Introduction
Patients with chest pain are the leading cause of
malpractice losses to emergency physicians and internists. Failure to diagnose myocardial
infarction (MI) accounts for 10 percent of the cases filed against emergency physicians.
Judgments and settlements in these cases total 25 percent of the dollars paid out to
claimants.
In a recent study, all discharged chest pain patients came
back for further testing the next day. Five percent of MI patients had been sent home.
What factors lead to inappropriate discharge? Physician inexperience (less than 3 years
practice) and atypical presentation.
Myocardial infarction may become an even bigger cause of
litigation in the future. Because thrombolytics can lower mortality and improve cardiac
function, suits will be filed by patients who have lost the opportunity to receive this
therapy. Back to Index.
Initial Stabilization
Patients presenting to the emergency department with chest
pain should be triaged immediately to the treatment area. Evaluation and stabilization
should begin at once.
The patient with acute chest pain should be approached in
much the same manner as the multiple-trauma patient: Stabilize the patient and treat
life-threatening conditions while obtaining the historical and physical exam information.
Any patient who presents in obvious distress, has abnormal
vital signs, or who volunteers a history of cardiac-compatible chest pain, should be
immediately stabilized with oxygen, cardiac monitor, and IV. In most emergency
departments, several care-givers will stabilize the patient, simultaneously placing nasal
oxygen, cardiac monitor, and IV, and obtaining vital signs.
If only one person is available to care for the patient,
place oxygen first, to obtain its rapid therapeutic benefits. Most protocols use 4 liters
by nasal cannula. Next attach the cardiac monitor (at this point, the most likely urgent
need is cardioversion of an evolving arrhythmia such as V-tach). Now start the IV at a
keep-open rate. The choice of D5W or normal saline is hotly debated, and probably makes no
practical difference. Once the IV is running, take vital signs.
Just as with trauma care, act to correct a life-threatening
abnormality found during initial stabilization before progressing on with the work-up. For
example, if V-tach is seen when placing the cardiac monitor, the physician takes action:
he checks skin color, skin temperature, and radial pulse; he decides the patient is
unstable, and orders an unsynchronized counter-shock. No vital signs; no 12-lead ECG
— when the clinical threshold for action is reached, the physician should act.
As a second example, suppose initial vital signs show
significant hypotension. The physician immediately obtains the specific information he
needs to act: he quickly looks at the neck veins, listens for rales, and checks the heart
tones. Then he intervenes. For example, he might order a saline fluid challenge.
Acting on information as it is received continues during
the “history and physical” portion of the evaluation. Once the physician knows
the pain is cardiac-compatible, he should not wait until after the Babinski reflexes are
tested to give nitroglycerin. Nitroglycerin should be ordered as soon as the indications
for (and lack of contraindications to) its use are established. Similarly, morphine is
given when it’s determined that the nitroglycerin has been ineffective. These
interventions should be considered part of the stabilization process. Back to
Index.
Obtaining the Chest Pain History
Most of the important decisions the physician must make
will be based on the history of the chest pain. When physical findings and lab tests are
non-specific, as they often are in chest pain patients, the history alone will decide
whether the patient is admitted to the hospital.
The history looks for clues to life-threatening causes of
chest pain: myocardial infarction, unstable angina, pulmonary embolism, pneumothorax,
mediastinitis (esophageal rupture), and aortic dissection. “Pertinent negatives”
(absence of symptoms that would make any of these diagnoses more likely) are an important
part of the historical documentation.
Obtain an accurate description of the pain’s onset,
duration, severity, nature, location, aggravating or alleviating factors, and prior
episodes. Specifically note the presence or absence of radiation of pain and any
associated symptoms (nausea, shortness of breath, sweats) and their severity.
Have the patient describe how the pain started. The pain of
angina or myocardial infarction builds up, while aortic dissection and pulmonary embolism
tend to cause “instant severe pain.” What was the patient doing? Angina at rest
has a very different prognosis from angina while running up the stairs. Pain starting as
the patient swallows a bolus of food suggests esophageal pain.
The duration of the pain also helps establish the cause.
Pain that lasts only a second or two, or pain that is constant for many days, is almost
never cardiac pain. Angina typically lasts five to 15 minutes — pain for less than a
minute is unlikely to be angina.
