see also: [[Aortic dissection]], [[Traumatic arrest]] #cardiology #procedures see: [Robert Hedges - pericardiocentesis](x-devonthink-item://31ACDC98-D2CC-48C5-BE69-E9B37E53FA8C?page=383) [Dunn - pericardial tamponade](x-devonthink-item://A11D367F-12AC-46AF-9B73-5EA0C61C14AC) [Hayes' sonography of cardiac tamponade and pericardiocentesis](x-devonthink-item://E30F1B40-6A06-440D-AFF9-1E93351D0F29) [emDOCs – When Does an Effusion Become Pericardial Tamponade?](cubox://card?id=6826101066212311567) > note that the commonest symptom of early tamponade is *dyspnoea* which unfortunately is also the commonest symptom of PE (and pulm HTN, among other things). In an ambiguous clinical context, further supports the value of POCUS as an early differentiating test. # POCUS findings #pocus - RV early diastolic collapse - RA systolic collapse  - RA systolic collapse cuz this is when pressure lowest - This is what causes the "see-saw" appearance - LA will also have systolic collapse - swinging of LV apex - dilated IVC with <50% inspiratory collapse → suggests [[Right Ventricle POCUS#RVSP|right atrial pressure]] is > 20 - often hyperdynamic and small LV due to ↓ venous return - "diastolic flow reversal in hepatic veins" (who is really looking here in a hypotensive pt with pericardial effusion?? I guess someone needs to count the angels at the tip of the pen...) ## example images ![[Pasted image 20241107221617.png|A4C with RA collapse in systole. we know it is systole because MV and TV are closed!]] ![[Pasted image 20241107221724.png|subcostal view showing RV collapse]] ![[Pasted image 20241107221831.png]] - M-mode trace of subcostal IVC diameter and changes with inspiration. - There is a *plethoric IVC* (>2.1cm; 2.32 in diameter here) - Minimal (<50%) collapsing with respiratory variation on inspiration - Consistent with cardiac tamponade as the right atrial filling is impaired and blood backs up into IVC # common causes **Acute causes:** - [[Aortic dissection]] type A - post cardiac surgery -- usually valvular surgery - cardiac rupture (presents as PEA) ; usually rapidly fatal. eg AMI with free wall rupture - penetrating chest trauma The following would not be acute, but *gradual onset non-traumatic* tamponade from any cause of [[Pericarditis]], eg: - malignant eg lymphoma - dressler's syndrome  - uraemia - coagulopathy *note that effusions have broader differential:* ![[Pasted image 20240820231051.png]] # Treatment ![[Pasted image 20240930152005.png]] ## pericardiocentesis **indications** - shock / haemodynamic instability - arrest / PEA from tamponade - determine cause of of effusion **contraindications** - no *absolute* contraindications if the patient has arrested - relative: - coagulopathy - prosthetic heart valve - PPM and cardiac device - lack of direct visualisation during procedure - traumatic pericardium [[Resuscitative Thoracotomy]] preferred **complications** - dysrhythmia - air embolism - haemothorax - pneumothorax - pneumopericardium - coronary artery injury (puncture or laceration) - [[Procedures#procedures and specific anatomical considerations|internal mammary artery injury]] - intercostal vessel or nerve injury - atrial or ventricle puncture (myocardial perforation) - suppurative pericarditis - *acute pulmonary oedema* (due to rapid drainage of pericardial fluid leading to excessive LV pre-load!) - acute ventricular dilation > Aspiration of blood during pericardiocentesis raises concern of cardiac puncture. > - Blood retrieved from the ventricle usually clots faster than bloody fluid aspirated from the pericardium. > - However, if the bleeding is brisk enough, blood may still clot and does not necessarily point toward ventricular puncture. > - The hematocrit of pericardial fluid should always be *lower* than that of a sample from the systemic vascular system, except in patients with aortic dissection or acute myocardial rupture. > - can also injected *agitated saline* through needle; assess pericardium and ventricles for presence of microbubbles vs pericardium **Techniques** - *Apical* - safest. risk of pneumothorax, intercostal vessel damage, Lv puncuure - *parasternal* - high risk of cardiac or vessel injury. risk of RA puncture or RV puncture, internal mammary artery damage (located 1-3cm lateral to sternal border), internal thoracic, proximal coronary artery, intercostal artery damage - *subxiphoid* - highest risk of failure due to long needle tract. liver injury, right atrial / ventricular puncture . **Equipment** - can use cannula from central line kit or 18-22g spinal needle - full cardiac monitoring > [!info] **General procedure steps** > 1. identify appropriate site, with largest size of effusion present > 2. prep skin and anaesthetise area > 3. advance needle under uss guidance aspirating for fluid > 4. when fluid aspirated, insert guidewire and confirm guidewire position with ultrasound > 5. dilate tract and insert pigtail catheter over guidewire > 6. remove guidewire > 7. suture drain in place, attach drain bag, apply sterile dressings ### Subxiphoid approach see [Robert hedges subxiphoid](x-devonthink-item://31ACDC98-D2CC-48C5-BE69-E9B37E53FA8C?page=402) ![[Pasted image 20240930151730.png]] - introduce the needle 1 cm inferior to the left xiphocostal angle at a 15 to 30-degree angle to the skin. - Because the heart is an anterior structure, angles greater than 45 degrees may lacerate the liver or stomach. - Aim toward the left shoulder and advance the needle slowly while continuously maintaining negative pressure on the syringe to aspirate any fluid. - Aspirate with an “in-and- out” vector only, not “side-to-side,” which may lacerate tissue. - If no fluid is aspirated, withdraw the needle completely and redirect it in a deeper posterior trajectory. - If no fluid is aspirated after redirecting the needle, withdraw the needle and redirect it, working from the patient’s left to right, until it is aimed at the right shoulder. - Recommendations regarding needle trajectory vary widely, including toward the right shoulder, sternal notch, and left shoulder ### Parasternal approach ![[Pasted image 20240930151807.png]] - can often use linear probe - needle at 45 deg angle to skin in plane of USS probe - identify [[Procedures#procedures and specific anatomical considerations|internal mammary]] artery/internal thoracic artery (can use doppler) ; see picture of USS below - continued aspiration as needle approaches RV - once pericardial fluid/blood aspirated, slide cannula into pericardial space, attach 3-way tap ![[Pasted image 20241102190432.png]] ![[Pasted image 20241102190358.png]] ![[Pasted image 20241102190413.png]] ## other therapy - resp therapy - maximise oxygenation - PEEP may further decrease cardiac output - ionotropic support - unlikely to be effective; temporising - *dobutamine* is agent of choice ; reduces systemic vascular resistance which may be of benefit - *avoid* vasopressors (metaraminol, norad), although may help short term (Robert hedges says helped in animal models, not humans). - IV fluid challenge - temporising at best - improves haemodynamics in 50% of patients - worsens them in 35%! CPR does not do much in the presence of tamponade # OSCE questions - [RMH 2020.2 - SCBD tamponade](x-devonthink-item://DA010B18-29A6-4B04-BE3C-A8862B421967)