Purpose of review: We will briefly review the classification of shock and the hallmark features of each subtype. Available modalities for monitoring shock patients will be discussed, along with evidence supporting the use, common pitfalls, and practical considerations of each method.
Recent findings: As older, invasive monitoring methods such as the pulmonary artery catheter have fallen out of favor, newer technologies for cardiac output estimation, echocardiography, and noninvasive tests such as passive leg raising have gained popularity. Newer forms of minimally invasive or noninvasive monitoring (such as pulse contour analysis and chest bioreactance) show promise but will need further investigation before they are considered validated for practical use. There remains no 'ideal' test or standard of care for cardiopulmonary monitoring of shock patients.
Summary: Shock has potentially reversible causes of morbidity and mortality if appropriately diagnosed and managed. Older methods of invasive monitoring have significant limitations but are still critical for managing shock in certain patients and settings. Newer methods are easier to employ, but further validation is needed. Multiple modalities along with careful clinical assessment are often useful in distinguishing shock subtypes. Best practice standards for monitoring should be based on institutional expertise.