How to manage postoperative hypotension in a patient with heart failure?

From the Guidelines

Post-operative hypotension in heart failure patients should be treated with a cautious approach, starting with a passive leg raise (PLR) test to assess fluid responsiveness, as evidenced by a recent study 1.

Treatment Approach

The management of post-operative hypotension in heart failure patients requires careful consideration of their underlying cardiac dysfunction.

• First-line treatment typically involves assessing the patient's volume status and using a PLR test to determine if they are fluid responsive, as supported by a study published in the British Journal of Anaesthesia 1.
• If the PLR test is positive, indicating fluid responsiveness, a judicious intravenous fluid administration (250-500 mL crystalloid bolus) may be appropriate, but this must be done cautiously in heart failure patients to avoid volume overload.
• If hypotension persists after fluid resuscitation, inotropic agents are preferred over vasopressors, with dobutamine (starting at 2-5 mcg/kg/min) often being the first choice, as it improves cardiac contractility and output without significantly increasing afterload, as suggested by a study in Critical Care 1.
• For patients with severe hypotension, norepinephrine (0.01-0.3 mcg/kg/min) may be necessary as it provides both inotropic and vasopressor effects.
• Milrinone (0.375-0.75 mcg/kg/min) is useful in patients with beta-blocker therapy as it works through a different mechanism.

Monitoring and Titration

Throughout treatment, continuous hemodynamic monitoring is essential, including:

• Blood pressure
• Heart rate
• Urine output
• Potentially central venous pressure or cardiac output measurements The underlying cause of hypotension should be addressed simultaneously, whether it's hypovolemia, cardiac dysfunction, or medication effects. Treatment should be titrated based on the patient's response, with the goal of maintaining adequate organ perfusion while avoiding excessive cardiac workload that could worsen heart failure, as highlighted in a study published in 2019 1.

From the FDA Drug Label

Blood volume depletion should always be corrected as fully as possible before any vasopressor is administered. When, as an emergency measure, intraaortic pressures must be maintained to prevent cerebral or coronary artery ischemia, LEVOPHED can be administered before and concurrently with blood volume replacement Add the content of the vial (4 mg/4 mL) of LEVOPHED to 1,000 mL of a 5 percent dextrose containing solution. Each mL of this dilution contains 4 mcg of the base of LEVOPHED Give this solution by intravenous infusion. Insert a plastic intravenous catheter through a suitable bore needle well advanced centrally into the vein and securely fixed with adhesive tape, avoiding, if possible, a catheter tie-in technique as this promotes stasis An IV drip chamber or other suitable metering device is essential to permit an accurate estimation of the rate of flow in drops per minute After observing the response to an initial dose of 2 mL to 3 mL (from 8 mcg to 12 mcg of base) per minute, adjust the rate of flow to establish and maintain a low normal blood pressure (usually 80 mm Hg to 100 mm Hg systolic) sufficient to maintain the circulation to vital organs In previously hypertensive patients, it is recommended that the blood pressure should be raised no higher than 40 mm Hg below the preexisting systolic pressure. The average maintenance dose ranges from 0. 5 mL to 1 mL per minute (from 2 mcg to 4 mcg of base).

To treat post-op hypotension in a heart failure patient, blood volume depletion should be corrected before administering any vasopressor.

• Norepinephrine (IV) can be used to maintain blood pressure, with an initial dose of 2-3 mL/min (8-12 mcg base/min) and adjusted to maintain a low normal blood pressure (80-100 mmHg systolic).
• The average maintenance dose is 0.5-1 mL/min (2-4 mcg base/min) 2, 2.
• Central venous pressure monitoring is usually helpful in detecting and treating this situation 2, 2.
• Duration of therapy should be continued until adequate blood pressure and tissue perfusion are maintained without therapy, and infusions should be reduced gradually, avoiding abrupt withdrawal 2, 2.

From the Research

Treatment of Post-Op Hypotension in Heart Failure Patients

• The treatment of post-op hypotension in heart failure patients involves fluid resuscitation, with the choice of fluid being a crucial decision 3, 4, 5, 6.
• Colloids and crystalloids are the two main types of fluids used in fluid resuscitation, with no clear evidence of one being superior to the other in terms of reducing mortality 3, 5.
• Crystalloids, such as normal saline or balanced salt solutions, are often preferred due to their lower cost and similar effectiveness compared to colloids 3, 5, 6.
• However, the use of hydroxyethyl starch, a type of colloid, has been associated with increased acute kidney injury and use of renal replacement therapy 5.
• In heart failure patients, orthostatic hypotension is a common comorbidity, and its management is crucial to prevent further complications 7.
• Non-pharmacologic interventions, such as increasing fluid intake and using compression stockings, are often recommended for managing orthostatic hypotension in heart failure patients, as pharmacologic treatments may have adverse effects 7.

Fluid Resuscitation Strategies

• Goal-directed fluid resuscitation, where fluids are administered based on individual patient needs and physiologic parameters, is recommended 5.
• The use of balanced crystalloid solutions, such as Ringer's lactate, may be preferable to normal saline due to their reduced risk of hyperchloremic acidosis and impaired renal function 6.
• Fluid resuscitation should be initiated early, and the choice of fluid should be based on the individual patient's needs and underlying conditions 4, 6.

Considerations in Heart Failure Patients

• Heart failure patients with orthostatic hypotension require careful management to prevent further complications, such as syncope and falls 7.
• The prevalence of orthostatic hypotension in heart failure patients ranges from 8% to 83%, depending on the population and setting 7.
• Dizziness and palpitations are common symptoms of orthostatic hypotension in heart failure patients, and their management should be tailored to the individual patient's needs 7.