# Pneumonia Associated with Mechanical Ventilation: Management and Preventive Aspects
## 4 Discussion  
The studies used in this systematic review show us information and results on various aspects of VAP. Regarding the use and effectiveness of the different preventive measures, we can find different results depending on each measure:  
Figure 1: Results adherence and knowledge of nursing staff according to various studies [53; 54; 56; 57; 58]. All the authors that make up the review shared measures such as hand hygiene with soap and water and the introduction of 70% alcoholic solutions. Handwashing would thus help prevent the spread of infection and remove microbes from the hands. Oropharyngeal hygiene and oral care with chlorhexidine is one of the most important and widely used measures. All authors agree that concentrations such as 0.12%, 0.2% or 2% chlorhexidine should be used. Chlorhexidine would thus be considered the most evaluated antiseptic in clinical trials and the one that most frequently helps reduce microbial colonization of the oral cavity and therefore reduce the incidence of VAP. Authors such as [PERSON] et al. [34] and [PERSON] et al. [38] report that the use of toothbrushing presents controversy and little proven evidence. On the other hand, [PERSON] et al. [46] comment that the use of dental brushing does not seem to be harmful, so it could be used during oral hygiene. Regarding the frequency of hygiene of the oral cavity, authors such as [PERSON] et al. [37], [PERSON] et al. [36], [PERSON] et al. [40] and [PERSON] et al. [43] agree that this should be done every 8h or once per shift. The pressure of the cuff will be one of the main factors involved in the etiology of VAP. Low pressures will allow secretions and microorganisms to enter the lower respiratory tract from the oropharynx, and excessively high pressures will damage the tracheal mucosa, producing ischemia. All the authors involved in this review agree that the cuff should have a minimum pressure of 20 cm H\({}_{2}\)O. Regarding the maximum pressure, there has been more controversy. Authors, such as [PERSON] et al. [32], [PERSON] et al. [35], [PERSON] et al. [36], [PERSON] et al. [37], [PERSON] et al. [39], [PERSON] et al. [40] and [PERSON] et al. [43], agree that the maximum pressure should be 30 cm H\({}_{2}\)O. Others, such as [PERSON] et al. [38] and [PERSON] et al. [45], consider that it should be a maximum of 35 cm H\({}_{2}\)O. Regarding the suction of secretions, most agree that it should be used when necessary and not routinely. Always using the most aseptic and sterile technique possible, avoiding system disconnections as much as possible. Authors, such as [PERSON] et al. [32], [PERSON] et al. [33] and [PERSON] et al. [43], recommend the use of closed suction systems since they would cause greater comfort when performing the technique and thus avoid disconnections and openings of the system, although they are associated with greater colonization. [PERSON] et al. [34] and [PERSON] et al. [40] do not show differences in terms of suction systems, considering that there is no clear evidence regarding the use of one or the other. According to the authors, the open system would cause greater desaturation and instability in the patient, and the closed system would entail a higher cost. Aspiration of bronchial secretions should be limited to situations in which there is clinical evidence of the presence of secretions: characteristic noises on auscultation, impaired ventilatory function, altered flow-volume-pressure curve parameters, etc. The position of the patient constitutes a basic preventive measure. All authors agree that the supine position at 0\({}^{\circ}\) should be avoided and that the head of the bed should be kept between 30-45\({}^{\circ}\) in order to avoid gastroesophageal reflux and the probable consequent aspiration of gastric content, as well as to prevent any secretion from passing into the airway. ETT with drainage of subglottic secretions is a preventive measure on the rise.