Inguinal Hernia of Premature Infants

Brief History 2 months old male infant G3P1AA2 GA: 28 weeks+6 Birth body weight: 1302gm

Brief History Maternal APH, PPROM, placental abruptio C/S on 2004/11/11 Apgar score: 7→8

Brief History Frequent apnea episodes on 11/13-14 and aminophylline was given Abscess and osteomyelitis in 2005/12 Pre-op: BW: 2644gm Herniorraphy for umbilical and right inguinal hernia on 2005/1/21

Aminophylin Atropine 0.1mg Sevoflurane

Discussion 1. When should repair of inguinal hernia be done? 2. Anesthetic risks for surgery of premature infants 3. What kind of anesthetic technique is better?

Inguinal Hernia in Prematurity Incidence: 14-30%(children: 2%) Higher incidence of incarceration in infants Hernia repair when ready for discharge has be accepted Pediatr Surg Int (1999) 15: 36-39

Inguinal Hernia in Prematurity VLBW infants had a longer operation time and a longer waiting period Preoperative medical complication: RDS, sepsis, and cardiac failure→ considered to delay surgery The shorting waiting group had shorter operation time No correlation between operation time and body weight at surgery

Inguinal Hernia in Prematurity For long waits for surgery in VLBW infants: hernia sac may grow large and thick, and fibrous adhesions may develop Difficult surgical repair and the risk of gonadal ischemia may be increased

The Most Common Medical Problems in Prematurity Respiratory distress syndrome (RDS) Apnea of prematurity Anemia of prematurity Patent ductus arteriosus Intraventricular hemorrhage

The Formerly Premature Infant Bronchopulmonary dysplasia (BPD): 1. the sequelae of RDS 2. the leading cause of chronic lung disease during infancy 3. periodic episodes of bronchospasm, especially during URI

Anesthetic Management of Infants with BPD Optimization of respiratory status Deep extubation to avoid bronchospasm Regional analgesia in abdominal procedures for pain control

Laryngeal and Tracheal Injury Prolonged intubation and mechanical ventilation Subglottic stenosis Smaller ET tube when intubation Stridor following extubation

Postoperative Apnea May be accompanied by bradycardia Probably related to the effects of general anesthetic agents on the immature respiratory control center Low gestational age, low postconceptional age, preoperative apnea of prematurity

General VS Spinal Anesthesia GA<36wks and post-conceptual age (PCA)<46wks Exclude preexisting cardiac, neuromuscular or metabolic diseases Preoperative hemoglobin and a history of preexisting abnormal respiratory function British Journal of Anaesthesia 86 (3): 366-71 (2001)

General Anesthesia (Group 1) Induction: 2 MAC sevoflurane and atracurium 0.5 mg/kg Maintenance: 0.5-1.0 MAC sevoflurane until completion of skin closure Reversed with neostigmine 50 μg/kg and glycopyrrolate 10 μg/kg Caudal epidural injection with 0.25% bupivacaine 2 mg/kg

Spinal Anesthesia (Group 2) 0.5% bupivacaine 1 mg/kg Caudal epidural injection with 0.25% bupivacaine 2 mg/kg

Results Spinal anesthesia was attempted unsuccessfully in four patients in group 2 5 patients in group 1 demonstrated an excess number of episodes of postoperative cardiopulmonary complications 3 patients had preexisting abnormal respiratory function and accounted for 80% of the episodes

Prevention of Postoperative Apnea Performing a regional anesthetic instead of a general anesthetic Perioperative administration of caffeine Selection of general anesthetic agents or opoids that are characterized by their limited duration of action

Regional Anesthesia Lower incidence (not complete absence) of postoperative apnea The risk is similar to general anesthesia hen adding systemic sedatives Potentially stressful for the infant and associated with a clinically significant failure rate

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