(1)
Hôpital Ambroise Paré Service de Réanimation Médicale, Boulogne (Paris-West University), France
Electronic supplementary material
The online version of this chapter (doi:10.1007/978-3-319-15371-1_34) contains supplementary material, which is available to authorized users.
The present textbook is labelled Lung Ultrasound in the Critically Ill. This respects the trust that the community shows to our few publications. This also limits us to lecture quite only on this restricted topic. We have the feeling that the whole body can benefit from the same approach, mainly by using a single probe with equivalent results.
We will be brief: the 2010 edition contains all details, there is not much to add.
Some figures shown here have all been taken using our Japanese 5 MHz microconvex probe.
Basics of Critical Abdomen
Most acute abdominal disorders can be detected using ultrasound, usually superior to plain abdomen radiographies. It is often able to replace CT for indicating prompt surgery. In a few lines (see 2010 edition for details), we expose the main problem. Twenty organs, 20 diseases per organ: This is ultrasound, i.e., this traditional, expert, operator-dependent world. We know that many emergency physicians have used a lot of energy for investing in this hard field, and, today, we assume each reader is at ease with some diagnoses, such as fluid in the abdomen, kidney dilatation, bladder distension, aortic aneurism, etc.
How to make a logical presentation of abdominal ultrasound? Using frequency? Severity of the diseases? Anatomic classification (from outside to inside for instance)? Why not alphabetic order (aorta, bladder, colon, duodenum, etc.)? We will just, in this small paragraph within a small chapter, show some of the diseases which are the most severe and the less known by the radiologists, in an order less than academic.
Pneumoperitoneum
We aimed at describing signs more standardized than just “gas barriers at the abdomen.” In a very few words, it shows the same logic as pneumothorax. The physiological peritoneal sliding is abolished (with a stratospheric pattern on M-mode) (Video 34.1). Our study showed a 100 % sensitivity and a 92 % specificity [1]. Below the peritoneal line are only artifacts, like A-lines (and Z-lines too), called GA-lines (and GZ-lines) since they do not arise from the pleural line. GA-lines are observed with a 100 % sensitivity. At the periphery, a “gut point,” equivalent to the lung point, is found in 50 % of the cases. Gut sliding, splanchnogram (vision of abdominal viscera), and GB-lines (equivalent of lung B-lines) rule out pneumoperitoneum. See more details in the caption for Fig. 34.1.
Fig. 34.1
Pneumoperitoneum. The free gas collects at nondependent areas, making the diagnosis accessible. Gut sliding is the label we give to the respiratory dynamic of the visceral layer against the parietal layer: an equivalent of the seashore sign (see Fig. 5.12 of 2010 edition). The splanchnogram is how we called the detection of real, not artifactual structures (liver, bowel loops, etc.), showing that there is no free gas interposition between these structures and the probe. The aerogram is how we called all these gas in the GI tract. The artifacts generated were called G-lines, with the same features as A, B, and Z-lines, hence the labels GA, GB, and GZ-lines for making zero confusion with lung artifacts. GB-lines are like B-lines, apart from the fact that they do not arise from the pleural line. No rib at the abdomen, there is no bat sign here. Left: GA-lines (and GZ-lines) of a pneumoperitoneum (arrow). Right: M-mode shows the abolition of gut sliding, with a stratosphere sign (gut sliding is also abolished in surgical adherences, absence of diaphragmatic motion, peritonitis with antalgic hypopnea). GA-lines plus abolished gut sliding is labelled the Gut-A’-profile. The gut point is an equivalent of the lung point. Countless other signs can be added, such as postural changes (but we don’t like to mobilize these fragile patients). Previsible pitfall: A distended stomach will come against the anterior wall, making gut sliding hard to detect and able to generate GA lines. Consequently, analysis of gut sliding contributes more if the stomach was previously localized in one way or another
Mesenteric Ischemia/Infarction
For summarizing a very long text (read our 2010 edition), the GI tract is a vital organ, therefore in permanent dynamic. To see loops of GI tract without any motion should be a major sign alerting of something wrong in the abdomen of a patient with unusual abdominal pain or shock (Video 34.2). The data show a correlation which should be enhanced using simple, clinical elements: 87 % sensitivity, 88 % specificity when compared with patients having suspicion of ischemia [2]. Portal gas is dealt with below.
