OBJECTIVES: This study aimed to validate pulse CO-oximetry-based haemoglobin (Hb) estimation in children and adults with thalassaemia major (TM) and to determine the impact of different baseline variables on the accuracy of the estimation. METHODS: This observational study was conducted over a five-week period from March to April 2012. A total of 108 patients with TM attending the daycare thalassaemia centre of a tertiary care hospital in Muscat, Oman, were enrolled. Spot (Sp) Hb measurements were estimated using a Pronto-7(®) pulse CO-oximetry device (Masimo Corp., Irvine, California, USA). These were compared to venous samples of Hb using the CELL-DYN Sapphire Hematology Analyzer (Abbott Diagnostics, Abbott Park, Illinois, USA) to determine the reference (Ref) Hb levels. A multivariable linear regression model was used to assess the impact of baseline variables such as age, gender, weight, height, Ref Hb and blood pressure on the Hb estimations. RESULTS: Of the 108 enrolled patients, there were 54 males and 54 females with a mean age of 21.6 years (standard deviation [SD] = 7.3 years; range: 2.5-38 years). The mean Ref Hb and Sp Hb were 9.4 g/dL (SD = 0.9 g/dL; range: 7.5-12.3 g/dL) and 11.1 g/dL (SD = 1.2 g/dL; range: 7.5-14.7 g/dL), respectively. The coefficient of determination (R(2)) was 21% with a mean difference of 1.7 g/dL (SD = 1.1 g/dL; range: -0.9-4.3 g/dL). In the multivariable model, the Ref Hb level (P = 0.001) was the only statistically significant predictor. CONCLUSION: The Pronto-7(®) pulse CO-oximetry device was found to overestimate Hb levels in patients with TM and therefore cannot be recommended. Further larger studies are needed to confirm these results.
OBJECTIVES: This study aimed to validate pulse CO-oximetry-based haemoglobin (Hb) estimation in children and adults with thalassaemia major (TM) and to determine the impact of different baseline variables on the accuracy of the estimation. METHODS: This observational study was conducted over a five-week period from March to April 2012. A total of 108 patients with TM attending the daycare thalassaemia centre of a tertiary care hospital in Muscat, Oman, were enrolled. Spot (Sp) Hb measurements were estimated using a Pronto-7(®) pulse CO-oximetry device (Masimo Corp., Irvine, California, USA). These were compared to venous samples of Hb using the CELL-DYN Sapphire Hematology Analyzer (Abbott Diagnostics, Abbott Park, Illinois, USA) to determine the reference (Ref) Hb levels. A multivariable linear regression model was used to assess the impact of baseline variables such as age, gender, weight, height, Ref Hb and blood pressure on the Hb estimations. RESULTS: Of the 108 enrolled patients, there were 54 males and 54 females with a mean age of 21.6 years (standard deviation [SD] = 7.3 years; range: 2.5-38 years). The mean Ref Hb and Sp Hb were 9.4 g/dL (SD = 0.9 g/dL; range: 7.5-12.3 g/dL) and 11.1 g/dL (SD = 1.2 g/dL; range: 7.5-14.7 g/dL), respectively. The coefficient of determination (R(2)) was 21% with a mean difference of 1.7 g/dL (SD = 1.1 g/dL; range: -0.9-4.3 g/dL). In the multivariable model, the Ref Hb level (P = 0.001) was the only statistically significant predictor. CONCLUSION: The Pronto-7(®) pulse CO-oximetry device was found to overestimate Hb levels in patients with TM and therefore cannot be recommended. Further larger studies are needed to confirm these results.
Authors: M Al-Khabori; A Al-Hashim; Z Jabeen; K Al-Farsi; M Al-Huneini; A Al-Riyami; N Al-Kemyani; S Daar Journal: Int J Lab Hematol Date: 2013-03-11 Impact factor: 2.877