Assessing the Impact of Hands-Free Georgia on Serious Motor Vehicle Accidents

BACKGROUND

Hands-Free Georgia Law (HB673) was designed to prevent motor vehicle collisions (MVCs) by banning drivers from using their hands for non-driving-related activities, including cell phone use. We investigate HB673 effect on trauma activations secondary to MVCs in Georgia.

METHODS

The Georgia Trauma Registry (GTR) was queried for MVCs from 2017 to 2019, representing the 18 months prior and following implementation of HB673. The number of MVCs for each period and severity of MVC designated by the average injury severity score (ISS) for each trauma activation were collected.

RESULTS

Prior to implementation, a total of 43 080 traumas were recorded in GTR, 11 111 (25.8%) were attributed to an MVC. Following implementation, 12 130 (23.6%) occurred secondary to MVCs. Statewide MVC-related traumas per 1000 residents increased from 1.07 to 1.14 with increased mortality rate and unchanged median ISS per MVC.

CONCLUSIONS

The Hands-Free Georgia Law seems to have not had a major reduction in mortality in its early implementation.

The impact of hypertonic saline on damage control laparotomy after penetrating abdominal trauma

PURPOSE

The inability to achieve primary fascial closure (PFC) after emergency laparotomy increases the rates of adverse outcomes including fistula formation, incisional hernia, and intraabdominal infection. Hypertonic saline (HTS) infusion improves early PFC rates and decreases time to PFC in patients undergoing damage control laparotomy (DCL) after injury. We hypothesized that in patients undergoing DCL after penetrating abdominal injury, HTS infusion would decrease the time to fascial closure as well as the volume of crystalloid required for resuscitation without inducing clinically relevant acute kidney injury (AKI) or electrolyte derangements.

METHODS

We retrospectively analyzed all penetrating abdominal injury patients undergoing DCL within the University of Pennsylvania Health System (January 2015-December 2018). We compared patients who received 3% HTS at 30 mL/h (HTS) to those receiving isotonic fluid (ISO) for resuscitation while the abdominal fascia remained open. Primary outcomes were the rate of early PFC (PFC within 72 h) and time to PFC; secondary outcomes included acute kidney injury, sodium derangement, ventilator-free days, hospital length of stay (LOS), and ICU LOS. Intergroup comparisons occurred by ANOVA and Tukey's comparison, and student's t, and Fischer's exact tests, as appropriate. A Shapiro-Wilk test was performed to determine normality of distribution.

RESULTS

Fifty-seven patients underwent DCL after penetrating abdominal injury (ISO n = 41, HTS n = 16). There were no significant intergroup differences in baseline characteristics or injury severity score. Mean time to fascial closure was significantly shorter in HTS (36.37 h ± 14.21 vs 59.05 h ± 50.75, p = 0.02), and the PFC rate was significantly higher in HTS (100% vs 73%, p = 0.01). Mean 24-h fluid and 48-h fluid totals were significantly less in HTS versus ISO (24 h: 5.2L ± 1.7 vs 8.6L ± 2.2, p = 0.01; 48 h: 1.3L ± 1.1 vs 2.6L ± 2.2, p = 0.008). During the first 72 h, peak sodium (Na) concentration (146.2 mEq/L ± 2.94 vs 142.8 mEq/L ± 3.67, p = 0.0017) as well as change in Na from ICU admission (5.1 mEq/L vs 2.3, p = 0.016) were significantly higher in HTS compared to ISO. Patients in the HTS group received significantly more blood in the trauma bay compared to ISO. There were no intergroup differences in intraoperative blood transfusion volume, AKI incidence, change in chloride concentration (△Cl) from ICU admit, Na to Cl gradient (Na:Cl), initial serum creatinine (Cr), peak post-operative Cr, change in creatinine concentration (△Cr) from ICU admission, creatinine clearance (CrCl), initial serum potassium (K), peak ICU K, change in K from ICU admission, initial pH, highest or lowest post-operative pH, mean hospital LOS, ICU LOS, and ventilator-free days.

CONCLUSIONS

HTS infusion in patients undergoing DCL after penetrating abdominal injury decreases the time to fascial closure and led to 100% early PFC. HTS infusion also decreased resuscitative fluid volume without causing significant AKI or electrolyte derangement. HTS appears to offer a safe and effective fluid management approach in patients who sustain penetrating abdominal injury and DCL to support early PFC without inducing measurable harm.

LEVEL OF EVIDENCE

Level III.

