Menoufia Medical Journal

ORIGINAL ARTICLE
Year
: 2020  |  Volume : 33  |  Issue : 3  |  Page : 862--867

Incidence of hyponatremia in acute bronchiolitis


Ahmed A Khatab1, Salem El Sayed Deraz1, Wael A Bahbah1, Haitham Y Hassbou2,  
1 Department of Pediatrics, Faculty of Medicine, Menoufia University, Menoufia, Egypt
2 Department of Pediatrics, Ministry of Health, Tanta, Egypt

Correspondence Address:
Haitham Y Hassbou
Department of Pediatrics, Ministry of Health, Tanta
Egypt

Abstract

Objective To assess the incidence and early detection of hyponatremia (below 135 mmol/l) associated with acute bronchoilitis in infants. Background Acute bronchiolitis is the most common disease of lower respiratory tract during the first year of life. It occurs as an annual epidemic in winter, and it often affects the child's ability to feed. Hyponatremia is a prognostic factor that might predict the disease course of children with severe bronchiolitis. Patients and methods This study was conducted on 300 patients having acute bronchiolitis from February 2015 to February 2016. They were divided into two groups: group I included 240 patients with normal serum sodium level (135–145 mmol/l), and group II consisted of 60 patients with low serum sodium level (<135 mmol/l). Detailed history; routine, physical examination; length of hospital stay; and clinical severity scores were done. Results There was a highly significant statistical difference regarding length of stay in hospital (P = 0.001) and clinical scores on days 3 and 5 (P = 0.001 for both). There was a highly significant positive correlation between chest radiography and length of stay in hospital (r = 0.441, P = 0.001). There was a significant negative correlation between family history of allergy and length of stay in hospital in normonatremic patients (r = −0.238, P = 0.008), as well as a negative correlation between age and length of stay in hospital (r = −0.241, P = 0.007). Conclusion Hyponatremia on the day of hospitalization was associated with a higher severity of disease. It is a prognostic factor that might improve our ability to predict the disease course of children with severe bronchiolitis. Serum sodium should be measured in all patients with bronchiolitis within 48 h from admission. Further studies are needed to assess the incidence of hyponatremia in bronchiolitis on a broad scale and to follow-up the course of the disease.



How to cite this article:
Khatab AA, Deraz SE, Bahbah WA, Hassbou HY. Incidence of hyponatremia in acute bronchiolitis.Menoufia Med J 2020;33:862-867


How to cite this URL:
Khatab AA, Deraz SE, Bahbah WA, Hassbou HY. Incidence of hyponatremia in acute bronchiolitis. Menoufia Med J [serial online] 2020 [cited 2024 Mar 28 ];33:862-867
Available from: http://www.mmj.eg.net/text.asp?2020/33/3/862/296675


Full Text



 Introduction



Acute bronchiolitis is the most common disease of lower respiratory tract during the first year of life. It occurs as an annual epidemic in winter, and it often affects the child's ability to feed. The etiology is viral, with respiratory syncytial virus (RSV) being the commonest agent. Respiratory symptoms remain generally mild, which may only last for a few days, and the treatment is only supportive and at home care. Certain infants are at high risk of severe illness (age <3 months, preterm birth, neonatal respiratory disease, bronchopulmonary dysplasia, and underlying chronic diseases) and require hospitalization [1]. It is generally accepted that acute bronchiolitis refers to the first episode of acute wheezing in children less than 2 years of age, starting as a viral upper respiratory infection (coryza, cough, or fever) [2],[3]. Electrolytes should be determined in infants with bronchiolitis who are dehydrated [4]. Hyponatremia is associated with bronchiolitis especially severe forms, associated with administration of intravenous fluids together with increased antidiuretic hormone values. The physicians should be familiar with the signs and symptoms of extrapulmonary manifestations of RSV infections and suspect it in all preterm infants, especially those who did not receive palivizumab prophylaxis [5].

