Sickle cell disease, an disease of red blood cells

Introduction

This paper presents a detailed overview of sickle cell disease, an inherited disease of the red blood cells. The paper begins with a brief discussion of the aetiology, prevalence of sickle cell disease. Next the paper investigates the pathophysiological aspects of the disease and the physical manifestation of symptoms the patient presented with. The paper then discusses how sickle cell disease affects suffer. Finally the paper presents and evaluates treatment and management of care. The conclusion will provide a summary of the points discussed.

Sickle cell disease (SCD) encompasses a group of haemo­globinopathies. There is currently no cure for adults with this hereditary disease, which mainly affects people of Afro-Caribbean origin and, to a lesser extent, Mediterra­nean, Middle Eastern and Asian groups. There are large numbers of people around the world who suffer from acute or chronic pain, or indeed both, as a result of sickle cell disease. Sickle Cell Society (2008) estimates that sickle cell disease affects approximately 10 000-12 500 people in the UK.

Sickle cell disease comprises of a group of inherited blood disorders that alter a person’s haemoglobin, causing chronic haemolytic anaemia and producing acute and chronic pain as a result of reoccurring episodes of vascular occlusion (Lal. and Vichinsky, 2005). Adult haemoglobin consists of two alpha globin and two beta globin chains wrapped around a haem (iron containing) molecule. Haemoglobin – is the main substance of the red blood cell. It helps red blood cells carry oxygen from the air in the lungs to all parts of the body. Normal red blood cells contain haemoglobin A. Haemoglobin S and haemoglobin C are abnormal types of haemoglobin. Normal red blood cells are soft and round and can squeeze through tiny blood tubes (vessels). Normally, red blood cells live for about 120 days before new ones replace them.

People with sickle cell conditions make a different form of haemoglobin A called haemoglobin S (S stands for sickle). This is caused by mutation in the beta chain which means the haemoglobin has a lower affinity for oxygen that causes sickle cell anaemia is the most common (Serjeant & Serjeant, 2001). The mutation causing sickle cell anaemia is a single nucleotide substitution (A to T) in the codon for amino acid 6. The change converts a glutamic acid codon (GAG) to a valine codon (GTG). The form of haemoglobin in persons with sickle cell anaemia is referred to as HbS (Bain, 2002). The nomenclature for normal adult haemoglobin protein is Hb. Red blood cells containing mostly haemoglobin S do not live as long as normal red blood cells (normally about 16 days) (De, 2005). They also become stiff, distorted in shape and have difficulty passing through the body’s small blood vessels. De (2008) explains when sickle-shaped cells block small blood vessels, less blood can reach that part of the body. Tissue that does not receive a normal blood flow eventually becomes damaged (Serjeant & Serjeant, 2001). This is what causes the complications of sickle cell disease. People who inherit the mutation from both parents or the mutation from one and thalassaemia (lack of a beta chain) from the other will suffer sickling. Those who inherit the mutation from only one parent will be sickle cell disease carriers and rarely display symptoms (Information Centre for Sickle Cell and Thalassaemic Disorders, 2008).

Patient X presented in accident and emergency (A&E) in sickle cell pain crisis. Vaso-occlusive pain is caused by the tendency of sickle haemoglobin molecules to crystallise, distorting the red cells into crescent shapes on deoxy­genation, occluding small blood vessels. Disrup­tion of normal circulation leads to acute tissue ischaemia and secondary inflammation and, when prolonged, infarction of bone, joints and vital organs (Elander et al, 2004). According to Information Centre for Sickle Cell and Thalassaemic Disorders (2008) vaso-occlusive pain episodes experienced by patients with sickle cell disease vary tremendously in frequency and severity. Some patients rarely have painful crises, while others spend the greater part of a given year in the hospital receiving analgesics (Anglin, 2007). The cooperative study of the natural history of sickle cell disease showed that about 5% of patients accounted for one-third of hospital days devoted to pain control (cited in Johnson, 2004). To complicate matters further, the pattern of pain varies over time, so that a patient who has a particularly severe year may later have a prolonged period characterized by only minor pain.