Various GI Tract Disorders
Either no part of the GI tract can be analyzed or the whole of the GI tract appears with fine details. In this unforeseeable case, the physician can see all these items: gut sliding, wall thickness (pseudomembranous colitis), wall content (bullous pneumatosis of infarction), content caliper (occlusion), echogenicity of lumen (blood, stools, etc.), massive fluid content (sequestration), gastric repletion (acute gastric dilatation), and so on.
Various Parenchymal Disorders
One can see liver or splenic abscesses (round hypoechoic heterogeneous areas), pancreatic enlargement (pancreatitis), areas of infection or infarction in various parenchymas (kidney, spleen, etc). Hepatic gas from mesenteric infarction (portal gas) yields small disseminated hyperechoic images – this was in our previous editions the only major indication of assessing the liver in critically ill patients.
Various Hollow Structure Disorders
Cholecystitis is a wide field, but in the ICU, an enlarged wall is more often a sign of acute right heart failure. We wrote a whole development in our 2010 textbook with this statement: “in a medical ICU patient, a gallbladder wall enlarged of more than 7 mm should invite to find a cause (of the trouble, pain, fever…) different from an acute acalculous cholecystitis.” Numerous data that we will never have time to submit for publication indicate that probably too many gallbladders are removed. The main issue is that the real cause (e.g., pneumonia) of the trouble (e.g., RUQ pain) is not cured.
An obstacle from urinary cavities is a basic diagnosis, especially the bladder, maybe an invitation to initiate one’s training in critical ultrasound. Anuria was extensively dealt with in our previous edition. Now, it is simply one sign of acute circulatory failure, read Chap. 30. Anuria is simply confirmed when the bladder is empty.
Vascular Disorders
An aortic aneurism enlarges the aortic lumen (what more to write?).
GI Tract Hemorrhage
Ultrasound is not mandatory for the management, but it can allow immediate diagnosis of acute deglobulization in extreme settings. We remind that the SESAME-protocol (cardiac arrest) has placed the abdomen in the third position (after lungs and veins, before pericardium and heart). We describe it here: substantial amounts of fluid are detected within the belly. They are not concave outside such as peritoneal effusions, they are convex outside, meaning the fluid is within the GI tract compartment. The fluid can be black or gray, once again it does not matter (Video 34.3).
Ultrasound can see the massive fluid before it is accessible to rectal examination or gastric tube. Anecdotal but interesting applications are the detection of esophageal varices, signs of cirrhosis – a help for inserting a Blakemore tube, the detection of complications of the Blakemore tube insertion, mainly esophageal rupture (pleural effusion, pneumothorax, subcutaneous emphysema, etc.). An anecdotal cause of GI tract bleeding, the aortic aneurism leaking inside the GI tract can be detected. Ultrasound can again see cardiac anomalies, enolic disease associated. All figures of these diseases feature in our 2010 edition, in the chapters on abdomen mainly.
Free Peritoneal Blood
This is dealt with below, in the section on trauma.
Miscellaneous
Some are familiar to any ultrasound user, such as wall disorders (hematoma, abscess), retroperitoneal hematoma, mesenteric venous thrombosis (visible without Doppler in good conditions). Some thoracic disorders simulate abdominal emergencies: pneumonia, pleural effusion, pneumothorax, sometimes myocardial infarction.
Basics in Any Urgent Procedure in the Critically Ill
The possibility of visual insertion of any needle within any area was already a small revolution: vein, pleural cavity, peritoneal cavity, pericardium, mainly. We emphasize our message around a catheter devoted to all these life-threatening emergencies. The Emergency Life-Saving Insertion of a Short Central Endovenous Catheter, or ELSISSCEC-protocol, never mind, uses a remarkable device: a multipurpose 60-mm, 16 gauge catheter (Fig. 34.2). It can be inserted with little training under sterile conditions. Inserting a short (60 mm, not so short, but not 45 cm) catheter in a central vein may appear unusual; this is what we do when time is of essence. The problem of the central venous access is solved in a few seconds, avoiding spectacular alternatives such as the transosseous access (useful it is true if there is no ultrasound).
