Pregnant sheep develop hypoxaemia during short-term anaesthesia for caesarean delivery

2018 ◽  
Vol 52 (5) ◽  
pp. 497-503
Author(s):  
Gabrielle C Musk ◽  
Matthew W Kemp

Short-term anaesthesia of the pregnant ewe may be required for caesarean delivery of a preterm foetus within a research protocol. The aim of this study was to evaluate and compare the acid-base and haematological status of the ewe and foetus at the time of surgical delivery by collecting maternal and foetal arterial blood samples. Fifteen date-mated singleton-pregnant merino cross ewes at 122.0 (±0.5) days of gestation were anaesthetised with a combination of midazolam (0.5 mg/kg) and ketamine (10 mg/kg) by intravenous injection. A subarachnoid injection of lidocaine (60 mg) was given to desensitise the caudal abdomen. Supplemental oxygen was not provided, and an endotracheal tube was not placed in the ewe’s trachea. The development of maternal respiratory acidosis (hypercapnia) and hypoxaemia was anticipated. Samples of arterial blood for blood gas analyses were collected simultaneously from the radial artery of the ewe and the umbilical artery of the foetus immediately after delivery. The results from the maternal blood samples were within the normal range for pH, partial pressure of carbon dioxide in arterial blood (PaCO2), base excess, glucose, lactate, haematocrit and haemoglobin concentration. The maternal partial pressure of oxygen in arterial blood (PaO2) revealed hypoxaemia: 45.2 (41.1–53.4) mmHg. Foetal arterial blood gas analysis revealed hypoxaemia (15.0 ± 3.1 mmHg) and hypoglycaemia (0.1 (0.1–1.1) mmol/L). The benefit of providing supplemental oxygen and/or placing an endotracheal tube must be carefully weighed against the benefit of saving time when prompt delivery of the foetus is planned. In this study the pregnant ewe developed severe hypoxaemia, and this abnormality may have contributed to a low foetal PaO2.

2019 ◽  
pp. 203-206
Author(s):  
Mevlut Demir ◽  
◽  
Muslum Sahin ◽  
Ahmet Korkmaz ◽  
◽  
...  

Carbon monoxide intoxication occurs usually via inhalation of carbon monoxide that is emitted as a result of a fire, furnace, space heater, generator, motor vehicle. A 37-year-old male patient was admitted to the emergency department at about 5:00 a.m., with complaints of nausea, vomiting and headache. He was accompanied by his wife and children. His venous blood gas measures were: pH was 7.29, partial pressure of carbon dioxide (pCO2) was 42 mmHg, partial pressure of oxygen (pO2) was 28 mmHg, carboxyhemoglobin (COHb) was 12.7% (reference interval: 0.5%-2.5%) and oxygen saturation was 52.4%. Electrocardiogram (ECG) examination showed that the patient was not in sinus rhythm but had atrial fibrillation. After three hours the laboratory examination was repeated: Troponin was 1.2 pg/ml and in the arterial blood gas COHb was 3%. The examination of the findings on the monitor showed that the sinus rhythm was re-established. The repeated ECG examination confirmed the conversion to the sinus rhythm. He was monitored with the normobaric oxygen administration.


2021 ◽  
Vol 11 (3) ◽  
pp. 517-521
Author(s):  
Alejandro Montero-Salinas ◽  
Marta Pérez-Ramos ◽  
Fernando Toba-Alonso ◽  
Leticia Quintana-DelRío ◽  
Jorge Suanzes-Hernández ◽  
...  

Aim. To evaluate the influence of time on arterial blood gas values after artery puncture is performed. Method. Prospective longitudinal observational study carried out with gasometric samples from 86 patients, taken at different time intervals (0 (T0), 15 (T15), 30 (T30) and 60 (T60) min), from 21 October 2019 to 21 October 2020. The study variables were: partial pressure of carbon dioxide, bicarbonate, hematocrit, hemoglobin, potassium, lactic acid, pH, partial pressure of oxygen, saturation of oxygen, sodium and glucose. Results. The initial sample consisted of a total of 90 patients. Out of all the participants, four were discarded as they did not understand the purpose of the study; therefore, the total number of participants was 86, 51% of whom were men aged 72.59 on average (SD: 16.23). In the intra-group analysis, differences in PCO2, HCO3, hematocrit, Hb, K+ and and lactic acid were observed between the initial time of the test and the 15, 30 and 60 min intervals. In addition, changes in pH, pO2, SO2, Na and glucose were noted 30 min after the initial sample had been taken. Conclusions. The variation in the values, despite being significant, has no clinical relevance. Consequently, the recommendation continues to be the analysis of the GSA at the earliest point to ensure the highest reliability of the data and to provide the patient with the most appropriate treatment based on those results.