Abstract P337: Src Signaling and Toll-like Receptor 4 (TLR4) are Involved in Ouabain-induced Endothelial Cell Inflammation

Controversial evidence indicates that endogenous ouabain, a cardiotonic steroid can be synthesized in the adrenal cortex and hypothalamus and secreted as a hormone reaching nanomolar concentrations in the blood. The steroid has pathophysiological significance since its blood levels are positively correlated with blood pressure elevation. Inflammation of the vascular wall and endothelial dysfunction contribute to vascular stiffening in hypertension and it has been proposed that the endothelium is a site of action of ouabain. We hypothesized that ouabain would increase pro-inflammatory events in the endothelium. We observed that a low concentration ouabain (10nM; 24hr) sharply increased mRNA levels of the pro-inflammatory cytokines compared to control group (vehicle; 24h), TNF-α (59.9 fold vs con), IL-1β (3.23 fold vs con), COX2 (309.08 fold vs con), IL-6 (5.76 fold vs con) in cultured, human aortic endothelial cell (HAEC) and increased cyclooxygenase (COX2) expression (1.78 fold vs con). Simultaneously, a burst of nitric oxide (NO) was produced (1.2 fold vs con). Thus, low nanomolar concentrations of ouabain induced endothelial cell inflammation and dysfunction. Additionally, we observed that ouabain (10nM; 24hr) decreased mRNA expression of epidermal growth factor receptor (EGFR) (0.31 fold decrease vs con), and decreased the protein expression of EGFR (0.23 fold decrease vs con). But we found that ouabain induced the expression of non-receptor tyrosine kinase Src (2.27 fold vs con) and Toll-like receptor 4 (TLR4) (2.03 fold vs con), and activated the downstream signaling molecules, Myd88 (1.69 fold vs con), Akt (P-AKT/AKT, 4.31 fold vs con). Overall, the results provide a mechanism for ouabain-induced endothelial cell inflammation involving the inhibition of EGFR and the activation of Src and TLR4 to induce Akt signaling leading to secretion of pro-inflammatory cytokines.

Abstract P132: Everolimus, a Targeted Cancer Therapy, Improves Endothelium Dependent Relaxation in Spontaneously Hypertensive Rat Mesenteric Arteries

Cardiovascular disease is the leading cause of death in cancer survivors. The short-term and long-term cardiotoxic effects of targeted chemotherapeutics is not well known. Everolimus, an inhibitor to mammalian target of rapamycin (mTOR) complex 1, is a targeted therapy approved for the treatment of metastatic breast, colon, renal cell and pancreatic cancer. Clinical retrospective reviews suggest heart failure and hypertension as cardiotoxic effects of everolimus. Our lab previously showed that everolimus exposure on normotensive vessels increased sensitivity to adrenergic stimuli in a time and concentration dependent manner. We hypothesized that everolimus leads to enhanced contractility and impaired relaxation in hypertensive vessels. We studied the effects of everolimus on the contractility and relaxation of mesenteric resistance arteries (MRA) of male Wistar rats (12-15 weeks old, n=4) and spontaneously hypertensive rats (SHR) (15-18 weeks old, n=2) on a wire myograph. Two concentrations of everolimus were evaluated, 0.1μM and 0.1nM, during a one-hour incubation. Normotensive MRA exposed to everolimus (0.1μM) showed a decreased contractile response to phenylephrine (LogEC50 + SEM, Ctrl:-5.627 + 0.07 vs Drug: -5.390 + 0.10) but no difference when exposed to 0.1nM. SHR MRA showed no difference in PE-induced contraction at 0.1μM (LogEC50 + SEM, Ctrl:-5.638 + 0.08 vs Drug:-6.286 + 0.36) or 0.1nM (LogEC50 + SEM, Ctrl:-5.638 + 0.08 vs Drug:-5.332 + 0.16). No differences were observed in endothelium dependent relaxation response to acetylcholine (ACh) for either drug concentration in the normotensive vessels; however, SHR MRA exhibited enhanced sensitivity to ACh with everolimus exposure (LogEC50 + SEM, Ctrl: -6.851 + 0.15 vs Drug:-9.233 + 0.37 at 0.1nM; LogEC50 + SEM, Ctrl: -6.851 + 0.15 vs Drug:-8.244 + 0.34 at 0.1μM). Our data show that everolimus affects contractility in normotensive vessels, while affecting the dilatory response in SHR vessels with an improvement in endothelium-dependent relaxation. Everolimus may be a good therapeutic agent for hypertensive cancer patients. However, long term treatments with this targeted therapy need to be evaluated for vascular dysfunction induction, which could be associated with cardiotoxicity.

