Chapter 2 Vital Signs
Sir William Osler, JAMA 26:999, 1896.
“A quartan fever kills old men and heals young.” — Italian proverb
Generalities
C. Temperature
5 Are there any other conditions that can alter oral temperature?
Beside tachypnea (which decreases oral temperature by 0.5°C for every 10 breaths/minute increase in respiratory rate), recent ingestion of cold or hot substances (including smoking a cigarette) may also change it—something well known to anyone who ever tried to play hooky from school (see factitious fever in question 17).
8 How long does it take for a thermometer to equilibrate when placed under the tongue?
Three minutes with the old mercury thermometers, and around one with the newest models.
10 What are the most commonly encountered fever patterns?
Sustained or continued (little variability from day to day): This used to be the pattern of lobar pneumonia, steady until abruptly resolving by either crisis or death. Nowadays, a sustained pattern is mostly seen in gram-negative sepsis, but also in central nervous system (CNS) diseases.
Intermittent: With complete resolution between episodes (see later)
Remittent: Abating every day, but still not completely resolving. This used to be the pattern of typhoid fever.
Relapsing: With a series of febrile attacks, each lasting several days, and all separated by afebrile intervals of about the same length. A relapsing fever is usually infectious (brucellosis, borreliosis, or relapsing typhoid, but also tuberculosis [TB]), but can occur in Hodgkin’s, too, or familial Mediterranean fever.
11 What are the most common fever types?
It might also suggest a noninfectious etiology, such as an occult neoplasm or autoimmune disease.
12 What are the main types of “intermittent” fever?
Quotidian fever: From the Latin quotidianus, daily. This is a fever whose paroxysm (and resolution) occurs every day. It is usually caused by a double tertian malaria, due to infection by two distinct groups of Plasmodium vivax, alternately sporulating every 48 hours. It may also be caused by the most pernicious malarial parasite (P. falciparum), combined with vivax, or by two distinct falciparum generations that mature on different days, thus resulting in a fever that occurs twice a day. Note that a double quotidian fever is a daily two-spikes fever that is not malarial, but gonococcal. It used to be present in 50% of endocarditis cases, but today is mostly extinct.
Tertian fever: From the Latin tertianus, third. This is a P. vivax fever that recurs every third day, counting the day of an episode as the first. Hence, it occurs every 48 hours (every other day).
Quartan fever: From the Latin quartanus, fourth. This is a P. malariae fever that recurs every fourth day, counting the day of an episode as the first. Hence, it occurs every 72 hours. Note that a double quartan is instead an infection with two independent groups of quartan parasites, so that the febrile paroxysms occur on two successive days, followed by one without fever.
Malignant tertian fever: This is the fever of P. falciparum (falciparum fever, or aestivo-autumnal fever, or Roman fever because it was a common ailment in the countryside of Rome up to World War II). It is characterized by 48-hour paroxysms of a severe form of malaria, occurring with acute cerebral, renal, or gastrointestinal manifestations. These are usually due to clumping of the infected red blood cells, causing secondary capillary obstruction and ischemia.
18 Are there any other terms in this alphabet soup of “fevers”?
Quite a few, once again primarily of historic value. For a smorgasbord:
Ephemeral fever: A febrile episode lasting only a day or two
Epimastical fever: From the Greek epakmastikos, coming to a height. A fever that increases steadily until reaching an acme, and then declines by crisis or lysis (crisis indicates a sudden drop, whereas lysis indicates a more gradual defervescence).
Exanthematous fever: A fever associated with an exanthem, i.e., a skin rash
Fatigue (exhaustion) fever: An elevation of body temperature that follows excessive and continued muscular exertion. It may last sometimes for up to several days.
Miliary fever: An infectious fever characterized by profuse sweating and the production of sudamina (i.e., minute vesicles of fluid retention in sweat follicles, a.k.a. “milia”). Typical of past epidemics.
Monoleptic fever: A continued fever that has only one paroxysm
Polyleptic fever: From the Greek poly (multiple) and lepsis (paroxysm). A fever that occurs in two or more paroxysms, as typically seen in malaria.
Undulant fever: The long and wavy temperature curve of brucellosis
24 What other physical findings may help identify the cause of a fever?
Anhidrosis argues in favor of either heat stroke or drugs interfering with diaphoresis.
Muscle rigidity suggests neuroleptic malignant syndrome or malignant hyperthermia.
Jaundice may be seen in bacterial infections, independent of their direct involvement of the hepatobiliary system (such as cholangitis or hepatitis, see question 14).
