Clinical Guidance. Neonatal Manual Chapter 4: Neonatal Surgery

Transcription

1 Clinical Guidance Neonatal Manual Chapter 4: Neonatal Surgery Summary This manual contains clinical guidelines developed by the Neonatal Unit multidisciplinary team over recent years. This chapter contains guidelines on neonatal surgical conditions. It is linked to and should be used in conjunction with the completed neonatal manual details of which are contained in the introductory chapters. Document Detail Document Type Clinical Guideline Document name Neonatal Manual Chapter 4: Neonatal Surgery Document location GTi Clinical Guidance Database Version 2.0 Effective from November 2011 Review date November 2013 Owner Clinical Lead, Children s Services Author Timothy Watts, Consultant Neonatologist Ali Keshtgar, Consultant Paediatric Surgeon Approved by, date Neonatal Clinical Governance Group, November 2011 Superseded documents Neonatal Manual Chapter 4: Neonatal Surgery v1.0 Related documents Neonatal Manual Chapters 1-15, Neonatal nursing guidelines: general pre-operative care, general immediate post-operative care, feeding of neonates on the Neonatal Unit following surgery Keywords Neonatal, Neonatology, Neonatal Unit, Newborn, NNU, NICU, SCBU, pre-operative, post-operative, crossmatch, NEC, exomphalos, diaphragmatic hernia, oesophageal atresia, tracheo-oesophageal fistula, gastroschisis, Hirschsprung s, rectal washout, rectal biopsy, imperforate anus, ano-rectal, bilious vomiting Relevant external law, regulation, standards Change History Date Change details, since approval Approved by

2 4. Gastro-intestinal system Page 4.1 Pre-operative preparation Necrotising enterocolitis Congenital diaphragmatic hernia Oesophageal atresia / tracheo-oesophageal fistula Exomphalos (omphalocoele) Gastroschisis Ano-rectal anomalies Delayed passage of meconium Hirschsprung s disease - including Rectal Suction Biopsy Rectal washout Neonatal presentation with bilious vomiting 23 This chapter should be used in conjunction with the main guideline and other chapters as appropriate. Page 2 of 23

3 4.1 PERI-OPERATIVE CARE Cross match guidance Ensure 2 samples for blood group have been sent Refer to Paediatric Maximum Surgical Blood Ordering Schedule (MSBOS) in Clinical Guidance on the intranet Babies <1 month old with congenital heart disease should have irradiated blood (this does not include PDA ligation) Generally guided by surgeons, but may use following guidelines. Cardiac surgery - For bypass cardiac surgery 2 adults units of packed red blood cells and 1 adult dose of platelets - For other cardiac surgery (including interventional catheter) 1 adults unit of packed red blood cells - PDA ligation 1 paediatric unit of packed red blood cells General surgery - Hernia repair - group and save, provided Hb is normal - Most significant general neonatal surgery will require cross match of 1 adult unit. Some operations will only require group & save. Check Paediatric MSBOS document. ENT - Usually cross match only required, but liaise with surgeons Pre-op management Check FBC and Neonatal profile on the day before (and on the day of the surgery for major operations or if baby unstable). Coagulation profile should be checked before any major surgery or if clotting abnormalities are expected. Ensure that baby has received vitamin K if surgery necessary in first few days of life. Review on the day to check that baby is fit and stable for the surgery, discuss with senior colleagues and anaesthetist if any concerns. Ensure that there is secure IV access and start 10% Dextrose + additives at the time of the 1 st omitted feed - If formula fed, last feed 6 hours prior to surgery - If breast fed, last feed 4 hours prior to surgery Ensure that the operating surgeon has obtained written informed consent Consider whether there is significant potential for intra-operative deterioration and whether preparation of infusions such as inotropes pre-operatively may be appropriate Babies with cardiac abnormalities may require Cardiology review prior to any surgery. Babies with any significant congenital abnormalities should be considered for echocardiography before surgery. Page 3 of 23

4 Liaise with NICU regarding cot availability in babies likely to return from theatre ventilated Ensure completion of any required pre-operative documentation Vascular access Appropriate vascular access varies from case to case. For major surgery, it should be discussed with consultant on NICU and the anaesthetist. Refer to Guidelines for lines for neonates requiring major surgery on the intranet. A single well-functioning peripheral line may be adequate for minor procedures (eg hernia repair, MRI scan, PDA ligation, single bowel loop obstruction, Broviac insertion) For more major surgery, ensure at least 2 IV lines, one of which may be central, particularly if inotropic requirement is anticipated An arterial line should be sited if possible prior to any major operation Post-op management Ensure notes regarding transfer to and from theatre are completed, including transfer documentation. Review baby s ventilatory & fluid requirements and document an examination. Post-op bloods: neonatal profile, full blood count +/- coagulation as required Review prescription anaesthetic chart and prescription chart for intra-operative medications, including antibiotics and pain relief. Chart appropriate analgesia and sedation. Reduce maintenance fluids to approximately two thirds previous requirement for at least 24 hours post-op as there is often SIADH. Further fluid restriction may be necessary and should be carefully evaluated at least once daily. Read the surgeons operative notes carefully and follow instructions as indicated. Page 4 of 23

