Introduction
The FORE-SIGHTTM monitor measures absolute cerebral tissue oxygen saturation (SctO2) of the frontal lobes of the brain, in a non-invasive way, through near-infrared spectroscopy (NIRS) [1]. Its value for early detection of hemodynamic deterioration in the postoperative phase after congenital cardiac surgery has never been examined. In a prospective observational study [2], 300 mechanically ventilated patients younger than 12 years after cardiac surgery will be monitored with NIRS, in addition to their routine haemodynamic monitoring. The NIRS monitor is blinded to clinicians, and its predictive value to detect predefined critical hemodynamic events will be analysed.
Objectives
To compare SctO2 in relationship to the arterial oxygen saturation (SaO2) and central venous oxygen saturations (ScvO2), in children with cyanotic (CC) and non-cyanotic cardiopathy (NCC) admitted to the paediatric intensive care unit (PICU) after congenital cardiac surgery.
Methods
The present study is a preliminary report of baseline data and monitored values of the first 136 children included in the abovementioned prospective observational FORE-SIGHTTM study.
Results
The results are summarized in table 1 and table 2. 83 children were admitted with a CC, 53 with NCC, and 57.3% were boys. Patients in the CC-subgroup had a longer median PICU length of stay, had lower mean arterial blood pressures, and higher haemoglobin levels compared to patients in the NCC-subgroup. Evidently, CC-patients had a lower mean SaO2. There was a non-significant trend towards lower ScvO2 and SctO2 values in the CC subgroup (which was significant for L- SctO2). ScvO2 was significantly lower than SctO2 in the CC-subgroup (p=0.002), but not in the NCC-subgroup (p=0.28).
Table 1
| Overall | Cyanogenic | Non-Cyanogenic | p-value (*) | |
|---|---|---|---|---|
| Number (boy/girl ratio) | 136 (57.3%) | 83 (56.6%) | 53 (58.5%) | |
| Age in months: median (IQR) | 5.5 (2-18.5) | 5 (2-19.8) | 6 (2-17) | 0.61 |
| PICU LOS in days: median (IQR) | 5 (3-9) | 6 (4-12) | 3 (2-6) | 0.0004 |
| Hemoglobin (g/dl) | 10.9 (1.2) | 11.1 (1.2) | 10.5 (1.1) | 0.005 |
| Mean arterial pressure (mmHg) | 63.7 (9.6) | 61.7 (9.5) | 66.8 (9.1) | 0.003 |
| Mean and SD was reported, except for age and ICU LOS. (*) P-value of the comparison of the cyanogenic and non-cyanogenic groups. T-test was used to compare means, Wilcoxon ranking-test for medians. | ||||
Table 2
| Overall | Cyanogenic | Non-Cyanogenic | p-value (*) | |
|---|---|---|---|---|
| SaO2 (%) | 92.7 (7.4) | 90.7 (8.0) | 95.7 (4.9) | < <0.0001 |
| ScvO2 (%) | 67.3 (12.7) | 65.5 (11.9) | 70.8 (13.7) | 0.07 |
| L-SctO2 (%) | 71.6 (7.2) | 70.6 (7.8) | 73.1 (5.9) | 0.04 |
| R-SctO2 (%) | 71.3 (6.9) | 70.5 (7.7) | 72.6 (5.2) | 0.08 |
| A-SctO2 (%) | 71.7 (6.5) | 70.8 (7.3) | 73.1 (4.8) | 0.06 |
| ScvO2 < A-SctO2 | p=0.002 | p = 0.28 | ||
| Mean and SD was reported, except for age and ICU LOS. (*) P-value of the comparison of the cyanogenic and non-cyanogenic groups. T-test was used to compare means, Wilcoxon ranking-test for medians. | ||||
Conclusions
Notwithstanding the lower observed SaO2, CC patients are able to preserve brain tissue oxygenation as measured by NIRS, which is significantly higher than their ScvO2. The additional predictive value of NIRS in this setting will be assessed in the ongoing Fore-sight study.
Trial Registration
Clinical trial registered with www.clinicaltrials.gov (NCT01706497).
Grant Acknowledgment
Foundation for Scientific Research Flanders (FWO) (G. 0904.11). Senior clinical investigator, FWO to Geert Meyfroidt (1846113N). Methusalem program, Flemish Government to Greet Van den Berghe (METH/08/07).
References
- 1.Fisher GW, Silvay G. Cerebral oximetry in cardiac and major vascular surgery. HSR Proc Intensive Care Cardiovasc Anesth. 2010;2(4):249–256. [PMC free article] [PubMed] [Google Scholar]