to an ICU or died within the ED. ED admission diagnoses matched with hospital discharge diagnoses in 78%. The observed mortality was high and was comparable to patient collectives with septic shock. Nonsurvivors showed significantly more impaired vital parameters and blood gas analysis parameters. Vital parameters together with blood gas analysis might enable ED risk stratification of CINT. Resuscitation room management enables immediate stabilization and diagnostic work-up of CINT even when no ICU bed is available. Furthermore, optimal allocation to specialized ICUs can probably be enabled more accurately after afirst diagnostic work-up; however, although afirst diagnostic work-up including laboratory tests and computed tomography in many cases was performed, ED admission and hospital discharge diagnoses matched only in 78%.

Determinants of response to hypercapnia and to progressive and transient hypoxia in obstructive sleep apnea patients.

The knowledge regarding the control of breathing during wakefulness in patients affected by obstructive sleep apnea (OSAS) is still challenging. The aim of this study is firstly to analyze hypoxic and hypercapnic ventilatory response in OSA patients in comparison to controls and secondly, to investigate correlations between chemosensivity and both lung function tests, such as arterial blood gas analysis and spirometric parameters, and clinical characteristics, such as age and BMI. Seventeen never treated OSA patients (16M; 53±13.2 years; BMI=34.5±8.1; AHI=45±14.7) underwent nocturnal cardiopulmonary monitoring test, complete lung function tests (spirometry, lung volumes and arterial blood gas analysis on room air). Read's rebreathing test was used to evaluate hypercapnic ventilatory response (HVR<inf>CO2</inf>); hypoxic ventilatory response (HVR<inf>O2</inf>) was studied through progressive and transient methods. The response was expressed in terms of slope of linear regression for HVR<inf>CO2</inf> and of hyperbolic curve for HVR<inf>O2</inf> between minute ventilation (VE) or mean inspiratory flow (VT/Ti) and PetCO<inf>2</inf> or PetO<inf>2</inf>. The OSA group showed increased transient, but not progressive, HVR<inf>O2</inf> and a lower HVR<inf>CO2</inf>. A lower HVR<inf>CO2</inf> was predicted by greater values of BMI (P<0.01). Progressive HVR<inf>O2</inf> increased with age and lower FEV<inf>1</inf>/VC, while transient HVR<inf>O2</inf> (P<0.05) was inversely correlated with the nocturnal lowest SaO<inf>2</inf> (P<0.01). Nocturnal intermittent hypoxic stimuli increases daytime glomic reactivity to transient hypoxia, while BMI is the main independent determinants of the bulbar response to hypercapnia in normocapnic OSAS patients.

Effects of mechanical ventilation with different tidal volumes on right ventricular hemodynamics in acute respiratory distress syndrome rats

To explore the effect of different tidal volumes (VT) on the hemodynamics of right heart in acute respiratory distress syndrome (ARDS) rats induced by oleic acid (OA). Sixty adult male Sprague-Dawley (SD) rats were divided into control group (n = 20), ARDS model group (n = 20), low VT (LVT) group (n = 10) and high VT (HVT) group (n = 10) by random number table. ARDS model was reproduced by injecting OA 0.15 mL/kg through a jugular vein. The control group was given the same amount of normal saline. The success of modeling was judged by the oxygenation index (PaO2/FiO2) 2 hours after modeling, at the same time, the lung tissues were collected, the wet/dry weight (W/D) ratio was determined, and the lung histopathological changes were measured by lung injury score. The rats in the LVT group and HVT group were given mechanical ventilation with VT of 6 mL/kg or 20 mL/kg for 4 hours, respectively at 2 hours after modeling. The rats in the control group and the ARDS model group maintained spontaneous breathing. After mechanical ventilation for 4 hours, the heart rate (HR), right ventricular systolic pressure (RVSP), the maximum rate of rising of right ventricular pressure (dp/dt max), and the blood pressure (BP) were measured. Meanwhile, arterial blood samples were collected for blood gas analysis, including pH value, arterial partial pressure of oxygen (PaO2), arterial partial pressure of carbon dioxide (PaCO2) and PaO2/FiO2. The rats in the ARDS model group showed symptoms of respiratory distress 1 hour after modeling, and the lung tissue samples showed obvious patchy bleeding 2 hours after modeling, while the control group showed no such changes. The PaO2/FiO2 in the ARDS model group was significantly lower than that in the control group [mmHg (1 mmHg = 0.133 kPa): 294.3±5.9 vs. 459.0±4.4, P < 0.01], and the lung W/D ratio and lung injury score were significantly higher (lung W/D ratio: 8.24±0.25 vs. 4.48±0.13, lung injury score: 0.60±0.03 vs. 0.12±0.02, both P < 0.01). It indicated that ARDS model was successfully reproduced. The arterial blood gas analysis and hemodynamic parameters of the ARDS model group were significantly worse than those of the control group. After 4-hour mechanical ventilation, the blood gas parameters of the LVT group were better than those of the ARDS model group and the HVT group [pH value: 7.36±0.02 vs. 7.24±0.02, 7.13±0.01; PaO2 (mmHg): 92.4±2.1 vs. 61.8±2.3, 76.6±2.2; PaCO2 (mmHg): 49.6±1.7 vs. 61.8±1.8, 33.6±1.3; PaO2/FiO2 (mmHg): 440.0±10.2 vs. 274.3±21.4, 364.7±10.5; all P < 0.05]. HR, BP and dp/dt max in the LVT group were significantly higher than those in the ARDS model group and the HVT group [HR (bpm): 346.9±5.4 vs. 302.3±10.1, 265.5±12.2; BP (mmHg): 125.4±2.2 vs. 110.0±2.5, 89.2±2.8; dp/dt max (mmHg/s): 1 393.3±30.3 vs. 1 236.4±20.5, 896.1±19.5; all P < 0.05], and RVSP was significantly lower than that in the ARDS model group and the HVT group (mmHg: 31.3±0.4 vs. 34.0±1.0, 38.8±0.9, both P < 0.05). Mechanical ventilation with low VT can improve the hemodynamic parameters of the right ventricle and protect the function of the right heart in ARDS rats.

