THE DIFFERENTIAL DIAGNOSIS OF

LOBAR PNEUMONIA.

BY

HEINRICH STERN, M. D., New York.

INTRODUCTORY.

The symptom-complex constituting lobar pneumonia is quite characteristic; the recognition of the affection-provided the case has been under observation from the onset is hardly ever attended by any difficulty. Occasional delay in arriving at a conclusive diagnosis may ensue in such instances of the disease which have not been under medical supervision from the start and do not give a thoroughly reliable history; however, on the hand of the physical signs together with the special objective phenomena chancing to be present at the time, a positive diagnosis will soon be established in the overwhelming majority of the

cases.

The fact, furthermore, must not be lost sight of that the classical syndrome of lobar pneumonia is not always present in its entirety. One or the other of the typical local or general symptoms or physical signs may be illy developed or be absent altogether; in one-fifth of the cases the initial rigor has never occurred; the pain, depending almost entirely upon the degree of associated pleural involvement, may be a negligible factor when the process is a deep-seated one; a mild temperature elevation may be out of proportion to the severity of the case; even the characteristic pulserespiration ratio may be entirely wanting. The physical signs may fail if the pneumonic process has not progressed towards the periphery of the lung, if there prevails an additional intrathoracic disease or if there exists a much thickened pleura.

Certain cases of pneumonia are apt to be mistaken for one or the other pathological condition which is not localized in the thoracic cavity. This may especially occur with typhoid fever and meningitis.

Symptoms analogous to those of the typhoid state dry tongue, rapid pulse, feeble heart action, diarrhea, great weakness, etc. -may prevail in protracted cases of lobar pneumonia. If a case has not been under observation prior to the occurrence of this condition, which is known as typhoid pneumonia, it may be at times a difficult task to ascertain its real character. If in such a case a careful physical examination does not point to the lung as the seat of the affection the application of the Widal test will clear the diagnosis in well-nigh every instance. Again, there occur cases of typhoid fever-pneumo typhoid-the inaugural symptoms of which more or less resemble those of lobar pneumonia. The positive Widal reaction points to typhoid fever as does the characteristic eruption. which usually appears on or about the eighth day.

In children particularly, lobar pneumonia may be mistaken for meningitis. A careful physical examination, however, will often demonstrate the presence of pneumonia. Cytologic study of the spinal fluid may determine the occurrence of meningitis. Convulsions may occur in pneumonia as well as in meningitis; in small children, however, pneumonia is frequently ushered in with a convulsion while this commonly ensues somewhat later in meningitis. Headache in pneumonia is frontal, in meningitis it is occipital and accompanied by painful retractions of the muscles of the neck. Absence of Kernig's sign in pneumonia, nonoccurrence of a crisis in meningitis, and the presence of the characteristic pulse-re

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Complete Series, Vol. XVI.

In the presence of chronic alcoholism violent mental manifestations may entirely overshadow the local condition. On the hand of the physical signs and the objective symptoms a conclusive diagnosis of lobar pneumonia should be established within a few hours after its onset in the chronic

drunkard. Again, an acute pneumonic process, remaining often unrecognized, is frequently the terminal affection of many a chronic disease; the association of fever and cough superimposed upon a chronic glycosuric, nephritic or cardiopathic state should invariably prompt a thorough examination of the lungs. The differential diagnosis between the manifestations of the chronic and those of the acute complicating process is possible in a goodly proportion of the cases.

The differential diagnosis of lobar pneumonia is almost entirely confined to the latter's differentiation from other acute diseases of the lungs or from those of the pleura during the course of which there ensues pulmonary dulness. A study of the differential diagnosis of lobar pneumonia should therefore comprise not only diseases like acute pneumonic phthisis, bronchopneumonia, pleurisy with effusion and hemorrhagic infarct, but also affections of possibly less acuity, as hydrothorax, pneumothorax, atelectasis and hypostatic pneumonia, which are characterized by dulness most frequently elicited over the lower lung portions. In the following the various diseases are analyzed on the hand of their physical signs and symptomatology.

INSPECTION, MENSURATION. Lobar Pneumonia. Intercostal spaces usually remain unchanged; more or less.

creased expansive motions of chest on sound side; pulsation of diseased lung apt to give rise to distinct movement of chest wall; little or no increase in volume of affected side.

Acute Pneumonic Phthisis. Rapid respiratory movements; nothing pathognomonic.

Acute Pleurisy with Effusion. Intercostal spaces obliterated or bulging on affected side; increase of circumference noticeable in many cases; respiratory sluggishness in diseased area; in effusion of right side displacement of apex beat to left, in effusion of left side displacement to the right or obliteration.

Broncho-Pneumonia. Nothing charac

teristic.

Hemorrhagic Infarct. Nothing characteristic.

Hydrothorax. Intercostal spaces never bulging; usually no thoracic enlargement.

