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Simulation Center Procedure Guide. Overview. Procedures Lumbar Puncture Central Venous Access Femoral Subclavian Internal Jugular Paracentesis Thoracentesis Indications / Contraindications Procedure Analysis of results Complications. Lumbar Puncture. Introduction
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Overview • Procedures • Lumbar Puncture • Central Venous Access • Femoral • Subclavian • Internal Jugular • Paracentesis • Thoracentesis • Indications / Contraindications • Procedure • Analysis of results • Complications
Lumbar Puncture Introduction • Least invasive and the most common method to obtain biological material from the central nervous system Indications for Procedure • Evaluation for meningitis • Evaluation for subarachnoid hemorrhage • Diagnosis and therapeutic removal of CSF in idiopathic intracranial hypertension • Diagnosis of other neurologic conditions
Indications for ProcedureLumbar Puncture Evaluation for meningitis • Based primarily on the overall clinical suspicion, because few signs (e.g., fever, stiff neck, change in mental status) or symptoms (headache, confusion) are individually reliable enough to be clear indications • Considered for adults with a change in mental status and development of fever not explained by something other than CNS pathology Evaluation for subarachnoid hemorrhage • The classic presentation sudden onset of severe headache, often accompanied by nausea, vomiting, syncope, and/or neck pain • Note that up to 50% of patients may have a “sentinel bleed” from a small leak in the days or weeks before a large and often neurologically devastating hemorrhage
Indications for ProcedureLumbar Puncture Diagnosis and therapeutic removal of CSF in idiopathic intracranial hypertension • Manifested by headache, nausea, and visual disturbances, intracranial pressure is elevated but findings from neuroimaging studies are normal • LP has been a standard adjunctive treatment for benign intracranial hypertension • Removal of 15-25 mL spinal fluid usually acutely lowers CSF pressure to less than 10 mm Hg Diagnosis of other neurologic conditions • In Guillain-Barré syndrome, cytologic-albumin dissociation (i.e., over-abundance of protein relative to cellular burden) may be observed. • In multiple sclerosis, an elevated level of myelin light chain may be observed.
Lumbar Puncture Contraindications • Suspected tumor, mass lesion, or increase in intracranial pressure • Skin infection at site of puncture • Bleeding disorders
ContraindicationsLumbar Puncture Increase in intracranial pressure • The following findings indicate the possibility of increased intracranial pressure and are contraindications to an LP before a CT • Patient older than age 60 years • Immunocompromised patient • Seizure within one week of presentation • Known CNS lesion • Altered level of consciousness • Inability to answer two consecutive questions correctly or follow two consecutive commands • Presence of gaze palsy • Abnormal visual fields • Facial palsy • Limb drift • Language abnormality • Papilledema
Lumbar Puncture Spinal needleselection • Traumatic spinal needles • The standard spinal needle • Beveled tip • Associated with greater CSF leakage than “atraumatic” needles • Atraumatic spinal needles • A blunt “pencil-tip,” and fluid is drained via a side port. • This design is theorized to reduce trauma to the dura, by separating it instead of cutting it, and thus reduce the incidence of dural puncture headache
Lumbar Puncture ANATOMY Interspace selection • In adults the spinal cord terminates at the L1 vertebra • Entry into the spinal canal must occur distal to this location • The fibers of the cauda equina extend distally from the L1 vertebra • The L3-L4 and the L4-L5 interspace are the preferred locations for puncture • L4 spinous process is at the level of the posterior-superior iliac crests, making these interspaces easily identifiable
Lumbar Puncture • Path of the spinal needle • Skin and subcutaneous tissues • Supraspinal ligament • Interspinous ligament • Ligamentum flavum • Dura • Arachnoid mater • Correctly positioned, the tip of the spinal needle will be in the subarachnoid space. (1) Intervertebral disc (2) Vertebral body (3) Intrathecal space (4) Epidural space which has the dura mater (5) spinal cord