Prone and Lateral Positioning in Spontaneously Breathing Patients With COVID-19 Pneumonia Undergoing Noninvasive Helmet CPAP Treatment

Prone and Lateral Positioning in Spontaneously Breathing Patients With COVID-19 Pneumonia Undergoing Noninvasive Helmet CPAP Treatment

Correlation Between Serum Levels of 25-Hydroxyvitamin D and Severity of Community-Acquired Pneumonia in Hospitalized Patients Assessed by Pneumonia Severity Index: An Observational Descriptive Study.

IntroductionPneumonia severity index (PSI) is a prognostic index used for estimating the possibility of death due to community-acquired pneumonia. Vitamin D is a fat-soluble vitamin, essential for calcium and phosphate homeostasis. Vitamin D also has antimicrobial properties and according to recent studies, its deficiency may be correlated to an increased frequency of respiratory infections. The serum concentration of 25-hydroxyvitamin D (25(OH)D) is the best vitamin D status index reflecting vitamin D produced in the skin and offered from food and dietary supplements.MethodsThe study involved patients, who fulfilled the criteria of community-acquired pneumonia. The exclusion criteria were: patients <18 years old, severely immunocompromised patients, patients with tuberculosis, patients with malabsorption disorders, nursing home residents, patients with a history of malignancy, chronic renal or liver disease, patients with congestive health failure or cerebrovascular disease, and patients receiving vitamin D as a supplement. The following parameters, recorded on admission, were evaluated: age, sex, co-morbidity, residence in a nursing home, duration of symptoms, clinical symptoms, confusion, blood gas analysis, chest radiograph (pleural effusion), and laboratory parameters. The patients were classified in risk classes according to the PSI. Blood samples were collected within the first 48 hours of hospitalization. The serum levels of 25-hydroxyvitamin D were determined by electrochemiluminescence binding assay in Roche Cobas 601 immunoassay analyzer and mean serum levels of 25-hydroxyvitamin D in each risk class were calculated. For statistical analysis, the statistical program SPSS for Windows version 17.0 (Statistical Package for the Social Sciences, SPSS Inc., Chicago, IL) was used.ResultsA total of 46 patients, 28 males and 18 females, with a mean age of 71.5±17.57 years, hospitalized with community-acquired pneumonia, were included. Sixteen patients (35%) had a severe deficiency, with 25(OH)D levels <10 ng/ml, 17 patients (37%) had moderate deficiency with 25(OH)D levels between 10-20 ng/ml, and 13 patients (28%) had insufficiency with 25(OH)D levels between 20-29 ng/ml. According to the PSI, four (8.7%) patients with a mean age of 53.75±15.43 years were classified as risk class I, 10 (21.7%) patients with a mean age of 54.7±14.82 years as class II, 10 (21.7%) patients with a mean age of 68.41±3.96 years as class III, 17 (37%) patients with a mean age of 84.82±9.73 years as class IV, and five (10.9%) patients with a mean age of 80.2±9.41 years as class V. The mean levels of 25(OH)D were 19.11±11.24 ng/ml in class I, 16.81±8.94 ng/ml in class II, 16.65±9.18 ng/ml in class III, 14.76±10.22 ng/ml in class IV, and 7.49±4.41 ng/ml in class V. There was a positive correlation between low levels of 25(OH)D and the pneumonia severity and statistically significant difference between the mean levels of 25(OH)D in class V (7.49±4.41 ng/ml) compared to overall mean levels in classes I, II, III and IV (16.15±9.49 ng/ml), with p<0.05.ConclusionsAccording to our results, there was a positive association between low levels of 25-hydroxyvitamin D and community-acquired pneumonia severity assessed by PSI. The determination of 25-hydroxyvitamin-D status, mostly in patients >60 years old, may prevent severe community-acquired pneumonia.

