Utilization of mechanical ventilators in low resource Faculty: a cross sectional study


 Background

Few studies are available from Africa on the use of mechanical ventilation (MV) in the pediatric intensive care unit (PICU). Knowledge of the outcome of patients on MV is critical for better use of resources and clinical decision making. We aimed to see the outcome and pattern of patients treated in a pediatric intensive care unit in a teresery hospital, which is the first study to evaluate an Ethiopian PICU.
Methods

A cross-sectional study with retrospective data collection was employed. Data were abstracted from the patients’ medical records by trained health professionals. SPSS version 21 software was used for data entry and analysis. The reports were depicted descriptively using measures of central tendency, dispersion, and displayed through tables and graphs.
Results

There were 536 patients admitted during the study period. 202 (41.2%) incidence of mechanical ventilation (MV) rate 63.6% of the participants were males and 130 (59.1%) died. The most common indication for the initiation of MV was respiratory problems 46 (20.9%). we identified 30.59/1000 ventilator days developed complications.Ventilator-associated pneumonia accounted for 18.6% of the complications with 20.9/1000 ventilator days. Survival of medical cases was better than the surgical cases (including trauma); [AOR = 0.13, 95% CI(0.04–0.413)] and those who have MV for more than 3 days are 79% more likely to die than those of less than 3 days ventilated; (p = 0.003). Those who have multi-organ dysfunction syndrome die more likely than the other group of patients; [AOR = 0.181, 95% CI (0.08, 0.412)] and the patient who had high PIM II severity score had higher mortality rate; [AOR = 35, 95% CI (1.7, 11)].
Conclusions

In the current study, the mortality rate of mechanically ventilated pediatric patients was high. Severity score, multi-organ dysfunction syndrome, length of stay, and being a surgical patient increased the risk of mortality. Adequate education of PICU staff on the use of mechanical ventilator and prevention of complications as well as the use of severity score is necessary.


Background
Mechanical Ventilation (MV) is a life-supporting strategy used at the time of either impending or acute respiratory failure with the aims of improving gas exchange and decreasing work of breathing (1,2).
Given the high load of respiratory problems being the primary reason for admission to the intensive care unit in low resource countries (LRIC), there is a need for proper use of MV (3)(4)(5)(6)(7)(8).
There is a disparity of available resources like mechanical ventilators and trained health providers between the LRIC and high resource income countries (HRIC). Most ICUs have no adequate available resources in LRIC (3). The percentage of children receiving MV in PICUs ranges from 17-64% in developed countries where PICUs are a well-established discipline of medicine (2). There is a great scarcity of data from African countries regarding the use of MV in PICUs. The incidence of utilizing MV in children in Egypt was 32.8% (9). The study in Nepal showed that out of the 16 pediatric ICUs, 32% had only one functioning mechanical ventilator and another 38% had two ventilators, the other units had 3-6 ventilators (10).
Despite its important role, MV is associated with poor outcomes and might lead to complications like shock, ventilator-associated pneumonia (VAP), pulmonary hemorrhage, pneumothorax, atelectasis, and also side effects of medications (e.g. sedatives and analgesia) (2,11 ). Many studies in developing countries have revealed that the mortality rate ranges from 40-60% in mechanically ventilated children. A study in the PICU of Aga Khan University Hospital in Pakistan found that the mortality rate among mechanically ventilated patients was 30.5% and the complication rate was 9.4% (1). A report from Nepal revealed a 34.1% mortality rat6e (10).
The scarce resources in Ethiopia made physicians choose very di cult rationing bedside decisions because of a lack of resources like intensive care beds and mechanical ventilators (12). The information on patient characteristics and outcomes in patients requiring MV is critical for better use of resources and clinical decisions for the limited pediatric intensive care unit (PICU) (13,14). However, this information is not dealt with in our setting. Therefore, the present study aimed to assess the characteristics and outcomes of mechanically ventilated pediatric patients in Tikur Anbessa specialized referral hospital, Addis Ababa, Ethiopia.