The nature of the pain can suggest the diagnosis. If the
patient doesn’t volunteer a description, ask him what the pain reminds him of:
burning, squeezing, pressure, tearing, stabbing. A description as poking, pinching, or
stabbing usually means chest wall pain. Hyperventilation often causes poking pains that
are migratory and unrelated to motion. Victims of aortic dissection will often describe a
well-localized “tearing” type pain. However, when the patient has pain from the
internal organs (heart, esophagus, gallbladder), the nature of the pain is unhelpful at
best, and is often misleading: a victim of myocardial infarction may complain of
“heartburn,” while the patient with esophagitis may complain of a squeezing
sensation.
Ask about the location of the pain. Pain from the internal
organs of the chest tends to be felt over a wide area. But try to make the patient commit
to a location and size of the area of pain. If the pain is small in area, located over the
chest wall, and corresponds to an area of tenderness, it’s probably chest wall pain.
Work-up of the patient who has several small and migratory locations of pain “like
tiny pins” usually will reveal no organic disease.
Question the patient about radiation of the pain. Chest
pain from reflux esophagitis, ulcer, or gallbladder will usually have an epigastric
component, but rarely radiates to the arms. Aortic dissection usually hurts in the back.
And of course, pain radiating to the jaw, shoulders, or arms suggests (but is not
diagnostic of) cardiac pain.
Ask what things affect the pain. Ask specifically whether
breathing makes it worse. Three-fourths of pulmonary embolism victims will have pleuritic
pain. Worsening with position or with motion of the arms is expected with chest wall pain,
but can occur with any cause of pleuritic pain, such as pericarditis or pleurisy. If
resting stops the pain, ask how long it takes to go away. Angina will usually take a
minute to ease, while other activity-related pains often stop instantly with rest.
Prior episodes of identical pain are helpful. A history of
multiple episodes of the same pain, lasting hours each time, virtually excludes myocardial
infarction. Ask about any constant factors for these past episodes, such as: relation to
meals or time of day, duration of pain, and factors affecting the pain. Be sure to ask if
there has been any previous work-up.
When the history seems confusing, you may be dealing with
more than one cause of chest pain. A patient with angina on exertion also may have
musculoskeletal chest pain with activity, and may have “lumped” these pains into
one. A patient with an MI after a meal may have had past episodes of heartburn or
gallbladder pain after meals. Careful questioning about the exact sensations of specific
episodes can help you avoid a mistaken diagnosis.
Ask for risk factors of cardiovascular disease or pulmonary
embolism. Your chart should list them as “pertinent negatives.”
Your decisions won’t be based on any single factor in
the history. The entire history “snapshot” is required. For example, “hurts
on my ribs when I move my arm” doesn’t automatically mean musculoskeletal chest
pain. It must be considered as part of the “42 y.o. female smoker on BCP with
fractured leg in cast who’s short of breath, hurts to breathe and hurts in ribs when
she moves her arm” picture.
Both absolute and relative contraindications to
thrombolytic therapy should be sought. Ask specifically about recent melena, active ulcer
disease, recent major surgery, stroke, or brain tumors or vascular malformations. If the
patient is diabetic, ask about retinal vascular disease. As you conclude the history, you
may already have decided that the patient will be admitted. Back to Index.
The Physical Exam in Chest Pain
As experienced physicians know, the most important part of
the physical exam of the chest pain patient is the first “lookover.” Poor skin
color, diaphoresis, tachypnea, and anxious expression alert the physician to a potentially
lethal process. The Gestault of the patient serves as a highly accurate
“severity-O-meter.”
Evaluate the meaning of the vital signs. Tachycardia is
non-specific — it can suggest shock, severe pain, or physical stress — but it
serves to alert the physician. Tachycardia is particularly likely with pulmonary embolism.
Blood pressure should be checked in both arms. A difference of over 20 mm Hg systolic
suggests aortic dissection — and will be present in about two thirds of cases.
Hypotension may suggest massive PE or cardiac shock. Fever may suggest pneumonia or
mediastinitis as the cause of chest pain. Tachypnea may simply reflect severity, or can
suggest pulmonary embolism or hyperventilation.
Your exam should seek general evidence of atherosclerosis
(or risk factors for ASVD). Note corneal lipid rings, narrowed retinal arteries, and
pigment and hair changes in the legs.
