Cardiopulmonary Emergencies in Older Adults





Older adults are susceptible to serious illnesses, including atrial fibrillation, congestive heart failure, pneumonia, and pulmonary embolism. Atrial fibrillation is the most common arrhythmia in this age group and can cause complications such as thromboembolic events and stroke. Congestive heart failure is the most common cause of hospital admission and readmission in the older adult population. Older adults are at higher risk for pulmonary embolism because of age-related changes and comorbidities. Pneumonia is also prevalent and is one of the leading causes of death.


Key points








  • Older adults have age-related changes that make them more susceptible to cardiopulmonary disease.



  • Older adults have higher morbidity and mortality.



  • Older adults can present with atypical symptoms.



  • Treatment should be decided through shared decision making with patients and their families.




Introduction


The number of Americans aged 65 years and older will nearly double to 95 million over the next 40 years. As patients age, they undergo physiologic changes that make them more susceptible to certain diseases. This article discusses 4 common cardiopulmonary emergency department (ED) presentations with a focus on the unique considerations of older adult patients, namely atrial fibrillation (AF), congestive heart failure (HF), pulmonary embolism (PE), and pneumonia.


Atrial fibrillation


Epidemiology and Pathophysiology


AF is the most common cardiac arrhythmia, affecting nearly 2.5 million people in the United States. Older adults are disproportionately affected by this condition, and 70% of all patients who have AF are between the ages of 65 and 85 years.


With aging, the heart undergoes structural remodeling as well as changes in neural regulation. Enlargement of the left atrium, autonomic neural dysregulation, ion channel dysfunction, and reduced left ventricular diastolic filling from hypertrophy can all increase an older adult’s risk of developing AF.


Patients with AF are at high risk for stroke, with a significantly increased risk in older adults (up to 23.5% in patients aged 80–90 years). Furthermore, older adults are more likely to have severe functional deficits from a stroke affecting their daily living and placing them at higher risk for falls.


Anticoagulation therapy is the main preventive method for thromboembolic stroke; however, increased bleeding risk, frequent falls, and medication interactions are major considerations in older patients.


Management


In the ED, treatment of AF in older patients with a rapid ventricular rate is similar to other patients. If the patient is unstable (has hypotension, altered mental status, active chest pain, shortness of breath, or signs of acute congestive HF), treatment should be targeted toward stabilizing the patient with synchronized electrical cardioversion. If the patient is clinically stable, practitioners can choose to treat AF with rate control (β-blocker or calcium channel blocker) or rhythm control (ie, chemical or electrical cardioversion) therapy, with studies showing an overall similar success rate but a decreased ED length of stay in those patients who are cardioverted. ,


Another consideration in ED patients who are presenting with AF is the duration of symptoms. In the past, studies have suggested that patients in rapid AF for less than 48 hours have a much lower risk for venous thromboembolic events (VTEs) within 30 days after electrical cardioversion (1.1%). However, more recent studies have recommended an even shorter electrical cardioversion window of less than 12 hours, with a risk for VTE of only 0.3%. In addition, the calculation of a CHA2DS2-Vasc (congestive HF; hypertension; age ≥75 years; diabetes mellitus; prior stroke, TIA, or thromboembolism; vascular disease; age 65–74 years; sex category) score is useful in determining risk of VTEs after cardioversion and in deciding on anticoagulation in patients with AF. Lip and colleagues showed zero thromboembolic events in patients with a CHA 2 DS 2 -VASc score of 0, less than 1% with a score of 1, and a rate of 1.9% to 3.9% events in patients with a score of 2 to 5.


