Juan P. Gurria, MD and J. Craig Egan, MD Phoenix Children’s Hospital, Phoenix, AZ, USA Despite common use of bedside clinical signs to categorize type of pediatric septic shock, there is inconsistent agreement between these signs. Extremity temperature, capillary refill, and pulse strength exhibited fair‐to‐good agreement with each other, while diastolic blood pressure and pulse pressure exhibited poor agreement. Prior studies have demonstrated that direct measurement of cardiac index and systemic vascular resistance can be used to categorize shock type and guide vasoactive therapy in children with septic shock. For patients treated with vasoactive medications as part of the sepsis pathway, neither shock type nor any of the clinical signs of shock type were strongly matched with vasoactive selection, and the resulting shock type‐vasoactive mismatch was not associated with complicated course or worse clinical outcomes. These data support recent Surviving Sepsis campaign recommendations that clinical signs should not be used in isolation to categorize shock type. Answer: E Walker, S.B., et al., Clinical signs to categorize shock and target vasoactive medications in warm versus cold pediatric septic shock. Pediatric Critical Care Medicine , 2020. 21 (12): pp. 1051–1058. By 4 days of ECMO, 50% of ECMO users experience a “bleeding day.” The proportion of patients bleeding on each day of ECMO run does not vary significantly as duration increases. Bleeding days occurred more frequently in older patients, patients with congenital cardiac diagnosis, patients who had a bleeding event before ECMO initiation, had surgery before ECMO, were centrally rather than peripherally cannulated, had ECMO initiated with crystalloid solution rather than blood primed circuit, and those who received veno‐arterial ECMO compared with veno‐venous ECMO. Laboratory values on bleeding days were notable for higher lactate levels and prothrombin times, as well as lower platelet counts, compared with nonbleeding days. Bleeding patients, those who were over the 75% percentile with regards to bleeding frequency, resulted in patients who met study criteria for “bleeding day,” recognized as frequent bleeding in 26% of their ECMO run. These patients compared with the remainder of the cohort, had fewer ventilator‐free and hospital‐free days in the 2 months after cannulation, and higher in‐hospital mortality rate. Answer: B O’Halloran, C.P., et al., Mortality and factors associated with hemorrhage during pediatric extracorporeal membrane oxygenation. Pediatric Critical Care Medicine , 2020. 21 (1): pp. 75–81. Walker, S.B., et al., Clinical signs to categorize shock and target vasoactive medications in warm versus cold pediatric septic shock. Pediatric Critical Care Medicine , 2020. 21 (12): pp. 1051–1058. Up to 37% of critically ill children admitted to the PICU develop acute kidney injury (AKI). AKI is strongly associated with prolonged ICU and hospital length of stay (LOS). Recent studies reported a mortality from severe AKI in PICU between 11 and 64%. Those who underwent cardiopulmonary bypass had an adjusted odds ratio of 2.5. Even those who survive to discharge have an increased risk of repeat hospitalizations and physician visits. Furthermore, AKI in PICU is independently associated with long‐term mortality beyond 5 years after PICU discharge. A proportion of the children who survive develop hypertension, and/or are dependent on renal support after discharge. Answer: A Raman, S., et al., Prediction of acute kidney injury on admission to pediatric intensive care. Pediatric Critical Care Medicine , 2020. 21 (9): pp. 811–819. The most common location for a thrombus to occur was femoral (44%). Thrombosis was most commonly associated with percutaneous CVCs (51%). On univariate analysis, those factors associated with risk of thrombosis are as follows: age, STAT placement, total catheter days, multiple catheters concurrently in situ, history of a cardiac catheter intervention, cardiac arrest, use of mechanical circulatory support, chylothorax, prior infection, open chest, unplanned reintervention, and history of CLABSI. In multivariable analysis, independent predictors of thrombosis were younger age, STAT placement, 4–5 total catheter days, history of mechanical circulatory support, and unplanned reintervention. Patients with PICC line associated thrombosis do not require immediate removal provided that the patient continues to require the line, the line is functional, and anticoagulation is started. Answer: B DiPietro, L.M., et al., Central venous catheter utilization and complications in the pediatric cardiac ICU: a report from the pediatric cardiac critical care consortium (PC4). Pediatric Critical Care Medicine , 2020. 