Hyponatremia in children with bronchiolitis admitted to ICU is associated with worse outcome [6]. Hyponatremia is a prognostic factor that might improve the ability to predict the disease course of children with severe bronchiolitis [7]. Hypotonic intravenous fluid administration is associated with hyponatremia [8]. In response to cases of fatal hyponatremia, the National Patient Safety Agency recently issued an alert aimed at reducing the risk of hyponatremia in children; it recommended that electrolytes should be determined before starting intravenous fluid therapy and at least daily afterward. Fluids should be restricted in children with hyponatremia who are receiving intravenous 0.9% saline (with 5% dextrose) and who have high antidiuretic hormone values [9]. The aim of this study was to assess the incidence and early detection of hyponatremia (below 135 mmol/l) associated with acute bronchoilitis in infants.

 Patients and Methods



This study was conducted on 300 patients having acute bronchiolitis diagnosed by both clinical and laboratory criteria. They were enrolled from Pediatric Department, Menoufia University, and El-Santa Central Hospital, after approval by the local medical ethical committee. Patients were selected during the study period from February 2015 to February 2016, and all study patients were divided into two groups based on measured serum sodium concentration within 48 h of the day of hospitalization: group I included 240 patients with normal serum sodium level (135–145 mmol/l). They had normonatremia followed till clinical improvement or a maximum of 5 days. Group II included 60 patients with low serum sodium level (<135 mmol/l). They had hyponatremia followed till clinical improvement or a maximum of 5 days.

Ethical consideration

The study was approved by the ethical committee of Menoufia Faculty of Medicine, and an informed consent was obtained from all patients' guardians before the study was commenced.

Selection criteria for patients

Inclusion criteria were infants diagnosed as having acute bronchiolitis (males and females) and aged from 2 months to 2 years. Exclusion criteria were patients with recurrent wheeze and preexisting risk factors for hyponatremia (diuretic therapy, cardiac diseases, renal disease, and hypothyroidism).

All patients were subjected to the following: detailed history, including personal, present, past, and family history, such as age, consanguinity, and history of upper respiratory tract viral infection (fever, rhinorrhea, cough, or sneezing); clinical examination including general appearance such irritable, calm, alert, or lethargic, vital signs, and manifestations of respiratory distress (working ala nasi, subcostal and intercostal retraction, grunting, cyanosis); chest examination (inspection: increased anteroposterior diameter of chest, subcostal, and intercostal retraction; palpation: shifting of trachea and tactile vocal fremitus; percussion: hyperresonance of chest; and auscultation: vesicular breath sounds, rhonchi, and crepitations); and chest radiography poster-anterior view. Types of outcome measures were length of hospital stay and clinical severity scores. Clinical scoring system in bronchiolitis was used according to Ayten et al. [10] [Table 1], where the sum of points gives the clinical score as follow:{Table 1}

Statistical analysis

Results were tabulated and statistically analyzed by a personal computer using Microsoft Excel 2016 and SPSS, version 23 (SPSS Inc., Chicago, Illinois, USA). Statistical analysis was done using descriptive, for example, percentage (%), mean, and SD, and analytical, including χ2, t test, Fisher's exact test, and Pearson's correlation coefficient (r). A value of P value less than 0.05 was considered statistically significant.

 Results



There was no statistically significant difference between normonatremic and hyponatremic patients regarding demographic data [Table 2].{Table 2}

The current study shows that there was no statistically significant difference between normonatremic and hyponatremic patients regarding clinical data on admission [Table 3].{Table 3}

There was a highly significant statistical difference between normonatremic and hyponatremic patients regarding length of stay in hospital (P = 0.001) and clinical scores on days 3 and 5 (P = 0.001 for both). However, there were no statistically significant differences between normonatremic and hyponatremic patients regarding clinical score (P = 0.33). Moreover, 196 normonatremic patients (81.5%) had normal radiography, and 42 (17.5%) patients had hyperinflated chest radiography, and two (0.8%) patients showed collapse on radiography. However, only 32 (53%) hyponatremic patients had normal radiography, 28 (47%) patients had hyperinflated chest on radiography, and no one showed collapse in group II on radiography [Table 4].{Table 4}

