Clinical characteristics and determinants of invasive mechanical ventilation outcome in adult intensive care unit in Northern Ethiopia: A resource-limited setting

INTRODUCTION

Widely available and advanced in developed countries, critical care in resource-limited settings remains scarce and substandard.^[1] As a result, treating critically ill patients in such a setting is challenging resulting in a high rate of mortality from treatable diseases.^[2] Critical care faces the same challenges as other aspects of health care in the developing world. However, the provision of critical care services in developing countries is met with additional challenges. It is either inaccessible or complicated to provide due to a lack of technology and other resources, lack of context-specific evidence for decision-making, high cost associated with running intensive care unit (ICU), and institutional barriers to the implementation of lifesaving interventions.^[2,3] In the developing world, patients requiring ICU care are generally younger and with less comorbidity, giving a remarkable opportunity to salvage more lives, arguably much more so than in the Western world.^[3]

Mechanical ventilation (MV) is an integral part of critical care.^[4] Among the millions of patients admitted to ICU globally, approximately one-third receive MV.^[5] It is the most frequent reason patients are admitted and is one of the most commonly employed interventions in the ICU.^[5,6] MV reduces the work of breathing and improves gas exchange in critically ill patients with acute hypoxemic respiratory failure and ventilatory failure. About 40% and 53% of patients admitted to ICU in Egypt and Ethiopia, respectively, receive MV;^[7,8] rates reflective of ICU patient admissions at a later stage of their disease requiring higher rates of MV usage in resource-limited settings.

However, countless preventable deaths occur in low-income countries primarily due to a lack of functioning ventilators.^[9] The provision of MV is continually saving lives in developed countries; however, deaths continue to occur in developing countries due to a combination of factors that hamper access to MV or pose impediments to the quality of critical care.^[1]

Only a few ICUs are available in resource-poor settings.^[10] ICUs in Ethiopia are constrained by considerable deficiencies in emergency drugs and essential equipment.^[11] In 2020, more than 10 countries in Africa had no mechanical ventilators.^[12] In recent years, the Ethiopian government has endeavored to open additional ICUs but mechanical ventilators remain limited in number.^[13] The lack of ICU beds and mechanical ventilators is prevalent in our setting.^[14]

MV in the ICU is associated with significant adverse effects and complications, some related to the critical care of the mechanically ventilated patient including, pain, discomfort, delirium, sleep disruption, immobility, infections (ventilator-associated pneumonia [VAP]) and ICU-acquired weakness, and others attributable to the ventilator itself.^[5,15] A constellation of adverse effects and complications may be associated with MV use, although, in many instances, the causal role of the ventilator itself has not been established.^[16]

Despite the availability of limited MV services in health-care facilities in Ethiopia, only a few studies have explored patient outcomes with the use of this intervention. Moreover, only a few studies are available on the use of MV in an African setting. This study aims to assess clinical characteristics and determinants of invasive MV outcomes in adult ICUs in North Ethiopia.

MATERIALS AND METHODS

RESULTS

DISCUSSION

This study revealed that 36.7% of the patients who were admitted to the critical care unit at ACSH during the study period received invasive MV. This was comparable to invasive MV usages in Egypt and India which showed rates of 34.5% and 31.5%, respectively.^[8,15] This was also consistent with the rate of 33% in a multinational study involving the United States, Canada, Europe, and Latin America conducted by Esteban et al.^[7] However, invasive MV use was lower than in a previous study in a similar setting in Ethiopia, which showed a rate of 47.7%.^[9] The increased rate might be associated with the fact that the latter ICU was only for surgical patients which mandates liberal use of MV for many surgical patients including post-thoracic surgeries as prophylaxis for 24 h.

The leading indications for invasive MV in this study were hypoxic respiratory failure, 47 (44.8%) and coma, 37 (35.2%), the indications of which are similar to other studies elsewhere.^[2,8] Another study conducted elsewhere in Ethiopia showed respiratory failure as a leading indication for MV.^[17]

