Management of ETT cuff pressure is an essential aspect of nursing care of intubated patients, and the importance of complications related to undesirable cuff pressure cannot be over emphasised20. Nurses are at a patient’s bedside around the clock, and it is expected of them to be knowledgeable of the complications that can arise when the ETT cuff is under or over3,21. Adequate knowledge of practices related to the management of ETT cuff pressure is therefore imperative. The findings of this study show that, although the post-test questionnaire respondents’ knowledge of nursing care practices for the management of ETT cuff pressure was superior in both intervention groups, the overall knowledge score of most participants in both groups was low.
Our study results showed that knowledge regarding specific practices was particularly low. Firstly, fewer nurses had knowledge about the correct range of ETT cuff pressure of 22-30 mmHg. Gilliland, Perrie and Scribante22 stress that tracheal perfusion pressure estimated to be 22-30 mmHg, should not be exceeded by the ETT cuff pressure. Exceeding tracheal perfusion pressure impedes tracheal mucosa circulation, which leads to ischemia and the development of lesions. Contradicting with our results are those of a study on ICU nurses regarding the measurement of ETT cuff pressure in Brazil, where in the pre-training period, inappropriate cuff pressure measures (over 30cmH2O) during morning, afternoon and evening night shifts were shown (9.2, 11.9 and 13.7 cmH2O, respectively. During the post-training, the inappropriate cuff-pressures were less identified, and there was a significant reduction for the afternoon and evening-night shifts, respectively (p<0.001)16.
Secondly, fewer participants indicated that they would continue cuff inflation, irrespective of the volume of air inserted, or continue cuff inflation, notifying the physician in the pre-test period. Leaks of ETTs in mechanical ventilation cause a loss of volume for positive pressure ventilation and low oxygenation. Sometimes audible leaks are used as a base for monitoring ETT cuff pressure by nurses caring for mechanically ventilated patients23. Although the comparison of the groups was not statistically significant, our study revealed an improvement in nursing care practice regarding the management of audible air leaks. Literature recommends that when inflating the ETT cuff 10 mls of air should be used. However, when more than 10 mls is required, notifying the physician regarding the leak is imperative as the cuff might be damaged, thus requiring re intubation of the critically ill patient24. Our results are comparable to those of a similar study conducted in South Africa in which only 4% of 100 participants indicated that they would use 10 ml of air to inflate a leak, which is the best-recommended response, while the rest indicated incorrect responses13.
Thirdly, less than half of the participants in the post-test in both intervention groups indicated that the aspiration of gastric contents and increased chances of ventilator-associated pneumonia are all complications of under-inflation of the ETT cuff, although no statistical significant difference was seen between groups. An ETT cuff pressure below 20 cmH2O is regarded as a contributing risk factor for ventilator-associated pneumonia and ineffective positive pressure ventilation25 (Nseir et al., 2011).
Age and experience have been associated with the level of knowledge, as older practitioners have often acquired more experience, which usually translates in better knowledge outcomes26. For example, Jansson, Ala-Kokko, Ylipalossari, Syrjiala and Kyngas27 found that most nurses who had more than 5 years’ experience in ICU scored higher on scientific knowledge of evidence-based guidelines (60.4%) compared to those with less experience (53.8%). It could be argued that nurses in the current study scored generally lower in their knowledge related to nursing care practices for the management of ETT cuff pressure since they were relatively young and had less experience than the older, more experienced nurses had.
Mentoring of the younger and/or more inexperienced nurses by ‘buddying’ them with older, more experienced nurses in the ICU during shifts could assist in increasing knowledge. Mentoring has proven to have positive outcomes on patient care as well as improved job satisfaction among nurses in ICUs, as both junior and senior nurses can experience increased levels of competence, which consequently leads to a reduced attrition rate among nurses28,29. A formal mentoring programme is therefore recommended for the ICUs in this study. A mentoring programme was reported to offer a balance in the mentor’s mentoring responsibilities with his/her workload, support in terms of acknowledging the mentoring role of these nurses as well as providing access to training and knowledge in this complex environment30,31.
