110 SECTION II Pediatric Critical Care Tools and Procedures chapter and includes those discussed previously in the Thoracen tesis section 152 Malposition is the most common complication of chest tube[.]
110 S E C T I O N I I Pediatric Critical Care: Tools and Procedures chapter and includes those discussed previously in the Thoracentesis section.152 Malposition is the most common complication of chest tube placement Any structure within the thorax may be inadvertently penetrated with the use of excessive force Placement in the lung parenchyma is relatively common, potentially leading to bronchopleural fistulas.153 Vascular injury may occur with high placement, intraabdominal organ injury with low placement, and left-sided placement can lead to thoracic duct injury and development of chylothorax Deep placement may lead to mediastinal perforation.154 Computed tomography is required to evaluate the exact placement of chest tubes in cases in which inadvertent misplacement or complications are suspected Contraindications Summary Procedure Tube thoracostomy is a common procedure in pediatric critical care medicine With attention to detail in the hands of a skilled provider, this procedure may be accomplished safely and with minimal risk Small-caliber tubes should be used when possible; chemical debridement with fibrinolytic agents may be used to restore the patency of clogged tubes and are of therapeutic benefit in cases of empyema Drainage of a pericardial effusion can be performed either by simple needle aspiration or by insertion of a drainage catheter If the procedure is for diagnosis only and the effusion is small, then needle drainage is adequate However, if tamponade is present, the effusion is sizable, or the effusion likely will continue to accumulate, insertion of a catheter for continuous drainage is indicated Supplies and equipment required for pericardiocentesis are summarized at ExpertConsult.com Pericardiocentesis Pericardiocentesis is the aspiration of fluid or air from the pericardial space Pericardiocentesis can be performed emergently without any imaging guidance techniques However, it should be undertaken only in dire circumstances because of the risk of the procedure and the higher failure rate when no guidance is used Interventional cardiologists, when available, may be invaluable resources in performing these high-risk procedures Indications Drainage of a pericardial effusion due to any cause is absolutely indicated when cardiac tamponade is present Drainage is often recommended if the effusion is large, even in the absence of tamponade, for diagnosis and fluid removal.155 For small effusions, pericardiocentesis may be indicated for diagnosis alone In pediatric patients, pericardial effusions most commonly occur with postviral or idiopathic pericarditis, but they are also seen with postpericardiotomy syndrome, collagen vascular disease, oncologic disease, and, rarely, uremia.155 Purulent pericarditis resulting from Staphylococcus aureus or Streptococcus pneumoniae infection can be seen in cases of concomitant pneumonia with empyema Although rare in developed countries, tuberculous pericarditis should be considered as a cause in high-burden tuberculosis areas or among immigrants from those areas Drainage of purulent pericarditis is indicated for relief of tamponade, prevention of constrictive pericarditis, and diagnosis and drainage of infection With purulent pericarditis, open surgical drainage may be more effective because of the difficulty in draining purulent exudate.156 If using a tube for pericardiocentesis and drainage, instillation of a fibrinolytic agent such as alteplase (recombinant tissue plasminogen factor) may be considered with purulent effusions.157 Traumatic pericardial effusions secondary to penetrating trauma often require surgical drainage of the blood because tamponade is common Pneumopericardium secondary to pulmonary air leaks in mechanically ventilated patients is usually well tolerated hemodynamically but may require drainage, especially in small infants, because of the development of tamponade There is no absolute contraindication to pericardiocentesis in an emergency situation The presence of aortic dissection or myocardial rupture is considered a major contraindication The presence of a bleeding diathesis or coagulopathy is another contraindication Open drainage is preferred over closed drainage when the patient has traumatic tamponade and is in cardiac arrest When the effusion is loculated in a location not easily reached via the subxiphoid approach, needle pericardiocentesis is contraindicated because the risk of complications increases while the possibility of successful drainage is low Monitoring for Pericardiocentesis Critically ill patients require continuous pulse oximetry