Corrigendum: Direct vs. redirected admission of critically ill children to PICU after interfacility transfer: a retrospective cohort study.

[This corrects the article DOI: 10.3389/fped.2024.1307565.].

Direct vs. redirected admission of critically ill children to PICU after interfacility transfer: a retrospective cohort study.

Background: Critically ill children must often be transported long distances for access to critical care resources in Canada. This study aims to describe and compare characteristics and outcomes in patients presenting in the community and requiring inter-facility transport and admission to a Pediatric Intensive Care Unit (PICU). Methods: This is a retrospective cohort study of children admitted to the ICU at the Hospital for Sick Children from 2016 to 2019 after inter-facility transport. Characteristics and outcomes were compared between children admitted to the PICU within 24 h from their initial critical care transport request, and children admitted after initial redirection to a non-ICU care setting, 24-72 h from request. The primary outcome was severity of illness at PICU admission. Secondary outcomes included duration of mechanical ventilation, organ dysfunction, PICU length of stay and mortality. Results: A total of 2,730 patients were admitted after inter-facility transport to either the medical/surgical or cardiac ICU within 72 h of initial critical care transport request. Of these children, 2,559 (94%) were admitted within 24 h and 171 (6%) were admitted between 24 and 72 h. Children admitted after initial redirection were younger and residing in more rural centers. Children who were initially redirected had lower severity of illness (PRISM-IV median score 3 vs. 5, p = 0.047) and lower risk of mortality. Interpretation: Initial redirection to a non-ICU care setting rather than directly admitting to the PICU did not result in increased severity of illness or mortality. This study highlights the need to better understand which factors influence disposition decision-making at the time of initial transport request. Further research should focus on the impact of transport factors on clinical outcomes after PICU admission.

Extracorporeal life support: the precarious balance of hemostasis.

Extracorporeal life support is by far the most extraordinary and complex form of extracorporeal technology used in the practice of critical care medicine. It is used to support critically ill patient who suffer acute respiratory or cardiac failure unresponsive to conventional support. As extracorporeal technologies have refined the pathophysiologic reaction that occurs at the blood/biomaterial interface has not been conquered; a new set of physiologic responses/derangements occur with the patient's exposure to the artificial circuit. Without this support mortality is near certain and with support if management is not precise and judicious the complications can be catastrophic. The management of a patient on ECLS is the same as for any critically ill patient with the added need for anticoagulation to maintain patency of the extracorporeal circuit without causing bleeding within the patient and thrombosis within the circuitry or the patient. This is the precarious balance of hemostasis during ECLS.

Safety and efficacy of recombinant activated factor VII for refractory hemorrhage in pediatric patients on extracorporeal membrane oxygenation: a single center review.

BACKGROUND: Medically refractory hemorrhage in patients on ECMO (extracorporeal membrane oxygenation) support can have catastrophic complications. Recombinant-Activated Factor VII (rFVIIa; NovoSeven®) may provide lifesaving hemostasis; however, there are reports of catastrophic thrombosis related to its administration. OBJECTIVE: This review attempts to add safety and efficacy data to existing literature regarding the use of rFVIIa for refractory hemorrhage in pediatric patients on ECMO support. Design/ METHODS: A retrospective chart review was performed for all pediatric patients on ECMO who received rFVIIa for refractory hemorrhage from 2004 to 2009. Data was extracted for each refractory bleeding event, including patient blood loss and transfused blood products in the 6 hours before the first dose, between rFVIIa doses and in the 6 hours after the final dose. For purposes of data collection, a hemorrhagic event was defined as new onset hemorrhage or a hemorrhage occurring at least 12 hours after the most recent dose of rFVIIa. RESULTS: In total, seven patients aged 1 month to 15 years received rFVIIa for 14 different hemorrhagic events. There was no significant difference in blood loss or blood product transfusion associated with rFVIIa administration. There was one patient-related and one ECMO-related complication temporally associated with rFVIIa administration: decreased ECMO circuit oxygenator efficiency and the development of an intra-gastric clot requiring surgical evacuation. CONCLUSION: These data suggest limited efficacy for rFVIIa use for refractory hemorrhage in pediatric patients on ECMO support. There were two non-catastrophic complications temporally associated with its administration.

