AUTOMATICALLY APPLIED VENTILATOR TIDAL VOLUME AND FREQUENCY BASED ON BODY WEIGHT PROVIDES APPROPRIATE ARTERIAL BLOOD GAS EXCHANGE: A VALIDATION STUDY

2002 ◽  
Vol 30 (Supplement) ◽  
pp. A88
Author(s):  
Michael J Banner
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Benjamin Gaston ◽  
Santhosh M. Baby ◽  
Walter J. May ◽  
Alex P. Young ◽  
Alan Grossfield ◽  
...  

AbstractWe have identified thiolesters that reverse the negative effects of opioids on breathing without compromising antinociception. Here we report the effects of d-cystine diethyl ester (d-cystine diEE) or d-cystine dimethyl ester (d-cystine diME) on morphine-induced changes in ventilation, arterial-blood gas chemistry, A-a gradient (index of gas-exchange in the lungs) and antinociception in freely moving rats. Injection of morphine (10 mg/kg, IV) elicited negative effects on breathing (e.g., depression of tidal volume, minute ventilation, peak inspiratory flow, and inspiratory drive). Subsequent injection of d-cystine diEE (500 μmol/kg, IV) elicited an immediate and sustained reversal of these effects of morphine. Injection of morphine (10 mg/kg, IV) also elicited pronounced decreases in arterial blood pH, pO2 and sO2 accompanied by pronounced increases in pCO2 (all indicative of a decrease in ventilatory drive) and A-a gradient (mismatch in ventilation-perfusion in the lungs). These effects of morphine were reversed in an immediate and sustained fashion by d-cystine diME (500 μmol/kg, IV). Finally, the duration of morphine (5 and 10 mg/kg, IV) antinociception was augmented by d-cystine diEE. d-cystine diEE and d-cystine diME may be clinically useful agents that can effectively reverse the negative effects of morphine on breathing and gas-exchange in the lungs while promoting antinociception. Our study suggests that the d-cystine thiolesters are able to differentially modulate the intracellular signaling cascades that mediate morphine-induced ventilatory depression as opposed to those that mediate morphine-induced antinociception and sedation.


2020 ◽  
Vol 29 (158) ◽  
pp. 190171
Author(s):  
Marlies van Dijk ◽  
Karin Klooster ◽  
Nick H.T. Ten Hacken ◽  
Frank Sciurba ◽  
Huib. A.M. Kerstjens ◽  
...  

Lung volume reduction (LVR) treatment in patients with severe emphysema has been shown to have a positive effect on hyperinflation, expiratory flow, exercise capacity and quality of life. However, the effects on diffusing capacity of the lungs and gas exchange are less clear. In this review, the possible mechanisms by which LVR treatment can affect diffusing capacity of the lung for carbon monoxide (DLCO) and arterial gas parameters are discussed, the use of DLCO in LVR treatment is evaluated and other diagnostic techniques reflecting diffusing capacity and regional ventilation (V′)/perfusion (Q′) mismatch are considered.A systematic review of the literature was performed for studies reporting on DLCO and arterial blood gas parameters before and after LVR surgery or endoscopic LVR with endobronchial valves (EBV). DLCO after these LVR treatments improved (40 studies, n=1855) and the mean absolute change from baseline in % predicted DLCO was +5.7% (range −4.6% to +29%), with no real change in blood gas parameters. Improvement in V′ inhomogeneity and V′/Q′ mismatch are plausible explanations for the improvement in DLCO after LVR treatment.


1990 ◽  
Vol 10 (1) ◽  
pp. 56-59 ◽  
Author(s):  
A Robichaud

The diagnosis of alteration in gas exchange related to body position requires a deliberate evaluation of PaO2 responses. Body positions that improve V/Q matching and thus PaO2 need to be specified in patient care plans; individualized interventions are more useful than generic care plans that state, "turn q 2 h." Additionally, standard rotations for patients treated on mechanically rotating beds could be individualized according to gas exchange responses to the position changes. Routine documentation of patient body positions next to arterial blood gas results on flow sheets could prove valuable in the evaluation and treatment of hypoxemia in patients with pulmonary problems.


2014 ◽  
Vol 45 (1) ◽  
pp. 227-243 ◽  
Author(s):  
Peter D. Wagner

The field of pulmonary gas exchange is mature, with the basic principles developed more than 60 years ago. Arterial blood gas measurements (tensions and concentrations of O2and CO2) constitute a mainstay of clinical care to assess the degree of pulmonary gas exchange abnormality. However, the factors that dictate arterial blood gas values are often multifactorial and complex, with six different causes of hypoxaemia (inspiratory hypoxia, hypoventilation, ventilation/perfusion inequality, diffusion limitation, shunting and reduced mixed venous oxygenation) contributing variably to the arterial O2and CO2tension in any given patient. Blood gas values are then usually further affected by the body's abilities to compensate for gas exchange disturbances by three tactics (greater O2extraction, increasing ventilation and increasing cardiac output). This article explains the basic principles of gas exchange in health, mechanisms of altered gas exchange in disease, how the body compensates for abnormal gas exchange, and based on these principles, the tools available to interpret blood gas data and, quantitatively, to best understand the physiological state of each patient. This understanding is important because therapeutic intervention to improve abnormal gas exchange in any given patient needs to be based on the particular physiological mechanisms affecting gas exchange in that patient.