21 (8): pp. 729–737. One study (Norii et al.) evaluated the mortality and characteristics of children with severe traumatic injury who received REBOA. This study retrospectively reviewed 54 patients less than or equal to 18 years of age using the Japan Trauma Data Bank from 2004 to 2015. Patients had high anatomic injury severity scores (ISS) (median 41.2) with a survival rate of approximately 43%, similar to those found in adult patients who receive REBOA. However, it should be noted that most [n = 39, (72%)] children in this retrospective study were between 16 and 18 years of age, and only one child less than 10 years of age received REBOA. They concluded that both young children and adolescents who underwent REBOA were seriously injured with high ISS and had equivalent survival rates compared to reported survival rates from studies in adults. These results and conclusions are supported by an unpublished study performed in the United States that indicates REBOA is safe for use in adolescents despite their smaller caliber vasculature. A 12 Fr sheath has an outer diameter of 4.67 mm and is often too large for very young pediatric patients. The 12 Fr‐compatible REBOA catheter was the only commercially available catheter in the United States until 2016, when the 7 Fr sheath, whose outer diameter is only 3 mm, was introduced. Carrillo et al. used the approximate aortic diameters from CT scans of 289 patients to create artificial aortas using a three‐dimensional (3D) printer. The aortas were then inserted into a circulatory system model that both simulated abdominal and upper body perfusion. Sonographic flow meters and pressure transducers were placed along the circuit, and measurements were recorded as REBOA device was inflated in the aortic segment. Zone 1 and 3 aortic diameters were measured and grouped according to pediatric Broselow category. Recommendations were then made for REBOA inflation volumes according to the results (Table 24.1). Table 24.1 Recommended initial REBOA inflation volumes and zone distances (cm) for the five largest Broselow categories.a a Inflation volume based on occlusion of flow by approx. 75%. REBOA‐resuscitative endovascular balloon occlusion of the aorta. Adapted from Carrillo et al. Pediatric trauma surgeons should become familiar with the indications and technique for REBOA, and establishing institutional protocols in conjunction with vascular surgery or interventional radiology may be a consideration at free‐standing pediatric trauma centers. Inserting the commercially available catheters requires minimal training that most pediatric surgeons skilled in vascular access should be comfortable with if interventional radiologists or vascular surgeons are not rapidly available. Answer: C Campagna, G.A., et al., The utility and promise of Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) in the pediatric population: an evidence‐based review. Journal of Pediatric Surgery , 2020. 55 (10): pp. 2128–2133. The rate of fluid overload in the pediatric severe TBI population is high, especially in infants under 1‐year old. However, unlike other PICU cohorts, fluid overload does not appear to be associated with worse clinical outcomes in the severe TBI patients. Hypertonic saline does not appear to be a contributing factor to the high rate of fluid overload in severe TBI. Intracranial hypertension is a common sequela of severe TBI. Evidence‐based guidelines recommend treatment of increased intracranial pressure (ICP) using a multisystem approach, including the use of hyperosmolar therapy. Hyperosmolar therapy creates an osmotic gradient that draws water from the interstitium into the vascular space. Mannitol and hypertonic saline represent two of the most commonly used hyperosmolar therapies. Mannitol is a sugar alcohol that works as an osmotic diuretic to raise serum osmolarity. Although very effective in lowering ICP, the brisk diuresis that occurs with mannitol in pediatric patients can lead to hypotension and an overall decrease in cerebral perfusion pressure. In contrast, hypertonic saline lowers the ICP without the diuretic effect seen with mannitol and acts as an intravascular volume expander, thus supporting the blood pressure. These hemodynamic differences have led to an increased use of hypertonic saline for the treatment of pediatric TBI. There was no significant difference in clinical outcomes for the fluid overloaded group when compared with the group without fluid overload. After adjusting for differences in clinical and demographic variables, there was no increase in odds of mortality when comparing fluid overloaded versus children without fluid overload. There was also no significant increase in odds of AKI. There was no change in the mean PICU LOS (8.5 vs 9.3 days in non‐fluid overload vs fluid overloaded children, respectively),and there was also no change in the mean ventilator‐free days (14.6 vs 13.0 days in non‐fluid overload vs fluid overloaded children, respectively). AKI has been associated with the use of hypertonic saline, but this was seen with sustained sodium greater than 170 mmol/L. Answer: E Stulce, C., et al., Fluid overload in pediatric severe traumatic brain injury. Pediatric Critical Care Medicine , 2020. 21 (2): pp. 164–169.
24
Pediatric Critical Care
Broselow Category
Average age (years)
Average weight (kg)
Inflation at zone 1: Aorta at the xyphoid process (ml)
Inflation at zone 3: Aorta at the umbilicus (ml)
Zone I‐zone 3 distance (cm)
Black
12.3
49.1
7.5
5.5
21.8
Green
9.4
33.5
6
3.5
14.5
Orange
7.3
26.3
5.5
3
13.0
Blue
5.5
21.2
5
2
12.8
White
3.6
18.3
3
1.5
11.8