5 4.2 NECROTISING ENTEROCOLITIS Clinical staging ( Bell staging ) Stage 1 suspected NEC GI symptoms/signs: mild abdominal distension, tenderness, poor feeding, vomiting, increased gastric aspirates (especially bilious), faecal occult blood (no anal fissure) Systemic signs: temperature instability, lethargy, apnoea Abdo. XR: dilated loops, thickened bowel wall but no pneumatosis Stage 2 confirmed NEC Any features of stage 1 disease, plus: persistent occult or frank GI bleeding, marked abdominal distension, abdominal wall oedema/discolouration abdominal XR: gross intestinal distension, bowel wall thickening, unchanging bowel loops, intramural gas, portal vein gas features of NEC at laparotomy Stage 3 advanced NEC Any features of stage 1 or 2 disease, plus: shock, severe sepsis or gross GI bleeding abdo. XR shows evidence of perforation (or confirmed at laparotomy) Investigations Abdo. XR - ask for AP (Consider a lateral with LIVER UPPERMOST if there is doubt about perforation) - serial x-rays can be helpful ( 6-12 hourly in first incidence) - look for thickened bowel wall, intramural gas (pneumatosis intestinalis), free air ( football sign or (rarely in neonates) air under diaphragm in AP films or uppermost above liver in left down lateral, air in portal system (sign of severe illness), large distended loops of bowel which do not change from film to film (may suggest gangrenous bowel). Abdo u/s - is useful to detect pneumotosis, free peritoneal fluid, air in portal vein or biliary tree and for assessment of focal signs (e.g. mass) FBC & film - may show leucocytosis or neutropenia - left shift & toxic granulations - thrombocytopenia - haemolysis clotting screen biochemistry profile including CRP blood gas/acid base balance/lactate check on presentation and then subsequently as needed blood cultures stool for M,C+S (including C. difficile) and virology (infective causes of NEC are rare but may be implicated in outbreaks) stool for occult blood (can be tested on unit using FOB card, although this is not usually done routinely as this method is oversensitive and is usually positive if the baby has received oral iron) consider checking T-cryptantigen status Initial medical management nil by mouth large bore nasogastric tube with free drainage Page 5 of 23

6 IV fluids - clear fluids initially then TPN once stable biochemically IV antibiotics - usually amoxicillin, gentamicin and metronidazole frequent reassessment by clinical examination +/- abdo. XR contact Paediatric Surgeons early adequate analgesia with morphine IVI low threshold for intubation and ventilation. Avoid nasal CPAP. Subsequent medical management 7-14 days NBM & IV fluids from time of resolution of symptoms/signs. This may vary depending on the certainty of diagnosis trophic feeds (i.e. 1mL/kg/hr) for hours initially and then increase by no more than 1mL/kg/hr 24 hourly until fully enterally fed use EBM if available. If EBM unavailable use donor EBM or Peptijunior until full feeds tolerated for one week then Nutriprem 1, Nutriprem 2, or Aptamil as appropriate for weight (see separate enteral feeding protocol) graded in over 4 days. consider upper or lower GI contrast studies if stricture(s) are suspected in babies who have had confirmed or suspected NEC. Always do lower GI contrast study before upper if both indicated. Surgical in acute phase, may be considered if medical management is failing, or if there is perforation, abdominal mass, portal venous gas, fixed loop of bowel on serial abdominal XR suggestive of gangrenous bowel late surgery may be considered due to stricture formation or abscess / inflammatory mass if surgery planned, consent should be obtained (by the Paediatric Surgeon) for laparotomy +/- resection of bowel +/- ileostomy +/- insertion of peritoneal drain cross match 2 adult units of blood prior to surgery and any other blood products as needed Page 6 of 23

7 4.3 CONGENITAL DIAPHRAGMATIC HERNIA (CDH) In this condition, the pulmonary vasculature of the hypoplastic lungs is hyper-reactive to hypoxia, acidosis and stress; anything causing these will exacerbate pulmonary vasoconstriction, pulmonary hypertension and right-to-left shunting. The aim of pre and postoperative management of infants with CDH is to minimise hypoxia, acidosis and stress, and to maintain oxygenation and pulmonary vasodilatation. In addition, it is essential to prevent air entering the gut, by early intubation and avoiding mask ventilation, thereby avoiding external pressure on the already compromised lung. Anatomy and pathophysiology 85-90% occur as a defect of the posterolateral segment (Bochdalek hernia). 80% are left-sided and the hemithorax contains herniated bowel, spleen, stomach and often part of the left lobe of the liver. The bowel is often malrotated. Right-sided hernias usually contain the right lobe of the liver. In virtually all cases, there is a degree of lung hypoplasia there may be just a small amount of lung tissue on the side of the hernia and the contralateral side is also hypoplastic. PPHN is common and the pulmonary vasculature is hyper-responsive to hypoxia, acidosis and hypercarbia. Up to 50% of affected fetuses (30% of liveborn) will have other associated anomalies e.g. chromosomal. Anterior or Morgagni diaphragmatic hernia is much less common and usually right sided. Clinical features Usually diagnosed on routine antenatal ultrasound anomaly scan May present antenatally with polyhydramnios Postnatal presentation is of increasing respiratory distress and cyanosis soon after birth. The abdomen is typically scaphoid, heart sounds are on right side of chest with absence of left sided breath sounds which may be replaced with bowel sounds. CXR: air-filled loops of bowel in the hemithorax with mediastinal displacement. Differential diagnosis: Congenital cystic adenomatoid malformation of the lung (in this the loops of bowel are below the diaphragm if the diagnosis is still uncertain, repeat CXR with contrast injected into NG tube). Planning for Delivery Inform the attending neonatal consultant who will plan to attend the delivery In addition assemble a team of at least 3 individuals A. Person responsible for intubation. This should be a doctor experienced in intubation, preferably who has previously managed the resuscitation of an infant with CDH. B. This individual is responsible for establishing venous access. C. An experienced senior neonatal nurse Check the resuscitation box for necessary equipment Prepare syringes with doses of Pancuronium (100 micrograms/kg) and Fentanyl (5 micrograms/kg) and 0.9% sodium chloride flushes Ensure INNOVENT delivery system is available for providing inhaled nitric oxide therapy on admission to NNU Within normal hours, inform Paediatric Surgery team prior to birth if there has been antenatal diagnosis. Labour Ward resuscitation Intubate and commence PPV immediately after birth. IPPV with bag and mask should be avoided Page 7 of 23

