Invasive Therapeutic Interventions Research Articles

Heart diseases affecting the liver and liver diseases affecting the heart

Background The association of cardiac and liver disorders has not been extensively outlined in the literature. Methods A survey of the MEDLINE database was performed to assess the current status of research regarding the association between cardiac and liver disorders. Results Combined cardiac and hepatic disorders occur in 3 different settings: heart diseases affecting the liver, liver diseases affecting the heart, and cardiac and hepatic disorders with joint etiology. The spectrum of heart diseases affecting the liver includes mild alterations of liver function tests in heart failure, cardiogenic ischemic hepatitis, congestive liver fibrosis, and cardiac cirrhosis. The liver diseases affecting the heart include complications of cirrhosis such as hepatopulmonary syndrome, portopulmonary hypertension, pericardial effusion, and cirrhotic cardiomyopathy as well as noncirrhotic cardiac disorders such as high-output failure caused by intrahepatic arteriovenous fistulae. Cardiac and hepatic disorders with joint etiology include infectious, metabolic, immune, vasculitic, and toxic disorders. We propose a practical approach to a diagnostic workup of combined cardiac and hepatic disorders based on recognizing the sequence of appearance of the cardiac and liver disease, presence of features of a multisystem disease, and presence of pathognomonic features. The evaluation of combined cardiac and hepatic disorders takes into consideration the expected benefit of treatment and the risks related to invasive procedures. Accordingly, investigations can be limited to ancillary tests for patients with congested liver and mild alterations of liver function tests, in cardiogenic ischemic hepatitis, patients with cardiac cirrhosis who are proposed for conservative treatment, and multisystem disease involving the heart and the liver. Conversely, comprehensive investigations are recommended when invasive therapeutic interventions are considered for the treatment of hepatopulmonary syndrome, portopulmonary hypertension, or arteriovenous fistulae. Conclusion: Classification of a patient to any of the 3 categories—heart diseases affecting the liver, liver diseases affecting the heart, and cardiac and hepatic disorders with joint etiology—permits the physician to narrow the span of the possible diagnoses and allows for a more simple workup. (Am Heart J 2000;140:111-20.)

Magnetic resonance image-guided biopsy and aspiration.

Recent advances in magnet design and magnetic resonance (MR) system technology coupled with the development of fast gradient-echo pulse sequences have contributed to the increasing interest in interventional magnetic resonance imaging (MRI). Minimally invasive diagnostic and therapeutic image-based intervention can now be performed under near real-time MR guidance, taking advantage of the high tissue contrast, spatial resolution, vascular conspicuity and multiplanar capabilities of MRI to achieve safe and precise needle placement. This is particularly advantageous for needle navigation in regions of complex anatomy, such as the suprahyoid neck. This article discusses the theoretical concepts and clinical applications of MR for guidance for biopsy and aspiration, and highlights the technical developments that provide the foundation for interventional MRI.

Clinical negligence and nurses.

The number of nurse specialists and nurse practitioners is increasing and all nurses are delivering more invasive medical and therapeutic interventions. As independent professionals acting on their own initiative, it is inevitable that specialist nurses will become more involved in clinical negligence actions. These actions will deal with alleged negligence in the context of obtaining consent and acts and omissions in practice.

Difference in countries' use of resources and clinical outcome for patients with cardiogenic shock after myocardial infarction: results from the GUSTO trial

Use of aggressive and invasive interventions is more common in the USA than in other countries. We have compared use of resources for patients with cardiogenic shock after myocardial infarction in the USA and in other countries, and assessed the association between use of resources and clinical outcomes. We analysed data for patients with cardiogenic shock after myocardial infarction who were enrolled in the GUSTO-I trial (1891 treated in the USA, 1081 treated in other countries). Patients were randomly assigned combinations of streptokinase, heparin, and accelerated tissue-plasminogen activator (t-PA), then decisions about further interventions were left to the discretion of the attending physician. The interventions included in our analysis were: pulmonary-artery catheterisation, cardiac catheterisation, intravenous inotropic agents, ventilatory support, intra-aortic balloon counterpulsation (IABP), percutaneous transluminal coronary angioplasty (PTCA), and coronary bypass graft surgery (CABG). The primary outcome measure was death from any cause at 30 days of follow-up. Patients who were treated in the USA were significantly younger than those treated elsewhere (median 68 [IQR 59-75] vs 70 [62-76], p < 0.001), a smaller proportion had anterior infarction (49 vs 53%, p < 0.001), and they had a shorter time to treatment (mean 3.1 vs 3.3 h, p < 0.001). Aggressive diagnostic and therapeutic procedures were used more commonly in the USA than in the other countries: cardiac catheterisation (58 vs 23%); IABP (35 vs 7%); right-heart catheterisation (57 vs 22%); and ventilatory support (54 vs 38%). 483 (26%) of the patients treated in the USA underwent PTCA, compared with 82 (8%) patients in other countries. Patients who underwent revascularisation had better survival in all countries. Adjusted 30-day mortality was significantly lower among patients treated in the USA than among those treated elsewhere (50 vs 66%, p < 0.001). The difference in mortality remained at 1 year-56% of patients treated in the USA died versus 70% of patients treated elsewhere (hazard ratio 0.69 [95% CI 0.63-0.75], p < 0.001). 30-day and 1-year mortality was significantly lower among patients treated in the USA than among those treated in other countries. This difference in mortality may be due to the greater use of invasive diagnostic and therapeutic interventions in the USA.

