Recurrent and unpredictable episodes of vaso-occlusion are the hallmark of .. Intravenous immunoglobulins reverse acute vaso-occlusive crises in sickle cell. The cause of vaso-occlusive crisis (VOC) is believed to be ischemic and cold can precipitate crises. . what has worked in previous crises. One study from Oman reported periorbital swelling during vaso-occlusive crises in five patients The patients ranged in age from 6 to 15 years old. Four of.

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This is a corrected version of the article that appeared in print. See related patient information handout on practical tips for preventing a sickle cell crisiswritten by the authors of this article. Acute episodes of severe pain crisee are the primary reason that these patients seek medical care in hospital baso departments.

Frequently, however, the pain is incompletely treated. Despite advances in pain management, physicians are often reluctant to give patients adequate dosages of narcotic analgesics because of concerns about addiction, tolerance and side effects. It is important to recognize a pain crisis early, correct the inciting causes, control pain, maintain euvolemia and, when necessary, administer adequate hemoglobin to decrease the hemoglobin S level. The family physician and the hematologist must work together to treat acute pain episodes promptly and effectively, manage the long-term sequelae xrise chronic pain and prevent future vaso-occlusive crises.

The vaso-occlusive crisis, or sickle cell crisis, is initiated and sustained occluzive interactions among sickle cells, endothelial cells and plasma constituents.

Acute pain in patients with sickle cell disease is caused by ischemic tissue injury resulting from the occlusion of microvascular beds by sickled erythrocytes during an acute crisis. Chronic pain occurs because of the destruction of bones, joints and visceral organs as a result of recurrent crises.

The effect of unpredictable recurrences of acute crises on chronic pain creates a unique pain syndrome. Acute bone pain from microvascular occlusion is a common reason for emergency department visits and hospitalizations in patients with sickle cell disease.

The severe pain is believed to be caused by increased intra-medullary pressure, especially within the juxta-articular areas of long bones, secondary to an acute inflammatory response to vascular necrosis of the bone marrow by sickled eythrocytes.

The approach to pain control must include measures to treat acute pain crises, prevent future vaso-occlusive crises and manage the long-term sequelae of chronic pain that can result from multiple recurrent bony infarctions.

Epidemiologic data indicate that 5. A severe crisis may cause pain that persists for weeks to months. When a vaso-occlusive crisis lasts longer than seven days, it is important to search for other causes of bone pain, such as osteomyelitis, avascular necrosis and compression deformities.

When a recurrent bone crisis lasts for weeks, an exchange transfusion may be required to abort the cycle. The frequency, severity, location and duration of pain crises can vary considerably, even within a specific disease subtype.

The psychologic, behavioral and cultural profile of individual patients also influences their perception of pain and their ability to cope with the pain. A vaso-occlusive crisis most commonly involves the back, legs, knees, arms, chest and abdomen.

Bone pain tends to be bilateral and symmetric. Recurrent crises oocclusive an individual patient usually have the same distribution. An acute abdominal pain crisis often resembles an intra-abdominal process such as cholecystitis or appendicitis.

Diagnoses that may require surgery and suggest a process other than vaso-occlusive crisis include pain in the absence of a precipitating event, pain that differs from the pain experienced in previous vaso-occlusive crises, and lack of pain relief within 48 hours despite hydration and oxygen therapy. The work-up of the patient with a vaso-occlusive crisis should include a complete history, a physical examination, selected laboratory tests and a search for reversible conditions known to precipitate pain crises.


The physician should look for clinical evidence of dehydration and infection. The extent of bone and soft tissue involvement should also be assessed. Routine laboratory testing is unnecessary in patients with uncomplicated vaso-occlusive crises. If a patient has symptoms that are severe enough to warrant hospitalization, laboratory tests should include a complete blood count, reticulocyte count and urinalysis.

If fever is present, a chest radiograph should be obtained, and urine, sputum and blood should be cultured for a possible source of infection.

Fever is common in patients with an uncomplicated vaso-occlusive crisis and does not necessarily indicate the presence of an underlying infection. Predicting when a vaso-occlusive crisis may occur xrise be difficult. A number of factors, however, including dehydration, infection and cold weather, are known to precipitate acute crises Table 1.

Information from references 24 and 5. Patients need to be aware of the factors that can precipitate vaso-occlusive crises.

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These patients are particularly susceptible to dehydration because of a reduced ability to conserve water secondary to a defect in renal concentrating ability. They should be counseled to wear warm clothes in cold weather, drink adequate amounts of fluids in hot weather and avoid exercising to the point of fatigue and dehydration Table 2. Consuming adequate amounts of fluids to prevent dehydration especially during febrile periods and hot weather. Avoiding mountain climbing or air flights in an unpressurized vasl noncommercial flights above 10, feet.

Avoiding exposure to extreme cold, exercising to exhaustion or using drugs that can lead to acidosis e. Genetic screening and vocational counseling about working e. Avoiding hypoxemia in the perioperative period when general anesthesia is used or when a procedure involves hypertonic radiographic dyes.

Acute sickle cell crises are managed primarily with drug therapy.

Psychologic supportive care is also important. The standard treatment approach includes opioid analgesics, adequate hydration, rest, and cognitive and behavioral therapies.