N-BiPAP vs n-CPAP in term neonate with respiratory distress syndrome

BackgroundNon-invasive respiratory ventilation has greatly improved the evolution of respiratory distress in neonates, especially for preterm infants, but few studies have investigated the use of non-invasive ventilation (NIV) in term infants. It is useful for neonatologists and nurses to identify the optimal ventilation strategy in terms of effectiveness for this group of newborns.The aim of our study was to investigate what type of respiratory support between nasal Continuous Positive Airway Pressure (nCPAP) or nasal Biphasic Positive Airway Pressure (nBiPAP) is more effective in term neonates with RDS. MethodsOur study was a retrospective observational study of 78 full term neonates who were admitted to the NICU at S. Bambino Hospital from December 2015 to December 2016 for respiratory distress at birth. All patients underwent non-invasive ventilation by nCPAP or nBiPAP were included. Oxygen saturations and vital signs were monitored continuously. We evaluated blood gas analysis parameters before treatment and after 1 h of ventilation. ResultsDuring the study period, there were 78 full term newborns admitted in our NICU for neonatal distress who were treated with nCPAP ore nBIPAP ventilation. In nBiPAP patients, we noticed a statistically significant reduction in PaCO2 levels and FiO2 requirement with respect to nCPAP patients, after 1 h of ventilation with a simultaneous significant increase of pH and PaO2 levels. There was no difference in the length of NIV and hospital stay. Among nCPAP patients, two were then intubated and one developed a pneumothorax. ConclusionThe results of our study showed that an early BiPAP ventilation on RDS is the more efficient NIV because it improves CO2 removal and reduces FiO2 requirement in comparison to nCPAP. Future studies can clarify if early BiPAP ventilation on RDS is the more efficient of NIV.

Value of serum cholinesterase in the prognosis of septic shock

To investigate the relationship between serum cholinesterase (SChE) level and the prognosis of patients with septic shock (SS). A total of 594 patients with SS admitted to the First Affiliated Hospital of Zhengzhou University from June 2013 to June 2017 were enrolled. General data such as gender, age, acute physiology and chronic health evaluation II (APACHE II) score were recorded as well as routine blood test, procalcitonin (PCT), hepatic function, renal function, coagulation function and blood gas analysis parameters within 48 hours of SS diagnosis. The patients were followed by telephone from September to October in 2019, and the outcome was recorded. The primary outcome was all-cause death 28 days after discharge. The secondary outcomes were all-cause death in intensive care unit (ICU) and 2 years after discharge, and the length of ICU stay. The patients were divided into two groups according to prognosis of 28 days: the survival group and the death group. The clinical data of the two groups were compared. Multivariate Cox regression analysis was used to screen prognostic risk factors of 28 days in patients with SS. The receiver operating characteristic (ROC) curve was used to explore predictive value of liver function parameter SChE for 28-day prognosis of patients with SS. The patients were divided into two groups according to the levels of SChE: the low SChE group (SChE ≤ 4 000 U/L) and the normal SChE group (SChE > 4 000 U/L). Kaplan-Meier survival curves were used to compare the cumulative survival rates without endpoint event of patients with different SChE levels. A total of 385 patients with SS were enrolled according to the inclusion and exclusion criteria, and a total of 356 patients were followed up successfully, with a follow-up rate of 92.5% (356/385). There were 142 survival patients and 214 death patients at 28 days, with a 28-day mortality rate of 60.1% (214/356). There were 116 survival patients and 240 death patients at 2 years, with a 2-year mortality rate of 67.4% (240/356). Compared with the 28-day survival group, the patients in the death group were older and had higher APACHE II score, partial hepatic and renal function parameters, higher level of blood lactate (Lac) and lower levels of white blood cell count (WBC), platelet count (PLT) and SChE with statistically significant differences. Multivariate Cox regression analysis showed that the age [relative risk (RR) = 1.444, 95% confidence interval (95%CI) was 1.090-1.914, P = 0.010], APACHE II score (RR = 2.249, 95%CI was 1.688-2.997, P = 0.000), SChE (RR = 1.469, 95%CI was 1.057-2.043, P = 0.022), and Lac (RR = 2.190, 95%CI was 1.636-2.931, P = 0.000) were independent risk factors for 28-day mortality of patients with SS. The ROC curve analysis showed that SChE had a weak prognostic value for 28-day prognosis of patients with SS [the area under ROC curve (AUC) was 0.574]. However, the combined predictive value of SChE, APACHE II score and Lac was greater than APACHE II score or Lac alone for prediction (AUC: 0.807 vs. 0.785, 0.697), with a sensitivity of 79.9% and a specificity of 68.5%. Compared with the normal SChE group (n = 88), the 28-day mortality of patients in the low SChE group (n = 268) was significantly increased [63.1% (169/268) vs. 51.1% (45/88), P < 0.05], but ICU mortality [59.7% (160/268) vs. 48.9% (43/88)], 2-year mortality [69.8% (187/268) vs. 60.2% (53/88)] or the length of ICU stay [days: 4 (2, 7) vs. 5 (2, 9)] between the two groups showed no statistical significance (all P > 0.05). Kaplan-Meier survival curve analysis showed that the cumulative survival rate without endpoint event of patients in the low SChE group was significantly lower than that in the normal SChE group (Log-Rank test: χ2 = 5.852, P = 0.016). Increased risk of 28-day mortality in patients with SS whose SChE is below normal. The level of SChE is an independent risk factor for 28-day death in SS patients, and it is one of the indicators to evaluate the short-term prognosis of patients with SS.

