Background: It is necessary to determine the value of PAO2 and PACO2 in COPD patients for diagnosis the severity of chronic bronchitis diseases and their separation from other diseases.For the diagnosis of COPD diseases and their separation from other diseases and for having a criterion for treatment with oxygen, we need to know the amount of PAO2 and PACO2 in patients; ABG is an invasive and difficult procedure.Materials and Methods: This cross sectional study was carried out on 118 consecutive patients with chronic bronchitis referring to Afshar hospital in Yazd in order to determine the correlation between spirometry FEV1 and ABG parameters.Results: The study population included 82 (69.5%) males and 36(30.5%) females with the mean age of 71.6±9 years. The mean FEV1 (% pred.) was 42.88±15.12, mean PAO2 was 55.31±13.51 mmHg and mean PACO2 was 51.64±10.56 mmHg. FEV1 was positively correlated with PAO2 (r=0.418, p<0.0001) and inversely correlated with PACO2 (r= -0.533, p<0.0001).Conclusion: One could establish a reliable equation indicating the correlation between FEV1 and PAO2 as well as PACO2 in patient with chronic bronchitis.

Background: In patients under mechanical ventilation, the patient's position is one of the factors affecting the efficiency of respiratory gas exchange. The aim of this study was to compare the level of arterial blood gas pressure and the percentage of arterial oxygen saturation in the supine position with the lateral position in patients with ventilator-associated pneumonia. Methods: In a clinical trial study with a sample size of 50 patients with ischemic stroke under mechanical ventilation admitted to the intensive care unit of Kashani hospital affiliated to Shahrekord University of Medical Sciences, Shahrekord, Iran, in 2019 were selected using convenience sampling method. Oxygen saturation percentage was measured by a pulse oximeter in patients lying on their backs and then, on their sides for two hours,arterial blood pressure and carbon dioxide levels were measured with arterial blood sample by laboratory device, and recorded in the relevant checklist as well. Findings: In both supine and lateral positions, the mean arterial oxygen pressure and the percentage of hemoglobin oxygen saturation were not significantly different (P > 0. 050),while the arterial carbon dioxide pressure in the lateral position was significantly lower than the supine position (P = 0. 008). Conclusion: The lateral position has no significant effect on the improvement of arterial blood gases and oxygen saturation in patients with pneumonia due to mechanical ventilation,but has significantly reduce the pressure of carbon dioxide.

It is very important to know about ABG in order to evaluate the oxygenation potency of lungs especially in critically ill patients. Many factors such as geographical position do affect ABG. This cross-sectional study was done on 83 healthy young persons having no systemic or other kinds of diseases affecting arterial blood gases. Information on PH, PAO2, ao2, Spo2 and Spo2 were gathered from each person. The obtained results were statistically analyzed using t-test. The mean PAO2 and PACO2 were 111.77 and 41.49 mmHg respectively (see also tables). In the present study, special geographical position of Sari in the vicinity of the Caspian Sea has affected the abovementioned parameters, so that PAO2 is much higher. Therefore a higher level of arterial oxygen is to be considered hypoxia in order to prevent the hypoxia risk.

History and Objectives: Nocturnal hypoxemia in patients with chronic obstructive pulmonary disease (COPD) is a frequent side effect. Because there is frequent occurrence of pulmonery hypertension and cardiac al7hythmia in these patients, it is important to diagnose and treat nocturnal hypoxemia. In this research we investigated the changes of hypertension and hypoxemia during day and night in patients with COPD who were referred to the internal medicine ward of Shahid Beheshti Hospital in 1999. Materials and Methods: A descriptive study was conducted on 68 patients with COPD. Arterial blood gas measurement was performed from radial artery in sapine position in duplicates in the day and at night. Mean PAO2 and PACO2 during day and night and changes of mean PAO2 in different levels of hypercapnia were determined. Results: Night time decrease in PAO2 and SaO2 and increase in PaC O2 was significant compare to the day time values (day: PAO2 = 62.2±13.9 mmHg, night: 57.6±12.2.p<0.00l, day: SaO2 =88±7.5%, night: Sa O2 = 66±9%, p<0.001, day: PACO2 = 46±7.5 mmHg, night: PACO2 = 47.6±8 mmHg, p <0.001). The decrease in PAO2 during night in patients with PAO2<60 mmHg wasmore than inpatients with PAO2>60 mmHg (7.4±12. 7mmHg, 1.4±7.6mmHg, respectively, p=0.019). In patients with PACO2 <45mmHg and PACO2>45 mmHg, Pa O2 in the day and night were 66.8±12.7 mmHg, 62.1±10.4 mmHg, 57.7±13.8 mmHg, 53.1±12.4 mmHg respectively. The amount of changes in both groups was 6.97% and 7.85% respectively. Conclusions: Hypoxemia and hypercapnia are increased during night in patients with COPD. The amount decrease in nocturnal hypoxemia depends on its amount in the day. The amount of decrease in hypoxemia depends on the degree of hypercapnia. In patients with COPD, who has hypercapnia and hypoxemia, O2 delivery in the night and the improvement of hypoxemia is very important      

