Ultrasound, a Tool for the Clinical Examination
The Abdominal Level
A peritoneal effusion is promptly detected, long before dullness of the flanks appears.
Prompt identification of diffuse air artifacts replaces the clinical search for tympanism.
Visualization of peristalsis makes the search for air–fluid sounds unnecessary – a sign that may be of low sensitivity.
The often difficult search for a hepatomegaly is replaced by the direct ultrasound detection of an enlarged liver, which can also reveal its origin (tumor, abscess, right heart failure, etc.).
An area that is sensitive to palpation (or echopalpation) will reveal the cause: parenchyma abscess, cholecystitis.
The search for pain from the shaking of the liver no longer has a raison d’être if a liver abscess has been identified, and the patient will be grateful to us!
Going farther, we could say that the free hand of the operator can also evaluate abdomen supple- ness or, on the other hand, parietal contraction.
The Thoracic Level
The basic elements of lung examination, i.e., inspection, palpation, percussion, auscultation, are reinforced if ultrasound detects pneumothorax, pleural effusion or alveolar consolidation. As regards interstitial syndrome, only ultrasound can recognize it, as there is no clinical equivalent.
A heart analysis informs immediately on the pulse and contractility. This may rejuvenate the search for muffling of heart sounds or galloping rhythm. A vegetation may be detected whether or not there is heart murmur. Regardless of whether there is pericardial rubbing (precisely the main feature of substantial effusions), pericardial effu- sion, its tolerance, and sometimes its origin can be recognized at the same time.
Ultrasound cannot and must not replace the phys- ical examination. It is not conceivable to practice ultrasound before having clinically examined the patient. However, in emergency medicine, one absolute aim is to proceed quickly and accurately.
We can therefore meditate on ultrasound’s capa- bility to extend, not to say surpass, the physical examination in certain instances.
The physical examination has critical advan- tages (no cost, innocuousness, etc.) but also some limitations, all the more worrying as we are exam- ining a critically ill patient. Pulmonary edema without crackles, hemoperitoneum without pro- voked pain, venous thrombosis without clinical signs, urinary obstacle without pain, or, more sim- ply, all the difficulties arising from an examination performed in obese or ventilated, sedated patients are situations where the physical examination can show itself to be insufficient. In addition, the infor- mation obtained from years of training is immedi- ately confirmed – or refuted – when the intensivist holds the ultrasound probe.
Let us consider the ultrasound device as if it was a clinical tool, a kind of stethoscope.
Half of the work will be done if one considers that an examination performed at the bedside is a clinical examination, in the etymological sense.
The other half will be achieved if one looks into the meaning of the word »stethoscope«, which comes from the Greek and was created by a French physi- cian at the beginning of the nineteenth century.
This instrument, which has symbolized medicine for nearly 200 years, strictly means »to observe throughout the chest wall«.
Considering ultrasound an extension of the physical examination is becoming widespread. Let us make a brief overview of the services ultra- sound can offer when considered this way.
CHAPTER 30
Infinite examples can be cited. Detection of a cardiac liver and of jugular turgescence are redun- dant with the existence of right chambers dilata- tion, provided they are not compressed by a peri- cardial tamponade.
The diagnosis of dehydration can be clinically delicate. It is reinforced by the detection of col- lapsed venous trunks (inferior vena cava) or heart chambers and a dry lung surface, without intersti- tial changes.
Certain physical signs such as the increase in precordial dullness belong to the past since ultra- sound has entered the emergency setting.
At the thoracoabdominal junction, several combinations can be imagined: a painful right hypochondrium indicates an acute cardiac liver;
moving the probe then reveals enlarged right chambers; a shift of the probe at the venous level (e.g., iliofemoral) then detects the venous thrombosis that was responsible for the previous disorders.
The Peripheral Level
A rapid scan along the lower and upper venous axes easily rules out the threat of thrombosis.
The behavior of the femoral artery, when com- pressed by the probe against the bone, can give another view on arterial pressure. When arterial pressure is normal, the compression does not affect the cross-section. Progressively, the lumen collapses, with systolic expansion despite the probe pressure. At an even lower stage, the artery collapses without resistance.
Occult parietal emphysema can give early ultra- sound signs.
Serendipitous Applications
An important advantage of ultrasound (which can, like any device, break down) is that it allows the clinicians to improve their accuracy in the physical examination. It is indeed possible to assess one’s clinical skill in real-time. For example, pleuritic murmur can be compared with ultrasound pleural effusion. This could be repeated with a variety of clinical signs.
Comparing chest X-ray and ultrasound can also provide the same critical reading of the chest radi- ography (assuming that ultrasound is a gold stan- dard).
And the Clinical Examination?
All the examples seen above are but a few of the countless situations where ultrasound performs better than the physical examination. Should we therefore mistrust our hands, eyes and ears? In other words, should we dispense with the clinical examination? Does opposing physical examina- tion and bedside ultrasound make any sense? In the extreme emergency or if overburdened, many items of the physical examination will be redun- dant and therefore waste time. In these precise sit- uations, we do not hesitate to use ultrasound first.
In calmer situations, one must absolutely proceed as usual. However, we must admit frankly that when we do not have our ultrasound unit with us, we feel extremely blind.
The truth may be that we see patients very early in an emergency situation, and this can be a source of great disparity between the signs we learned at school and what we see in the ER or ICU. Ultra- sound is accused of being highly operator-depen- dent. This is probably true, but the physical exami- nation may be even more operator-dependent.
Physical examination can be considered a complex and uncertain field. Diagnoses such as early blad- der distension or pleural effusion can be recog- nized by well-trained, intelligent hands, after a long training period. Yet these diagnoses are reached much more rapidly using ultrasound. This critical point has not been sufficiently documented.
Several physical signs will obviously never be replaced by ultrasound, particularly inspection (habitus, skin, etc.) and neurological examination.
Indeed, where is the harm in placing a mechanical probe
1over the tibia in order to explore deep sen- sitivity, thus leaving the cumbersome tuning fork in the attic?
In addition, the physical examination remains an important psychological step. This direct con- tact between the physician and the highly stressed patient should unconditionally be preserved. Ultra- sound is an opportunity for the radiologist to get even closer to the patient.
We will close this chapter with a thought to our elders. The physical examination was their only diagnostic tool, and they knew (at least the most famous among them) better than us how to exploit its numerous subtleties and secrets.
And the Clinical Examination? 187
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