The Relationship between Serum Sodium, Serum Osmolality, and Intracranial Pressure in Patients with Traumatic Brain Injury Treated with Hyperosmolar Therapy.

BACKGROUND: Treatment of elevated intracranial pressure (ICP) in traumatic brain injury (TBI) is controversial. Hyperosmolar therapy is used to prevent cerebral edema in these patients. Many intensivists measure direct correlates of these agents-serum sodium and osmolality. We seek to provide context on the utility of using these measures to estimate ICP in TBI patients. MATERIALS AND METHODS: Patients admitted with TBI who required ICP monitoring from 2008 to 2012 were included. Intracranial pressure, serum sodium, and serum osmolality were assessed prior to hyperosmotic therapy then at 6, 12, 18, 24, 48, and 72 hours after admission. A linear regression was performed on sodium, osmolality, and ICP at baseline and serum sodium and osmolality that corresponded with ICP for 6-72-hour time points. RESULTS: 136 patients were identified. Patients with initial measures were included in the baseline analysis (n = 29). Patients who underwent a craniectomy were excluded from the 6-72-hour analysis (n = 53). Initial ICP and serum sodium were not significantly correlated (R2 .00367, P = .696). Initial ICP and serum osmolality were not significantly correlated (R2 .00734, P = .665). Intracranial pressure and serum sodium 6-72 hours after presentation were poorly correlated (R2 .104, P < .0001), as were ICP and serum osmolality at 6-72 hours after presentation (R2 .116, P < .0001). DISCUSSION: Our results indicate initial ICP is not correlated with serum sodium or osmolality suggesting these are not useful initial clinical markers for ICP estimation. The association between ICP and serum sodium and osmolality after hyperosmolar therapy was poor, thus may not be useful as surrogates for direct ICP measurements.

Unexpected Diaphragmatic Hernia Among Patients Undergoing Video-Assisted Thoracic Surgery for Internal Fixation of Rib Fractures.

Traumatic blunt diaphragm injuries are a diagnostic challenge in trauma. They may be missed due to the increasing trend of non-operative management of patients. The purpose of this study was to review the rate of occult blunt diaphragm injuries in patients who underwent video assisted thoracic surgery (VATS) for rib fixation. This retrospective study included patients that received VATS as part of our institutional protocol for rib fracture management. This includes utilizing incentive spirometry, multimodal analgesia, and early consideration for VATS. Data was abstracted from the electronic medical record and included demographics, operative findings, and outcomes. Thirty patients received VATS per our rib fracture protocol. No patients had any identified diaphragm injury on pre-operative imaging. A concomitant diaphragm injury was identified in 20% (6/30) of the study population. All patients were alive at 30 days. For all patients, total hospital length of stay was 14.5 days, ICU length of stay was 8.9 days, and average ventilator days was 4.2 days. When comparing patients with and without concomitant diaphragm injuries, hospital length of stay was 16.8 days vs. 14.5 (P = 0.59), ICU length of stay was 11.8 days vs. 8.2 (P = 0.54), and ventilator days was 4.5 days vs. 4.2 (P = 0.93). This study revealed that 20% of patients undergoing VATS for rib fracture fixation had a concomitant diaphragm injury. This higher-than-expected prevalence suggests that groups of patients sustaining blunt trauma may have occult diaphragmatic injuries that are otherwise unidentified. This raises the need for improved diagnostic modalities to identify these injuries.