EMERGENCY SEDATION AND PAIN MANAGEMENT - PART 8 pot

The use of a vasoconstrictor such as 0.5% phenyl- ephrine is recommended prior to administration of lidocaine (Fig ure 31-2 ). By increas ing the internal diameter of the nares, vasoconstrictors may make tube passage easier and less painful and may help prevent epistaxis. Although these benefits are theoreti cal only (they are not based on the results of randomized, placebo-controlled trials), the low likelihood of harm associated with the use of vasoconstrictors make this a reasonable strategy. FOLLOW-UP/CONSULTATION CONSIDERATIONS Once the tube has been placed, proper position must be confirmed. Insufflation of air is the most rapid and most commonly used method in the ED, but does not reliably detect whether the tube has advanced past the stomach into the small intestine. Radiographic confirmation is the most definiti ve way to confirm tube position, but is seldom performed solely for the purpose on confirming NG tube position. Other methods of confirmation include aspiration of stomach contents and observing the patient to speak (Table 31-2). Confirming NG tube position by more than one method will help avoid incorrect placement. Once secured, most patients tolerate the NG tube with only minimal dis- comfort. SUMMARY NG tube placement is a very painfu l procedure that is commonly performed in the ED. In nonemergent situations, awake patients should receive topical anes- thesia prior to tube passage. This is best accomplished using 4 ml of 10% preservative-free nebulized lidocaine delivered by facemask or 4.5 ml of 4% preservative-free atomized lidocaine sprayed into the nares (1.5 ml) and pharynx (3.0 ml), accompanied by 2% intranasal lido- caine jelly. The use of a vasoconstrictor such as phen- ylephrine, 0.5%, may help reduce pain and provide prophylaxis against nosebleeds. BIBLIOGRAPHY 1. Binswanger IA, Kral AH, Bluthenthal RN, et al. High prevalence of abscesses and cellulitis among community- recruited injection drug users in San Francisco. Clin Infect Dis 2000;30:579–581. 2. Cullen L, Taylor D, Taylor S, et al. Nebulized lidocaine decreases the discomfort of nasogastric tube insertion: A randomized double-blind trial. Ann Emerg Med 2004;44:131–137. 3. Ducharme J, Matheson K. What is the best topical anesthetic for nasogastric insertion? A comparison of lidocaine gel lidocaine spray and atomized lidocaine. JEmergNurs 2003;29:427–430. 4. Frazee BW, Lynn J, Charlebois ED, et al. High prevalence of methicillin-resistant staphylococcus aureus in emergen- cy department skin and soft tissue infections. Ann Emerg 2005;45:311–320. Table 31-2. Methods to confirm successful NG tube placement Test Finding Comments Radiographic evaluation Tip of the NG tube within the stomach lumen Most definitive method of confirmation Takes time to obtain More expensive than other methods Insufflation of air Rush of air while listening under the left coastal margin with a stethoscope Simple and rapid Does not reliably detect whether the tube has advanced into the small intestine Increased pressure to instilling air suggests tube kinking or malposition Immediate burp suggests esophageal position Aspiration of stomach contents Fluid with a pH less than 4 (has a 95% probability of being in the stomach) Fluid with a pH ! 6 may indicate respiratory tract placement 2% of patients will have an alkaline stomach pH Ask the patient to speak Patient able to speak; inability to speak suggests respiratory tract placement Some small bore tubes may allow the patient to speak despite tracheal placement 202 Procedural Sedation for the Emergency Patient 5. Gallagher JE. Nasogastric tubes: Hard to swallow. Ann Emerg Med 2004;44:138–141. 6. Miller WC, Awe R. Effect of nebulized lidocaine on reactive airways. Am Rev Respir Dis 1975;111:739–741. 7. Murphy EL, DeVita D, Liu H, et al. Risk factors for skin and soft-tissue abscesses among injection drug users: A case-control study. Clin Infect Dis 2001;33:35–40. 8. Nott MR, Hughes JH. Topical anesthesia for the insertion of nasogastric tubes. Eur J Anesthesiol 1995;12:287–290. 