Dr Bernadoni Right Heart Failure

PULMONARY HTN +  RV SPIRAL OF DEATH-

Definition is mean pulmonary artery pressure >20mmHg (on R heart cath). This can be estimated based on PA pressure >35 on echo

• In patients with acute PE or with chronic pHTN and an acute VQ mismatch (eg pneumonia)

• This is translated as an increased afterload on the RV, which does not tolerate this well. Pt becomes hypotensive, shocky.

• Of note the LV will appear underfilled and hypokinetic on XR- this does not represent hypovolemia and the heart will not respond well to fluid administration.

• RV vs LV perfusion- LV gets perfused only during diastole, whereas under normal circumstances the RV gets perfusion throughout the cardiac cycle. When pHTN is present (and right heart pressures are subsequently high) the transmural pressure across the RV only allows perfusion during diastole, causing ischemia and reduced contractility. It can also leads to relative or bradycardia through hypoperfusion of the SA/AV node

This group of events is known as the RV spiral of death.

HOW TO AVOID IT-

Fluids-

These pts are rarely volume responsive in a good way. Fluid administration pushes them further into above spiral

(In the setting of PE or chronic RHF/pHTN) when patients have evidence of R heart failure on echo (dilated RV, Mcconell’s sign, low TAPSE) they will not respond well to further fluid administration.

If their RV looks small/empty too, may consider a very small fluid bolus and evaluate for effect.

Most patients will benefit from diuresis, even when they are hypotensive and have LV underfilling (diuresis improves RV function and allows the pt to better fill their LV and increase their CO

PRESSORS

Instead, aggressively support MAP with pressors-

Aim is to raised MAP without raising pulmonary blood pressure

• Norepinephrine is go to- increases contractility, gives peripheral vasoconstriction and at low doses should increased pulmonary vascular constriction much
• Vaso is next line- gives peripheral vasoconstriction but actually reduces pulmonary pressures- this is exactly what is wanted
• Can consider dobutamine as third line- start at 5mcg/kg/min

AIRWAY MANAGEMENT (+INHALED MEDS)

• Intubation should be avoided if at all possible.
• Consider use of nitric oxide prior to intubation (via BIPAP/HFNC)- see below
• Paralysis causes hypoxia and hypercarbia- leading to hypoxic vasoconstriction and worsened pulm HTN and RV afterload
• PPV increases RV afterload and reduces output

SO:

• Have push dose pressors ready and strongly consider placing an arterial line prior to intubation
• Have atropine at bedside
• Use etomidate for sedative (ketamine may increase pulmonary vascular resistance)
• Do not use straight RSI- continue ventilation (bagging or BIPAP)
• Can break from ARDS net protocols and consider high FiO2 without raising PEEP as much as normal. Keep plateau AND PEAK pressures low

If pt remains hypotensive/hypoxic use inhaled nitric oxide- start at 40ppm

Or consider inhaled epoprostenol

In the absence of the above nebulize 5mg of nitroglycerin

SYSTEMIC VASODILATORS

Many chronic pHTN pts have continuous vasodilator pumps running

If pt has pump failure/otherwise their systemic meds are stopped restart them at the same dose immediately. They can be given peripherally if necessary

MASSIVE PE

SBP <90 for 15mins (submassive PE is with RV strain based on trop, BNP, echo etc)

• Thrombolysis if bleeding risk is acceptable (this is a case by case decision taking into account a large number of factors). Note that is unclear how much thrombolysis actually causes bleeding in acute PE (studies show similar rates of bleeding with heparin alone cf heparin and tpa)
• In patients with a pulse typical is 100mg IV tPA over 2h. Can give 10mg as a push and the other 90 as an infusion over the 2 hours
• In cardiac arrest 50mg IV push
• Note above doses have minimal evidence base.
• Run heparin concurrently

INTERVENTIONAL THERAPY + ECMO

Catheter directed therapy recommended in patients with high bleeding risk, tPA contraindicated. This should initially be percutaneous embolectomy, can use catheter directed thrombolysis (tPA) if unsuccessful.

ECMO- Extra-corporeal membrane oxygenation

In PE ECMO is run Venousà Arterial (VA ECMO).

This allows circulation to bypass the heart and lungs, bypassing the failing right heart and the elevated pulmonary pressures. Helpful with the R heart failure of PE (or the reduced CO in STEMI, myocarditis, low+slow poisoning etc)

In patients with pure lung pathology (ARDS, asthma, pulmonary contusion) it can be run Venous-Venous (VàV), which bypasses the lungs but still requires good cardiac function

Consider ECMO if non ECMO mortality is >50%, even more so if >80% (and has ECMO responsive pathology)

Reserve for pts likely to have benefit (reversable cause of current illness, no major life limiting comorbidities or advanced age) and less likely to have harm (pts require heavy anticoagulation so those with high bleeding risk are likely to be harmed)

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Josh Senn- GU abx

• Don’t treat asymptomatic bacteria (>10⁵ CFU) without symptoms unless pregnant or a guy pending a urological procedure

• Use nitro 100 bid (if CrCl >30) or cephalexin qid for 5 days for uncomplicated UTI in a male or female

• Chlamydia- use 1g azithromycin PO one time. Use doxy 100mg BID for 7 days if PID. Second line levofloxacin, erythromycin, ofloxacin.

• Gonorrhea- Ceftriaxone 250mg IM x1 (+azithro or doxy). Alternatives are cefixime or gentamicin + azithro

• Trichomoniasis- metronidazole 500mg PO BID x7 days has higher cure rate than 2g one time. Topical gel does not have good cure rate. Alternative is tinidazole

• BV- 500mg BID x 7 days, can use vaginal gel BID x 7 days. Alternatives are clinda or tinidazole

• Benzathine penicillin 2M units for primary or early latent. More complex with neurosyphilis