Apparent complete pneumothorax in the presence of lung sliding.

SESSION TITLE: Pleural Case Report PostersSESSION TYPE: Case Report PosterPRESENTED ON: Sunday, March 23, 2014 at 01:15 PM - 02:15 PMINTRODUCTION: Lung sliding (LS), visceral pleura moving against parietal pleura, is a lung ultrasound (LU) finding that rules out a complete pneumothorax (PTX) (1). We present a case of apparent complete left PTX in the presence of LS.

CASE PRESENTATION: A 90 year old female treated for lower extremity cellulitis and recurrent urinary tract infections was admitted to the SICU with acute hypercapnic respiratory failure, pulmonary edema, and sepsis requiring volume control ventilation. The CXR showed bilateral mild alveolar edema and basilar pleural effusions left > right. Initial LU revealed a moderate L sided effusion, without septation. On ICU day 6, the AM CXR revealed what appeared to be a striking left sided complete PTX which radiology urgently reported to the ICU. Reexamination revealed the patient to be hemodynamically stable without evidence of markedly asymmetric breath sounds, subcutaneous emphysema, or elevated peak airway pressures. LU revealed b/l LS, an unchanged moderate left sided pleural effusion, and multiple B-lines b/l without lung point. A chest tube was not placed. Repeat CXR 3 hours later showed no PTX. Re-review of the AM CXR revealed faint lung markings peripheral to the apparent pleural line which also extended beyond the confines of the lung.

DISCUSSION: CXR is less sensitive, but more specific than LU in the diagnosis of PTX. CXR vs. LU: sensitivity 28% vs. 86% and specificity 100% vs. 97% (2, 3). A lack of LS may result from conditions other than PTX (e.g., pleural fibrosis) and evidence of PTX clearly seen on CXR, is more specific for PTX than absent LS. On the other hand, the presence of LS rules out a complete PTX since there is no point at which there is apposition of the pleura to create LS. In this case the CXR demonstrated what appeared to be a complete PTX, but LU demonstrated both LS and B -lines - either of which rule out complete PTX. In the setting of an equivocal CXR, LU can rapidly help to differentiate a true vs. false PTX. In this case, the respiratory and hemodynamic stability argued against a PTX, however there are cases where instability can make the diagnosis very challenging.

CONCLUSIONS: LU is useful technique for evaluation of the pleural abnormalities at the bedside. It improves the accuracy of the physical examination and enables a better understanding of pleural pathology than the plain CXR alone.Reference #1: Lichtenstein D, et al. Intensive Care Med (1998) 24: 1331-1334Reference #2: American Journal of Emergency Medicine (2012) 30, 485-488Reference #3: Zhang M et al. Crit Care 2006. 10 R112.

DISCLOSURE: The following authors have nothing to disclose: Rafael Alba Yunen, John Oropello, Andrew LeibowitzNo Product/Research Disclosure Information.