The use of extracorporeal membrane oxygenation in pediatric patients with sickle cell disease.

Previous reports have described the use of extracorporeal membrane oxygenation (ECMO) for acute chest syndrome of sickle cell disease (SCD). However, there have been no reports of venoarterial (VA) ECMO for cardiac dysfunction in patients with SCD. We describe a patient with SCD and life-threatening cardiogenic shock who was successfully treated with VA ECMO. Furthermore, SCD patients have unique comorbidities that warrant particular consideration when utilizing ECMO. We discuss these considerations and review the documented experience with ECMO for pediatric SCD patients from the Extracorporeal Life Support Organization (ELSO) registry. From 1990 until 2012, 52% of the 65 pediatric patients with SCD placed on ECMO survived, with 85% of those receiving venovenous (VV) ECMO surviving and 43% of those receiving VA ECMO surviving. However, significant complications, such as bleeding, neurological injury and kidney injury, also occurred with both VV and VA ECMO. Ten percent of SCD patients receiving VA ECMO experienced either a cerebral infarct or hemorrhage; our patient suffered a cerebrovascular accident while on ECMO, though she survived with good neurologic outcome. To our knowledge, this is the first report of a pediatric patient with SCD and cardiogenic shock successfully managed with VA ECMO. In conjunction with the ELSO registry review, this case report suggests that, while VA ECMO can be successfully used in patients with SCD and severe cardiovascular dysfunction, clinicians should also be aware of the potential for serious complications in this high-risk population.

The dependency of expiratory airway collapse on pump system and flow rate in liquid ventilated rabbits.

PURPOSE: To evaluate the influence of pump system and flow pattern on expiratory airway collapse (EAC) in total perfluorocarbon ventilation. - METHODS: Prospective, controlled, randomized animal trial for determination of (1) post-mortem changes by repeated expiration procedures (EP) with a constant flow piston pump (PP) before and after sacrifice (n = 8 rabbits), (2) differences between pump systems by subjecting animals to both PP and roller pump (RP) circuits for expiration (n = 16 rabbits). EP were performed using a servo-controlled shut-off at airway pressures < 25 cm H subset 2O randomly with either pump at different flows. - RESULTS: Expired volumes before and after sacrifice were not significantly different. PP and RP revealed identical mean flows, while significantly more liquid was drained using PP (p<0.05). Increasing differences towards higher flow rates indicated profound flow pulsatility in RP. - CONCLUSIONS: (1) post-mortem changes in expired volumes are not significant, (2) EAC is related to flow rate and pump system; (3) relationship between expiratory flow rate and drainable liquid volume is linear inverse; (4) PP provides higher drainage than RP. - SUMMARY STATEMENT: Expiratory airway collapse is related to flow rate and pump system, post mortem changes in expirable volumes are not significant. Relationship between expiratory flow rate and drainable liquid volume is linear inverse, piston pump expiration provides higher drainage volumes than roller pump expiration.

Reduced platelet activation and thrombosis in extracorporeal circuits coated with nitric oxide release polymers.

OBJECTIVE: To determine whether the use of nitric oxide (NO)-releasing polymers coated onto the inner surface of extracorporeal circuits can reduce platelet consumption and activation in the absence of systemic heparinization using a rabbit model of venovenous extracorporeal circulation. DESIGN: Prospective, controlled trial. SETTING: Research laboratory at an academic medical institution. SUBJECTS: New Zealand White Rabbits. INTERVENTIONS: Anesthetized, tracheotomized, and ventilated New Zealand White rabbits were injected with freshly prepared, 111In(oxine)3 labeled single donor platelets through the external jugular vein. After baseline measurements, these animals were placed on venovenous extracorporeal circulation through a 1-m control circuit or NO test circuit for 4 hrs at a blood flow rate of 109-118 mL/min via roller pump. Four groups were studied: systemically heparinized control circuits, systemically heparinized NO test circuits, nonheparinized control circuits, and nonheparinized NO test circuits. Platelet counts, fibrinogen levels, and plasma free indium levels were measured hourly. Circuits were rinsed and retained for gamma counting after the 4-hr run or when the circuit clotted. Four animals, one from each group, did not receive radiolabeled platelets so that the circuits could be preserved for scanning electron microscopic examination after the 4-hr study. MEASUREMENTS AND MAIN RESULTS: Platelet consumption was significantly reduced in both the heparinized and nonheparinized NO test groups when compared with the controls (p < .0001 and p < .0004, respectively). Platelet adhesion to the extracorporeal circuits was significantly reduced in the nonheparinized test circuits when compared with the controls (p < .05). Scanning electron microscopic examination of the circuits revealed that in the absence of heparin and in the presence of a NO-releasing surface, platelets retained their spherical nonactivated shape. CONCLUSIONS: The incorporation of NO into the surface of extracorporeal circuits reduces platelet consumption and eliminates the need for systemic heparinization in a rabbit model of extracorporeal circulation.

