Methylnaltrexone for Opioid-Induced Dysmotility in Critically Ill Infants and Children: A Pilot Study.

OBJECTIVE: Critically ill pediatric patients commonly experience opioid-induced dysmotility. Methylnaltrexone, a subcutaneously administered, peripherally acting mu-opioid receptor antagonist, is a compelling adjunct to enteral laxatives in patients with opioid-induced dysmotility. Data for methylnaltrexone use in critically ill pediatric patients are limited. The purpose of this study was to determine the effectiveness and safety of methylnaltrexone for opioid-induced dysmotility in critically ill infants and children. METHODS: Patients younger than 18 years who received subcutaneous methylnaltrexone from January 1, 2013, through September 15, 2020, in the pediatric intensive care units at an academic institution were included in this retrospective analysis. Outcomes included incidence of bowel movement, enteral nutrition feeding volume, and adverse drug events. RESULTS: Twenty-four patients, median age 3.5 years (IQR, 0.58-11.1), received 72 methylnaltrexone doses. The median dose was 0.15 mg/kg (IQR, 0.15-0.15). Patients were receiving a mean ± SD of 7.5 ± 4.5 mg/kg/day of oral morphine milligram equivalents (MMEs) at methylnaltrexone administration and received opioids for median 13 days (IQR, 8.8-21) prior to methylnaltrexone administration. A bowel movement occurred within 4 hours following 43 (60%) administrations and within 24 hours following 58 (81%) administrations. Enteral nutrition volume increased by 81% (p = 0.002) following administration. Three patients had emesis and 2 received anti-nausea medication. No significant changes in sedation or pain scores were observed. Withdrawal scores and daily oral MMEs decreased following administration (p = 0.008 and p = 0.002, respectively). CONCLUSIONS: Methylnaltrexone may be an effective treatment for opioid-induced dysmotility in critically ill pediatric patients with low risk of adverse effects.

The Thermal Performance Analysis of an Al2O3-Water Nanofluid Flow in a Composite Microchannel.

Partial filling of porous medium insert in a channel alleviates the tremendous pressure drop associated with a porous medium saturated channel, and enhances heat transfer at an optimum fraction of porous medium filling. This study pioneered an investigation into the viscous dissipative forced convective heat transfer in a parallel-plate channel, partially occupied with a porous medium at the core, under local thermal non-equilibrium condition. Solving the thermal energy equation along the Darcy-Brinkman equation, new exact temperature fields and Nusselt number are presented under symmetrical isoflux thermal boundary condition. Noteworthy is the heat flux bifurcation at the interface between the clear fluid and porous medium driven by viscous dissipation, in cases where the combined hydrodynamic resistance to fluid flow and thermal resistance to fluid conduction is considerable in low Darcy number porous medium insert. However, viscous dissipation does not affect the qualitative variation of the Nusselt number with the fraction of porous medium filling. By using Al2O3-Water nanofluid as the working fluid in a uniformly heated microchannel, partially filled with an optimum volume fraction of porous medium, the heat transfer coefficient improves as compared to utilizing water. The accompanied viscous dissipation however has a more adverse impact on the heat transfer coefficient of nanofluids with an increasing Reynolds number.

Three-percent saline administration during pediatric critical care transport.

OBJECTIVES: The purpose of this study was to describe the administration of 3% saline (3%S) during pediatric critical care transport. METHODS: A retrospective study was performed on pediatric patients who underwent critical transport to Loma Linda University Children's Hospital from January 1, 2003, to June 30, 2007, and were given 3%S. Patients' demographics, admission diagnosis, route and amount of 3%S administration, serum electrolytes, vital signs, radiographic data, and Glasgow Coma Scale scores were collected and analyzed. RESULTS: A total of 101 children who received 3%S infusions during pediatric critical care transport were identified. Mean patient age was 5.9 years, and mean patient weight was 27.6 kg. The main indications for infusing 3%S were suspected cerebral edema (41%), intracranial bleed with edema (51%), and symptomatic hyponatremia (6%). The amount of 3%S bolus ranged from 1.2 to 24 mL/kg, with a mean of 5.4 mL/kg. Serum electrolytes before and after 3%S infusion demonstrated significant increases in sodium, chloride, and bicarbonate levels (P < 0.05). A significant reduction was also seen in serum urea nitrogen levels and anion gap. Radiographic imaging performed before 3%S infusion demonstrated findings consistent with concerns of increased intracranial pressure such as intracranial bleed and cerebral edema. The route of initial 3%S infusions was mainly through peripheral intravenous lines (96%). No complications related to the 3%S delivery such as local reactions, renal abnormalities, or central pontine myelinolysis were observed. CONCLUSIONS: It seems 3%S may be administered safely during pediatric critical transport and administration routes can include peripheral lines. With the importance of initiating therapy early to improve patient outcomes, the use of 3%S may benefit transported children with brain injury and suspected intracranial hypertension.

