ABSTRACT
Near-infrared spectroscopy (NIRS) is non-invasive, easy to use, and offers real-time monitoring of the oxygen content of cerebral tissue. An effective and user-friendly method of cerebral monitoring stands to offer a significant advance in patient care during adult cardiac surgery, particularly for surgery in which the continuity of cerebral vessels may be compromised. While the current evidence does not definitively show improvement in neurological outcomes, it can be argued that the overall risk to benefit ratio falls on the side of NIRS. NIRS also gives information about the oxygenation of systemic tissues. It may be that in surgery that does not involve the aortic arch, the value of NIRS will be in increased individualisation of patient management and improved systemic perfusion, impacting general outcomes as much as neurological outcomes. This review will summarise the need for neuromonitoring and the principles of NIRS. It will examine the thresholds used to define desaturation, the evidence for clinical benefit from NIRS, and the criticisms and limitations of NIRS. It will also discuss the uses of NIRS beyond improving neurological outcomes alone.
Subject(s)
Aorta, Thoracic/surgery , Brain Ischemia/prevention & control , Cardiac Surgical Procedures/methods , Spectroscopy, Near-Infrared/standards , Adult , Aorta, Thoracic/physiopathology , Brain Ischemia/diagnosis , Cardiac Surgical Procedures/adverse effects , Cardiopulmonary Bypass/adverse effects , Cardiopulmonary Bypass/methods , Female , Humans , Male , Middle Aged , Monitoring, Intraoperative/standards , Needs Assessment , New Zealand , Oxygen Consumption , Risk Assessment , Standard of Care , Treatment OutcomeABSTRACT
BACKGROUND: Isolated replacement of the tricuspid valve is rare, and the decision to operate is difficult. This study reviews the in-hospital mortality and long-term survival after tricuspid valve replacement in the absence of concomitant left sided valve surgery. It identifies predictors of poor outcome. METHODS: All patients who underwent tricuspid valve replacement between January 1995 and December 2011 were retrospectively reviewed. Patients having concomitant mitral or aortic valve surgery were excluded. Logistic regression was used to identify predictors of early and late death. RESULTS: Twenty-nine cases were identified. There were six in-hospital deaths (20.6%), and eight late deaths. Ascites was associated with in-hospital death (hazard ratio 16.96; p=0.0052). Higher dose of Frusemide was associated with late mortality (hazard ratio 1.157 per 20mg increase; p=0.0155). Frusemide dose and ascites were both significantly associated with death overall (p<0.01). Survival analysis estimated a 50% probability of surviving to 12.45 years. CONCLUSIONS: Isolated tricuspid valve replacement has a high peri-operative risk. Long-term survival in this study was consistent with other reports. Ascites and higher doses of Frusemide were associated with poor outcomes.