Kiddie-Caudals Caudal Epidural Analgesia in Everyday Pediatric Practice Sabine Kost-Byerly, MD, FAAP Associate Professor and Director, Pediatric Pain Management Department of Anesthesiology/Critical Care Medicine Johns Hopkins University, Baltimore, Maryland

Objectives Upon completion of this lecture, the attendee will be able to: Appreciate the technical aspects of caudal analgesia Select appropriate local anesthetic solutions for caudal analgesia Recognize and manage complications of caudal epidural analgesia

Disclosures I have no relevant financial relationships with manufacturers of any commercial products or providers of commercial services discussed in these slides.

Caudal Epidural Analgesia caudal lumbar thoracic Advantages: Easy to perform High success rate Usually no hemodynamic changes

Caudal Epidural - Indications Surgeries: – Urologic – Orthopedic – general Locations: – lower abdomen – lower extremities Regional Alternatives to consider: – Peripheral nerve block – Truncal block – Extremity blocks

Demographics for 13,725 patients in the Pediatric Regional Anesthesia Network (PRAN) database. Anesth Analg 2012;115:

Single Injection Caudal Placement by Age by age. Polaner D M et al. Anesth Analg 2012;115:

Caudal Block in Children: Technique Position: lateral decubitus, knees flexed Landmarks: sacral cornuea at sacral hiatus Needle position: 45°-60° angle to coronal plane “pop” : piercing the sacro-coccygeal membrane Reduce angle to 10°-20° and advance a few mm

Kiddie- Caudal - Single Injection Needle: – 22-g needle – 22 – g angiocath (risk: epidermal-cell graft tumor – but: no reports) – 22-g short-beveled, styletted needle

Caudal Block Identification of Landmarks Post sup iliac spines Sacral cornu

Caudal Block Placement of Cannula

Caudal Block in Children No Touch TechniqueDistance to Caudal Space

Location, location…is your needle where it should be? Clinical Assessment The “pop” – the sacrococcygeal membrane – No visible/palpable subcutaneous injection The whoosh (air) test – Risk: patchy block, venous air embolus The swoosh (NS) test – Risk: dilution of LA Technical Aides Ultrasound – Experience, assistant Tiffterer l et al. Br JAnaesth 2012;108;670-4

Testdose – sometimes the caudal IV is the easiest… Aspiration Avoid patient simulation Dose – Epinephrine 0.5 mcg/kg in 0.1 mL/kg of LA Continuous ECG monitoring – T-wave changes >25% increase – HR increases – BP increases Inject rest of LA dose slowly in increments

Results: 742 pediatric epidural blocks 644 caudal 284 single caudal injections 42 (5.6%) Intravascular injection 3.8% with single caudal injections Detection: 6 immediate aspiration of blood 30 HR increases >10 bpm 25 T-wave amplitude increases 29 ECG changes in T-wave or rhythm

Amide Local Anesthetics Lidocaine Bupivacaine Ropivacaine Sodium channel blockers Protein binding – 65% (lido.) – 95% (bupiv., ropiv.) – Α1 acid glycoproteine (AAA), albumin Neonate low AAA: ↑ free fraction of LA Metabolism: – cytochrome P450 system CYP3A4 for bupivacaine and lidocaine – Bupiv. at 1 mo 1/3 of adult, at 6 mo 2/3 CYP1A2 for ropivacaine – Max for ropiv not reached till age 5

Choice of LA Bupivacaine: Slower onset, longer duration Cardiac toxicity>CNS toxicity Single dose – 1 mL/kg of 0.25% bupivacaine – max <2.5 mg/kg “Ideal”: concentration – % comparable duration of analgesia, less motor block Ropivacaine: Duration similar Less motor block at lower concentrations Less toxicity Single dose – 1 mL/kg 0.2% ropivacaine

Choice of LA Lidocaine: Short onset, medium duration CNS toxicity>cardiac toxicity Single dose – up to 5-7 mg/kg Chloroprocaine: Short onset, short duration Advantageous toxicity profile Single dose – up to 14 mg/kg - or more

Epidural Additives – improved and prolonged analgesia The Common Opioids Inpatients only – Fentanyl2 mc/kg – Morphine mcg/kg Pruritis, emesis, respiratory depression Clonidine Alpha -2-agonist Single dose 1-2 mcg/kg – Risk: bradycardia, apnea in young infants – Increasing sedation with higher doses The Rare Continued concerns of safety for neuroaxial use: – preservative, ph, neurotoxicity Ketamine 0.25 – 1 mg/kg Neostigmine 2 mcg/kg – Emesis common Midazolam 50 mcg/kg Dexmedetomidine1- 2mcg/kg – Analgesia similar to clonidine Tramadol 2 mg/kg