Lumbar Puncture Anatomy of the lumbar vertebrae • The spinal needle accesses the spinal canal by traveling in between 2 adjacent spinous processes • The spinous processes are angled caudally (downwards), and thus the spinal needle must be directed cephalad (upwards) to gain access to the spinal canal and subarachnoid space • The space between adjacent spinous processes can be increased by flexing the lumbar region and the hips
Lumbar Puncture Procedure • Explain procedure to patient • Obtain written informed consent • Gather all equipment • Position the patient • Careful positioning is essential for successful performance of the LP • Lateral recumbent position • Place the patient on his or her side, with the lumbar region parallel and adjacent to the edge of the bed • Instruct the patient to flex the back and the hips as much as possible • Sitting position • Place the patient sitting on the edge of the stretcher • Instruct the patient to flex the lower back and the hips as much as possible • Avoid any lateral tilting of the torso, so that the plane of the spine is perpendicular to the plane of the bed
Lumbar Puncture Procedure (CONT) • Identify the landmarks • Palpate the superior portion of the posterior iliac crests, and then palpate the spinous processes in the midline at this level • The L4 spinous process is located at the level of the superior portion of the iliac crests • Puncture may occur immediately above the L4 process, in the L3-L4 interspace, or below it, in the L4-L5 interspace • Palpate the depression between the spinous processes in the selected interspace, and mark the entry site with a skin marking pen, or indent the skin with a needle-less syringe or ball-point pen • Put on a face mask and sterile gloves • Prepare and drape the region • Cleanse the skin with a sponge soaked with povidone-iodine or chlorhexidine, starting at the proposed puncture site and continuing in gradually larger concentric circles
Lumbar Puncture Procedure (CONT) • Apply a sterile, fenestrated drape over the needle entry site. • The drape should cover the posterior superior iliac spine, so that it may be palpated as a landmark during the procedure • Anesthetize the region • Direct the needle in the anticipated trajectory of the spinal needle, angled slightly cephalad and aimed at the umbilicus. • 3-5 mL anesthetic is ample • Assemble the remaining equipment • Make sure the stylet is fully inserted into the spinal needle. • Arrange the collection tubes in numerical order so that they are filled in the correct sequence
Lumbar Puncture Procedure (CONT) • Insert the spinal needle. • If using a traumatic needle, align the bevel so that it is facing the patient's side. • This needle orientation theoretically reduces the incidence of post-dural puncture headache, by allowing the cutting edges of the bevel to separate the longitudinal dural fibers instead of cutting them. • Make sure that the stylet is fully inserted. • Gently advance the needle into the skin. • The needle should be in the exact anatomic midline and aimed slightly cephalad, towards the umbilicus • Advance through the tissues, stop every 4 to 5 mm and withdraw the stylet to check for fluid return • Reinsert the stylet each time before the needle is advanced
Lumbar Puncture Procedure (CONT) • Insert the spinal needle (CONT) • When the subarachnoid space has been entered, spinal fluid will flow out of the needle • In most cases the needle will be inserted about 1/3 to 1/2 of its length • Measure the opening pressure • Attach the stopcock-manometer assembly to the hub of the spinal needle, and allow the CSF to rise in the column. • Normal CSF pressure is 7-18 cm H2O
Lumbar Puncture Procedure (CONT) • Collect the spinal fluid • Fill the tubes in the correct order: fill tube 1 first, tube 2 second, etc • Tubes 1 and 4 are generally sent for cell count and differential count, tube 2 is sent for chemistry studies, and tube 3 is used for microbiology • 1 mL fluid per tube is adequate for most indications • Remove the needle and clean the skin. • Replace the stylet before removing the needle. This theoretically reduces the incidence of post-dural puncture headache • Clean the skin to remove the antiseptic agent and apply a bandage over the needle entry site.