Setting and Study Period
The study was conducted from September 2016 to February 2018 at Tikur Anbessa Specialized Hospital which is the largest referral and teaching hospital in Addis Ababa, the capital city of Ethiopia. The hospital used to manage children either in adult medical or surgical ICU. Starting from 2012 the rst two pediatric emergency and critical care physicians for a country established a separate four-bed ICU in 2012 which is the rst PICU in Ethiopia. These two physicians cover both emergency and intensive care units during the day and on-call during the night while the nights are covered by pediatric residents. Nurse to patients ratio is 1: 2. There is no respiratory therapist.
Each PICU bed has mechanical ventilation and equipped with a monitor along with end-tidal CO2 monitoring. This unit shares a portable X-ray machine with the adult ICU which is in the next door. We use Philip V200 mechanical ventilator for respiratory support in our PICU. Mechanical ventilation in all patients was initiated through an Endotracheal tube. The modes of MV mostly used were synchronized intermittent mandatory ventilation (SIMV) either volume (SIMV or pressure limited, or SIMV with pressure support (PS), assist control pressure-controlled ventilation AC/PCV assist control volume-controlled ventilation AC/VCV. The other parameters set depending on the patient's condition as FIO2, PEEP, PIP, and VT. Monitoring the subjects on MV was done with clinical examination but arterial blood gas not available PaO2 is estimated from the saturation of oxygen and PaCO2 with Entidal carbon dioxide monitor, and oxygen saturation was continuously recorded through a pulse oximeter. A chest X-ray was ordered on demand. Chest physiotherapy is done by a nurse and rarely with a physiotherapist. Subject weaning was initiated after improving clinical condition, criteria of extubation were, when the need of FIO2<0 .4 and depend on the clinical examination.
All children during mechanical ventilation were getting intermittent doses of diazepam and morphine (which mostly available in PO form ) as sedation and analgesia mostly. Thiopental and propofol are used rarely for status epilepticus cases and very rarely midazolam and fentanyl are rarely used as it is not available. Sometimes ketamine and Sedation of perfusion rarely continuous infusion is used because of the lack of infuser pumps. The neuromuscular blocking agent was never used.

Participants and Sampling Technique
All pediatric patients who were mechanically ventilated in the pediatric ICU of TASH for at least 24 hours during the study period were included whereas those patients with incomplete charts and lost charts were excluded from the study.

Study Design
Institutional based cross-sectional study design was employed by using a review of the patient's medical charts.

Data Collection Tools and Procedures
The instrument used to collect the data for this study was a structured data abstraction tool developed from the literature review. The tool has three parts: Socio-demographic characteristics of the participants, characteristics of mechanically ventilated patients, and patient outcome.

Data Analysis
Data were checked for completeness and coded manually and entered into SPSS version 21 for analysis.
Both descriptive and analytical statistical procedures were utilized. Descriptive statistics like percentage, mean, median, standard deviation, and interquartile range (IQR) were used for the presentation of characteristics of mechanically ventilated patients; and tables and graphs were also used for data presentation. Binary and multivariable logistic regression models were used with 95% CI and p-value less than 0.05 taken as signi cant.

Operational De nition
Ventilator-associated pneumonia was diagnosed in patients on MV for more than 48 hours with a new persistent in ltrate on chest radiograph and at least 3 of the following; fever, leucopenia or leukocytosis, increased sputum production, rales, cough or worsening gas exchange (8).

Ethical Consideration
The ethical clearance was obtained from Addis Ababa University, College of Health Sciences, Departments of Emergency Medicine and Pediatrics, and Child Health Research and publication Committee.
Additionally, the con dentiality of all the data was seriously respected by not mentioning patients' identi ers in the questioner and unauthorized individuals were not allowed to access the data which was collected by using a password-protected computer.

Results
There were 537 patients admitted to the PICU in two and a half years and 220 patients met the inclusion criteria. Most of the study subjects (39.1 %) were younger than 1 year and 63.6% of the participants were males ( Table 1)  The source for admission to PICU was from the pediatric emergency department (102; 46.4%), from the operation room (57; 25.9%), from inpatient units (47; 21.4%),and from another hospital (14; 6.4%).
Regarding the general indication of PICU admission, 160 (72.7%) were medical patients and 60 (23.7%) were surgical patients. From 149 (67.7%) of the children who were screened for HIV and 4 (1.8%) were positive. The most common indication for the initiation of mechanical ventilation was respiratory problems 46 (20.9%) and the mean weight in kilogram was 12.73±9.12 (mean±SD) and Glasgow Coma Scale (GCS) of patients at admission was <8 in 73 (33.2%).

