Chronic Cancer Pain Management
Pain is categorized by the International Association for the Study of Pain as “an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage.”1 Accordingly, pain is a complex subjective phenomenon that makes it difficult to qualitatively and quantitatively assess in individuals. Nonetheless, pain is usually described as acute or chronic, and can result from either nonmalignant or malignant causes.
Acute pain is a “wake up” call from nature, signaling us that there is something wrong. It is typically categorized as mild, moderate, or severe. Acute pain is also associated with physiologic changes consistent with sympathetic nervous system activation (e.g., sweating, tachycardia, papillary changes) similar to that seen with acute anxiety. With acute pain, we can expect that the pain will improve when the cause of the acute injury is removed and the healing process proceeds unabated. A classic example would be incisional pain which is characteristically worse during the early postoperative period but steadily improves day by day until complete cessation.
Chronic pain, however, cannot be rationalized as part of the healing process. It has been described as a disease state unto itself and is associated with a significant biopsychosocial component (e.g., depression, sleep disorders, functional impairment). Before a pain disorder can be appropriately treated, the clinician must have an understanding of its causes(s) and its natural history. Likewise, suitable subjective and objective pain assessments must be made that employ appropriate evaluative tools prior to formulating a treatment plan.
The following case study illustrates the use of a problem-based learning (PBL) format2 as it is applied to an individual experiencing chronic cancer pain. The overall objectives include: describing the differences between acute nonmalignant and chronic malignant pain, recognizing the importance of employing the appropriate tool(s) in pain measurement, and developing selected pain management and symptom-control strategies. This approach will allow the reader to apply the principles outlined here to any clinical situation in an effort to resolve patient problems and develop a management plan. There are five basic components to the PBL: identifying the problems, formulating hypotheses for the problems, articulating patient goals, creating solutions for problem resolution, and preparing the management plan.
Chief Complaint and Present Illness
Johnny Hert is a 63-year-old man who presented to a family practice center affiliated with a large tertiary-care academic medical center. His chief complaints were: “I’m having belly pain and my stomach looks like it is getting big. I feel so tired all the time, and I’m having trouble urinating and it hurts whenever I finish.” He was in his usual state of health until approximately one month ago when he developed upper abdominal pain and constipation. He had also lost about 18 pounds during the past two to three months. During a recent visit to his family physician, he was noted to have a tender liver edge on physical examination and elevated liver function tests. He was admitted from the clinic to University Hospital for a diagnostic workup of his abdominal complaints and abnormal laboratory findings.
Usual childhood illnesses. No past surgeries. Family History: His father died at age 72 from prostate cancer. His mother died at age 64 from a CVA. One younger brother (age 55) and older sister (age 67) are alive and well. One uncle died at age 80 from rectal cancer. Social History: Retired manual laborer from a local faucet factory. He smoked one and onehalf ppd for 50 years and for the past two years smoked one ppd. He drinks an occasional beer. He is a widower (wife died of breast cancer four years ago). No medications. No known drug allergies but codeine causes nausea.
Pertinent Physical Examination Findings
Appearance, the patient is a cachectic unshaven man
Height, 173cm (5 ft 8”)
Weight, 66 kg (145.2 lbs)
Blood Pressure, 130/76
Respiratory Rate, 24
Temperature, 37.1oC (98.8oF)
Head, Eyes, Ears, Nose, Throat (HEENT), Scleral icterus
Neck, 3+ adenopathy
Chest, crackles throughout
Abdomen, Moderately distended, liver edge 3 cm below the right costal margin, liver span 10 cm; (+) fluid wave; no palpable masses;
Lab Results, AST 20 IU/L, ALT 15 IU/L, GGT 1837 IU/L, alkaline phosphatase 952 IU/L, total bilirubin 1.4 mg/dl, direct bilirubin 0.8 mg/dl, PT–12 sec, aPTT–19.5 sec.
Abdominal x-ray, proctoscopy, flexible sigmoidoscopy, and barium enema are nondiagnostic. Liver-spleen scan shows portal vein hypertension. Peritoneal fluid is positive for adenocarcinoma cells. Abdominal CT scan reveals a mass in tail of pancreas, probable metastasis and/or node around head of pancreas with obstruction of biliary tree and portal vein thrombosis, stomach compressed by ascites.
Inoperable adenocarcinoma of the pancreas.
The patient was begun on morphine sulfate (2mg SQ Q 4 H PRN) for mild aching stomach and costovertebral angle pain along with temazepam (15mg po Q HS PRN) for sleep. The morphine relieved his discomfort for about four to six hours. Respiratory function was unaffected and the patient remained fully conscious, with no complaints of increased drowsiness. However, the dose of morphine was eventually escalated uneventfully to 3mg SQ Q 4 H PRN over four days for worsening pain.
If we follow the PBL format outlined in the case study, the first step is to identify the patient’s pertinent problems and generate a problem list. The patient is a middle-aged retired man who presented to a primary care clinic with complaints of abdominal pain and swelling, constipation, voiding difficulty, weight loss, and lassitude. Additionally, he was noted to have several abnormal laboratory test results. He has a significant smoking history (>75 pack per year history) and occasionally drinks alcohol. He presently takes no medication and he experienced nausea with codeine. Physical examination findings reveal jaundice, head and neck lymphadenopathy, hepatomegaly and ascites. Liver function tests are elevated along with abnormal radiologic tests and peritoneal fluid cytology.