Predicting the risk of adverse events in children with febrile neutropenia: A validation of previously identified clinical decision rules

Green, Lindy-Lee (2016-12)

Thesis (MMed)--Stellenbosch University, 2016.

Thesis

ENGLISH SUMMARY: Purpose The purpose of the study was to validate an existing clinical risk assessment tool (Ammann tool) to predict adverse events (AEs) in children with cancer and febrile neutropenia (FN). Patients and methods Patients less than 16 years of age with confirmed malignancies receiving chemotherapy and who presented to the Tygerberg hospital paediatric oncology unit, with fever (axillary temperature > 38 C twice in 24 hours or > 38.5 C once) and neutropenia (neutrophil count < 500 cells/mm3) were enrolled. A risk prediction score1 was calculated for each patient according to the Ammann rule, and AEs were documented until antibiotics had been stopped and neutropenia resolved. The risk prediction score included haemoglobin > 9 g/dL, white cell count < 0.3 g/L, platelet count < 50 g/L and chemotherapy more intensive than acute lymphoblastic leukaemia maintenance therapy. AEs were defined as severe medical complications, microbiologically defined infection and radiologically confirmed pneumonia. Results There were 100 FN episodes in 52 patients, of whom 54% had haematological malignancies, 44% solid tumours and 2% central nervous system tumours (relapsed malignancies 16%). The male:female ratio was 1.8:1 with a median age of 56 months (mean age of 71 months; range 8 to 175 months). AEs occurred in 18/57 (45%) patients with a low risk (score < 9) and 22/43 (55%) with a high risk (score ≥ 9), yielding a sensitivity of 56.8%, specificity of 65%, positive predictive value of 50% and negative predictive value of 71%. Total WCC (p = < 0.01) and absolute monocyte count (p = 0.05) were significantly associated with an AE. Antibiotic-resistant microorganisms were found in 18% of microbiologically confirmed FN. There were marked differences in the patient cohorts between high-income countries versus a low- to middle-income country with a lower median age and more resistant organisms. Conclusion Although this study did not succeed in validating the risk assessment tool (Ammann tool), it demonstrated the important association between total WCC, absolute monocyte count and an AE during FN.

AFRIKAANSE OPSOMMING: Doel Die doel van die studie was om ’n bestaande instrument vir kliniese risikobepaling (die Ammann-instrument) vir die voorspelling van ongewenste gebeure by kinders met kanker en koorsige neutropenie te staaf. Pasiënte en metodes Pasiënte jonger as 16 jaar wat chemoterapie vir bevestigde kwaadaardighede ontvang en wat koors (okseltemperatuur >38 C twee keer binne 24 uur, of >38,5 C eenmalig) sowel as neutropenie het (neutrofieltelling <500 selle/mm3), is in die studie opgeneem. ’n Risikovoorspellingstelling1 is volgens die Ammann-reël vir elke pasiënt bereken en ongewenste gebeure is aangeteken totdat antibiotika gestaak is en neutropenie opgeklaar het. Die risikovoorspellingstelling het ingesluit hemoglobien >9 g/dL, ’n witseltelling <0,3 g/L, ’n plaatjietelling <50 g/L, en meer intensiewe chemoterapie as instandhoudingsbehandeling vir akute limfoblastiese leukemie. Ongewenste gebeure is omskryf as ernstige mediese komplikasies, mikrobiologies omskrewe infeksie en radiologies bevestigde pneumonie. Resultate Daar was 100 episodes van koorsige neutropenie by 52 pasiënte, van wie 54% hematologiese kwaadaardighede, 44% soliede tumore en 2% tumore in die sentrale senustelsel gehad het (terugkerende kwaadaardigheid 16%). Die verhouding manlike tot vroulike pasiënte was 1,8:1 en die mediaanouderdom 56 maande (gemiddelde ouderdom 71 maande; ouderdomsbestek 8 tot 175 maande). Ongewenste gebeure het by 18 van die 57 pasiënte (45%) met ’n lae risiko (telling <9) en by 22 van die 43 pasiënte (55%) met ’n hoë risiko (telling >9) voorgekom, wat ’n sensitiwiteitswaarde van 56.8%, ’n spesifisiteitswaarde van 65%, ’n positiewe voorspellingswaarde van 50% en ’n negatiewe voorspellingswaarde van 70.9% opgelewer het. Die totale witseltelling (p = <0,01) en absolute monosiettelling (p = 0,05) het ’n beduidende verband met ongewenste gebeure getoon. Antibiotikumweerstandige mikro-organismes is in 18% van die mikrobiologies bevestigde gevalle van koorsige neutropenie aangetref. Gevolgtrekking Hoewel hierdie studie nie die risikobepalingsinstrument (Ammann-instrument) kon staaf nie, het dit die belangrike verwantskap tussen die totale witseltelling, absolute monosiettelling en ongewenste gebeure gedurende koorsige neutropenie aan die lig gebring. Daar was duidelike verskille in die pasiëntkohorte van hoëinkomstelande en dié van ’n lae- tot middelinkomsteland met ’n laer mediaanouderdom en meer weerstandige organismes.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/100401
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