Shaking chills argue only modestly in favor of bacteremia. Conversely:
26 What are the causes of hypothermia?
Various. Based on its mechanism, hypothermia is usually classified as:
27 What are the signs and symptoms of hypothermia?
They vary, depending on the degree of hypothermia and the type of underlying disorder (a stroke, for example, may obscure the signs of hypothermia). Moreover, symptoms and signs are often a continuum, and there is major variability among patients (Table 2-1).
Mild Hypothermia | Moderate Hypothermia | Severe Hypothermia |
---|---|---|
Confusion | Level of consciousness diminishes | Unresponsiveness or coma |
Tachypnea | Delirium | May appear dead* |
Tachycardia | Bradycardia | Loss of reflexes |
Vasoconstriction | Bradypnea | Very cold skin |
Lethargy | Shivering stops | Hypotension |
Shivering | Reflexes slowed | Pulmonary edema |
Ataxia | Cold diuresis | Respiratory failure |
Dysarthria | Profound acidemia and ventricular fibrillation | |
Loss of fine motor coordination |
* Hence, you are never dead until you are warm and dead (see Chapter 20, Coma).
D. Heart Rate and Rhythm
29 How should the pulse be examined?
It depends. If you are simply assessing rate and rhythm, the best (and most accurate) technique is to count the pulse at the wrist for 30 seconds, and then double the figure. Alternatively, you could count the apical rate, which is more accurate in situations of pronounced tachycardia, especially atrial fibrillation (where pulse deficit commonly occurs). In this case, counting 60 seconds may further improve accuracy. Finally, if you want to assess the characteristics of the waveform, then you should assess the pulse of a central artery (see Chapter 10, questions 3–56).
34 What bedside information can help to evaluate an arrhythmia?
In times of electrocardiograms (ECGs), it seems almost anachronistic to discuss the physical examination of arrhythmias. Yet a thorough and astute exam, comprising an assessment of arterial pulse (especially when coordinated with apical impulse—see pulse deficit in question 30), venous waveform, and characteristics of heart sounds, can often deliver a diagnosis.
35 What are the features of the pulse one should consider when evaluating arrhythmias?
Its regularity (or lack thereof) and its response to vagal maneuvers. In this regard:
A regularly irregular tachycardia is a sign of bigeminy or trigeminy. But it can also indicate atrial flutter with variable atrioventricular block (in this case, look for flutter waves in the neck veins) or a second-degree heart block in which skipped beats occur at regular intervals.
An irregularly irregular tachycardia is most commonly seen in atrial fibrillation. This is differentiated from frequent premature contractions because the latter may present with occasional cannon “A” waves (see Chapter 10, questions 78–88).
A regularly regular tachycardia can be due to atrial flutter (with constant A-V block), paroxysmal atrial tachycardia, ventricular tachycardia, and, of course, sinus tachycardia. Response to vagal maneuvers might be helpful in separating these entities.
A tachycardia that resolves abruptly after either Valsalva’s maneuver or carotid artery massage is a paroxysmal atrial tachycardia (typically associated with a unique feeling of “pounding in the neck” due to the simultaneous occurrence of carotid pulsations and cannon “A” waves).
One that only slows down is usually sinus tachycardia.
One that halves in rate is typically atrial flutter.
Ventricular tachycardia is usually unchanged by vagal maneuvers. Ventricular tachycardia, however, typically presents with findings of atrioventricular dissociation, such as cannon “A” waves, and variable intensity of S1.
36 What other findings might help to recognize an arrhythmia?
The presence and characteristics of a pause between heartbeats. A pause preceded by a premature beat, for example, usually indicates an atrial (or a ventricular) premature contraction, whereas one not preceded by a premature beat usually indicates a heart block.
A premature beat associated with a cannon “A” wave on venous exam (see Chapter 10, questions 86 and 87) usually indicates an atrial contraction against a closed tricuspid valve and, therefore, a ventricular rather than an atrial premature contraction. Cannon “A” waves might also consistently occur in paroxysmal atrial tachycardia due to the almost simultaneous contraction of atria and ventricles in this condition. Conversely, they might occur randomly in complete heart block.
A very loud, almost “cannon-like,” S1 occurring at times in patients with regular rhythm usually suggests the coincidental contraction of atria just before ventricles. This argues in favor of an escape ventricular rhythm from complete heart block.
A “regular” pulse deficit (for example, a rate at the wrist that is exactly half of that at the apex) argues in favor of bigeminy, with the premature beats being always unable to achieve ejection. This needs to be differentiated from pulsus alternans (see Chapter 10, question 23).
E. Blood Pressure
39 What does sphygmomanometer mean?
It is Greek for “measure of a weak pulse” (sphygmos, pulse; manos, scanty; metron, measure).