Additionally, the current study showed that there was a nonsignificant negative correlation between age and clinical score on day 1 (r = −0.035, P = 0.702) and day 3 (r = −0.176, P = 0.51) as well as between family history of allergy and length of stay in hospital in hyponatremic group (r = −0.067, P = 0.722). There was a highly significant positive correlation between chest radiography and length of stay in hospital (r = 0.441, P = 0.001). There was a significant negative correlation between family history of allergy and length of stay in hospital in normonatremic patients (r = −0.238, P = 0.008) as well as a negative correlation between age and length of stay in hospital (r = −0.241, P = 0.007) [Table 5] and [Figure 1], [Figure 2], [Figure 3], [Figure 4].{Table 5}{Figure 1}{Figure 2}{Figure 3}{Figure 4}

 Discussion



The present work showed that there was no significant statistical difference between normonatremic patients and hyponatremic patients regarding demographic data. In normonatremic group, the data were as follows: the mean age was 4.8 ± 99 months, 144 (60.5%) patients were males and 96 (39.5%) patients were females, and 19 (7.9%) patients had positive family history of allergy and 222 (92.1%) had negative family history of allergy. In hyponatremic group, the data were as follows: the mean age was 4.5 ± 85 months, 30 (50%) patients were males and 30 (50%) patients were females, and seven (11.7%) patients had positive family history of allergy and 53 (88.3%) had negative family history of allergy. A study by Hasegawa and colleagues showed that hyponatremia on the day of hospitalization was associated with a higher severity of disease. Hyponatremia is a prognostic factor that might improve the ability of clinicians to predict the disease course of children with severe bronchiolitis. They found that among the children hospitalized in the ICU for bronchiolitis, 193 (84%) were categorized into the normonatremic group and 38 (16%) into the hyponatremic group. Compared with children with normonatremia, those with hyponatremia had higher risks of mechanical ventilation (40 vs. 58%; P = 0.04) [7].

Our study showed that there was no significant statistical difference between normonatremic patients and hyponatremic patients regarding clinical data on admission.

The study conducted by Hasegawa et al. [7] showed that infants in the hyponatremic group had a clinically relevant increase in ICU length of stay (2.2 days) compared with normonatremic patients (P = 0.005). Moreover, Michael et al. [11] showed that hyponatremic children had longer ICU LOS (9.5 ± 5.2 days) compared with normonatremia (3.8 ± 3.6 days) (P < 0.0002). Furthermore, Shein and colleagues showed that blood sodium levels correlated negatively with hospital length of stay (r = −0.477, P < 0.0001). On each of the first 4 days of hospitalization, significantly increased hospital length of stay was observed in patients with hyponatremia (n = 134, 25.7% of patients with available sodium data) versus patients with normonatremia (n = 387, 74.3%), and in patients prescribed intravenous fluid (IVF) less than 70 (n = 348, 46.3% of patients prescribed IVF) versus patients prescribed IVF more than or equal to 70 (n = 403, 53.7%). Patients prescribed IVF less than 70 had increased rates of hyponatremia on the subsequent day versus patients prescribed IVF more than or equal to 70 (50.0 vs. 26.9%, P < 0.001) [12].

Our study showed that there was a highly significant statistical difference between normonatremic and hyponatremic patients regarding length of stay in hospital and clinical scores on days 3 and 5. However, there were no statistically significant differences between normonatremic and hyponatremic patients regarding clinical score on the day of admission. Similar results were obtained by Shaw and colleagues who showed in a prospective cohort of 228 infants designed to predict mild disease (defined as alert, active, and able to take fluids throughout their disease, no O2 therapy, etc.) versus severe disease (defined as all others without mild disease) that 58% had hyperaeration and 9% had atelectasis. The high percentage of patients with hyperaeration and collapse in Shaw study may be owing to the high number of participants in the study (N = 228) and the inclusion of high percentage of severe cases in the study [13].

