Quantitative assessment of a pediatric nociception monitor in children under sevoflurane anesthesia.

INTRODUCTION: Intraoperative monitoring of nociception has recently made substantial progress in adult anesthesia. In contrast, pediatric data are scarce. Newborn-Infant Parasympathetic Evaluation (NIPE index, Mdoloris Medical Systems, Loos, France) is the first nociception index specifically designed for young children. It is a dimensionless index comprised between 0 and 100. Two previous studies suggested that NIPE could indeed 'detect' nociception in anesthetized children. The objective of our study was to investigate if NIPE allowed to detect and to provide a quantitative assessment of nociception in children. METHODS: Children were anesthetized with sevoflurane, and received a bolus of alfentanil (10 µg/kg before intubation). Before surgical incision, each participant received three tetanic stimulations (5 s, 100 Hertz) with a 5 min interval, in a randomized order: 10, 30 and 60 milliamps. NIPE and heart rate variations were assessed after each stimulation. RESULTS: Thirty children (2.4±1.6 years) were included. Mean delay between alfentanil and the first stimulation was 19±4 min. Mean baseline NIPE was 75±10. NIPE variation after the stimulations was significant at 10, 30 and 60 mA (linear mixed regression model, p<0.001). The intensity of stimulation significantly influenced the amplitude of NIPE variation (linear mixed regression model p<0.001), but had no statistically significant effect on heart rate variation (p=0.52). DISCUSSION: NIPE might allow a quantitative assessment of nociception in young children in these anesthetic conditions. This study provides a basis for future research investigating the potential benefits of NIPE-guided intraoperative analgesia in pediatric anesthesia. TRIAL REGISTRATION NUMBER: NCT04381637.

Diagnostic yield of routine daily blood culture in patients on veno-arterial extracorporeal membrane oxygenation.

BACKGROUND: Bloodstream infections (BSIs) are frequent on veno-arterial extracorporeal membrane oxygenation (V-A ECMO). Performing routine blood cultures (BCs) may identify early paucisymptomatic BSIs. We investigated the contribution of systematic daily BCs to detect BSIs on V-A ECMO. METHODS: This was a retrospective study including all adult patients requiring V-A ECMO and surviving more than 24 h. Our protocol included routine daily BCs, from V-A ECMO insertion up to 5 days after withdrawal; other BCs were performed on-demand. RESULTS: On the 150 V-A ECMO included, 2146 BCs were performed (1162 routine and 984 on-demand BCs); 190 (9%) were positive, including 68 contaminants. Fifty-one (4%) routine BCs revealed BSIs; meanwhile, 71 (7%) on-demand BCs revealed BSIs (p = 0.005). Performing routine BCs was negatively associated with BSIs diagnosis (OR 0.55, 95% CI [0.38; 0.81], p = 0.002). However, 16 (31%) BSIs diagnosed by routine BCs would have been missed by on-demand BCs. Independent variables for BSIs diagnosis after routine BCs were: V-A ECMO for cardiac graft failure (OR 2.43, 95% CI [1.20; 4.92], p = 0.013) and sampling with on-going antimicrobial therapy (OR 2.15, 95% CI [1.08; 4.27], p = 0.029) or renal replacement therapy (OR 2.05, 95% CI [1.10; 3.81], p = 0.008). Without these three conditions, only two BSIs diagnosed with routine BCs would have been missed by on-demand BCs sampling. CONCLUSIONS: Although routine daily BCs are less effective than on-demand BCs and expose to contamination and inappropriate antimicrobial therapy, a policy restricted to on-demand BCs would omit a significant proportion of BSIs. This argues for a tailored approach to routine daily BCs on V-A ECMO, based on risk factors for positivity.

Acute mesenteric ischaemia in refractory shock on veno-arterial extracorporeal membrane oxygenation.

BACKGROUND: Acute mesenteric ischaemia is a severe complication in critically ill patients, but has never been evaluated in patients on veno-arterial extracorporeal membrane oxygenation (V-A ECMO). This study was designed to determine the prevalence of mesenteric ischaemia in patients supported by V-A ECMO and to evaluate its risk factors, as well as to appreciate therapeutic modalities and outcome. METHODS: In a retrospective single centre study (January 2013 to January 2017), all consecutive adult patients who underwent V-A ECMO were included, with exclusion of those dying in the first 24 hours. Diagnosis of mesenteric ischaemia was performed using digestive endoscopy, computed tomography scan or first-line laparotomy. RESULTS: One hundred and fifty V-A ECMOs were implanted (65 for post-cardiotomy shock, 85 for acute cardiogenic shock, including 39 patients after refractory cardiac arrest). Overall, median age was 58 (48-69) years and mortality 56%. Acute mesenteric ischaemia was suspected in 38 patients, with a delay of four (2-7) days after ECMO implantation, and confirmed in 14 patients, that is, a prevalence of 9%. Exploratory laparotomy was performed in six out of 14 patients, the others being too unstable to undergo surgery. All patients with mesenteric ischaemia died. Independent risk factors for developing mesenteric ischaemia were renal replacement therapy (odds ratio (OR) 4.5, 95% confidence interval (CI) 1.3-15.7, p=0.02) and onset of a second shock within the first five days (OR 7.8, 95% CI 1.5-41.3, p=0.02). Conversely, early initiation of enteral nutrition was negatively associated with mesenteric ischaemia (OR 0.15, 95% CI 0.03-0.69, p=0.02). CONCLUSIONS: Acute mesenteric ischaemia is a relatively frequent but dramatic complication among patients on V-A ECMO.