1984 ◽  
Vol 32 (1) ◽  
pp. 1 ◽  
Author(s):  
P Greenaway

Gill area increased with increasing body size in Holthuisana transversa (area in square millimetres equals 1946 times mass, in grams, to the power of 0.563). The increase in area was largely due to increase in the area of individual lamellae, at least over the size range studied (10-35 g). The area of the lungs was only 10% ofthe area ofthe gills but potentially these were at least as effective in gas exchange, due to their much shorter blood-gas diffusion distance. The volume of the lungs increased with body weight (volume in millilitres equals 0.043 times mass, in grams, to the power of 1.218), whilst tidal volume increased at a lower rate (tidal volume in millilitres equals 0.082 times mass to the power of 0.831) in the crabs examined (3-36 g).


2008 ◽  
Vol 32 (1) ◽  
pp. 61-64 ◽  
Author(s):  
Kent S. Kapitan

Students often have difficulty understanding the relationship of O2 consumption, CO2 production, cardiac output, and distribution of ventilation-perfusion ratios in the lung to the final arterial blood gas composition. To overcome this difficulty, I have developed an interactive computer simulation of pulmonary gas exchange that is web based and allows the student to vary multiple factors simultaneously and observe the final effect on the arterial blood gas composition (available at www.siumed.edu/medicine/pulm/vqmodeling.htm ). In this article, the underlying mathematics of the computer model is presented, as is the teaching strategy. The simulation is applied to a typical clinical case drawn from the intensive care unit to demonstrate the interdependence of the above factors as well as the less-appreciated importance of the Bohr and Haldane effects in clinical pulmonary medicine. The use of a computer to vary the many interacting factors involved in the arterial blood gas composition appeals to today's students and demonstrates the importance of basic physiology to the actual practice of medicine.


2012 ◽  
Vol 113 (4) ◽  
pp. 541-548 ◽  
Author(s):  
Tracey L. Bryan ◽  
Sean van Diepen ◽  
Mohit Bhutani ◽  
Miriam Shanks ◽  
Robert C. Welsh ◽  
...  

The development of intrapulmonary shunts with increased cardiac output during exercise in healthy humans has been reported in several recent studies, but mechanisms governing their recruitment remain unclear. Dobutamine and dopamine are inotropes commonly used to augment cardiac output; however, both can increase venous admixture/shunt fraction (Qs/Qt). It is possible that, as with exercise, intrapulmonary shunts are recruited with increased cardiac output during dobutamine and/or dopamine infusion that may contribute to the observed increase in Qs/Qt. The purpose of this study was to examine how dobutamine and dopamine affect intrapulmonary shunt and gas exchange. Nine resting healthy subjects received serial infusions of dobutamine and dopamine at incremental doses under normoxic and hyperoxic (inspired O2fraction = 1.0) conditions. At each step, alveolar-to-arterial Po2difference (A-aDo2) and Qs/Qt were calculated from arterial blood gas samples, intrapulmonary shunt was evaluated using contrast echocardiography, and cardiac output was calculated by Doppler echocardiography. Both dobutamine and dopamine increased cardiac output and Qs/Qt. Intrapulmonary shunt developed in most subjects with both drugs and paralleled the increase in Qs/Qt. A-aDo2was unchanged due to a concurrent rise in mixed venous oxygen content. Hyperoxia consistently eliminated intrapulmonary shunt. These findings contribute to our present understanding of the mechanisms governing recruitment of these intrapulmonary shunts as well as their impact on gas exchange. In addition, given the deleterious effect on Qs/Qt and the risk of neurological complications with intrapulmonary shunts, these findings could have important implications for use of dobutamine and dopamine in the clinical setting.


2021 ◽  
Author(s):  
Ben Gaston ◽  
Santhosh M. Baby ◽  
Walter J. May ◽  
Alex P. Young ◽  
Alan Grossfield ◽  
...  

Abstract We have identified thiolesters that reverse the negative effects of opioids on breathing without compromising analgesia. Here we report the effects of D-cystine diethyl ester (D-cystine diEE) or D-cystine dimethyl ester (D-cystine diME) on morphine-induced changes in ventilation, arterial-blood gas chemistry, A-a gradient (index of gas-exchange in the lungs) and analgesia in freely moving rats. Injection of morphine (10 mg/kg, IV) elicited negative effects on breathing (e.g., depression of tidal volume, minute ventilation, peak inspiratory flow, and inspiratory drive). Subsequent injection of D-cystine diEE (500 mmol/kg, IV) elicited an immediate and sustained reversal of these effects of morphine. Injection of morphine (10 mg/kg, IV) also elicited pronounced decreases in arterial blood pH, pO2 and sO2 accompanied by pronounced increases in pCO2 (all indicative of a decrease in ventilatory drive) and A-a gradient (mismatch in ventilation-perfusion in the lungs). These effects of morphine were reversed in an immediate and sustained fashion by D-cystine diME (500 mmol/kg, IV). Finally, the duration of morphine (5 and 10 mg/kg, IV) analgesia was augmented by D-cystine diEE. D-cystine diEE and D-cystine diME may be clinically useful agents that can effectively reverse the negative effects of morphine on breathing and gas-exchange in the lungs while promoting analgesia.


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