Page 702 - Hematology_ Basic Principles and Practice ( PDFDrive )

594 Part V Red Blood Cells

examination. Changes in steady-state Hb values, sickled cells on analgesia, it must be remembered that individuals with SCD metabo-
blood smear, WBC counts, and so on are not reliable indicators. lize narcotics rapidly. 129
Numerous laboratory tests, leukocytosis, D-dimer fragments of The pain pathway should be targeted at different points with
fibrin, and markers of platelet activation have been found to lack different agents, avoiding toxicity with any one class (Table 42.7).
specificity as indicators of acute vasoocclusion. Often patients can tell The mainstays are nonsteroidal antiinflammatory drugs (NSAIDs),
if they are having a typical pain crisis or something more sinister. It acetaminophen, and opioids. NSAIDs can be used to control mild
is thus good practice to ask the patient if it feels like the usual to moderate pain and may have an additive role in combination with
pain-crisis pain. opioids for severe pain. The most potent NSAID is ketorolac.
Initial medical assessment should focus on detection of triggers or NSAIDs should be used with caution in those with a history of peptic
medical complications requiring specific therapy, which include ulcer, renal insufficiency, asthma, or bleeding tendencies. Within
infection, dehydration, acute chest syndrome (fever, tachypnea, chest limits, use the agents that the patients know work for them and avoid
pain, hypoxia, and chest signs), severe anemia, cholecystitis, splenic meperidine (Demerol), which should only be used under very excep-
128
enlargement, neurologic events, and priapism. Pain management tional circumstances. Sedatives and anxiolytics alone should not be
should be aggressive to make the pain tolerable and enable patients used to manage pain because they can mask the behavioral response
to attain maximum functional ability. To make the patient pain free to pain without providing analgesia.
is an unrealistic goal and risks oversedation and hypoventilation, Treatment of persistent or moderate to severe pain should be based
128
which must be avoided. A pain chart should be started and analgesia on increasing the opioid strength or dose. One approach is to
titrated against the patient’s reported pain together with medical administer morphine 0.1 mg/kg intravenously or subcutaneously
assessment of the patient’s overall clinical status, paying particular every 20 minutes until pain is controlled. The patient should be
attention to avoiding oversedation. When clinicians consistently checked at 20-minute intervals for pain; respiratory rate, depth, and
observe a disparity between patients’ verbal self-report of their pain quality; and sedation until the patient is stable with adequate pain
and their ability to function, further assessment should be performed control. Subsequently, the patient should receive a maintenance dose
to ascertain the reason for disparity. Patients are often undertreated of 0.05–0.15 mg/kg intravenously or subcutaneously every 2–4
for pain because many physicians and other health care providers are hours. A rescue dose of 50% of the maintenance dose can be consid-
overly concerned with the potential for addiction. Undertreatment ered on an as-needed basis every 30 minutes for breakthrough pain.
of pain is no more desirable than overtreatment and oversedation; During maintenance with opioids, pain control; respiratory rate,
undertreatment can prolong the duration of a painful episode and depth, and quality; and oxygen saturation should be monitored
can poison the relationship between the patient and the health care approximately every 2 hours. If respiratory depression is noted, omit
system. In assessing patient responses to conventional doses of the maintenance dose of morphine. For severe respiratory depression

TABLE Recommended Dose and Interval of Analgesics Necessary to Obtain Adequate Pain Control in Patients With Sickle Cell
42.7 Disease
Dose/Rate Comments
Severe to Moderate Pain
Morphine Parenteral: 0.1–0.15 mg/kg every 3–4 h Drug of choice for pain; lower doses in elderly adults and
Recommended maximum single dose, 10 mg infants and in patients with liver failure or impaired
PO: 0.3–0.6 mg/kg every 4 h ventilation
Meperidine Parenteral: 0.75–1.5 mg/kg every 2–4 h Increased incidence of seizures; avoid in patients with renal
Recommended maximum dose, 100 mg or neurologic disease and those who receive MAOIs
PO: 1.5 mg/kg every 4 h
Hydromorphone Parenteral: 0.01–0.02 mg/kg every 3–4 h
PO: 0.04–0.06 mg/kg every 4 h
Oxycodone PO: 0.15 mg/kg/dose every 4 h
Ketorolac IM: Adults: 30 or 60 mg initial dose followed by 15–30 mg; Equal efficacy to 6 mg MS; helps narcotic-sparing effect;
children: 1 mg/kg load followed by 0.5 mg/kg every 6 h not to exceed 5 days; maximum, 150 mg first day,
120 mg maximum on subsequent days; may cause
gastric irritation
Butorphanol Parenteral: Adults: 2 mg every 3–4 h Agonist–antagonist; can precipitate withdrawal if given to
patients who are being treated with agonists
Mild Pain
Codeine PO: 0.5–1 mg/kg every 4 h Mild to moderate pain not relieved by aspirin or
Maximum dose, 60 mg acetaminophen; can cause nausea and vomiting
Aspirin PO: Adults: 0.3–6 mg every 4–6 h; children: 10 mg/kg every 4 h Often given with a narcotic to enhance analgesia; can
cause gastric irritation; avoid in febrile children
Acetaminophen PO: Adults: 0.3–0.6 g every 4 h; children: 10 mg/kg Often given with a narcotic to enhance analgesia
Ibuprofen PO: Adults: 300–400 mg every 4 h; children: 5–10 mg/kg every Can cause gastric irritation
6–8 h
Naproxen PO: Adults: 500 mg/dose initially and then 250 every 8–12 h; Long duration of action; can cause gastric irritation
children: 10 mg/kg/day (5 mg/kg every 12 h)
Indomethacin PO: Adults: 25 mg every 8 h; children: 1–3 mg/kg/day given 3 Contraindicated in psychiatric, neurologic, renal diseases;
or 4 times high incidence of gastric irritation; useful in gout
IM, Intramuscular; MAOI, monoamine oxidase inhibitor; MS, morphine sulphate; PO, oral.
Adapted from Charache S, Terrin ML, Moore RD, et al. Effect of hydroxyurea on the frequency of painful crises in sickle cell anemia. Investigators of the Multicenter
Study of Hydroxyurea in Sickle Cell Anemia. N Engl J Med 332:1317, 1995.