Pulsus paradoxus
Pulsus paradoxus, or paradoxical pulse, is an exaggerated decline in blood pressure during inspiration. Normally, systolic pressure falls less than 10 mm Hg during inspiration. In pulsus paradoxus, it falls more than 10 mm Hg. (See Comparing arterial pressure waves.) When systolic pressure falls more than 20 mm Hg, the peripheral pulses may be barely palpable or may disappear during inspiration.
Pulsus paradoxus is thought to result from an exaggerated inspirational increase in negative intrathoracic pressure. Normally, systolic pressure drops during inspiration because of blood pooling in the pulmonary system. This, in turn, reduces left ventricular filling and stroke volume and transmits negative intrathoracic pressure to the aorta. Conditions associated with large intrapleural pressure swings, such as asthma, or those that reduce left-sided heart filling, such as pericardial tamponade, produce pulsus paradoxus. (See Detecting and measuring pulsus paradoxus, page 550.)
When you check for pulsus paradoxus, remember that irregular heart rhythms and tachycardia cause variations in pulse amplitude and must be ruled out before a true pulsus paradoxus can be identified.
Emergency Actions
A pulsus paradoxus may signal cardiac tamponade — a life-threatening complication of pericardial effusion that occurs when sufficient blood or fluid accumulates to compress the heart. When you detect pulsus paradoxus, quickly take the patient’s other vital signs. Check for additional signs and symptoms of cardiac tamponade, such as dyspnea, tachypnea, diaphoresis, jugular vein distention, tachycardia, narrowed pulse pressure, and hypotension. Emergency pericardiocentesis to aspirate blood or fluid from the pericardial sac may be necessary. Then evaluate the effectiveness of pericardiocentesis by measuring the degree of pulsus paradoxus; it should decrease after aspiration.
History
If the patient doesn’t have cardiac tamponade, find out if he has a history of chronic cardiac or pulmonary disease. Ask about the development of associated signs and symptoms, such as a cough or chest pain.
Physical assessment
Auscultate for abnormal breath sounds. Next, complete your cardiac and pulmonary assessments.
Medical causes
Cardiac tamponade
Pulsus paradoxus commonly occurs with cardiac tamponade, but it may be difficult to detect if intrapericardial pressure rises abruptly and profound hypotension occurs. With severe tamponade, assessment also reveals these classic findings: hypotension, diminished or muffled heart sounds, and jugular vein distention. Related findings include chest pain, pericardial friction rub, narrowed pulse pressure, anxiety, restlessness, clammy skin, and hepatomegaly. Characteristic respiratory signs and symptoms include dyspnea, tachypnea, and cyanosis; the patient typically sits up and leans forward to facilitate breathing.
If cardiac tamponade develops gradually, pulsus paradoxus may be accompanied by weakness, anorexia, and weight loss. The patient may also report chest pain, but he won’t have muffled heart sounds or severe hypotension.
Chronic obstructive pulmonary disease
The wide fluctuations in intrathoracic pressure that characterize chronic obstructive pulmonary disease (COPD) produce pulsus paradoxus and possibly tachycardia. Other findings vary but may include dyspnea, tachypnea, wheezing, productive or nonproductive cough, accessory muscle use, barrel chest, and clubbing. The patient may show labored, pursed-lip breathing after exertion or even at rest. Auscultation reveals decreased breath sounds, rhonchi, and crackles. Weight loss, cyanosis, and edema may occur.
Pericarditis (chronic constrictive)
Pulsus paradoxus can occur in up to 50% of patients with chronic constrictive pericarditis. Other findings include pericardial friction rub, chest pain, exertional dyspnea, orthopnea, hepatomegaly, and ascites. The patient also exhibits peripheral edema and Kussmaul’s sign — jugular vein distention that becomes more prominent on inspiration.
Pulmonary embolism (massive)
Decreased left ventricular filling and stroke volume in massive pulmonary embolism produce pulsus paradoxus as well as syncope and severe apprehension, dyspnea, tachypnea, and pleuritic chest pain. The patient appears cyanotic, with jugular vein distention. He may succumb to circulatory collapse, with hypotension and a weak, rapid pulse. Pulmonary infarction may produce hemoptysis along with decreased breath sounds and a pleural friction rub over the affected area.
Right ventricular infarction
Right ventricular infarction may produce pulsus paradoxus and elevated jugular venous or central venous pressure. Other findings are similar to those of myocardial infarction. Signs of right-sided heart failure may occur, such as distended neck veins, hepatomegaly, and peripheral edema.
Special considerations
Prepare the patient for an echocardiogram to visualize cardiac motion and to help determine the causative disorder. Also, monitor his vital signs and frequently check the degree of paradox. An increase in the degree of paradox may indicate recurring or worsening cardiac tamponade or impending respiratory arrest in severe COPD. Vigorous respiratory treatment, such as chest physiotherapy, may avert the need for endotracheal intubation.
Pediatric pointers
Pulsus paradoxus commonly occurs in children with chronic pulmonary disease, especially during an acute asthma attack. Children with pericarditis may also develop pulsus paradoxus because of cardiac tamponade, although this disorder more commonly affects adults. A pulsus paradoxus above 20 mm Hg is a reliable indicator of cardiac tamponade in children; a change of 10 to 20 mm Hg is equivocal.
Patient counseling
Review self-care techniques with the patient with COPD, such as pursed-lip, diaphragmatic breathing; coughing and deep-breathing exercises; and proper use of home oxygen equipment. If the patient requires pericardiocentesis, explain the procedure to him and help ease his anxiety.
Pictures
Book Source Details
- Book Title: Signs & Symptoms: A 2-in-1 Reference for Nurses
- Author(s): Springhouse
- Year of Publication: 2007
- Copyright Details: Signs & Symptoms: A 2-in-1 Reference for Nurses, Copyright © 2007 Lippincott Williams & Wilkins.
Other Book Chapters Related to Orthostatic hypotension
Read excerpts from these other book chapters related to Orthostatic hypotension:
Copyright Details: Signs & Symptoms: A 2-in-1 Reference for Nurses, Copyright © 2008 Williams & Wilkins.
More About Causes of Orthostatic hypotension
» Next page: Orthostatic hypotension (Signs & Symptoms: A 2-in-1 Reference for Nurses)
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