Lumbar Puncture Post-Procedure Care • Contrary to traditional teaching, instructing the patient to lie supine for a defined period after the procedure does not decrease the incidence of post-dural puncture headache • No other specific actions need to be taken after lumbar puncture • Treatment of specific conditions revealed by CSF analysis should be undertaken in a timely manner
Lumbar Puncture Complications • Post-dural puncture headache • Most frequently documented adverse outcome • Thought to be caused by persistent CSF leak through the penetrated dura • Cerebral herniation • Clinical signs and symptoms of herniation include acute onset of altered mental status, coma, respiratory depression, and focal neurological findings • Hemorrhagic complications • Traumatic taps (bleeding) are common during lumbar puncture and usually require no specific therapy • Local nerve root trauma and back pain • Rare, occurring in about 1 in 1000 procedures • Infection • Introduction of organisms into the CSF by passage of a needle through skin that is already infected is a theoretical risk for infection
Lumbar Puncture Analysis of results • Opening pressure • Normal opening pressure is 7-18 cm H2O • Cell counts • White blood cells (WBCs) • Normal CSF contains less than 5 WBCs/mm3 • RBCs • Normal CSF contains less than 10 RBCs/mm3 • The comparison of the red cell counts between tube 1 and tube 4 may be used to evaluate for traumatic tap. • Traumatic tap is suggested by a declining number of red cells in successive tubes. • Glucose • Normal CSF glucose level is 50 to 80 mg/dL (or two thirds of the serum glucose level) • Protein • Normal CSF protein levels are 14 to 45 mg/dL
CSF Cloudiness / Turbidity Lumbar Puncture A simple test of CSF turbidity is to see if normal print can be read easily through the sample – CSF should be crystal clear. Cloudiness usually appears at CSF WBC counts > 200x106 WBC/L
Lumbar Puncture Analysis of results • Special stains and cultures should be considered in immunocompromised patients • Hyphae are occasionally seen in Candida or other fungal meningitis. • Acid-fast staining should be done if tuberculosis is suspected. Sensitivity of the initial stain is only 37% but can increase with repeated stains. • Cryptococcus can be identified using India ink preparation 50% of the time. • Toxoplasmosis can be diagnosed with Wright or Giemsa stain.
Normal Bacterial Viral TB Cells 0-5 WBC/mm3 >1000/mm3 <1000/mm3 25-500/mm3 Polymorphs 0 predominate early +/- increased Lymphocytes 5 late predominate increased Glucose 40-80 mg/dl decreased normal decreased 66% < 40% Normal < 30% Protein 5-40 mg/dl increased +/-increased increased Culture negative positive negative +TB Gram stain negative positive negative positive Lumbar Puncture CSF plasma : glucose ratio
Video of Lumbar Puncture • NEJM
Lumbar Puncture References: Attia J, Hatala R, Cook DJ, Wong JG: The rational examination. Does this adult patient have acute meningitis? JAMA 1999;282:175-181. Baraff LJ: Management of fever without source in infants and children. Ann Emerg Med 2000:36:602-614. Manno EM: Subarachnoid hemorrhage. Neurol Clin 2004;22:347-366. Euerle B: Spinal puncture and cerebrospinal fluid examination. In Roberts JR, Hedges JR (eds): Clinical Procedures in Emergency Medicine, 4th ed. Philadelphia, WB Saunders, 2004, pp 1197-1222. Gopal AK, Whitehouse JD, Simel DL, Coery GR: Cranial computed tomography before lumbar puncture: a prospective clinical evaluation. Arch Intern Med 1999;159:2681-2685. Hasbun R, Abrahams J, Jekel J, Quagliarello V: Computed tomography of the head before lumbar puncture in adults with suspected meningitis. N Engl J Med 2001;345:1727-1733. Riordan FAI, Cant AJ: When to do a lumbar puncture. Arch Dis Child 2002;87:235-237. Lavi R, Yernitzky D, Rowe JM, Weissman A, Segal D, Avivi I: Standard vs atraumatic Whitacre needle for diagnostic lumbar puncture: a randomized trial. Neurology 2006;67:1492-1494. Fong B, Van Bendegm J: Lumbar Puncture. In Reichman E, Simon R (eds): Emergency Medical