Weaning from tracheostomy in subjects undergoing pulmonary rehabilitation

Background: Weaning from tracheostomy has implications in management, quality of life, and costs of ventilated patients. Furthermore, endotracheal cannula removing needs further studies. Aim of this study was the validation of a protocol for weaning from tracheostomy and evaluation of predictor factors of decannulation.&#x0D; Methods: Medical records of 48 patients were retrospectively evaluated. Patients were decannulated in agreement with a decannulation protocol based on the evaluation of clinical stability, expiratory muscle strength, presence of tracheal stenosis/granulomas, deglutition function, partial pressure of CO2, and PaO2/FiO2 ratio. These variables, together with underlying disease, blood gas analysis parameters, time elapsed with cannula, comordibity, Barthel index, and the condition of ventilation, were evaluated in a logistic model as predictors of decannulation.&#x0D; Results: 63 % of patients were successfully decannulated in agreement with our protocol and no one needed to be re-cannulated. Three variables were significantly associated with the decannulation: no pulmonary underlying diseases (OR = 7.12; 95 % CI 1.2–42.2), no mechanical ventilation (OR = 9.55; 95 % CI 2.1–44.2) and period of tracheostomy ≤10 weeks (OR = 6.5; 95 % CI 1.6–27.5).&#x0D; Conclusions: The positive course of decannulated patients supports the suitability of the weaning protocol we propose here. The strong predictive role of three clinical variables gives premise for new studies testing simpler decannulation protocols.

Arterial blood gas analysis utility in predicting lung injury in blunt chest trauma

Backgroundthoracic trauma is one of the leading causes of death in all age groups and accounts for 25–50 % of all traumatic injuries. With the term lung injury in blunt chest trauma, we identified a spectrum of conditions: lung contusion, pneumothorax and haemothorax. The aim of this study was to evaluate the utility of arterial blood gas analysis parameters in predicting lung injury in blunt chest trauma. Methodswe included 51 patients presenting to the Emergency Department of “C.T.O.” Hospital in Naples [Italy] for blunt chest trauma. The patients were assigned to the Lung Injury Group or to the Non-Lung Injury Group basing on CT scan findings. For each patient, we calculated the alveolar-arterial oxygen gradient [AaDO2], the AaDO2 augmentation, the arterial partial pressure of oxygen deficit [PaO2 Deficit] and the ratio between arterial partial pressure of oxygen and fraction of inspired oxygen [P/F]. Areas under the curve [AUC] and receiver operating characteristic [ROC] curve were used to compare the performance of each different test in relation to the detection of lung injury in blunt chest trauma. Resultspatients with lung injury had lower oxygen saturation, arterial partial pressure of oxygen, P/F and higher PaO2 Deficit, AaDO2, AaDO2 augmentation than patients without lung injury. PaO2 Deficit, AaDO2 and AaDO2 augmentation showed a good accuracy to predict lung injury in blunt chest trauma. Conclusionour study demonstrates that the combination of different arterial blood gas analysis variables may be a fast approach for identifying patients with lung injury in the setting of blunt chest trauma in the Emergency Department.

Effects of interposed abdominal pulling-pressing cardiopulmonary resuscitation on hemodynamics and oxygen metabolism in patients with cardiac arrest