and ECG monitoring Blood pressure must be measured very frequently Before pericardiocentesis, airway patency and respiratory support should be ensured In patients with tamponade physiology, procedures such as rapid sequence intubation or positive pressure ventilation can precipitate a sudden decrease in preload as an antecedent for impaired cardiac output and cardiac arrest Volume resuscitation, conversely, can augment preload and temporarily improve hemodynamics Monitoring the ECG tracing while advancing the pericardiocentesis needle enables the clinician to detect needle contact with the epicardium, which helps prevent cardiac puncture Echocardiographic guidance is recommended for most pericardiocentesis because it can be done at the bedside and is logistically less complex.158 Echocardiographic scanning is indicated prior to needle drainage or catheter insertion for any reason except tamponade with cardiac arrest The echocardiogram can visualize the size of the effusion; its distribution around the heart, including any loculations; the presence of fibrin or clots; and evidence of tamponade Tamponade can be diagnosed using twodimensional imaging when the right atrium collapses during late diastole Technique Needle aspiration can be performed blindly in the event of a true emergency, such as traumatic tamponade; however, the technique has higher complication and failure rates Among the potential chest sites for pericardiocentesis in infants and children, the subxiphoid approach is the safest and most common, although other approaches have been described The approach is extra-pleural and, in patients with normal anatomy, avoids major vessels such as the internal mammary, coronary, and pericardial arteries.155 The subxiphoid and lower costal margin are prepared with 2% chlorhexidine The area is draped in a sterile fashion Lidocaine local anesthesia is infiltrated at the junction of the xiphoid and left 110.e1 Supplies and equipment required for pericardiocentesis include the following: Needles for drainage range in size from 14- to 20-gauge depending on the type of fluid and size of the patient For thicker consistency fluids, such as pus or blood, a larger-bore needle is used A steel needle, such as a vascular introducer needle or spinal needle, can be used However, an IV catheter is often more effective because once the fluid is reached, the steel inner needle can be removed from the IV catheter, leaving the softer, needleless catheter in place while the fluid is aspirated This process decreases the risk of cardiac puncture Syringes, three-way stopcock, and short extension tubing are assembled for aspiration A 5- or 10-mL slip-tip syringe is used when accessing the pericardium for easier manipulation A larger 20- to 30-mL syringe may be needed for fluid drainage, depending on the predicted volume The stopcock and short tubing are useful when draining large amounts of fluid Equipment for insertion includes 2% chlorhexidine solution, sterile gloves and drapes, and 1% lidocaine for local anesthesia 4 Appropriate sterile sample tubes should be available for collection of fluid for chemical, cellular, and microbiological analysis A cardiac monitor is essential for determining arrhythmias during the procedure Catheter, dilator, and flexible J-wire are necessary when the catheter will be left in place Placement in the pericardial sac of a 5- to 8-Fr pigtail catheter with multiple side holes is recommended The size of the patient and viscosity of the fluid determine the size of the catheter If the fluid is fibrinous in appearance by echocardiography, then a larger-bore catheter should be placed Several pigtail catheters are manufactured specifically for fluid drainage, often available as kits that also contain an appropriately sized dilator and J-wire guide If a kit is not available, then a venous dilator of appropriate size with a separate J-wire can be used A J-wire is used to prevent another puncture of the pericardium or heart using a straight wire Before the needle is inserted, the wire, dilator, and catheter must be checked to ensure that their sizes are compatible CHAPTER 14 Pediatric Vascular Access and Centeses Cardiac tamponade Pericardium Lower border of lung 111 the pericardial sac, then the needle is appropriately placed in the pericardium Once the needle is determined to be well positioned in the pericardial sac, if a catheter is to be inserted, then the J-wire can be passed through the needle as with standard Seldinger technique The needle is removed, and the dilator is passed over the wire to open the tissues outside the pericardium and enlarge the puncture in the pericardium The dilator is removed, taking care to leave the J-wire in good position The catheter is passed over the wire into the pericardial sac Its