Abstract P523: Time and Concentration Dependent Vascular Changes of Cancer Therapy Everolimus in Mesenteric Resistance Arteries

The leading cause of death in cancer survivors is cardiovascular disease, in part due to cancer therapy-induced cardiotoxicity. The short- and long-term cardiovascular side effects of a newer class of targeted chemotherapy, mTOR inhibitors, have not been well established as they have been with anthracyclines, anti-VEGF therapy and tyrosine kinase inhibitors. mTOR inhibitor Everolimus, used as an agent in transplant immunosuppression, is now indicated for the treatment of metastatic breast, colon, renal cell and pancreatic cancer. Retrospective clinical data indicate the possibility of heart failure and hypertension as cardiotoxic effects of Everolimus, although data are inconclusive and no vascular function studies are available. We studied the effects of Everolimus on the contractility and relaxation of mesenteric resistance arteries (MRA) of male Wistar rats (12-15 weeks old) at different drug incubation time frames (1, 12, and 24 hours) on a tension wire myograph. We hypothesized that the longer exposure to Everolimus (i.e. longer incubation time) leads to enhanced contractility to phenylephrine (PE) and impaired relaxation to acetylcholine (ACh). Two concentrations of Everolimus were evaluated, 0.1 μM and 0.1 nM. MRA exposed to Everolimus 0.1 μM showed a decreased contractile response to PE at 1 hour incubation (LogEC 50 , Ctrl: -5.627±0.07 vs. Drug: -5.390±0.10, *p=0.03) and at 12 hours incubation (LogEC 50 , Ctrl: -5.295±0.16 vs. Drug: -5.645±0.08, *p=0.04), while no difference was observed at 24 hours (p>0.05). MRA exposed to Everolimus 0.1 nM for 24 hours showed enhanced contractility to PE (LogEC 50 , Ctrl: -5.295±0.16 vs. Drug=-5.740±0.07, *p=0.005) while no difference at 1 hour or 12 hour incubation times (p>0.05). No differences were observed in the endothelium-dependent relaxation response to ACh for either drug concentration or any of the incubation times. Our data suggest that the effects of Everolimus on resistance arteries from normotensive rats are a time and concentration-dependent: short-term incubation (i.e., < 12hours) increases sensitivity of MRA to adrenergic stimuli. However, long-term treatment with this drug may lead to vascular dysfunction, which could be associated with cardiotoxicity observed in cancer survivals.

Abstract P525: Mtor Inhibitor Everolimus Decreases Aortic Sensitivity To Phenylephrine In Normotensive Rats

While targeted chemotherapeutics have improved cancer clinical outcomes, many of these agents have the drawback of cardiovascular complications. It has been established that the mTOR complexes have a pivotal role in many types of cancer, promoting cell growth, proliferation, and survival. Inhibitors of this pathway such as first generation Everolimus, and second generation PP242, have inhibited cancer cell proliferation and cancer progression. When compared with other target chemotherapeutics such as VEGF and tyrosine kinase inhibitors, first generation mTOR inhibitors have demonstrated decreased incidence of cardiovascular complications, however the specific vascular effects of mTOR inhibitors have not been investigated. Therefore, Everolimus, an inhibitor of mTORC1, and PP242, an inhibitor of mTORC1 and mTORC2, were evaluated for their effects on vascular reactivity of rat aorta. Previous studies have demonstrated that mTORC2 displayed cardioprotective effects. Therefore, we hypothesize that Everolimus, which does not inhibit mTORC2, will have a decreased contractile response to Phenylephrine (PE) and increased Acetylcholine (Ach)-induced relaxation. On the contrary, since PP242 inhibits mTORC2, we hypothesize that PP242 will increase contractile response to PE, and will decrease ACh-induced relaxation. Concentration response curves to PE (1nM - 30μM), and Ach (1nM - 30μM) were conducted in isolated aortic rings from male normotensive Wistar rats (12-15 weeks old) on a pin myograph ex vivo after 1 hour of incubation with each drug. Aortic rings treated with 31 μM of Everolimus showed decreased sensitivity to PE (LogEC 50 = -7.322 ±0.078 vs. treated: -6.578 ± 0.1116 p<0.05). No differences were observed in the contractile responses to PE for Everolimus (0.1 nM) or PP242 (245 nM) (p>0.05). Similarly, no differences were observed in the endothelium-dependent relaxation response to Ach for all three treatments. These results suggest that Everolimus may be a good therapeutic choice for cancer patients also suffering from cardiovascular dysfunction.