To analyze the effect of interposed abdominal pulling-pressing cardiopulmonary resuscitation (IAPP-CPR) and standard cardiopulmonary resuscitation (S-CPR) on hemodynamics and oxygen metabolism in patients with cardiac arrest, and to evaluate the treatment effect of IAPP-CPR. The patients with cardiac arrest, cardiac arrest time less than 30 minutes, and with S-CPR indications admitted to intensive care unit (ICU) of the First People's Hospital of Lianyungang from January 2017 to January 2019 were enrolled. The patients were divided into IAPP-CPR group and S-CPR group according to whether the patients had IAPP-CPR indication or not. The patients in the S-CPR group were operated according to the 2015 American Heart Association (AHA) CPR guidelines; and the patients in the IAPP-CPR group received the IAPP-CPR on the basis of the S-CRP. During the relaxation period, the patients were subjected to abdominal lifting and compressing with amplitude of 4-5 cm, frequency of 100-120 times/min, and the time ratio of lifting to compressing was 1:1. Hemodynamic changes during resuscitation were recorded in the two groups. Hemodynamics, oxygen metabolism, arterial blood gas analysis and prognostic indicators were recorded at 30 minutes after successful resuscitation. During the study period, 77 patients were selected, 24 patients were excluded from giving up treatment and quitting, 53 patients were enrolled in the analysis finally, with 28 patients in the S-CPR group and 25 in the IAPP-CPR group. (1) The heart rate (HR), mean arterial pressure (MAP) and coronary perfusion pressure (CPP) showed an upward trend during resuscitation, and a more significant increase was shown in the IAPP-CPR group. (2) Hemodynamics after successful resuscitation: there were 16 patients with successful resuscitation in the IAPP-CPR group and 13 in the S-CPR group. The MAP, CPP, global ejection fraction (GEF) and stroke volume (SV) of patients with successful resuscitation at 30 minutes after resuscitation in the IAPP-CPR group were significantly higher than those in the S-CPR group [MAP mmHg (1 mmHg = 0.133 kPa): 52.88±3.11 vs. 39.39±4.62, CPP (mmHg): 36.56±6.89 vs. 29.61±6.92, GEF: 0.217±0.036 vs. 0.178±0.027, SV (mL): 38.43±5.25 vs. 32.92±8.28, all P < 0.05], but there was no significant difference in central venous pressure (CVP) or HR between the two groups. (3) Oxygen metabolism after successful resuscitation: the cardiac output (CO), arterial oxygen content (CaO2), oxygen transport (DO2) and oxygen consumption (VO2) of patients with successful resuscitation at 30 minutes after resuscitation in the IAPP-CPR group were significantly higher than those in the S-CPR group [CO (L/min): 2.23±0.38 vs. 1.99±0.29, CaO2 (mL/L): 158.0±11.8 vs. 141.4±8.2, DO2 (mL/L): 245.8±29.9 vs. 209.1±28.0, VO2 (mL/L): 138.2±24.9 vs. 112.8±18.1, all P < 0.05]. (4) Arterial blood gas after successful resuscitation: the values of the pH, arterial oxygen partial pressure (PaO2), arterial partial pressure of carbon dioxide (PaCO2), oxygenation index (PaO2/FiO2) and central venous oxygen saturation (ScvO2) of patients with successful resuscitation at 30 minutes after resuscitation in the IAPP-CPR were significantly higher than those in the S-CPR group [pH value: 7.13±0.22 vs. 7.00±0.23, PaO2 (mmHg): 73.68±13.80 vs. 65.32±15.32, PaCO2 (mmHg): 36.24±11.77 vs. 29.12±7.82, PaO2/FiO2 (mmHg): 73.68±13.80 vs. 65.32±15.32, ScvO2: 0.628±0.074 vs. 0.589±0.066, all P < 0.05], and the blood lactic acid (Lac) level was significantly lower than that in the S-CPR group (mmoL/L: 9.80±4.28 vs. 12.18±3.63, P < 0.05). (5) The patients in the IAPP-CPR group had a shorter time for cardiac arrest to restoration of spontaneous circulation (ROSC) than that in the S-CPR group (minutes: 10.63±2.94 vs. 14.54±3.84, P < 0.01), and the rate of ROSC, CPR successful rate and 28-day survival rate were significantly higher than those in the S-CPR group [64.0% (16/25) vs. 46.4% (13/28), 60.0% (15/25) vs. 28.6% (8/28), 52.0% (13/25) vs. 21.4% (6/28), all P < 0.05]. There was no significant difference in incidence of rib fracture between the IAPP-CPR and S-CPR groups [92.0% (23/25) vs. 89.3% (25/28), P > 0.05], and no abdominal bleeding was found in both group. IAPP-CPR can produce better hemodynamic effect during and after resuscitation than S-CPR, and oxygen metabolism and arterial blood gas analysis parameters at 30 minutes after resuscitation were better than S-CPR, with higher ROSC rate, CPR successful rate and 28-day survival rate, and no significant difference in complications between the two resuscitation methods.

The Dynamics of Gas Analysis Parameters in Young Males of the Magadan Region from Different Generations of Europeoid Migrants and Adaptants

Using indirect calorimetry, we examined 1632 young males aged 17 to 21 years, belonging to the Europeoid (Caucasian) race and residing permanently in the city of Magadan. Depending on the duration of adaptation to the conditions of the Northeast of Russia, all male subjects were divided into 3 groups of generation 1, 2 and 3 descendants and a group of newcomers (migrants or adaptants) residing in the Magadan Region for a short period of time (generation 0). It was established that in the lineage from generations 0 to 3 there occurred an optimization of the ventilatory characteristics of the external respiration apparatus aimed at cutting respiratory heat losses during adaptation to extreme conditions of the Northeast, i.e. a decrease in the tidal volume, tidal minute volume, and respiratory rate. Relevant rearrangements of the ventilatory pattern in subjects with a longer duration of residence under the same extreme conditions are paralleled by an improvement of oxygen transport and more efficient use of each respiratory cycle.