9. Singer AJ, Konia N. Comparison of topical anesthetics and vasoconstrictors vs lubricants prior to nasogastric intuba- tion: A randomized controlled trial. Acad Emerg Med 1999;6:184–190. 10. Singer AJ, Richman PB, Kowalska A, et al. Comparison of patient and practitioner assessments of pain from commonly performed emergency department procedures. Ann Emerg Med 1999;33:652–658. 11. Specktor M, Kaplan J, Kelley J, Wheary J, Dalsey W. Nebulized or sprayed lidocaine as anesthesia for nasogas- tric intubations. Ann Emerg Med 2000;7:406–408. 12. Wolfe TR, Fosnocht DE, Linscott MS. Atomized lidocaine as topical anesthesia for nasogastric tube placement: A randomized double-blind placebo-controlled trial. Ann Emerg Med 2000;35:421–425. Sedation for Brief Surgical Procedures 203 SECTION 4. TOPICAL, LOCAL, AND REGIONAL ANESTHESIA APPROACH TO THE EMERGENCY PATIENT 32 Selected Topical, Local, and Regional Anesthesia Techniques Douglas C. Dillon and Michael Gibbs SCOPE OF THE PROBLEM History PAIN CONSIDERATIONS AND MANAGEMENT Topical Intradermal Regional Blocks Digital Nerve Block General Anatomy Distribution of anesthesia Technique Transthecal Digital Nerve Block General Anatomy Distribution of anesthesia Technique Pitfalls Hand Block General Ulnar Nerve Block Anatomy Distribution of anesthesia Technique Pitfalls Median Nerve Anatomy Distribution of anesthesia Technique Pitfalls Radial Nerve Anatomy Distribution of anesthesia Technique Pitfalls Ankle Block General Sole of the foot Dorsum of the foot 205 Deep Peroneal Nerve Anatomy Distribution of anesthesia Technique Pitfalls Posterior Tibial Nerve Anatomy Distribution of anesthesia Technique Superficial Nerves of the Ankle General Superficial Peroneal Anatomy Distribution of anesthesia Technique Sural Nerve Anatomy Distribution of anesthesia Technique Saphenous Nerve Anatomy Distribution of anesthesia Technique Pitfalls Facial Blocks General Supraorbital and Supratrochlear Nerves Anatomy Distribution of anesthesia Technique Infraorbital Nerve Anatomy Distribution of anesthesia Technique Mental Nerve Block Anatomy Distribution of anesthesia Technique FOLLOW-UP/CONSULTATION CONSIDERATIONS BIBLIOGRAPHY SCOPE OF THE PROBLEM History Prior to the late nineteenth century, local pain control for lacerations and fractures was only achieved by minimizing the pain response centrally, typically with opioids or alcohol. In 1860, cocaine was isolated by Albert Neimann and later refined into a local anesthetic for ocular surgery by Carl Koller in 1884. Within a year, William Halsted and Richard Hall reported the use of cocaine in performing the first successful nerve block of the infraorbital plexus. The two major drawbacks to cocaine – toxicity and addiction – provided the drive to search for alternative anesthetics. In 1904, Alfred Einhorn discovered novocaine, which became the local anesthetic of choice for 30 years. The limitations of novocaine or procaine, a short duration of action and high rate of allergic reactions, led to the 206 Topical, Local, and Regional Anesthesia Approach to the Emergency Patient search for a more ideal local anesthetic. In 1934, Nils Lo ¨ fgren and Bengt Lundquist produced what has come to be known as lidocaine. In the twenty-first century, a multitude of anesthetic options are available (Tables 32-1 and 32 -2 ), allowing the practitioner to choose topical, local, or regional anes- thesia based on wound/fracture location, depth of injury, patient age, patient compliance, and preference of the patient. Emergency anesthesia and analgesia providers should be well versed in anesthetic techniques for fracture reduction, laceration repair, and dermal instrumentation. PAIN CONSIDERATIONS AND MANAGEMENT Adequate local anesthesia is not difficult to obtain and may be gained by topical, local, or regional anesthesia. The amide and ester local anesthetics work by reversibly binding to sodium channels. When applied to nerve tissues, these agents inhibit the propagation of nerve impulses. The smaller nerve fibers are the first fibers to be affected causing a reduction in pain and temperature sensation followed by loss of touch, deep pressure sen- sation, and