Procedures. New York, McGraw-Hill, 2004, pp 859-880. Deibel M, Jones J, Brown M: Best evidence topic report: reinsertion of the stylet before needle removal in diagnostic lumbar puncture. Emerg Med J 2005;22:46. Thoennisen J, Herkner H, Lang W, Domanovits H, Laggner AN, Müllner M: Does bed rest after cervical or lumbar puncture prevent headache? A systematic review and meta-analysis. Can Med Assoc J 2001;165:1311-1316. Gallagher E, Campbell CG: Lumbar-puncture headache; its prevention and treatment. Lancet 1954;267:678-679. Strupp M, Brandt T: Should one reinsert the stylet during lumbar puncture? N Engl J Med 1997;336:1190. Flaatten H, Thorsen T, Askeland B, et al: Puncture technique and postural postdural puncture headache. A randomized, double-blind study comparing transverse and parallel structure. Acta Anaesthesiol Scand 1998;42:1209-1214. Shah KH, Richard KM, Nicholas S, Edlow JA: Incidence of traumatic lumbar puncture. Acad Emerg Med 2003;10:151-154. Pai SB, Krishna KN, Chandrashekar SS: Post lumbar puncture spinal subarachnoid hematoma causing paraplegia: a short report.. Neurol India 2002;50:367-369.
Central Venous Access Introduction • Central venous lines provide access for blood draws, facilitate administration of fluids or medications, and allow for measurement of cardiac filling pressures. Indications for Procedure • Administration of fluids / medications into the vasculature • Central circulation and intracardiac access • Maintenance of venous access • Hemodialysis and plasmapheresis
Central Venous Access Indications • Administration of agents into the central vasculature • Central venous access is required to administer certain medications, including most vasoactive and/or inotropic agents (i.e., vasopressors such as dopamine and norepinephrine). In addition to expediting delivery of these drugs to the heart and arterial system, central administration decreases the risk of damaging peripheral tissue from the vasoconstrictive effects of the medications. • Patients needing total parenteral nutrition also require central access because the osmolarity of the mixture exceeds what can safely be administered into the peripheral circulation. • Other hyperosmolar agents that are optimally infused through a central line include concentrated potassium solutions, hypertonic saline solutions, certain chemotherapeutic agents, and calcium chloride.
Central Venous Access Indications • Central circulation and intracardiac access • Measurement of central venous filling pressure within the right atrium can be helpful in determining the volume status of a patient and can readily be transduced via a central venous catheter in the internal jugular or subclavian position. • Specialized pulmonary artery (i.e., Swan-Ganz) catheters can be used to measure pulmonary capillary wedge pressure, a means of approximating left-sided filling pressure • Blood drawn from a central catheter can allow the measurement of mixed venous (or central venous) oxygen saturation, often used to estimate cardiac output. • Temporary transvenous pacemakers can be inserted through central venous catheters (more specifically, sheath introducer catheters) to provide a more reliable and comfortable means of pacing than the transcutaneous route.
Central Venous Access Indications • Maintenance of venous access • In acutely unstable patients, peripheral venous access may be inadequate. • Patients requiring multiple medications in drip formulation can quickly run out of access points. • This problem is compounded in a chronically ill patient, who oftentimes has insufficient peripheral access because of frequent blood drawing and peripheral intravenous (IV) line placement. • Central venous catheters provide reliable access for blood drawing and administration of medications, until either peripheral access can be obtained or less venous access is required. • Hemodialysis and plasmapheresis • Emergency or short-term dialysis and plasmapheresis can be performed via special central venous catheters (e.g., Quinton catheters).