8 An 8F nasogastric tube should be passed and aspirated to decompress the gut and then keep on free drainage. Establish IV access and give early sedation and muscle relaxation once the airway is secure. Calculate the dose according to an estimated weight. Transfer to NICU once condition stabilised NICU management Inform Paediatric Surgery team of birth. Maintain free drainage for NGT, NBM and maintenance IV fluids. Optimise sedation and paralysis, which should have been initiated previously, as above. Arterial and central venous access are essential and therefore should be obtained by an experienced member of staff Consider starting HFOV early using the Sensormedics Oscillator if there are early signs of severe respiratory failure. PPHN is common see separate protocol and consider ino early. Maintain ph and PCO 2 within the normal range. (i.e. ph and PCO 2 4-6kPa) and treat metabolic acidosis as per separate protocol. Consider exogenous surfactant therapy if the baby has a persistent high FiO 2 despite a high mean airway pressure and inhaled nitric oxide. ECMO: the role of ECMO is controversial in CDH. A North American study as well as the UK Collaborative ECMO Trial failed to demonstrate an improved outcome with ECMO. However, if the oxygenation index is >40, the case should be discussed with an ECMO centre (see separate protocol). It may take several days to achieve a stable baby on optimal pharmacological and ventilatory support, but there is good evidence to suggest that pre-operative stabilisation considerably decreases mortality. Keep the Paediatric Surgical team updated on progress. If possible the baby should be switched to conventional ventilation for several hours prior to the operation. If this is not achievable, it is possible with appropriate planning, to operate whilst the baby is still on HFOV. In infants with co-existing complex congenital heart disease outcome is guarded. In those with mixed circulations oxygen saturation levels around 80% may be adequate. These infants will need regular monitoring of their lactate levels as a measure of the adequacy of cellular oxygenation. Surgery Adequate pre-operative stabilisation decreases mortality. Once the ventilatory requirements have reduced and the baby stabilised, surgery can be planned. This would generally be considered once the baby is on conventional ventilation (preferably for at least 48 hours); and preferably off ino and inotropes. The hernia is reduced and the defect is repaired. Often a Ladd s operation is also performed for malrotation (in up to 40% of cases). Post operative management Hyper-reactivity of the pulmonary bed continues in the post-operative period, so preventative measures are continued and weaning from drugs and ventilation should be cautious. In an effort to reduce the TPG (Trans Pulmonary Gradient: an index of the pressure differential across the alveolar wall) a high ventilatory rate and small tidal volumes are preferable or the baby can be put back on HFOV. The pleural cavity on the side of the defect is inevitably air-filled in the early post-operative period. The air is then absorbed and the mediastinum may then shift towards the operated side, resulting in a fixed over-expansion of the contralateral lung. This resolves over several days because the operated side fills with plasma which tends to centre the mediastinum. Page 8 of 23

9 If the fluid accumulation is excessive, the mediastinum may be pushed towards the non-operated side, compressing the normal lung. In both situations of mediastinal shift, kinking of the great vessels may occur and result in acute cardiac failure. There is inevitable third space loss of the plasma that will accumulate in the chest, and may need replacement in the first few post-operative days. Current practice tends to be away from the use of a chest drain. If an intra-operative chest drain is in-situ, it does not need to be routinely put under suction unless instructed by the surgeon. Antibiotic prophylaxis is necessary only if a chest drain is in-situ or there are concerns about infection related to the use of a patch to close the defect. Outcome There remains an overall risk of mortality of 40% Poor prognostic indicators: - Polyhydramnios - Associated cardiac or other severe congenital abnormalities - Prematurity and low birthweight - Low Apgar scores - Poor blood gases / ventilation indices Early presentation (N.B. normal antenatal u/s scans followed by presentation after 24 hours of birth is associated with close to 100% survival). Page 9 of 23