Our study showed that 101 (81.5%) patients had normal chest radiography result, 21 (17.7%) patients had hyperinflated chest radiography result, and two (0.8%) patients had collapse in chest radiography result. Among the controls, 21 (70%) had normal chest radiography result, nine (30%) controls had hyperinflated chest radiography result, and no controls (0.0%) had collapse in chest radiography result. In the same line, Papofoll et al. [14] enrolled 310 infants with bronchiolitis and showed that severity was predicted by young age and RSV carriage. Moreover, the study by Giovanni et al. [15], which enrolled 145 infants with bronchiolitis, showed that the major predictor for severe disease that requires hospitalization was low chronological age at the beginning of RSV season. In addition, Joseph et al. showed that age was found to be a significant factor in the severity of infection. The younger the infant, the more severe the infection [16].

Our study showed that there was a nonsignificant negative correlation between age and clinical scores on day 1 and day 3 as well as between family history of allergy and length of stay in hospital in hyponatremic group. There is a highly significant positive correlation between chest radiography and length of stay in hospital. There was a significant negative correlation between family history of allergy and length of stay in hospital in normonatremic patients as well as negative correlation between age and length of stay in hospital. These results are in agreement with a prospective cohort of 228 infants designed by Shaw et al., to predict mild disease (defined as alert, active, and able to take fluids throughout their disease, no O2 therapy, etc.) versus severe disease (defined as all others without mild disease), where 58% had hyperaeration and 9% had atelectasis. The patients with atelectasis were 2.7 times more likely to have severe disease and longer length of stay than those without this radiography film finding. This association persisted when it was included in a multivariable analysis [13].

In contrast, the data from cohort design of Dawson, specifically to look at the utility of routine chest radiography in bronchiolitis by examining the relationship between clinical assessment (i.e., mild, moderate, severe, or very severe) and chest radiography findings (i.e., hyperinflation, atelectasis, and infiltrates) demonstrated no correlation between chest radiography film findings and baseline disease severity and length of stay [17]. However, the study done by Dawson included a small number of patient (n = 153) [17]. This was in contrast to Shaw et al., who included 228 patients in their study. Moreover, Trefny et al. [18] in a study that included 172 patients younger than 12 months, which aimed to investigate the influence of family history of allergy on the clinical course of RSV infection in ambulatory and hospitalized infants, showed that inpatients with an atopic family history had a significantly longer hospital stay than those without such a history (7.4 ± 3.7 days and 6.1 ± 2.3 days, respectively, P < 0.04) [13]. In contrast, Figueras and colleagues in a case–control study of the risk factors linked to RSV infection requiring hospitalization in premature infants born at a gestational age of 33–35 weeks in Spain found that family history of wheezing did not increase the risk of RSV-related respiratory infection and length of hospitalization; however, this may be in premature infants only [19]. Moreover, Joseph et al. [16] found that underlying comorbidities and young age remain the most important predictors for severe bronchiolitis and thereby the length of stay in hospital. However, Papofoll et al. [14] in a study that enrolled 310 infants with bronchiolitis found that severity and longer period of stay in hospital were highly correlated with younger age.

 Conclusion



Hyponatremia on the day of hospitalization was associated with a higher severity of disease. It is a prognostic factor that might improve the ability of clinicians to predict the disease course of children with severe bronchiolitis. Serum sodium should be measured in all patients with bronchiolitis within 48 h from the day of admission. Further studies are needed to assess the incidence of hyponatremia in bronchiolitis on a broad scale and follow-up the course of the disease.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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