Considerations for anticoagulation in older patients


Anticoagulation for prevention of VTEs in patients with AF has been a controversial topic, especially in older patients who have an increased risk of falls and bleeding. The 2 mainstays of anticoagulation therapy are vitamin K antagonists (VKAs; eg, warfarin), which require frequent International Normalized Ratio (INR) checks, and direct oral anticoagulants (DOACs; eg, rivaroxaban, apixaban, dabigatran). An important age-related change is impairment in renal function, which leads to decreased elimination of VKA and DOACs and thus an increased bleeding risk, as reflected in bleeding prediction scores such as HAS-BLED (hypertension, abnormal renal/liver function, stroke, bleeding history or predisposition, labile INR, elderly, drugs/alcohol concomitantly) or HEMORR 2 HAGES (hepatic or renal disease, ethanol abuse, malignancy history, older [age>75 y], reduced platelet count or function, rebleeding risk, hypertension [uncontrolled], anemia, genetic factors, excessive fall risk, stroke history, maximum score) , ( Tables 1 and 2 ).



Table 1

HAS-BLED





































Risk Factor Score
Hypertension
Uncontrolled, >160 mm Hg systolic
1
Renal disease
Dialysis, Cr>2.26 mg/dL or >200 μmol/L
1
Liver disease
Cirrhosis or bilirubin >2× normal or with ALT/AST/AP>3× normal
1
Stroke history 1
Prior major bleeding 1
Labile INR
Unstable/high INR; time in therapeutic range <60%
1
Age>65 y 1
Medication predisposing to bleeding
Aspirin, clopidogrel, NSAIDs
1
Alcohol use
≥8 drinks/wk
1
Maximum score 9

A score of 0 to 2 indicates low risk of bleeding; a score of ≥3 indicates high risk of bleeding.

Abbreviations: ALT, alanine aminotransferase; AP, alkaline phosphatase; AST, aspartate transaminase; Cr, creatinine; NSAIDs, nonsteroidal antiinflammatory drugs.


Table 2

HEMORR 2 HAGES











































Clinical Characteristic Score
Hepatic or renal disease 1
Ethanol abuse 1
Malignancy history 1
Older (age >75 y) 1
Reduced platelet count or function 1
Rebleeding risk 2
Hypertension (uncontrolled) 1
Anemia 1
Genetic factors 1
Excessive fall risk 1
Stroke history 1
Maximum score 12

A score of 0 to 1 indicates low risk of bleeding; a score of 2 to 3 indicates intermediate risk; a score ≥4 indicates high risk of bleeding.


Cost of therapy is an important consideration when choosing a therapy because the DOACs are significantly more expensive than warfarin. However, transportation to laboratory draws must also be considered. In low-risk patients with a CHA 2 DS 2 -VASc score of 0 to 1, 81 mg of aspirin is an option.


Multiple clinical trials and meta-analyses have shown a relative risk reduction for aspirin versus placebo of 21%, with an even larger risk reduction of 62% seen for warfarin versus placebo . , However, older patients also have a higher risk for life-threatening or fatal bleeding, with an anticoagulation-intensity adjusted relative risk of 4.6 in patients older than 80 years.


Clinicians should use caution in prescribing anticoagulation therapy in patients who are at high risk for falls and should have a risk-versus-benefit discussion with all patients. Recent studies on fall-related hemorrhage events in patients on VKA are mixed, with some studies showing no difference in rates of acute intracranial hemorrhage, whereas others do show increased rates of bleeding. Patients with a higher CHA 2 DS 2 -VASc score of 2 or greater, indicating an increased risk for stroke and myocardial infarction (MI), seem to benefit overall from anticoagulation, even in the setting of an increased risk of hemorrhage.


A meta-analysis by Deng and colleagues included 5 phase III randomized control trials to evaluate the efficacy and safety of VKA versus DOACs in the prophylaxis of stroke or systemic embolism in older patients (>75 years old). They found that DOACs resulted in a lower incidence of stroke/systemic embolism and major bleeding compared with warfarin (hazard ratio, 0.71; 95% confidence interval, 0.33–1.50), with apixaban ranking the best (rank probabilities, 71.4%).


Summary


AF is a common condition in older patients and treatment varies depending on the duration of symptoms and clinical presentation. Acute treatment options include electrical cardioversion or medical treatment with rate versus rhythm control. An important factor to consider in patients newly diagnosed in the ED is anticoagulation for prevention of VTEs and stroke. Because older adults are often at high risk for falls or severe bleeding events, physicians should have a risk-versus-benefit discussion with their patients and should use clinical tools to assist in their decisions. Treatment options include VKAs (warfarin) or DOACs. DOACs may have a safer bleeding risk profile. Overall, treatment should be tailored to each patient using shared decision making.


