Pain Management
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BLBK137-Paul February 20, 2009 13:17 CHAPTER 8 8 Pain management Mark Nichols MD, Glenna Halvorson-Boyd PhD, RN, Robert Goldstein MD, Clifford Gevirtz MD, MPH and David Healow MD LEARNING POINTS r Proper selection of medications and nonpharmacological interventions reduces pain and anxiety and enhances patient satisfaction. r Several effective techniques exist for administration of local cervical anesthesia. Limited data support use of deep injections and adjunctive premedication with nonsteroidal antiinflammatory drugs. r The most common conscious sedation regimen used by North American abortion providers is a combination of fentanyl and midazolam. r Deep sedation and general anesthesia carry important benefits for certain patients, but they require specialized personnel and equipment. Introduction Pain associated with abortion Managing pain associated with abortion procedures is an es- Pain management remains an important challenge in abor- sential goal in the care of patients requesting pregnancy ter- tion practice, although studies suggest that progress in pain mination. Effective methods range from local cervical anes- control has been achieved over time in the USA. In a sur- thesia, with or without supplemental oral or intravenous vey in the late 1970s, 2,299 women having abortions with (IV) medications, to general anesthesia (GA). A number cervical anesthesia were asked to rate their pain as “mild, of factors influence the options available to patients, in- moderate, or severe.” Forty-six per cent called the pain mod- cluding local regulations, safety considerations, facility in- erate, and 32% called it severe. [2] A survey conducted two frastructure and resources, cost, and insurance coverage. decades later of more than 2,000 patients at 12 abortion fa- In the USA, where most abortions occur in freestanding cilities in the USA found that 30% of patients felt no pain, clinics, cervical anesthesia with or without IV conscious 25% mild pain, 29% moderate pain, and 14% severe pain. sedation represents the most common method used [1]. About 80% of patients said the pain was less than or similar On the other hand, in countries where abortions occur to what they expected. [3] primarily in hospital operating rooms, general anesthesia predominates. This chapter explores pain management for surgical abor- Components of pain tion including the anatomy and physiology of pain; the use Abortion-related pain requires stimulation of sensory fibers of local anesthesia, IV sedation, and GA; and challenging that innervate the uterus, the transmission of those impulses pain management cases. The chapter also investigates the re- via afferent pathways to the spinal column and brain, and lationship of psychosocial and emotional issues to abortion- finally, interpretation of the signals as unpleasant by the related pain and describes nonpharmacological techniques higher cortical centers. The cervix and lower uterine seg- to address them. ment are innervated by parasympathetic fibers from S2 to S4, which form a ganglia lateral to the cervix and enter along with the uterine blood vessels at about 3 o’clock and 9 o’clock (Fig. 8.1). The fundus is innervated by sympathetic fibers from T10 and L1 via the inferior hypogastric nerve, Management of Unintended and Abnormal Pregnancy, 1st edition. By M Paul, which enters the uterus at the uterosacral ligaments, as well ES Lichtenberg, L Borgatta, DA Grimes, PG Stubblefield, MD Creinin as via the ovarian plexuses that enter at the cornua. By anes- c 2009 Blackwell Publishing, ISBN: 9781405176965. thetizing the nerve plexuses adjacent to the cervix along the 90 BLBK137-Paul February 20, 2009 13:17 Pain management 91 As these numerous factors suggest, perception of pain is a complex and multidimensional phenomenon. Recognized components of pain include physical (sensory), psycholog- ical (affective, motivational, and interpretive), and social (context and support) features and their constant interplay. As Melzack noted, “The quality of pain experiences must not be confused with the physical event.”