CHAPTER 17. Preexisting Medical Conditions
Lois Schick
OBJECTIVES
At the conclusion of this chapter, the reader will be able to:
1. Identify patients with an increased perioperative risk.
2. State the specific perioperative nursing care priorities for the high-risk patient.
3. Describe techniques to reduce perioperative morbidity and mortality.
I. PREEXISTING MEDICAL CONDITIONS
A. Increases American Society of Anesthesiologists classification
B. Increases perioperative risk, morbidity, and mortality
C. May require multiple medications
1. Increased potential for drug interactions
2. Increased potential for laboratory test alterations
3. Increased potential for noncompliance
D. May jeopardize ambulatory status
II. CARDIOVASCULAR DISEASES (see Chapter 32)
A. Hypertension
1. Definition: systolic blood pressure (BP) >140 mm Hg and/or diastolic BP >90 mm Hg on three separate readings
a. Ideal BP of 120/80 mm Hg or less
b. Hypertensive crisis: BP >180/110 mm Hg or mean arterial pressure >150 mm Hg
2. Incidence: 24% of U.S. population; greater in males than females
3. Significance
a. Risk factor for coronary artery disease, cerebrovascular accidents, congestive heart failure, arterial aneurysm, and end-stage renal failure
b. Common in diabetics associated with diabetic neuropathy
4. Etiology and findings
a. Severe hypertension (diastolic BP >110 mm Hg): immediate evaluation with surgery cancelled because of increased cardiac morbidity
b. Primary (essential hypertension): untreated or inadequate treatment
(1) Accounts for >95% of patients
(2) Risk factors (Box 17-1)
BOX 17-1
PRIMARY RISK FACTORS FOR HYPERTENSION
Family history
Black race
Obesity
Hyperlipidemia
Diabetes
Tobacco use
Excessive alcohol use
Stress
Sedentary lifestyle
Aging
Oral contraceptives
High-fat diet, high-sodium diet, or both
(3) Poor compliance
(a) Lack of symptoms (silent myocardial infarction [MI])
(b) Side effects of pharmacological agents
(c) Cost of pharmacological agents
(4) Mechanisms
(a) Hyperactivity of sympathetic nervous system: epinephrine and norepinephrine increase cardiac contractility and vasoconstriction.
(b) Hyperactivity of renin-angiotensin-aldosterone system
(c) Endothelial dysfunction: vasoconstriction leads to hypertrophy of vascular smooth muscles.
c. Secondary (Box 17-2)
(1) Accounts for <5% causes
BOX 17-2
SECONDARY RISK FACTORS FOR HYPERTENSION
Increased renin-angiotensin levels
Acute and chronic glomerulonephritis
Eclampsia or preeclampsia of pregnancy
Central nervous system injuries (head, spinal cord)
Burns
Drug side effects: oral contraceptives, steroids, cocaine, amphetamines, methamphetamine, decongestants
Drug interactions: monoamine oxidase inhibitors, ethyl alcohol
Drug withdrawal: clonidine, beta-blockers, alcohol
Pheochromocytoma
Polycythemia
Coarctation of the aorta
Pituitary or adrenocortical hyperfunction: Cushing’s syndrome and primary hyperaldosteronism
Vasculitis
Scleroderma
5. Perianesthesia considerations
a. Advise patient to take routine prescription antihypertensive medication on day of surgery with sip of water.
b. Ask about presence of heart disease during preoperative interview.
c. Postoperative systemic hypertension warrants prompt assessment and treatment to minimize risks of myocardial ischemia, heart failure, stroke, and bleeding.
(1) Assess for pain.
(2) Assess for fluid overload.
B. Coronary artery disease (CAD)
1. Definition: accumulation of plaque within coronary arteries resulting in narrowing or obstruction
2. Incidence: common in men; predominantly younger than 55 years; equal in men and women older than 55
3. Significance: increased risk for MI, diabetes, hypertension, renal disease, dysrhythmias, high cholesterol, hyperlipidemia, congestive heart failure (CHF), familial incidence, and sudden death
4. Etiology
a. Atherosclerosis with obstructive deposits in coronary arteries
b. Common factors:
(1) Genetics
(2) Diet
(3) Environment
(4) Hypertension
(5) Diabetes
c. Myocardial ischemia may occur when there is an increase in oxygen demand in the following conditions:
(1) Increased sympathetic activity
(2) Surgical stress and pain
(3) Interruption of beta-blocker medications
(4) Use of sympathomimetic drugs
d. MI may occur because of reduced oxygen supply in the following conditions:
(1) Hypotension
(2) Vasospasm
(3) Anemia
(4) Hypoxia
5. Perianesthesia considerations
a. Requires evaluation and clearance from a cardiologist
b. May increase intraoperative monitoring requirements
c. Assess for any of following signs of CHF and if present, surgery may be cancelled.
