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Background Hypocalcemia is common in patients admitted to the surgical intensive care unit and is associated with increased morbidity and mortality. Current dosing strategies do not always achieve ionized calcium (iCa) normalization, especially in patients with severe hypocalcemia. Objective The purpose of this study was to explore the association between intravenous (IV) calcium dose and change in ionized calcium. Setting Patients admitted to the surgical intensive care unit with concomitant hypocalcemia at a large academic hospital in the United States. Method This single center, retrospective cohort study evaluated the association between IV calcium dose and subsequent change in ionized calcium level in adult surgical intensive care unit patients with hypocalcemia. The primary outcome of this study was to develop a model exploring the association between IV calcium dose and change in iCa levels. Secondary outcomes included describing the average IV calcium dose required to normalize iCa levels, average time to normalization of iCa levels, and assessing the safety of IV calcium replacement. Main outcome measure Change in iCa. Results One hundred and ninety-four patients met study criteria. In the final model initial iCa level, total calcium dose, the interaction between initial iCa level and total calcium dose, age, and pancreatitis remained. The model (R2 = 0.625) is expressed by the following equation: Change in iCa level = 0.462 - 0.011 × [Ca dose] - 0.0007 × [Age] - 0.259 × [Initial iCa] + 0.076 × [initial iCa × Ca dose] - 0.076 × [Pancreatitis]. Removing two patients that received > 10 grams of total calcium improved the R2 to 0.769. Lastly, a simplified model removing age and pancreatitis found a similar R2 of 0.756. Conclusion We observed that change in iCa level after initial calcium dose depended on the baseline iCa. Our full and simplified model excluding two outliers predicted 76.9% and 75.6% of the variation in iCa response, respectively. If validated in other settings this model could be utilized to provide more accurate calcium dosing.

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BACKGROUND: Nonoperative management (NOM) of most liver injury (LI) compromises teaching of technical skills required for intraoperative LI hemostasis. This study assesses this void. METHODS: The records of patients (pts) admitted for LI during two years (1/1/16-12/31/17) were compared to pts treated during two-year intervals for the last six decades. Treatment included NOM, operation only (OR/only), suture (Sut), tractotomy (Tra), dearterialization (HAL), and resection (Res). RESULTS: During 2016/2017, 41 pts had penetrating (23) or blunt (18) LI. Treatment for penetrating LI was NOM (4), OR/only (12), and hemostasis (7) with Sut (3), HAL (1), Tra (1), and Res (2). Treatment for blunt LI was NOM (16) and OR/only (2). 14 residents performed an average of 0.5 procedures. During six decades, LI requiring hemostasis was 121, 114, 30, 48, 17, and 7 per decade. Concomitantly, the percent having NOM or OR/only was 46%, 47%, 62%, 59%, 72%, and 83%. CONCLUSION: NOM precludes adequate training for hemostasis of LI. Technical proficiency for LI hemostasis requires training in Advanced Trauma Operative Management (ATOM), Advanced Surgical Skills for Exposure in Trauma (ASSET), and rotation through a liver transplant or hepatobiliary service.

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The spatial resolution of a conventional imaging laser radar system is constrained by the diffraction limit of the telescope's aperture. We investigate a technique known as synthetic-aperture imaging laser radar (SAIL), which employs aperture synthesis with coherent laser radar to overcome the diffraction limit and achieve fine-resolution, long-range, two-dimensional imaging with modest aperture diameters. We detail our laboratory-scale SAIL testbed, digital signal-processing techniques, and image results. In particular, we report what we believe to be the first optical synthetic-aperture image of a fixed, diffusely scattering target with a moving aperture. A number of fine-resolution, well-focused SAIL images are shown, including both retroreflecting and diffuse scattering targets, with a comparison of resolution between real-aperture imaging and synthetic-aperture imaging. A general digital signal-processing solution to the laser waveform instability problem is described and demonstrated, involving both new algorithms and hardware elements. These algorithms are primarily data driven, without a priori knowledge of waveform and sensor position, representing a crucial step in developing a robust imaging system.