Intraosseous access in the setting of pediatric critical care transport.

OBJECTIVE: To demonstrate safety and efficacy of intraosseous needle placement among health care provider groups in the setting of pediatric critical care transport. DESIGN: Retrospective chart review. SETTING: Pediatric critical care transports to a pediatric intensive care unit. PATIENTS: Children undergoing pediatric critical care transport between January 1, 2000, and March 31, 2002, requiring intraosseous access before arrival to the pediatric intensive care unit. INTERVENTIONS: Intraosseous access placed for emergent vascular access. MEASUREMENTS AND MAIN RESULTS: During the study period, the transport team performed 1,792 transports and identified 47 patients requiring 58 intraosseous placements. These were placed by emergency medical technician-paramedics (18%), referring emergency medicine physicians (42%), and the transport team members (40%). The intraosseous needles were placed with a mean of 1.2 attempts per placement and a first attempt success rate of 78%. Main site of placement was the proximal anterior tibia (95%). Access was maintained for a mean of 5.2 hrs. The intraosseous needle was used for fluids, medications, and laboratory studies. Admitting diagnoses included respiratory distress (28%), cardiopulmonary arrest (26%), neurologic insults (17%), dehydration (15%), sepsis (11%), and other (3%). Ages ranged from 3 wks to 14 yrs (mean 2.2 yrs) and weights from 2.1 to 60 kg (mean 12.3 kg). Complications were noted in seven of 58 (12%), all limited to local edema or infiltration. CONCLUSIONS: Intraosseous placement is frequently needed in the care of critically ill pediatric patients before they reach the pediatric intensive care unit. We have demonstrated that intraosseous needles can be placed safely with similar rates of success when comparing different provider groups. Emergency medical technician-paramedics, emergency medicine physicians, and pediatric critical care transport teams should be familiar with intraosseous placement.

Alternative arterial catheterization site using the ulnar artery in critically ill pediatric patients.

OBJECTIVE: To examine the patterns of usage and associated complications among radial, femoral, and ulnar artery catheters in the pediatric intensive care unit to ascertain the utility of the ulnar artery as an alternative vessel of peripheral cannulation. DESIGN: A 4-yr retrospective review of all admissions to the pediatric intensive care unit to identify all patients with ulnar, radial, or femoral arterial catheterization. SETTING: Pediatric intensive care unit of a tertiary care pediatric center. PATIENTS: A total of 124 critically ill pediatric patients (age, 0.4-36 mos) were identified. INTERVENTIONS: Ulnar and radial artery catheters were either 22 gauge or 24 gauge, femoral artery catheters were 2.5 Fr, 2.5 cm, or 3 Fr, 5 cm, in size. All catheters were percutaneously inserted. The ulnar artery was typically used when attempts at common peripheral sites were unsuccessful. MEASUREMENTS AND MAIN RESULTS: A total of 18 ulnar, 103 radial, and 69 femoral artery cannulations were identified. The ulnar artery catheter duration ranged from 1 to 19 days (mean, 4.2 +/- 4.2 days), radial artery duration ranged from 1 to 24 days (mean, 5.3 +/- 4.2 days), and femoral artery duration ranged from 1 to 21 days (mean, 6.9 +/- 4.5 days). Ischemia as the reason for catheter removal was 5.6%, 3.9%, and 8.7% for ulnar, radial, and femoral arterial catheters, respectively. The catheter-related infection rate was 0%, 0.97%, and 4.3% for ulnar, radial, and femoral arterial catheters, respectively. CONCLUSION: Based on the ischemic and infectious complication rates, the ulnar artery should be considered as a viable site for peripheral vessel cannulation in cases in which arterial catheterization is necessary and attempts at more common sites of catheterization are unsuccessful.