9.2 Pediatrics, Immunocompromised, Oncology & Bariatrics

Pediatric, oncology/immunocompromised, and bariatric adaptations

Domain 2B also covers children, patients with impaired immunity or cancer treatment, and individuals with obesity who need infusion therapy. Defaults that work for a healthy young adult can fail these populations through wrong gauge, wrong volume, weak asepsis, or inaccessible veins.

Quick Answer: Pediatrics = developmental care + family partnership + weight-based dosing/volumes + smaller devices + careful site choice (scalp/foot in infants when appropriate) + overload sensitivity; use midlines/PICCs for longer therapy when indicated. Immunocompromised/oncology = strict asepsis, neutropenic infection vigilance, central access for many vesicants, ports for intermittent chemo, relentless extravasation surveillance. Bariatrics = ultrasound for difficult access, longer needles for ports, skin-fold hygiene, and ideal vs actual weight dosing principles with pharmacy support.

Pediatrics

Developmental stages and communication

Children are not small adults. Developmental stage shapes fear, cooperation, site choice, and teaching targets (child vs caregiver).

Family-centered care

Parents and guardians are partners, not visitors who get in the way. Family-centered infusion practice includes:

• Explaining the plan, alternatives, and what success looks like
• Teaching caregivers to report infiltration signs (swelling, coolness, pain, blanching, leakage)
• Defining who may touch the line and how to protect it during holding, feeding, and play
• Using child life specialists when available for procedural support, distraction, and coping
• Documenting education and demonstrating pump/alarms for home or step-down care when relevant

Exam emphasis: Coercion and surprise sticks without preparation are poor practice when time allows planned, supported access.

Site selection unique to pediatrics

Adult forearm-first rules still matter when forearm veins are usable, but infants and young children expand the map:

Always weigh infection risk, mobility, and therapy duration. Lower-extremity access in ambulatory older children/adults is generally discouraged as routine first-line practice.

Gauge, length, and device escalation

• Use smaller gauges appropriate to vein size and ordered therapy (often 22–24 gauge class devices in many pediatric contexts—match product and vein, not adult habit).
• For longer therapy, repeated failed short PIVs harm children psychologically and damage veins—evaluate midlines or PICCs when duration and infusate profile support them.
• Central access is indicated when therapy chemistry or duration demands it (vesicants requiring central hemodilution, PN requiring central administration, multi-lumen complex needs)—not merely because the child is “hard to stick” once.

Weight-based dosing and fluid volumes

Nearly all pediatric medication doses and many fluid prescriptions are weight-based (and sometimes surface-area-based for oncology regimens). Infusion nurses must:

• Verify that the current weight used for calculation is documented and plausible
• Use smart-pump drug libraries and independent double-checks per high-alert medication policy
• Question adult default rates copied onto a pediatric order
• Recognize fluid overload sensitivity—children, especially infants, can develop pulmonary edema or electrolyte shifts with relatively small absolute volume errors

Maintenance fluid concepts and deficit replacement are ordered by providers; your job is accurate delivery, monitoring, and escalation when intake exceeds tolerance (tachypnea, edema, rising weight, hyponatremia concerns with free water, etc.).

Securement and psychological safety

Pediatric devices are frequently pulled by curious hands. Engineered securement, protective wraps that still allow site inspection, and distraction during care reduce both dislodgement and trauma. Never substitute hiding a deteriorating site under opaque wraps that prevent assessment.

Immunocompromised and oncology populations

Strict asepsis as survival care

Patients with cancer, transplant, high-dose steroids, or other immunocompromise have reduced ability to fight line-related infection. A “small” break in aseptic technique can become life-threatening bacteremia.

Core habits (reinforced, not relaxed):

• Hand hygiene before every line contact
• Thorough needleless connector disinfection and “scrub the hub” adherence
• Sterile dressing changes on schedule and when damp/loose/soiled
• Minimize unnecessary hub entries and blood draws from central lines when alternatives exist and policy prefers peripheral sticks for labs
• Prompt removal of devices that are no longer indicated

Neutropenic precaution concepts

Neutropenia (low neutrophil count) markedly elevates infection risk. Exact absolute neutrophil count thresholds and isolation protocols are facility- and protocol-specific, but exam-level concepts include:

• Heightened surveillance for fever, chills, rigors, new cough, mucositis pain, or subtle change in mental status
• Understanding that fever in neutropenia is a medical emergency pathway—rapid assessment and ordered cultures/antibiotics save lives
• Protecting skin and mucosal barriers; meticulous oral and perianal care as part of the broader plan
• Avoiding unnecessary invasive procedures and protecting existing CVADs as critical lifelines

You do not need memorized ANC cutoffs invented for the exam; you need the principle that infection prevention intensity rises as host defenses fall.

Vascular access for chemotherapy and vesicants

Many antineoplastic agents are irritants or vesicants. Vesicants can cause severe tissue necrosis if extravasated. Continuous or high-risk vesicant administration generally requires appropriate central venous access with confirmed tip location—not a short PIV used because it was convenient.

