Anesthesia Management for Asymptomatic Aortic Narrowing

  

    

    
No abnormality
    
Mild stenosis or sclerosis
    
Moderate stenosis
    
Severe stenosis
    
Other lesion
  
  

    
Murmur heard (n=96)
    
30(31%)
    
35(36%)
    
16(17%)
    
7(7%)
    
8(8%)
  
  

    
No Murmur heard (n=278%)
    
175(63%)
    
78(28%)
    
8(3%)
    
1(0.5%)
    
16(6%)
  

Table 1: Presence of a murmur detected by auscultation in relationship to severity of aortic stenosis by echocardiography in hip fracture patients. Values are number (proportion) [9].

After draping by the surgeon, 15 minutes following the spinal anesthesia, the patient presents hemodynamic instability with unmeasurable blood pressure and altered consciousness. This necessitates the placement of a central venous catheter for administration of vasoactive drugs, such as norepinephrine, and conversion to general anesthesia with invasive blood pressure monitoring. The surgical procedure is minimized, and the patient is transferred to the postoperative intensive care unit. After meeting the necessary prerequisites, the patient is extubated with a low dose of vasoactive medication, without any deficits or sequelae.

A postoperative cardiac evaluation with an echocardiogram reveals severe mitral stenosis with an effective valve area of 0.6 cm2, necessitating cardiovascular management. The patient is transferred to the cardiology service for further care.

Discussion

The role of the anesthetist is major in the risk assessment the RA is suspected before the discovery of an unknown breath and the first step will be to confirm (or invalidate) the diagnosis with an essential TTE, the second step of reasoning then being identical to the first case of fig. We must remember the high prevalence of RAC in the octogenarian (>10%) to underline the importance auscultation during the anesthesia consultation, as long as the ACR remains long asymptomatic. The elements to be gathered are: the abolition of B2, the search (sometimes difficult) for stress symptoms, ultrasound criteria severity of ACR, the existence of associated significant mitral insufficiency, marked systolic LV dysfunction (EF <40%). Finally in cases where the stress assessment is impossible or negative, the stress ultrasound may be indicated [7].

The main anaesthetic concern aroused by an undiagnosed heart murmur is the possibility of severe aortic stenosis. This has previously been shown to be a major risk factor for morbidity [8]. Aortic stenosis is increasingly common in our ageing population and its severity increases with age. Before our report, the prevalence and severity of aortic stenosis in an unselected patient population admitted with a surgical diagnosis of hip fracture was unknown. We found that 8% of patients who underwent echocardiography had either moderate or severe stenosis. Since we investigated all patients present when the echocardiography technician was available, our data should reflect the entire population of fractured femur patients [9].

A population-based sample from Finland of 501 people reported echocardiographic findings of moderate to severe aortic valve stenosis in 8.8% of females and 3.6% of males in patients aged 75–86 years [10].

Classically, a loud (grade 4/6), late-peaking systolic murmur radiating to the carotid arteries, a single or paradoxically split second heart sound, and a delayed and diminished carotid upstroke, confirm the presence of severe aortic stenosis. However, physical examination findings are specific but not sensitive for making the diagnosis and determining its severity [11]. In previous work, it is usually only those patients who had a previously undiagnosed systolic murmur that would have undergone pre-operative echocardiography [12]. Our evaluation revealed that 87/278 (31%) of patients without clinically detected murmurs had aortic stenosis. Conversely, in the 96 patients where a murmur was heard, 30 (31%) had a normal echocardiogram. Thus, pre-operative auscultation of a murmur does not necessarily reflect either the presence or the severity of the underlying aortic valve disease. However, if a murmur is heard, then moderate or severe aortic stenosis is 8.5 times more likely [9]. At the end of this assessment, in a multidisciplinary manner, a solution must be proposed. To the patient and his family, taking care to provide information on the risks respective and proposed solutions. Many asymptomatic patients can be operated on for their non-cardiac surgery as a first step provided that the management be optimized (Figure 1) [13- 15].

    

    

    Figure 1: Non cardiac surgery and severe ACR.