position can be confirmed echocardiographically The wire is then removed The connecting tubing and three-way stopcock are connected and the fluid is aspirated The tubing can be connected to a drainage bag for removal of fluid that continues to accumulate A sample of the aspirated fluid should be sent to the laboratory for appropriate analysis and culture The catheter is secured with suture and covered with an occlusive dressing A chest radiograph should be taken at the end of the procedure and daily to confirm the catheter position Maintenance • Fig 14.8 Insertion of needle for pericardiocentesis at the junction of the xiphoid and the left costal margin, aiming toward the left shoulder (From Brundage SI, Scott BG, Karmy-Jones R et al Pericardiocentesis and pericardial window In: Shoemaker WC, Velmahos GC, Demetriades D, eds Procedures and Monitoring for the Critically Ill Philadelphia: Elsevier; 2002.) costal margin The needle is inserted at a 30- to 45-degree angle and directed toward the left clavicle (Fig 14.8) The slip-tip syringe is attached and is aspirated continually while the needle is inserted Needle advancement is halted when air or fluid is aspirated During insertion, the needle is guided using two-dimensional echocardiography The echocardiographic probe is placed on the chest, where the fluid is best seen The needle tip is identified by ultrasound and followed as the needle is advanced.159 Another technique involves mounting the needle on the echocardiographic probe, which has been placed in a sterile sleeve The needle is advanced while the operator also handles the probe This technique allows the use of locations other than the subxiphoid approach for insertion of the introducer needle, with the potential for better fluid visualization.160 After the fluid has been echocardiographically evaluated, the patient is placed supine with the head elevated approximately 30 degrees If blood is obtained, analysis is necessary to determine whether the blood is of pericardial or intracardiac origin Several techniques are helpful for this determination The hematocrit of pericardial fluid will be lower than that of intracardiac blood, which will be equal to the patient’s hematocrit Dropping a few milliliters of the fluid on gauze sponges determines whether the fluid will clot Fluid that does not clot is pericardial; fluid that does clot is most likely intracardiac blood Another technique involves injection of small amounts of saline microbubble contrast (saline in a syringe that has been agitated) through the introducer needle while imaging with echocardiography If contrast bubbles are seen in the heart, then the tip of the needle is intracardiac or intravascular If bubbles appear in The catheter is simple to maintain The dressing should be changed according to the ICU protocol for CVCs The fluid in the drainage bag should be measured and the amount recorded on a regular schedule If fluid is no longer draining, then a small amount (1–2 mL) of heparinized saline can be infused into the pericardium through the stopcock after preparation with antiseptic solution This process can release any fibrinous material occluding the catheter If no fluid is forthcoming, then echocardiography can be performed to determine whether residual pericardial fluid remains If residual fluid is present, the catheter is again flushed in an attempt to open it up If the fluid had originally been purulent, then instillation of a fibrinolytic agent may allow better drainage If no fluid remains, the catheter can be removed, depending on the patient’s condition and underlying cause of fluid development Complications The most serious and immediate mechanical complications of pericardiocentesis are myocardial puncture or laceration, vascular injury (coronary, intercostal, internal mammary, or intraabdominal), pneumothorax, air embolism, and arrhythmia (ventricular and supraventricular) Coronary laceration occurs rarely, resulting in acute myocardial ischemia Transperitoneal needle passage can traverse intraabdominal organs The liver is most commonly involved but is associated with low risk of significant hemorrhage Perforation of a hollow viscus is theoretically possible but rarely reported Infection of the indwelling catheter can occur but is rare because the catheter is not in place for more than to days Summary Pericardiocentesis, with or without catheter placement, is indicated for relief of cardiac tamponade and for a diagnosis of certain pericardial effusions It is a lifesaving technique for patients with tamponade Patients needing emergency pericardiocentesis are monitored with pulse oximetry and ECG monitors Used in conjunction with guidance techniques such as echocardiography or electrocardiography, pericardiocentesis can be performed safely in patients