According to Sickle Cell Society (2008) the frequency and severity of vaso-occlusive pain episodes often change as a person moves from childhood to being an adult. The “breakpoint” often occurs during the late teens or early 20’s. Changes in hormonal status that occur during these years could contribute to the changes in severity of sickle cell disease (Information Center for Sickle Cell and Thalassaemic Disorders, 2008). However, no causal relationship has been established, so the association remains only temporal. The mode of onset of sickle cell pain crises likewise varies. Roberts & de Montalembert (2007) states patients can develop agonisingly severe pain in as little as 15 minutes. In other instances, the pain gradually escalates over hours or even days. Acute tissue ischaemia is associated with extreme pain, which may last from hours to weeks. The average duration is 5-7 days (Johnson, 2004) and the episodes are usually self-limiting. Streetly (2005) stresses prolonged infarction can lead to a multitude of compli­cations, such as organ damage, degeneration of the spine and joints, and ischaemic leg ulcers. These compli­cations are associated with chronic pain and disability. The sites affected in acute painful crises vary for each patient. Pain occurs commonly in the extremities, thorax, abdomen, and back (Oni, 2009). Pain tends to recur at the same site for a particular person. For each person, the quality of the crisis pain is usually similar from one crisis to another.

Patient X had been managing the pain at home with paracetamol, heat rubs and 50mg of diclofenac a non-steroidal anti-inflammatory drug (NSAID). Sickle Cell Society (2008) states most patients manage episodes of pain at home. Oral analgesics, combined with rest and fluids often allows a person to “ride out” the pain episode. Some patient’s report that warm baths or warm compresses applied to aching joints ameliorates the severity of the pain (Roberts & de Montalembert, 2007). Patient X’s pain became progressive worse so presented in A&E for stronger opioid medication. According to the Trust policy a comprehensive, multidisciplinary team strategy is essential, particularly for managing patients with fre­quent acute or chronic pain. Therefore, on admission patient X was assessed by the doctor and a pain assessment was undertaken by the nurse.

According to Wright & Adeosun (2009) patients presenting in accident and emergency departments with a painful episode should be immediately triaged and administered analgesia within 15 minutes of arrival and a prompt, accurate pain assessment is the cornerstone of effective pain management. It should include pain site, duration, score, character, exacerbating and relieving factors, associated symptoms, previous analgesia and physical examination. Ideally, the assessment tool would be locally recognised and used and therefore be familiar to patients. Moreover assessment should be prompt to expedite pain relief and allow life-threatening syndromes, such as acute sickle chest syndrome, to be treated urgently (Johnson, 2004).

During the assessment patients will benefit from reassurance that they are believed when they report pain and that med­ication will be delivered swiftly. De (2005) however reports incidences where healthcare professionals have not believed the patient report of pain which resulted in the patient displaying pseudo-addictive behaviour in an attempt to manage their pain and receive appropriate analgesia. This behaviour is an iatrogenic syndrome resulting from poorly treated pain (Serjeant & Serjeant, 2001). According to Stuart & Nagel (2004) without adequate knowledge of prompt assessment and management and how this can manifest, pseudo-addictive behaviour, such as groaning or other physical behaviour where the patient is trying to demonstrate that they are in pain, can be misconstrued as behaviour associated with substance addiction. Such behaviour could be, for example, aggression, conflict and arguments about analgesia. Wright & Adeosun (2009) contends it is important to remember that this behaviour, although similar to behaviour found in substance dependence, is actually a result of poor pain management and is an indicator that this person needs their pain management approach reviewed urgently.

In line with the Trust policy patient X was triaged within 15 minutes and during the evaluation, the doctor asked patient X whether the pain feels like “typical” sickle cell pain. Most patients can distinguish back pain due to pyelonephritis or abdominal pain due to cholecystitis, for instance, from their typical sickle cell pain (Anglin, 2007). De (2005) contends if the quality of the pain is not typical of their sickle cell disease, other causes should be investigated before ascribing it to vaso-occlusion. As this was typical of patient X’s sickle cell disease the doctor prescribed morphine 10mg titrated against the level of pain. Opioid-agonist drugs like Morphine are the mainstay of treatment for acute sickle cell disease pain and can be given orally. The dose must be titrated appropriately to reflect the drug’s thera­peutic duration of action and the intensity of the pain. Johnson (2004) contends patients whose pain is severe enough to warrant hospitalisation usually require opioids.