Lung separation in children: Options and impact on gas exchange and lung compliance.

One-lung ventilationis a challenging airway technique in the pediatric population. Multiple airway devices can be employed, but there is no consensus as to the most reliable and physiologically advantageous method. This report is a review of the methods of one-lung ventilationin children in our practice, as well as an analysis of the impact of airway device type, patient age, and duration of lung separation on respiratory mechanics and gas exchange. The records of all pediatric patients undergoing procedures requiring one-lung ventilation in a single center over an 18-month period were reviewed. Demographics, time required to achieve lung separation (anesthesia ready-time), and duration of one-lung ventilation were collected. Data from arterial blood gas analysis and ventilator parameters were collected at three time points: 15minutes prior to one-lung ventilation (pre-OLV), 15minutes after initiation of one-lung ventilation (during OLV), and 15minutes after one-lung ventilation was ended (post-OLV). Standard equations for calculating compliance, the ratio of arterial partial pressure of oxygen to the fraction of inspired oxygen, and the alveolar-arterial oxygen gradient were used. Forty-six patients were identified with a mean age of 9.3 (inner quartile range 3-15) years. All patients had significant changes in pulmonary function when comparing pre-OLV with during OLV and when comparing during OLV with post-OLV. There were no significant changes from pre- to post-OLV. On further analysis, there were more pronounced changes in compliance and gas exchange in older patients (P=0.003; 95% CI: -0.62 to -0.14). There was also a significant decrease in post-OLV compliance with a longer duration of OLV (P=0.018; 95% CI: -0.02 to <-0.01). Airway device type did not have significant impact on the parameters examined. Our report demonstrates significant changes in lung function during one-lung ventilation. One particular device does not seem to be superior. Though pre-OLV measures of pulmonary function correlate closely with post-OLV, older age and a prolonged duration of one-lung ventilation did impact compliance.

The comparison of blood gas analysis (BGA) parameters in samples transported by the pneumatic tube system and manual transport at Dr. Soetomo Hospital, Surabaya, Indonesia

Background: Pneumatic Tube System (PTS) can reduce the time needed to transport laboratory samples, thus resulting in faster turn-around time. Blood gas analysis (BGA) is a critical laboratory examination, and it would benefit from sending the sample using PTS. Some studies showed the effect of PTS on BGA’s parameters, so the laboratory should validate the usage of PTS before delivering the samples. This study aims to determine the comparison of BGA parameters in Sample Transported by Pneumatic Tube System and Manual Transport at Dr. Soetomo Hospital, Surabaya, Indonesia.Method: A cross sectional analytic study was conducted among 31 blood patients and divided into two syringes. One syringe was delivered by PTS as well as the other was transported by courier. The delivery distance was 250 meters for both transportations. Both samples then were examined by qualified laboratory analyst. The pH, pCO2, and pO2 were compared. Data were analyzed using SPSS version 17 for windows.Result: The result of pH, pO2 and pCO2 in PTS samples was not significantly different compared to manual transportation (p=0,799; p=0,955 and p=0,856 respectively). Bland-Altman plot was found a good agreement between both types of transportation method.Conclusion: The result of this study showed no significant difference in BGA’s parameters sent by PTS or manual transportation. PTS can be used to replace manual transportation in delivering blood gas samples to the central laboratory.

Assessment of the hemodynamics of pulmonary artery and right ventricular function in chronic obstructive pulmonary disease with pulmonary hypertension using cardiac magnetic resonance imaging

