ABSTRACT
Temporary mechanical circulatory support is increasingly used, particularly in patients with cardiogenic shock or during high-risk percutaneous coronary interventions. In the last five years there have been numerous developments in this field. Experience has been gained from usage of temporary heart pumps, and new pumps have arrived on the market. Until recently, the intra-aortal balloon pump was the standard treatment for patients with cardiogenic shock; however, results from the latest research into the effectiveness of this pump have rendered it less popular. An alternative modality is the Impella system. Since 2012, usage of a heart pump in cardiogenic shock treatment is reimbursed by healthcare insurers in the Netherlands. Recently, the FDA approved the Impella system for said indication.
Subject(s)
Heart-Assist Devices/standards , Shock, Cardiogenic/therapy , Humans , Intra-Aortic Balloon Pumping/standards , Netherlands , Percutaneous Coronary Intervention , Treatment OutcomeABSTRACT
BACKGROUND: Pulse pressure variation (PPV) and systolic pressure variation (SPV) are reliable predictors of fluid responsiveness in patients undergoing controlled mechanical ventilation. Currently, PPV and SPV are measured invasively and it is unknown if an arterial pressure (AP) signal obtained with a finger cuff can be used as an alternative. The aim of this study was to validate PPV and SPV measured using a finger cuff. METHODS: Patients receiving mechanical ventilation under sedation after cardiac artery bypass graft (CABG) surgery were included after arrival on the intensive care unit. AP was measured invasively in the radial artery and non-invasively using the finger cuff of the Nexfin™ monitor. I.V. fluid challenges were administered according to clinical need. The mean value of PPV and SVV was calculated before and after administration of a fluid challenge. Agreement of the calculated PPV and SPV from both methods was assessed using the Bland-Altman analysis. RESULTS: Nineteen patients were included and 28 volume challenges were analysed. Correlation between the two methods for PPV and SPV [mean (sd)=6.9 (4.3)% and 5.3 (2.6)%, respectively] was r=0.96 (P<0.0001) and r=0.95 (P<0.0001), respectively. The mean bias was -0.95% for PPV and -0.22% for SPV. Limits of agreement were -4.3% and 2.4% for PPV and -2.2% and 1.7% for SPV. The correlation between changes in PPV and SPV as a result of volume expansion measured by the two different methods was r=0.88 (P<0.0001) and r=0.87 (P<0.0001), respectively. CONCLUSIONS: In patients receiving controlled mechanical ventilation after CABG, PPV and SPV can be measured reliably non-invasively using the inflatable finger cuff of the Nexfin™ monitor.