Port care essentials: Use correct non-coring (Huber-type) needles, confirm blood return per protocol before vesicant administration, maintain sterile access technique, de-access properly, and flush/lock per policy. Report pocket infection signs (erythema, warmth, drainage, fever).

Extravasation vigilance

For any vesicant or high-risk irritant:

1. Verify patency and blood return before and during administration per protocol.
2. Educate the patient to report burning, stinging, pain, or swelling immediately—do not minimize complaints.
3. If extravasation is suspected: stop the infusion, do not automatically flush a vesicant into tissue, follow the drug-specific extravasation protocol (antidote, cold/warm, elevation, marking the area, photo documentation, provider notification).
4. Leave the catheter in place only if protocol needs it for aspiration/antidote delivery—know the principle of protocol-driven action rather than improvisation.

Exam trap: Continuing a vesicant because “the pump pressure is only a little high” or because the nurse is behind schedule.

Holistic oncology infusion notes

• Anticipate nausea, hypersensitivity, and cytokine-related reactions for selected agents—emergency meds and stop rules must be immediately available when protocols require them.
• Hazardous drug handling (PPE, closed-system transfer devices, spill response) protects staff and families; details expand in hazardous-drug domains, but oncology access care always sits inside that safety culture.
• Emotional support and clear communication reduce anxiety that leads to line pulls and missed therapy.

Bariatric considerations

Difficult venous access

Obesity can obscure veins under adipose tissue, deepen targets, and increase first-stick failure. Best-practice response is skill escalation—not repeated blind trauma.

• Ultrasound guidance is often essential for peripheral and midlines/PICC evaluation.
• Assess for usable veins in multiple regions; avoid assuming “no veins” after one failed visual attempt.
• Longer catheter lengths may be needed so enough catheter resides intravascularly after soft-tissue depth is accounted for (a short catheter that only barely enters a deep vein will infiltrate with motion).
• Secure carefully: motion under thick soft tissue can hide early infiltration—compare limbs, heed pain, watch pump occlusion trends.

Implanted ports and longer needles

Ports in patients with significant subcutaneous tissue may require longer non-coring needles to fully seat in the port reservoir. Incomplete needle length leads to:

• Infiltration of infusate into subcutaneous tissue (including vesicant disaster if chemo is running)
• Inability to obtain blood return
• Pocket swelling and pain

Always confirm needle length selection against tissue depth and product guidance; reassess if body habitus changes after major weight loss/gain or surgery.

Skin folds, moisture, and site care

Skin folds trap moisture, yeast, and bacteria. Insertion sites or port pockets near folds need:

• Thorough skin antisepsis with adequate dry time
• Dressings that stay intact in humid environments—change when compromised
• Inspection for intertrigo, candidiasis, and hidden erythema under pannus when relevant to access pathways
• Patient teaching on hygiene and when to call for dressing problems

Dosing weight principles (without invented formulas)

Some medications are dosed on actual body weight, others on ideal body weight, adjusted body weight, or capped doses. Obesity alters volume of distribution for lipophilic drugs and may change clearance. The CRNI-level expectation is conceptual:

• Know that weight selection for dosing is drug-specific and pharmacy-driven
• Verify which weight was used when orders seem extreme for the clinical picture
• Do not apply a single homemade “always use ideal weight” rule across all drugs
• Monitor for underdosing (treatment failure) and overdosing (toxicity) when weight-based infusions run in bariatric patients
• Collaborate with pharmacy and the prescriber whenever weight, renal function, and drug choice interact

Bariatric surgery history may also affect oral absorption and nutritional status, indirectly changing which IV therapies are needed—but access decisions still follow vein quality, therapy chemistry, and duration.

Cross-population scenarios

Scenario A — Pediatric long therapy: A toddler needs 14 days of peripheral-compatible IV antibiotics after multiple traumatic PIV failures. Consider midline/PICC evaluation, child-life support, caregiver teaching, and weight-based pump programming—not a plan of daily blind sticks.

Scenario B — Neutropenic fever: An oncology patient with a port develops fever and chills at home after chemo. This is an urgent evaluation pathway: do not delay for “watchful waiting,” protect the port with sterile technique during workup, and follow febrile neutropenia protocols.

Scenario C — Bariatric port access: A patient with deep subcutaneous tissue reports burning during port chemo; blood return is absent. Stop, do not continue the vesicant, reassess needle length/placement, and follow extravasation protocol if infiltration/extravasation is suspected.

High-yield exam traps

• Using adult fluid volumes/rates unchanged in infants
• Ignoring family-centered teaching and child developmental needs
• Giving continuous vesicants through inadequate peripheral access
• Treating neutropenic fever as a minor outpatient nuisance
• Accessing a port with a needle too short for tissue depth
• Repeated blind sticks in bariatric patients instead of ultrasound escalation
• Applying one dosing-weight rule to every drug without pharmacy guidance
• Covering pediatric sites so well that infiltration cannot be inspected