Blunt Aortic / Inferior Vena Cava Injury: Are We Consistently Providing the Same Level of Care?

Major vascular traumatic injuries have a higher pre-hospital and in-hospital mortality rate. The different mechanisms of injury and anatomy of the aorta and inferior vena cava (IVC) make the management a constant challenge to surgeons and clinicians. Blunt traumatic aortic injury (BTAI) can occur at the thoracic or abdominal level, each of which possesses different considerations. Blunt traumatic inferior vena cava injury (BTIVCI) also has important diagnostic challenges since the lesion may not be as evident in the IVC as compared to the aorta, possibly due to lower caval pressures or the ability to self-tamponade from adjacent structures. Endovascular management has significantly increased in the past years, and despite an improvement in mortality, the approach to aortic and IVC injuries is not well standardized. Diagnostic imaging helps to classify the extent of the lesions and guide towards the best therapeutic options for each case. Conservative management, in some cases, has shown to reduce mortality, and close follow-up has proven good outcomes. Future research will provide more evidence to determine the best approach to BTAI and BTIVCI for better long-term outcomes. This article aims to provide an updated review of the current literature regarding diagnosis, classification, and management of BTAI and BTIVCI.

I Want My Bullet Back: Percutaneous Endovascular Removal of a Right Atrial Foreign Body

The incidence and prevalence of firearm-related homicide in the United States make headlines daily. As a result, an epidemic of penetrating injuries is on the rise. Specifically, foreign bodies such as bullets and shrapnel are usually left inside the human body due to penetrating injuries, unless they are in close proximity to vital structures. We present a case of a bullet within the right atrial chamber of the heart, which was successfully removed by a minimally invasive endovascular approach.

Predicting Central Venous Pressure by Measuring Femoral Venous Diameter Using Ultrasonography

Objectives

The objective of this exploratory study was to find out the correlation of femoral vein diameter (FVD) to central venous pressure (CVP) measurements and to derive a prediction equation to help ascertain the fluid volume status in a critical patient.

Patients and methods

This was a single-centered prospective cohort study designed and conducted by the critical care department of Shifa International hospital in Islamabad, Pakistan. Patients were enrolled from the medical and surgical intensive care units. The inclusion criteria consisted of patients > 18 years of age, and an intrathoracic central venous catheterization (CVC) in place for producing CVP waveform through the transducer. Patients having contraindications to CVP placement and those unable to lie supine were excluded from the study. Critical Care fellows with sufficient training in performing venous ultrasonography measured the FVD. They were blinded to the CVP values of the same patients.

Results

The study included 108 patients. Among these 70/108 (64.8%) were males. Mean age was 53.85 (SD=16.74). The CVP and femoral vein diameter were measured in all patients. Mean CVP was 9.89 cmH2O (SD=3.46) and mean femoral vein diameter was 0.92 cm (SD=0.27). Multiple regression was used to generate a prediction model. FVD, age and sex of the patient were used as predictor variables to predict CVP diameter. The model was statistically significant with a p-value of < 0.000 and an F-value of 104.806. R-squared value for this model came out to be 0.744, thus the model was able to explain about 74.4% of the variance in the values observed for CVP. When controlled for age and sex, FVD was found highly correlated with CVP diameter with a p-value of < 0.000. A regression equation was derived that can be used to generate predicted values of CVP in millimeters of mercury with an R-square of 0.745 if FVD in centimeters is provided; CVP (cmH2O) = -0.039 + 10.718* FVD.

Conclusions

FVD was found highly correlated to CVP measurements and it suggests an alternate non-invasive method of ascertaining the volume status in the critically ill.

Effects of a 28-day cage-change interval on intracage ammonia levels, nasal histology, and perceived welfare of CD1 mice

We measured daily intracage ammonia levels and performed weekly assessments of CD1 male, female, and breeder mice housed within disposable, ventilated cages that remained unchanged for 28 d. We tested housing groups comprising 1, 3, or 5 sex-matched mice per cage and breeder pairs with litters. Mice housed in cages with higher concentrations of ammonia developed degeneration and inflammatory lesions in the nasal passages. Mean ammonia exposure levels that caused rhinitis were 181 ppm for 18 d. Ammonia exposures of 93 ppm for 16 d caused necrosis of the olfactory epithelium, whereas 52 ppm for 13 d caused epithelial degeneration. Observers could not detect visible signs of rhinitis or identify cages with elevated ammonia levels, nor did they identify any sick or distressed mice. Observers consistently assigned poorer welfare scores as cages became dirtier. We conclude that we can extend the cage-change interval to at least 28 d for disposable, ventilated caging housing a single CD1 mouse. Cages containing 3 CD1 mice of either sex should be changed biweekly, and cages containing 5 CD1 mice or breeder pairs should be changed at least once weekly.

Growing male rats in individually ventilated and open-top cages

During the past few decades, the development and use of individually ventilated cages (IVC), which are now commercially available for housing laboratory mice and rats, have increased. Because limited information is available regarding the influence of caging systems on the growth of rats, the present study assessed body weight and food and water consumption in growing male rats that were housed in IVC and open-top cages (OTC). We allocated 21-d-old male Wistar outbred rats (HsdOla:WI; n = 24) into 2 groups, which then were housed in pairs in IVC (n = 12) and OTC (n = 12). After an 8-d acclimatization period, body weight and food and water consumption were assessed every 3 d until the rats were 94 d old. There were no significant differences between the body weights of rats housed in IVC compared with OTC over the 65-d observation period. Food and water consumption were greater in rats housed in OTC compared with IVC, becoming significantly different when the rats were 50 and 53 d old, respectively. In conclusion, IVC and OTC housing conditions influenced food and water intakes but not body weight in growing male rats. Further research is needed to clarify the exact basis for these changes in food and water consumption.