Prophylactic use of continuous renal replacement therapies in patients with normal renal function

Conventionally, the term prophylactic dialysis refers to the early intitiation of renal replacement therapy in fully established acute renal failure (ARF). Available studies have compared the start of hemodialysis at blood urea nitrogen (BUN) levels greater than 120 to 165 mg/dL versus 50 to 100 mg/dL. Studies on true prophylactic treatment in patients at risk of developing ARF with normal or only mildy impaired renal function have not been performed. Recently introduced continuous renal replacement therapies (CRRTs) that exert multiple positive effects on various organ functions may gain importance in preventing the development of ARF and additional organ dysfunction in sepsis and multiple-organ dysfunction syndrome (MODS), the most important causes of ARF in critical care medicine. Considering the prophylactic use of CRRT, one has to weigh potential advantages with potential side effects and complications of this invasive therapeutic intervention. Among the advantages of CRRT are the correction and maintenance of fluid homeostasis, the regulation of intrathoracic fluid volume, improvement of cardiovascular stability, the facilitation of infusion and/or nutritional therapy and/or drug dosing, and relief of renal work load. At present, there is no evidence that a quantitative relevant elimination of putative mediators involved in the development and/or maintenance of sepsis and/or MODS is achieved by CRRT. Potential disadvantages of CRRT include heat loss, impairment of oxygen delivery, unphysiologic load of lactate, loss of nutritional substrates and good molecules, need of continuous anticoagulation, and potentially, the induction of a chronic inflammatory reaction by prolonged blood-membrane interaction. Moreover, any renal replacement therapy obviously impairs residual renal function. Certainly, this is more pronounced with intermittent modalities, but CRRT also reduces renal function by at least 10%. With present evidence, there is no justification to initiate CRRT in a patient with completely normal renal function. However, in any patient with sepsis and/or at risk for developing MODS, with deranged fluid balance, impaired water excretion, and cardiovascular instability, the early institution of CRRT is advisable even when overall renal function is not grossly impaired.

Experimental assessment of newly devised transcatheter stent-graft for aortic dissection

Despite recent advances, surgical results for Stanford type B dissection are not yet satisfactory because the procedure is so highly invasive. The aim of this study was to devise a new intraaortic (IA) graft that would offer less invasive treatment for type B dissection. To close the entry of type B dissections using transcatheter placement, we devised an IA graft (inner diameter, 15-20 mm; length, 40 to 60 mm) in which a self-expandable stent was covered with a thin, open-cell-structured polyurethane jacket. In acute animal experiments in which type B aortic dissections were prepared in 4 mongrel dogs, IA grafts were implanted to close the entry using a transfemoral catheter sheath, and closure of all the entries was confirmed by aortography. In chronic experiments, five IA grafts for normal descending aortas and one IA graft for an experimentally dissected aorta were implanted to observe histologic biocompatibility for up to 8 months. Histopathologic examination conducted at the projected sacrifice periods revealed that endothelialization of the luminal surface of the IA graft had begun as early as 1 month after implantation and was completed within 4 months. The prototype device that we developed may be promising as an effective, minimally invasive therapeutic intervention for closure of the entry site of type B dissection.

Coronary Arteriography Should Not Be Routinely Used Postinfarction in Patients Having Received Thrombolytic Therapy.

The use of thrombolytic agents in the context of an acute myocardial infarction has resulted in a significant decrease in postinfarction mortality. However, at this time, little information supporting the routine use of invasive diagnostic and therapeutic interventions in all patients with acute myocardial infarction having received thrombolytic agents is available. Rather, the available data support a conservative strategy, which recommends the judicious use of these techniques in patients with evidence of clinical ongoing ischemia or in patients with a positive predischarge exercise stress test. Several potential explanations have been identified, the most important being the instability of the plaque in the early postinfarction period and the importance of functional capacity as an independent risk factor for subsequent morbidity and mortality. Until studies showing that routine coronary arteriography improves the prognosis of patients with negative predischarge exercise tests, we believe that it will be difficult to justify routine coronary arteriography even in patients with left ventricular dysfunction postinfarction. This more conservative approach should result in significant savings and a more rational use of available resources.

Airway Management and Sedation for Pediatric Transport

Appropriate airway management is essential for the successful transport of sick children. Airway management begins with a thorough history and physical examination and may proceed to invasive therapeutic interventions. Successful care of the pediatric airway can be achieved only with a thorough knowledge of airway management technique and equipment. In addition, familiarity and understanding of the pharmacologic adjuvants to airway management and sedation will help to achieve the primary objective of any transport team, namely a safe and smooth transport of the critically ill child.

When is enough enough? Ethical dilemmas on the burn unit.