Background: Arterial Blood Gas (ABG) analysis is a commonly ordered test to investigate respiratory, circulatory, and metabolic status in traumatic patients with inappropriate perfusion and ventilation situations. Difficult sampling, hemorrhage risk of arterial puncture, and other vascular complications lead us to use saliva sampling as a safer non-invasive approach to evaluate PAO2, PACO2, pH, and HCO3 values. This study was aimed to evaluate the correlation of PAO2, PACO2, pH, and HCO3 values between ABG and saliva gas in traumatic patients under mechanical ventilation. Methods: This was a retrospective cross-sectional study of 18-85-year-old traumatic patients under mechanical ventilation conducted in an academic medical hospital. They were investigated based on age, sex, and ABG values as well their saliva gases values. The Paired t-test, Pearson χ, 2, and Pearson correlation were used to evaluate the correlation between the gases values in ABG and saliva. Data were analyzed using Mann–, Whitney U test and Kolmogorov–, Smirnov test. Results: There were 120 patients including 53 men and 67 women enrolled. None of the factors of arterial and salivary gases were significantly different between men and women. And the amount of these factors is homogeneous in both groups (P <0. 05). The mean factors of arterial PACO2 and HCO3 and saliva PACO2 and HCO3 were significantly different between smokers and non-smokers. Conclusion: The values of salivary gases correlated with these of ABG. This can expand the use of salivary gases analysis as an alternative to ABG analysis in clinical settings to reduce the logistic burden of arterial sampling as well as to better perform ventilator device settings. These results were aligned with previous studies.

Aim. The aim of this study was to examine the effect of incentive spirometry and deep breathing exercises on arterial blood gas parameters after coronary artery bypass graft (CABG) surgery.Background. After CABG, pulmonary complications and oxygenation disorders are common and play an important role in post-operative mortality and morbidity. The different methods are being used for improvement of pulmonary function and oxygenation after CABG.Method. In this clinical trial study, 75 patients who were candidate for CABG surgery were recruited and randomly allocated to two intervention groups (incentive spirometry group and deep breathing exercise group) and control group. The groups were compared in terms of arterial blood gas parameters (PAO2, PACO2 and SaO2) before surgery, and on the first day, the second day, and the third day after surgery.Findings. The study findings showed that in the third postoperative day, there was a statistically significant difference between intervention groups and control group in terms of the mean of arterial blood gas parameters (PAO2, PACO2 and SaO2).Conclusion. Incentive spirometry and deep breathing exercise are both significantly effective on improvement of arterial blood gas parameters (PAO2, PACO2 and SaO2).

Objective: We try to answer the question of '' how much will (co2) of blood change if we keep the amount of fresh gases constant" the subject of the present study on patients in Tajrish hospital in winter 1998.Methods: This research was done on 80 adults in the age group of 15-65. Who was under goung a surgical operation of lung. This was clinical trial using double blind sequential method subjects in control group were giner inspirations (12/min) and 12 times in the first 30 minutes for those in test group and in both groups the PACO2 of blood was measured by the AVL system during the first 30 and 60 minutes. The amount of drug used before anesthesia and also the amount of anesthetic gases has been equal in both groups.Findings: The research outcome has shown that the amount of PACO2 was not changed at all in control group where as it has increased among the experimental subjects from 28.74±3.38 in the first half hour to 34.32 ±3.65 in the first hour. While paired t test showed that this 20% increase can be noticeable, statistics (p<0.001) and the changes of PACO2 in both groups also revealed to be clear and meaningful (p<0.001).Conclusion: The results have shown that increased respiratory rate increases the level of PACO2, although such increments would be considered normal.  

Background: End-tidal carbon dioxide (EtCO2) can approximate the arterial pressure of carbon dioxide (PACO2) in children without underlying congenital heart defects. However, EtCO2may underestimate PACO2in these children, especially during repair procedures. The PACO2to EtCO2difference (Δ PACO2-EtCO2) may be significant in children with congenital heart disease (CHD) and can be notably influenced by surgical procedures. Postoperatively, the Δ PACO2-EtCO2might not remain consistent,thus, arterial blood gas (ABG) analysis may need to be repeated regardless of capnography findings. This hypothesis was tested in our study on children with cyanotic and acyanotic heart defects undergoing corrective surgeries. Methods: In this cross-sectional study, hospital records of all children under 12 years of age with ASA II-III and cyanotic or acyanotic heart defects who were candidates for elective angiography were reviewed. EtCO2was measured by lateral aspiration capnography. Simultaneous measurements of EtCO2and PACO2were collected before and after the intervention. Results: Significant changes were observed in serum HCO3concentration and the PAO2/FiO2ratio, both of which significantly decreased after the repair surgery. However, the change in Δ PACO2-EtCO2remained insignificant postoperatively. In the cyanotic group, in addition to a significant reduction in serum HCO3value and an increase in the PAO2/FiO2ratio after the intervention, we found a significant decrease in Δ PACO2-EtCO2. Conclusion: Arterial blood gas analysis during repair surgery should be repeated in the cyanotic congenital heart defects group due to the intraoperative variability of Δ PACO2-EtCO2, but not in the acyanotic heart defects group due to the stability of this difference. Therefore, EtCO2assessed by capnography can estimate PACO2in children with acyanotic heart defects, but not in those with cyanotic heart defects