Central Venous Access Contraindications • Absolute contraindications • Adequate peripheral IV access: Given the potential for serious morbidity and the high rate of infection associated with central lines, they should be used only when absolutely necessary. • Operator inexperience (unless supervised by an experienced practitioner): Although placement of a central line is a relatively safe procedure in experienced hands, those unfamiliar with the technique should study the protocol beforehand to gain confidence and must be supervised at all times during placement of a line. • Uncooperative patient: • Placement of a central line requires that the patient remain still so that the operator can define the anatomy accurately, concentrate on steps of the procedure, and be vigilant for signs of complications. • Needles, scalpels, and sutures are necessary tools in this task. Patients who are uncooperative have an unacceptably high risk for injury and also expose the operator to increased risk. • Adequate steps must be taken to make the patient comfortable for the length of the procedure before proceeding. • Relative contraindications • Significant bleeding disorder: Coagulopathies and thrombocytopenia increase a patient's risk for bleeding, but iatrogenic hemorrhages are generally mild and do not require transfusions
Central Venous Access Complications • Pneumothorax (PTX) • Catheter/guidewire embolism • Air embolism • Central vein thrombosis • Arrhythmias • Myocardial or central vein perforation • Pericardial tamponade • Infection • Hematoma • Subcutaneous emphysema or fluid infiltration • Arterial puncture and/or laceration
Central Venous Access Catheter selection • A variety of catheters may be used for central venous catheterization; the triple-lumen catheter and the sheath introducer are the most commonly used and are detailed in this chapter. • Triple-lumen catheters are used when central venous monitoring and/or the administration of fluids or medications is clinically indicated. • Triple-lumen catheters should not be started if rapid volume resuscitation is required. Peripheral IV lines with 14-gauge catheters can infuse volume twice as fast as a triple-lumen catheter can.3 If peripheral access is not available and volume infusion is urgent, consider placing a sheath • Flexible catheter of various sizes (7 French, 16 cm is typical). The catheter is typically inscribed with depth markers along its shaft. • Distal, middle, and proximal infusion channels: • The openings of these channels are visible at the distal (internal) tip of the catheter, and each has a labeled port at the proximal (external) end. • In most situations, the middle external port corresponds to the distal channel. • Each channel is usually 16 to 18 gauge in diameter. • Each external port is supplied with a removable end cap. • The middle cap should be removed before line insertion to allow passage of the guidewire.
Central Venous Access The guidewire • The guidewire is used to perform the Seldinger technique • Guidewires are often demarcated with lines every 10 cm to allow estimation of depth of insertion. • Many guidewires have a spring-loaded mechanism on one end that produces a 180-degree bend at the tip of the wire; these are referred to as “J-wires.” • The rounded leading edge of the J-wire allows it to “bounce” off vessel walls, thereby reducing the risk for vessel perforation.3 • A straightener sleeve is included with J-wires. The sleeve facilitates insertion of the wire into the needle hub.
AnatomyCentral Venous Access • Femoral vein • The femoral vein lies within the femoral sheath and courses under the inguinal ligament; it then becomes the external iliac artery. • The vein is located approximately 1 cm medial to the femoral artery. • The femoral nerve is lateral to the vein. • Needle entry occurs 2 to 3 cm inferior to the inguinal ligament, 1 cm medial to the femoral artery pulsation.
AnatomyCentral Venous Access • Internal jugular vein • The internal jugular vein is not visible or palpable • It courses inferiorly between the two heads of the sternocleidomastoid (SCM) muscle and joins the subclavian vein medial to the head of the clavicle.3 • The internal jugular vein travels with the carotid artery and vagus nerve in the carotid sheath. • The internal jugular always lies anterior and medial to the carotid artery. • The right internal jugular is preferable to the left because it lies almost directly above the SVC and provides direct access to the heart should transvenous pacing or pulmonary artery catheterization be required.