10 4.4 OESOPHAGEAL ATRESIA / TRACHEO OESOPHAGEAL FISTULA Definition of terms NG - nasogastric tube TOF - tracheo oesophageal fistula TAT - trans-anastomotic tube Presentation Antenatal - polyhydramnios +/- absent stomach bubble Postnatal - NG tube can not be passed into stomach during initial resuscitation / assessment (x-ray if in doubt will show NG tube coiled in upper pouch) - Excessive oral / upper airway secretions ("frothy") - Choking or cyanosis following feeds - Recurrent pneumonia/ aspiration Associated anomalies VACTERL association (vertebral / anorectal /cardiac / tracheo-esophageal / renal / limb): ~30-50% of babies with oesophageal atresia & TOF have this CHARGE association (coloboma / heart / atresia choanae / restricted growth / genital hypoplasia / ear) duodenal atresia ( double bubble only seen if TOF present with oesophageal atresia) diaphragmatic hernia more common in karyotype abnormalities (trisomy 21 & 18, 22q deletion) Diagnosis Oesophageal atresia - chest & abdominal X-ray with NG or Replogle tube in situ - ~85% have a blind ending proximal oesophageal pouch with a distal TOF - ~10% have no TOF - ~5% have a TOF connected to the proximal oesphageal pouch +/- a distal TOF TOF - isolated TOF (H-type) much rarer than with oesophageal atresia - Waterstone s test - pass NG tube into the stomach and place free end under water slowly pull tube back and if fistula is present you may see bubbles appearing - Tube oesophogram NG tube is inserted and withdrawn under x-ray screening whilst simultaneously injecting water-soluble contrast medium. If fistula is present contrast will be seen to leak over into airways and lungs. (This procedure is not always well tolerated and a doctor should accompany the baby to the department with resuscitation equipment). Management After a thorough initial clinical examination, request karyotype (even if no other dysmorphic features), echocardiogram, renal and cranial ultrasound scan and X-ray of whole spine in all babies with oesophageal atresia +/- TOF. Request an ophthalmological opinion if CHARGE suspected. Oesophageal atresia - attempt to introduce a NG tube into stomach on first suspicion - when diagnosis confirmed place a Replogle tube (10F smaller in VLBW baby) and apply appropriate suction sufficient to constantly drain pouch (refer to Replogle nursing guideline). Tube must be placed as far as possible and kept in that position. Flush with 0.9% saline Page 10 of 23

11 - NBM / IV fluids or TPN - baby s head should be elevated - surgical management (not an emergency can wait for working hours) Divide TOF and repair trachea attempt to rejoin oesophagus if primary closure not possible then gastrostomy feeding tube inserted with plan to wait for 8-12 weeks to allow growth if atretic segment very long then occasionally an oesophagostomy is formed to allow drainage of saliva and sham feeding (this technique is rarely required) for closure of long gaps various procedures are used including gastric transposition or tubes fashioned either from stomach or bowel TOF - surgical closure required via thoracotomy approach - pre-operative NBM until fistula closed at surgery (to prevent aspiration). Postoperative care (Oesophageal atresia) Routine postoperative ventilation is not always required and should be judged by anaesthetist/ surgeon. If endotracheal re-intubation is required on the neonatal unit, extreme care should be exercised to avoid overextension of the neck and bag and mask ventilation should be avoided if possible. Trans-anastomotic feeding tubes placed during surgical repair permit early enteral feeding Some surgeons prefer oral feeds to be delayed until a contrast swallow has been performed to exclude a large anastomotic leak (around 5-7 days postop). Retropleural drains are rarely used but are removed when satisfied no anastomotic leak is present. Antibiotic cover is usually used intraoperatively but should not usually be continued postoperatively for longer than 48 hours. Antireflux treatment should be considered in all patients following oesophageal repair because of the high incidence of reflux and potential for exacerbating anastomotic stricture. Long term problems Gastro-oesophageal reflux is very common Oesophageal dysmotility may lead to swallowing and feeding problems Feeding problems due to oral aversion secondary to long term Replogle tube use - refer to Speech Therapist early in these cases Strictures of anastomosis site may occur and later oesophageal dilatation may be necessary Tracheomalacia causing the characteristic chronic "TOF cough" Page 11 of 23

12 4.5 EXOMPHALOS (OMPHALOCOELE) Anterior abdominal wall defect involving the umbilicus with abdominal contents outside the abdominal wall but covered by a membrane Diagnosis is usually made on antenatal ultrasound scan. Associations approximately 50% have another major anomaly and of these 37% have GI problems (malrotation, Meckel s diverticulum, and atresias). ~20% have cardiac anomalies and 30% have karyotype abnormalities. Also associated with Beckwith Weideman Syndrome. Initial management Birth SHO/ANNP & Registrar/Consultant to attend. There is no contraindication to vaginal birth. Avoid giving bag & mask ventilation and have a low threshold for intubation during initial resuscitation. Insert a large bore NG tube as early as possible, aspirate and then leave on free drainage. Wrap exomphalos in sterile cling film for protection and in order to prevent fluid and heat loss if sac ruptured. The exomphalos should be handled minimally as the membrane can be very fragile and easily damaged. If prescribed (dependent on surgeon preference), apply thin layer of flamazine around base of exomphalos. Examine carefully for other congenital anomalies. Establish IV access and start IV fluids as early as possible. Replace NG losses 4 hourly with 0.9% saline + KCl (10mmol/500mL) Monitor urine output and assess fluid requirements carefully on a daily basis. Start IV antibiotics - benzylpenicillin, gentamicin and metronidazole. Ensure vitamin K is given Arrange echocardiogram, renal and cranial u/s scan and karyotype (if not done antenatally). Surgical management It is usual to aim for early initial surgery i.e. within 24 hours. Operation depends on size of lesion and its contents. It is usual to aim for primary closure but may need silo with closure in stages (see under gastroschisis). Post-operative establishment of enteral feeds - see under gastroschisis. Page 12 of 23

