medigraphic.com
ISSN 2448-8909 (Print)

2014, Number 4

<< Back Next >>

Med Crit 2014; 28 (4)

Sensitivity, specificity and predictive values of two formulas for calculating pulmonary shunts

Gorordo DLA, Morales SMAM, Calzada MCC, Domínguez MA

Language: Spanish
References: 31
Page: 239-244
PDF size: 194.21 Kb.


ABSTRACT

Introduction: There are several physiological mechanisms by which decreases the amount of oxygen inspired oxygen ratio reaches the tissues through the circulation when these mechanisms is out of control, they become a problem for the patient. Understanding the pathophysiology of shunts is just the first step, there are several methods to calculate the fraction of pulmonary shunts, this paper presents two alternative equations to the conventional method, comparing with the conventional method, the sensitivity, specificity and predictive values.
Objective: To compare the sensitivity, specificity and predictive values of Dominguez’s and Gorordo’s linear formula against the conventional method.
Methodology: This is an observational, retrospective, analytical study, chart review was performed according to the inclusion criteria, was compared calculated the pulmonary shunts by the conventional method, Dominguez’s and Gorordo’s, to establish the sensitivity, specificity and predictive values of the two alternative to the standard equation.
Results: The calculation of significance for non-parametric tests were performed using the Kruskal-Wallis test, finding no significant difference at p = 0.713 between the conventional method and the two proposed equations, the sensitivity of the conventional formula is 98%, while alternative methods obtained 95.6 and 97.4%, a 55% specificity and 50 versus 16.6%, the positive predictive value is 0.92 against 0.847 and 0.904, the negative predictive value was 0.50 versus 0.44 and 0.80.
Conclusion: Not statistically significant between the three methods for calculating pulmonary shunts difference was found, so both can be used instead the conventional method.


REFERENCES

  1. Berggren SM. The oxygen deficit of arterial blood caused by non-ventilated parts of the lung. Acta Physiol Scand. 1942;4(Suppl. 11):492-515.

  2. Riley RL, Cournand A. “Ideal” alveolar air and the analysis of ventilation-perfusion relationships in the lungs. J Appl Physiol. 1948;1(12):825-847.

  3. Ravin MB, Epstein RM, Malm JR. Contribution of the thebesian veins to the physiologic shunt in anesthetized man. J Appl Physiol. 1965;20:1148-1152.

  4. Vogiatzis I, Zakynthinos S, Boushel R, Athanasopoulos D, Guenette JA, et al. The contribution of intrapulmonary shunts to the alveolar-to-arterial oxygen difference during exercise is very small. J Physiol. 2008;586(9):2381-2391.

  5. Riley RL, Cournanc A. Analysis of factors affecting partial pressures of oxygen and carbon dioxide in gas and blood of lungs: theory. J Appl Physiol. 1951;4:77-101.

  6. Riley RL, Permutt S. Venous admixture component of the AaPO2 gradient. J Appl Physiol. 1973;35:430-431.

  7. McIntyre RW, Laws AK, Ramachandran PR. Positive expiratory pressure plateau: improved gas exchange during mechanical ventilation. Can Anaesth Soc J. 1969;16(6):477-486.

  8. Gattinoni L, Pesenti A, Bombino M, Baglioni S, Rivolta M, et al. Relationships between lung computed tomographic density, gas exchange, and PEEP in acute respiratory failure. Anesthesiology. 1988;69(6):824-832.

  9. Shapiro BA, Cane RD, Harrison RA, Steiner MC. Changes in intrapulmonary shunting with administration of 100 percent oxygen. Chest. 1980;77(2):138-141.

  10. White RI. Pulmonary arteriovenous malformations: how do we diagnose them and why is it important to do so? Radiology. 1992;182:633-635.

  11. Thompson RD, Jackson J, Peters M, Doré CJ, Hughes MB. Sensitivity and specificity of radioisotope right-left shunt measurements and pulse oximetry for early detection of pulmonary arteriovenous malformations. Chest. 1999;155(1):109-113.

  12. Chiang ST. A normogram for venous shunt (Qs/Qt) calculation. Thorax. 1968;23:563-565.

  13. Cane RD, Shapiro BA, Harrison RA. Minimizing errors in intrapulmonary shunt calculations. Crit Care Med. 1980;8:294-297.

