World J Surg DOI 10.1007/s00268-015-2968-x
REPLY, LETTER TO THE EDITOR
Red Cell Distribution Width Cannot Predict Acute Mesenteric Ischemia: Reply Abdullah Kisaoglu • Mucahit Emet
Ó Socie´te´ Internationale de Chirurgie 2015
To the Editor, We are honored to see that our published article about the relationship between acute mesenteric ischemia (AMI) and red cell distribution width (RDW) took attention [1]. Zhang et al. [2] shared their opinions about the topic, and they deservedly pointed out some blurred details. It is our mission to clarify these issues: First, RDW is not a specific marker, but a clue that something wrong is going on in the body leading to an increase in reticulocytes in the blood. There are hundreds of different physiologic and pathologic conditions that may cause RDW rise. In our methods section, we clearly identified that our exclusion criteria included ‘‘patients with any illness that could affect RDW levels, such as thalassemia trait, hereditary elliptocytosis, and hemoglobin C disease’’ [1]. Neither the patients with AMI nor control group had renal/ hepatic dysfunction, thyroid or bone marrow disease, previous history of transfusion within 3 months, or malnutrition. The study groups consisted of Turkish ethnicity without using medications that may influence RDW. However, we could not stabilize some of the comorbidities that were also known as etiologic factors in AMI such as atrial fibrillation, chronic heart failure, arterial hypertension, and diabetes mellitus. We mentioned this point in our limitations section [1]. Second, as the study groups were gathered from the emergency department (ED), there were no delay between blood sampling and RDW measuring. After the blood A. Kisaoglu (&) Department of General Surgery, School of Medicine, Ataturk University, 25070 Erzurum, Turkey e-mail: [email protected] M. Emet Department of Emergency Medicine, School of Medicine, Ataturk University, Erzurum, Turkey
samples are sent via pneumatic system in our ED, the parameters are measured in a special part of the laboratory to prevent delays: emergency laboratory part. Thus, we think that our laboratory procedure has got no influence in RDW measurements. Third, in our first table, there were 13 parameters that were significantly different between AMI patients and controls. We were analyzing the laboratory parameters of study population, and thus we did not take into account demographic features and comorbidities in multivariate analysis. As some of these laboratory parameters were associated with each other, we carefully chosen seven different parameters in the multivariate analysis. Studying seven parameters as multivariate analysis in a population of 159 is very acceptable and enough for the statistical power [1]. In the logistic analysis, we only gave statistically significant results. The odds ratio of RDW was 1.058 (95 % CI 0.754–1.485; wald: 0.106, p = 0.745). Fourth, Zhang et al. kindly requested the reason of conflicting results about RDW levels and ischemia/necrosis size and mortality between our study and Bilgic et al.’s study [1–3]. Our study has got superiorities discussed to the article by Bilgic et al. We measured the size of ischemia/ necrosis in centimeters, while they just grouped the patients according to approximate necrosis length without measuring the exact size. Moreover, we did not need resection surgery in the first look for all the patients with AMI contrary to their study population. Most important, we excluded patients with comorbidities that may affect RDW, and for the etiologic factors that may affect this parameter (atrial fibrillation, chronic heart failure, hypertension, and diabetes mellitus), we discussed them with univariate analyses between patients with and without mortalities. We were unable to see these exclusion criteria and discussions in the study by Bilgic et al.
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World J Surg
Last, we did not compare RDW and other prediction models or combinations of other models in our study as it would lengthen our results and would make reading confusing [1]. Our logistic regression analysis in the results section truly identified the cases with a sensitivity and specificity of 70.6 and 91.7 %, respectively, having an overall percentage of 85 %. As a result, we think that our study will aid surgeons and emergency physicians about the use of RDW in patients with abdominal pain to rule out AMI.