13 4.6 GASTROSCHISIS This is a defect of the anterior abdominal wall usually to the right of and separate from the umbilicus with abdominal contents outside the abdominal cavity with no covering membrane. Diagnosis is usually made on antenatal ultrasound scan. Associations - ~15% have associated anomalies of these ~20% are GI i.e. malrotation and atresias and ~2% are cardiac Aims 1. Initially cover bowel to prevent fluid loss and damage 2. Application of silo to contain bowel and allow staged reduction Delivery Baby to be born ideally by vaginal delivery Junior trainee/annp & senior trainee/consultant to attend Paediatric surgery registrar to be informed and to attend delivery where possible Resuscitaire to be prepared lined with cling film for immediate covering of bowel. Once initial assessment and resuscitation is completed, bowel to be covered and a large bore (size 8) nasogastric (NG) tube to be inserted to ensure adequate bowel decompression. Avoid giving bag & mask ventilation and have a low threshold for intubation during initial resuscitation The visible intestine should be minimally handled and avoid traction on the bowel & mesentery (reduced venous return and shock, or compression at edge of abdominal wall defect with bowel ischaemia). Bowel should be supported or baby nursed laterally to ensure minimal movement of bowel in relation to the mesentery If baby s perfusion is poor at delivery, consider obtaining venous access and giving a fluid bolus (20ml/kg 0.9% saline) on the resuscitaire Initial NICU management Nurse baby in giraffe incubator, with use of additional arch for silo support. Central and peripheral temperature to be recorded Intravenous access to be established for immediate IV maintenance fluids Consider early IV bolus(es) of 0.9% Saline for circulatory support due to fluid losses Nasogastric tube (size 8) to remain on free drainage and hourly aspiration. Start IV antibiotics - benzylpenicillin, gentamicin and metronidazole until silo is removed and defect is closed. Ensure Vitamin K is given Surgical registrar should ensure the attending surgical consultant is aware that the baby has been born and that a silo procedure is planned. Insertion of preformed silo by paediatric surgery registrar (if competent to do so) or consultant. This is most commonly performed on NICU. Planning for the procedure, with appropriate sedation and pain relief, should involve timely discussion between the NICU and paediatric surgical teams - If it is felt likely to be straightforward, it can be performed with 25-50mcg/kg morphine given as sedation/pain relief - With larger lesions, discussion is recommended with senior neonatologist and/or surgeon, regarding likelihood of difficulty in procedure and need for intubation and ventilation - In some cases the procedure may need to occur in ECH theatres Pain assessment to be ongoing and recorded hourly. Additional pain relief to be prescribed as required and prior to any tucks to silo. Silo to be suspended from top of incubator under minimal tension Arrange an echocardiogram and renal and cranial u/s scans. Management with Silo in place Well-placed percutaneous central venous catheter (PICC) line to be secured to enable parenteral nutrition. Page 13 of 23

14 Patient to remain NBM. Replace NG aspirates intravenously 4 hourly with 0.9% saline + KCl (10mmol/500mL) Silo base to be covered in gauze to allow for estimation of intra-abdominal fluid loss. Silo losses to be replaced ml for ml with 4.5% Human Albumin Solution Ensure maintenance of umbilical cord: cover with gauze and cling film and ensure gauze is kept moist at all times. Cord is needed for abdominal repair. Monitor urine output and carefully evaluate fluid requirements at least daily Close clinical monitoring and regular monitoring of biochemical and blood gas parameters. Observe for signs of hypovolaemia. Monitor the colour and state of the bowel in the Silo. Inform the surgical registrar if bowel changes colour (becomes dusky, grey). Also inform surgical team if Silo becomes dislodged. Daily reduction of silo by paediatric surgery team (ensure adequate pain relief) Defect closure Will be done in theatre usually after 5 to 7 days. Aim for sutureless closure, but may need general anaesthesia and formal suture closure if not possible. Ventilation may initially be more difficult post-operatively as the abdominal cavity is now tense and can impede chest movement. High frequency oscillation may be considered in this situation. Paediatric surgeon will advise about postoperative antibiotic usually hours. Dressing will remain in place for at least ten days after sutureless closure. Commence enteral feed when NG aspirates reduces and bowels opens. The median time to full feeds is days post repair. Continue TPN until full enteral feed is established Page 14 of 23

