Early Identification of Patients Who Will Meet 24-Hour Fluid Output Threshold for Chest Tube Removal After Lung Resection.

Improving evidence-based chest tube removal may reduce the length of stay following surgery. Presently, most chest tube removal protocols include a fluid output threshold based on a 24-hour observation period. The purpose of this study was to evaluate if, within a 24-hour time period, fluid output measurements at 6, 8, and 12 hours could predict if the total 24-hour fluid output would comply with a predetermined volume threshold considered acceptable for safe chest tube removal. Following lung resection, pleural fluid output data were prospectively recorded by a digital drainage system and analyzed retrospectively. Twenty-four-hour fluid output was calculated from every available 6-, 8-, and 12-hour measurement and compared to set 24-hour output criteria for chest tube removal (ie, 400 mL, 250 mL, and 20% of whole-body lymphatic flow). Performance of interim fluid outputs in predicting whether 24-hour fluid output criteria were satisfied was measured. From 2015 to 2018, 150 patients had digital pleural fluid drainage data suitable for analysis. Performance of interim fluid output data in identifying which patients would satisfy 24-hour output criteria ranged from 85% (95% confidence interval [CI] = 83-86) to 94% (95% CI = 93-94) for specificity, 75% (95% CI = 73-76) to 92% (95% CI = 90-93) for positive predictive value, and 6% (95% CI = 6-7) to 15% (95% CI = 14-17) for false-positive rate. Potential time saved in duration of drainage using interim fluid output data ranged from 10 to 16 hours. Pleural fluid output measured for 6-, 8-, and 12-hour durations can accurately identify patients who will meet 24-hour fluid output threshold for safe chest tube removal.

Forecasting pulmonary air leak duration following lung surgery using transpleural airflow data from a digital pleural drainage device.

BACKGROUND: Prolonged air leak (PAL) is often the limiting factor for hospital discharge after lung surgery. Our goal was to develop a statistical model that reliably predicts pulmonary air leak resolution by applying statistical time series modeling and forecasting techniques to digital drainage data. METHODS: Autoregressive Integrated Moving Average (ARIMA) modeling was used to forecast air leak flow from transplural air flow data. The results from ARIMA were retrospectively internally validated with a group of 100 patients who underwent lung resection between December 2012 and March 2017, for whom digital pleural drainage data was available for analysis and a persistent air leak was the limiting factor for chest tube removal. RESULTS: The ARIMA model correctly identified 82% (82/100) of patients as to whether or not the last chest tube removal was appropriate. The performance characteristics of the model in properly identifying patients whose air leak would resolve and who would therefore be candidates for safe chest tube removal were: sensitivity 80% (95% CI, 69-88%), specificity 88% (95% CI, 68-97%), positive predictive value 95% (95% CI, 86-99%), and negative predictive value 59% (95% CI, 42-79%). The false positive and false negative rate was 12% (95% CI, 12-31%) and 20% (95% CI, 12-31%). CONCLUSIONS: We were able to validate a statistical model that that reliably predicted resolution of pulmonary air leak resolution over a 24-hour period. This information may improve the care of patients with chest tube by optimizing duration of pleural drainage.

Characterization of the four isomers of (123)I-CMICE-013: a potential SPECT myocardial perfusion imaging agent.

UNLABELLED: Myocardial perfusion imaging (MPI) with single photon emission computed tomography (SPECT) is widely used in the assessment of coronary artery disease (CAD). We have developed (123)I-CMICE-013 based on rotenone, a mitochondrial complex I (MC-1) inhibitor, as a promising new MPI agent. Our synthesis results in a mixture of four species of (123)I-CMICE-013 A, B, C, D. In this study, we separated the four species and evaluated their biodistribution and imaging properties. The cold analogs (127)I-CMICE-013 A, B, C, D were isolated and characterized and their chemical structures proposed. METHODS: (123)I-CMICE-013 was synthesized by radiolabeling rotenone with Na(123)I in trifluoroacetic acid (TFA) with iodogen as the oxidizing agent at 60°C for 45min, and the four species were separated by RP-HPLC. The cold analogs (127)I-CMICE-013 A, B, C and D were isolated with a similar procedure and characterized by NMR and mass spectrometry. Biodistribution and microSPECT imaging studies were carried out on normal rats. RESULTS: We propose the mechanism of the rotenone iodination and the structures of the four species. First, I(+) forms an intermediate three-membered ring with 6' and 7' carbons. Second, the lone electron pair of the water molecule attacks the 6' or 7'-carbon, following by the formation of 6'-OH, and 7'-I bonds as in major products C and D, or 6'-I and 7'-OH bonds as in minor products A and B. The weaker 6'-I bond in the intermediate prompts the nucleophilic attachment of water at the favorable 6'-carbon to generate C and D. MicroSPECT images of (123)I-CMICE-013 A, B, C, D in rats showed clear visualization of myocardium and little interference from lung and liver. The imaging time activity curves and biodistribution data showed complex profiles for the four isomers, which is not expected from the structure activity relationship theory. CONCLUSION: (123/127)I-CMICE-013 A and B are constitutional isomers with C and D, while A and C are diastereomers of B and D, respectively. Overall, the biological characteristics of the four species are not correlated perfectly with their molecular structures.