 \200 \200 \200 \200 \200 07_McClure_07.indd 208 11/14/2012 2:31:44 PM CENTRAL VENOUS CATHETERIZATION VIA A PERIPHERAL VEIN 209 Central venous catheterization via a peripheral vein For administration of prolonged or con centrated IV \202 uids or drugs. Sites Suitable sites include the veins of the antecubital fossa, or long saphenous vein ant erior to the medial malleolus or inferior \200\223medial to the knee. Less preferred sites include the axillary or scalp veins. Equipment \200 \200 \200 \200 Sterile surgical instruments including \201 ne forceps and scissors. Sterile gloves, gauz e swabs, gown, and drapes. Antiseptic solution, e.g. 0.5% chlorhexidine. 23 or 27G silastic long line catheter. 27G should only be used when a 23G line cannot be inserted. 2 \200\223 5mL syringe and heparinized (1U/mL) saline solution. Introducer, e.g. 19G butter \202 y ne edle, 20G IV cannula. Sterile adhesive tape and transparent occlusive dressing. \200 \200 Procedure \200 Measure distance from insertion site to just above the right atrium. Placing the catheter t ip in the right atrium risks pericardial tamponade. Catheter insertion should be performed using strict aseptic technique. Wash hands and put on sterile gloves, gown, +/ \200\223 sur gical mask. Set out equipment and prime catheter with sterile heparinized saline. Apply tou rniquet proximal to selected insertion point. Immobilize relevant limb, then clean insertio n site with antiseptic. Place sterile drapes around insertion point to create sterile \201 eld. Insert introducer needle into the vein until blood \202 ashes back. If using a cannula, remove stylet. With \201 ne forceps advance catheter through introducer needle/c annula. Continue to advance catheter into vein until the desired distance is reached. Tip: often the catheter will meet resistance as it becomes wedged against a kinked vein or valve . Milking in a proximal direction with a \201 nger over the catheter tip may facilitate f urther advancement. Remove tourniquet and then \202 ush catheter with heparinized saline. Once fully inserted, withdraw introducer needle/cannula. Remove from line after unscrewing catheter hub. Reconnect hub to catheter. Ensure haemostasis at puncture site by applying g entle pressure with sterile gauze swab. This may take some considerable time! Secure line i n place by using thin strips of sterile adhesive tape and sterile transparent occlusive dre ssing. Start infusion of heparinized saline (1U/mL) to keep line patent. Con \201 rm cathe ter tip placement with CXR. This may be aided by the injection into the line of 0.5mL of co ntrast solution immediately before X-ray. Ideally, the catheter tip should lie just proxima l to the right atrium. Withdraw the catheter before use if it is in the right atrium. \200 \200 \200 \200 \200 \200 \200 \200 \200 07_McClure_07.indd 209 11/14/2012 2:31:44 PM CHAPTER 7 Practical procedures 210 Airway management Before effective ventilation can take place, the airway must be patent. T his can be ensured in various ways, alone or in combination. \200 Head tilt: slightly extended in older children. Chin lift: chin to pull the tongue forward. Jaw thrust: jaw to pull the tongue forward. Guedel oro-pharyngeal airway: \202 ange reac hes the lips. Be careful not to push the tongue back. To determine the correct size, hold t he airway along the line of the jaw with the \202 ange in the middle of the lips. The end of the correctly sized airway should be level with the angle of the jaw. Endotracheal intu bation: Suction: However, if the methods described above are not successful in obtaining an adequate airway, check that the airway is not obstructed by secretions, vomitus, blood, me conium, etc. If there is obstruction on inspection, or it is obvious from the start, suctio n should be performed using an appropriate suction catheter connected to a suction source. Tracheotomy: nasal endotracheal intubation fails or is contraindicated. Perform only if alr eady trained by a senior doctor. The description of this technique is beyond the scope of t his book. tilt the head back gently to a neutral position in newborns, using 1 or 2 \201 ngers apply forward pressure to just under the apply forward pressure behind one or both angles of the slip the airway over the tongue until the \200 see b p.212. not routinely required, especially in newborn resuscitation. bypasses upper airway obstruction and when oral oro- 07_McClure_07.indd 210 11/14/2012 2:31:44 PM MASK VENTILATION 211 Mask ventilation This procedure is useful during resuscitation or for short periods of as- sisted ventilation. It can be performed using a self-in \202 ating bag and face mask with an appropriately-sized reservoir bag; alternatively, use a mask connected to a \200\230T \200\231 piece and a continuous supply of gas, as well as a pressure-limiting device. In th e latter, a