15 4.7 ANO-RECTAL MALFORMATIONS Background Wide spectrum, distal end of the hindgut fails to develop a normally patent opening in the anatomically correct position i.e at the centre of the anal sphincter muscle complex. In most cases, the anus is imperforate and the intestine terminates in an abnormal ectopic fistulous opening in the perineum, urethra or bladder in males or in the perineum or vestibule in females. Incidence: 1 in 5000 live births; 2% positive family history; slightly more in males than females. Associated with other congenital anomalies such as renal, cardiac, vertebral, oesophageal and limb in 50-60% of cases (eg VACTERL, Trisomy 22 (cat-eye syndrome), Short-rib Polydactyly Syndrome, Caudal Regression. Types: ARM can either be low or high. - In low anomalies, the anal passage may be misplaced in front of where it should be located (ectopic) or it can be narrow (stenosis). Constipation is a common problem with this anomaly. - In high anomaly, the rectum may be connected to the urinary passage e.g. rectovesical and rectourethral fistula i.e. the anal opening is in an abnormal position at the site of fistula. A membrane may be present at the site of normal anal opening (imperforate anus). In a small proportion of patients there may not be a fistula connection between the rectum and urinary passage. - In high ARM, faecal incontinence is a common problem because the anal sphincters are poorly developed and neuropathy associated with sacral abnormalities may be present. - Persistent cloaca: complex anomaly in which the urethra, vagina, and rectum, all terminate in a single common channel with a single perineal opening. Antenatal detection unusual as only rarely associated with polyhydramnios or dilated bowel on ultrasound scan Presentation (usually from 24hrs) Usually noted at routine 1 st examination Vomiting +/- dehydration Abdominal distension, visible bowel loops Failure to pass meconium Clinical Examination A detailed physical examination is necessary to determine the patency and position of the anus or fistula. Abdominal distension with visible loops, Imperforate anus, signs of rectourinary or perineal fistulae Abnormal genitalia and confluence of urethra, vagina, and rectum in a single channel (cloaca) Any other associated anomalies including spine Investigation An abdominal X-ray (cross table lateral view) after 16 to 24 hours may be necessary to determine the distance of terminal rectum from the skin, however this is done less frequently. Patient should have an x-ray sacrum and ultrasound scan of renal tracts and spinal cord prior to discharge to identify any associated anomalies. Echocardiogram should be done pre-operatively if antenatal or clinical evidence of cardiac anomaly. Magnetic Resonance Imaging (MRI) of spine may be required if a spinal anomaly is present. Page 15 of 23

16 Management Admit to NNU Refer to Paediatric Surgeons NBM and place wide bore NGT (size 8) to decompress abdomen (aspirate then put on free drainage) IV access Ensure vitamin K is given Bloods (FBC, group & save, renal profile, blood culture, blood glucose, blood gas, karyotype) IV fluids Replacement of NG losses 4 hourly (0.9% saline with 10mmol KCl/ 500mL) Give prophylactic antibiotic (trimethoprim) until underlying urological anomalies are excluded. Surgical treatment Treatment depends upon the nature of malformation, associated abnormalities & condition of the child. Children with low ARM e.g. anal stenosis or anovestibular fistula may be treated initially by anal dilatation to decompress the bowel followed by definitive procedure e.g. anoplasty or anal transposition at a later stage. All newborn boys and girls, diagnosed with ARM without a perineal fistula (high malformation) will require formation of an emergency colostomy to treat the intestinal obstruction. A definitive reconstructive procedure to create new anal opening will be done within 3 months of birth e.g. posterior sagittal anorectal plasty (PSARP). In persistent cloaca, complex reconstructive procedures may be necessary. Refer to Paediatric Urologist Urologist will advise about specialized investigations including vaginogram, micturiting cystourethrogram (MCUG), vaginoscopy and cystoscopy. Post-operative care After colostomy, baby can start oral feeding as soon as nasogastric aspirate has reduced in volume and become clear, and following discussion with surgeon. Parents should be taught by nurses in collaboration with stoma nurse specialist how to manage stoma bag, and how to perform anal dilatation by surgeon. Anal dilatation usually commences days post-operatively. Antibiotics should be given for at least 5 days post operatively. Remove urinary catheter 4-6 hours after epidural or nurse controlled analgesia (NCA) is discontinued. Catheter stays 5-7 days after posterior sagittal ano-recto plasty PSARP reconstruction (Surgeon will advise). Page 16 of 23

17 4.8 DELAYED PASSAGE OF MECONIUM Most healthy babies pass meconium within 24 hours of birth. Delay after 24 hours is unusual and underlying pathology should be considered. Review full history with mother & midwives. Look in maternal notes for any evidence of polyhydramnios or other abnormalities on antenatal scans e.g. dilated loops of bowel. Fully examine baby and check anus is patent. If < 24 hrs old, baby is well with no vomiting and normal examination then observe closely If > 24 hrs old, or < 24 hrs but with concerning features in the history or on examination, consider bowel obstruction, Hirschprung's Disease, enterocolitis and sepsis: - admit to the neonatal unit - inform SpR / Consultant - request AXR and discuss with consultant +/- Paediatric Surgeon In cases of early discharge, it must be stressed to the mother and midwives that if there is delay in passage of meconium greater than 24 hrs then the baby should be reviewed as soon as possible. If a baby has been given a suppository to aid passage of meconium then this baby should still be discussed with a Paediatric Surgeon in view of the possibility of Hirschprung's Disease. If a meconium plug is passed, IRT (spot of blood on Guthrie card) and CF genetic studies should be checked. Hirschsprung s disease should also be considered. Page 17 of 23

18 4.9 HIRSCHSPRUNG S DISEASE Anatomy and Physiology Hirschsprung s Disease is also known as congenital aganglionic megacolon. It is a congenital disorder of the rectum and colon in which ganglion cells are absent in the wall of bowel causing a functional obstruction. Incidence of 1 in Male:Female ratio 4:1. Length of affected gut varies: - Short segment (Rectosigmoid) 75% - Long Segment (Ascending or transverse colon) 17% - Total Colonic 8% - Small bowel 1-2% Downs syndrome associated with 5-15% Familial incidence for short segment about % Clinical Features Failure to pass meconium in the first 24 hrs after birth in an otherwise well infant. Abdominal distension. Bile stained vomiting. Rectal examination reveals a rush of air and explosive stool. A plain film of abdomen shows multiple distended loops of bowel with paucity of gas in the rectum. Differential diagnoses include malrotation with volvulus, intestinal atresia, meconium ileus, meconium plug, anorectal malformation. Chronic constipation and failure to thrive in an older child. NICU management Inform Paediatric Surgery team. Keep Nil by mouth. Secure an intravenous access and maintenance of intravenous fluids. Pass a nasogastric (NG) tube and place on free drainage. 1-4 hourly aspiration of nasogastric tube. Replace NG losses intravenously ml for ml with 0.9% saline and add 10 mmol of potassium chloride in 500 ml of solution. Digital rectal examination followed by regular rectal washouts to decompress bowel (see separate rectal washout guideline) Consider blood tests including blood gases, FBC, U&E, group and cross match if surgery is indicated. A plain film of abdomen. Feeding can be commenced after bowel decompression. Consider contrast enema after discussion with surgical team. Rectal suction biopsy (gold standard) to confirm diagnosis (see guideline below). Teach parents how to do rectal washout if appropriate before discharging the patient home for elective pull-through operation at a later date. Surgery A pull-through procedure is carried out as a one stage or multi stage procedures. Post-operatively, feeding is gradually commenced when there is evidence of bowel activity (see post-op feeding guideline) Page 18 of 23

19 Outcome Enterocolitis occurs in up to 27% of patients post operatively though incidence decreases with age. Constipation and faecal incontinence may be a problem. Mortality is rare, although significant with enterocolitis. Most children will lead a normal life. RECTAL SUCTION BIOPSY Introduction Rectal Suction Biopsy has been used for over 30 years to obtain tissue for the diagnosis of Hirschsprung s disease 1 and is now the gold standard 2. Indications Neonates presenting with failure to pass meconium in the first 24hrs of life. Neonates with recurrent Necrotizing enterocolitis. Neonates with colonic atresia. Older children with chronic constipation, emesis and abdominal distension. Contra-indications Children with serious intercurrent illness or clotting abnormalities. Neonates under 2kg in weight. (Not definitive, individual case needs to be discussed with surgeons and neonatologists.) Rectal suction biopsy has been shown to be less accurate in children of 3yrs and over 3. Preparation Obtain consent from parents for biopsy. - Complications include: Infection, Perforation, Bleeding or Inadequate biopsy. Inform histopathology of imminent fresh sample by contacting the Pathology Office on extension Provide patient s name, date of birth and expected time of arrival of sample. Consider omitting feed if feed due within 1 hour of procedure. Baby can be fed immediately following procedure. Use rbi2 suction biopsy hand piece and single use capsule pack from theatres. Administer a single dose of intravenous Co-amoxiclav (30mg/kg). Perform a digital rectal examination and rectal washout as per guidelines. Procedure Assemble hand piece, single use capsule with blade, tubing and a 5ml syringe. Insert device into rectum with biopsy window facing posteriorly (towards sacrum) up to a level of 3cm from the anal verge (using the 10mm insertion depth indicators on the capsule). Failure to pass the device as far as 3cm may result in a misleading sample from physiological hypoganglionic zone. With the device correctly positioned, firmly withdraw the syringe plunger to 5ml (applying approximately 10mmHg of suction) and press the thumb trigger to collect a biopsy. Release the suction and withdraw the device. Remove the sample from the single use capsule. - Assess the sample for adequacy: An adequate sample is at least 2mm in diameter and composed of at least one-third submucosa and appears globular in shape. - Place the sample in a dry specimen pot (i.e. not in formalin or saline) and clearly label it with patient details and the level at which it was taken. Take another biopsy using the procedure outlined above at 4cm from the anal verge and rotate the barrel of the device from the original biopsy attempt to prevent traumatising the same area of mucosa and place in a second, labelled pot. Page 19 of 23

20 A third biopsy capsule is available. Should a second biopsy attempt at the 3 or 4cm level be required. Post-Procedure Dispose of sharps (single use capsules contain scalpel blades) safely. Document the entire procedure in the notes. Instruct the nurse caring for the patient to conduct hourly cardiovascular observations and nappy inspection for the next 6hrs and report any signs of excess blood loss immediately. Ensure that the fresh samples are immediately transported to the histopathology lab with a completed form. Return the hand piece to theatres with its packaging for autoclaving. No rectal washout for 48hrs following rectal suction biopsy, however a digital Per Rectal examination can be done to relieve abdominal distension. 1) Noblett HR. A rectal suction biopsy tube for use in the diagnosis of Hirschsprung's disease. J Ped Surg 1969;4(4): ) Martucciello G, Pini Prato A, Puri P, et al. Controversies concerning diagnostic guidelines for anomalies of the enteric nervous system: A report from the fourth international symposium on Hirschsprung s disease and related neurocristopathies.j Ped Surg 2005; 40: ) Croffie JM, Davis MM, Faught PR, et al. At What Age Is a Suction Rectal Biopsy Less Likely to Provide Adequate Tissue for Identification of Ganglion Cells? J Ped Gastro and Nut 2007; 44(2): Page 20 of 23

21 4.10 RECTAL WASHOUT Principles The aim is to instil saline into rectum and then drain out saline plus stool and gas. This process is repeated until rectum is clear (more than just doing an enema). Indication and frequency to be decided by the surgical team (consultant/spr) Babies with Hirschsprung s may be discharged prior to surgery with regular rectal washouts being performed by the parents. Equipment 1. Appropriate catheter: use size 10 to 14 nelaton catheter for infants 2kg in weight; size 8 to 10 for <2kg. Smaller tubes will block very easily. Do not use stiff tubes such as suction catheters or chest drain tubing. 2. Warm 0.9% saline at body temperature (does not need to be intravenous quality). Warm by standing container in hot water. Test temperature with back of hand ml Bladder syringe with plunger removed. 4. Lubricant (supplied with nelaton catheter.) 5. Disposable gloves. 6. Inco-pads. 7. Jug and 2 silver bowls to collect drained saline/stool. Technique Explain procedure to parents. Wash hands, put on apron and gloves. Expose baby and assess the abdomen for colour, distension, rigidity and abdominal vein distension. Position baby on his/her back with legs elevated, or on his/her left side, cot in flat position. First perform gentle rectal examination with tip of little finger (no deeper than first knuckle). Baby may respond by passing stool. Insert lubricated catheter at least 3-5 cm, and advance tube as far as possible. Should slide easily do not force. If there is difficulty inserting the catheter 5cm, there may be stool very low in rectum. Repeat gentle rectal, and insert catheter again. If you still have resistance, instil 20mls of saline in an attempt to soften the stool (as described below). If this does not clear the rectum and allow you to insert the catheter further, stop and inform surgical team. Attach barrel of syringe (plunger removed) to catheter. Pour warm saline (10-20ml in baby) into syringe and run under gravity. If the saline fails to go in, gently push the saline with the syringe plunger into the bowel over 1-2 minutes. Once the saline has gone in, with the bed at 45 degrees (head up), disconnect the syringe, lower the syringe below the level of the body and drain out the mixture of saline, stool and gas (drainage may occur around the catheter as well as through it). Gentle abdominal massage may assist drainage. Repeat until effluent clear. Finish with repeat rectal and abdominal examination. If the catheter does not drain - Remove and check for blockage by stool, then try again - Perform rectal this may encourage the baby to pass stool. - If no stool drains, the abdomen is flat (+/- the baby has recently passed stool) it is likely that there is no further stool to come. Wait until the next washout is due. Page 21 of 23

22 - However, if the abdomen is distended inform the surgical team. Once procedure completed, wash and dress baby, and check temperature. Measure and empty the fluid in the bowl. The amount, taking into account any spillages, should be approximately the same as you started with. Document fully the procedure in the baby s notes, including: volume of saline used, colour, consistency and amount of stool, degree of abdominal distention pre- and post- washout, and whether flatus passed. Page 22 of 23

23 4.11 NEONATAL PRESENTATION WITH BILIOUS VOMITING Bile stained vomiting is a green colour vomit (or nasogastric drainage) and an underlying surgical cause eg. mechanical or functional intestinal obstruction should be excluded. Causes of Bilious vomiting in infancy Malrotation and midgut volvulus: this diagnosis can be difficult, with insidious onset and can lead to gut ischaemia/infarction Duodenal atresia. Jejuno-ileal atresia. Colonic atresia. Hirschsprung disease. Meconium ileus. Meconium plug Small left colon syndrome Milk inspissations Imperforate anus Non-surgical: sepsis; idiopathic bilious vomiting Clinical Features Abdominal distension Failure to pass meconium in the first 24 hrs after birth in an otherwise well infant AXR: Paucity of gas in the abdomen (proximal bowel obstruction) or multiple distended loops of bowel with paucity of gas in the rectum (distal bowel obstruction). NICU management Assess vital signs: airway, breathing, circulation Keep nil by mouth Secure intravenous access and intravenous fluid maintenance Consider intravenous bolus of 0.9% saline 20ml/kg over 30 to 60 minutes if patient is dehydrated and monitor the response. Pass a size 8F nasogastric tube (NG) and place on free drainage. Aspirate NG tube 1-4 hourly (depending on clinical condition of patient) and replace NG losses ml for ml with 0.9% saline and 10 mmol of potassium chloride added to 500 ml of solution Consider the following investigations: o Blood gases including lactate o FBC, U&E, group and cross match o Blood cultures & antibiotics o A plain film of abdomen o Ultrasound scan of abdomen. Inform Paediatric Surgery team Discuss with surgical team regarding specialized investigations of upper gastrointestinal contrast study or lower gastrointestinal contrast study Surgery This will be guided by the radiological findings Outcome Majority have a good outcome following surgery/treatment and live a normal life. Page 23 of 23