(1) Shortness of breath
(2) Dyspnea on exertion or nocturnal
(3) Jugular venous distention
(4) Crackles
(5) Edema
d. Assess incidence and triggers of chest pain.
(1) If new onset (<2 months) or unstable, postpone surgery pending cardiologist evaluation.
(2) All prescription medications to be taken on morning of surgery with sip of water
e. Treatment:
(1) Coronary vasodilators (nitrates)
(2) Exercise
(3) Diet
(4) Weight loss
(5) Antihyperlipidemia drugs
(6) Aspirin
(7) Patient education
f. Second and third postoperative days are most common time for MI in noncardiac surgical patients.
g. Intraoperative ischemia designates patient as “high risk” in postoperative period.
C. Heart failure
1. Definition
a. Heart cannot pump enough blood to meet the body’s metabolic needs.
b. CHF is an interruption in circulation.
(1) Failure of heart to function normally
(2) Impairment of heart to fill or empty the left ventricle
(3) Congestion in lung and peripheral beds
(a) Respiratory symptoms
(b) Peripheral edema
2. Incidence
a. Most common inpatient diagnosis for patients older than 65 years
b. Complication of most cardiac disease: 4 to 5 million cases in United States
c. Primary diagnosis for 1 million hospitalizations
d. Medium survival after onset for men is 1.7 years and 3.2 years for women.
3. Significance: increased risk for pulmonary edema, dyspnea, peripheral edema
4. Etiology: CAD, myocardial infarction, rheumatic heart disease, volume overload, congenital heart disease, noncompliance with medications
a. Acquired acute or chronic cardiac disease
b. Congenital heart disease
c. Multiple precipitating causes
(1) Noncompliance with medications
(2) Excessive sodium
(3) Excessive intravenous (IV) fluids
(4) Drugs
(a) Beta-blockers
(b) Corticosteroids
(c) Nortriptyline
(d) Disopyramide
(e) Nonsteroidal anti-inflammatory drugs (NSAIDs)
(f) Androgens
(g) Estrogens
(h) Doxorubicin
(5) High-output states
(a) Pregnancy
(b) Fever
(c) Hyperthyroid
(d) Sepsis
(e) Arteriovenous fistula
(f) Anemia
5. Perianesthesia considerations
a. If symptomatic (see section II.B), surgery cancelled
b. Auscultate breath sounds on arrival, on admission to post anesthesia care unit phase I, and before discharge.
c. Obtain chest x-ray.
d. Obtain cardiologist clearance before surgery.
e. Increased mortality rate by 40% during first 4 years after diagnosis
f. Strict intake and output records
g. Aggressive pain management to avoid sympathetic activation of pulmonary edema intraoperatively and postoperatively
h. Regional anesthesia acceptable for peripheral operations
i. May need postoperative mechanical ventilatory support
j. Treatment:
(1) Diuretics
(2) Inotropic therapy
(3) Oxygen
(4) Low-sodium diet
(5) Ventricular assist devices
D. Mitral valve disease
1. Definition: prolapse or stenosis of mitral heart valve that results in resistance to left ventricular emptying (increased afterload)
a. Prolapse: billowing of posterior mitral leaf into the left atrium during systole
b. Regurgitation: the mitral valve does not close tightly which allows the blood to flow backward to the heart.
c. Stenosis: mechanical obstruction to left ventricular filling secondary to progressive decreases in the mitral valve orifice
2. Incidence: age <30 congenital; age >70 degenerative
3. Significance:
a. Increased risk of angina
b. Syncope
c. Fatigue
d. Dyspnea
e. Heart murmur on auscultation
f. Pulmonary embolism
g. Dysrhythmias
4. Etiology:
a. Congenital
b. Rheumatic heart disease
c. Aging
5. Perianesthesia considerations
a. It is suggested patients at greatest risk for a bad outcome from infective endocarditis take short-term preventive antibiotics before dental work.
