Clinical review: practical recommendations on the management of perioperative heart failure in cardiac surgery.

Acute cardiovascular dysfunction occurs perioperatively in more than 20% of cardiosurgical patients, yet current acute heart failure (HF) classification is not applicable to this period. Indicators of major perioperative risk include unstable coronary syndromes, decompensated HF, significant arrhythmias and valvular disease. Clinical risk factors include history of heart disease, compensated HF, cerebrovascular disease, presence of diabetes mellitus, renal insufficiency and high-risk surgery. EuroSCORE reliably predicts perioperative cardiovascular alteration in patients aged less than 80 years. Preoperative B-type natriuretic peptide level is an additional risk stratification factor. Aggressively preserving heart function during cardiosurgery is a major goal. Volatile anaesthetics and levosimendan seem to be promising cardioprotective agents, but large trials are still needed to assess the best cardioprotective agent(s) and optimal protocol(s). The aim of monitoring is early detection and assessment of mechanisms of perioperative cardiovascular dysfunction. Ideally, volume status should be assessed by 'dynamic' measurement of haemodynamic parameters. Assess heart function first by echocardiography, then using a pulmonary artery catheter (especially in right heart dysfunction). If volaemia and heart function are in the normal range, cardiovascular dysfunction is very likely related to vascular dysfunction. In treating myocardial dysfunction, consider the following options, either alone or in combination: low-to-moderate doses of dobutamine and epinephrine, milrinone or levosimendan. In vasoplegia-induced hypotension, use norepinephrine to maintain adequate perfusion pressure. Exclude hypovolaemia in patients under vasopressors, through repeated volume assessments. Optimal perioperative use of inotropes/vasopressors in cardiosurgery remains controversial, and further large multinational studies are needed. Cardiosurgical perioperative classification of cardiac impairment should be based on time of occurrence (precardiotomy, failure to wean, postcardiotomy) and haemodynamic severity of the patient's condition (crash and burn, deteriorating fast, stable but inotrope dependent). In heart dysfunction with suspected coronary hypoperfusion, an intra-aortic balloon pump is highly recommended. A ventricular assist device should be considered before end organ dysfunction becomes evident. Extra-corporeal membrane oxygenation is an elegant solution as a bridge to recovery and/or decision making. This paper offers practical recommendations for management of perioperative HF in cardiosurgery based on European experts' opinion. It also emphasizes the need for large surveys and studies to assess the optimal way to manage perioperative HF in cardiac surgery.

Computer-mediated mobile messaging as collaboration support for nurses.

Collaboration in hospitals is coordinated mainly by communication, which currently happens by face-to-face meetings, phone calls, pagers, notes and the electronic patient record. These habits raise problems e.g., delayed notifications and unnecessary interruptions. Dealing with these problems could save time and improve the care. Therefore we designed and prototyped a mobile messaging solution based on two specific scenarios coming from observations at a cardiology department of a Norwegian hospital. The main focus was on supporting the work of nurses. One prototype supported patient management while another one dealt with messages related to medication planning. The evaluation of the prototypes suggested that messaging-based collaboration support is worth to explore and also gave ideas for improvement.

Diastolic arterial blood pressure: a reliable early predictor of survival in human septic shock.

