Sir, Chromosome 9p22 deletion is a rare genetic syndrome, with deletion on the short arm of chromosome 9 at the 9p22 region. This syndrome is associated with varied phenotypic features, including mental retardation, trigonocephaly, upwards slanting palpebral fissures, facial dysmorphism, hypotonia, cardiac defects, hernias, abnormal genitalia and scoliosis.[1] We report the anaesthetic management of one such infant for inguinal herniotomy. A 2.6 kg, 1-month-old term male infant [Figure 1], born out of non-consanguineous marriage, delivered by elective caesarean section, was admitted for right inguinal herniotomy. Congenital central hypothyroidism was diagnosed at birth (free T4 0.62 ng/dl, total T4 4.8 μg/dl, thyroid stimulating hormone [TSH] 2.49 mIU/ml (normal range in newborn-free T4 1.4–2.3 ng/dl, total T4 11–24 μg/dl, TSH 1–10 mIU/ml) by a paediatric endocrinologist and daily treatment with tablet thyroxine 25 μg was initiated. Oligohydramnios was the only remarkable feature in the antenatal period. On examination, infant had profound hypotonia, hirsute forehead with arched eyebrows, small palpebral fissures, micrognathia, high arched palate, small ears, widely spaced nipples, left post-axial polydactyly, long fifth finger with extra crease, and paraumbilical, right inguinal hernia. Systolic murmur grade 2/6 was heard along the left sternal border. Echocardiogram revealed fenestrated secondary atrial septal defect with an interatrial septal aneurysm, 3 mm patent ductus arteriosus with left to right shunt and good left ventricular function. Rest of the systemic examination and blood reports were normal. Genetic analysis revealed chromosome 9p22 deletion. The infant was electively accepted for surgery under American Society of Anesthesiologists III with high-risk consent, in view of congenital heart disease and central hypothyroidism. Thyroid status was optimised (TSH 0.13 mIU/ml, T4 15.3 μg/dl). Difficult airway was considered due to the presence of retrognathia, micrognathia, high arched palate with hypothyroidism. Figure 1 Infant with chromosome 9p22 deletion syndrome Standard nil per os (NPO) guidelines for breastfeeding were followed. A 22 gauge intravenous cannula was secured in the ward and balanced salt solution at maintenance rate was started during NPO hours. The infant was taken for surgery as the first case of the day, connected to standard monitors with difficult airway cart ready. After pre-oxygenation, propofol 6 mg intravenous (IV), in slow titrated doses ensuring maintenance of spontaneous ventilation, fentanyl 3 μg, dexamethasone 1.5 mg (IV), as prophylaxis for post-operative nausea and vomiting was administered. A nasogastric tube was placed and aspiration performed. After adequate depth of anaesthesia was ensured by lack of response to jaw thrust, airway was secured with size one i gel®. Ventilation was adequate with bilateral chest expansion, absent gastric inflation and oropharyngeal leak pressure of 18 cm of water. Anaesthesia was maintained with total IV anaesthesia (TIVA) with propofol 15 mg/h infusion. Spontaneous/assisted ventilation was maintained with oxygen and air in 50:50 ratio ensuring normocarbia. Caudal analgesia with 2.5 ml of 0.125% bupivacaine was administered. Propofol infusion was decreased to 9 mg/h. Calculated, judicious administration of warm intravenous fluids was done with infusion pump. Vitals were within normal range during the 50 min surgery. At the end of surgery, propofol infusion was discontinued, i gel® was removed and the infant shifted to post-anaesthesia care unit when adequate ventilation and stable haemodynamics were confirmed. The post-operative course was uneventful. Chromosome 9p22 deletion presents with multiple anaesthetic challenges including: (1) difficult airway, (2) congenital heart disease, (3) congenital hypothyroidism, (4) hypotonia, and (5) anaesthetic implications unique to an infant. As literature is minimal on this syndrome, anaesthetic implications had to be scrutinised, and protocol formulated. Spinal anaesthesia has the advantage of providing adequate anaesthesia with reduced risk of post-operative apnoea but there is a risk of high/total spinal block with apnoea and bradycardia. In the presence of multiple anaesthetic challenges, elective securing of the airway and cardiac stability with new, short-acting drugs with the administration of general anaesthesia was preferred. Airway management in infants with facial dysmorphism may be difficult.[2] Hypothyroidism may also contribute to a difficult airway due to associated macroglossia, facial oedema and large head. In our case, the airway was adequately secured with i gel®.[3] Intraoperatively, inhalational anaesthetics were avoided due to the presence of hypotonia suggestive of undiagnosed muscular dystrophy and risk of malignant hyperthermia and rhabdomyolysis.[4] Potentiation of anaesthetic action causing circulatory and respiratory depression was anticipated due to underlying hypothyroidism and hypotonia. Considering these factors, propofol in titrated doses was preferred due to its lack of major systemic side effects and rapid recovery.[4,5] Caudal anaesthesia decreases the anaesthetic requirement by providing analgesia without Cardiorespiratory depression.[6] Thus, we could successfully manage the infant with chromosome 9p22 deletion for inguinal herniotomy with i gel® and TIVA with propofol infusion and caudal epidural analgesia. In syndromic infants, all the comorbidities should be individually evaluated and appropriate measures taken for a smooth perioperative course.
Read full abstract