To investigate the role of cardiac magnetic resonance imaging (CMRI) in evaluating pulmonary hemodynamics and right ventricular function in patients with chronic obstructive pulmonary disease (COPD) and pulmonary hypertension (PAH); and the relationship between CMRI parameters and pulmonary function parameters, blood gas analysis parameters and 6-minute walk test (6MWT) parameters in patients with COPD complicated with PAH. Thirty-seven patients were diagnosed with COPD in the department of respiratory and critical care discipline of Ningxia Medical University General Hospital from October 2013 to October 2016, who underwent transthoracic echocardiography (TTE) to measure pulmonary arterial systolic pressure (PASP), and were divided into COPD group and COPD+PAH group according to whether there was PAH [PASP > 40 mmHg (1 mmHg = 0.133 kPa) was defined as PAH]. All patients completed pulmonary function tests [1 second forced expiratory volume to forced vital capacity ratio (FEV1/FVC), FEV1 predicted value (FEV1pred)], blood gas analysis [arterial blood oxygen partial pressure (PaO2), arterial blood carbon dioxide partial pressure (PaCO2)], CMRI examination [relative dilatation of the main pulmonary artery (mPAD), mean pulmonary artery pressure (mPAP), left ventricular ejection fraction (LVEF), right ventricular ejection fraction (RVEF), right ventricular end-diastolic myocardial mass (RVMED), right ventricular end-systolic myocardial mass (RVMES)], and 6MWD [6-minute walk distance (6MWD)] within 1 week. The obtained clinical parameters had been compared between the groups, and correlation was analyzed. Among the 37 patients with COPD, 16 patients were complicated with PAH. There were no significant differences in FEV1/FVC, FEV1pred, PaO2, PaCO2 and other baseline indicators between the two groups. In the COPD group, TTE obtained PASP of 2 patients were normal (PSAP < 40 mmHg), while CMRI measured mPAP were higher than the normal limit (> 25 mmHg). Compared with the COPD group, mPAD, RVEF and 6MWD were significantly decreased in the COPD+PAH group [mPAD: (25.64±5.01)% vs. (44.00±22.52)%, RVEF: 0.525±0.054 vs. 0.592±0.071, 6MWD (m): 319.3±116.5 vs. 408.2±38.0, all P < 0.01], mPAP, RVMED and RVMES were significantly increased [mPAP (mmHg): 28.89±3.16 vs. 20.18±2.43, RVMED (g): 57.19±15.46 vs. 40.71±15.44, RVMES (g): 45.99±11.16 vs. 33.71±13.39, all P < 0.01], and there was no significant differences in LVEF (0.663±0.082 vs. 0.699±0.075, P > 0.05). Correlation analysis showed that mPAD was positively correlated with FEV1/FVC and FEV1pred (r1 = 0.538, P1 = 0.021; r2 = 0.448, P2 = 0.049); RVMED was negatively correlated with PaO2 (r = -0.581, P = 0.015), and positively correlated with PaCO2 (r = 0.592, P = 0.014); 6MWD was positively correlated with RVEF (r = 0.485, P = 0.041), and had no correlation with LVEF (r = 0.271, P = 0.104). Compared with COPD patients, changes in pulmonary hemodynamics and right ventricular function in COPD patients with PAH are related to the severity of airflow limitation. CMRI can early monitor pulmonary hemodynamics and right heart function changes in patients with COPD. Once PAH appears, pulmonary hemodynamics, right heart function and exercise tolerance have changed.

Usefulness of ventilatory gas analysis for the non-invasive evaluation of the severity of chronic thromboembolic pulmonary hypertension

BackgroundChronic thromboembolic pulmonary hypertension (CTEPH) is characterized by organic thrombotic obstructions in the pulmonary arteries with reduced pulmonary vascular reserve. This study aimed to examine whether postural changes in ventilatory gas analysis parameters are useful for assessing pulmonary hemodynamics in patients with CTEPH. MethodsA total of 44 patients with newly diagnosed CTEPH (CTEPH group), 33 patients with improved CTEPH (mean pulmonary arterial pressure [mPAP] <25 mm Hg), and 25 controls were enrolled. Patients with improved CTEPH referred to patients without residual PH who were previously diagnosed with CTEPH and already received optimal therapies. Various pulmonary function parameters were examined in supine and sitting positions, and postural changes were calculated (Δ[supine − sitting]). In 32 patients with CTEPH, we examined hemodynamic and ventilatory gas analysis parameters before the first balloon pulmonary angioplasty (BPA) and during follow-up. ResultsPatients with CTEPH had significantly lower supine end-tidal carbon dioxide pressure (PETCO2) and ΔPETCO2 than controls (both P < 0.001), and these parameters were significantly correlated with mPAP (R2 = 0.507, P < 0.0001 and R2 = 0.470, P < 0.001, respectively). Supine PETCO2 and ΔPETCO2 were significantly lower in patients with improved CTEPH than in controls (both P < 0.001). Hemodynamic and echocardiographic parameters were comparable in both groups. Furthermore, significant correlation between the change in mPAP and change in supine PETCO2 by BPA was noted (R2 = 0.478, P < 0.001). ConclusionThese results indicate that postural changes in ventilatory gas analysis parameters are useful and non-invasive method for the evaluation of mPAP, which is one of the hemodynamic parameters of CTEPH severity.

Influence of different PEEP levels on electrical impedance tomography findings in patients under general anesthesia ventilated in the lateral decubitus position.