Venovenous versus venoarterial extracorporeal life support for pediatric respiratory failure: are there differences in survival and acute complications?

OBJECTIVES: To examine the Extracorporeal Life Support Organization (ELSO) registry database of infants and children with acute respiratory failure to compare outcome and complications of venovenous (VV) vs. venoarterial (VA) Extracorporeal Life Support (ECLS). DESIGN: Retrospective cohort study. SETTING: ELSO registry for pediatric pulmonary support. PATIENTS: All nonneonatal pediatric pulmonary support ECLS cases treated at U.S. centers and reported to the ELSO registry as of July 1997. Patients were excluded if they had one or more of the following diagnoses: hematologic-oncologic, cardiac, abdominal surgical, burn, metabolic, airway, or immunodeficiency disorder. INTERVENTIONS: Venoarterial or venovenous extracorporeal life support for severe pulmonary failure. MEASUREMENTS AND MAIN RESULTS: From 1986 to June of 1997, 763 pediatric patients met the inclusion criteria. Overall, 595 were initially managed with VA bypass, and 168 with VV bypass. The VA group was younger (mean +/- SD, 26.1+/-42.2 months for VA vs. 63.5+/-68.7 months for VV) and smaller (11.8+/-15.1 kg vs. 22.9+/-23.8 kg) (p<.001). There were no differences between groups in number of days on mechanical ventilation before ECLS, number of hours on ECLS, or number of hours on mechanical ventilation post-ECLS in survivors. Mean pH and Paco2 values, positive end-expiratory pressure, and mean airway pressure just before placing the patient on ECLS were also similar. VA-treated patients had higher Fio2 requirements (p = .034), lower Pao2 (p = .047), and lower Pao2/Fio2 ratio (p = .014) just before cannulation. There was a trend of higher peak inspiratory pressure in VA-treated patients (p = .053). Overall, survival rate was not different for the two groups (55.8% for VA vs. 60.1% for VV; p = .33). Central nervous system complications were not different between the two groups. Examination of the same variables was then conducted after dividing the patients into four subgroups. There were no significant differences in survival or complications during bypass between VV and VA modes of ECLS in any subgroup. Stepwise logistic regression modeling was performed to control for variables associated with the outcome survival for VV and VA-treated groups, and variables measured before bypass were identified as being associated with improved survival. There was a trend of improved survival in the VV-treated patients (p = .12). CONCLUSIONS: Overall survival of pediatric patients with acute respiratory failure supported by VA or VV ECLS was comparable. A randomized clinical trial may be useful in clarifying these observations.

Effect of blood flow rate on thrombogenesis in a rabbit extracorporeal circulation model.

Blood flow is believed to affect the thrombogenicity of extracorporeal circulation (ECC). The purpose of this study was to look at the relationship between blood flow and thrombogenicity in a rabbit model of ECC. Rabbits were anesthetized and systematically heparinized. Bilateral jugular cannulation was performed, and the animals were placed on venovenous ECC. The circuits were composed of 1 m of 1/4 inch size surgical grade polyvinylchloride (PVC) tubing. ECC was maintained for 4 hours. Three experimental groups were studied: a high flow group (n=7; flow rate: 30 ml/min/Kg), low flow group (n=7; flow rate: 10 ml/mg/Kg), and no ECC group (n=7). Platelet count, fibrinogen concentration, PaO2/FiO2, and postmortem findings were evaluated. Platelet consumption was higher with high flow, and fibrinogen consumption was higher with low flow.