Evaluate the neck veins for distension. Check the carotids
for quality of pulse, and for bruits. The chest wall should be inspected for respiratory
motion, respiratory retractions or accessory muscle use, and precordial motion. Identify
the apical impulse (PMI). Feel for tender areas. Many older patients will have tenderness.
Only if the tender area corresponds to the location of the patient’s pain, palpation
exactly reproduces the pain, and the history suggests chest wall pain, should the
physician diagnose musculoskeletal chest pain.
Check the lungs for rales, wheezes, and asymmetrical breath
sounds. Asymmetry of breath sounds may be found in about half of patients with spontaneous
pneumothorax. However, asymmetry also can be due to splinting of the painful side of the
chest in other conditions that cause pleuritic pain. Wheezing will most likely be due to
underlying COPD, but can occur due to heart failure (cardiac asthma) or pulmonary
embolism.
Listen to the heart tones. Wide physiologic splitting of
the second heart sound (splitting wider with inspiration) can be found in right bundle
branch block or in right ventricular infarction. New paradoxical splitting is most often
due to left bundle branch block, or anterior or lateral infarction. A new fourth heart
sound (preceding the first heart tone) can occur with angina or infarction. An S3 (third
heart tone) is more likely due to underlying heart failure.
A new murmur may be significant. Aortic regurgitation
occurs in over half of patients with aortic dissection. New mitral regurgitation can occur
in patients with angina or infarction, and is due to papillary muscle dysfunction.
The extremities should be examined for pulses, edema, calf
tenderness, and signs of atherosclerotic vessel disease. Absence of pedal pulses may occur
in aortic dissection. Any swelling of the legs, especially if unilateral, raises the odds
of pulmonary embolism as the cause of chest pain. Pulmonary embolism often occurs in
patients with CHF. Back to Index.
Diagnostic Maneuvers
Trial therapy of chest pain in the emergency department can
be misleading. The placebo response may result in improvement of chest pain in about one
fourth of chest pain patients, no matter what the intervention. The spontaneous
improvement of pain may be attributed to a specific therapeutic trial, resulting in false
diagnosis.
Patients with cardiac-compatible pain should be given
sublingual nitroglycerin. About three fourths of patients with angina will have complete
pain relief within two minutes. However, most patients with esophageal spasm also will
have pain relief with nitroglycerin. Relief with nitroglycerin is not diagnostic of
cardiac pain.
A “GI Cocktail” of antacid and lidocaine can be
given for potential pain relief, but should not be relied on for diagnostic purposes. Only
25 percent of emergency patients with reflux esophagitis will have relief of pain with the
GI cocktail. More ominously, about 20 percent of MI patients will report some relief of
pain with the GI cocktail. The spontaneous resolution of an episode of unstable angina
after administering a cocktail may lull the physician into making a mistaken diagnosis
— one with potentially fatal consequences for the patient. Back to
Index.
Monitoring the Patient During Work-up
The chest pain patient should be kept on continuous cardiac
monitor. At first, a nurse should be present at the bedside. If the patient remains stable
(no change in pain pattern, no change in vital signs), the patient can later be monitored
by telemetry.
Blood pressure should be frequently monitored, preferably
by automatic bedside equipment that provides a written printout.
Pulse oximeters are often misleading (the usual problem is
false reassurance — a good oxygen saturation is reported in a patient who later turns
out to have horrible blood gases). However, they are useful because they are fast and
simple, and can monitor for a change in saturation.
The attending nurse should watch for changes in skin color,
respiratory rate or effort, sweating, or patient expression. The nurse also should report
any change in the patient’s symptoms. The physician should reevaluate the patient
immediately if any significant change occurs. Back to Index.
Laboratory Evaluation of Chest Pain
Unless the pain is obviously musculoskeletal, all patients
with chest pain should have a 12-lead ECG. To speed possible thrombolytic therapy, do the
ECG as soon as safe and practical — immediately after initial stabilization and
taking of vital signs. If the ECG machine is “busy” elsewhere, give treatment
(if needed) such as nitroglycerin, morphine, or lidocaine while awaiting the ECG.
Most patients with myocardial infarction will have an
abnormal initial ECG, although the ECG will not necessarily be diagnostic of an MI. About
one-fourth of acute MI patients will present with a completely normal ECG.
An abnormal ECG can be seen in many non-cardiac conditions.