breath is given by occluding the open aperture of the \200\230T \200\231 piece . Procedure \200 \200 b p.210). Ensure patent airway (see Select appropriate size mask. It should be big enough to be able to cover the face from the bridge of the nose to below the mouth, but not extend over the e dge of the chin or over the orbits. In infants a round mask, e.g. Laerdal or Bennett \200 \231s mask, is most appropriate. In older children the Laerdal molded mask is more suitab le. Connect face mask to an appropriate self-in \202 ating bag or tubing with a \200\230T \200\231 piece and then to an oxygen or air supply at an adequate \202 ow rate, e.g. 5 \200\2238L/min in the newborn. In newborns, a pressure-limiting valve should used and initi ally be set at 725 \200\22330cmH2O. Apply mask to face over mouth and nose, and apply enoug h downward pressure to make an effective seal. Give in \202 ation breaths by either compre ssing self-in \202 ating bag or occluding open aperture of \200\230T \200\231 piece. Obse rve and ausculate chest wall for adequate in \202 ation. Note whether condition of child i s improving or deteriorating. If in \202 ation is poor or child deteriorating, check airwa y is not obstructed and use one or more techniques described on b p.210 to ensure patent ai rway. Prolonged mask ventilation is likely to lead to a distended stomach. Insert an oro-gastric tube on free drainage to decompress the stomach and pre- vent diaphragmatic splinting. 07_McClure_07.indd 211 11/14/2012 2:31:44 PM CHAPTER 7 Practical procedures 212 Endotracheal intubation Indications This procedure is used as part of advanced resuscitatio n and care. Equipment \200 Appropriately-sized laryngoscope: blade size starts at 0 (7.5cm long) for use in preterm in fants. Use size 1 (10cm) in term infants. In older children use curved blade laryngoscopes (Macintosh). ETT 1000 \200\2233000g; 3.5mm when >3000g. The appropriate size then increases as child size increases up to male adult size of 8 \200\2239mm. Cole (shouldered) ETTs are suitable for oral intubation in newborns. Straight (non-shouldered) tubes can be used for oral or nasal intubation. Appropriately-sized introducer if required. Lubricating jelly if attempting nasal intubation. Magill forceps if attempting nasal intubation. Suction cathete r and tubing connected to suction source. Appropriate ETT connection adaptors, tubing, and O Fixation device and tape. neonatal laryngoscopes are straight; size: 2 \200\2232.5mm (internal diameter) in infant <1000g; 3mm when \200 \200 \200 \200 \200 2 source. Procedure \200 Oral intubation is preferred during short-term intubation or during resuscitation. Nasal in tubation has advantages if ventilation is prolonged. Check laryngoscope light, O Connect ch ild to pulse oximeter and cardiac monitor. Sedation or anesthesia should be given prior to elective intubation. Pre-oxygenate the child by hyperventilation with 85% O 2 for 15 \200 \22330s prior to elective intubation. Place the child in the supine position with the head in the neutral position and the neck slightly extended. Stand immediately behind the child \200\231s head. If nasal intubation is being performed, a prelubricated ETT should be passe d into one nostril as far as the nasopharynx prior to insertion of laryngoscope. If the ETT will not pass easily, do not try force, as this may lead to penetration of the cribriform plate. Open the mouth and use suction to clear airway secretions. Holding the laryngoscope in the left hand, initially insert the blade to the right side of the mouth and advance to the base of the tongue. Once inserted move the laryngoscope blade into the center of the mo uth, thereby pushing the tongue to the left. Advance the blade further until epiglottis is seen and then insert blade tip into the valleculla (space between base of tongue and epiglo ttis). Vertically lift up the whole blade, thereby exposing the vocal cords (see Fig. 7.3). Apply cricoid pressure with the little \201 nger of the left hand to see the vocal cords . Perform suction if needed. \200 \200 \200 2 supply, and suction. \200 \200 07_McClure_07.indd 212 11/14/2012 2:31:45 PM ENDOTRACHEAL INTUBATION 213 If the vocal cords cannot be seen after 30s do not try to attempt blind intubation. Abandon the attempt, maintain patent airway (b p.210), and perform mask ventilation (b p.211), bef ore trying again. Once the vocal cords are seen, insert the ETT between the vocal cords. If dif \201 cult, or performing nasal intubation, use the Magill forceps with the right hand to advance the ETT tip. If using a straight tube, the ETT should be advanced until the thi ck black line at the tip is level with the vocal cords. If using a Cole ETT, advance it unt il the shoulder just reaches the vocal cords. If using a cuffed tube advance until the cuff is just below the vocal cords and no further. Then