From the Guidelines
The anesthetic goal in mitral stenosis is to maintain a slow heart rate, adequate preload, systemic vascular resistance, and sinus rhythm while avoiding tachycardia, hypovolemia, and pulmonary hypertension. To achieve this, aim for heart rates between 60-80 beats per minute using beta blockers like metoprolol 5-10mg IV or esmolol infusion as needed 1. Maintain adequate preload with judicious fluid administration, targeting a slightly elevated central venous pressure, and preserve systemic vascular resistance with vasopressors such as phenylephrine 50-100 mcg boluses or norepinephrine infusion if needed 1. Avoid factors that increase pulmonary vascular resistance including hypoxemia, hypercarbia, and acidosis by ensuring adequate ventilation with tidal volumes of 6-8 ml/kg and normocapnia. Use opioid-based anesthesia (fentanyl 10-15 mcg/kg or equivalent) to blunt sympathetic response. Consider transesophageal echocardiography for monitoring cardiac function. These goals are critical because mitral stenosis creates a fixed cardiac output state where the narrowed valve prevents adequate left ventricular filling, making patients highly dependent on diastolic filling time (requiring slower heart rates) and preload to maintain cardiac output 1. Some key points to consider in the anesthetic management of patients with mitral stenosis include:
- Maintaining sinus rhythm to ensure adequate diastolic filling time
- Avoiding tachycardia, which can reduce diastolic filling time and increase left atrial pressure
- Optimizing loading conditions to maintain adequate forward cardiac output without excessive rises in left atrial pressure and pulmonary capillary wedge pressure
- Using invasive hemodynamic monitoring to optimize loading conditions in asymptomatic patients with moderate or greater degrees of rheumatic MS with a pulmonary artery systolic pressure <50 mm Hg 1. Overall, the anesthetic goal in mitral stenosis is to maintain a stable hemodynamic state, avoiding factors that can precipitate acute decompensation, and ensuring optimal perioperative care to minimize morbidity and mortality.
From the Research
Anaesthetic Goals in Mitral Stenosis
The primary anaesthetic goal in mitral stenosis is to maintain haemodynamic stability and prevent complications. Key considerations include:
- Maintaining a normal sinus rhythm to prevent atrial fibrillation, which can worsen the condition 2
- Avoiding increases in heart rate, which can reduce diastolic filling time and worsen stenosis 3
- Maintaining adequate preload to ensure sufficient cardiac output, while avoiding excessive fluid overload, which can lead to pulmonary oedema 4, 2
- Minimizing the impact of anaesthesia on haemodynamic parameters, as anaesthesia can affect the assessment of mitral stenosis severity 5
Haemodynamic Management
Haemodynamic management is critical in patients with mitral stenosis. This includes:
- Using invasive monitoring, such as pulmonary artery catheters, to guide fluid management and vasoactive medication selection 4, 2
- Utilizing transesophageal echocardiography (TEE) to assess cardiac function and guide haemodynamic management 2
- Avoiding excessive increases in afterload, which can worsen the condition 3
Anaesthetic Techniques
The choice of anaesthetic technique can impact haemodynamic stability in patients with mitral stenosis. Considerations include: