Critical Cancer Complications (Knowledge=Power)

[Donna G]

Nursing: Volume 35(1) January 2005 pp 58-63

Managing three critical cancer complications

HELD-WARMKESSEL, JEANNE RN, AOCN®, APRN, BC, MSN

A PATIENT WHO HAS CANCER is at risk for various emergencies related to the malignancy itself, metastasis, a paraneoplastic process, or even anticancer therapy. These emergencies can range from mild to life threatening, but what they have in common is the need for prompt attention to prevent permanent injury. Presenting a case study, I'll detail three such critical complications: syndrome of inappropriate antidiuretic hormone (SIADH), spinal cord compression (SCC), and anaphylactoid reaction, and I'll explain what to do when a patient develops them.

SIADH: Water, water, everywhere

Gloria Albanez, 55, comes to the emergency department (ED) after coughing up blood at home. She tells you she's been excessively tired and she's had headaches and gained 20 pounds (9 kg) over the past 2 months. Her husband adds that she hasn't been herself lately, acting confused, irritable, and forgetful. She has a 30 pack-year history of cigarette smoking.

Stat blood work reveals only one abnormal result, a serum sodium level of 125 mEq/liter (normal, 136 to 145 mEq/liter), and a chest X-ray shows a large central right lung lesion with a pleural effusion. The attending physician orders a follow-up serum osmolality test. The results are 275 mOsm/kg water (normal, 280 to 295 mOsm/kg), so he makes a presumptive diagnosis of small cell lung cancer (SCLC) with SIADH and rule out metastasis. Although SIADH is uncommon, it's often associated with SCLC. (See SIADH: Fluid regulation gone awry for details.)

Recognizing the signs, reaching a diagnosis

Hyponatremia is one of the hallmarks of SIADH, and Mrs. Albanez has some of the classic signs and symptoms: headache, change in mental status or personality, lethargy, irritability, and weight gain. Other signs and symptoms include oliguria, muscle or abdominal cramps, poor appetite, nausea, vomiting, and diarrhea.

Serum and urine sodium and osmolality levels can confirm the diagnosis of SIADH with the following results:

* serum sodium less than 130 mEq/liter

* serum osmolality less than 280 mOsm/kg water

* urine sodium greater than 20 mEq/liter

* urine osmolality greater than 100 mOsm/kg water

* urine osmolality greater than serum osmolality.

The degree of hyponatremia caused by dilute plasma and the speed with which hyponatremia develops determine the severity of signs and symptoms in SIADH. A rapidly falling sodium level can cause life-threatening symptoms, but a patient with chronic low-grade hyponatremia may not develop signs and symptoms unless her sodium level drops below 125 mEq/liter.

With hyponatremia, water shifts from the extracellular fluid space to the intracellular space. As brain cells swell, the patient develops progressive neurologic signs and symptoms, including ataxia and tremors and, as sodium levels continue to decrease, seizures and coma. She can die if her sodium level drops below 115 mEq/liter.

Safety, education, and treatment

Your priorities when caring for a patient with SIADH are keeping her safe and administering treatments to increase her serum sodium levels and reduce intracellular water. Here's what to do:

* Educate her about the need for fluid restriction. She must limit fluid intake to less than 1 liter/day to let serum sodium levels increase toward normal. Fluid restriction takes 3 to 10 days to start working and is continued until antineoplastic therapy resolves the cause of SIADH.

* Closely monitor her fluid status by measuring intake and output and daily weights.

* Assess her neurologic status to monitor for improvement, deterioration, or new problems.

* Administer medications as ordered. Antineoplastic therapy helps manage SIADH by destroying the SCLC cells that produce ectopic antidiuretic hormone (ADH). Demeclocycline, 600 to 1,200 mg/day, may be used with or without fluid restriction to treat moderate SIADH (serum sodium 115 to 125 mEq/liter). An antibiotic, demeclocycline limits the ADH effect on the distal renal tubules so the kidneys can excrete water. Adverse reactions include infection, photosensitivity, nausea, hepatotoxicity, and a reversible, dose-related diabetes insipidus syndrome.

* Institute seizure precautions and teach your patient's family how to respond to seizures, which are a risk of hyponatremia.

Severely decreased sodium levels (less than 115 mEq/liter) can cause severe, even life-threatening signs and symptoms. The patient requires intensive nursing care, diuresis, intravenous (I.V.) therapy with hypertonic (3% to 5%) sodium chloride solution, seizure precautions, and chemotherapy.

Mrs. Albanez is placed on fluid restrictions. Pathology tests confirm the SCLC diagnosis with metastasis to the thoracic spine, and she begins chemotherapy. Over several days, her serum sodium level begins to rise and she's scheduled for discharge.

You educate her and her husband about her need to use safety rails in the bathroom at home and to remove loose rugs and other objects on the floor that could interfere with walking. You caution her to report weight gain, reduced urine output, or development of new or recurrent signs and symptoms of SIADH. She's discharged home awake, alert, and oriented.

Spinal cord compression: A threat to sensation and function

Three months after completing her prescribed chemotherapy, Mrs. Albanez goes to the oncology office complaining of back pain that spreads around her waist like a belt. This pain pattern may signal a tumor or collapsed vertebra pressing on a spinal cord nerve. (See Making a bad impression.) Suspecting SCC, the oncologist orders stat magnetic resonance imaging (MRI) of her spine and a stat dose of dexamethasone. If indeed SCC is causing Mrs. Albanez's pain, prompt administration of a corticosteroid will help reduce the pain and spinal cord edema and may prevent disability.

Preventing paralysis

Although many oncology patients have chronic pain, new or worsening back pain always warrants immediate investigation for SCC. A serious, potentially devastating complication of cancer, SCC affects 5% to 7% of oncology patients. It can occur with almost any malignancy, but it's more commonly seen with cancers of the breast, prostate, and lung. Prompt recognition of the signs and symptoms and immediate diagnosis and treatment are key to preventing paralysis.

The thoracic spine is the area most commonly affected by SCC, followed by the lumbosacral region. Compression of the cervical spine is rare. Signs and symptoms include local or radicular pain, which may increase with moving, lying down, coughing, or percussion of the spine at the affected site and with straight leg raises while the patient is lying down.

When SCC is detected and appropriately treated, the patient is more likely to maintain her pretreatment status, such as the ability to walk. Without treatment, SCC will progress and she'll develop weakness and eventual paralysis of the legs, arms, or both, depending on the site of compression. She may have ataxia and lose coordination. Sensory deficits in the extremities and trunk move proximally and include numbness, tingling, and loss of reflexes. If the autonomic nervous system is affected, urine retention and constipation occur, followed by bladder and bowel incontinence.

Pinpointing the problem

Thorough pain and neurologic assessments and diagnostic testing are needed to determine the location of an SCC. Assess your patient's pain characteristics, location, severity, onset, duration, and associated, aggravating, and relieving factors. Find out what pain medications she's taking and whether they're effective.

Neurologic assessments should include the following:

* mental status

* cranial nerves

* motor system

* sensory system

* deep tendon, abdominal, and plantar reflexes. (See Facing Neuro Assessment Fearlessly in the February issue of Nursing2002 for a comprehensive review.)

An MRI of the spine is an accurate, sensitive, and specific diagnostic tool for SCC, whether caused by a malignancy or a nonmalignant condition such as osteoporotic compression fracture. Other useful tests include spinal X-rays and a computed tomography (CT) scan. Myelography should be reserved for someone who can't undergo MRI promptly or whose MRI images are poor.

Once a diagnosis of SCC is made, keep the patient on bed rest until the oncologist determines that her spine is stable and until assistive devices such as a back brace are available. A physical therapist will assess her ability to ambulate and prescribe a regimen of appropriate physical activity.

Mrs. Albanez will continue therapy with the corticosteroid dexamethasone and begin radiation therapy to the affected area. She'll receive opioid medications to manage pain and a laxative to prevent and manage constipation.

Surgery is rarely used to treat SCC, but it may be indicated if a specimen is needed to confirm a cancer diagnosis, if the spine must be stabilized, if the area has received maximal radiation, or if the tumor doesn't respond to radiation therapy. To be a candidate for surgery, the patient must be able to tolerate a major procedure. Newer, less invasive surgical approaches used to treat degenerative problems and osteoporosis are being explored in patients with cancer: Percutaneous vertebroplasty and kyphoplasty both involve injecting bone cement into the damaged vertebral body. Other procedures are under investigation as well.

Assess, protect, and educate

When you care for any patient with cancer, be vigilant for signs and symptoms of SCC. Teach them to your patient and her family and emphasize the need to report them immediately to her health care provider.

The severity of SCC helps dictate the type and level of nursing care the patient requires. An outpatient should have assessments of pain and neurologic, bowel, and bladder function at follow-up visits and in the radiation therapy department. Considerations for a hospitalized patient include frequent neurologic assessments, a turning schedule, meticulous skin care, bowel and bladder regimens, assistance with activities of daily living, pain management, preventing complications due to immobility (such as deep vein thrombosis), physical therapy, and determining code status. Arrange a consult with a social worker or chaplain if appropriate.

Regularly assess your patient's pain level along with sensory and motor function. Depending on her condition, some or all of these measures may also be appropriate:

* If her spine is unstable, keep her on bed rest until she's fitted with a brace to stabilize it.

* Monitor her bowel and bladder function.

* Assess the effectiveness of pain management and recommend modifications if necessary to the prescriber.

* Make sure she has transportation if she's to undergo daily radiation therapy after discharge.

* Arrange for physical therapy, occupational therapy, or a referral to a rehabilitation facility if appropriate.

* Teach your patient signs and symptoms of worsening SCC and tell her to immediately report them to her health care provider.

* Educate her about her pain medication, nonpharmacologic pain management techniques, and safety measures to protect her back and prevent falls.

* Review her dexamethasone schedule and potential adverse reactions to the drug and warn her not to stop taking it abruptly.

* Investigate whether a hospice referral is appropriate when SCC is a late manifestation of cancer.

Mrs. Albanez is diagnosed with SCC and undergoes outpatient radiation therapy Monday through Friday for 2 weeks. Her dexamethasone doses are tapered. A CT scan of the chest, abdomen, and pelvis shows the known vertebral bone metastases that caused the SCC plus several new small lung tumors and liver metastases. She wants to have chemotherapy, so she schedules a visit to the oncology practice for her first cycle of a paclitaxel regimen.

Anaphylactoid reaction: Trouble in a hurry On the day of Mrs. Albanez's chemotherapy appointment, she meets with the medical oncologist and has blood drawn for a complete blood cell count and blood chemistry panel. When she and her husband go to the treatment area, the nurse does the following:

* reviews blood work results

* makes sure the informed consent form is signed

* reviews the oncologist's orders for pretreatment medications and paclitaxel

* checks the patient's height and weight and calculates her body surface area

* reviews her allergy history and asks if she's ever had an unexpected sensitivity reaction to chemotherapy or any other drugs or substances

* checks her drug doses.

After confirming that everything is satisfactory, the nurse calls the pharmacy to have medications prepared for Mrs. Albanez. Because she reported no allergies or sensitivity problems, he inserts an I.V. device and begins patient education.

The nurse tells Mrs. Albanez and her husband about potential problems related to paclitaxel. They include hair loss, bone marrow suppression, and the possibility of an allergic (hypersensitivity) reaction. He stresses the need to speak up immediately if she has trouble breathing, experiences chest or back pain, or feels hot or anxious during the infusion. He makes sure that oxygen and other emergency medications and equipment are ready in case of a drug-related hypersensitivity reaction.

Administering premedications and chemotherapy

To prepare Mrs. Albanez for chemotherapy, the nurse assists her to the infusion chair and premedicates her with I.V. cimetidine, 300 mg; I.V. dexamethasone, 20 mg; and I.V. diphenhydramine HCl, 50 mg. Continuing patient education, he gives the couple written information about paclitaxel and its adverse reactions, including how to manage them if Mrs. Albanez develops problems at home. He explains that the premedications help reduce the risk and severity of hypersensitivity reactions but don't always prevent them.

The nurse hangs a bag of 0.9% sodium chloride solution nearby so it's ready if needed for emergency administration and places a 3-ml syringe containing 0.9% sodium chloride and a few empty syringes near the infusion chair. He takes Mrs. Albanez's vital signs and leaves the blood pressure (BP) cuff on her arm.

He starts the paclitaxel infusion at the prescribed rate. Reassuring Mrs. Albanez as he prepares to sit next to her, he sees her face redden while she clutches her chest and says she can't breathe. He immediately stops the infusion and calls for help. Disconnecting the I.V. tubing from the venous access device, he aspirates residual drug from the cannula, flushes it with the 0.9% sodium chloride solution in the syringe, connects the prehung 0.9% sodium chloride I.V. solution to the cannula, and starts the infusion to keep the vein open.

Following facility protocol, another nurse checks Mrs. Albanez's vital signs and applies a pulse oximetry sensor to her finger. Her BP is 90/60, her heart rate is 140, her respiratory rate is 30, and her SpO2 level is 81%.

The infusion nurse administers supplemental oxygen; subcutaneous epinephrine, 0.5 ml of 1:1,000 solution; an additional 50 mg of diphenhydramine HCl by I.V. push; and 125 mg of methylprednisolone sodium succinate by I.V. push. Within 5 minutes, Mrs. Albanez begins to stabilize. The nurse offers her and her husband emotional support and encourages them to share their feelings with him.

Exploring what happened

Mrs. Albanez experienced a hypersensitivity reaction. She's never before been exposed to paclitaxel, so the reaction is termed anaphylactoid. This indicates an extreme response to spontaneous release of inflammatory mediators that cause clinical manifestations like those of anaphylaxis, including bronchospasm, hypotension, tachycardia, and chest pain. Unlike true anaphylaxis, which involves an immune adverse reaction during a subsequent exposure to an antigen, an anaphylactoid reaction occurs on the initial exposure. (See What's behind an anaphylactoid reaction to learn more about the differences.) Either paclitaxel or the vehicle Cremophor EL in the solution is probably responsible for the reaction.

To treat an anaphylactoid reaction, you must withdraw the offending agent immediately; maintain the patient's airway, breathing, and circulation; and administer I.V. fluids and medications to manage her signs and symptoms. She may need to be taken to the ED if she doesn't respond to emergency measures, if her condition deteriorates, if she has other conditions that require ongoing monitoring, or if she has a risk of relapse.

A nurse who administers antineoplastic drugs must be knowledgeable about the drugs that can trigger anaphylactic or anaphylactoid reactions, as well as the premedication regimens, signs and symptoms, and emergency interventions. Patient education is critical so the patient will know how to recognize and report symptoms that may develop before you notice flushing, rash, or other visible signs.

As Mrs. Albanez's hemodynamic status returns to normal, she and her husband begin to relax and ask if therapy can continue. The oncologist explains that she can undergo chemotherapy with a different antineoplastic agent, such as topotecan, or continue treatment with paclitaxel after receiving oral dexamethasone every 6 hours overnight followed by I.V. premedications and a paclitaxel desensitization regimen. Other options are to participate in a clinical trial of a different drug or enter hospice care. She wants to go home and discuss her options with her family before deciding how to proceed.

Protecting the patient

Following Mrs. Albanez shows how cancer and cancer therapy can precipitate life-threatening emergencies at various stages of the disease and treatment plan. Now that you understand how to recognize SIADH, SCC, and anaphylactoid reaction, you're better prepared to protect your patient against these serious problems and help her get the maximum benefit from her anticancer regimen.

SIADH: Fluid regulation gone awry

The pituitary releases antidiuretic hormone (ADH) to regulate water output and reabsorption by the kidneys. When plasma osmolality goes above the normal set point, osmoreceptors in the hypothalamus stimulate ADH release to decrease urine output and restore plasma osmolality to its set point.

In certain malignancies, including small cell lung cancer, the tumor cells produce ectopic ADH. The excessive amount leads to excessive water retention, causing concentrated urine, dilute plasma, and dilutional hyponatremia. Excess water enters the cells and causes signs and symptoms. Swelling of the brain cells is especially important because it affects the central nervous system.

Making a bad impression

Spinal cord compression occurs when a growing tumor presses on the spinal cord or metastases replace or erode the vertebrae, causing them to collapse and press on the spinal cord. The result is impaired blood supply to the affected area and development of hypoxia, edema, venous stasis, and spinal cord injury.

The thoracic region is most commonly involved. Initially, pressure on a nerve root causes chest or back pain, pain girdling the affected area, hypersensitivity to touch near the area, or pain in the opposite leg.

If the pressure isn't relieved, further spinal cord injury will lead to loss of sensory and motor function and loss of bowel, bladder, or sexual function.

What's behind an anaphylactoid reaction

Anaphylactic and anaphylactoid reactions cause the same clinical manifestations, but their pathologic processes differ.

An anaphylactic reaction occurs on subsequent exposure to an antigen after previous exposure causes gamma E immunoglobulin antibodies to form. The reexposure triggers an excessive immune response with mild to severe-and possibly life-threatening-signs and symptoms.

An anaphylactoid reaction is an immediate systemic response to an antigen without prior exposure. The antigen binds to the surfaces of mast cells and basophils to cause release of inflammatory mediators and histamine that trigger the response. Because previously formed antibodies aren't involved, the reaction isn't true anaphylaxis.

Both anaphylactic and anaphylactoid reactions can cause chest pain, bronchospasm, edema, hypotension, tachycardia, arrhythmias, flushing, itching, nausea, vomiting, and other serious and potentially fatal reactions.