Caudal single Injection – Volume Correlation between cranial level and volume Exact prediction of level not possible Volumes < 1 ml/kg not likely to reach higher than L2 Speed of injection does not matter Brenner L et al. Br J Anaeth 2011; 107:229-35; Tiffterer l et al. Br JAnaesth 2012;108;670-4 Thomas L< et al. Paediatr Anaesth 2010;11: Volume for injection: – 0.5 ml/kg for perineal surgery – 1.0 ml/kg for lower abdominal surgery – 1.25 ml/kg for upper abdominal surgery

Volume versus Concentration RCT Bupivacaine with epi O.8 mL/kg 0.25% B vs 1 ml/kg 0.2 % B Lower GA requirement with higher volume Maybe better postop analgesia with higher volume Vergehese ST et al. Anesth Analg 2002;95:

Complications Common: Pruritis Nausea & emesis Sedation Urinary retention Rare, but serious Systemic toxicity – Inadvertent IV injection Overdose – Inadvertent IT injection Infection/Hematoma/Neuro pathy

Risk of Systemic LA Toxicity 10,098 epidurals – 8493 caudals – 7 with transient ECG changes – no treatment Pediatric Anesthesia 2010;20:

ASRA Recommendations – Prevention of LAST Neal JM et al. Reg Anesth Pain Med 2010;35: Lowest effective dose of local anesthetic Incremental injection of local anesthetics Aspirate the needle or catheter before each injection Use of an intravascular marker (epinephrine) is recommended. Ultrasound guidance may reduce frequency of intravascular injection – Effectiveness remains to be determined

ASRA - recommended LAST -Management ABC’s Seizures: – Benzodiazepines, small dose propofol – avoid large dose propofol for risk of CV compromise – Succhinylcholine or other NDMB, small doses to minimize acidosis and hypoxemia Cardiac arrest – ACLS, but epinephrine - small initial doses (10mcg to 100 mcg boluses in the adult) preferred Vasopressin not recommended Calcium channel blockers and A-adrenergic receptor blockers – avoid Amiodorone for ventricular arrhythmias, treatment with local anesthetics (lidocaine or procainamide) not recommended – Lipid emulsion therapy -Consider administering at the first signs of LAST, after airway management 1.5 mL/kg 20% lipid emulsion bolus 0.25 mL/kg per minute of infusion, continued for at least 10 mins after circulatory stability is attained Consider rebolus if circulatory stability is not attained and increase infusion to 0.5 mL/kg per minute (up to 10 mL/kg lipid emulsion within 30 mins) – Propofol is not a substitute for lipid emulsion – Cardiopulmonary bypass failure to respond to lipid emulsion and vasopressor therapy notify the closest facility capable of providing it when CV compromise is first identified during an episode of LAST. Neal JM et al. Reg Anesth Pain Med 2010;35: Lipid emulsion therapy Consider administering at the first signs of LAST, after airway management 1.5 mL/kg 20% lipid emulsion bolus 0.25 mL/kg per minute of infusion, continued for at least 10 mins after circulatory stability is attained Consider rebolus if circulatory stability is not attained and increase infusion to 0.5 mL/kg per minute (up to 10 mL/kg lipid emulsion within 30 mins) Propofol is not a substitute for lipid emulsion

Intralipid for LA-induced Cardiotoxicity in infants 2-day-old 3.2 kg term infant – Caudal, 1 mL/kg 0.25% bupivacaine, with US guidance and confirmation – VT, cardiovascular collapse – 20% Intralipid 1 ml/kg – recoveryLin EP et al. Pediatric Anesthesia 2010; 20: day-old, 4.96 kg infant – Caudal, 0.9 mL/kg 0.25% bupivacaine – Tachycardia, T-wave inversion hypotension – Epinephrine 2 mcg/kg x2, 20mL 55 albumin – no change – 20% Intralipid 2 ml/kg – recoveryShah S et al. J Anesth 2009; 23:430-41

TDDPVPABFBCRNOtherTotal Events Total Procedures % Caudal (97%) 2.9 Lumbar Thoracic Sub- arachnoid // Total TD:positive test dose DP:dural puncture VP:vascular puncture AB:abandoned block FB:failed block C:cardiovascular R:respiratory N:neurological NO significant complications in caudal group! 93% of caudal blocks placed without technical aids or imaging 3% with ultrasound guidance Adverse Events and Complications

Summary Caudal anesthesia and analgesia is: An easy technique to supplement general anesthesia Requires few resources Easy to learn Provides several hours of postoperative analgesia Is overall a very safe analgesic technique

Thank You Questions?