b. Patients at greatest risk for bad outcomes include
(1) Artificial heart valves
(2) History of previous infective endocarditis
(3) Certain specific, serious congenital heart conditions
(4) Cardiac transplant that develops a problem in a heart valve
c. May be anticoagulated on warfarin; check prothrombin time/international normalized ratio (PT/INR)
(1) Patient may be asked to stop warfarin 3 days before surgery.
d. Risk of pulmonary edema
e. Avoid hypertension and acute increases in sympathetic tone.
f. Treatment
(1) Prolapse often requires no treatment.
(2) Regurgitation often requires valve replacement if ejection fraction <0.6.
(3) When symptoms increase or pulmonary hypertension develops, stenosis requires:
(a) Valve reconstruction
(b) Commissurotomy
(c) Valve replacement
(d) Prophylaxis against endocarditis
(e) Diuretics
(f) Anticoagulant therapy
(g) Low-sodium diet
(h) Controlling heart rate, because tachycardia impairs left ventricular filling and increases left atrial pressure
(i) Digoxin
(ii) Beta-blockers
(iii) Calcium channel blockers
E. Aortic valve disease (Table 17-1)
1. Insufficiency: also described as aortic regurgitation, aortic incompetence
2. Aortic stenosis
| ECG, Electrocardiogram; INR, international normalized ratio. | ||
| Insufficiency | Stenosis | |
|---|---|---|
| Definitions |
Aortic valve leaflets do not close properly
Blood flows back into left ventricle during systole
|
Stiff and fibrotic valve
Narrowing of aortic valve
|
| Incidence | Manifests in third to sixth decade | Manifests in third to sixth decade |
| Significance |
Dyspnea
Syncope
Congestive heart failure
ECG changes
Pulmonary edema
Exercise intolerance
|
Dyspnea on exertion
Chest pain (angina)
Syncope
Congestive heart failure
Exercise intolerance
Risk for bacterial endocarditis
|
| Etiology |
Rheumatic heart disease
Congenital
Marfan syndrome
Acquired disease (syphilis, aortic dissection)
Infection (endocarditis)
Trauma
|
Congenital defect
Rheumatic heart disease
Calcification
|
| Perianesthesia considerations | PREPROCEDURE
Continue preoperative medications
Monitor atrial fibrillation
Check INR
Antibiotic therapy
POST PROCEDURE Suppress catecholamines on emergence
May have delayed emergence
Monitor cardiac output
Treat atrial dysrhythmias
Restart preoperative medications (digoxin, diuretics)
Maintain or increase contractility (use dopamine)
Decrease afterload (nicardipine, nitroprusside)
Anticoagulate
|
PREPROCEDURE
Continue preoperative medications (anticoagulant therapy)
Suppress catecholamines (control pain)
POST PROCEDURE Avoid tachycardia
Avoid histamine and catecholamine release
Consider dexmedetomidine infusion (provides analgesia without respiratory depression; can delay awakening; can potentiate beta-blockers)
Restart preoperative medications
Digoxin, diuretics, anticoagulants if chronic atrial fibrillation)
|
F. Dysrhythmias
1. Definition: alteration in conduction system requiring pharmacological or surgical (automatic implantable cardiac defibrillator [AICD], pacemaker) intervention
2. Incidence: very common (dysrhythmias)
a. Use of pacemakers and AICDs increases with age.
b. Common outcome of coronary artery disease
3. Significance: increased risk of MI and progression to lethal dysrhythmias
4. Etiology:
a. CAD
b. CHF
c. Valve disease
d. Myocardial infarction
e. Hypoxia
f. Hypercarbia
g. Electrolyte imbalance
h. Acid-base alterations
i. Altered activity of the autonomic nervous system
j. Drugs (i.e., volatile anesthetics, catecholamines)
5. Perianesthesia considerations
a. Treatment: pharmacological, patient education, pacemaker (heart block, asystole), cardioversion, AICD (ventricular fibrillation)
b. Perioperative significance
(1) Patient to take anti-dysrhythmic medications on day of surgery
(2) Inquire about type of pacemaker and setting (patient may have pacer identification card); document in chart (may need to call cardiologist).