  14. Chilvers ER, Peters AM, George P, Hughes JMB, Allison DJ. Quantification of right to left shunt through pulmonary arteriovenous malformations using 99Tcm albumin microspheres. Clinical Radiology. 1988;39(6):611-614.

  15. El-Khatib MF, Jamaleddine GW. A new oxygenation index for reflecting intrapulmonary shunting in patients undergoing open-heart surgery. Chest. 2004;125:592-596.

  16. Lovering AT, Stickland MK, Amann M, Murphy JC, O’Brien MJ, Hokanson JS, et al. Hyperoxia prevents exercise-induced intrapulmonary arteriovenous shunt in healthy humans. J Physiol. 2008;586(18):4559-4565.

  17. Strickland MK, Welsh RC, Haykowsky MJ, Petersen SR, Anderson WD, Taylor DA. Intrapulmonary shunt and pulmonary gas exchange during exercise in humans. J Physiol. 2004;561(1):321-329.

  18. Casthely PA, Lear S, Cottrell JE, Lear E. Intrapulmonary shunting during induced hypotension. Anesthesia and Analgesia. 1982;61(3):231-235.

  19. Torre A. Manifestaciones pulmonares de las hepatopatías. Rev Gastroenterol Mex. 2003;68(Supl. 2):35-42.

  20. Gurung P, Goldblatt M, Huggins JT, Doelken P, Nietert PJ, Sahn SA. Pleural fluid analysis and radiographic, sonographic, and echocardiographic characteristics of hepatic hydrothorax. Chest. 2011;140(2):448-453.

  21. Arguedas MR, Abrams GA, Krowka MJ, Fallon MB. Prospective evaluation of outcomes and predictors of mortality in patients with hepatopulmonary syndrome undergoing liver transplantation. Hepatology. 2003;37(1):192-197.

  22. Neumann P, Hegenstierna G. Ventilation-perfusion distributions in different porcine lung injuty models. Acta Anaesthesiol Scand. 2001;45:78-86.

  23. Abdallah EA, Waked E, Metwaly A, Khalek AA. The role of arterio-venous shunt in the pathogenesis of pulmonary hypertension in patients with end-stage renal disease. Kidney. 2010;19:239-243.

  24. Kumar A, Falke KJ, Geffin B, Aldredge CF, Laver MB, Lowenstein E, et al. Continuous positive-pressure ventilation in acute respiratory failure. N Engl J Med. 1970;238(26):1430-1436.

  25. Reinprecht A, Greher M, Wolfsberger S, Dietrich W, Illevich UM, Gruber A. Prone position in subarachnoid hemorrhage patients with acute respiratory distress syndrome: effects on cerebral tissue oxygenation and intracranial pressure. Crit Care Med. 2003;31(6):1931-1938.

  26. Walmrath D, Pilch J, Scharmann M, Grimminger F, Seeger W. Severe VA/Q mismatch in perfused lungs evoked by sequential challenge with endotoxin and E. coli hemolysin. Journal of Applied Physiology. 1994;76(3):1020-1030.

  27. Mure M, Domino KB, Kindahl SG, Hlastal MP, Altemeier WA, Glanny RW. Regional ventilation-perfusion distribution is more uniform in the prone position. J Appl Physiol. 2000;88(3):1076-1083.

  28. Argiriou M, Mikroulis D, Sakellaridis T, Didilis V, Papalios A, Bougiukas G. Acute pressure overload of the right ventricle. Comparison of two models of right-left shunt. Pulmonary artery to left atrium and right atrium to left atrium: experimental study. J Cardiotoracic Surgery. 2011;6(143):1-10.

  29. Posadas JG, Ugarte A, Domínguez G. El pulmón y el corazón en el enfermo con ventilación mecánica. Rev Asoc Mex Med Crit. 2004;18(2):59-62.

  30. Casthely PA, Lear S, Cottrell JE, Lear E. Intrapulmonary shunting during induced hypotension. Anesthesia and Analgesia. 1982;61(3):231-235.

  31. Galie N, Manes A, Palazzini M, Negro L, Marinelli A, Gambetti S, et al. Management of pulmonary arterial hypertension associated with congenital systemic to pulmonary shunts and Eisenmenger’s syndrome. Drugs. 2008;68(8):1049-1066.




2020     |     www.medigraphic.com