Author(s):  
Kirsty L. Ress ◽  
Gus Koerbin ◽  
Ling Li ◽  
Douglas Chesher ◽  
Phillip Bwititi ◽  
...  

AbstractObjectivesVenous blood gas (VBG) analysis is becoming a popular alternative to arterial blood gas (ABG) analysis due to reduced risk of complications at phlebotomy and ease of draw. In lack of published data, this study aimed to establish reference intervals (RI) for correct interpretation of VBG results.MethodsOne hundred and 51 adult volunteers (101 females, 50 males 18–70 y), were enrolled after completion of a health questionnaire. Venous blood was drawn into safePICO syringes and analysed on ABL827 blood gas analyser (Radiometer Pacific Pty. Ltd.). A non-parametric approach was used to directly establish the VBG RI which was compared to a calculated VBG RI based on a meta-analysis of differences between ABG and VBGResultsAfter exclusions, 134 results were used to derive VBG RI: pH 7.30–7.43, partial pressure of carbon dioxide (pCO2) 38–58 mmHg, partial pressure of oxygen (pO2) 19–65 mmHg, bicarbonate (HCO3−) 22–30 mmol/L, sodium 135–143 mmol/L, potassium 3.6–4.5 mmol/L, chloride 101–110 mmol/L, ionised calcium 1.14–1.29 mmol/L, lactate 0.4–2.2 mmol/L, base excess (BE) −1.9–4.5 mmol/L, saturated oxygen (sO2) 23–93%, carboxyhaemoglobin 0.4–1.4% and methaemoglobin 0.3–0.9%. The meta-analysis revealed differences between ABG and VBG for pH, HCO3−, pCO2 and pO2 of 0.032, −1.0 mmol/L, −4.2 and 39.9 mmHg, respectively. Using this data along with established ABG RI, calculated VBG RI of pH 7.32–7.42, HCO3− 23 – 27 mmol/L, pCO2 36–49 mmHg (Female), pCO2 39–52 mmHg (Male) and pO2 43–68 mmHg were formulated and compared to the VBG RI of this study.ConclusionsAn adult reference interval has been established to assist interpretation of VBG results.


1978 ◽  
Vol 44 (4) ◽  
pp. 534-537 ◽  
Author(s):  
M. Maskrey ◽  
P. P. Hoppe ◽  
O. S. Bamford

Five adult male dik-dik (Madoqua kirkii) were exposed in a climatic chamber to an air temperature of 45 degrees C. Measurements were made of rectal temperature (Tre) and respiratory frequency (f) and arterial blood samples taken before and during heat exposure were analyzed for pH, PCO2 and PO2. During exposure, Tre and f increased in all animals. In the first 80 min dik-dik displayed thermal tachypnea and minor changes in blood gases. Continued exposure lead to hyperpnea accompanied by a fall in PaCO2 and a rise in pH. PaCO2 at first fell and then increased toward or above control levels. The dik-dik did not display second phase breathing. This observation confirms that second phase breathing is not essential to the development of respiratory alkalosis. The main conclusion of the study is that the dik-dik, unlike another heat-adapted antelope, the wildebeest (Taylor, Robertshaw, and Hoffmann. Am. J. Physiol. 217:907–910, 1969), is unable to resist alkalosis during heat stress.


Author(s):  
Nazlıhan Boyacı ◽  
Sariyya Mammadova ◽  
Nurgül Naurizbay ◽  
Merve Güleryüz ◽  
Kamil İnci ◽  
...  