Morphine an agonists, opioid and it works by attaching to opioid receptors. There are four types of receptor: mu (μ); delta (δ); kappa (κ); and opioidreceptor- like (ORL). The μ receptors are thought to be responsible for most of the analgesic effects of the opioids and for some of the main unwanted morphine derivatives which include respiratory depression, hypotension, sedation, nausea, pruritis, constipation and dependence (Hall, 2009). Drugs may then need to be given to relieve and prevent analgesic side-effects (Hall, 2009). The morphine was administered intramuscularly (IM) however Johnson (2004) argues that pain relief occurs more slowly with intramuscular injections, and the injections themselves can produce substantial discomfort. Consequently, intravenous administration of analgesics is usually preferable.

Maxolon 10mg was prescribed intravenously (IV) because of the undesirable side effects commonly associated with opioids. Opioids may induce nausea and vomiting by stimulating the chemoreceptor trigger zone, reducing gastrointestinal motility or increasing vestibular sensitivity (Hall, 2009). Evidence shows that nausea and vomiting can negatively affect the quality of life of patients in term of functional outcomes, patient-perceived care by hospital staff and patient satisfaction with regard to overall hospital stay (Information Center for Sickle Cell and Thalassaemic Disorders, 2008). Identifying the incidence of nausea and vomiting and characterizing the prescribing of antiemetics are necessary in an effort to improve tolerability of opioids.

Maxolon injection contains the active ingredient metoclopramide hydrochloride, which is a type of medicine called a dopamine antagonist (British National Formulary, 2010). Metoclopramide works primarily by blocking dopamine receptors found in an area of the brain known as the chemoreceptor trigger zone (CTZ). The CTZ is activated by nerve messages from the stomach when an irritant is present (Hall, 2009). Once activated, it sends messages to the vomiting centre in the brain which in turn sends messages to the gut, causing the vomiting reflex. Blocking the dopamine receptors in the CTZ prevents nausea messages from being sent to the vomiting centre. This reduces the sensation of sickness and prevents vomiting (Finlay, 2004). Once both drugs had been administered the role of the nurse was to monitor effectiveness and to reassess the pain score. Patient X was encouraged to report any further pain accordingly. According to Johnson (2004) as pain control improves, the analgesia should be maintained to prevent the patient from slipping back into a painful cycle.

Patient X was then nursed in the observation unit and after 2 hours reported increasing. After being reviewed by the pain team a patient controlled analgesia (PCA) was offered. The popularity of PCA has generally risen since a report published by the Royal College of Surgeons of England and the College of Anaesthetists (1990), and PCA is now regarded as a routine, safe modality associated with high levels of satisfaction among postoperative patients (Ballantyne et al, 1993). While much has been written about PCA in connection with postoperative pain, comparatively little has been reported in connection with sickle cell disease pain. Of the few studies focusing on PCA use by sickle cell disease patients, Gonzalez et al (1991) has attempted to measure patients’ acceptance of PCA, and then only as the secondary goal of a clinical trial.

In a much early pilot study of three adolescents with sickle cell disease Schechter et al (19880 suggested that drug usage may dramatically reduce as pain subsides, but the intended trial was never conducted because doctors feared it might fuel patients’ propensity for addiction. The Society Cell Society (2008) however report that some sickle cell patients actually disliked receiving morphine because of its association with drug abuse and addiction and Johnson (2003) findings indicate that some sickle cell disease patients prefer to receive PCA to promote fast and predictable pain relief and give themselves a degree of control over their pain. Moreover, continuous subcutaneous infusions have been used to counteract any delays between intramuscular and intravascular injections (Hall, 2009). This also takes away the reliance on the next dose having to be delivered by health professionals and thus promotes patient autonomy.

The role of the nurse was to teach patient X and his family about the medication: description, action, effects, and possible side effects. Johnson (2003) stresses the importance of reinforcing that analgesics make pain manageable and it may not take the pain away completely. The subcutaneous route was used for the PCA. Diamorphine was prescribed because it has the advantage of being more water and lipid-soluble, making it more rapid acting, easier to inject in smaller volumes such as 5-10mg per ml subcutaneously (Hall, 2009) and avoids absorption problems (Rees et al, 2002). Typically, bolus doses of diamorphine need to be higher than in postoperative PCA regimens, for example 5-30mg, and lockout times longer, which can be 20-60 minutes.