If so, the physician has the duty to demonstrate that the ECG abnormality is either old,
unrelated to the chest pain, or caused by a non-cardiac condition. Examples of acute
conditions affecting the ECG include pulmonary embolism, electrolyte abnormalities, or
CVA. Almost 90 percent of patients with dissection will have an abnormal ECG, often
suffering acute MI due to involvement of the roots of the coronary arteries.
Obtain a chest x-ray on all patients with chest pain,
unless the pain is obviously musculoskeletal. The x-ray may show pneumothorax,
pneumomediastinum (such as from esophageal rupture), pleural effusion, or infiltrates.
Subtle findings such as loss of lung volume or unilateral decrease in vascular markings
may suggest pulmonary embolism. Dissection of the aorta can cause a wide mediastinum or
aortic knob contour changes.
If the pain is cardiac-compatible, blood tests should
include a multichannel survey with electrolytes, complete blood count, clotting studies
(PT & PTT), and baseline CPK. If the physician suspects a non-cardiac diagnosis, such
as pneumonia or pancreatitis, other tests may be helpful.
The CPK should not be used as a basis for admitting the
acute chest pain patient to the hospital. The initial CPK is often normal in acute
myocardial infarction. However, if the pain has been present for eight to 12 hours,
it’s reasonable to exclude myocardial infarction in the patient with normal CPK-MB
and normal ECG.
Draw blood gases for patients in obvious respiratory
distress, patients who may have shock or sepsis, patients in whom the diagnosis of PE can
be ruled out by normal room air blood gases, and patients with underlying lung disease who
must have monitoring of oxygen therapy. A normal arterial-alveolar diffusion gradient on
room air gases essentially excludes significant PE.
If the pain is cardiac-compatible, it’s best to await
the ECG before ordering blood gases, if the gas analysis is not critical for early
management of the patient. If the ECG shows infarction and thrombolytics are given,
bleeding may prove problematic at the arterial puncture site.
Other studies, such as perfusion scan, arteriogram, and
gallbladder ultrasound, are ordered based on clinical suspicion concerning the cause of
the chest pain. These studies should NOT be ordered routinely on a “Rule-out MI”
patient to “fish” for another diagnosis. Back to Index.
Disposition of the Chest Pain Patient
The physician must make a decision on admission or
outpatient work-up and therapy. Life-threatening causes of chest pain must be eliminated
through historical, physical, and laboratory data before the patient can be discharged to
out-patient follow-up. These critical diagnoses are unstable angina, myocardial
infarction, pulmonary embolism, pneumothorax, mediastinitis, and aortic dissection.
Of the above diagnoses, all except pneumothorax require
automatic admission. A small pneumothorax can be tapped in the emergency department, or
simply observed, with careful outpatient follow-up.
Patients with less-lethal causes of chest pain may still
require admission if the severity of the disease, underlying poor health, or patient
distress warrants it. An unfortunate side effect of recent Medicare regulations is that
the physician may have to summon greater investigative skills to find the
“criteria” for admission than was necessary to diagnose the problem.
Any patient with cardiac-compatible chest pain should be
admitted to the hospital as a “Rule-out MI,” unless the pain has been proven to
have another etiology. Although undiagnosed chest pain patients with normal initial ECG
and CPK have only a .01 percent (one-hundredth of a percent) risk of life-threatening
complications, today’s legal climate does not allow the more cost-effective treatment
protocols used in other countries. Back to Index.
Thrombolytics
WHICH thrombolytic is used is infinitely less important
than that a thrombolytic IS given, and as early as possible. The physician should usually
make the decision to use thrombolytics within 20 minutes of the patient’s arrival.
The physician can obtain the chest pain history while the
treatment team places the patient on oxygen, cardiac monitor, and IV. This initial history
includes specific questions about contraindications to thrombolytics.
Obtain the ECG when it can be done without getting in the
way of basic stabilization, usually within three minutes of arrival. Meantime, the
physician is examining the patient.
Give nitroglycerin when vital signs have been obtained. By
the third nitroglycerin dose, the physician is ready to order the thrombolytic. Back to Index.
Back to Main Manual Index.
Copyright 1996 Mad Scientist Software
Citation:
Argyle, B., Chest Pain Simulator Computer Program Manual.
Mad Scientist Software, Alpine UT, 1996.