EDU cardiaque (sous-xyphoïdienne) Flashcards
Quelle sonde prendre?
curvilinéaire
Préparation des paramètres de la machine? (profondeur, gain, system preset)
Dive the depth to centre relevant anatomy.
Recommended starting depth for beginners: 30 cm or machine maximum in adults. Initial depth for pediatric patients varies with age.
Beginners should always set the initial depth deep enough to avoid missing relevant anatomy. With experience, initial depth should be adjusted to account for patient body habitus.
Gain = mid-range.
System preset(s) = cardiac / abdominal.
Position du pt ? ‘‘draping’’?
décubitus dorsal
Towel / sheet covering patient with abdomen exposed from umbilicus to xiphoid process.
Orientation et prise de la sonde?
Probe orientation
Probe flat and parallel to the floor / stretcher with the beam directed towards the patient’s head and the probe marker oriented towards patient right.
Probe grip
Keep probe flat, two or three fingers on top, with the remainder of the fingers on the side of the probe.
Repère externe de départ?
Midline just cephalad to the umbilicus.
Repère interne?
Foie
Zone d’intérêt? (2)
Inner walls of the left ventricle at the mid-ventricular level (i.e. just beyond the mitral valve leaflets) to assess for gross estimation of cardiac activity.
Entire inferior pericardium to intersection with interventricular septum for the detection of a pericardial effusion (PCE)
Décrire la technique complète?
Starting just cephalad to the umbilicus, keeping the probe in the midline and flat, CPoCUS-IPs must slide the probe slowly cephalad, aiming at the patient’s head, with the goal of achieving good contact between the probe, skin, and liver.
Using the liver as both the internal landmark and an acoustic window, IPs must attempt to visualize the entire heart to assess for cardiac activity. At a minimum, the left ventricular inner walls at the mid-point of the ventricle (i.e. just beyond the mitral valve leaflets) must be visible. This location is then utilized to estimate cardiac activity, categorizing it as either absent, poor, good or indeterminate (see below for specifics of each category).
Assessment for a pericardial effusion is then attempted by visualizing the entire inferior pericardium to the intersection with the interventricular septum. The pericardium should be swept first anteriorly and then posteriorly, maintaining continuous contact with the liver, using the disappearance of the heart in both directions as the end-points of sweeping. During this part of the sub-xiphoid cardiac scan, the pericardium may be magnified, as needed, by decreasing the depth.
Trucs pour améliorer la qualité et obtenir image concluante (4)
- Ensure constant firm contact between probe and liver. This maneuver often involves pushing firmly.
- Bend patient’s knees/flex hips. This maneuver will relax the abdominal muscles and allow better liver contact.
- Slide the probe to the patient’s right and heel medially. Only useful if the left hepatic lobe is small or absent.
- Ask the patient to take a deep breath and hold it. Once the patient has held their breath, the operator should immediately push the probe back in to ensure good liver contact AND sweep the probe slightly posteriorly. This secondary movement of the probe is often needed to reacquire a good image of the heart, as the expansion of the lungs will often push the probe away from the sub-xiphoid area while simultaneously moving the heart posteriorly. Once the heart is clearly seen, the operator should perform a complete sweep while the patient holds their breath. This maneuver is ideally performed after a reasonable liver window has already been achieved.
Piège d’interprétation? (4)
Mistaking epicardial fat pad for a PCE.
Deeming a scan to be determinate when the entire inferior pericardium is not seen.
Attempting to assess cardiac activity using an inadequate view (i.e. not enough of the LV inner walls seen).
Missing a very large pericardial effusion by not having the liver on the screen as the internal landmark. The liver allows the operator to localize both the visceral pericardium (i.e. inner layer, contacting the right ventricular free wall in this area, inferior to the heart) and the parietal pericardium (i.e. outer layer, aka central tendon of the diaphragm in this area). With a very large PCE, the parietal pericardium might be a considerable distance away from the heart. By ensuring that the liver is always on the screen, the parietal pericardium will be visible even in these circumstances
Pièges dans la techinque? (9)
Sweeping too quickly.
Poor probe grip (i.e. fingers under probe, fingers over the end of the probe, probe marker oriented towards patient left).
Inadequate contact between the probe, skin and liver.
Releasing pressure while sweeping, especially anteriorly.
Sliding up with probe tipped up (i.e. probe not flat). This might be due to either inadvertently keeping the probe tipped up and/or having an ineffective probe grip (i.e. fingers, thumb or cable beneath the probe).
Starting scan immediately at the xiphoid process.
Allowing probe to drift towards patient’s left resulting in image degradation from stomach gas.
Not completely sweeping through the heart until it disappears in either direction.
Sweeping too far (i.e. past the point where the heart disappears).
Pièges d’interprétation clinique? (4)
Assuming that a small pericardial effusion is clinically insignificant. Depending on how rapidly the fluid accumulated, a small effusion may cause hemodynamic compromise. A PoCUS finding is just one data point and should always be taken within the context of the overall clinical picture of each patient.
Assuming that a large pericardial effusion means cardiac tamponade. While it is true that the larger the effusion, the more likely the patient will be in tamponade, this diagnosis is always a clinical one. If the fluid accumulated slowly, a large effusion may be tolerated by the patient.
Ceasing resuscitative efforts based solely on PoCUS findings. Cardiac standstill is indeed an ominous finding, but discontinuation of resuscitative efforts should always be based on the overall impression of the treating clinician, taking all factors into context including ‘downtime’, patient’s age, comorbidities, electrical activity of the heart, and mitigating factors such as drug overdose, etc.
PoCUS use causing prolonged CPR pauses in cardiac arrest. Sub-xiphoid cardiac PoCUS can be utilized during cardiac arrest provided that:
- It is performed for the shortest duration possible to minimize CPR interruption. This interval must be less than five seconds.
- The clinician performing PoCUS must prepare for the scan BEFORE CPR is paused.
Additional CORE PoCUS indications other than sub-xiphoid cardiac may be performed at the discretion of the treating clinician provided that these scans are completed WHILE CPR is on-going. Only cardiac PoCUS can be used at pulse checks.
Comment décrire l’activité cardiaque?
Cardiac activity is estimated using the ‘eyeball’ method of measuring LV fractional shortening.
The inner walls of the mid left ventricle (LV) level (just beyond the mitral valve leaflets) must be seen to comment on cardiac activity.
Definition of fractional shortening: Decrease in the distance between the LV inner walls during systole (when the mitral valve is closed).
Cardiac activity can be categorized as follows:
Good: 30% or greater fractional shortening.
Poor: Much less than 30% LV fractional shortening. By the ‘eyeball’ method, this is a ventricle that is obviously not squeezing well.
Absent: No movement of the LV inner walls towards each other and no movement of the mitral valve leaflets.
Indeterminate: Unable to adequately visualize the LV inner walls at the mid-LV level.
Quelles sont les conclusions possibles?
images concluantes ou non concluantes
ÉPC +, ÉPC -
contractilité: bonne, moyenne, mauvaise, absente ou indéterminée
Qu’est-ce que le Lucky 7?
Zone d’intérêt: péricard ad jonction de l’apex qui se marque par le septum cardiaque