Fig. 34.2
ELSISSCEC-protocol. A universal interventional device. In the same way we use one probe for the whole body, this simple catheter has the length and the cross-section relevant for, at will, inserting central (or less central) venous lines, withdrawing pleural, pericardial, or peritoneal fluid, withdrawing pleural gas of gas tamponade in tension pneumothorax, i.e., a simple but really universal tool
In all cases, the rules of any needle insertion should be respected.
The impaired hemostasis, frequent in critically ill patients, should be a contra-indication, but ultrasound helps to avoid the main obstacles, usually vessels in the route of the needle. On the road, arteries such as the epigastric or internal mammary arteries should be avoided. Our nonvascular microconvex probe is able to see them (see if needed Fig. 5.16 of our 2010 edition)
At the end of the road, vascular masses (aneurisms), hydatid cyst, pheochromocytoma, and other nice subtleties must be suspected before any attempt. We should beware of any round, extra-parenchymatous mass, a golden rule in our approach. Aneurisms can be highly suspected even without Doppler, using some history, the notion of a thrill, the location, etc. An echoic flow, regular, pulsatile, with whirling dynamic is rare but specific to vascular masses (see Fig. 25.5 and the text in our 2010 edition). Conversely, the detection of a slow, hectic flow within the mass indicates the absence of pressurized blood (plankton sign, see Fig. 35.10). When really the physician is embarrassed, he or she can always ask for the DIAFORA approach, described in Chap. 2.
All technical details for safe pleural puncture are in Chap. 35. For the gallbladder, a transhepatic approach limits the risk of biliary leakage in the peritoneum (we don’t overburden this textbook, see if needed our 2010 edition). There are many details at any area. In the thorax, the lung line of the pleural effusion avoids confusion with an ectopic, intra-thoracic stomach. At the groin, an abscess will not be confused with an inguinal hernia.
Basics of Subclavian Venous Line Insertion
This section will be useful only for the physicians who think that the blind approaches do not work all the time, or want to take no risk for their patients. The others can do as they will. To our opinion, the ability to find any vein in a few seconds is a reason per se to have a unit in each ICU. In our 1992 edition, this section was a whole chapter: we had to explain the interest of the concept. Now, this kind of propaganda is obsolete. We all know that blind insertions of catheters are difficult in the extreme emergency [3, 4]. The image of the physician so near to the patient and so “useless” is even ironic.
The interest of the venous cannulation under ultrasound is a revolution in the habits (read Anecdotal Note 1). This new trend, still not shared by all, will nonetheless help in making the present textbook thinner. Countless articles have been published yet with some distance, we see the same points repeated and repeated: they use the same target (jugular internal vein), the same approach (short axis), the same probe (vascular). Therefore, the reader will find here the CEURF philosophy, once again point-by-point opposed to the usual habits (apart from the main point: using ultrasound). We could have shared our experience since 1990 in peer-review literature, but our submissions on lung ultrasound prevented this, apart from just one abstract [5].
We summarize our previous editions since 1992, keeping only technical points.
Which Patients?
If one wants to take zero risk, or zero discomfort for the patient, check all the patients. Some authors keep it after failure of blind attempt, when there is contraindication of a blind attempt, or for controlling costs [6].
How to Train Before On-Site Use
One can acquire the skill first on inert material. Our method for simulating parenchymas for cheap is described in the caption of Fig. 34.3. There is no difficulty. Any person able to write, for instance, the simple letter “O” recruits without thinking agonists and antagonist muscles in an admirable synchronism.
Fig. 34.3
A phantom for cheap. Using a simple piece of tofu, for 1 $, one can observe: Left, the appearance of a metallic wire (note the acoustic shadow between arrows). Middle, a needle (arrow) aiming at a target created by a simple match; note a beautiful V-line (arrows), read p. 363. Right, the outlook of a nasogastric or chest tube (it easily penetrates the tofu parenchyma), with its large acoustic shadow (arrows). Note: these images, easy to produce in vitro, are reproduced the same in clinical conditions. The black arrows indicate the bottom of the tofu piece, roughly 4 cm thick. Tofu can be conserved far more than 1 month for such use
Which Machine?
