Despite of the availability of many severity scores systems that can predict the mortality, there were only few studies that assess the mortality and morbidity in PICU in critically ill patients presented with hypoalbuminemia. This study focused on the incidence of hypoalbuminemia in PICU in critically ill pediatrics, as hypoalbuminemia is a common problem associated with higher mortality and morbidity rate . In critical illness, the permeability of blood vessels increases much by the action of inflammatory mediators, as a result, there is a dramatic change in albumin level between extra-vascular and intra-vascular. There is about 300% rise in albumin escape rate as a result of albumin balance alteration. Also, there is a huge decrease in albumin synthesis in liver by the effect of these inflammatory mediators especially IL-6 and TNF-alpha [7, 14].
The incidence of hypoalbuminemia in this study was 44.6% of children admitted to the PICU and this comes with the alignment of a study by (Horowitz and Tai 2007) that mentioned the incidence of hypoalbuminemia which was about 33% at admission . (Durward et al. 2003) found that hypoalbuminemia was 57% at admission but after 1 day, it was progressed to 76% . The frequency of hypoalbuminemia in another study by (Tiwari et al. 2014) was 21% at admission, then it increased to 34% after one week, and about 37% during the rest of the PICU stay . We couldn’t perform repeated serum albumin to all children due to the lack of commitment from guardians, so we measured only the incidence of hypoalbuminemia at admission.
We used PIM2, PRISM2 and PELOD2 scores to assess the severity of illness 48-h postadmission [15–17]. Pediatric Index of Mortality 2 (PIM2) was found in a previous study by (Qureshi et al. 2007) to be the most effective pediatric scoring system with the highest accuracy rate among all other scores . Pediatric Risk of mortality 2 (PRISM2) and Pediatric Logistic Organ Dysfunction 2 (PELOD2) were also used to assess the severity of illness and give the highest accuracy rate in assessing the risk mortality as well.
There was a strong relation between hypoalbuminemia and mortality rate as PRISM2 score was much higher in the hypoalbuminemic group rather than the normal albumin level group (10.82 vs 7.71, p = 0.13) despite of the non-statistically significance in p-value, and high PELOD2 score in the hypoalbuminemic group versus the other group (3.24 vs 1.35, p = 0.04). As regards the need for mechanical ventilation, there was a highly significant difference in favor of the hypoalbuminemic group (56% vs 21.9% p < 0.001) and a high mortality rate in the hypo albumin level group compared to the normal group (43.9% vs 15.8% p < 0.001). This comes with the alignment of another study by (Tiwari et al. 2007) which stated that hypoalbuminemic children had higher PRISM2 scores compared to normal ones (12.9 vs 7.5, P < 0.001) with prolonged PICU stay (13.8 vs 6.7, p < 0.001); and a higher need for mechanical ventilation was observed in the hypoalbuminemic group compared to normal group (84.8% vs 28.8%, p < 0.001) and a high risk of mortality between both groups in favor of hypoalbuminemic group (25.6% vs 17.7% p < 0.001) .
Our findings on PRISM2 score offered good discriminative power with the area under the ROC curve being 0.73 (95% CI, [0.638–0.822]) which comes in alignment with other studies that mentioned the ROC curve analysis of PRISM (0.78, 0.90, 0.87, 0.86, 0.95) as mentioned by (Qureshi et al. 2007, Pollack et al. 2016, Martha et al. 2005, Verma et al. 2017, and Choi et al 2005, respectively) [17–21]. Also there was a significant correlation between PELOD2 score and PIM2 score with (0.84, 95% CI, [0.767–0.921]; and 0.78, 95% CI, [0.691–0.86] respectively, p < 0.001). So overall these three scores rendered good discriminative relation between survivors and non-survivors and further it may be used as a tool for prognostic evaluation beside their use in assessing the risk of mortality.
4.1 Limitations and Recommendations:
This study had several limitation. It was a single-center study with a small number of participants in each group. Also we couldn’t perform repeated serum albumin so we can assign the incidence of hypoalbuminemia in whole study duration. We recommend further high number of participants and multi-center studies to be approached, so we can conclude a better evaluation of such disease. We also recommend prospective studies and randomized controlled trials to be performed not retrospective, so we can get the highest possible accuracy.