Point-of-Care Ultrasound (POCUS) for the Cardiothoracic Anesthesiologist

Point-of-Care Ultrasound (POCUS) is a valuable bedside diagnostic tool for a variety of expeditious clinical assessments or as guidance for a multitude of acute care procedures. Varying aspects of nearly all organ systems can be evaluated using POCUS and, with the increasing availability of affordable ultrasound systems over the past decade, many now refer to POCUS as the 21^st-century stethoscope. With the current available and growing evidence for the clinical value of POCUS, its utility across the perioperative arena adds enormous benefit to clinical decision-making. Cardiothoracic anesthesiologists routinely have used portable ultrasound systems for nearly as long as the technology has been available, making POCUS applications a natural extension of existing cardiothoracic anesthesia practice. This narrative review presents a broad discussion of the utility of POCUS for the cardiothoracic anesthesiologist in varying perioperative contexts, including the preoperative clinic, the operating room (OR), intensive care unit (ICU), and others. Furthermore, POCUS-related education, competence, and certification are addressed.

COVID-19-Related Cardiovascular Disease and Practical Considerations for Perioperative Clinicians

Coronavirus disease 2019 (COVID-19) has a clinical course predominated by acute respiratory failure due to viral pneumonia with possible acute respiratory distress syndrome. However, nearly one third of infected patients, especially those with preexisting cardiovascular (CV) disease, are reported to present with some combination of acute cardiac injury, myocarditis, heart failure, cardiogenic shock, or significant dysrhythmias. In addition, COVID-19 infections are also associated with high rates of thromboembolic and disseminated intravascular coagulation complications. Severe myocarditis and heart failure have both been reported as the initial presenting conditions in COVID-19 infection. This review highlights the important considerations related to the CV manifestations of COVID-19 infections, describes the mechanisms and clinical presentation of CV injury, and provides practical management and therapy suggestions. This narrative review is based primarily on the multiple case series and cohorts from the largest initial COVID-19 outbreak centers (ie, Wuhan, China, and Italy); hence, nearly all presented data and findings are retrospective in nature with the attendant limitations of such reports.

Impact of Isolyte Versus 0.9% Saline on Postoperative Event of Acute Kidney Injury Assayed by Urinary [TIMP-2] × [IGFBP7] in Patients Undergoing Cardiac Surgery

OBJECTIVE

Administration of excess chloride in 0.9% normal saline (NS) decreases renal perfusion and glomerular filtration rate, thereby increasing the risk for acute kidney injury (AKI). In this study, the effect of NS versus Isolyte use during cardiac surgery on urinary levels of tissue inhibitor of metalloproteinase 2 and insulin-like growth factor-binding protein 7 [TIMP-2] × [IGFBP7] and postoperative risk of AKI were examined.

DESIGN

Prospective, randomized, and single-blinded trial.

SETTING

Single university medical center.

PARTICIPANTS

Thirty patients over 18 years without chronic renal insufficiency or recent AKI undergoing elective cardiac surgery.

INTERVENTIONS

Subjects were randomized to receive either NS or Isolyte during the intraoperative period.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was the change in urinary levels of [TIMP2] × [IGFBP7] from before surgery to 24 hours postoperatively. Secondary outcomes included serum creatinine pre- and postoperatively at 24 and 48 hours, serum chloride pre- and postoperatively at 24 and 48 hours, need for dialysis prior to discharge, and arterial pH measured 24 hours postoperatively. Sixteen patients received NS and 14 patients received Isolyte. Three patients developed AKI within the first 3 postoperative days, all in the NS group. The authors found increases in [TIMP-2] × [IGFBP7] in both groups. However, the difference in this increase between study arms was not significant (p = 0.92; -0.097 to 0.107).

CONCLUSION

The authors observed no change in urinary [TIMP-] × [IGFBP7] levels in patients receiving NS versus Isolyte during cardiac surgery. Future larger studies in patients at higher risk for AKI are recommended to evaluate the impact of high- versus lower-chloride solutions on the risk of postoperative AKI after cardiac surgery.

Atypical echocardiographic findings in traumatic aortic transection

Aortic rupture and transection are constituents of the acute aortic syndrome. Injury to the thoracic aorta during motor vehicle crashes is associated with blunt chest trauma and rapid deceleration mechanisms. Type A dissections and/or rupture of the aorta at the level of the aortic isthmus are the more common presentations of aortic injuries associated with motor vehicle crashes. We present the case of atypical echocardiographic findings of a nearly complete circumferential transection of the proximal ascending aorta injury after a motorcycle crash.

The effect of surgical stress on the endotoxin-induced interferon-gamma response

Most animal studies of cytokine release during sepsis or endotoxemia have used models in which studies are performed during or immediately after surgical stress. In a previous study, we showed that surgical stress as measured by elevated endogenous corticosterone concentrations attenuated the endotoxin-induced tumor necrosis factor alpha (TNFalpha) response. To determine whether surgical stress attenuates the endotoxin-induced interferon-gamma (IFN-gamma) response, chronically catheterized male Sprague-Dawley rats were treated with endotoxin 10 microg/kg immediately after surgery for catheter placement (surgical stress group, SS group) or at least 4 days postoperative (nonstressed group, NS group). We found that peak endotoxin-induced IFN-gamma responses were similar in the SS and NS groups (2094 +/- 315 pg/mL vs. 1863 +/- 307 pg/mL). Baseline corticosterone concentrations were significantly elevated in the SS group compared to the NS group (273.8 +/- 15.2 ng/mL vs. 30.0 +/- 8.5 ng/mL, P < 0.001). Peak TNFalpha concentrations were significantly reduced in the SS group compared to the NS group (5.2 +/- 1.9 ng/mL vs. 69.9 +/- 10.3 ng/mL, P = 0.0002). While peak serum TNFalpha concentrations were inversely related to baseline corticosterone concentrations, there was no correlation between peak IFN-gamma concentrations and baseline corticosterone concentrations or between TNFalpha and IFN-gamma concentrations. We conclude that surgical stress associated with elevated concentrations of endogenous corticosterone does not attenuate the endotoxin-induced IFN-gamma response despite an attenuation of the endotoxin-induced TNFalpha response. Because the effect of stress on different cytokines is varied, studies of sepsis and endotoxemia must account for the effects of experimentally-induced stress on cytokine responses.