Darcy Brodecki

Hypoxaemia in sickle cell disease: biomarker modulation and relevance to pathophysiology

BACKGROUND Nocturnal oxyhaemoglobin desaturation might have a role in CNS complications related to sickle cell disease, and rates of painful crises. We attempted to examine the biological relations, and describe the haematological risk factors for oxyhaemoglobin desaturation. METHODS The study population included children with sickle cell disease and controls. Cellular activation was assessed by measurement of soluble vascular cell adhesion molecule 1, P-selectin, L-selectin, and leukotriene B4. Erythrocyte-endothelial adhesion and routine haematological variables were assessed. Oxygen saturation (SaO2) was measured by pulse oximetry while children were awake and asleep. Children with a mean sleeping SaO2 of < or =93% were identified as hypoxaemic. Children were divided into four groups: controls (ten children), HbSC (nine, all normoxic), HbSS normoxic (13), and HbSS hypoxaemic (15). FINDINGS Among haematological variables, sleeping SaO2 correlated only with packed-cell volume (r=0.7; p<0.0001). Inverse relations were noted between sleeping SaO2 and adhesion (-0.45; p<0.01), and markers of white-cell (-0.51; p<0.01), platelet (-0.61; p<0.001), and endothelial activation (-0.46; p<0.01). In the HbSS group who had sleeping hypoxaemia, waking SaO2 measurements showed continuing hypoxaemia, with similar correlation between SaO2 and cell activation markers. INTERPRETATION Our adhesion-related findings suggest a potential mechanism for the increased occurrence of clinical vaso-occlusive crises in individuals with sickle cell disease who have oxyhaemoglobin desaturation. Release of cellular mediators in hypoxaemia, and the relation between anaemia and oxyhaemoglobin desaturation, suggest that risk factors for stroke, including anaemia, might have a role in CNS-vasculopathy through hypoxia-mediated pathways. Further more, hypoxaemia in the older child also occurs during the day; such mild untreated hypoxia could lead to an increased risk of vaso-occlusive episodes.

Home management of pain in sickle cell disease: a daily diary study in children and adolescents.

Purpose To determine the incidence of pain and the types of home pain management techniques used by children and adolescents with sickle cell disease (SCD) and their caregivers. Patients and Methods Thirty-seven children and adolescents (ages 6–21 years) with SCD used a self-report pain diary twice daily to report their pain experience and its management for 6 months to 3 years. A total of 18,377 diary days representing 514 distinct pain episodes were analyzed. Results Pain related to SCD was reported on 2592 days and 2326 nights, with analgesic medication taken on 88% of days and 76% of nights. A single oral analgesic was used on 58% of these days. On the remaining days, multiple analgesics were used in a variety of combinations. More frequent analgesic dosing was reported on days with more intense pain. Pain relief was substantially better for analgesic combinations than for single analgesics, particularly for moderate to severe pain. Conclusions Pain went untreated on a modest number of days, and many patients relied on relatively ineffective single analgesics. Other patients and families appropriately used potent analgesic combinations in a time-contingent and intensity-dependent pattern. This study suggests that recurrent acute pain from SCD can be successfully managed at home with appropriate training and supervision, and suggests several areas for intervention to improve patient outcomes.

Physical and cognitive‐behavioral activities used in the home management of sickle pain: A daily diary study in children and adolescents

There is little information documenting the use of cognitive‐behavioral and physical pain relieving activities by children and adolescents for management of pain related to sickle cell disease (SCD).

Pain Characteristics and Age-Related Pain Trajectories in Infants and Young Children with Sickle Cell Disease

The epidemiology of painful episodes in infants and younger children with SCD has not been well studied, particularly for pain managed at home.