Periprocedural Care in Pediatric Interventional Radiology

Term

37 completed weeks to 41 weeks and 6 days

Premature

Preterm

<37 weeks

Low birth weight

LBW

<2,500 g

Very low birth weight

VLBW

<1,500 g

Extreme low birth weight

ELBW

<1,000 g

Small for gestational age

SGA

BW <10th percentile for GA

Large for gestational age

LGA

BW >90th percentile for GA

Absolute neutrophil count

ANC

White cell count x % that are neutrophils

Severe neutropenia

ANC <0.5 × 10⁹/L

Normal urine output

Infants and young children: 1.5–2 mL/kg/h

Older children and adolescents: 1 mL/kg/h

Estimated body weight (in kg) based on child’s age

Children 1–9 years: (age in years × 2) + 8

Children >10 years: age in years × 3.3

Endotracheal tube size (internal diameter in mm)

Infants <1 year: 3.5 mm (uncuffed)

Children 1–2 years: 4 mm (uncuffed)

Children 2–10 years: 4 + (age/4) (uncuffed)

Children 2–10: 3.5 + (age/4) (cuffed)

Hypothermia

Core temperature< 35 °C

Table 2.2

American Society of Anesthesia—a physical status classification system [6]

ASA 1	Normal healthy patient
ASA 2	A patient with mild systemic disease
ASA 3	A patient with severe systemic disease
ASA 4	A patient with severe systemic disease that is a constant threat to life
ASA 5	A moribund patient who is not expected to survive without the operation
ASA 6	A declared brain-dead patient whose organs are being removed for donor purposes
Prefix “e”	Emergency

Table 2.3

Variations in laboratory values with maturity and age [8]

Test name	Age	Reference values
Activated partial thromboplastin time (APTT)	<3 month	25–35 s
Activated partial thromboplastin time (APTT)	>3 month	23–35 s
INR	<3 month	0.9–1.6
INR	>3 month	0.9–1.1
Hemoglobin	<30 days	140–200 g/L
	1 month	115–180 g/L
	2 months	90–135 g/L
	3–11 months	100–140 g/L
	1–4 years	110–140 g/L
	5–13 years	120–160 g/L
	≥14 years female	120–153 g/L
	≥14 years male	140–175 g/L
Creatinine	≤6 days	19–90 μmol/L
	7–60 days	10–56 μmol/L
	2 months–5 years	<36 μmol/L
	6–9 years	<53 μmol/L
	10–13 years	<79 μmol/L
	≥14 years	<98 μmol/L
Glucose *	<1 year	2.5–5.5 mmol/L
	1–2 years	2.5–5.0 mmol/L
	3–11 years	2.8–6.1 mmol/L
	≥12 years	3.3–6.1 mmol/L

* 1 mmol/L = 18 mg/dL

Table 2.4

Fasting guidelines for GA or sedation (may vary slightly from institution to institution) [8]

Clear fluids	2 h
Breast milk	4 h
Infant formula/cow’s milk	6 h
Solids	8 h

Table 2.5

Example “time-out” checklist

All team members to stop what they are doing and take part in time-out
• Staff present
– Operator(s)
– Anesthesiologist
– Nurse
– Technologist
• Patient name
• Patient identification
• Patient diagnosis/history
• Procedure to be performed
• Procedures by other services to be performed
• Written consent
• Correct site and correct side marked (on patient)
• Patient allergies
• Blood work reviewed
• Last menstrual period/pregnancy test results
• Prophylactic antibiotics
• Correct name on imaging equipment
• Correct orientation on equipment
• Correct side markers in place on equipment
• Radiation protection equipment in place
• Grid in/out
• Any potential adverse events expected
• Equipment for adverse events inside/outside of room
– Crash cart
– Blood warmer
– Blood products
– Warming lights/blankets for neonates
• Equipment for procedure in room
• Any other concerns or comments from any team member in room?