of all ages 112 S E C T I O N I I Pediatric Critical Care: Tools and Procedures Abdominal Paracentesis Abdominal paracentesis is the percutaneous sampling and drainage of peritoneal fluid by needle aspiration through the abdominal wall Analysis of ascitic fluid, combined with a detailed history and physical examination, frequently confirms the etiology of ascites Indications Paracentesis may be used diagnostically for new fluid accumulations or therapeutically to relieve cardiopulmonary or end-organ (e.g., renal) compromise resulting from large accumulations of fluid Diagnostic paracentesis is indicated in any patient with new-onset ascites, with existing ascites and clinical deterioration, and in cases of suspected bacterial peritonitis.161,162 Therapeutic paracentesis should be used for the relief of abdominal compartment syndrome secondary to massive ascites.163–165 Contraindications Paracentesis has few to no absolute contraindications Relative indications include small amounts of ascitic fluid and severe bleeding diatheses such as seen in disseminated intravascular coagulation.166,167 Uncorrected coagulopathy and thrombocytopenia may rarely predispose to bleeding complications However, prophylactic platelet or plasma transfusion is not recommended.161,162 Severe renal dysfunction has the highest association of bleeding complications after paracentesis.168 Skin infections or wounds at the insertion site can lead to introduction of new infection into the peritoneum and thus should be avoided Massively distended bowel as can be seen in severe ileus or prior surgical scars with bowel adhesions present a risk of bowel perforation with paracentesis An uncooperative patient can lead to damage of the underlying vascular structures or bowel This risk may be mitigated by the appropriate use of sedation and analgesia Procedure When present, physical examination findings of flank dullness, shifting dullness, and fluid waves support the presence of ascites and guide selection of the needle insertion site, while ultrasound guidance improves the success rate of paracentesis Additionally, when physical examination findings are insufficient or difficult due to body habitus, ultrasonography can detect smaller amounts of fluid, differentiate free from loculated fluid, and is more sensitive than physical examination in diagnosing ascites.161,162,166,169,170 Technique After the patient’s bladder is emptied fully by voiding or catheterization, the patient is positioned in a semi-recumbent position The site of needle insertion is selected by physical examination or ultrasound Bowel floats in ascites and tends to stay in a nondependent, midline position Therefore, the preferred site for paracentesis is in the dependent, lateral area of the left lower quadrant: two fingerbreadths (2–3 cm) in both the medial and cephalad directions from the anterior superior iliac spine Additionally, studies have shown that the abdominal wall is thinner and the pool of ascites deeper in the left lower quadrant.171 The right lower quadrant should be avoided owing to the cecum’s proximity to the abdominal wall Potential insertion sites with surgical scars should also be avoided owing to the risk of underlying bowel adhesions.161,162,166 The inferior epigastric arteries running cephalad midway between the pubic symphysis and anterior iliac spine in the rectus sheath should be avoided In patients with portal hypertension, the midline may become vascularized and should be avoided, as well as any visible collateral vessels, to reduce the chance of hemorrhagic complications.161,162,166,172 While continually observing aseptic technique, the entry site is disinfected with chlorhexidine or povidone-iodine and draped in sterile fashion Always aspirating while advancing, the skin and subcutaneous tissue down to the peritoneum are infiltrated with local anesthetic using a small-gauge needle If no commercially assembled paracentesis kit is available, spinal needles are ideal for paracentesis fluid sampling (20- to 22-gauge for small children, 16- to 20-gauge for larger children) Prior to needle insertion, the skin at the insertion site should be pulled downward approximately cm to create a nonlinear Z-track While aspirating with an attached syringe, the clinician advances the needle slowly until free flow of fluid into the syringe is noted, but it is removed immediately if frank blood is aspirated Approximately 20 to 40 mL of ascitic fluid is sufficient for diagnostic evaluation, but much larger volumes may be removed for therapeutic paracentesis in tense ascites If fluid return stops or is sluggish, changing the patient’s position may be helpful Once fluid collection is complete and the needle is removed, direct pressure with gauze is applied and a sterile pressure dressing