from Section 1 - Cardiovascular and respiratory disorders
Published online by Cambridge University Press: 19 October 2009
Adult respiratory distress syndrome
Epidemiology
Adult respiratory distress syndrome (ARDS) is a severe form of acute respiratory failure that can develop following a systemic or pulmonary insult. Adult respiratory distress syndrome is not unique to adults, and in children is known as “acute respiratory distress syndrome”. The incidence of ARDS in pregnancy is variably reported as 1 in 3000 to 1 in 6000 deliveries with mortality as high as 44%.
Etiology
Several disorders can cause ARDS in pregnancy (see Table 4.1). Sepsis, secondary to pyelonephritis, chorioamnionitis, or endometritis, is a common cause of ARDS in pregnancy. Other causes include obstetric hemorrhage, severe preeclampsia, and aspiration. There may be a combination of sepsis, shock, and fluid overload, the latter of which can be exacerbated by tocolytic therapy.
Pathophysiology
Following the initial insult, a number of inflammatory mediators such as tumor necrosis factor and interleukins 1, 6, and 8 are released. Neutrophils are activated to release other mediators such as reactive oxygen (O2) species and proteases. These mediators produce widespread microvascular and alveolar epithelial damage. Microvascular damage leads to increased capillary permeability and subsequent interstitial and alveolar edema. Alveolar damage results in loss of surfactant and subsequent alveolar collapse. Alveolar edema and collapse contribute to ventilation–perfusion (V/Q) mismatching and intrapulmonary shunting with subsequent hypoxemia.
Pulmonary hypertension frequently develops leading to right ventricular (RV) dysfunction which reduces left ventricular (LV) preload and cardiac output (CO). Depressed CO further compromises O2 delivery.
To save this book to your Kindle, first ensure [email protected] is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Find out more about the Kindle Personal Document Service.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.