Discussion
The COVID pandemic exposed the burden and need for a mechanical ventilator globally. This scarcity is much exaggerated in Africa where fewer than 2,000 working ventilators in public hospitals available across 41 African countries, compared with more than 170,000 in the U.S. Ten countries in Africa have no ventilator at all (14). There is scarce available data from African countries regarding the use of MV in the intensive care unit in particularly in pediatrics. Even if most data's from resource-limited setting are underreported; there are a high burden and mortality of respiratory failure in LRIC compared to HRIC, the provision of mechanical ventilators help save lives if implemented in a thoughtful fashion (14). This is the rst study in Ethiopia to look for characteristics and short-term outcomes of mechanically ventilated children as it is important to know how this scare resource being used.
There were 536 Patients admitted during the study period with 202 (41.2%) supported by mechanical ventilation. In a previous study in Gondar university ie the Northern part of Ethiopia 10% of pediatric ICU admissions required Mv (15) on the other hand children admitted to the general ICU of the university hospital southeastern part of Ethiopia (Jimma) it was 37% (16). Both these are lower than the current study. This could be Tikur Anbessa is last referral hospital in Ethiopia where more complicated cases and also e Gondar hospital used 1 ventilator and Jimma used shared the general ICU that might have a role also. Other studies reported a varying incidence of MV use in PICU: 30% in 16 United States PICUs (17); in Egypt of 32.8% (9), 34.6% in an Italian study (18), 50.7% in Pakistan (1) and 52% in Sri Lanka (19).
This study identi ed that respiratory (20.9%) was the most common indication for admission. A Prospective cohort Brazil and retrospective follow up study in Turkey and another multicenter study showed acute respiratory failure was a primary reason for MV 59.18%, and 72%, 64.8% respectively (4,20,21). However, our nding differs from a study done in a prospective observational study in Cairo in which the main indication for MV was neurologic cases 38.9% (9) and the discrepancy might be due to respiratory diseases like pneumonia that are common in Ethiopia and is one of the top causes of mortality in the country for children younger than 5 years of age (22).
This study found that SIMV was the most commonly used MVmode (80.0%). Similarly, the retrospective review in Pakistan (1) and prospective descriptive study in India (2), Egypt (9), Turkey (21), and Bangladesh (23) reported the commonest ventilator mode to be SIMV (21 ). Several published reports also found that SIMV the most commonly used mode of MV in multiple PICUs in the USA (17). The weaning method employed was CPAP alone 24.5% whereas the study of the group from Cairo showed that pressure support (PS) with CPAP was the preferred method of weaning in 74.7% of the cases (9). The  (18), Latin America (6), and in Cairo (9) respectively. This variation could be due to the variation in the reason for admission.
Though it is lower than the reported in Cairo (39.9%) and also 40% in Principi et al (24). This study showed VAP of 18.6% with 20.9/ 1000 ventilator days which is similar to Meligy et al where VAP had accounted for 20.19 per 1000 ventilation days (9). Higher values VAP also reported in (36.2%) India (2) and Egypt (31.8/1000) ventilator-days (24). The atelectasis occurred in 5% in this study which is similar to (4.6%) in Pakistan (1) and (4.4%) in Egypt (9).
Logistic regression analysis re ected, predictors of mortalities were the presence of MODS; higher severity score, surgical rather than medical cases (including trauma), and pronged duration of MV. Our MODS rate of 57.3% of the cases higher than studies done in (7.6%) India (2) and (41.3%) Egypt (9). The higher discrepancy in our study might be due to delayed admission to PICU, a limited early resuscitation practice in our setting which is a crucial method of preserving organs from failing. Prolonged MV more than 3 days were 79% more likely to die than those of less than 3 days ventilated; (p = 0.003). This is similar to the Pakistan study where prolonged mechanical ventilation (> 10days) is an important predictor of mortality (1). Similarly, those who are on MV died more in Italian study than those who are not MV (18).
Higher Severity score showed higher mortality in our study and which is similar to multiple other studies.
Surgical cases die more than the medical case because we included those severs traumatic injuries in this list. This study revealed that the mortality rate was 59.1% which is higher than in Czech Republic 3.5% (27), in Italy 6.7% (18), in sir Lanka 27.6% (19), in Pakistan 30.3%( 1), India 43.8%( 2) and in Egypt study (9) respectively. Also it is higher than from Faris et al from international study of 36 Picus of seven countries 15.6% (28), The report in developed countries ranged from 1.6-15% (4-7, 17, 18, 27). Sepsis (26.8%) and ARDS (13.6%) were among the common causes of mortality in our study Dahlem

Limitations Of The Study
Secondary data were used for this study; so that it was di cult in getting all the necessary data which are important for the study like anthropometry measurements. None of the patients had a blood gas analysis.

Conclusion
This study identi ed that the mortality rate of mechanically ventilated pediatric patients in Tikur Anbesa The datasets used and/ or analyzed during the current study are available from the corresponding author on resoanable request.

Competing Interest
We have no competing interest.

Funding statement
This work was funded by Addis Ababa University College of Health Science.
Authors' contribution TH: selected topic, help writing of the proposal , analyzed the data and wrote the manuscript, NT: wrote a draft of the proposal, collected data, and review the manuscript, WT: assisted in the design of critical review of the proposal and edited the nal manuscript .All authors read and approved the nal draft of the manuscript for publication.