These INVOS® System graphs from real patient cases are a compelling way to see the true impact and value of cerebral/somatic monitoring. Each INVOS® System case graph reveals the patient's regional oxygen saturation (rSO2) values at each stage of surgery or critical care treatment, and its responses to events and interventions.
The following case graphs demonstrate how the INVOS® System can make a positive addition to patient care. Its objective, real-time and site-specific oxygenation data helps care teams react to oxygen imbalances, potentially reducing complications, including some potentially catastrophic in scale.
Early Cardiac Decompensation as Visualized by rSO2
AVR, MVP, CABG XI
In this case, an adult cardiac patient experienced significant cerebral desaturation, beginning at induction and even in the face of other hemodynamic parameters being within normal limits. Cerebral ischemia, as captured by the INVOS® System, continued after intubation with developing side-to-side asymmetry. After consultation with the cardiac surgeon, dobutamine and nitroglycerin were started to improve cardiac contractility and reduce afterload. Immediate and dramatic improvements in cerebral oximetry trends were observed with the rSO2 increasing 43 points. This case demonstrates that compromised tissue perfusion in the brain can occur even when traditional measures of perfusion, such as blood pressure, are adequate. Cerebral oximetry monitoring provided a simple, noninvasive way to continuously monitor brain oxygen saturation. This allowed the clinician the opportunity to intervene and correct cerebral ischemia, which if not addressed, may have led to potentially serious neuro complications.
Lack of Ventilation - Effect on rSO2
This case graph is from a young adult undergoing surgery to correct aortic insufficiency and a dilated aorta. The surgery progressed uneventfully until the re-warming phase. During this period, the heart was ejecting and the anesthesiologist was focused on transesophageal echocardiogram (TEE). The ventilator was intermittently turned on and off while surgeon checked for bleeders. The surgeon stepped away while waiting for the patient's body temp to rise due to the prolonged hypothermia phase. At this time, the patient's cerebral rSO2 values plummeted. The perfusionist initiated a number of interventions with no improvement. The ventilator was checked and found to be turned off as the anesthesiologist was preoccupied with the TEE. Once the ventilator was turned on, there was an immediate response with a dramatic rise in the cerebral rSO2.
Effects of Phenylephrine on rSO2
 This case study shows a splenectomy on a relatively healthy, elderly patient. During the induction sequence, this patient's cerebral rSO 2 values rose approximately 20 points; indicative of cerebrovascular CO 2 reactivity. Since the patient's blood pressure was reading 87/55, the CRNA gave a small dose of Phenylephrine, resulting in a profound cerebral desaturation into the low 30s while the BP rose to 95/57 and then higher. This was a surprise since Phenylephrine is reported to work by constricting the peripheral vessels to increase supply to the central circulation. The FiO 2 was increased to 100% and the IV opened to administer a fluid bolus to the patient. The cerebral desaturation resolved within 3 minutes. The INVOS ® System was the only monitor that demonstrated a profound change in cerebral oxygenation related to the dose of Phenylephrine. |
