Questioning the Role of Carotid Artery Ultrasound in Assessing Fluid Responsiveness in Critical Illness: A Systematic Review and Meta-Analysis
Table 3
(a) GRADE evidence profile for ∆CDPV. (b) GRADE evidence profile for CBF.
Outcome
№ of studies (no of patients)
Study design
Factors that may decrease certainty of evidence
Effect per 1,000 patients tested
Test accuracy CoE
Risk of bias
Indirectness
Inconsistency
Imprecision
Publication bias
Pretest probability of 10%
Pretest probability of 20%
Pretest probability of 50%
(a) Question: should ∆CDPV be used to diagnose fluid responsiveness in critically unwell patients?
True positives (patients with fluid responsiveness)
7 studies 297 patients
Cross-sectional (cohort type accuracy study)
Seriousa
Seriousb
Not serious
Not serious
None
72 (63–80)
144 (126–160)
360 (315–400)
⊕⊕○○ low
False negatives (patients incorrectly classified as not having fluid responsiveness)
28 (20–37)
56 (40–74)
140 (100–185)
True negatives (patients without fluid responsiveness)
7 studies 297 patients
Cross-sectional (cohort type accuracy study)
Seriousa
Seriousc
Not serious
Not serious
None
783 (657–846)
696 (584–752)
435 (365–470)
⊕⊕○○ low
False positives (patients incorrectly classified as having fluid responsiveness)
117 (54–243)
104 (48–216)
65 (30–135)
Sensitivity
0.72 (95% CI: 0.63–0.80)
Specificity
0.87 (95% CI: 0.73–0.94)
Prevalences
10%
20%
50%
(b) Question: should CBF be used to diagnose fluid responsiveness in critically unwell patients?
True positives (patients with fluid responsiveness)
5 studies 173 patients
Cross- sectional (cohort type accuracy study)
Serious
Serious
Not serious
Not serious
None
70 (56–80)
140 (112–160)
350 (280–400)
⊕⊕○○ low
False negatives (patients incorrectly classified as not having fluid responsiveness)
30 (20–44)
60 (40–88)
150 (100–220)
True negatives (patients without fluid responsiveness)
5 studies 173 patients
Cross- sectional (cohort type accuracy study)
Serious
Serious
Not serious
Not serious
None
720 (450–846)
640 (400–752)
400 (250–470)
⊕⊕○○ low
False positives (patients incorrectly classified as having fluid responsiveness)
180 (54–450)
160 (48–400)
100 (30–250)
Sensitivity
0.70 (95% CI: 0.56–0.80)
Specificity
0.80 (95% CI: 0.50–0.94)
Prevalences
10%
20%
50%
Explanations: aseveral studies failed to identify the independence of the index test and reference standard, i.e., blinding. bThe recruitment methodology was not specified in several studies. Some studies failed to exclude patients with conditions (aortic stenosis) where carotid US may be unreliable. cSome studies excluded patients with heart failure and other comorbidities, which are common in critically unwell. This may impact its generalisability.