in \202 ate the cuff with air using a syringe. Once intubation is successful, connect tubing and ventilate. Visually check chest movement and auscultate over each lung to ensure appropriate and equal bilateral air entry. If this procedure is successful, SpO 2 and heart rate should improve. Fix ETT in place app ropriately following local institutional guidelines. Perform a CXR to con \201 rm position of ETT, which should ideally be 1 \200\2232cm above the carina, depending on the childs \200\231 size. Causes of failure to intubate include: poor visualization of vocal cords due to over extension of neck or advancement of laryngoscope too far into the esophagus; spasm of vocal cords (wait, as almost certainly vocal cords will open eventually \200\224do not attempt to force ETT through as this may cause damage); anatomical abnormalities, e.g. lary ngeal atresia; vocal cord oedema. Conditions that may give an impression of failed intubati on (little or no chest movement on ventilation after intubation) include: thoracic patholog y (e.g. tension pneumothorax, diaphragmatic hernia); intubation of the right main bronchus (detected by unequal air entry); and particulate obstruction of airway or ETT. \200 \200 \200 Laryngoscope Vocal cords Trachea Esophagus Fig. 7.3 Anatomy of laryngeal intubation. 07_McClure_07.indd 213 11/14/2012 2:31:45 PM CHAPTER 7 Practical procedures 214 Insertion of a chest drain Indications This procedure is used to drain a pneumothorax, pleu ral effusion or chy- lothorax. In an emergency (most commonly due to a tension pneumotho- r ax), drainage should \201 rst be performed by inserting 21 \200\22323G butter \202 y int o the affected side at the second intercostal space in the mid-clavicular line. The butter \202 y tubing can be placed under water following insertion; alter- natively, a 3-way tap can be attached allowing aspiration with a syringe. Once the child is stable, a formal ches t drain should be inserted. Equipment \200 \200 \200 Antiseptic solution: Local anesthetic: Intercostal drain: young adults. Straight surgical s calpel blade, artery forceps, and suture. Sterile dressing pack (including gauze, gloves, d rapes). Underwater drainage system and suction pump. Steri-Strips e.g. 0.5% chlorhexidine. e.g. 1% lidocaine, needle, and 10mL syringe. size ranges from 8 \200\22312Fr for newborns up to 18Fr for \200 \200 \200 and plastic transparent dressing, e.g. Tegaderm . Procedure \200 Lie the child supine with the affected side raised by 30 \200\22345 using a towel. Raise the arm towards the head. Suitable sites are the fourth intercostal space in the mid-axilla ry line (be careful to avoid the nipple), and second intercostal space in mid- clavicle lin e. Chest drain insertion should be performed using strict aseptic technique. Wash hands and put on sterile gloves, gown, +/ \200\223 surgical mask. Clean skin over the insertion site with antiseptic solution. Prepare sterile \201 eld, then in \201 ltrate small amount of local anesthetic into the tissues down to the pleura. Wait 1 \200\2232min, then make a sma ll skin incision with the scalpel just above and parallel to rib. Note: Blood vessels lie j ust below each rib. Using artery forceps make a blunt dissection down to and through the pa rietal pleura. Using forceps clamp chest drain and then insert into pleural space. Most cli nicians remove the trocar before insertion. Aim to push the chest drain tip towards the lun g apex. In the event of a small pneumothorax aim the tip in the direction of the pneumothor ax remembering to aim anteriorly (air rises in the ill child lying supine). Connect the dra in tightly to the underwater drainage system, unclamp drain, and apply negative pressure of 5 \200\22310cmH2O. Bubbling should start to occur. \200 \200 \200 07_McClure_07.indd 214 11/14/2012 2:31:45 PM INSERTION OF A CHEST DRAIN 215 Using single sutures close skin wound closely around chest drain. Do not use a purse string suture as this will increase scarring. Apply zinc oxide tape to chest drain and \201 x t o skin using sutures. Perform a CXR to check drain position and pneumothorax or effusion dr ainage. Remove drain when con \201 dent it is no longer required, e.g. pneumothorax has re solved and there has been no bubbling for >24hr. This is done by releasing holding sutures, then rapidly removing drain followed by immediate pressure and gentle rubbing with a gauze swab to close the underlying tissues. Apply Steri-Strip across skin incision to provide air-tight seal. Perform a CXR to con \201 rm that a signi \201 cant pneumothorax has not re-accumulated. Note: If pleural \202 uid is required for diagnostic purposes only, then simple needle aspiration at the above sites is the technique of choice. \200 07_McClure_07.indd 215 11/14/2012 2:31:45 PM CHAPTER 7 Practical procedures 216 Intraosseous infusion Indication