Table 2.6

Age-appropriate normal estimates of weight, endotracheal tube size, and vital signs [8, 24]

Age	Weight (kg) (approx)	HR awake	HR sleeping	RR	BP	ETT size
Birth	3.5	85–205	80–160	30–60	65/40	3.0–3.5
6 months	7.5	110–160	80–160	24–38	85/50	3.5–4.0
1 year	10	90–150	75–160	22–30	90/55	4.0
3 years	14	80–125	60–90	22–30	92/55	4.5
5 years	18	70–115	60–90	20–24	95/58	5.0–5.5
10 years	30–32	60–100	50–90	16–22	100/62	6.0–6.5
12 years	40	60–100	50–90	16–22	106/62	6.5
14 years	45	60–100	50–90	14–20	110/66	6.5–7.0

Table 2.7

Abnormal vital signs in infants and children [8, 24]

Age	Pulse rate/min	Blood pressure (systolic)	Respiratory rate/min
≤3 months	<80 or >200	<60 mmHg	<30 or >60
3–12 months	<80 or >180	<65 mmHg	<24 or >50
1–10 years	<60 or >150	<70 + (2 × age in years)	<22 or >40
• 10 years	<60 or >120	<90 mmHg	<12 or >30

Table 2.8

Commonly used drugs (in alphabetical order)

Name	Dose
Acetaminophen	15 mg/kg PO
Adenosine	0.1 mg/kg/dose IV rapidly
Cefazolin	30 mg/kg/dose IV
Cefoxitin	30 mg/kg/dose IV
Diphenhydramine	1–2 mg/kg/dose IV (anaphylaxis)
Fentanyl	1 μg/kg/dose IV
Flumazenil	10 μg/kg IV over 15 s. Wait 1–3 min. Repeat up to four times
Glucagon	0.02–0.03 mg/kg/dose. Max dose 0.5 mg <20 kg; 1 mg > 20 kg
Heparin	50–100 units/kg to max 5,000 units loading dose
Ketamine	0.25 mg/kg/dose IV
Midazolam	0.05 mg/kg/dose IV; 0.5 mg/kg/dose PO <20 kg; 0.3 mg/kg/dose >20 kg
Morphine	0.05 mg/kg IV dose
Naloxone	0.001–0.01 mg/kg/dose for narcotic reversal in sedated patients
Sucrose	23–32 weeks: up to 0.5 mL PO 2 min prior to procedure
	32–37 weeks: up to 1 mL PO 2 min prior to procedure
	>37 weeks: up to 2 mL PO 2 min prior to procedure
	All infants who are NPO: up to 0.5 mL PO 2 min prior to procedure. Dose may be administered in increments of 2-min intervals for prolonged procedures; divided or repeated to the maximum daily dose. Maximum daily dose: four times in 24 h
Topical anesthetic	Lidocaine (Maxilene) topical anesthetic cream: 2 %—thin layer to skin
Topical anesthetic	Tetracaine (Ametop) 4 % cream/patch—thin layer to skin

Table 2.9

IV Fluid maintenance and bolus guidelines

Maintenance
Weight	Daily volume	Hourly volume
1–10 kg	100 mL/kg/day	4 mL/kg/h
11–20 kg	50 mL/kg/day	2 mL/kg/h
>20 kg	20 mL/kg/day	1 mL/kg/h
Bolus
Hypovolemic shock	20 mL/kg bolus, repeat prn	Give rapidly over 5–10 min
Cardiogenic shock	5–10 mL/kg bolus, repeat prn	Give slowly over 10–20 min

Examples:

Maintenance 23 kg child daily: 1000 mL + 500 mL + 60 mL= 1560 mL/day (~65 mL/h)

Maintenance 23 kg child hourly: 40 mL + 20 mL + 3 mL = 63 mL/h (~1512 mL/day)

Table 2.10

Sodium recommended in routine post-procedure fluids

Fluid	Na⁺ mmol/L	K⁺ mmol/L	Dextrose g/100 mL	Tonicity
D5W (dextrose 5 % in water)	0	0	5	Hypotonic
D10W (dextrose 10 % in water)	0	0	10	Hypotonic
NS (normal saline, 0.9 % NaCl)	154	0	0	Isotonic
½ NS (half normal saline, 0.45 % NaCl)	77	0	0	Half-isotonic
$\frac{2}{3}:\frac{1}{3}\left(\frac{2}{3} \,\,\, \rm dextrose \,\,\, and \,\,\, \frac{1}{3} \,\,\, \rm saline \right)$	45	0	3.33	Hypotonic
Ringers lactate	130	4	0	Isotonic

As outlined in Chap. 1, it is no longer standard of care for interventional radiology (IR) physicians to perform procedures and leave the entire care of the patient to their referring team [1–4]. Increasingly IRs are actively involved in the continuum of patient care, following their patients pre- and post-procedure, either in the capacity of a consulting service or assuming full responsibility with admitting privileges. Many IRs without admitting privileges are actively seeking to obtain such privileges.