BACKGROUND: Emphasis in therapy of human septic shock is shifting towards reliable end points and predictors of survival. Rationale is to study whether the evolution of cardiovascular reactivity in view of the administered doses of norepinephrine is an early predictor of in-hospital survival and to determine the optimal threshold of norepinephrine therapy and its consequences on renal function. METHODS: Observational study of a prospective cohort of patients in septic shock, hospitalized in intensive care unit at least 24 hours before requiring norepinephrine. Excluded were patients requiring <72 hours of continuous norepinephrine (16 patients) or who received corticosteroids. Hemodynamic parameters (heart rate, blood pressure, urinary output, and temperature) were continuously monitored. RESULTS: Of 68 patients, 45 survived [intensive care unit stay of 24 (12-36) days, hospital stay of 36 (27-66) days], and 23 died 5 (3-10) days after septic shock onset and norepinephrine treatment. Multivariate analysis revealed four independent positive predictive factors of short-term (10 days) outcome: Simplified Acute Physiology Score (SAPS) II <50 [odds ratio (OR) 6.4, 95% confidence interval (95% CI) 1.3-30.7, p < 0.011], and on day 3 Logistic Organ Dysfunction System (LODS) score <6 (OR 29.1, 95% CI 2.7-314.3, p = 0.0056), norepinephrine concentration <0.5 mug/kg/min (OR 17.6, 95% CI 2.2-142.0, p < 0.0007), diastolic arterial pressure >50 mm Hg (OR 24.8, 95% CI 2.9-215.9, p < 0.004), but not systolic arterial pressure. CONCLUSIONS: Septic shock survival increases when dose of 0.5 mug/kg/min of norepinephrine continuously improves vascular tone within the first 48 hours, or when diastolic arterial pressure (>50 mm Hg) is restored. Norepinephrine has beneficial effects on renal function. Predictive value of LODS score on day 3 is demonstrated, while SAPS II is confirmed as the only reliable predictive factor in first 24 hours.

High incidence of myocardial ischemia during postpartum hemorrhage.

BACKGROUND: Postpartum hemorrhage remains a major cause of global maternal morbidity and mortality, even in developed countries, despite the use of intensive care units. This study sought to (1) assess whether myocardial ischemia could be associated with and even aggravate hemorrhagic shock in young parturients admitted for postpartum hemorrhage, and (2) identify the independent risk factors for myocardial ischemia. METHODS: On their referral to the intensive care unit, a multidisciplinary team managed parturients with severe postpartum hemorrhage. Ventilation, transfusion, catecholamines, surgery, or angiography with uterine embolization were provided as clinically indicated. Plasma cardiac troponin I levels were used as a surrogate marker of acute myocardial injury and electrocardiograms of myocardial ischemia. RESULTS: A total of 55 parturients were referred with severe postpartum hemorrhage, all in hemorrhagic shock. Twenty-eight parturients (51%) had elevated serum levels of cardiac troponin I (9.4 microg/l [3.7-26.6 microg/l]), which were associated with electrocardiographic signs of ischemia and deteriorated myocardial contractility and correlated with the severity of hemorrhagic shock. Indeed, multivariate analysis identified low systolic and diastolic arterial blood pressure (< 88 and < 50 mmHg, respectively) and increased heart rate (> 115 beats/min) as independent predictors of myocardial injury. In addition, all patients who were given catecholamines also had elevated cardiac troponin I levels. CONCLUSIONS: These results suggest that treatment of postpartum hemorrhage-induced hemorrhagic shock should be coupled with concomitant prevention of myocardial ischemia, even in young parturients.

Acute right ventricular failure--from pathophysiology to new treatments.

The right ventricle (RV) provides sustained low-pressure perfusion of the pulmonary vasculature, but is sensitive to changes in loading conditions and intrinsic contractility. Factors that affect right ventricular preload, afterload or left ventricular function can adversely influence the functioning of the RV, causing ischaemia and right ventricular failure (RVF). As RVF progresses, a pronounced tricuspid regurgitation further decreases cardiac output and worsens organ congestion. This can degenerate into an irreversible vicious cycle. The effective diagnosis of RVF is optimally performed by a combination of techniques including echocardiography and catheterisation, which can also be used to monitor treatment efficacy. Treatment of RVF focuses on alleviating congestion, improving right ventricular contractility and right coronary artery perfusion and reducing right ventricular afterload. As part of the treatment, inhaled nitric oxide or prostacyclin effectively reduces afterload by vasodilating the pulmonary vasculature. Traditional positive inotropic drugs enhance contractility by increasing the intracellular calcium concentration and oxygen consumption of cardiac myocytes, while vasopressors such as norepinephrine increase arterial blood pressure, which improves cardiac perfusion but increases afterload. A new treatment, the calcium sensitiser, levosimendan, increases cardiac contractility without increasing myocardial oxygen demand, while preserving myocardial relaxation. Furthermore, it increases coronary perfusion and decreases afterload. Conversely, traditional treatments of circulatory failure, such as mechanical ventilation and volume loading, could be harmful in the case of RVF. This review outlines the pathophysiology, diagnosis and treatment of RVF, illustrated with clinical case studies.