Publications by authors named "Joshua Livingston"

7 Publications

  • Page 1 of 1

Computed Tomography Appearance of the "Whirlpool Sign" in Ovarian Torsion.

Clin Pract Cases Emerg Med 2021 Nov;5(4):468-469

University of California, Irvine, Department of Emergency Medicine, Orange, California.

Case Presentation: A 28-year-old female presented to the emergency department complaining of right lower abdominal pain. A contrast-enhanced computed tomography (CT) was done, which showed a 15-centimeter right adnexal cyst with adjacent "whirlpool sign" concerning for right ovarian torsion. Transvaginal pelvic ultrasound (US) revealed a hemorrhagic cyst in the right adnexa, with duplex Doppler identifying arterial and venous flow in both ovaries. Laparoscopic surgery confirmed right ovarian torsion with an attached cystic mass, and a right salpingo-oophorectomy was performed given the mass was suspicious for malignancy.

Discussion: Ultrasound is the test of choice for diagnosis of torsion due to its ability to evaluate anatomy and perfusion. When ovarian pathology is on the patient's right, appendicitis is high in the differential diagnosis, and CT may be obtained first. Here we describe a case where CT first accurately diagnosed ovarian torsion by demonstrating the whirlpool sign, despite an US that showed arterial flow to the ovary. Future studies should determine whether CT alone is sufficient to diagnose or exclude ovarian torsion.
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November 2021

No Difference in Mortality Between Level I and II Trauma Centers for Combined Burn and Trauma.

J Surg Res 2020 12 13;256:528-535. Epub 2020 Aug 13.

Department of Surgery, University of California Irvine, Orange, California. Electronic address:

Background: Trauma patients with burn injuries have higher morbidity and mortality rates compared with patients who solely experience burn or trauma injuries. There is a paucity of data regarding burn-trauma (BT) patient outcomes at level I (LI) trauma centers compared with level II (LII) centers. We hypothesized that BT patients at LI trauma centers have lower mortality rates than those at LII trauma centers.

Methods: The Trauma Quality Improvement Program (2010-2016) was queried for patients aged ≥18 y who had BT injuries. Patients treated at an LI were compared with those at an LII center with a primary outcome of in-hospital mortality. Secondary outcomes included hospital length of stay (LOS) and intensive care unit (ICU) LOS. A multivariable logistic regression analysis was used to identify factors associated with all-cause mortality.

Results: From 1971 BT patients, 1540 (78%) were treated at an LI trauma center, and 431 (22%) at an LII center. Compared with LII centers, LI BT patients had a longer median LOS (10 versus 7 d; P < 0.001) and ICU LOS (5 versus 4 d; P < 0.001). Both LI and LII centers had similar mortality rates (8.5% versus 7.0%; P = 0.300). On multivariable analysis, receiving care at an LI trauma center was not associated with decreased mortality (odds ratio 0.79, 95% confidence interval 0.42-1.48; P = 0.456).

Conclusions: We report that LI trauma center BT patients had an increased hospital and ICU LOS compared with those at LII centers. However, there was no significant difference in mortality between patients cared for at LI and LII trauma centers in risk-adjusted models.
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December 2020

pH-Responsive Copolymer Films Prepared by Surface-Initiated Polymerization and Simple Modification.

Langmuir 2020 Jan 17;36(3):715-722. Epub 2020 Jan 17.

Department of Chemical and Biomolecular Engineering , Vanderbilt University , Nashville , Tennessee , 37205.

We report the preparation of pH-responsive, ester/carboxylic acid random copolymer films via simple modification of poly(norbornene diacyl chloride) (pNBDAC), prepared via surface-initiated ring-opening metathesis polymerization, with mixtures of water and ethanol to form carboxylic acid and ethyl ester side groups. The pNBDAC film serves as a compositionally versatile platform to controllably obtain copolymers with multiple functionalities. In modifying the pNBDAC to form the copolymer film, ethanol exhibits a significantly higher reactivity with acyl chloride groups within the film than does water. The magnitude and range of the pH-responsive performance are highly dependent on the carboxylic acid content in the copolymer films, which demonstrates the effect of film hydrophilicity on the pH-responsive switching of ionic barrier properties. The resistance of the film against ion transfer can be decreased by a factor of 10 through pH change, demonstrating pH-induced switching from hydrophobic and insulating to swollen and ion-permeable films. The interactions of the copolymer films with water at different pH values were also explored. When the copolymer contains 34% carboxylic acids, a 4× greater film thickness is obtained in high pH solution than in low pH solution due to ionically driven water swelling. The reversibility of the pH-responsive performance of these copolymer films is high based on measurements using quartz crystal microbalance with dissipation (QCM-D).
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January 2020

Assessment of clinical dehydration using point of care ultrasound for pediatric patients in rural Panama.

World J Emerg Med 2019 ;10(1):46-50

Department of Emergency Medicine, University of California Irvine, Orange, CA 92868, USA.

Background: Dehydration and its associated symptoms are among the most common chief complaints of children in rural Panama. Previous studies have shown that intravascular volume correlates to the ratio of the diameters of the inferior vena cava (IVC) to the aorta (Ao). Our study aims to determine if medical students can detect pediatric dehydration using ultrasound on patients in rural Panama.

Methods: This was a prospective, observational study conducted in the Bocas del Toro region of rural Panama. Children between the ages of 1 to 15 years presenting with diarrhea, vomiting, or parasitic infection were enrolled in the study. Ultrasound measurements of the diameters of the IVC and abdominal aorta were taken to assess for dehydration.