Details of specific procedures are dealt with in individual chapters. This chapter will address the following general aspects of periprocedural care:

(a)

Pre-procedure clinical care

(b)

Clinical care during the procedure

(c)

Post-procedure care

Pre-procedure Clinical Care

Patient Assessment

The requirement for pre-procedure assessment depends on the nature of the procedure to be undertaken and ranges from minimal (such as for a gastrostomy tube check) to full IR pre-procedure evaluation, as in a patient with complex vascular malformation seen in a multidisciplinary clinic (see Chap. 1). Much of the IR workload can be considered “service work,” in which case IR provides a valuable supportive service for a large number of patients referred from a variety of specialties, for example, when providing central venous access for surgical and oncologic patients. In other instances, IR provides the definitive therapeutic procedure for a variety of conditions, such as embolization of an arteriovenous malformation. Irrespective of the type of procedure considered, clearly it is important to ensure that the IR procedure requested is indicated and appropriate for that individual patient and to weigh the risk factors or contraindications prior to undertaking the procedure. Making this assessment may necessitate an IR clinic or multidisciplinary clinic visit. At such a visit, a clinical history is taken, physical examination is performed, necessary imaging is reviewed, and any required specialty consultation, imaging, or blood work is organized.

Evaluation of Imaging

Careful evaluation of available imaging is important in order to confirm that the procedure, for example, a biopsy or abscess drainage, is technically possible and clinically appropriate. If there is any uncertainty about access, choice of modality to be used, or suitability for the planned procedure, this can be resolved by pre-procedure “mapping” imaging, ideally performed by an interventionalist, with the very specific and focused questions below in mind (different than those asked in a standard diagnostic imaging exam):

(a)

Is the lesion well visualized with this imaging modality, or is another modality required?

(b)

Can the lesion be safely accessed percutaneously, avoiding interposed vessels and other relevant structures, such as bowel or pleura?

(c)

What are the risks and benefits of different trajectories or angles?

(d)

What level of sedation/anesthesia is required for this patient for this procedure?

Mapping imaging may involve ultrasound, fluoroscopy, CT, or a combination of imaging modalities (e.g., combination of US and fluoroscopy mapping to assess the feasibility of placing a gastrostomy tube in an infant with distorted abdominal anatomy post diaphragmatic hernia repair). Mapping will determine the imaging required (e.g., should US or CT be used to access a small peripheral pulmonary nodule for biopsy) [5]. Time taken for pre-procedural mapping is time well spent, as it improves the accuracy of procedure planning, decreases the need for last-minute changes to the plan, enables the case to be scheduled with the most suitable equipment (e.g., CT scanner if needed), and avoids the situation where the patient must be moved during a case or, even, the procedure canceled. In addition, an appointment for mapping gives the parents and child an opportunity to visit the IR department and meet members of the team. The results of the mapping imaging are shared with the referring physician and the family, and a plan to proceed (or not proceed) is reached. This visit also provides an opportunity to obtain informed consent well in advance of the procedure, which is preferable to obtaining written consent immediately prior to the procedure, as the more relaxed setting allows a more adequate consent process for the family.

Consultations

Specialty consultation may need to be arranged prior to a procedure. Most commonly this involves an anesthesia consultation, usually indicated in children with known airway difficulties, complex cardiopulmonary problems, or American Society of Anesthesiology (ASA) Class 4 or 5 (Table 2.2) [6]. Additional investigations if required by the anesthesiologist are arranged in advance of the procedure (e.g., in an acute setting, an ECG, cardiology consultation, and echocardiography in a patient with a large anterior mediastinal mass pre-biopsy to evaluate pulmonary artery and venous flows, vascular compression, as well as the cardiac ejection fraction) [7]. Other examples include an ophthalmology consultation to evaluate eyes/vision prior to management of a periorbital vascular malformation or a cardiology consult in a child with cardiac symptoms or signs.