To the Editor,
Despite advances in the pathogenesis, antimicrobial therapy and current preventive measures, ventilator-associated pneumonia (VAP) remains as one of the most important and common complications in mechanically ventilated patients. Development of VAP can lead to increased risk of morbidity, duration of mechanical ventilation and length of intensive care unit (ICU) stay in patients. On the other hand, VAP increases the risk of 30-day mortality by 38% in mechanically ventilated ICU patients [
[1]
]. Therefore, it is very important and reasonable to consider additional preventive and therapeutic strategies to reduce mortality and improve the prognosis of critically ill mechanically ventilated patients, especially in patients with increased risk of VAP development.It has been previously confirmed that zinc, as an essential micronutrient, plays an essential role in immune function. There is growing evidence that zinc deficiency is associated with dysfunction of the immune system and increased susceptibility to various infections [
[2]
]. Additionally, it has been clearly shown that zinc deficiency is prevalent among critically ill ICU patients. However, most of these patients usually do not receive any zinc supplementation, despite the low serum zinc level. Previous studies have proven the efficacy of zinc supplementation in the prevention of pneumonia in children and older adults. Also, it has been revealed a low serum level of zinc in patients with pneumonia. Saleh et al. showed that the incidence of severe pneumonia was significantly higher in patients with less than normal zinc plasma levels compared to patients with normal serum zinc levels [[3]
].Despite this, there is very little scientific evidence to support the relationship between serum zinc levels and VAP development in mechanically ventilated ICU patients. In a secondary analysis of a prospective observational study by Hasanzadeh Kiabi et al., it has been shown that among adults mechanically ventilated trauma patients who received zinc supplements during the ICU stay, the incidence of VAP was significantly lower than other ventilated patients [
[4]
]. Also, Boudreault et al. revealed the critical role of zinc in improving the lung's tolerance for mechanical ventilation and the potential biochemical effects of zinc deficiency in the occurrence of ventilator-induced lung injury [- Hasanzadeh Kiabi F.
- Alipour A.
- Darvishi-Khezri H.
- Aliasgharian A.
- Emami Zeydi A.
Zinc supplementation in adult mechanically ventilated trauma patients is associated with decreased occurrence of ventilator-associated pneumonia: A secondary analysis of a prospective, observational study.
Indian J Crit Care Med. 2017; 21: 34-39
[5]
].Considering the importance of zinc in maintaining optimal immune function and possible worsening of zinc deficiency in critically ill patients, it seems that zinc supplementation can be considered as a potentially simple, practical, and low-cost preventive measure for VAP in mechanically ventilated patients. However, further studies are warranted to determine the efficacy of zinc supplementation and its optimal dose for the prevention of VAP among critically ill mechanically ventilated patients.
Declaration of competing interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
References
- Ventilator-associated pneumonia in adults: a narrative review.Intensive Care Med. 2020; 46: 888-906
- Zinc and its role in immunity and inflammation.Autoimmun Rev. 2015; 14: 277-285
- Relationship between plasma levels of zinc and clinical course of pneumonia.Tanaffos. 2017; 16: 40-45
- Zinc supplementation in adult mechanically ventilated trauma patients is associated with decreased occurrence of ventilator-associated pneumonia: A secondary analysis of a prospective, observational study.Indian J Crit Care Med. 2017; 21: 34-39
- Zinc deficiency primes the lung for ventilator-induced injury.JCI Insight. 2017; 2e86507
Article info
Publication history
Published online: October 11, 2021
Accepted:
October 5,
2021
Received:
October 4,
2021
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© 2021 The Author(s). Published by Elsevier Ltd on behalf of European Society for Clinical Nutrition and Metabolism.
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