ICU training is also considered as being related to an increase in knowledge regarding ICU-related nursing practices. For example, in a study on ICU nurses’ knowledge of pain management, glycaemic control and weaning from mechanical ventilation, Perrie, Smchmollgruber, Bruce and Becker32 found a significant higher level of knowledge in trained ICU nurses, compared to those that were not formally trained. Further, by virtue of their training, nurses who are specialised in intensive care nursing are considered more knowledgeable regarding nursing care practices, including the management of ETT cuff pressure. In this study, less than a quarter of the participants indicated that they had undergone formal ICU training.
Although it seems to be a common practice for nurses working in ICUs in Malawi and many other lower- and middle-income countries to be trained as they work in the units33, our study showed that such in-service training may not be adequate to improve nursing care practices, specifically with regards to the management of ETT cuff pressure. Hence, this could explain the generally low knowledge scores obtained for questions regarding nursing care practices for the management of ETT cuff pressure by the nurses in this study. According to Haniffa et al.34, quality training is imperative for good quality care in the ICU. Therefore, it is recommended that nurses in ICUs should be formally trained before positioning them in these units and/or that a structured training programme should be provided to those currently without formal training but working in ICUs. Structured training programmes were found to be associated with a decrease in ICU mortality, and an improvement of other performance indicators, such as discontinuation of vasoactive drugs, earlier discontinuation of mechanical ventilation and earlier ICU discharge34.
Furthermore, continuous professional development should be encouraged by frequent in-service training on all practices related to the management of ETT cuff pressure. This is especially important as the overall knowledge score in this study was low, and for some practices, the results showed little improvement in knowledge or even a decline compared to the pre-test questionnaire. It remains unclear whether the improvement in knowledge of some practices was internalised by the nurses who participated in the study and if it would be retained. Continuous professional development, which is critically reflective, constructive, networked and supported with adequate material and technical resources according to nurses’ needs and the specific ICU context, should be maintained and encouraged35.
In Malawi, the non-availability of guidelines for the management of ETT cuff pressure in ICUs could have contributed to inadequate knowledge in this area. This explains the reason for some non-recommended practices regarding the management of ETT cuff pressure, as these guidelines are tools used to standardise treatment plans and assist health care providers in making evidence-informed clinical decisions21.
An improvement in knowledge was observed for certain practices that differed per group. For example, both intervention groups showed the most knowledge improvement regarding the complications of under-inflation of the ETT cuff pressure and the frequency of monitoring ETT cuff pressure. However, knowledge only improved significantly in the Intervention 2 group, where multiple passive and active intervention implementation strategies were employed, including a half-day educational session, printed materials and monitoring visits. Active approaches, including monitoring or site visits, have been proven particularly effective in the implementation of guidelines, but should preferably be part of a multi-faceted approach to effectively improve knowledge among practitioners36.
Several limitations were identified in the way this study was conducted. Firstly, it did not include the context of implementation, such as environmental readiness and the stakeholders involved that, according to Harvey and Kitson37, should be considered during implementation. The guidelines for the management of ETT cuff pressure in mechanically ventilated adult patients, on which the intervention was based, were reviewed to fit the ICU context in Malawi. However, this research did not consider the possible barriers and facilitators, which should be assessed in order to tailor the implementation strategies to the specific setting and target group38. Additionally, the sample size per pre- and post-group for the two groups was too small to conduct inferential statistics for the demographic variables meaningfully and made it impossible to include further variables in the analysis. The demographic differences between the pre- and post-test within both groups were due to the different samples for these groups. However, the participants within each intervention group were the same for the pre- and post-test questionnaires. Randomised sampling could have possibly be used to avoid this, but was not possible due to the already small sample. An attempt was made to include all N = 61 in the study, but participation was voluntary, thus a bigger sample could not be achieved. Furthermore, the participants’ pre- and post-test data could not be matched as participants responded anonymously.
Finally, although the management of ETT cuff pressure is mainly conducted by nurses, it forms part of a multi-disciplinary team approach. For continuity of care, the perspectives of stakeholder other than nurses, such as medical specialists or family involved in the care, could have been included in the study. A follow-up study of implementing guidelines using a variety of implementation strategies, testing a larger population and taking into consideration the contextual, demographic and stakeholder issues mentioned, would be helpful in such a complex context.