The median (IQR) duration of MV, which was 8 (5, 14) days, is relatively longer than the findings of published multinational studies.^[7] However, this was similar to a study conducted among critically ill patients in low-resource settings in India.^[18] The median (IQR) ICU length of stay was 10 (7,18) days, which is longer than the multinational study done by Esteban et al.^[7] where the median was 7 days. This difference might be related to multiple factors. First, lack of uniformity related to the weaning protocols physicians employ. Second, this is an open ICU setting where all credentialed physicians at ACSH can admit to the ICU. Third, patients get the intubation by the trained internist or anesthesia on duty whoever is available at the admission time and direct laryngoscopy is the method used for intubation. Fourth, there is no ICU protocol developed for analgosedation and physicians use the available medications based on their experience. Fifth, there is no respiratory physiotherapist, and hence, chest physiotherapy is performed by the ICU nurses and physicians themselves. These aforementioned factors are a plausible explanation for the longer duration of MV in the study setting. Tracheostomy was performed in 34 (32.4%) of the patients starting as early as day 1 and as late as day 25 of invasive MV. The median (IQR) duration of MV for tracheostomized patients was 15.5 (11–28). The high number of tracheostomy use is likely because of the need for prolonged intubation in patients with head injury and polytrauma which accounted for about 30% of the patients in this ICU.

The requirement for prolonged MV in this hospital was 11.4% which was consistent with a published report which showed an average of 10% (varying from 4% to 13%) of all mechanically ventilated patients.^[19] Age above 60 years was significantly associated with MV-related mortality which is congruent to the published study from a low-resource setting and high-income countries which have found that age has an independent effect on the outcome of patients treated with MV after ICU admission.^[7,20-23] Although chronological age is not a barrier to intensive care treatment and MV,^[24] older age is a predictor of poor survival most probably related to the limited physiological reserves of people of this age group. Moreover, the incidence of acute respiratory failure increases markedly with age and is especially high among persons >65 years of age and contributes to one-third of hospital mortality.^[25]

This study revealed the reintubation rate to be 8.5% in extubated patients. The rate of unplanned extubation was 16% which is almost comparable to a study from another similar setting which reported a rate of 20%.^[19] A multinational study in 2002 by Esteban et al. also reported that 12.2% required reintubation in the first 48 h.^[7]

The MV-related complications including AKI, liver failure, and pneumothorax were comparable to the multinational study done by Esteban et al. in 2002.^[7] However, the VAP rate which was 27.6% in this study was higher than the above-mentioned multinational study which showed a VAP development of 9.8%. This is likely due to the absence of VAP infection prevention protocols in our setup.

VAP, followed by catheter-associated urinary tract infection (CAUTI), was the leading source of infection among the patients who were under invasive MV; patients who developed septic shock had a significant risk of death. This is in line with the study by Esteban et al. where septic shock was associated with a significant risk of death.^[7] Similarly, a prospective study of medically ill patients in another low-resource setting showed septic shock as an independent factor associated with a high risk of mortality related to invasive MV.^[19] In addition, a study from high-income settings showed that older age and sepsis are independent predictors of hospital death among patients admitted to medical ICU.^[26] Employing cost-effective and evidence-based interventions as part of a “Ventilator bundle” including elevation of the patient’s head of the bed to 30–45° and daily oral care (with a toothbrush) are known to reduce the incidence of VAP in ICU.^[27-29] In addition, implementing targeted strategies for preventing CAUTI such as limiting the use and duration of urinary catheters, using an aseptic technique for catheter insertion, and adhering to proper catheter care should be endorsed in ICU to lower the incidence of sepsis and septic shock after intubation.^[30]

In the present study, patients who received invasive MV for more than 12 h had 28.6% mortality rate. This rate is lower than a study in South Ethiopia which revealed a mortality of 46.8%.^[11] A study of unselected patients in critically ill patients who required invasive MV in another low-resource setting showed a mortality rate of 37%.^[19] In limited resource settings, the mortality rate of invasive MV usage is higher and ranges from 36% to 72%.^[31-33]

The mortality rate in this study is close to the global trends.^[7] The mortality rate in this study is lower than in low-income and some middle-income countries. A study in India revealed a 71.5% mortality rate in mechanically ventilated patients.^[34] The lower mortality among the mechanically ventilated patients in our setting might be attributed to low associated morbidities similar to a study by Feng et al. Advanced patient age was significantly associated with high mortality in patients who received invasive MV.^[35]

CONCLUSION

MV was one of the main reasons patients get admitted to the ICU. A third of patients admitted to ICU required invasive MV. Hypoxic respiratory failure and coma were the two most common indications for invasive MV. The mortality rate among patients under MV in this study was comparatively lower than in most resource-limited settings. Age above 60 years and septic shock development after intubation were independent determinants for MV-related mortality. The finding of this study may help in the decision-making process regarding MV for older people and the need for standard MV protocols including adherence to a “ventilator bundle” to prevent complications after intubation.

DECLARATIONS