This procedure is used for emergency vascular access to gi ve resuscitation drugs or \202 uids, or for blood sampling when vein cannulation dif \201 cult. Equipment \200 \200 \200 \200 22G IO needle or 1.5G spinal needle in neonates. Alcohol impregnated swab. 5mL syringe. Loc al anesthetic, e.g. 1% lidocaine, 2mL syringe and a small gauge needle if patient conscious and local anesthetic appropriate. Sites \200 (cid:1)3 years old: tuberosity, or anterolateral surface of femur, 2 \200\2233cm above late ral condyle. Any age: anteromedial proximal aspect of tibia, 1 \200\2232cm below tibial medial malleolus of the tibia above the ankle. Procedure \200 \200 \200 \200 \200 Identify site and inject local anesthetic if the patient is conscious. Clean skin with an a lcohol impregnated swab. Insert at 90 to the skin. Advance into bone using a rotary actio n. Advance trocar until bone cortex is reached, when a give will be felt. Remove stylet, at tach syringe, and aspirate to con \201 rm position. Obtain any required blood samples. Flu sh needle with 0.9% saline to again con \201 rm position. Swelling outside the bone indica tes needle displacement. Infuse any required \202 uids (any \202 uid that can be given IV can be used). Obtain conventional vascular access as soon as possible and then remove IO needle. \200 Intracardiac injection Indicated only during resuscitation when all other attempts at secur ing vascular access have failed. Equipment \200 \200 Alcohol impregnated swab. 21G needle and syringe containing resuscitation drug. Procedure \200 \200 Attach needle and syringe. Flush needle with drug to expel air. Locate site: edge (immediat ely below the line joining the nipples). Clean site with an alcohol impregnated swab. Inser t needle and aspirate syringe as needle is inserted. Once blood \202 ashes back, stop adv ancing. Inject resuscitation drug(s). 4th intercostal space immediately lateral to the left sternal \200 \200 \200 07_McClure_07.indd 216 11/14/2012 2:31:45 PM PERICARDIOCENTESIS 217 Pericardiocentesis Indications Therapeutic drainage of a pericardial effusion or for diagno stic purposes. Equipment \200 \200 \200 \200 Alcohol impregnated swab/antiseptic solution, e.g. 0.5% chlorhexidine. 21G needle or IV can nula and 10 \200\22320mL syringe. Sterile gloves, drapes, gown, and adhesive plaster. Steri le sample containers if pericardial \202 uid analysis intended. Procedure \200 \200 Lay child on a 30 slope to cause effusion to pool inferiorly. Locate insertion site; this lies just below the angle between the sternum and the left costal margin. Use sterile glov es and gown. Clean the site with antiseptic and place sterile drapes around insertion site. Local anesthetic in \201 ltration may be appropriate. Insert needle connected to syringe at an angle of 30 to the skin and advance slowly, aiming towards the left shoulder. Gentl y aspirate the syringe as needle is inserted. Stop when pericardial \202 uid (usually str aw-colored) is aspirated and remove desired amount as indicated. Once drainage is complete, remove needle and apply adhesive plaster. \200 Abdominal paracentesis This is indicated for drainage of ascites when it compromises breath ing, e.g. hydrops fetalis, or for diagnostic purposes, e.g. following trauma. Equipment As for b p.217, Pericardiocentesis. Procedure \200 In infants, the left iliac fossa is the preferred site (which avoids liver and spleen). In older children, a midline site between the symphysis pubis and the umbilicus is preferred b ecause of less vascularity. Lay the child supine. If ascites is minimal also tilt towards t he left side. b Except in emergencies, clean and prepare the site as described in p.217, Pe ricardiocentesis. Attach needle to the syringe and carefully insert it at 90 to the skin. Aspirate \202 uid and place it in sample containers. If large amounts of \202 uid are to be drained use an IV cannula. Once inserted, remove the stylet, and leave the cannula in place to reduce the risk of bowel perforation. If prolonged drainage is needed, attach the cannula to the skin using adhesive tape or stitches. Once complete, remove needle and appl y sterile plaster to site. If a large amount of \202 uid is withdrawn, drainage should be followed by IV infusion of albumin. \200 \200 \200 07_McClure_07.indd 217 11/14/2012 2:31:45 PM CHAPTER 7 Practical procedures 218 Urethral bladder catheterization Indications This procedure is used for bladder decompressi on, e.g. potential obstruc- tion, accurate measurement of urine output, and collection of u rine for bacteriological investigation in suspected urinary tract infection. Equipment \200 \200 \200 \200 \200 3 \200\2238Fr urinary catheter (depending on child \200\231s size). Anesthetic lubricating gel, e.g. 0.1% lidocaine gel. Water-based antiseptic solution, e.g. 0.5% chlorhexidine. Ste rile urine sample