finally motor function. When choo sing a local anesthetic agent, three factors guide the appropriate selection: onset of clinical effects, duration of clinical effects, and agent toxicity (Tables 32-1 and 32-2 ). Topical Topical anesthetics can be broken into two categories: those used on intact skin prior to dermal instrumenta- tion and those used on open skin for pain control or prior to wound repair. Eutectic mixture of local anesthetics (EMLA) was the first topical anesthetic for dermal instrumentation found to be as efficacious as infiltration of local anesthesia. EMLA is an alkaline mixture of lidocaine and prilocaine applied as a cream to intact skin. At a high pH, both agents exist in the nonionized form, allowing rapid diffusion through membranes. Although EMLA is effective, the slow onset of clinical effects requires at least 40 min of application time prior to the procedure. Liposome-encapsulated tetracaine, liposome-encapsulated lidocaine, and tetracaine have all been compared to EMLA and are found to be equally efficacious, with liposome- encapsulated lidocaine having the shortest onset of action (Table 32-1). The first topical anesthetic used on an open dermis was a tetracaine, adrenaline, and cocaine (TAC) mixture. The Table 32-1. Topical anesthetic agents Topical anesthetics Application Time to onset Intact dermis EMLA(lidocaine and prilocaine) Thick layer applied over the area to be anesthetized 60 min Tetracaine (Ametop) 1 g applied over the 30 min liposome encapsulated area to be anesthetized tetracaine (LET) Liposome encapsulated 2.5 g applied over the 30–60 min lidocaine (LMX-4) area to be anesthetized Open dermis Lidocaine, epinephrine, 1–3 ml applied directly 10–30 min or tetracaine (LET) into the wound until wound edges blanche Mucosa ‘‘ZAP’’ 1–3 ml applied over the 5–10 min or tetracaine (LET) area to be anesthetized until wound edges blanche Benzocaine Spray over the area 30 s to 1 min to be anesthetized Viscous lidocaine Apply with cotton swabs 2–5 min over the area to be anesthetized Topical, Local, and Regional Anesthesia 207 cocaine component of this combination has more recently been replaced with lidocaine owing to the potential for central nervous system and cardiovascular toxicity. A lidocaine, epinephrine, and tetracaine (LET) mixture is usually synthesized by a local hospital pharmacy in accor- dance with theconcentration preferences oflocalclinicians. Intradermal Achieving adequate anesthesia for laceration repair by subdermal injection is the mainstay of local anesthesia in the emergency department. A local anesthetic may be directly infiltrated into most clean lacerations or deli- vered as a field block for more contaminated wounds. The proper plane of injection is just beneath the dermis in the subcutaneous tissue. Avoid injection directly into the dermis as this causes considerably more pain. Injecting the agent slow ly, with a small-gauge needle will also decrease patient discomfort. The selection of an anesthetic agent should be guided by three factors: onset of action, duration of action, and toxicity. The onset of action of a local anesthetic is a function of the pKa (the pH at which 50% of the drug is ionized and 50% of the drug is nonionized). If the ambient pH is higher than the pKa of the agent; a higher percentage of the drug will be nonionized. Nonionized drug diffuses more rapidly across lipid membranes; thus, the onset of action is shorter. Although clinicians typically will not select an anesthetic based on the pKa of the agent, alkalinization of the drug is a useful and straightforward method for decreasing the onset of action and improving patient comfort. This can be done by adding standard strength sodium bicarbonate to the anesthetic at a ratio of 1:10, bicarbonate to anesthetic. Anesthetic duration of action has important clinical implications. Although lidocaine co ntinues to be the anesthetic of choice, owing to its bioavailability, rapid onset of clinical effects, and low allergenic profile, many providers use bupivacaine for enhanced postprocedure pain control owing to the longer duration of clinical effects. The