AnatomyCentral Venous Access • Subclavian vein • As the subclavian vein crosses the first rib, it lies posterior to the junction between the medial third and lateral two thirds of the clavicle. • Connective tissue fixes the subclavian to the first rib and clavicle, and thus the vein does not collapse in cases of hypovolemia or cardiac arrest. • The subclavian arteries are located posterior to the veins and are separated from them by the scalene muscles. • The domes of the pleurae of the lungs may extend above the first rib on the left but rarely extend this far on the right, and thus the right side is often preferred for line insertion. • Insertion on the right also avoids the risk of damage to the thoracic duct, which is located near the junction of the left subclavian and left internal jugular.
Central Venous Access Procedure • General approach to central venous catheterization: • Obtain consent. • Get all of your supplies ready and get rid of any unnecessary objects. • Make sure the patient is optimally positioned and restrained (chemically or physically, only if necessary). • Sterile gown, sterile drape, hair cover, face mask/shield. • Prep the area with plenty of betadyne. • Drape the area in sterile fashion and make sure you have all of your tools ready, positioned optimally, and in order of use. Flush the catheter with saline. • Infuse plenty of local anesthetic. • Use the finder needle to locate the vein as described in the following sections on specific IV sites.
Central Venous Access Procedure (CONT) • Once venous blood is aspirated with the finder needle, insert the large bore needle at the same site and at the same angle. • Once venous blood is aspirated, grasp the hub of the needle with your non-dominant hand and brace that hand against the patient. • Lower the needle to the angle parallel to the vein and aspirate to reconfirm flow. If in doubt, confirm that the blood is venous by transducing. Remove the syringe while holding the needle in place and quickly feed the guidewire into the needle watching out for ectopy. • Remove the needle over the guidewire and hold it in place with gauze (never let go of the wire!). • Use scalpel to make a 3-4 mm stab through skin and fascia (sharp end away from guidewire).
Central Venous Access Procedure (CONT) • Pass dilator 3-4 cm over guidewire to dilate subcutaneous tissue. • Pass catheter over guidewire which should exit out of the brown port (if using a triple lumen). • Advance the catheter (don't lose the wire) and remove the guidewire. • Aspirate blood and flush each port. • Suture line in place and consider spacer in a small patient. • Stat CXR to rule out pneumothorax and check line placement. • Write procedure note and record procedure for your records and certification.
Central Venous Access Post Procedure Care • Confirmation of line placement • Radiographic confirmation of femoral line placement is not required; however, it may be obtained if the line's position is uncertain. • Correct line placement can be confirmed by return of venous blood during aspiration of the ports. • Dressing changes • To minimize the risk for nosocomial bloodstream infection from central lines, the dressing on each line must be changed every 72 hours, or sooner, if it appears to no longer provide an adequate barrier to entry of organisms. • The old dressing should be removed, the site cleaned with chlorhexidine, and the new sterile dressing placed and dated. • Chlorhexidine has been shown to be superior to ethanol and povidone-iodine solutions in preventing line infections. • Interestingly, changing a line over a wire or starting a line in a new position has been not shown to decrease line infections.
Central Venous Access Removing Central Lines • Always use sterile technique. Sterile gloves, field, and suture removal kit. • Make sure the line is not tunneled and does not have to be taken out by interventional radiology. Procedure: • Place the patient in Trendelenburg (reverse Trendenlenburg for femoral lines) and remove any pillows. • Remove all bandages and gauze. • Cut and remove all suture material being careful to not leave any behind. • Instruct the patient to hum or valsalva while simultaneously and swiftly removing the central line. • Dress the site with sterile gauze and place a Tegaderm or equivalent occlusive dressing on the gauze. • Proper technique is essential to prevent air embolism.