Background: Transcutaneous partial pressure of carbon dioxide (PtCO2) monitorization provides a continuous and non-invasive measurement of partial pressure of carbon dioxide (pCO2). In addition, peripheral oxygen saturation (SpO2) can also be measured and followed by this method. However, data regarding the correlation between PtCO2 and arterial pCO2 (PaCO2) measurements acquired from peripheric arterial blood gas is controversial. Objective: We aimed to determine the reliability of PtCO2 with PaCO2 based on its advantages, like non-invasiveness and continuous applicability. Methods: Thirty-five adult patients with hypercapnic respiratory failure admitted to our tertiary medical intensive care unit (ICU) were included. Then we compared PtCO2 and PaCO2 and both SpO2 measurements simultaneously. Thirty measurements from the deltoid zone and 26 measurements from the cheek zone were applied. Results: PtCO2 could not be measured from the deltoid region in 5 (14%) patients. SpO2 and pulse rate could not be detected at 8 (26.7%) of the deltoid zone measurements. Correlation coefficients between PtCO2 and PaCO2 from deltoid and the cheek region were r: 0,915 and r: 0,946 (p = 0,0001). In comparison with the Bland-Altman test, difference in deltoid measurements was -1,38 ± 1,18 mmHg (p = 0.252) and in cheek measurements it was -5,12 ± 0,92 mmHg (p = 0,0001). There was no statistically significant difference between SpO2 measurements in each region. Conclusion: Our results suggest that PtCO2 and SpO2 measurements from the deltoid region are reliable compared to the arterial blood gas analysis in hypercapnic ICU patients. More randomized controlled studies investigating the effects of different measurement areas, hemodynamic parameters, and hemoglobin levels are needed.


1974 ◽  
Vol 60 (3) ◽  
pp. 901-908
Author(s):  
M. G. EMíLIO

1. The respiratory exchanges through the lungs and skin of frogs and the time courses of blood gas concentrations were studied during emergence and diving periods. 2. Most of the total oxygen uptake is carried out through the lungs. The partial pressure of oxygen in arterial blood falls to very low levels a few minutes after diving, showing that the cutaneous respiratory surface cannot compensate for the lack of lung respiration. 3. Most of the metabolic carbon dioxide is disposed of through the skin. Although the skin output is maintained through diving periods, there is an important rise in the partial pressure of carbon dioxide in blood following submergence. However, the total concentration of CO2 in the blood decreases, as does the blood pH value. 4. This phenomenon is probably the result of a metabolic acidosis due to the switching on of anaerobic processes during diving periods.


1993 ◽  
Vol 75 (1) ◽  
pp. 285-293 ◽  
Author(s):  
J. Qvist ◽  
W. E. Hurford ◽  
Y. S. Park ◽  
P. Radermacher ◽  
K. J. Falke ◽  
...  

Korean female unassisted divers (cachido ama) breath-hold dive > 100 times to depths of 3–7 m during a work day. We sought to determine the extent of arterial hypoxemia during normal working dives and reasonable time limits for breath-hold diving by measuring radial artery blood gas tensions and pH in five cachido ama who dove to a fixed depth of 4–5 m and then continued to breath hold for various times after their return to the surface. Eighty-two blood samples were withdrawn from indwelling radial artery catheters during 37 ocean dives. We measured compression hyperoxia [arterial PO2 = 141 +/- 24 (SD) Torr] and hypercapnia (arterial PCO2 = 46.6 +/- 2.4 Torr) at depth. Mean arterial PO2 near the end of breath-hold dives lasting 32–95 s (62 +/- 14 s) was decreased (62.6 +/- 13.5 Torr). Mean arterial PCO2 reached 49.9 +/- 5.4 Torr. Complete return of these values to their baseline did not occur until 15–20 s after breathing was resumed. In dives of usual working duration (< 30 s), blood gas tensions remained within normal ranges. Detailed analysis of hemoglobin components and intrinsic oxygenation properties revealed no evidence for adaptive changes that could increase the tolerance of the ama to hypoxic or hypothermic conditions associated with repetitive diving.


Author(s):  
Mark Feldman, MD ◽  
Denise Rebel, BS, RRT

The arterial partial pressure of oxygen in the arterial blood reveals limited information about pulmonary oxygen transfer. In 989 hospitalized patients undergoing arterial blood gas testing, we compared conventional indices of oxygen transfer: (1) P(A-a) O2 (A-a); (2) PaO2/PAO2 (a/A); and (3) the P/F ratio Nine hundred twenty-five of the patients were receiving supplemental oxygen therapy (FIO2 .24-1.00) and 65 were breathing room air. In patients receiving supplemental O2, the a/A ratio closely correlated with the P/F ratio (r = .98 to .99); the A-a O2 difference did not correlate as closely with the a/A ratio (r = -.77 to -.85) or with the P/F ratio (r = -.72 to -.80). In those breathing room air (FIO2 .21), the a/A ratio was closely and inversely correlated with the A-a difference (r= -.97 to -.98); correlations between the a/A and P/F ratios (r=.88 to .89) and between the P/F ratio and A-a O2 difference (r = -.78 to -.79) were less robust. We conclude that the a/A ratio is the preferred oxygen transfer parameter over the wide range of FIO2 levels encountered clinically.


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