toxicity of local anesthetics occurs with sodium channel blockade in non target tissues, primarily the brain and heart. There is a dose-related clinical progres- sion of local anesthetic toxicity from subtle neurological symptoms to refractory seizures and ultimately, cardio- vascular collapse (Figure 32-1). Table 32-2. Local anesthetic agents Agent Lipid solubility a Protein binding b Duration (min) Onset c (min) Max dose mg/kg (w/epi) Amides Bupivacaine High High 200+ 10–15 3 (3.5–5) Lidocaine Medium Medium 30–60 5 4.5 (7) Mepivicaine Low Low 45–90 3 4 Prilocaine Medium Medium 30–90 5 5 Ropivacaine Medium Medium 200+ 5–15 3 Esters Procaine Low Low 40 15–20 7 Chloroprocaine Low Low 45 5 8 Tetracaine High High 200 15 1.5 Alternatives for patients with reactions to amides and esters (1%) Diphenhydramine d 25–25 (0.9%) Benzyl alcohol e w/ epi 15–25 Notes: a Lipid solubility determines the potency of the anesthetic with the more lipophilic anesthetics having enhanced potency compared to less lipophilic agents. b The more an anesthetic is bound to proteins, generally the longer duration of action. c The onset of action of an anesthetic is determined by the total dose of anesthetic given and the pK a of the drug. d Diphenhydramine solution comprised of 4:1 normal saline and 5% diphenhydramine. e Benzyl alcohol solution comprised of 0.2 ml of epinephrine 1:1,000 to a 20-ml vile of normal saline containing benzyl alcohol 0.9%. 208 Topical, Local, and Regional Anesthesia Approach to the Emergency Patient Allow 5–10 min for full anesthesia with lidocaine and 15–20 min with bupivacaine injection. If this procedure does not provide complete anesthesia, more anesthetic may be needed by either reapplication of the digital nerve block or performance of a transthecal digital nerve block. Transthecal Digital Nerve Block General The transthecal approach utilizes the flexor tendon sheath to apply anesthetic to the digital nerves (Figure 32 -3). This procedure can be performed in addition to, or as an alternative to, a digital nerve block. Anatomy The flexor tendon sheath encases the flexor tendon on the palmar side of the digit. The sheath begins just proximal to the palmar crease of the hand. Distribution of anesthesia The transthecal digital nerve block provides anesthesia to the entire digit. Technique Identify the palmar crease along the palmar aspect of the hand. Have the patient flex the finger to be blocked if possible to improve visualization of the flexor tendon. At the level of the distal palmar crease, puncture the skin at a 45  angle until the ‘‘pop’’ of the flexor tendon sheath is felt. If this sensation is not detected, continue to insert the needle until the needle contacts bone. Withdraw the needle 2–5 mm and inject 2–3 ml of anesthesia. When the needle is in the flexor tendon sheath, the anesthesia should flow easily. Allow 5–10 min for full anesthesia with lidocaine or 15–20 min with bupivacaine. Pitfalls Not performing a transthecal block with a failed dorsal digital block. Hand Block General These blocks are excellent blocks for lacerations, puncture wounds, or bony dislocations of the hand. They can be used in part or in combination to provide anesthesia to the entire hand. When performing a complete hand block, the ulna, median, and radial nerves should be blocked. Ulnar Nerve Block Anatomy Identify the flexor carpi ulnaris and ulnar artery by having the patient deviate their hand in an ulnar direction at the wrist (giving the thumbs up) (Figure 32-4). The flexor carpi ulnaris is the most medial (ulnar) tendon. The ulnar artery can be palpated just medial and dorsal to the tendon. The ulnar nerve lies between the ulnar artery and the flexor carpi ulnaris tendon. The ulnar nerve innervates Figure 32-2. Digital. Anesthetic placed as shown blocks both the dorsal (a) and palmar (b) digital nerves, ensuring circumferential anesthesia of the finger. In using the sequence shown, the prior injection provides relief from the injection to follow. (For color reproduction, see Color Plate 32-2.) 