A middle-aged man hospitalized for intensive pulmonary toilet

HISTORY

A middle-aged man hospitalized for intensive pulmonary toilet and topical and systemic treatment of a refractory skin disorder. Cough and moderate dyspnea with even mild exertion. Complains of scaling, uncomfortable dermopathy that he finds deeply cosmetically disfiguring and emotionally distressing.

PHYSICAL EXAMINATION

General appearance as depicted. Vital signs: temperature, 37°C (98.6°F); heart rate, 82 beats per minute and regular; respiration rate, 12 breaths per minute; blood pressure, 136/84 mm Hg. Skin as shown.

This man is attached to a nasal oxygen delivery device. Self-evident as that may be, the hardware must be acknowledged if it is to figure in planning his management. If this man has home oxygen therapy--and a third party is paying for it--he must have met criteria for severe respiratory dysfunction with a low arterial PO₂ and/or a low SaO₂, especially with exercise. If we wonder whether, in that case, he would have to be dyspneic at rest, the answer, much more frequently appreciated in the era of the pulse oximeter, is thatmarked hypoxia may be surprisingly well tolerated. There may or may not be tachypnea, which some pulmonologists will cite as evidence of lung stiffness. Optimal breathing in obstructive airways disease is ideally slower than in controls, so a low respiratory rate is appropriate. The effect of tachypnea on minute ventilation in this setting would be at best a mixed blessing.

In the absence of prominent or new symptoms, cardiac dysfunction is unlikely to be the cause of hypoxemia, although the question of concurrent heart and lung disease with a final common pathway of dyspnea is always raised. The results of pulse oximetry--called "pox" readings by many practitioners--will not distinguish the two causes, and apart from a telling history and distinctive findings on physical examination of heart and lungs, the echocardiogram and the chest radiograph remain vital in making the distinction.

A key bedside observation in establishing severity, if not cause, is the position in which this patient holds his trunk--upright and supported with both arms. This position is favored by persons with lung disease, especially obstructive airways disease.

"PROFESSORIAL POSITION" AND BREATH SIGNS

Because of the way the patient holds his body, he forms a tripod when standing or seated, and thus is said to display the tripod sign.¹ In utter exhaustion, just before death from airways disease, a patient may assume a position on all fours that also feels, perhaps in an analogous way but with the trunk held horizontal, optimal for airway flow dynamics, and without the compression effect of the trunk's weight against the mattress (or that of any adducted limb).

In the less drastic so-called professorial position shown here, the mechanics of the upright to forward-tilted chest apparently optimize air exchange and airflow despite advanced airways obstruction. The sign may also be noted in a patient with asthma who has discovered the position and uses it during a severe attack. Most commonly, as here, it occurs in long-standing, debilitating emphysema, although it might also be observed in severe dyspnea from any cause.

It is extraordinary that although the professorial position and the tripod sign have been well known for many decades, a search of PubMed yielded no specific study. One finds only sparse anecdotal accounts. In one of these, polio was regarded as clinically ruled out in children during a polio epidemic if they could kiss their knees (presumably showing motor function to flex hip, knee, and trunk) and did not have a tripod sign.² Another paper describes the posture but does not name the sign.³ Here is yet another instance of old knowledge that has not been tested to see whether it will hold up under scrutiny and thus have a chance of becoming--to use what is now a cliché--evidence-based.

PREDICTIVE VALUE OF PHYSICAL SIGNS IN OBSTRUCTIVE AIRWAYS DISEASE

Although information is lacking on the predictive value of the tripod sign and of the professorial position, other signs of airways obstruction have been studied.^4-7 Most reflect air trapping, which is a dynamic phenomenon but varies only to a slight degree during the respiratory cycle; it is present in clinically stable emphysema. Thus, hyperresonance to percussion and regionally or globally attenuated breath sounds cannot independently show that airflow is acutely reduced.

There is a correlative bedside sign: the time required to complete a deep forced expiration. Obstruction may be inferred if the duration is longer than 6 seconds.⁸ One starts from a slow maximal inspiration, and proceeds until the expiratory sound is no longer heard through the stethoscope bell held over the trachea.

Forced expiratory wheezing as a sign of airways obstruction, by contrast, has shown neither sensitivity nor specificity sufficient to justify its routine use.⁹ Spirometry and formal pulmonary function tests, the latter performed in a laboratory, clearly elucidate the physiology and its derangement but are not screening instruments; rather, they serve best in well-chosen cases that are either clinically confusing or in need of quantitation (eg, before anticipated pulmonary lobectomy or pneumonectomy). It would be interesting to see whether the prognosis for survival in chronic obstructive pulmonary disease could be stratified equally well without them.

DIFFUSE ERYTHRODERMA AND SCALING

The patient has a second striking abnormality: diffuse erythroderma with relatively minor scaling. One does not see the familiar silver scales of classic psoriasis or the yellow, pasty lesions of pustular psoriasis; this may be because of the benefit of his intense antipsoriatic regimen. Even slight scaling, in the right context, strongly hints at psoriasis. In general, the dark red and somewhat glistening look suggests the beneficial effects of topical antipsoriatic therapy. In fact, the photograph was taken several days into a hospital stay precisely for intense topical and systemic therapy, and the skin had already improved substantially.

TATTOO

The tattoo that seems to depict a dragon, which in this patient's age cohort has a different prevalence and import than in, say, today's 20-somethings, affords a bit of insight. It may be a sign of ongoing rebellion or of being an aging motorcycle gang member, or it might merely mark a period in military service. Associated medical concerns include the prospects of transmission of hepatitis viruses and HIV via the tattoo needle or by sexual behavior or drug use during the same period. Because this tattoo was acquired in the 1950s, HIV is out of the question--unless contracted in the interval.

SUBCUTANEOUS LIPOMA OF THE LEFT SCAPULA

A further observation was of a lump beside the left shoulder blade. Clearly, this had no bearing on the patient's systemic health, unless one wanted to speculate (wildly improbably) about a lung cancer with a subcutaneous metastasis. One would expect, with a lipoma, free mobility of the overlying skin and subjacent fascia, and a texture on palpation that might be anything from "soft as butter" to firmer and more fibrous. These attributes and a history of neither rapid growth nor huge size would minimize the likelihood of a sarcoma.

Conventional lipomas and fibrolipomas (the firmer variant) can grow immense; when they do so, removal becomes an ever better idea: one can then exclude malignancy by histopathologic evaluation and, if sarcoma is found, therapy is already well under way.

A LITTLE CHALLENGE

I ask readers of this column to send an e-mail (addressed to the editor, JBowen@cmp.com) if they spot any further physical findings in this photograph, if they draw different inferences from them, or if they are aware of literature on the professorial position or the tripod sign that has not been indexed in PubMed. Although this is no April Fool's joke, and no "hidden finding" exists to my knowledge, I would not be surprised if further information could be extracted from this image. As I look for the hundredth time, for example, I wonder if the lighter-looking hair is native and the jet black hair a wig--not a medical concern, but part of the clinician's joy in discovering the hidden as well as the evident.

Schneiderman H. Severe obstructive airways disease with the professorial position/tripod sign and with unrelated erythroderma, tattoo, and lipoma. CONSULTANT. 2007;47: 485-488.