container. Sterile gloves and adhesive tape. Procedure \200 Lay child in supine position with hips abducted, with an assistant holding the child. Clean penile tip or vulval area with antiseptic solution. Apply anesthetic lubricating gel to ca theter tip and urethral opening. Partially withdraw foreskin in males. Part the labia in fe males. Insert and advance catheter into urethra in a posterior manner until urine is obtain ed, indicating that the bladder has been entered. Once in the bladder, in \202 ate the cat heter balloon with saline if the catheter is intended to be indwelling. Use adhesive tape t o secure the catheter to the thigh. Connect catheter to the urine collection bag or aspirat e urine for analysis. \200 \200 \200 \200 07_McClure_07.indd 218 11/14/2012 2:31:45 PM SUPRAPUBIC ASPIRATION OF URINE 219 Suprapubic aspiration of urine Optimal method for obtaining urine for bacteriology in a chi ld <2yr old. Equipment \200 \200 \200 \200 \200 21 \200\22323G needle. 2 \200\2235mL syringe. An alcohol impregnated swab. Sterile urine sa mple container. Cotton wool or gauze swab and adhesive plaster. Procedure \200 \200 Wait at least 30min from last urination. If in doubt as to whether the bladder contains ade quate urine, perform bladder US to con \201 rm. Place child supine (with an assistant hold ing hips abducted) and then identify site \200\224midline anterior lower abdominal wall 1cm above the pubic bone. Clean site with an alcohol impregnated swab. Insert needle connected to the syringe at 90 to the skin, aspirating continuously until urine is obtained. Inser t to almost the depth of the needle. If no urine is obtained, partially withdraw it before inserting again at different angle. Once required urine is aspirated, remove the needle, pr ess on puncture site with cotton wool or gauze swab, and then apply an adhesive plaster. Pl ace urine in sterile container. If unsuccessful, repeat the procedure 30 \200\22360min late r. \200 \200 07_McClure_07.indd 219 11/14/2012 2:31:45 PM CHAPTER 7 Practical procedures 220 Lumbar puncture Indications To obtain sample of CSF for microbiological, biochemi- cal, or metabolic analysis; therapeutically drain CSF in communicating hydrocephalus. Contraindicat ions Include thrombocytopenia or coagulation defect, raised intracranial pressure, and sign i \201 cant cardiorespiratory compromise, as positioning may risk cardiorespiratory arrest (see also b p.109). Site L3 \200\223L4 intervertebral space (spinal cord may be as low as L2 in neonates). Equipment \200 \200 \200 \200 24 \200\22322G 1.5 inch spinal needle. Antiseptic solution, e.g. 0.5% chlorhexidine. Steril e dressing pack (including gauze, gloves, drapes). Sterile sample containers; usually 3 are needed for M,C&S, protein, and glucose, but sometimes also for virology, cytology, or immu nology. Adhesive plaster or aerosol plastic dressing spray. Pressure manometer and 3-way ta p if measuring CSF opening pressure. \200 Procedure \200 Apply topical local anesthetic cream to site under an occlusive dressing for 45min before t he procedure. Place child on their side with back along an edge of a \201 rm surface. Ask an experienced assistant to \201 rmly, but gently, hold child with the spine maximally \202 exed. Beware compromising respiration! Locate site. L4 spinous process lies on a line joining the iliac crests. Using strict aseptic technique, clean the site with antiseptic s olution and then create a sterile \201 eld by surrounding it with sterile drapes. Inject local anesthetic into site if child is Insert spinal needle into intervertebral space slowl y at 90 to the skin and aim in the direction of the umbilicus, i.e. slightly cephalad. Ad vance needle slowly until there is a sudden give, which occurs as the dura is penetrated. R emove stylet; wait for CSF to drain. If no CSF drains, advance needle very slowly and withd raw stylet every 1 \200\2232mm to check for drainage. If bone is struck or needle is fully inserted and no CSF obtained, remove the stylet and then withdraw cannula very slowly in ca se CSF appears. Allow 10 drops of CSF to drain into each sample bottle. If measuring CSF pr essure, connect 3-way tap before collecting samples and direct \202 uid up attached manom eter. Once opening pressure is measured, turn 3-way tap to allow CSF to drain. If therapeut ic CSF drainage is required, drain required amount. Once drainage is complete, remove the n eedle and rub the puncture site with a sterile gauze swab while applying pressure. Cover si te with an adhesive plaster or aerosol plastic dressing. The child should lie \202 at for the next 6hr and have hourly neurological observations and BP measurement. \200 \200 \200 (cid:2)6mths old. \200 \200 \200 07_McClure_07.indd 220 11/14/2012 2:31:45 PM CEREBRAL VENTRICULAR TAP 221 Cerebral ventricular tap Indications This procedure is done for