is placed When ongoing drainage is needed, a small-caliber pigtail catheter can be placed using the modified Seldinger technique (as described in the Tube Thoracostomy section) Complications Serious complications of abdominal paracentesis are very rare (1%–3%), but several have been described.162,166 The most commonly described complication is persistent leakage of ascitic fluid, which can be avoided if proper Z-track technique and smallcaliber needles are used.173 Ongoing fluid leaks can be managed by closing the defect with suture or cyanoacrylate skin adhesive.174 While even more rare, abdominal wall hematoma or bleeding, bladder perforation, and intestinal perforation can occur In patients with severe bleeding complications, 70% had renal dysfunction, 59% had coagulopathy, and 8% had thrombocytopenia.168 The risk of intestinal perforation is increased with previous history of abdominal surgery owing to adhesions and can be minimized by avoiding surgical scars for the needle insertion site Additionally, intestinal perforation from paracentesis has been reported with marked bowel distension; though rare, decompression should be considered prior to paracentesis.175 Bladder emptying decreases the risk of bladder perforation Ultrasound guidance can further decrease the risk of organ perforations Strict adherence to sterile technique and avoidance of areas of skin or soft-tissue infection for needle insertion decrease the risk of infection Hypotension may result if a large volume of ascites is removed at once (.15–20 mL/kg); in that circumstance, postprocedural albumin administration is sometimes required Interpretation Analysis of ascitic fluid in combination with clinical assessment generally will yield a definitive diagnosis The characteristics of ascitic fluid in various conditions are summarized in eTable 14.2 Fluid studies obtained should include total protein, albumin, Gram stain and culture, and cell count with differential Optional 112.e1 eTABLE Characteristics of Ascitic Fluid in Various Conditions 14.2 Condition Clinical Characteristics Laboratory Findings Portal hypertension Straw colored, sterile SAAG 1.1 g/dL Total protein ,2.5–3.0 g/dL WBCs ,250–500/uL, ,1/3 neutrophils Spontaneous bacterial peritonitis Cloudy or turbid Gram positive ,10%, cultures may be negative, single organisma PMNs 250/uL Total protein ,1 g/dL LDH and glucose similar to serum SAAG usually 1.1 g/dL Secondary bacterial peritonitis Gram positive, multiple organisms PMNs 250/uL Total protein g/dL LDH serum Glucose ,50 mg/dL SAAG ,1.1 g/dL Chylous ascites Milky or yellow, with recent fat ingestion WBCs 1000–5000/uL, predominately lymphocytes Triglycerides 200 mg/dL, usually 1000 mg/dL Cholesterol 48 mg/dLb Pancreatic ascites Turbid, tea colored, or bloody WBCs and total protein increased Amylase and lipase serum Amylase levels may be falsely low in young infants, but lipase always highc Urinary ascites Protein ,1 g/dL Urea and creatinine serumd Malignant ascites Bloody Protein and LDH elevated SAAG ,1.1 g/dL Nephrotic syndrome Straw colored SAAG ,1.1 g/dL Total protein ,2.5 g/dLc Tuberculous ascites Yellow or rarely bloody, may have fibrin clots Total protein 2.5 g/dL WBCs 1000/uL, primarily lymphocytes PCR usefule PMNs: Absolute, corrected number of polymorphonuclear leukocytes for red blood cells, where one PMN is subtracted from the absolute PMN number for every 250 red cells/mm3 a Data from Kandel G, Diamant NE A clinical view of recent advances in ascites J Clin Gastroenterol 1986;8(1):85–99 b Data from McGibbon A, Chen GI, Peltekian KM, et al An evidence-based manual for abdominal paracentesis Dig Dis Sci 2007;52(12):3307–3315 c Data from Glauser JM Paracentesis In: Roberts JR, Hedges JR, eds Clinical Procedures in Emergency Medicine Philadelphia: WB Saunders; 1991 d Data from Runyon BA Care of patients with ascites N Engl J Med 1994;330(5):337–342 e Data from Uzunkoy A, Harma M, Harma M Diagnosis of abdominal tuberculosis: experience from 11 cases and review of the literature World J Gastroenterol 2004;10(24):3647–3649 LDH, Lactate dehydrogenase; PCR, polymerase chain reaction; SAAG, serum-to-ascites albumin gradient; WBCs, white blood cells ... drainage range in size from 14- to 20-gauge depending on the type of fluid and size of the patient For thicker consistency fluids, such as pus or blood, a larger-bore needle is used A steel needle, such... the IV catheter, leaving the softer, needleless catheter in place while the fluid is aspirated This process decreases the risk of cardiac puncture Syringes, three-way stopcock, and short extension... been placed in a sterile sleeve The needle is advanced while the operator also handles the probe This technique allows the use of locations other than the subxiphoid approach for insertion of the