Pneumothorax. Conspicuous enlargement and immobility of affected side; intercostal spaces distended and bulging; apex beat obliterated in affection of left side, displaced to left in affection of right side; patient lies on affected side.

Atelectasis. During inspiration often retraction over affected area.

Hypostatic Pneumonia. Nothing characteristic.

PALPATION.

Lobar Pneumonia. Vocal fremitus generally increased over area of dulness; pressure sensitiveness of intercostal spaces on affected side.

Acute Pneumonic Phthisis. Occasionally bronchial fremitus; vocal fremitus decreased when accompanied by pleurisy.

Acute Pleurisy with Effusion. Vocal fremitus over area of dulness decreased or abolished; when pulmonary and costal pleura are connected by adhesions vocal fremitus may be obtained.

Lobar Pneumonia. Stage of engorgement: Percussion note generally higher pitched, often tympanitic. Stage of hepatization: Percussion note dull, ranging from sound of more or less tympanitic timbre to decided flatness; dulness has not character of wooden flatness of effusion; sense of resistance not so great as in pleurisy with effusion. Stage of resolution: Dulness subsides; percussion note at first somewhat tympanitic, may remain higher pitched over affected side for some time.

Acute Pneumonic Phthisis. Impaired percussion note or dulness as a rule; in some cases hyper-resonance.

Acute Pleurisy with Effusion. Dulness over accumulated effusion; its degree depends upon amount of effusion and displacement of lung from costal pleura; dulness begins over posterior and inferior portions of lung and ascends in accordance with increase of effusion. Effusions amounting to less than 300 cc. are not demonstrable by percussion. Intensity of dulness and sense of resistance when percussing increased downwardly; limit of dulness higher in sitting than in recumbent posture; when effusion is copious cracket-pot sound may be educed below clavicle; if pleural cavity is partly filled with exudation line of dulness changes when occupying different position. Broncho-Pneumonia. Small, circumscribed areas of dulness, often bilateral; dul

ness not marked and often demonstrable by slight percussion only; often it is diffuse exhibiting some tympanitic quality, especially over lower lobes.

Hemorrhagic Infarct. Circumscribed dulness of slight intensity, mostly over lower lobe and unilateral.

Hydrothorax. Dulness over accumulated liquid, mostly bilateral; line of dulness ascends and descends during respiration; when unilateral dulness is usually elicited over right side.

Pneumothorax.

Percussion note deep and full or flat tympanitic in some cases, in others dull; dulness over effusion at base changing outline with postural change of patient; movable dulness more readily elicited than in pleurisy.

Atelectasis. Irregular, not sharply circumscribed area of dulness when condition is extensive, tympanitic sound when incomplete or slight; postural change of patient and deep inspiration cause disappearance of dulness or tympany.

Hypostatic Pneumonia. At onset abbreviated percussion note with tympanitic timbre behind, below or lateral; later dulness, absolute below, gradually clearing upwards.

AUSCULTATION.

Lobar Pneumonia. Stage of engorgement: Weak respiratory sounds in affected part, exaggerated breathing over healthy portions; broncho-vesicular portions; occasionally

sounds on full inspiration; at end of deep. inspiration fine crepitant râle. Stage of hepatization: When dulness is marked lowheard first with expiration; crepitant râle at pitched bronchial or tubular breathing, end of inspiration best audible at beginning of consolidation; subcrepitant râles are due to accompanying bronchitis; tubular breathing absent in certain cases of massive pneumonia; occasional friction-sounds. Stage of resolution: Subcrepitant râles audible on inspiration and expiration, coarser râles over bronchi; broncho-vesicular breathing followed by normal respiratory sounds.Auscultation of voice elicits normal transmission (bronchophony), occasionally in

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Acute Pneumonic Phthisis. Sibilant and coarse or small, fine, crepitant, dry or moist râles; in children occasionally highpitched tubular breathing at bases of lung.

Acute Pleurisy with Effusion. Weakened vesicular breathing in presence of slight effusion; breathing sounds inaudible in presence of considerable effusion; distinct bronchial breathing, best audible near spine when lung is compressed and layer of exudate between lung and chest-wall is moderate; bronchial breathing, in contradistinction to pneumonia, least audible over area of marked dulness, i. e. at base of effusion. Leathery friction rub at onset of affection prior to accumulation of effusion, later frequently over upper level of exudate. -Vocal resonance diminished or absent; occasionally egophony; whispered voice transmitted through serous, not through purulent exudate (Baccelli's sign).

Broncho-Pneumonia. Over areas of dulness, fine, subcrepitant râles, often bilateral; respiratory murmur bronchial or bronchovesicular; also manifestations of bronchiolitis. Bronchophony over larger areas of dulness.

Hemorrhagic Infarct. Bronchial breathing, moist râles; occasionally pleuritic friction.