drainage of CSF in non-comm unicating hy- drocephalus, to obtain CSF for microbiological testing, e.g. to diagnose vent riculitis, and to administer intraventricular antibiotics. Equipment As for lumbar puncture (b p.220). Procedure \200 Before the procedure is undertaken, cerebral lateral ventriculomegaly must be con \201 rme d by cranial US. Place the baby supine, with an assistant \201 rmly holding the baby \200 \231s head. Measure the necessary depth required for needle insertion. Palpate and locate t he lateral corner of the anterior fontanelle on the intended side to drain. Shave a small a rea of the scalp at the needle insertion point if required. Set out sample containers +/ \200\223 CSF pressure manometer if needed. Full aseptic technique should be used. Wash hand s and put on sterile gloves, gown, +/ \200\223 surgical mask. Clean area with antiseptic so lution and create a sterile \201 eld with sterile drapes. Insert needle into the lateral corner of the fontanelle in a direction slightly forward and inward, aiming toward the inne r canthus of the ipsilateral eye. After the needle is inserted to the predetermined distanc e, remove stylet and CSF should drip out. If CSF pressure measurement is required, attach m anometer and allow it to \201 ll until measurement is complete. If CSF drainage or sample is required, then allow \202 uid to drip out spontaneously into containers until require d amount is drained. Once required CSF has been drained, remove the needle and then cover w ith adhesive plaster or spray with plastic dressing to seal. The child should lie \202 at for the next 6hr and have hourly neurological observations and BP measurement. \200 \200 \200 \200 \200 \200 07_McClure_07.indd 221 11/14/2012 2:31:45 PM CHAPTER 7 Practical procedures 222 Exchange transfusion Indications \200 Severe or rapidly rising hyperbilirubinaemia, e.g. due to severe rhesus or other haemolytic disease (see b p.194). Cardiac failure secondary to severe anemia (with normal or increase d plasma volume), e.g. hydrops fetalis due to rhesus haemolytic disease. Disseminated intra vascular coagulation. Polycythaemia with a venous haematocrit >70% and/or symptomatic. Acut e poisoning, including that due to metabolic disease. \200 \200 Exchange is achieved by sequentially removing 10 \200\22315mL of blood from the child and t hen infusing warmed (37 ), cross-matched, fresh (<72hr old), rhesus \200\223ve, cytomegal ovirus (CMV) \200\223ve, irradiated or leucocyte \201 l- tered (to prevent graft vs. hos t disease), partially packed or whole blood. Exchange transfusion can be performed by eithe r both withdrawing and then infusing blood via a single central venous catheter (e.g. umbil icus venous catheter), or withdrawing blood via a central catheter (arterial or venous) or peripheral arterial catheter and replacing it via a second central or peripheral venous cat heter. Blood volume (mL) to remove and then replace (i.e. exchange) is: \200 Severe anemia with hydrops requires a single volume exchange, i.e. 80mL/kg body weight. Sho uld be performed over a minimum of 1hr. Removal of toxins, e.g. bilirubin or ammonia, requi res a double volume exchange, i.e. 160mL/kg in newborns. This replaces 790% of total blood volume and should be performed over a minimum of 2hr. To treat polycythaemia, a dilutional exchange transfusion is performed. The required exchange volume depends on the haematocrit (Hct) and can be calculated using the formula: Volume = [measured Hct \200\223 desired Hct] x blood volume measured Hct In a dilutional exchange replace blood with 0.9% saline 0.45% albumin. Equipment \200 \200 \200 \200 \200 \200 \200 \200 Venous and arterial catheters, either central or peripheral. Two 20mL syringes and 3-way ta ps. Blood administration set and warming coils. Calibrated waste blood container. +/ \200 \223 High \202 ow rate infusion pump. Appropriately cross-matched blood (see Indications) . ECG and BP monitor. Sterile dressing pack (including gown, gauze swabs, drapes, and glove s). 07_McClure_07.indd 222 11/14/2012 2:31:46 PM EXCHANGE TRANSFUSION 223 Procedure \200 If not already present, insert central or peripheral venous/arterial catheters. Start conti nuous ECG and frequent BP monitoring. As a baseline, measure serum FBC, U&E, Ca gasses. Pri me blood administration set and warm blood to 37 C. Arrange for an assistant to keep a con stant accurate log of volumes removed and replaced throughout the procedure. Use a full ase ptic technique throughout the procedure. Wash hands and put on sterile gloves, gown, +/ \200\223 surgical mask. Connect 3-way taps into the system (exact arrangement depends on ch oice of method; see the following bullet points). If using a single central venous catheter , e.g. UVC, use two sequential 3-way taps to perform the following in order: \200 \200 2+, glucose, and blood \200 \200 \200 Withdraw 5 \200\22320mL blood from the baby using a syringe minutes. Turn \201 rst 3-way tap to allow blood to be syringed into a waste bag. Turn second 3-way tap to allow 5 \200 \22320mL, fresh, warmed blood to be drawn from pack. Turn tap and syringe fresh blood over a few \200 If using two catheters together, remove 5 \200\22320mL aliquots of blood from the central o r arterial catheter over 5 \200\22310min and then turn a single 3-way tap to allow blood to be pushed into the waste bag. Simultaneously, the same volume of fresh warmed blood is inf used into the patient via the other venous catheter using a high rate \202 ow infusion pu mp. A safe volume to remove each turn varies depending on size of infant. Remove 5mL aliquo ts for ELBW infants, increasing up to 20mL for full term infants. Apart from continuously m onitoring pulse, ECG, BP, and temperature, every 30 \200\22360min during the procedure meas ure blood gasses, FBC, U&E, serum Ca2+, and glucose. Measure again at the end of the proced ure, as well as a coagulation pro \201 le. Correct any abnormality found. Once procedure i s completed, leave catheters in place in case repeat exchange transfusion is required. slowly into baby (2 \200\2233min). Complications of exchange transfusion \200 Catheter-induced thrombotic or embolic phenomenon, e.g. portal vein thrombosis or NEC. Haem odynamic compromise, e.g. cardiac arrhythmia or hypotension. Metabolic, e.g. hypoglycaemia (transfused plasma often has a low blood glucose concentration due to red cell consumption) , hypokalaemia, hypocalcaemia, hypomagnesaemia, acidaemia. Coagulopathy or thrombocytopenia . Hypothermia. Infection: screened prior to transfusion. Graft vs. host disease: \200 \200 \200 bacteraemia, HIV, CMV, hepatitis B or C. Blood must be risk reduced by irradiation or leucocyte \201 ltration. 07_McClure_07.indd 223 11/14/2012 2:31:46 PM This page intentionally left blank 225 Chapter 8 Cardiovascular Common presentations 226 Cyanosis 226 Heart failure 226 Heart murmurs 228 Murmurs: clinical features 230 Acyanotic: congenital heart disease 232 Left to right shunt: atrial septal de fect 233 Ventricular septal defect 234 Persistent ductus arteriosus 234 Right to left shunt : tetralogy of Fallot 235 Transposition of the great arteries 236 Common mixing: complete a trioventricular septal defect 236 Tricuspid atresia 237 Aortic stenosis 237 Pulmonary steno sis 238 Coarctation of the aorta 238 Hypoplastic left heart syndrome 239 Total anomalous pu lmonary venous connection 239 Hypertrophic obstructive cardiomyopathy 240 Dextrocardia 240 Infection: infective bacterial endocarditis 242 Rheumatic fever 244 Pericarditis 246 Myocar ditis 248 Cardiomyopathy 249 Cardiac arrhythmias 250 08_McClure_08.indd 225 11/14/2012 2:33:24 PM CHAPTER 8 Cardiovascular 226 Common presentations The cardiovascular examination in children is described on b p.32. The majority of children with cardiovascular disease will present with one or more of the foll owing three clinical problems: \200 \200 \200 cyanosis; heart failure ( heart murmur ( b p.226); b p.228). Cyanosis Distinguishing between respiratory and cardiac causes of cyanosis is important (se e b pp.55, 60 \200\22362). Heart failure Heart failure may be manifested by symptoms of poor tissue perfusion alone (e .g. fatigue, poor exercise tolerance, confusion) and/or by symp- toms of congestion of circ ulation (e.g. dyspnoea, pleural effusion, pul- monary oedema, hepatomegaly, peripheral oede ma), without evoking compensatory mechanisms. The underlying pathophysiology mechanisms that lead to compromise of cardiac stroke volume, cardiac decompensation, and heart failure include: \200 \200 \200 \200 increased afterload (pressure work); increased preload (volume work); myocardial abnormalit ies; tachyarrhythmias. Causes of heart failure In children the most common cause of heart failure is congenital st ructural defects of the heart. \200 \200 Large left to right shunt: Left-sided obstructive lesions: of heart (within \201 rst few days of life). Cardiomyopathy: Myocarditis: Endocarditis. Myocardial ischaemia: disease. Ta chyarrhythmias: Acute hypertension. High-output: e.g. large VSD (not in \201 rst few days of life). coarctation of aorta; hypoplastic left side \200 \200 \200 hypertrophic; dilated; restrictive. viral; rheumatic fever. anomalous left coronary artery; Kawasaki \200 \200 supraventricular tachycardia. severe anemia; thyrotoxicosis; AV malformations. 