|
Normal values (See Appendix 1) |
||||
| Monitoring tool |
Parameter |
Normal values |
Comments |
Patient population in which the parameter is useful |
|
|
||||
| Esophageal |
FTc, PV |
FTc: 330–360 ms |
FTc: correlates with cardiac output, and a mere change in the value in response to a fluid challenge can indicate hypovolemia [10-14] |
The hemodynamically compromised |
| Doppler monitor |
PV (age-dependent): |
PV: affected by afterload and left ventricular contractility [8] |
Especially useful in patients with contraindications to invasive procedures [17] |
|
| 20 years 90–120 cm/s; |
Mostly studied in intubated, sedated patients |
|||
| 50 years 70–100 cm/s; |
||||
| 70 years 50–80 cm/s |
||||
| Thoracic bioimpedance |
CO/CI, SV/SI, SVR/SVRI, TFC, PEP/LVET |
CO correlates well (r = 0.83) with PA catheter [21] |
Limited in diaphoretic patients Studies done in CHF, sepsis, trauma, emergency department patients CO correlates well (r = 0.83) with PA catheter [21] |
Useful in nonintubated patients – noninvasive |
| PEP/LVET reflect contractility [22-25] |
||||
| End-tidal carbon dioxide |
PetCO2 |
35–45 mmHg |
Direct correlation (r = 0.64–0.87) [81,82] with PaCO2 [37,38] |
COPD |
| CO and coronary perfusion pressure surrogate [41-44] |
Noninvasive ventilation |
|||
| >10 mmHg: Critical |
<10 mmHg indicates unlikely ROSC [45] |
Cardiac arrest |
||
| Sublingual capnography [47-49] |
SL CAP |
70 mmHg [48] |
A surrogate for gastric tonometry (i.e. a marker of tissue hypoxia) |
CO2 could be an earlier, more rapid indicator of shock than biomarkers |
| Shock: >70 mmHg; sensitivity 73%, specificity 100%, positive predictive value 100% |
ED studies lacking |
|||
| Lactic acid |
LAC |
<2.5 mmol/l |
>4.0 mmol/l [53]: 98.2% specific for hospital admission from ED; 96% specific in prediciting mortality in normotensive inpatients; 87.5% specific in predicting mortality in hypotensive inpatients [55] |
Shock of any cause |
| C-reactive protein |
CRP |
<50–60 mg/l |
Higher CRP level carries worse prognosis [65-67] |
Sepsis |
| Procalcitonin [81] |
PCT |
0–0.5 ng/ml |
>0.6 ng/ml is approximately 69.5% sensitive for infection [84] |
Infected, septic patients |
| >2.6 ng/ml: odds ratio 38.3 for septic shock [84] |
||||
| Central venous oxygen saturation [61,73,74] |
ScvO2 |
65–75% |
A surrogate for mixed venous oxygen saturation and CI |
Studies have found ScvO2 to be useful in myocardial infarction, intensive care unit, surgical, trauma, and septic/cardiogenic shock patients |
| <60% indicates global tissue hypoxia, anemia, sepsis, low CO |
||||
| >80% indicates venous hyperoxia, which implies a defect either in oxygen utilization or delivery [76] |
||||
| Arteriovenous CO2 gradient [73] |
A–V CO2 |
<5 mmHg |
Inversely proportional to CI |
Useful for identifying delivery dependent states, and therefore adequacy of tissue perfusion |
|
CHF, congestive heart failure; CI, cardiac index; CO, cardiac output; COPD, chronic obstructive pulmonary disease; CRP, C-reactive protein; ED, emergency department; FTc, corrected flow time; LVET, left ventricular ejection time; PA, pulmonary artery; PCT, procalcitonin; PEP, pre-ejection period; PetCO2, end-tidal carbon dioxide tension; PV, peak velocity; SI, stroke index; SL CAP, sublingual capnography; SV, stroke volume; ScvO2, central venous oxygen saturation; SVR, systemic vascular resistance; SVRI, systemic vascular resistance index; TFC, thoracic fluid content. | ||||
Otero and Garcia Critical Care 2005 9:296 doi:10.1186/cc2982 |
||||