(3) Have external pacemaker readily available.
(4) Have cardiologist available, although not necessarily in the operating room (OR).
(5) If patient has AICD, bovie or cautery should not be used during surgery.
(a) If bovie or cautery must be used, AICD is turned off.
(b) External defibrillator must be available in OR suite for immediate use if needed.
III. PULMONARY DISEASES (see Chapter 31)
A. Chronic obstructive pulmonary disease (COPD)
1. Definition: term includes chronic bronchitis and emphysema.
a. Bronchitis
(1) Chronic productive cough caused by excess bronchial mucus secretions
(2) Reduction in expiratory flow rate
(3) Signs include cough, increased sputum production, dyspnea, wheezing.
b. Emphysema
(1) Characterized by abnormal permanent enlargement air spaces distal to terminal bronchioles
(2) Destruction of parenchyma
(3) Increased minute ventilation to compensate for hypercapnia
(4) Signs include barrel chest, pursed lip breathing, decreased breath sounds, dyspnea.
2. Incidence: 20% to 30% of adults younger than 40 years; greater in males than in females
3. Significance: hypoxia, hypercapnia, pneumonia, respiratory failure, bronchospasm, atelectasis
4. Etiology: cigarette smoking, air pollution, occupational exposure to smoke
5. Perianesthesia considerations
a. Treatment: bronchodilators, possibly anticholinergics and corticosteroids, patient education to stop smoking at least 8 to 10 weeks before surgery
b. General anesthesia may exacerbate symptoms and disease; regional anesthesia avoids intubation and use of controlled ventilation.
c. Patient’s respirations controlled by hypoxic drive.
(1) High flow, high concentration of oxygen may produce apnea.
(2) Nasal cannula <3 L oxygen preferred delivery system unless unable to maintain saturation
d. Encourage deep breathing and coughing after general anesthesia; postoperative pulmonary infections common
e. Ask patient to bring inhalers used to the facility on day of surgery.
f. Pulmonary function tests may be ordered preoperatively.
g. Consider impact of neuraxial blockade and/or sedation if COPD.
(1) COPD patients rely on intercostals and abdominal muscles.
(a) Clearing of secretions affected
(b) Coughing ability impacted
(c) Avoid techniques that provide sensory anesthesia above T6.
B. Asthma
1. Definition: tracheobronchial disorder characterized by obstruction to airflow secondary to narrowing of airways, edema, and inflammation
2. Incidence: 22 million cases in United States; affects 6 million children
3. Significance: increased risk of laryngospasm and bronchospasm on induction, hypoxemia, decreased peak flow rates
4. Etiology: allergic factors, genetic predisposition, smoke, infection, cold air, exercise, and occupational exposures such as grain dust, plastics, and fumes
5. Perianesthesia considerations
a. Treatment: oxygen, bronchodilators (beta-2 agonists), corticosteroids (acute asthma), mast cell stabilizers, education, mechanical ventilation
b. Encourage patient to avoid known irritants to minimize wheezing.
c. Question patient on the frequency, severity, and management of attacks.
d. Auscultate breath sounds preoperatively and postoperatively.
e. Increased risk of bronchospasm on intubation and emergence
f. Halothane, sevoflurane, and ketamine may be used because they cause bronchodilation during administration.
g. Ask patient to use and to bring any inhalers used to the facility on day of surgery.
h. If receiving steroids, determine last use and dose; may need steroid preoperatively.
(1) Steroids by inhalation diminish systemic affects.
(2) If steroid-resistant asthma, IV immunoglobin may be administered.
(3) If patient with severe asthma receiving long-term oral corticosteroid therapy, a burst of corticosteroids may need to be administered to prevent adrenal insufficiency.
i. Cancel surgery if patient has an upper respiratory infection.
C. Smoking
1. Definition: use of inhaled tobacco
2. Incidence: extremely common; teenagers, adults, and elderly. Young females fastest growing group
3. Significance: increased risk of COPD, heart disease, hypertension, peripheral vascular disease, hypoxia, poor tissue healing, postoperative pulmonary complications six times greater than that of nonsmoker, hyper-reactive airway, higher rate of prolonged mechanical ventilation
4. Etiology: access to and use of product, habituation
5. Perianesthesia considerations
a. Treatment: cessation, nicotine patch, Smokers Anonymous, self-withdrawal
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