210 Topical, Local, and Regional Anesthesia Approach to the Emergency Patient the flexor pollicis brevis, abductor pollicis, palmaris brevis, abd uctor digiti minimi, flexor digiti minimi opponens digiti minimi, the medial two lumbicals, and all the interossei muscles. Distribution of anesthesia This procedure provides anesthesia to the entire fifth digit, half of the fourth digit, and the medial aspect of the hand and wris t (Figu res 32-5 and 32-6 ). Technique The surgical field should be prepared just proximal (1–2 cm) to the most distal wrist crease. Raise a wheal of anesthetic in the subcutaneous space and insert the needle under the flexor carpi ulnaris 1 cm just palmar to the ulnar styloid. If blood is aspirated, withdraw the needle a few millimeters and aspirate again, the nerve is more superficial from the injection point. Inject approximately 5–7 ml of anesthetic. To block the cutane ous branches of the ulnar nerve, inject 3–5 ml of anesthetic just above the tendon of the flexor carpi ulnaris. Pitfalls If bone is struck, withdraw the needle and direct it more palmar. Median Nerve Anatomy Identify the flexor carpi radialis and the palmaris longus tendons at the palmar aspec t of the wrist (Figu re 32-7 ). Figure 32-3. Thecal. The MCP joint and metacarpal head are palpated, and the point of injection is estimated as just proximal to the joint in the midline (at the proximal palmar crease). A 25-gauge needle is advanced at 45  , tip distal, through the tendon/mesotendon complex (shown in blue) until bone is encountered. Anesthetic is injected and the needle is slowly withdrawn. Loss of resistance locates the needle tip within the mesotendon, where 2 ml of anesthetic is injected. Diffusion of anesthetic out of the mesotendon blocks adjacent palmar digital nerves. (For color reproduction, see Color Plate 32-3.) Topical, Local, and Regional Anesthesia 211 The palmaris longus, if present, is usually the more prominent of the two tendons and can be identified by having the patient flex at the wrist. To help identify the flexor carpi radialis, have the patie nt flex and abduct the wrist. The median nerve is lateral (radial) to the pal- maris longus tendon and between the palmaris longus and the flexor carpi radialis. The median nerve provides motor innervation to the thenar muscles (abductor pollicis brevis, flexor pollicis brevis, opponens pollicis) and the first and second lumbricals. Distribution of anesthesia The median nerve provides sensation to the lateral three and a half digits except the dorsal aspect of the thumb, and the corresponding area of the palm (Figures 32-5 and 32-6). Technique The surgical field should be prepared across the entire volar surface of the wrist at the proximal palmar crease. Raise a wheal of anesthetic in a subcutaneous space and insert the needle until it pierces the deep fascia. Figure 32-4. Ulnar. Illustration A demonstrates the technique for identifying the flexor carpi ulnaris (f.c.u.) tendon. During ulnar deviation and flexion of the wrist, both the FCU and the pisiform to which it attaches are palpated. In C, the lateral approach to the ulnar nerve is shown. The needle is oriented horizontally beneath the FCU and inserted to a depth of 1.0–1.5 cm, where a 3–5 ml depot of anesthetic follows negative aspiration. B shows the subcutaneous field block of the dorsal ulnar nerve branches, extending from the site of insertion of the ulnar block to the midline posterior wrist. (For color reproduction, see Color Plate 32-4.) 212 Topical, Local, and Regional Anesthesia Approach to the Emergency Patient [...]... 19 98; 25:1 58 162 7 Zempsky WT, Cravero JP, and the Committee on Pediatric Emergency Medicine and Section on Anesthesiology and Pain Medicine Relief of pain and anxiety in pediatric patients in emergency medical systems Pediatrics 2004;114:13 48 1356 8 Zempsky WT Topical anesthetics for procedural pain in children What does the future hold? Curr Drug Ther 2006;1: 283 –290 34 Regional Anesthesia for Adult and. .. 