Nurse-performed ultrasound assessment of gastric residual volume and enteral nasogastric tube placement in the general intensive care unit.

OBJECTIVE: Ultrasonography is an essential imaging modality in the critical care population and has been increasingly utilized to check gastric residual volume . Various studies have shown that intensive care unit nurses untrained in ultrasound can easily be trained in its accurate interpretation. We prospectively analyzed nurse-performed repeated measurements of gastric residual volume and nasogastric tube positioning via an ultrasound technique in the intensive care unit. DESIGN: This was a single-center, cross-sectional prospective study. Four intensive care unit nurses, evenly divided into two groups (teams A and B), underwent four hours of formal ultrasound training by three critical care staff physicians. The trained nurses provided bedside ultrasound assessments of gastric residual volume and nasogastric tube positioning which were compared to a standard protocol of syringe aspiration. RESULTS: Ninety patients were recruited to the study. Four measurements per patient were performed, for a total of 360 assessments. The ultrasound gastric residual volume assessments were correlated with the syringe aspiration protocol and demonstrated high Intraclass Correlation Coefficient rates of 0.814 (0.61-0.92) for team A and 0.85 (0.58-0.91) for team B. Nasogastric tube placement was successfully and independently verified by ultrasound in most of the critically ill patients (78% of team A and 70% of team B). The comparative ultrasound assessments of tube positioning demonstrated good correlation of 0.733 (0.51-0.88) between each team's two independent observers. CONCLUSION: Our study demonstrated a strong correlation between US utilization for assessment of gastric residual volume and nasogastric tube positioning and standard protocol methods, suggesting it is a safe, simple and effective practice for intensive care unit nurses.

Cell-free DNA--a marker to predict ischemic brain damage in a rat stroke experimental model.

BACKGROUND: The animal model of stroke that is most frequently used is a rat model of focal brain ischemia caused by middle cerebral artery occlusion (MCAO). Several studies have reported a link between levels of cell-free DNA (CFD) and neurologic outcome in human stroke. The purpose of this study was to assess brain injury and measure CFD levels in 2 models of MCAO in rats, and to determine whether brain injury correlates with CFD. METHODS: A total of 60 rats were used for this study. Twenty rats underwent a sham procedure, 20 rats had MCAO using a monofilament, and 20 rats had MCAO with a silicon-coated filament. Groups were further divided into 2 subgroups. In 1 subgroup of 10 rats, neurologic performance [measured as a neurologic severity score, (NSS)] was measured at 1 and 24 hours after the procedure, and brain edema and infarct volume were determined at 24 hours. In the second subgroup of 10 rats, CFD was measured at 0, 1, 2, 4, 8, 12, and 24 hours and at 2, 3, 4, and 5 days. Neurologic performance (measured as a NSS) was measured at 1 and 24 hours after the procedure. RESULTS: The main finding was a significant increase in CFD levels observed 24 hours after the onset of MCAO. The correlation between the total infarct volume and CFD levels of the 3 groups was R=0.78, P<0.0001. Brain edema and NSS also were strongly correlated with CFD levels at 24 hours after MCAO (R=0.91, P<0.0001 and R=0.73, P<0.0001, respectively). CONCLUSIONS: We found that CFD levels correlate well with the extent of ischemic injury, brain edema, and neurologic outcome in rats 24 hours post-MCAO. We have also shown that CFD correlates well with the expected temporal progression of ischemic injury. These findings place CFD in a unique place as a biomarker for stroke, both experimentally and possibly clinically.