08_McClure_08.indd 226 11/14/2012 2:33:24 PM HEART FAILURE 227 Clinical features The clinical features of heart failure depend on the degree of cardiac re serve. The most common symptoms and signs are those in keeping with increased compensatory sympathetic drive: \200 \200 \200 \200 \200 \200 sweating; breathlessness, tachypnoea, coughing, lung crepitations; poor feeding (infant), p oor weight gain, and failure to thrive; hepatomegaly; cardiomegaly; tachycardia/ \200\231ga llop \200\231 heart rhythm. There are usually few signs of systemic congestion as observed in adults. Only children wit h chronic heart failure, or adolescents, may have \200\230adult \200\231 signs such as oed ema, orthopnoea, paroxysmal nocturnal dyspnoea, ankle oedema and elevated JVP. Investigations These are directed at \201 nding a cause and quantifying function. \200 Chest radiograph: \200 \200 Echocardiography: Arterial blood gas: ECG: Serum electrolyt es: cardiac enlargement; lungs \200\224oligaemic/oedema. \200 \200 \200 congenital heart defects. reduced PO2/metabolic acidosis. not diagnostic, but may assist in establishing etiology. hyponatraemia due to water retention. Management The underlying cause of heart failure must be treated. General measures \200 \200 \200 \200 \200 Bed rest and nurse in semi-upright position: infants in chair/seat. Supplemental oxygen (no t in left to right shunt). Diet: Diuretics. Angiotensin converting enzyme inhibitors. suf \201 cient calorie intake. 08_McClure_08.indd 227 11/14/2012 2:33:24 PM CHAPTER 8 Cardiovascular 228 Heart murmurs Heart murmurs should be characterized in terms of type, location, radia- tion , and quality of sound. Murmurs are classi \201 ed as follows: Systolic: Diastolic: \200 pansystolic; ejection systolic. early diastolic; mid-diastolic. The location where a murmur is best heard may give a clue to the underly- ing etiology. \200 \200 \200 VSD \200\224often loud; innocent heart murmur \200\224soft. : aortic stenosis; pulmonary st enosis. Lower sternal edge: Upper sternal edge Base of neck: aortic valve lesion. Pathological heart murmur Characteristic features of pathological heart murmurs: \200 \200 \200 \200 \200 \200 \200 All diastolic murmurs. All pansystolic murmurs. Late systolic murmurs. Loud murmurs >3/6. C ontinuous murmurs. If there are associated cardiac abnormalities. Abnormal symptoms or sign s: \200 shortness of breath (SOB); \200 tiredness/easy fatigue; \200 failure to thriv e (FTT); \200 cyanosis; \200 \201 nger clubbing; \200 hepatomegaly. Innocent heart murmurs This is the commonest cause of a heart murmur in children. It arises due to the rapid \202 ow and turbulence of blood through the great vessels and across no rmal heart valves. It does not signify the presence of any under- lying cardiac abnormality or any other pathology. Characteristics of innocent heart murmur \200 \200 \200 \200 \200 \200 \200 Systolic in timing \200\224always. Short duration/low intensity sound. Intensi \201 es wit h increased cardiac output (e.g. exercise/fever). May change in intensity with change in po sture and head position. No associated cardiac thrill or heave. No radiation. Asymptomatic patient. Never diastolic. Types of innocent heart murmur Venous hum (uncommon) \200 \200 \200\230Machinery \200\231 quality sound. Upper left sternal edge. Due to blood \202 ow in great veins. Flow murmur \200 Short systolic murmur. Mid-left sternal edge. 08_McClure_08.indd 228 11/14/2012 2:33:24 PM HEART MURMURS 229 Often heard during acute illness with fever, disappears when fever resolves. Musical murmur Systolic murmur. Lower left sternal edge. 08_McClure_08.indd 229 11/14/2012 2:33:24 PM CHAPTER 8 Cardiovascular 230 Murmurs: clinical features A likely diagnosis can be assessed using the clinical examinatio n and fea- tures from CXR and ECG. Tables 8.1 and 8.2 summarize likely diagnoses given the characteristics of the murmur and the \201 ndings from your initial investigations. Table 8.1 Likely diagnoses based on clinical features of murmur Location of murmur Diagnoses Features Continuous murmur PDA (b p.234) Left clavicular (machinery) in child; LSE in preterm infant Acyanotic; bounding pulse; Long systolic murmur VSD (b p.234) Lower LSE (pansystolic) parasternal thrill Acyanotic Apex Mitral regurgitation Acyanotic Rheumatic fever Mid-LSE Tetralogy of Fallot (b p.235) Cyanotic; single S2 Ejection systolic murmur Upper LSE ASD secundum (b p.233) AVSD partial (b p.233) Acyanotic; \201 xed split S2; Acyanotic; \201 xed split S2; + Apical pan- systolic murmur PS (b p.238) CoA (b p.238) Upper LSE +/- thrill Acyanotic Upper LSE Acyanotic; weak or absent femoral pulses (if neonate); hypertensive in right arm (if older) AS (b p.237) Upper RSE Acyanotic; carotid thrill; delayed soft S2; small volume & slow rising pulse Key: AS, aortic stenosis; ASD, atrial septal defect; AVSD, atrioventricular septal defect; CoA, coarctation of the aorta;; LSE left sternal edge; RSE right sternal edge, LV, left ven tricle; PDA, persistent ductus arteriosus; PS, pulmonary stenosis; PV, pulmonary valve; S1, \201 rst heart sound; S2, second heart sound; VSD, ventricular septal defect. 08_McClure_08.indd 230 11/14/2012 2:33:24 PM INVESTIGATION OF SUSPECTED HEART PROBLEM 231