2006;29(S):1433–14 58 3 Kleiber C, Harber DC Effects of distraction on children’s pain and distress during medical procedures: A metaanalysis Nurs Res 1999; 48: 44–49 4 Menke E School-aged children’s perception of stress in the hospital Child Health Care 1 981 ;9 :80 86 5 Young KD Pediatric procedural pain Ann Emerg Med 2005;45:160–171 6 Zempsky WT, Ashburn MA Iontophoresis: Noninvasive drug delivery Am J Anesthesiol 19 98; 25:1 58 162... OF PROBLEM CLINICAL ASSESSMENT PAIN MANAGEMENT The Environment Nonpharmacologic Techniques Anesthetics SUMMARY BIBLIOGRAPHY SCOPE OF PROBLEM Pain relief for children in the emergency department (ED) is an essential component of care Improvements in the recognition and treatment of pain in children have led to changes in the approach to pain management for acutely ill and injured pediatric patients... analgesia during the acute management of fractures and dislocations should be a high priority for the emergency physician By achieving this 230 goal, the clinician will alleviate patient pain and anxiety, increase the likelihood of successful injury management, and enhance patient and provider satisfaction CLINICAL ASSESSMENT In assessing which pain and/ or sedation modality best meets the patient’s needs,... will increase patient and parent satisfaction, decrease stress and anxiety, and decrease the overall incidence of patient pain BIBLIOGRAPHY 1 Blount RL, Piira T, Cohen LL Management of pediatric pain and distress due to medical procedures In Handbook of pediatric psychology, 3rd edition, ed MC Roberts New York: Guilford Press, 2003 2 Infusion Nurses Society, Infusion Nurses Society Standards of Practice... Anesthesia Approach to the Emergency Patient Figure 3 2-1 7 Insertion of needle for infraorbital nerve block (For color reproduction, see Color Plate 3 2-1 7.) Figure 3 2-1 8 Insertion of needle for mental nerve block (For color reproduction, see Color Plate 3 2-1 8. ) Topical, Local, and Regional Anesthesia 223 Distribution of anesthesia Distribution of anesthesia Blocking both the supraorbital and supratrochlear... nerve (deep and superficial peroneal, tibial, and sural nerves) and one cutaneous branch of the femoral nerve (saphenous nerve) (Figure 3 2 -8 ) This is an excellent block to use as in combination or in part for lacerations, fracture reductions, and exploring wounds Although there is some overlap, sensory innervation in the foot can be broken down into posterior and anterior nerves The tibial and sural nerves... CONSIDERATIONS FOLLOW-UP/ CONSULTATION CONSIDERATION BIBLIOGRAPHY SCOPE OF THE PROBLEM Fracture and dislocation reduction procedures are common in emergency and acute care populations, particularly in the emergency department (ED) These procedures cause considerable patient discomfort and are often accomplished without the assistance of an orthopedist Achieving adequate analgesia during the acute management. .. is certainly evidence that inadequate pain control can have long-term negative implications for children Neonates who undergo procedures with inadequate analgesia have long-standing alterations in their response to and perceptions of painful experiences Inadequate pain control during oncology procedures leads to significantly increased pain scores for subsequent painful procedures Posttraumatic stress... their pain and distress Ideally, each child should be placed in a private room This room should provide a child-friendly, calming environment Colorful walls, pictures on the ceiling, and a collection of toys and games will minimize fear induced by this strange setting A child life specialist based in the ED enhances the impact of a comprehensive effort to reduce pain by (a) decreasing anxiety and pain . long-standing alterations in their response to and perceptions of painful experiences. Inadequate pain control during oncology procedures leads to significantly increased pain scores for subse- quent. clinical effects, and agent toxicity (Tables 3 2-1 and 3 2-2 ). Topical Topical anesthetics can be broken into two categories: those used on intact skin prior to dermal instrumenta- tion and those used. the dorsal lateral half of the hand and the dorsal aspect of the thumb (Figu res 3 2-5 and 3 2-6 ). The radial nerve provides no motor innervation to the intrinsic muscles of the hand. The radial nerve provides