Perfusion Index as an Indicator for Mortality in Children with Plasmodium falciparum Severe Malaria

Background:Severe malaria (SM) remains a major global health problem causing ~275,000 pediatric deaths annually, worldwide. Continuous, non-invasive monitoring of peripheral perfusion can help detect abnormalities in systemic circulation, a common problem in critically ill patients, and can improve outcomes in children hospitalized with SM. Perfusion index (PI), an indicator of peripheral perfusion measured using a point-of-care pulse oximeter, is the ratio of pulsatile blood flow to static blood in peripheral tissue. Objective: To investigate the role of PI as an indicator of adverse outcomes including mortality in children hospitalized with SM. Methods: We measured PI in a prospective cohort study of 600 children <5 years of age with 5 different clinical manifestations of SM, and 120 healthy community children (CC) at two hospitals in Uganda. PI was measured at 6-hr intervals during hospitalization using a Masimo Rad 57 pulse oximeter. Results: Children with SM had significantly lower admission PI values (1.2 [IQR: 0.58, 2.2] compared to CC (2.8 [1.7, 4.3], p<0.001). Children with SM manifesting as respiratory distress syndrome or severe malarial anemia had lower median PI compared to other manifestations including cerebral malaria, the deadliest form of SM in children. In children with SM, a log decrease in admission PI was associated with 2.7 higher odds of in-hospital mortality (p=0.01). A log reduction in PI was also associated with in-hospital clinical complications associated with SM, including circulatory shock, deep acidotic breathing and acidosis, hypoglycemia, and severe anemia (all P<0.03). In survivors of SM, there were no significant associations between PI and cognitive outcomes at 12-month follow-up. Conclusion: The role of PI as an indicator of mortality in children with SM and the use of point-of-care tools for continuous monitoring of PI warrants further investigation in the management of SM to prevent or reduce the incidence of adverse outcomes.

Monitoring free flaps and replanted digits via perfusion index –A proof of concept study

BACKGROUND: Early detection and treatment of vascular complications in replanted digits is essential for the survival. The perfusion index (PI) represents a marker of peripheral perfusion as it shows the ratio of pulsatile to non-pulsatile blood flow. OBJECTIVE: To evaluate the feasibility and applicability of the PI as a monitoring tool for free flaps and replanted digits by measuring the inter- and intraindividual changes in PI. METHODS: Five patients were postoperatively monitored according to intern standards by hourly clinical evaluation. Additionally, a pulse oximeter with SET-technology® (Masimo Radial 7, Masimo Corporation, Irvine, USA) was added with a LNCS® Red TFA-1 SpO2 sensor (Masimo Corporation, Irvine, USA) and respectively a LNCS® Neo-3 neonatal finger clip to evaluate the perfusion via PI and SpO2. RESULTS: All patients showed sufficient perfusion in clinical controls. There was no detectable vascular complication during follow-up. Mean perfusion index was 0.93 with a median of 0.44. The patients showed a mean SpO2 of 90.59%with a median of 89.21%. CONCLUSION: Our results show a great intra- and interindividual range of PI and SpO2. SpO2 provided an even greater range than PI. Trends in intraindividual PI changes may be a promising monitoring tool for free flaps and replanted digits.

Plethysmographic Peripheral Perfusion Index: Could It Be a New Vital Sign?

The plethysmographic peripheral perfusion index (PPI) is a very useful parameter with various emerging utilities in medical practice. The PPI represents the ratio between pulsatile and non-pulsatile portions in peripheral circulation and is mainly affected by two main determinants: cardiac output and balance between sympathetic and parasympathetic nervous systems. The PPI decreases in cases of sympathetic predominance and/or low cardiac output states; therefore, it is a useful predictor of patient outcomes in critical care units. The PPI could be a surrogate for cardiac output in tests for fluid responsiveness, as an objective measure of pain especially in un-cooperative patients, and as a predictor of successful weaning from mechanical ventilation. The PPI is simple to measure, easy to interpret, and has continuously displayed variables, making it a convenient parameter for detecting the adequacy of blood flow and sympathetic-parasympathetic balance.