To determine the effect of various PEEP levels on electrical impedance tomography (EIT) measured differences in regional ventilation, hemodynamics, lung mechanics and parameters of alveolar gas exchange. Thirty three patients scheduled for elective urologic surgery in general anesthesia in lateral decubitus position were randomized into three groups—PEEP 0, 5 and 10 mbar. EIT recording, arterial blood gas analysis and hemodynamic parameters were captured at three timepoints—before induction (T0), 5 min after lateral positioning (T1) and 90 min after positioning (T2). Dynamic compliance (Cdyn) was measured at T1 and T2. Offline EIT data analysis was performed to calculate EIT derived parameters of ventilation distribution. Patients ventilated with PEEP of 10 mbar had a significantly lower A-a (alveolo arterial) gradient over measurements and symmetrical distribution of ventilation measured by EIT. There was no significant difference in Cdyn, center of ventilation indices and inhomogeneity index between groups. There was no difference of mean arterial pressure, cardiac index and heart rate between groups. Patients with 5 mbar of PEEP had higher stroke volume index compared to 0 and 10 mbar at baseline and over measurements. Nondependent/dependent TV ratio as well as global inhomogeneity index were correlated with A-a gradient. Dynamic compliance showed no correlation to A-a gradient. In our study, a PEEP level of 10 mbar improved alveolar gas exchange without compromising hemodynamic stability in patients mechanically ventilated in the lateral decubitus position. EIT measured parameters may be used to determine optimal ventilation parameters in these patients with inhomogeneous lung mechanics. Further studies are needed in patients with various lung pathologies.

The Protective Effect of Prone Positioning on Human Rejected Donor Lungs during Cellular Ex Vivo Lung Perfusion

Purpose We previously reported that prone positioning (PP) of porcine lungs during cellular ex vivo lung perfusion (EVLP) diminished inflammatory injury and improved oxygenation and other pulmonary parameters during cellular EVLP. We hypothesized that prone positioning of human lungs during cellular EVLP may diminish injury and improve function, as well. The aim of this study is to validate the previous results with porcine lungs and evaluate the potential benefits of PP EVLP with human rejected donor lungs. Methods Eleven human rejected donor lungs were flushed and stored for 15-16 hours with Perfadex. Lungs were then subjected to 2 hours of cellular EVLP with either maintenance of prone positioning (prone group, n = 6) or supine positioning (control group, n = 5). Lung function was evaluated using blood gas analysis, airway and vascular parameters, visual findings, wet/dry (W/D) ratio and lung weight at 2 hours of EVLP. Results Lung weight (LW) ratio (LW at 2 hours of EVLP/ LW prior to EVLP) was lower in Prone group than in Control group [median (interquartile range)] [1.09 (0.82-1.32) vs. 1.22 (1.01-1.50), p = 0.5] (not statistical significant). The PaO2/FiO2 (P/F) ratio of left atrial blood was significantly higher in Prone group than in Control [335.5 (297.2-392.5) vs. 198.0 (190.5-271.0) mmHg, p Conclusion These results demonstrate that PP during 2 hours of cellular EVLP result in less lung weight gain, and better P/F ratio, especially in the lower lobes. These results were consistent with our previous animal study, and suggest that prone positioning EVLP of rejected human donor lungs also may diminish IRI during EVLP.

Neurologic recovery after deep hypothermic circulatory arrest in rats: A description of a long-term survival model without blood priming.

Brain injury associated with deep hypothermic circulatory arrest (DHCA) has been recognized in patients with congenital heart diseases and those undergoing aortic arch surgeries. However, the preclinical investigation of long-term cerebral injury and recovery mechanisms related to DHCA has been restricted to a satisfactory recovery animal model with a determined recovery time. This study aimed to evaluate the feasibility of a long-term surviving DHCA model without blood priming in rats, in order to investigate the pathophysiology of long-term complications in further studies. Twelve Sprague-Dawley rats were divided into 2 groups: sham group (n=3) and DHCA group (n=9). The DHCA group was further assigned to the surviving time of postoperative day 2, 14, and 30 (n=3, respectively). The entire cardiopulmonary bypass (CPB) circuit consisted of a modified reservoir, a custom-designed small-volume membrane oxygenator, a roller pump and a heater/cooler. A 24-G catheter was cannulated in the branch of the left femoral artery for arterial blood pressure monitoring. Cardiopulmonary bypass was established via the right external jugular vein-right atrium and tail artery. Rats were cooled to a rectal temperature of 18°C, followed by 30minutes of DHCA with global ischemia. After re-warming for approximately 40minutes, the animals were weaned from the CPB at 35.5°C. Blood gas and hemodynamic parameters were recorded preoperatively and intraoperatively, and at 2, 14, and 30 days postoperatively. Thereafter, the brains were perfusion fixed and histologically analyzed. All DHCA processes were successfully achieved, and none of the rats died. Blood gas analysis and hemodynamic parameters at each time point were normal, and vital signs of all rats were stable. Histopathologic deficits in the hippocampus (pathological score, surviving hippocampal neurons, and Ki67-positive neurons) manifested after 30 minutes of DHCA, which persisted for at least 14 days and recovered after 30 days. A novel and simple long-term recovery model of DHCA in rats was established in the present study, and histopathologic deficits were observed after clinically relevant 30-minute DHCA durations, in order to determine the 30-day recovery time frame.