Congestive heart failure


Pathophysiology and Clinical Presentation


Congestive HF is the most common cause of hospital admissions and readmissions in older adults. With increasing survival rates from MI and a growing geriatric population, acute HF is prevalent and requires prompt recognition and treatment. Survival rates for decompensated HF have not improved in recent decades despite advances in diagnosis and treatment.


Aging causes decreased elasticity of blood vessels, leading to increased afterload, left ventricular hypertrophy (LVH), and increased coronary oxygen consumption. Ischemia and fibrosis can occur when oxygen requirements are not met, causing systolic and diastolic HF. Concurrently, decreased cardiac output leads to decreased renal perfusion, which in turn activates the renin-angiotensin pathway. This increase in circulating catecholamine levels causes potent vasoconstriction and increased renal absorption that can exacerbate HF.


HF can be broadly categorized into 2 types: (1) diastolic HF, also known as HF with preserved ejection fraction; and (2) systolic HF, also known as HF with reduced ejection fraction. HFpEF accounts for approximately 50% of all patients with HF and is the most common type of HF in older adults.


The classic symptoms of HF are shortness of breath, abdominal distension, leg swelling, orthopnea, and dyspnea on exertion. Older patients often present with atypical symptoms, such as decreased appetite, confusion, and fatigue. Infection is the most common instigating cause of decompensated HF, along with medication and dietary noncompliance, cardiac arrhythmias, and anemia.


Aortic stenosis is another important consideration in older adults, with a prevalence of 2% to 7% in patients aged 65 years and older having severe aortic stenosis. In this age group, it is typically caused by diffuse atherosclerotic disease and the presentation is late because symptoms such as dyspnea, angina, and syncope can be attributed to other comorbidities. Care should be taken with vasodilators and with aggressive fluid resuscitation in those patients with a systolic murmur because this may be the only indicator. Definitive treatment in severely symptomatic patients include open surgical versus transcatheter aortic valve replacement.


Diagnosis


Acute HF is primarily a clinical diagnosis based on the patient’s history and physical examination. The patient may appear volume overloaded with abdominal distension and leg edema, or may simply have tachypnea with shortness of breath, bibasilar rales, wheezing, reduced breath sounds, and jugular venous distension.


Point-of-care ultrasonography (POCUS) is useful in evaluating for a reduced ejection fraction, a dilated and minimally collapsible inferior vena cava (>2.5 cm, <50% change in diameter), pericardial effusion, or LVH. Bedside thoracic ultrasonography can help distinguish between a volume-overloaded state and a primary pulmonary process such as obstructive lung disease. Diffuse pulmonary B lines indicate an acute interstitial process, such as pulmonary edema in the case of HF ( Fig. 1 ). Pleural effusions at the lung bases are detected with a higher sensitivity than with chest radiographs. A study by Zanobetti and colleagues , showed excellent concordance between POCUS and ED diagnosis in patients with acute HF, with a kappa of 0.81.




Fig. 1


Lung ultrasonography. ( A ) Dry lung, A lines; ( B ) wet lung, multiple B lines in a patient with decompensated HF (appearance of comet tails with ≥3 in each lung field); ( C ) large pleural effusion; ( D ) a dilated inferior vena cava.


Laboratory values


Age-adjusted pro–brain natriuretic protein (pro-BNP) for patients more than 85 years old includes a higher gray zone of 250 to 590 pg/mL and should be compared with the patient’s baseline for the most useful interpretation. High-sensitivity troponin level may be increased secondary to underlying myocardial ischemia caused by the HF state rather than acute coronary syndrome. These patients often have acute renal failure and transaminitis, which is caused by cardiorenal and cardiohepatic syndromes, respectively, from cardiac congestion and decreased blood flow to end organs.