Hydrothorax. Respiratory murmur over dulness weakened or absent, occasionally bronchial between scapulae; friction sounds only when complicated with pleurisy. Vocal resonance sometimes egophonic over boundary line of dulness.

Pneumothorax. Respiratory murmur over diseased side weakened or absent; amphoric breathing in presence of open pneumothorax, exaggerated breath-sounds on healthy side; metallic quality of râles; metallic tinkling on coughing or deep inspiration. Hippocratic succussion elicited in most cases (production of metallic splashing sound by shaking patient's body); coin sound characteristic of condition.

Atelectasis. When incomplete, vesicular murmur diminished or absent; when involved area is large, bronchial respiration;

Bronchophony as a rule.

Lobar Pneumonia. No or no marked displacement of either organ.

Acute Pneumonic Phthisis. No displacement of either organ unless accompanied by pleurisy with effusion.

Acute Pleurisy with Effusion. When exudate is on right side heart is displaced to left, liver, especially right lobe, downward so that it is readily palpable; when exudate is on left side heart is displaced to right.

Broncho-Pneumonia. No displacement of either organ.

Hemorrhagic Infarct. No displacement of either organ.

Hydrothorax. No cardiac displacement in bilateral hydrothorax; liver frequently displaced downward.

Pneumothorax. When left side is affected ordinarily absence of dulness in normal cardiac area, especially when patient. is in recumbent position; spleen dislocated downward; in disease of right side heart pushed toward left, liver downward.

Atelectasis. No displacement of either

organ.

Hypostatic Pneumonia. No displacement of either organ.

TEMPERATURE.

Lobar Pneumonia. Sudden initial chill, temperature rising to 104 deg. or 105 deg. F. in 8 to 12 hours; assumes then continued form, nocturnal remissions of I deg. or more; in weakened persons, advanced age, alcoholism lower average temperature. During pseudo crisis marked temperature decline followed by renewed elevation; crisis usually between 5th and 11th day,

tension reduced; occasionally irregularity of rhythm.

temperature falling during night; postcritical temperature often subnormal.

Acute Pneumonic Phthisis. Rapidly rises to 104 deg. or 105 deg. F.; continued type, or soon remittent or hectic with nightsweats. Onset in other cases with repeated chills, followed by high and irregular fever; no crisis.

Acute Pleurisy with Effusion. Rises slowly to 101.5 deg. to 103 deg. F.; after from 1 to 3 weeks declines by lysis, never by crisis; in most acute cases assumes continued character; surface temperature I to 2 degrees higher on affected than on healthy side.

Broncho-Pneumonia. Abrupt or gradual increase to 102 deg. to 104 deg. F.; fever irregular, in severe cases continued; declines by lysis.

Hemorrhagic Infarct. Chills and fever frequently at onset; no temperature elevation later on, as a rule; increase or continuation of initial fever due to septic processes.

Hydrothorax. Usually no elevation.

Pneumothorax. Depending upon primary disease; at onset often subnormal; increases when exudate is produced.

Atelectasis. Dependent upon primary disease.

Hypostatic Pneumonia. No characteristic temperature range; depending entirely upon primary disease.

Broncho-Pneumonia. Pulse-rate very frequent; compressible; in later stages often extremely rapid, feeble and arrhythmic. Hemorrhagic Infarct. Small and fre

quent.

Hydrothorax. Feeble.

Pneumothorax. Small, compressible, ac

celerated.

Atelectasis. Small, feeble, accelerated. Hypostatic Pneumonia. Small, accelerated.

SPUTUM.

scanty,

Lobar Pneumonia. At first colorless and frothy, soon attains characteristic rusty or prune juice color; viscid and very tenacious, difficult to eject by patient; adherent to receptacle; more profuse, also purulent, easier expelled at period of crisis; may be absent in children and old people. Contains often fibrin clots; microscopically consists of red and white blood cells. mucous and pus corpuscles, bronchial and alveolar epithelium, blood pigment, small cell casts of alveoli, fibrinous casts of bronchioles of microorganisms, pneumococcus generally, micrococcus lanceolatus and influenza bacillus occasionally present.

Acute Pneumonic Phthisis. At first mucoid, then rusty-colored; later more abundant, muco-purulent, greenish or bluish-yellow; contains tubercle bacilli and shreds of yellow elastic tissue.

Acute Pleurisy with Effusion. Frequently no expectoration; mucous excretion. during process of resorption; if abundant generally due to concurring bronchitis or pulmonary tuberculosis.

Broncho-Pneumonia. Glairy and tenacious mucus ordinarily, occasionally mucopurulent and rather turbid; in adults may be blood-tinged; never rusty.

Hemorrhagic Infarct. Bloody, darkcolored, mucoid expectoration appearing suddenly.

Hydrothorax. Only in presence of complications.