123
References 1. Kisaoglu A, Bayramoglu A, Ozogul B et al (2014) Sensitivity and specificity of red cell distribution width in diagnosing acute mesenteric ischemia in patients with abdominal pain. World J Surg 38:2770–2776. doi:10.1007/s00268-014-2706-9 2. Jiang L, Ma Y, Zhang M (2014) Can red cell distribution width predict acute mesenteric ischemia? World J Surg. doi:10.1007/ s00268-014-2815-5 3. Bilgic I, Dolu F, Senol K et al (2014) Prognostic significance of red cell distribution width in acute mesenteric ischemia. Perfusion. doi:10.1177/0267659114534289
REPLY, LETTER TO THE EDITOR
Red Cell Distribution Width Cannot Predict Acute Mesenteric Ischemia: Reply Abdullah Kisaoglu • Mucahit Emet
Ó Socie´te´ Internationale de Chirurgie 2015
To the Editor, We are honored to see that our published article about the relationship between acute mesenteric ischemia (AMI) and red cell distribution width (RDW) took attention [1]. Zhang et al. [2] shared their opinions about the topic, and they deservedly pointed out some blurred details. It is our mission to clarify these issues: First, RDW is not a specific marker, but a clue that something wrong is going on in the body leading to an increase in reticulocytes in the blood. There are hundreds of different physiologic and pathologic conditions that may cause RDW rise. In our methods section, we clearly identified that our exclusion criteria included ‘‘patients with any illness that could affect RDW levels, such as thalassemia trait, hereditary elliptocytosis, and hemoglobin C disease’’ [1]. Neither the patients with AMI nor control group had renal/ hepatic dysfunction, thyroid or bone marrow disease, previous history of transfusion within 3 months, or malnutrition. The study groups consisted of Turkish ethnicity without using medications that may influence RDW. However, we could not stabilize some of the comorbidities that were also known as etiologic factors in AMI such as atrial fibrillation, chronic heart failure, arterial hypertension, and diabetes mellitus. We mentioned this point in our limitations section [1]. Second, as the study groups were gathered from the emergency department (ED), there were no delay between blood sampling and RDW measuring. After the blood A. Kisaoglu (&) Department of General Surgery, School of Medicine, Ataturk University, 25070 Erzurum, Turkey e-mail: [email protected] M. Emet Department of Emergency Medicine, School of Medicine, Ataturk University, Erzurum, Turkey
samples are sent via pneumatic system in our ED, the parameters are measured in a special part of the laboratory to prevent delays: emergency laboratory part. Thus, we think that our laboratory procedure has got no influence in RDW measurements. Third, in our first table, there were 13 parameters that were significantly different between AMI patients and controls. We were analyzing the laboratory parameters of study population, and thus we did not take into account demographic features and comorbidities in multivariate analysis. As some of these laboratory parameters were associated with each other, we carefully chosen seven different parameters in the multivariate analysis. Studying seven parameters as multivariate analysis in a population of 159 is very acceptable and enough for the statistical power [1]. In the logistic analysis, we only gave statistically significant results. The odds ratio of RDW was 1.058 (95 % CI 0.754–1.485; wald: 0.106, p = 0.745). Fourth, Zhang et al. kindly requested the reason of conflicting results about RDW levels and ischemia/necrosis size and mortality between our study and Bilgic et al.’s study [1–3]. Our study has got superiorities discussed to the article by Bilgic et al. We measured the size of ischemia/ necrosis in centimeters, while they just grouped the patients according to approximate necrosis length without measuring the exact size. Moreover, we did not need resection surgery in the first look for all the patients with AMI contrary to their study population. Most important, we excluded patients with comorbidities that may affect RDW, and for the etiologic factors that may affect this parameter (atrial fibrillation, chronic heart failure, hypertension, and diabetes mellitus), we discussed them with univariate analyses between patients with and without mortalities. We were unable to see these exclusion criteria and discussions in the study by Bilgic et al.
123
World J Surg
Last, we did not compare RDW and other prediction models or combinations of other models in our study as it would lengthen our results and would make reading confusing [1]. Our logistic regression analysis in the results section truly identified the cases with a sensitivity and specificity of 70.6 and 91.7 %, respectively, having an overall percentage of 85 %. As a result, we think that our study will aid surgeons and emergency physicians about the use of RDW in patients with abdominal pain to rule out AMI.
123
References 1. Kisaoglu A, Bayramoglu A, Ozogul B et al (2014) Sensitivity and specificity of red cell distribution width in diagnosing acute mesenteric ischemia in patients with abdominal pain. World J Surg 38:2770–2776. doi:10.1007/s00268-014-2706-9 2. Jiang L, Ma Y, Zhang M (2014) Can red cell distribution width predict acute mesenteric ischemia? World J Surg. doi:10.1007/ s00268-014-2815-5 3. Bilgic I, Dolu F, Senol K et al (2014) Prognostic significance of red cell distribution width in acute mesenteric ischemia. Perfusion. doi:10.1177/0267659114534289