Management


In the acute setting, rapid diagnosis and treatment are paramount to improving mortality and morbidity in older patients. Each episode of decompensation substantially worsens the long-term course of these patients. Patients should be positioned upright to improve their respiration. Oxygen therapy should only be used in patients who are hypoxic (oxygen saturation <90%). If the patient is in acute respiratory distress with pulmonary edema, noninvasive positive pressure ventilation (NIPPV) should be initiated if possible. NIPPV consistently decreases intubation rates and improves early outcomes of patients with acute cardiogenic pulmonary edema.


Initiation of a vasodilator such as nitroglycerin is first-line treatment of decompensated HF and should be titrated aggressively to reduce afterload. Options include sublingual tablets or spray, or intravenous (IV) infusion. Patients who are taking a phosphodiesterase inhibitor such as sildenafil, have severe aortic stenosis, or have an acute inferior MI should not receive vasodilators.


Angiotensin-converting enzyme inhibitors reduce preload and afterload and are useful in patients with chronic HF. Their role in acute decompensation is controversial. Inotropes should not be used unless the patient is in cardiogenic shock, because they cause increased mortality. Morphine is also associated with increased mortality. Diuresis with IV loop diuretics (eg, furosemide) should be initiated in patients with fluid overload. The Diuretic Optimization Strategies Evaluation trial showed no significant difference in patient symptoms with bolus versus continuous-infusion dosing or low-dose versus high-dose diuretics. The high-dose strategy was associated with greater relief of dyspnea, fluid loss, weight loss, and fewer serious adverse events.


Palliative care in patients with advanced HF focuses on management of symptoms rather than improving survival; oxygen is used in relieving dyspnea if the patient is hypoxic and small-dose opioids assist with air hunger and breathlessness. ,


Summary


Acute HF is the leading cause of hospital admissions and readmissions in the older population. Symptoms in the older population are often atypical. Treatments include rapid reduction of blood pressure with nitroglycerin, diuresis, and supplemental oxygen if hypoxic. Patients in severe respiratory distress benefit greatly from NIPPV.


Palliative care should be considered in frail older patients presenting with multiple readmissions for HF.


Pulmonary embolism


Pathophysiology


VTE is caused by a triad of venous stasis, activation of the blood coagulation cascade, and endothelial vein damage. Older patients are at increased risk of VTE likely secondary to enhancement of coagulation activation, increased incidence of comorbid conditions, and immobilization.


Clinical Presentation


The presentation of PE can be atypical in older patients. Syncope is a common presentation, whereas pleuritic chest pain and shortness of breath are less common. Some patients may be completely asymptomatic, leading to a delayed diagnosis.


Fewer older adults present with tachycardia and tachypnea. Furthermore, leg pain and swelling are less common. Other clinical findings, such as hypoxia, right heart strain on electrocardiogram, and chest radiograph findings, are neither sensitive nor specific for the diagnosis of PE.


Diagnostic Testing


The Wells score for VTE is valid in older patients and stratifies clinical probability for thrombus as low, intermediate, or high. The use of D-dimer testing is highly sensitive for clot rule out in patients with a low pretest probability. In the past, a 500-mg/L cutoff was used for patients at low risk for clot. More recent studies have shown that an age-adjusted D-dimer with a higher cutoff for patients as they age (age × 10 μg/L in patients >50 years old) has higher specificity in all age categories, with the most pronounced difference in patients more than 80 years old (specificity 35.2%), without adversely affecting sensitivity.


The diagnostic gold standard for PE is a chest computed tomography (CT) angiogram. Clinicians must consider renal impairment in older patients because a normal creatinine level does not always signify normal creatinine clearance. The utility of ventilation and perfusion scan is limited because it requires normal underlying lung tissue, which may not be present in older patients.


Ultrasonography Findings


POCUS is a useful diagnostic tool in patients who are critically ill. A meta-analysis shows that transthoracic echocardiogram has a high specificity (83%) and low sensitivity (53%) in the diagnosis of PE. A summary of ultrasonography findings in PE is given in Box 1 .


Jul 11, 2021 | Posted by in EMERGENCY MEDICINE | Comments Off on Cardiopulmonary Emergencies in Older Adults

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