Medication Complications in Extracorporeal Membrane Oxygenation

Predictive models in extracorporeal membrane oxygenation (ECMO): a systematic review

PURPOSE

Extracorporeal membrane oxygenation (ECMO) has been increasingly used in the last years to provide hemodynamic and respiratory support in critically ill patients. In this scenario, prognostic scores remain essential to choose which patients should initiate ECMO. This systematic review aims to assess the current landscape and inform subsequent efforts in the development of risk prediction tools for ECMO.

METHODS

PubMed, CINAHL, Embase, MEDLINE and Scopus were consulted. Articles between Jan 2011 and Feb 2022, including adults undergoing ECMO reporting a newly developed and validated predictive model for mortality, were included. Studies based on animal models, systematic reviews, case reports and conference abstracts were excluded. Data extraction aimed to capture study characteristics, risk model characteristics and model performance. The risk of bias was evaluated through the prediction model risk-of-bias assessment tool (PROBAST). The protocol has been registered in Open Science Framework ( https://osf.io/fevw5 ).

RESULTS

Twenty-six prognostic scores for in-hospital mortality were identified, with a study size ranging from 60 to 4557 patients. The most common candidate variables were age, lactate concentration, creatinine concentration, bilirubin concentration and days in mechanical ventilation prior to ECMO. Five out of 16 venous-arterial (VA)-ECMO scores and 3 out of 9 veno-venous (VV)-ECMO scores had been validated externally. Additionally, one score was developed for both VA and VV populations. No score was judged at low risk of bias.

CONCLUSION

Most models have not been validated externally and apply after ECMO initiation; thus, some uncertainty whether ECMO should be initiated still remains. It has yet to be determined whether and to what extent a new methodological perspective may enhance the performance of predictive models for ECMO, with the ultimate goal to implement a model that positively influences patient outcomes.

Voriconazole Sequestration During Extracorporeal Membrane Oxygenation for Invasive Lung Aspergillosis: A Case Report

The increasing use of extracorporeal membrane oxygenation (ECMO) in critical care introduces new challenges with medication dosing. Voriconazole, a commonly used antifungal and the first-choice agent for the treatment of invasive aspergillosis, is a poorly water-soluble and highly protein-bound drug. Significant sequestration in ECMO circuits can be expected; however, no specific dosing recommendations are available. We report on the therapeutic drug monitoring and clinical evolution of a patient treated with voriconazole for invasive pulmonary aspergillosis while receiving ECMO therapy. Voriconazole trough levels were persistently low (<1 µg/mL) after initiation of ECMO despite additional loading doses and dose increases. Voriconazole dose had to be increased to 6.5 mg/kg three times daily to obtain therapeutic trough levels. The inability to achieve therapeutic levels of voriconazole for a prolonged period (a minimum of 9 days) while undergoing ECMO therapy is believed to have been a significant contributing factor in the patient's fatal outcome. Therapeutic trough levels of voriconazole cannot be guaranteed with standard dosing in patients undergoing ECMO and much higher doses may be necessary. Empirical use of higher doses and/or combination therapy may be reasonable and frequent therapeutic drug monitoring is mandatory.

Hydromorphone Compared to Fentanyl in Patients Receiving Extracorporeal Membrane Oxygenation

Fentanyl is commonly used in critically ill patients receiving extracorporeal membrane oxygenation (ECMO). Fentanyl's lipophilicity and protein binding may contribute to a sequestration of the drug in the ECMO circuit. Hydromorphone lacks these characteristics potentially leading to a more predictable drug delivery and improved pain and sedation management among ECMO patients. This study compared hydromorphone to fentanyl in patients receiving ECMO. This retrospective study included adult patients receiving ECMO for ≥48 hours. Patients were excluded if they required neuromuscular blockade, received both fentanyl and hydromorphone during therapy, or had opioid use before hospitalization. Baseline characteristics included patient demographics, ECMO indication and settings, and details regarding mechanical ventilation. The primary outcome was opioid requirements at 48 hours post cannulation described in morphine milligram equivalent (MME). Secondary endpoints included 24-hour opioid requirements, concurrent sedative use, and differences in pain and sedation scores. No differences were noted between the patients receiving fentanyl (n = 32) or hydromorphone (n = 20). Patients receiving hydromorphone required lower MME compared to fentanyl at 24 hours (88 [37-121] vs. 131 [137-227], p < 0.01) and 48 hours (168 [80-281] vs. 325 [270-449], p < 0.01). The proportion of within-goal pain and sedation scores between groups was similar at 24 and 48 hours. Sedative requirements did not differ between the groups. Patients receiving hydromorphone required less MME compared to fentanyl without any differences in sedative requirements, or agitation-sedation scores at 48 hours. Prospective studies should be completed to validate these findings.

Long-Term Cognitive Outcomes and Sleep in Adults After Extracorporeal Life Support

Objectives:

To assess differences in cognitive outcomes and sleep in adult survivors of critical illness, managed with venovenous extracorporeal membrane oxygenation as compared to conventional mechanical ventilation only.

Design:

Retrospective cohort study linked with data from the COGnitive outcomes and WELLness study.

Setting:

A multisite study from five adult medical/surgical ICUs in Toronto.

Patients:

Thirty-three ICU survivors including adult patients who received venovenous extracorporeal membrane oxygenation (n = 11) matched with patients who received mechanical ventilation only (n = 22) using specified covariates (e.g., age).

Interventions:

None.