Modern burn care often leads to the dilemma of what should or should not be done for patients with clinical deterioration and organ system failure who fail to respond to therapy. The questions are, "When is enough enough?" and "Who decides?" We have developed a structured conference to address these issues and to help us decide whether to recommend continued invasive diagnostic and therapeutic intervention or to allow the patient to "die with dignity." This conference can be requested by any member of the burn team who feels uncomfortable with what is being done for and/or to a patient. It is a meeting of the entire team, and its purpose is to discern the judgment of the group. When the consensus decision is to forego additional therapy, the decision is then presented to the patient (if he or she is able to understand and respond) and to the patient's family. The decision made by the group removes the responsibility of any individual from making a stressful decision if the patient's condition deteriorates abruptly. Patients who accept this decision exhibit a peaceful calm that invariably reaffirms the group dynamics. The family often experiences a great deal of relief, because they are not forced to make the decision even though they wanted it made. Inviting nurses to be active participants in the decision process builds their personal and professional self-esteem and binds the team members into a more tightly knit community. The attending staff may perceive this process as an abdication of responsibility; however, in our experience the consensus conference has led to a conviction that the wisdom of the team is always best.

Host Defense Mechanisms and Compromises in the Trauma Patient

Infection in multiple trauma patients remains the number one complication and the second leading cause of death in this population. Because each type of injury has its own intrinsic infection risks and the treatment of the injury necessitates the use of invasive therapy, the prevention of infection may not be possible. The most effective infection control measures may be continual nursing assessment of the patient, including observing for subtle changes that would indicate the presence of an infection. It is the early distinction of infection as the underlying mechanism of inflammatory responses and fever that best facilitates an expedient and appropriate course of therapy. Classic recommendations of infection control practices such as hand washing and meticulous aseptic technique during all procedures, plus an awareness of the many ways that microorganisms can contaminate and innoculate the patient are the best strategies for nursing care. Nursing actions must be guided by a clear understanding of the patient's host defense mechanisms and how they are jeopardized by both the injury and the therapy. This understanding facilitates the implementation of specific nursing care measures to promote the restoration of normal host defense mechanisms and to prevent further compromise of the trauma patient while in the ICU.

Prognostic significance of postinfarction arrhythmias and biventricular dysfunction under stress.

The prognostic relevance on mortality of right ventricular dysfunction in comparison with left ventricular function during stress, complex arrhythmias detected by Holter monitoring, and variables of exercise performance, was evaluated via a retrospective follow-up of more than four years for cardiac mortality of all patients in the chronic stage after myocardial infarction who were referred serially during a one-year period to stress radionuclide-ventriculography and 24-h Holter monitoring. A sample of 47% (213) of all patients admitted after myocardial infarction to the rehabilitation center during 1983 was investigated by scintigraphic stress testing and Holter monitoring and were followed up. Subsequent medication and invasive therapeutic interventions were documented. The mortality during a mean follow-up period of 3.9 years in 213 patients (mean age, 56 years) was 14.6%. Significantly decreased values of left and right ventricular ejection fractions during stress scintigraphy (38 +/- 14 versus 50 +/- 15%, p = 0.000 and 45 +/- 13 versus 54 +/- 11%, p = 0.001, respectively) were revealed in the cardiac deceased patient cohort compared with the remainder. Complex arrhythmias during Holter monitoring occurred twice as often (62 vs. 34%, p = 0.0059) in later deceased patients. Lifetable analysis demonstrated that patients with biventricular stress dysfunction had a significantly worse survival prognosis than those with monoventricular dysfunction. Multivariate nonlinear Cox survival analysis revealed that left and right ventricular ejection fraction during stress and arrhythmias were of independent prognostic significance compared with multiple clinical variables including those of exercise performance. Thus, apart from left ventricular dysfunction and arrhythmias, scintigraphically assessed right ventricular stress dysfunction is a further marker of poor prognosis after myocardial infarction. This reflects the previously neglected pathophysiologic significance of right ventricular performance in patients after myocardial infarction.

Making the coronary care unit cost-effective

Coronary care units (CCUs) have now been in use for 20 years, and it is generally acknowledged that they have helped to reduce hospital mortality for patients with acute myocardial infarction. In recent years the indications for admission to a CCU have been greatly expanded to include all patients with suspected myocardial infarction and a variety of other manifestations of cardiovascular disease including primary arrhythmias and heart failure. The focus of the CCU has also broadened to include the prevention of major complications and the use of a variety of invasive and noninvasive diagnostic and therapeutic interventions before, as well as in response to, complications. With the changing indications for CCU admissions and the changing use of the CCU, new problems have arisen. The number of patients who might benefit from CCU care is now much larger and may at any given time greatly exceed the number of beds available. Decisions regarding who should be admitted to the CCU, how long a patient should stay in the CCU and which of the large and growing armamentarium of diagnostic and therapeutic interventions should be used are now increasingly important. These decisions have not only medical but also economic implications. Based on a 5-year experience with an intensive care unit computer data bank, strategies for more cost-effective CCU use have been explored. This has involved identification of high- and low-risk subsets of patients and modifications of standard operating procedures. The common clinical problems of chest pain, arrhythmias, syncope, pulmonary edema and myocardial infarction will be used as examples.