Optimal management requires a multidisciplinary team that includes a family physician, a hematologist, nurses, a psychiatrist, a physical therapist, a pain specialist and social workers.

These team members work together to provide empathetic, consistent, longitudinal care in a trustworthy environment. Pain scales can be useful for quantifying the intensity of pain. These tools include the visual analog scale, the verbal categorical scale and the pain relief scale. Several of these measures are shown in Figure 1. Techniques for determining the severity of pain and its location. Top The visual analog scale quantifies the intensity of pain. This scale is useful for titrating the dosages of narcotic analgesics and planning for hospital discharge.

Vaso-occlusion in sickle cell disease: pathophysiology and novel targeted therapies

Bottom The drawings are used to evaluate the spatial distribution of pain. Guidelines for standard of care of acute painful episodes in patients with sickle cell disease.

Commonwealth of Pennsylvania Department of Health, The visual analog scale has been found to be a clinically crisd objective parameter for titrating narcotic analgesics and planning hospital discharge. The verbal pain scale can be used if a patient is unable to provide a written response to the visual analog scale. The patient is asked to report pain intensity verbally on a scale of zero no pain to 10 worst pain possible.

The degree of pain relief is based on a scale of zero to percent. The patient can also be asked to mark the area of pain on a scaled body drawing Figure 1. Pain from a vaso-occlusive crisis is often undertreated because of concerns about narcotic addiction and tolerance, perceived drug-seeking behavior, excessive sedation, respiratory depression and lack of specific findings criise the physical examination.

Physicians often fail to prescribe narcotics appropriately and tend to overestimate opioid dependence in patients with pain crises.

Oxygénothérapie hyperbare dans la crise vaso-occlusive drépanocytaire – EM|consulte

Yet the incidence of opioid analgesic addiction in patients with sickle cell disease has been reported to be no higher than 3 percent. Many drug regimens have been effective in the treatment of acute pain in sickle cell disease. Nonsteroidal anti-inflammatory drugs can be used unless they are specifically contraindicated because of peptic ulcer disease, renal disease or hepatic dysfunction.


Information from references 3 and 4.

Vaso-occlusive crisis

Narcotic analgesics can be used in patients with moderate to severe pain. The dosage of the selected narcotic should be titrated to achieve effective pain control. Often used in combination with acetaminophen, which limits safe dosage to 12 tablets per day about 4 g of acetaminophen.

Information from references 34 and If a patient has poor venous access and is unable criise take enteral narcotics because of vomiting, the subcutaneous route can be employed, using morphine or its equivalent.

It is important to remember that subcutaneous administration may result in prolonged absorption if a patient is dehydrated. Adjuvant nonopioid agents such as antihistamines and antiemetics can be helpful for preventing or relieving opioid-related side effects.

Nonpharmacologic techniques can also be tried. These measures include physical therapy, rest, heat application, transcutaneous electrical nerve stimulation TENSoccludive and diversional techniques. In the past, moderate to severe pain in sickle cell disease was usually treated with meperidine Demerol administered parenterally or, more commonly, intramuscularly.

Compared with morphine, however, meperidine has a number of properties that make it a poor opioid analgesic for repeated use faso most patients with sickle cell disease. Meperidine is a weak opioid analgesic with a short half-life two to three hours. Thus, frequent dosing is required to maintain a sustained analgesic effect.

In addition, normeperidine, a metabolite of meperidine, has been associated with seizures, particularly in patients with impaired renal function who are being given high doses at frequent intervals.

For these reasons, parenterally administered morphine should be considered the treatment of choice for moderate to severe pain in vaso-occlusive crises. Morphine’s side effects include pruritus, nausea, vomiting and rash. In addition, dosage adjustments are necessary in patients with liver dysfunction. Some patients prefer meperidine for the treatment of pain crises and may be reluctant to change to morphine.

Analgesia should be discussed when patients are not in pain. Regardless of the type of opioid analgesic used, respiratory rate and oxygen saturation must be closely monitored because oclusive the potential for respiratory depression.

If the respiratory rate is less than 10 per minute or excessive sedation occurs, the opiate should be discontinued, the dosage should be reduced or the dosing frequency should be lengthened.

With parenteral administration, narcotic analgesics can be given using crixe fixed schedule with rescue doses administered for breakthrough paincontinuous infusion or patient-controlled administration. Patient-controlled analgesia offers several unique advantages in the treatment of severe pain occurring in a vaso-occlusive crisis. Patient-controlled analgesia prevents fluctuation in blood drug levels and may reduce the time between the perception of pain and the administration of the analgesic.

This approach reduces overmedication and excessive sedation. It also provides patient autonomy and decreases the nursing time required for analgesic administration. Oxygen therapy is often used routinely in the management of vaso-occlusive crises, despite lack of evidence supporting the effectiveness of these measures in all patients. Hence, oxygen should be administered only if hypoxemia is present. Pulse oximetry cruse not be a reliable method of determining the PaO 2 in patients with sickle cell disease.

All low pulse-oximetry saturation values should be compared with values obtained at steady state, if available, or should be confirmed by measuring the PaO 2 directly with an arterial blood gas determination. Most patients with sickle cell anemia have hemoglobin values of 6 to 10 g per dL 60 to g per L.