We tried recently with a modern laptop machine, failed in locating the needle and were a bit intrigued before realizing that the lag created by the non-instant response filters is not suitable for an instant control of our movements. We use our 1992 unit.
How to Do on Site
Our approach was self-taught: in 1989, there was no teaching center to tell us what and how to do. Based on simplicity, the CEURF approach is summarized in Fig. 34.4. We fail to understand why linear probes (called vascular), why the short-axis and why the jugular vein, not to speak of human cadaver workshops are used so often. Our approach makes the field much simpler. Since 1989 with the ADR-4000, since 1992 with the Hitachi-405, we are accustomed to cannulate the subclavian vein (below the clavicula) this simple way [5]. Our published results are featured in Technical Note 1.
Fig. 34.4
Subclavian venous cannulation. This simple figure provides nine pieces of information. The right hand holds a microconvex probe, ideal for this nonlinear area (subclavian vein). Note the available space due to the probe’s small footprint. The probe is applied quietly, with minimal pressure, by a hand lying on the thorax. The probe is applied tangential to the thorax (90°): just above the region of interest. The probe exposes the vein on a long-axis view. The left hand holds the needle, quietly, with no crispation since the vacuum of the syringe is not required here. The needle is applied 45° on the thorax. Roughly 2 cm separate the needle from the probe head extremity. The needle quietly aims at the landmark of the probe (note this intelligent landmark, easy to locate). There is no sophisticated device attaching the needle to the probe. For simplifying the image in this fictitious procedure, no syringe, no sterile equipment
From the 10 points which CEURF highlighted in the Chap. 18, we briefly remind those pertaining to venous cannulation: one probe for the whole body. Not a vascular probe. A 5 MHz microconvex probe, perfect for this use. No Doppler. A long-axis approach. A particular emphasis for the (infraclavicular) subclavian vein. This venous area is the best choice in terms of infectious issues [7]. We will therefore deal only with this vein, neglecting the femoral and jugular internal ones, supposed mastered by the community.
First point, the patient, needle, probe, and screen must be roughly in a same visual site for minimizing basic difficulties, such as moving one’s head all the time. We take our single microconvex probe, insert it in a sterile sheath we use since 1992 (see the whole procedure if needed in Fig. 26.1 of our 2010 edition). Note that the microconvex probe has a size making it glide into a sheat more easily than a large vascular one. We search for the vein in a longitudinal scan below the clavicle, immediately detect its short axis and the satellite artery. We check for its patency by gently compressing it, using if needed our free hand above the clavicle, the “Doppler hand” described in Chap. 18 (Fig. 34.5).
Fig. 34.5
The Excluded Patients of the BLUE-Protocol: Who Are They? Did Their Exclusion Limit Its Value?
The BLUE-Protocol and the Diagnosis of Pneumonia
Glossary
The Ultrasound Approach of an Acute Respiratory Failure: The BLUE-Protocol
The BLUE-Points: Three Points Allowing Standardization of a BLUE-Protocol
Which Equipment for the BLUE-Protocol 2. The Probe
Subclavian compression maneuver. The left image shows how the subclavian couple immediately appears on a longitudinal scan of the thorax below the clavicula. The right image shows the complete collapsus of this vein when pressure is exerted by a probe (arrowhead). Cross-sectional scan of the subclavian vein (V), with the satellite artery (A). Image taken in 1989 using 1982’s ADR-4000 at the bedside
Related posts:
The Excluded Patients of the BLUE-Protocol: Who Are They? Did Their Exclusion Limit Its Value?
The BLUE-Protocol and the Diagnosis of Pneumonia
Glossary
The Ultrasound Approach of an Acute Respiratory Failure: The BLUE-Protocol
The BLUE-Points: Three Points Allowing Standardization of a BLUE-Protocol
Which Equipment for the BLUE-Protocol 2. The Probe
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