Central Venous Access • Video of Central Line placement • Overview • Femoral • Subclavian
Central Venous Access References: Maki DG: Infections caused by intravascular devices used for infusion therapy: Pathogenesis, prevention, and management. In Bisno AI, Waldvogel FA (eds): Infections Associated with Indwelling Medical Devices, 2nd ed. Washington, DC, ASM Press, 1994, pp 155-205. Doerfler ME, Kaufman B, Goldenberg AS: Central venous catheter placement in patients with disorders of hemostasis. Chest. 1996;110:185-188. Feldman R: Central venous access. In Reichman EF, Simon RR (eds): Emergency Medicine Procedures. New York, McGraw Hill, 2004, pp 314-337. Mickiewicz M, Dronen SC, Younger JG: Central venous catheterization and central venous pressure monitoring. In Roberts JR, Hedges JR (eds): Clinical Procedures in Emergency Medicine, 4th ed. Philadelphia, WB Saunders, 2004, pp 413-446. Maki DG, Ringer M, Alvarado CJ: Prospective randomised trial of povidone-iodine, alcohol, and chlorhexidine for prevention of infection associated with central venous and arterial catheters. Lancet. 1991;338:339-343. Cobb DK, High KP, Sawyer RG, et al: A controlled trial of scheduled replacement of central venous and pulmonary-artery catheters. N Engl J Med. 1992;327:1062-1068. Raad I, Darouiche R, Dupuis J, et al: Central venous catheters coated with minocycline and rifampin for the prevention of catheter-related colonization and bloodstream infections. A randomized, double-blind trial. The Texas Medical Center Catheter Study Group. Ann Intern Med. 1997;127:267-274. O'Grady NP, Alexander M, Dellinger EP, et al: Guidelines for the prevention of intravascular catheter-related infections. Am J Infect Control. 2002;30:476-489. Raad II, Hohn DC, Gilbreath BJ, et al: Prevention of central venous catheter-related infections by using maximal sterile barrier precautions during insertion. Infect Control Hosp Epidemiol. 1994;15:231-238. Merrer J, De Jonghe B, Golliot F, et al: Complications of femoral and subclavian venous catheterization in critically ill patients: a randomized controlled trial. JAMA. 2001;286:700-707. Mansfield PF, Hohn DC, Fornage BD, et al: Complications and failures of subclavian-vein catheterization. N Engl J Med. 1994;331:1735-1738. Sznajder JI, Zveibil FR, Bitterman H, et al: Central vein catheterization: failure and complication rates by three percutaneous approaches. Arch Intern Med. 1986;146:259-261. Randolph AG, Cook DJ, Gonzales CA, Pribble CG: Ultrasound guidance for placement of central venous catheters: a meta-analysis of the literature. Crit Care Med. 1996;24:2053-2058. Abdelkefi A, Torjman L, Ladeb S et al: Randomized trial of prevention of catheter-related bloodstream infection by continuous infusion of low-dose unfractionated heparin in patients with hematologic and oncologic disease. J Clin Oncol. 2005;23:7864-7870. McGee WT, Ackerman BL, Rouben LR, et al: Accurate placement of central venous catheters: a prospective, randomized, multicenter trial. Crit Care Med. 1993;21:1118-1123.
Paracentesis Introduction • Abdominal paracentesis may be performed as a diagnostic or therapeutic intervention. • Removal of ascitic fluid allows diagnosis of new-onset ascites and may be performed to relieve tense abdominal collections in symptomatic patients or in those with refractory ascites. • Most cases of ascites are related to portal hypertension, although a myriad of other conditions may be implicated, such as intra-abdominal neoplasm, tuberculous peritonitis, and pancreatitis.
Paracentesis Indications • Diagnosis of new-onset ascites. • Diagnostic abdominal paracentesis should be performed in patients with new-onset ascites. • Evaluation of the fluid will indicate whether the ascites is due to portal hypertension or another process, such as cancer or intra-abdominal infection.1 • Evaluation for spontaneous bacterial peritonitis (SBP) • Paracentesis may be performed in patients with preexisting ascites to rule out SBP.
