Ala S. Haddadin

Perioperative Management of Patients With Left Ventricular Assist Devices Undergoing Noncardiac Surgery

t d p t l ACCORDING TO THE American Heart Association 2010 update, more than 5.7 million people in the United States uffer from heart failure.1-3 The prevalence of heart failure in the United States has been rising with the aging population. The annual number of heart failure–related hospitalizations has risen to more than 1 million and has resulted in combined direct and indirect costs approximating

Utility of ultrasound in the ICU.

40 billion.1,2 Despite adancements in the pharmacologic management of heart failure, ortality rates have remained relatively unchanged. After a iagnosis of heart failure, the 1-year mortality rate is 20%,1 and nce a patient has American College of Cardiology/American eart Association stage D heart failure (ie, end-stage heart ailure), the 2-year mortality rate approaches 75%.4 Although ardiac transplantation has excellent results for the treatment of nd-stage heart failure, this option is limited severely by the umber of available donor organs, with the annual number of eart transplants having plateaued at approximately 2,300 over he last 15 years. In 1991, since the landmark Randomized valuation of Mechanical Assistance of Chronic Heart Failure REMATCH) trial showed improved 1and 2-year survival ates in the mechanical circulatory support group versus the edical management group,5 left ventricular assist devices (LVADs) have taken a more prominent role in the management of heart failure. Since 2006 when the Interagency Registry for Mechanically Assisted Circulatory Support started collecting data on mechanical circulatory support devices, more than 3,000 primary adult LVADs have been implanted.6 Parides et al7 estimated that between 20,000 and 60,000 patients could enefit from LVAD therapy annually.

Surgical repair of pulmonary artery dissection

Purpose of review Use of ultrasound in the acute care setting has become more common in recent years. However, it still remains underutilized in the perioperative management of critical patients. In this review, we aim to increase the awareness of ultrasound as an important diagnostic modality that can be used in the perioperative period to improve patient care. Our main focus will be in describing the diagnostic uses of ultrasound to identify cardiac, pulmonary, airway and vascular diseases commonly encountered in acute care settings. Recent findings We find that ultrasound can be used in a quick fashion to assess a haemodynamically unstable patient. Protocols are available to use ultrasound as a part of cardiopulmonary resuscitation. Ultrasound can help in deciding fluid vs. pressor treatment by evaluating the inferior vena cava and other cardiac structures. Lung ultrasound can not only help in diagnosing pneumothoracies and effusions but also look at lung recruitment and diaphragmatic movement, hence can aid in deciding extubation strategies. This modality can be utilized for confirmation of endotracheal tube. Recent interest in axillary vein cannulation with ultrasound guidance has gained some momentum. Summary This article covers the recent developments and literature available on point of care ultrasound and its utilization in the perioperative period. We have not covered some other important uses of ultrasound such as abdominal examination looking at the aorta and other abdominal organs. This was beyond the scope of this article.

Activation of complement factor B contributes to murine and human myocardial ischemia/reperfusion injury

Fig. 1. (a) Contrast-enhanced axial computed tomography image at the level of the PA bifurcation demonstrating the dissection flap within the main PA (arrow). (b) Three-dimensional reconstruction of the computed tomography images demonstrating the dissection flap within the main PA (arrow). (c) Intraoperative trans-oesophageal echocardiography showing the main PA with a 5.18 cm diameter and a dissection flap (arrow). (d) Intra-operative epiarterial ultrasound of the main PA showing the dissection flap (arrow).

Evaluation of Hemostasis by the Clot Signature Analyzer: A Potentially Valuable Device for the Anesthesiologist

The pathophysiology of myocardial injury that results from cardiac ischemia and reperfusion (I/R) is incompletely understood. Experimental evidence from murine models indicates that innate immune mechanisms including complement activation via the classical and lectin pathways are crucial. Whether factor B (fB), a component of the alternative complement pathway required for amplification of complement cascade activation, participates in the pathophysiology of myocardial I/R injury has not been addressed. We induced regional myocardial I/R injury by transient coronary ligation in WT C57BL/6 mice, a manipulation that resulted in marked myocardial necrosis associated with activation of fB protein and myocardial deposition of C3 activation products. In contrast, in fB-/- mice, the same procedure resulted in significantly reduced myocardial necrosis (% ventricular tissue necrotic; fB-/- mice, 20 ± 4%; WT mice, 45 ± 3%; P < 0.05) and diminished deposition of C3 activation products in the myocardial tissue (fB-/- mice, 0 ± 0%; WT mice, 31 ± 6%; P<0.05). Reconstitution of fB-/- mice with WT serum followed by cardiac I/R restored the myocardial necrosis and activated C3 deposition in the myocardium. In translational human studies we measured levels of activated fB (Bb) in intracoronary blood samples obtained during cardio-pulmonary bypass surgery before and after aortic cross clamping (AXCL), during which global heart ischemia was induced. Intracoronary Bb increased immediately after AXCL, and the levels were directly correlated with peripheral blood levels of cardiac troponin I, an established biomarker of myocardial necrosis (Spearman coefficient = 0.465, P < 0.01). Taken together, our results support the conclusion that circulating fB is a crucial pathophysiological amplifier of I/R-induced, complement-dependent myocardial necrosis and identify fB as a potential therapeutic target for prevention of human myocardial I/R injury.

Management of the Drug Abusing Patient in the ICU

Rapid detection of hemostatic defects presents a challenge for the anesthesiologist who must balance anesthetic and surgical considerations for maintaining adequate platelet and coagulant factors, while keeping allogenic blood exposure to a minimum. The Clot Signature Analyzer®, a point-of-care device capable of rapid response and easy interpretation is described here. Its applicability in two obstetrical patients with platelet dysfunction is discusssed.

Severe heart failure and mechanical circulatory support.

Substance use is often associated with motor vehicle accidents, falls, drownings, thermal injuries, homicide, and suicide. In the United States half of the trauma beds are occupied by patients involved in alcohol-related traffic accidents. Cocaine and cannabis use place the patient at a higher risk of all types of injuries. Patients who stay in the ICU may develop withdrawal syndromes; these are physiologic responses to abrupt withdrawal or reduction of drug use and complicate the management of these patients.

The relationship between the photoplethysmographic waveform and systemic vascular resistance

Cardiogenic shock (CS) is a life-threatening emergency that occurs frequently with acute coronary syndromes (ACSs) and is associated with high mortality. Cardiac failure with CS continues to be a frustrating clinical problem, where recent research has suggested that the peripheral circulation and neurhormonal and cytokine systems play a role in the pathogenesis and persistence of CS. The management of this condition requires a rapid and a well-organized approach. The underlying pathophysiology of CS includes cardiac failure with underperfused myocardium, hypotension, and microcirculatory hypoperfusion in the presence of adequate circulating fluid volume and left ventricular (LV) filling pressures, mostly after acute myocardial infarction (MI). Although ST-elevation MI is encountered in most patients (5% to 8%), CS may also develop in patients with non–ST-elevation MI (2.5%). In the setting of acute MI, the overall in-hospital mortality rate is approximately 60% in medically treated patients, with higher rates in those older than 75 years. Women account for approximately 40% of all cases of CS due to MI. The factors most predictive of increased mortality after CS include advanced age, presence of renal failure, cardiac output at presentation, time to reperfusion, ejection fraction <30%, multivessel coronary disease, and the presence of moderate-to-severe mitral regurgitation (MR).