El papel del catéter de Swan-Ganz en la actualidad

Ultrasound use after cardiac surgery

Surgical complexity as well as comorbidities in patients undergoing cardiac surgery is increasing. Early detection and management of post-surgical complications are key points to reduce morbidity and mortality. Ultrasound technique plays a main rol in cardiopulmonary, hemodynamic and etiological assessment of the critically ill, providing immediate, reliable and, sometimes, conclusive information, clarifying many clinical situations with an inappropiate therapeutic response. For all these reasons ultrasound is an essential diagnostic tool. In this chapter we will focus, mainly, on functional and hemodynamic assessment and on the detection of most common cardiological complications in the postoperative period after cardiac surgery.

Perforation of the left ventricle wall due to the insertion of a pulmonary artery catheter. A case report

Despite the widespread and frequent use in our setting of pulmonary artery catheters for haemodynamic management in critically ill patients, particularly after heart surgery, some experts continue to question the need for these devices. Clinicians need to weigh up the risks and benefits of pulmonary artery catheters placement and bear in mind the potential complications which, though rare, can be potentially fatal. We present a pulmonary artery catheters-related complication not hitherto described in the literature, involving perforation of the interventricular septum and left ventricular free wall caused by a kink in the pulmonary artery catheters that was not suspected, and only diagnosed by direct vision of the heart after pericardial opening. In the interest of patient safety, we must consider the impact of adverse events; improving our situational awareness and our understanding of the mechanisms behind such events can help reduce the likelihood of repetitions in the future.

Impact of positive end-expiratory pressure on cardiac index measured by ultrasound cardiac output monitor*

OBJECTIVES

To evaluate the impact of different levels of positive end-expiratory pressure on cardiac index in children receiving mechanical ventilation. To explore the effect of lung recruitment on the relationship between positive end-expiratory pressure and cardiac output.

DESIGN

Prospective, single center, and interventional.

SETTING

PICU in a tertiary care children's hospital.

PATIENTS

Fifty mechanically ventilated, hemodynamically stable children between 1 month and 20 years old.

INTERVENTIONS

Positive end-expiratory pressure was altered to levels of 0, 4, 8, and 12 cm H2O in random order. Cardiac output was measured at different levels of positive end-expiratory pressure by continuous wave Doppler ultrasound (ultrasound cardiac output monitor). Baseline vital signs were recorded, as well as cardiac index and dynamic compliance of the respiratory system at each positive end-expiratory pressure level.

MEASUREMENTS AND MAIN RESULTS

Median cardiac index decreased marginally as positive end-expiratory pressure increased, with a median change in cardiac index of 0.4 (< 10%) between positive end-expiratory pressure of 0 and 12 cm H2O (p < 0.001). There was no difference in heart rate or blood pressure as positive end-expiratory pressure increased (p > 0.5). For a subset of 29 patients (58%) in whom the highest dynamic compliance was at a positive end-expiratory pressure of 4 or 8 cm H2O, there was no difference in cardiac index between positive end-expiratory pressure 4 below versus positive end-expiratory pressure at highest dynamic compliance, or cardiac index between positive end-expiratory pressure 4 above versus positive end-expiratory pressure at highest dynamic compliance (p > 0.2). Regardless of optimal dynamic compliance, cardiac index decreased as positive end-expiratory pressure increased (p = 0.02).

CONCLUSIONS

In hemodynamically stable mechanically ventilated children, although there is a statistically significant decrease in cardiac output as positive end-expiratory pressure is increased between 0 and 12 cm H2O, the mean change is less than 10%, and this is likely not clinically significant. In the presence of lung disease, intensive care physicians should feel less reluctant in their use of positive end-expiratory pressure for hemodynamically stable patients.

[Hemodynamic monitoring in the critically patient. Recomendations of the Cardiological Intensive Care and CPR Working Group of the Spanish Society of Intensive Care and Coronary Units]

Hemodynamic monitoring offers valuable information on cardiovascular performance in the critically ill, and has become a fundamental tool in the diagnostic approach and in the therapy guidance of those patients presenting with tissue hypoperfusion. From introduction of the pulmonary artery catheter to the latest less invasive technologies, hemodynamic monitoring has been surrounded by many questions regarding its usefulness and its ultimate impact on patient prognosis. The Cardiological Intensive Care and CPR Working Group (GTCIC-RCP) of the Spanish Society of Intensive Care and Coronary Units (SEMICYUC) has recently impulsed the development of an updating series in hemodynamic monitoring. Now, a final series of recommendations are presented in order to analyze essential issues in hemodynamics, with the purpose of becoming a useful tool for residents and critical care practitioners involved in the daily management of critically ill patients.

[Evaluation of contractility and postloading in the intensive care unit]

Cardiovascular failure is a common disorder in critical care medicine. When admitted to the ICU, patients with hemodynamic deterioration should be examined rapidly to correctly assess the main determinants of cardiovascular function (preload, afterload and contractility). This review examines the assessment of contractility and afterload involving the combined use of several hemodynamic monitors, which allows different approaches to the same problem, with a view to improving the efficiency of management and treatment in critically ill patients.

Evaluation of pulmonary hypertension and surgical outcome by dynamic pulmonary perfusion imaging in patients with valvular disease

PURPOSE

The gold standard for assessing the degree of pulmonary hypertension is by right ventricular catheterization, an invasive procedure. This study was carried out to evaluate a noninvasive method using dynamic pulmonary perfusion imaging (DPPI) for assessing pulmonary hypertension and surgical outcome in patients with valvular heart disease.

METHODS

A total of 116 patients (50 men, 66 women, mean age: 45.8 ± 10.7 years) with valvular disease and 10 healthy volunteers (4 men, 6 women; mean age: 40.2 ± 12.8 years) were included in this study. Baseline DPPI with Tc-99m macroaggregated albumin and right ventricular catheterization were performed in all patients, before mitral valve replacement with or without aortic valve replacement surgery, and healthy volunteers. At 7 to 14 days postsurgery, 105 patients were re-evaluated with DPPI. A total lung region of interest was used to calculate a time-activity curve from the DPPI. The lung equilibrium time (LET: time from Tc-99m macroaggregated albumin entering the lungs to equilibrium) was measured. Receiver operating characteristic analysis of LET for diagnosing pulmonary hypertension was carried out.

RESULTS

LET in patients with valvular heart disease was significantly prolonged compared with those in 10 healthy volunteers (P < 0.001). LET was 14.79 ± 4.37 seconds and 27.78 ± 10.26 seconds in 10 healthy volunteers and patients, respectively). A strong correlation between LET and mean pulmonary arterial pressure (r = 0.827, P < 0.001) was found. Using mean pulmonary arterial pressure as a gold standard and threshold value of LET at 22.7 seconds, the sensitivity and specificity of LET for assessing pulmonary hypertension were found to be 94.7% and 78.0%, respectively. The pre- and postsurgery LET were found to be significantly different (27.48 ± 9.83 seconds vs. 21.33 ± 6.18 seconds, P < 0.001).

CONCLUSION

DPPI is an accurate and noninvasive method for evaluating pulmonary hypertension and surgical outcome in patients with valvular heart disease.