Results: A total of 59 patients were enrolled in this study. Twenty-four patients were clinically diagnosed with dehydration and 35 were classified to have normal hydration status. Of the 24 patients with dehydration, half (=12) of these patients had an IVC/Ao ratio below the American threshold of 0.8. Of the remaining asymptomatic subjects, about half (=18) of these subjects also had an IVC/Ao ratio below the American threshold of 0.8.

Conclusion: Our study did not support previous literature showing that the IVC/Ao ratio is lower in children with dehydration. It is possible that the American standard for evaluating clinical dehydration is not compatible with the rural pediatric populations of Panama.
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January 2019

National analysis of testicular and scrotal trauma in the USA.

Res Rep Urol 2018 10;10:51-56. Epub 2018 Aug 10.

Division of Trauma, Burns and Surgical Critical Care, Department of Surgery, University of California, Irvine, Orange County, CA, USA,

Background: To provide a descriptive analysis of scrotal and testicular trauma in the USA. Additionally, we hypothesized that motorcycle collision would have a higher association with scrotal or testicular trauma and subsequent scrotal or testicular operation, compared to a bicycle collision.

Methods: The National Trauma Data Bank (2007-2015) was queried to identify adult male patients with scrotal or testicular trauma. A multivariable logistic regression analysis was performed.

Results: A total of 8,030 patients (0.23%) had scrotal/testicular injury, with 44.6% involved in blunt trauma. A penetrating mechanism occurred in 50.5% of cases, with assault by firearm (75.8%) being the most common. The median age of the patients was 31 years and the median injury severity score was 8. Most had isolated scrotal or testicular trauma (74.5%), with 48.3% requiring scrotal or testicular operation, most commonly repair of laceration (37.3%). Patients involved in a motorcycle collision had higher risk for scrotal/testicular trauma (OR=5.40, CI=4.40-6.61, =0.0004) and subsequent scrotal/testicular surgery (OR=4.93, CI=3.82-6.36, =0.0005), compared to bicycle collision.

Conclusion: Scrotal or testicular trauma is rare but occurs most commonly after assault by firearm. Most patients only have isolated scrotal or testicular trauma, but nearly half require subsequent scrotal or testicular operation. Trauma patients presenting after a motorcycle collision have a higher association of scrotal or testicular trauma and subsequent surgery when compared to those involved in a bicycle collision.
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August 2018

National risk factors for blunt cardiac injury: Hemopneumothorax is the strongest predictor.

Am J Surg 2019 04 25;217(4):639-642. Epub 2018 Jul 25.

University of California, Irvine, Department of Surgery, Division of Trauma, Burns and Surgical Critical Care, Orange, CA, USA.

Background: Blunt cardiac injury (BCI) can occur after chest trauma and may be associated with sternal fracture (SF). We hypothesized that injuries demonstrating a higher transmission of force to the thorax, such as thoracic aortic injury (TAI), would have a higher association with BCI.

Methods: We queried the National Trauma Data Bank (NTDB) from 2007-2015 to identify adult blunt trauma patients.

Results: BCI occurred in 15,976 patients (0.3%). SF had a higher association with BCI (OR = 5.52, CI = 5.32-5.73, p < 0.001) compared to TAI (OR = 4.82, CI = 4.50-5.17, p < 0.001). However, the strongest independent predictor was hemopneumothorax (OR = 9.53, CI = 7.80-11.65, p < 0.001) followed by SF and esophageal injury (OR = 5.47, CI = 4.05-7.40, p < 0.001).

Conclusion: SF after blunt trauma is more strongly associated with BCI compared to TAI. However, hemopneumothorax is the strongest predictor of BCI. We propose all patients presenting after blunt chest trauma with high-risk features including hemopneumothorax, sternal fracture, esophagus injury, and TAI be screened for BCI.

Summary: Using the National Trauma Data Bank, sternal fracture is more strongly associated with blunt cardiac injury than blunt thoracic aortic injury. However, hemopneumothorax was the strongest predictor.
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April 2019

Feasibility study of minimally trained medical students using the Rural Obstetrical Ultrasound Triage Exam (ROUTE) in rural Panama.

World J Emerg Med 2018 ;9(3):216-222

Department of Emergency Medicine, University of California Irvine, Orange, CA 92868, USA.

Background: Maternal and infant mortality rates reported in rural Panama are greater than those in urban regions. Bocas del Toro is a region of Panama inhabited by indigenous people at greater risk for pregnancy-related complications and deaths due to geographic isolation and limited access to health care. Portable ultrasound training programs have recently been implemented in low-resource settings to increase access to diagnostic imaging. The goal of this study is to determine the feasibility of teaching first-year medical students the Rural Obstetrical Ultrasound Triage Exam (ROUTE) to help identify pathology in pregnant women of the Bocas del Toro region of Panama.

Methods: Eight first-year medical students completed ROUTE training sessions. After training, the students were compared to professional sonographers to evaluate their accuracy in performing the ROUTE. Students then performed the ROUTE in mobile clinics within Bocas del Toro. They enrolled women pregnant in their 2nd or 3rd trimesters and measured biparietal diameter, head circumference, amniotic fluid index, fetal lie and placental position. Any abnormal measurement would be further analyzed by the lead physician for a potential hospital referral.

Results: A total of 60 women were enrolled in the study. Four women were detected as having a possible high-risk pregnancy and thus referred to a hospital for further evaluation.

Conclusion: Based on our data, first-year medical students with additional training can use the ROUTE to identify complications in pregnancy using ultrasound in rural Panama. Additional studies are required to determine the optimal amount of training required for proficiency.
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January 2018