Paracentesis Contraindications • Coagulation disorders • Bleeding complications secondary to paracentesis are rare and, when present, are usually mild and self-limited. • Abnormalities of the overlying skin • The paracentesis needle should not pass through areas of cellulitis, engorged veins, or abdominal wall hematomas. • Distended intra-abdominal organs • The risk for iatrogenic injury is increased in patients with distended intra-abdominal organs, such as in the case of bowel obstruction, urinary retention, or pregnancy. • Ultrasound guidance. • Intra-abdominal adhesions and surgical scars • Bowel is often adherent to the peritoneal wall in areas of previous surgery, trauma, or masses, and such adherence contributes to an increased risk for bowel perforation. • An alternative entry site should be selected, or ultrasound guidance should be used, to minimize the risk for bowel injury.
Paracentesis Equipment • Skin-cleansing agent (e.g., chlorhexidine or povidone-iodine) • Sterile gauze • Sterile drape • Sterile gloves • Local anesthetic (e.g., 1% lidocaine) • 5- to 10 mL-syringe with 25- and 22- gauge needles for injection of anesthetic • Needle and catheter assembly • 35- to 60-mL syringe for aspiration of ascitic fluid • High-pressure drainage tubing • Specimen tubes • Evacuated containers (as many as five or more) • Sterile occlusive dressing • Bedside ultrasound machine (optional) • Needle and catheter assemblies
Paracentesis • Intravenous catheters • Two-inch, 18-gauge intravenous catheters may be used. • Two-inch catheters should be used because shorter needles may not be long enough to access the peritoneal cavity. • Intravenous catheters without retractable needles should be used for paracentesis. • The end cap attached to the flash chamber should be removed before the procedure so that a syringe may be attached to allow active aspiration during insertion. • Paracentesis-specific devices • A variety of paracentesis-specific devices are available, but a thorough discussion of each device is beyond the scope of this chapter. • A Caldwell needle assembly is supplied in the Quick-Tap Paracentesis Kit (Kimberly-Clark, Dallas, TX). The assembly includes an 8-French catheter over an 18-gauge × 7½-inch needle with a three-way stopcock and a self-sealing valve. • The assembly supplied in the Saf-T-Centesis Catheter Drainage Tray (Cardinal Health, Dublin, OH) is also a catheter-over-the needle device and includes a retractable intraluminal obturator that theoretically prevents intra-abdominal organ injury, a self-sealing valve, an in-line stopcock, and a pigtail catheter that has multiple distal drainage ports.
Paracentesis Anatomy • The peritoneal cavity extends from the diaphragm superiorly to the pelvic inlet inferiorly. • Relevant anatomic structures • The rectus sheath contains the rectus abdominis muscle and extends from the inferior costal margin superiorly to the symphysis pubis inferiorly. • The inferior epigastric arteries course in an inferior-to-superior direction along the rectus sheath and must be strictly avoided during paracentesis. • The spleen and liver may be enlarged in patients with cirrhosis, and their location should be firmly ascertained (by physical examination or ultrasound) before paracentesis. • Hollow abdominal organs, such as the bowel and urinary bladder, may be pathologically distended (e.g., bowel obstruction or urinary retention) and should be decompressed if necessary before paracentesis. • 2 cm below the umbilicus in the anatomic midline • This site contains the avascular linea alba and is preferred by some clinicians. • Right lower quadrant (RLQ) or left lower quadrant (LLQ), 4 to 5 cm superior and medial to the anterior superior iliac spine
Paracentesis Procedure • Explain the procedure to the patient. • Obtain written informed consent before the procedure. • Discuss the risk for infection, intra-abdominal organ injury, and post-procedure hypotension. • A well prepared, locally numb, and relaxed and cooperative patient is important for success of this procedure. • Prepare monitoring equipment. • If large-volume paracentesis is planned, start an intravenous line and place the patient on a monitor. See Intravenous Cannulation for further details.