To increase safe practice around the use of PCAs, a double check of pump settings and medication orders is required when a new syringe is loaded into the PCA system and with subsequent dosage changes. This double check was performed by the nurses and documented on the PCA chart on an hourly basis. Hall (2009) points out that patient can become drowsy as their pain is controlled. Often, this reflects the fatigue that comes with one or more sleepless nights with pain crisis at home. Johnson (2004) reinforced by Oni (2009) argue that the analgesics should not be discontinued automatically for somnolence as long as the patient is easily aroused. A common misconception is that if a patient with sickle cell disease is sleeping, the analgesics are controlling the pain. Rees (2003) contends sickle cell disease patients often sleep despite severe pain.

Therefore, when a PCA has been commenced the nurse should evaluate the patient for respiratory status (rate and depth), sedation level, side effects, and pain severity 2 hours x 12 hours, then 4 hours thereafter (De, 2005). A pulse oximetry was used to monitor saturations levels and patient X was commenced on 2 litres of oxygen as it is in their deoxygenated state that red blood cells containing Hb S take on their abnormal, rigid half-moon-like state (Information Center for Sickle Cell and Thalassaemic Disorders (2008). Research suggests that sickled cells can actually regain their normal disc shape when exposed to a higher oxygen concentration (Zipursky et al, 1992 cited by Sickle Cell Society, 2008).

When oxygen therapy is being administered De (2008) advocates an upright position as this position optimises and maintains ventilation and perfusion. Patient X needed assistance due to the pain to sit upright and a mouth care tray was provided due to the side effect of oxygen therapy causing dryness of the nasal and oral mucosa (Sheppard and Davis, 2000). A jug of water was also made available at the bedside and the call buzzer was left in easy reach. Effective management of an episode of painful sickle crisis according to Lal and Vichinsky (2005) requires intravenous fluids as this will help to decrease blood viscosity, improve blood flow and reduce risk of renal compromise.

Providing adequate hydration is a component of almost every treatment protocol for vasoocclusive crises (De, 2005). Dehydration is one of the principal precipitating factors for pain crises. However, overcorrection of fluid balance can have a negative effect, including possibly increasing the risk of acute chest syndrome. This syndrome, characterized by cough, chest pain, dyspnoea, fever, and radiographic changes, is the most common cause of death for patients with sickle cell disease (Information Center for Sickle Cell and Thalassaemic Disorders, 2008). Stuart and Nagel (2004) suggest hydration should be provided to correct deficits, replace any ongoing losses, and maintain normal body fluid volume (euvolemia). In addition, to this the patient’s pain may improve with oral hydration. Patient X was prescribed 1 litre of intravenous (IV) normal saline over 8 hours and oral hydration was encouraged by the nursing staff. This was monitored on the fluid balance chart.

Patient X’s vital signs temperature, pulse, blood pressure were continuously monitored to detect any changes. Patients with sickle cell disease are susceptible to overwhelming infection (Wright & Adeosun, 2009; Stuart & Nagel, 2004). The most significant factor is splenic autoinfarction during childhood (Sickle Cell Society, 2008). Functional asplenia leaves patients vulnerable to infections with encapsulated organisms such as Streptococcus pneumoniae and Hemophilus influenzae. Further, some studies suggest that neutrophils do not function properly in patients with sickle cell disease (Information Center for Sickle Cell and Thalassaemic Disorders, 2008). How the mutation in sickle cell disease might lead to a defect in neutrophil function is unclear.

Patients with SCD and unexplained fever should be cultured thoroughly. If the clinical condition suggests septicaemia, the best action is to start broad spectrum antibiotics after complete culturing. Signs of systemic infection include fever, shaking chills, lethargy, malaise, and hypotension (Oni, 2009). Patient remained apyrexial and 2 days after admission the quantity of analgesia was slowly reduced as patient X’s symptoms improve. While the tapering of intravenous analgesics can require only two or three days, control of a full blown crisis often requires 10 to 14 days. Less commonly, bouts of sickle vaso-occlusive pain require several weeks to control.

In conclusion this paper has presented a detailed overview of the management of pain in sickle cell disease, an inherited disease of the red blood cells. Sickle cell disorder can have a profound effect on a person’s life. Acute painful episodes among patients with sickle cell disease may occur in any body part or several sites simultaneously. A thorough pain assessment will indicate the type of pain management approaches that are most likely to be effective. Patients should always be encouraged to engage in activities that will help them manage their own pain and boost their confidence rather than make them dependent on health care professionals. This case profile has highlighted the importance of optimal care for a patient with sickle cell disease which should be a comprehensive, multidisciplinary team approach with prompt, accurate pain assessment as this is the cornerstone of effective pain management.