[7] Choice of pain control methods Patient preparation for abortion includes providing relevant information for an informed decision about pain manage- ment. This information includes a description of the proce- dure, the range of possible pain experiences, the available options for treatment, and the benefits and risks of each al- ternative. If the patient expresses a strong preference for a Figure 8.1 Innervation of the uterus. Paracervical anesthesia reaches pain management method that the facility does not offer, the nerve plexuses that lie adjacent to the cervix, but not the nerves that then staff should provide her with appropriate referral re- accompany the ovarian vessels at the level of the uterine fundus. sources. Some women prefer local anesthesia for first-trimester aspiration abortion because they want to avoid the consciousness-altering effects of sedation and remain alert lateral aspects at 3 and 9 o’clock as well as the uterosacral during the procedure, thereby quickening their recovery for ligaments, paracervical anesthesia reduces pain from cer- discharge home. In addition, morbid obesity or certain med- vical manipulation, dilation, and to varying degrees, uter- ical conditions may preclude safe administration of IV seda- ine aspiration. Because the anesthetic agent does not reach tion or GA in a nonhospital-based setting. Deeper levels of nerves that accompany the ovarian vessels at the fundus, it sedation, on the other hand, carry benefits for patients who may have less effect on the cramping associated with uterine are having second-trimester abortions, desire to be more re- emptying. [4] laxed or “asleep” during the experience, or whose elevated anxiety may affect their ability to remain still during the pro- cedure. Deeper levels of sedation require more resources, Factors influencing pain including appropriately trained staff and monitoring equip- Numerous patient-related variables are known to influ- ment. Local, state, or provincial regulations may specify the ence pain perception (Table 8.1). Factors associated with in- facility design, equipment, and personnel necessary to offer creased pain include younger age of the patient [2], fewer IV sedation or GA. prior pregnancies [2], history of dysmenorrhea [5], pre- procedure anxiety [5], and depression [4]. History of prior pelvic examination and gestational age of the pregnancy are Local anesthesia not related to an increase in pain [2]. Regarding the proce- dure itself, both shorter procedure time [2] and provider ex- Most first-trimester aspiration abortions in the USA and perience [6] correlate with less pain; the amount of cervical Canada take place at facilities that use local cervical anes- dilation and cannula size are not associated with an increase thesia with or without IV sedation. A 2002 survey of in pain [2]. National Abortion Federation (NAF) provider facilities (n = Table 8.1 Factors that influence abortion-related pain. Increased Pain No Effect on Pain Decreased Pain Younger patient age [2] Prior pelvic examinations [2] Older patient age [2] Fewer prior pregnancies [2] Gestational age [2] More prior pregnancies [2] History of dysmenorrhea [5] Amount of cervical dilation [2] Shorter operative time [2] Preprocedure anxiety [5] Cannula size [2] Increased provider experience [6] Depression [4] BLBK137-Paul February 20, 2009 13:17 92 Chapter 8 Table 8.2 Selected properties of local anesthetic agents. (Adapted with permission from Bonica [9].). Relative Lipid Protein Relative Agent Solubility Binding (%) pKa Potency Comments AMINO ESTERS More allergic reactions; more expensive Procaine (Novocaine R )1 5 8.91 2-Chloroprocaine 1 0 9.1 1 Low pH; more painful to inject (Nesacaine R ) Tetracaine (Pontocaine R )80 858.68 AMINO AMIDES Fewer allergic reactions Lidocaine (Xylocaine R ) 4 65 7.9 2 Least expensive Bupivacaine (Marcaine R )30 958.18 Long-acting Mepivacaine (Carbocaine R ) 1 75 7.6 2 Prilocaine (Citanest R )1.5 55 7.72 364) examined anesthesia preferences for each facility by minute period [11]. Lidocaine has less potential for cardiac determining the method employed for 40 to 100% of first- toxicity than bupivacaine at similar serum levels. trimester abortions. Of the 110 respondents that expressed In general, current commonly employed cervical anesthe- a preference, 46% used cervical anesthesia with or with- sia techniques that involve injections at multiple sites using out oral medications and 33% combined cervical anesthe- standard dose ranges of procaine-analog agents, including sia with IV conscious sedation; the remaining 21% offered bupivacaine, have not been associated with significant side deep sedation or GA. In general, smaller-volume providers effects [12] or toxic serum levels [13]. However in the tended to offer milder forms of anesthesia [1]. A 2007 survey 1970s, Grimes and Cates [14] reported a series of deaths of Planned Parenthood affiliates in the USA found that virtu- from paracervical anesthesia that included overdoses, inad- ally all respondents provided local anesthesia during surgical vertent bolus intravascular injections, and hypersensitivity abortion, and 85% of affiliates reported offering ibuprofen reactions to preservatives. Serum levels of anesthetic agents preoperatively. Two-thirds of the affiliates reported offer- correlate with toxicity and side effects. At low serum con- ing patients the option of IV sedation for pain management centrations of lidocaine, patients may experience tinnitus,