Measurements and Main Results:

Baseline demographics and admission diagnoses were collected at enrollment. Cognitive outcome was evaluated using the Repeatable Battery for the Assessment of Neuropsychologic Status (global cognitive function) and Trail Making Test B (executive function), and sleep variables were estimated using actigraphy. Assessments occurred at 7 days post ICU discharge and again at 6- and 12-month follow-up. No statistically significant difference was seen between patients treated with or without venovenous extracorporeal membrane oxygenation in the mean daily Riker Sedation Agitation Score; however, patients in the venovenous extracorporeal membrane oxygenation group received greater amounts of fentanyl over their ICU stay as compared to patients receiving conventional mechanical ventilation only (p < 0.001). No significant differences were found in performance on either of the cognitive assessment tools, between survivors treated or not with venovenous extracorporeal membrane oxygenation at any of the time points assessed. Total sleep time estimated by actigraphy increased from approximately 6.5 hours in hospital to 7.5 hours at 6-month follow-up in all patients, regardless of treatment type. Total sleep time remained consistent in both groups from 6 to 12 months post ICU discharge.

Conclusions:

In this small retrospective case series, no significant differences were found in sleep or cognitive outcomes between extracorporeal life support and non–extracorporeal life support survivors. Further, in this hypothesis-generating study, differences in administered sedative doses during the ICU stay seen between the two groups did not impact 6- or 12-month cognitive performance or actigraphy-estimated sleep time.

Decreasing voriconazole requirement in a patient after extracorporeal membrane oxygenation discontinuation: A case report

Patients receiving extracorporeal membrane oxygenation (ECMO) may display large decreases in drug concentrations due to increases in volume of distribution and drug binding to ECMO circuits, tubing, oxygenator, and coating materials. We report a case of a critically ill male with a 10-month status post-deceased donor renal transplant and being treated with voriconazole for suspected aspergillosis. Initially, multiple dose increases, up to 11.3 mg/kg/dose, were required while on ECMO therapy to obtain goal voriconazole trough concentrations between 2 and 5.5 mcg/mL. The patient's voriconazole dose requirement subsequently decreased to 7.3 mg/kg/dose after ECMO discontinuation, which represented a 45% reduction in voriconazole dose requirement. Based upon this experience, voriconazole appears to bind to artificial surfaces on ECMO devices. In addition to close monitoring of trough levels, it may be appropriate to empirically reduce the voriconazole dose in patients after ECMO discontinuation.

Pharmacokinetics of micafungin in patients treated with extracorporeal membrane oxygenation: an observational prospective study

Objective

To determine micafungin plasma levels and pharmacokinetic behavior in patients treated with extracorporeal membrane oxygenation.

Methods

The samples were taken through an access point before and after the membrane in two tertiary hospitals in Spain. The times for the calculation of pharmacokinetic curves were before the administration of the drug and 1, 3, 5, 8, 18 and 24 hours after the beginning of the infusion on days one and four. The area under the curve, drug clearance, volume of distribution and plasma half-life time with a noncompartmental pharmacokinetic data analysis were calculated.

Results

The pharmacokinetics of the values analyzed on the first and fourth day of treatment did not show any concentration difference between the samples taken before the membrane (Cin) and those taken after the membrane (Cout), and the pharmacokinetic behavior was similar with different organ failures. The area under the curve (AUC) before the membrane on day 1 was 62.1 (95%CI 52.8 - 73.4) and the AUC after the membrane on this day was 63.4 (95%CI 52.4 - 76.7), p = 0.625. The AUC before the membrane on day 4 was 102.4 (95%CI 84.7 - 142.8) and the AUC was 100.9 (95%CI 78.2 - 138.8), p = 0.843.

Conclusion

The pharmacokinetic parameters of micafungin were not significantly altered.

Sedation with alfentanil versus fentanyl in patients receiving extracorporeal membrane oxygenation: outcomes from a single-centre retrospective study

INTRODUCTION

In November 2016, our institution switched from alfentanil to fentanyl for analgesia and sedation in adult patients receiving extracorporeal membrane oxygenation. There is no published evidence comparing the use of alfentanil with fentanyl for sedation in extracorporeal membrane oxygenation patients. We conducted a retrospective observational study to explore any significant differences in patient outcomes or in the prescribing of adjunct sedatives before and after the switch.

METHODS

Patients were retrospectively identified from a prospectively recorded database of all patients who received extracorporeal membrane oxygenation at our institution between January 2016 and October 2017. Patients included those sedated with alfentanil or fentanyl. The total daily doses of intravenous opioids (alfentanil or fentanyl) were calculated for each patient, and the prescribing of adjunctive sedative or analgesic agents was recorded. Patient demographics, extracorporeal membrane oxygenation modality, clinical outcomes including mortality and length of intensive care and hospital stay were recorded.

RESULTS

A total of 174 patients were identified, 69 on alfentanil and 95 on fentanyl. There was no difference found between groups for mode of extracorporeal membrane oxygenation, age, Acute Physiology and Chronic Health Evaluation 2 score (APACHE II) and Charlson score, except for body mass index (p = 0.002). No differences in patient outcomes was observed between groups, although patients in the alfentanil group received a significantly higher median total daily dose of adjuvant sedatives (quetiapine (p = 0.016) and midazolam (p = 0.009)).

CONCLUSIONS

No differences in patient outcomes were found between extracorporeal membrane oxygenation patients sedated with alfentanil compared with fentanyl. There was a statistically significant reduction in some adjunctive sedatives in patients managed with a fentanyl-based regimen. Prospective studies are required to confirm these results.