Tracheostomy-related indications, early complications and their predictors among patients in low resource settings: a prospective cohort study in the pre-COVID-19 era

Multiple indications for tracheostomy were noted in 69% of patients. The most common indications were; pulmonary toilet (58%), anticipated prolonged intubation (42%), upper airway obstruction (36%) and airway protection (28%). There were no significant disparities in all indications across hospitals except for airway protection which was more commonly encountered in patients at MNRH (40%) as compared MRRH (16%), p = 0.008 Table 2.

Table 3 shows that upper-airway obstruction was the commonest indication among males (93.7%) while airway protection was the commonest among females (62.5%) at MRRH, and this difference was statistically significant, p < 0.05. There were also no major disparities in indications of tracheostomy between adult and child patients in MRRH. Overall, at MNRH, no significant disparities were noted in indications for tracheostomy across gender and age categories.

A total of 76 complication events (38 in MRRH and 38 in MNRH) occurred among the 53 patients. Thirty-five patients developed one complication each while 18 patients developed multiple complications of whom 14 developed 2 complications and 4 developed more than two complications each. The commonest complications were; tube obstruction (52.6%), inadvertent decannulation (17.1%) and bleeding (11.8%) Table 4.

Table 5 shows the results of univariate and multivariate analysis for factors associated with tracheostomy related complications.

In univariate analysis, the statistically significant factors were; Oral feeding post-operatively, assisted post-operative ventilation, having an indication of anticipated prolonged intubation or upper airway obstruction, use of Bjork flap tracheal incision and peri-operative antibiotic use. In addition to these factors, admission diagnosis, age, gender, and the site for surgery were included in the final model and adjusted for.

In multivariate analysis, the only factors with a significant independent association with early tracheostomy-related complications were; being younger than 18 years, having an indication for tracheostomy of anticipated prolonged intubation, and having either a Bjork flap or a vertical tracheal incision.

Patients having anticipated prolonged intubation as the indication for tracheostomy was associated with a 1.8 times risk of developing early complications compared to patients with pulmonary toilet as their indication (RR = 1.8, 95%CI: 1.19 – 2.76, p = 0.005). Having a Bjork flap tracheal incision was associated with a 1.6 times risk of developing early complications (RR = 1.6, 95%CI: 1.09 – 2.43, p = 0.016) while those with vertical incision had a 1.5 times risk compared to those that received a T-incision (RR = 1.53, 95%CI: 1.02 – 2.27, p = 0.037). Being younger than 18 years was associated with a 1.2 times risk of early complications as compared to being 18 years and above (RR = 1.22, 95%CI2: 1.00 – 1.47, p = 0.048).

In this study, we observed that a considerable proportion (69%) of patients had more than one tracheostomy indication. This finding was probably because most (54%) of study participants were very ill ICU and HDU patients who are likely to have multiple challenges for example; reduced consciousness hence unable to protect their airways and clear airway secretions yet at the same time require prolonged intubation, all of which are recognized tracheostomy indications. This study found a comparable distribution of indications at the two study sites probably because of the similarity in patients’ sociodemographic characteristics as shown in Table 1, or disease epidemiology and risk for trauma given that they are both urban-based hospitals. We also found pulmonary toilet as the commonest indication which is at variance with what was previously reported in various African studies that found upper airway obstruction as the commonest indication [6, 19‐21] while others reported anticipated prolonged intubation as the commonest at 55.2% and 95% in Rwanda and India respectively [22, 23]. The discrepancy may have been because comparison studies that found upper airway obstruction as commonest differed from ours regarding to admission diagnoses. They reported significant contributions from aero-digestive infections and impacted airway foreign bodies among children, and aerodigestive trauma and tumors especially among their adult patients all of which contributed to the increased incidence of upper air-way obstruction. Our study also had few pediatric patients (16%) and with no patients with aero-digestive infections or airway foreign bodies. Overall, the commonest form of trauma we found was traumatic brain injury rather than aerodigestive trauma reported in other studies. In the same vein, the Indian study had 59% and 21.3% of their patients admitted due to severe organophosphate poisoning and snake bites respectively while in Rwanda, all their patients were recruited from ICU and had history of severe trauma, all of whom were likely to require prolonged periods of intubation for airway support. The present study however did not find similar indications and the trauma severity was not assessed.

The 53% incidence of early tracheostomy-related complications documented in this study, although in alignment with the global estimated range of 6 to 66%, is higher than the 21.5% reported in Tanzania [7]. Similarly, this incidence is higher than what has been reported in previous studies from comparable settings such as Nigeria where this rate ranged between 10.3% and 21% [6, 20] and India (29.8%) [24]. Lower complication rates (15%) have been documented in high income settings such as Finland [25]. Notably most of these studies were retrospective and considered all post-procedure complications and not only early complications. The high incidence in our study could be attributed to the cadre of surgeons performing the procedure in our case who were mainly residents in training unlike similar studies where mainly specialist otolaryngologists with arguably better skills and longer experience performed the procedures [25]. The observational nature of this study too could have triggered an increased intentional surveillance for complications resulting in the documentation of even more subtle episodes of tube obstruction hence providing a higher incidence as also seen in Kenya [14]. The quality of care given to patients could also have contributed to the high incidence of complications in the current study. The effectiveness of the five drivers of tracheostomy care improvement including; use of multidisciplinary tracheostomy care teams, standardized tracheostomy care protocols or pathways, staff education, patient and family involvement, and collection of patient-level data [4, 26] as recommended by the global tracheostomy collaborative was recently demonstrated in UK [27] but in the current study setting, only staff education, and patient and family involvement (2 of 5) are being implemented.

Our study reported tracheostomy tube obstruction as the commonest early complication (52.6%) which agrees with another study in similar settings that reported it at 80.3% in Kenya [15]. Our finding could be due to the fact that majority (72%) of tubes used had no disposable internal cannula in addition to absence of heat and moisture exchangers. The internal cannula is useful in trapping mucus secretions, which prevents clogging of the larger tube. It also makes it easy for patients and their attendants to participate in tube care by removing, cleaning and replacing the cannula on a regular basis. On the other hand, a heat and moisture exchanger is a filter fitted onto the tracheostomy tube to keep the airway humidified. This helps to thin out secretions, making them easy to either expectorate or suction out. In addition, as similarly highlighted by the Nyansikera and Kirui study, low staffing could also have made it harder to achieve the minimum of 3 times per day tracheostomy tube suctioning as recommended [28] to prevent this complication. In the absence of these vital resources, training of health workers and patient attendants on the proper procedure for tube suctioning can greatly reduce the incidence of tube obstruction. Life-threatening complications like tracheo-innominate fistula, pneumothorax and pneumomediastinum were not reported in this study and no mortality occurred as a result of tracheostomy.

Bearing in mind tracheostomy tube obstruction as the commonest complication in this study, our finding that anticipated prolonged intubation as an indication was associated with increased risk of early complications compared to pulmonary toilet may be because patients who were operated for this indication were more likely to have had a significantly severe illness. Such patients would still be too sick to self-care for their tracheostomy tubes even in the post-procedure period and this may be compounded by their inability to communicate a need to be suctioned or to have the tube cleaned or changed in addition to a higher possibility of a poor cough reflex. All these may have increased chances of retention of copious airway secretions hence a higher risk of tube obstruction. Such patients are also more likely to require assisted bed turning and bathing compared to more stable patients and this increases chances of inadvertent tube decannulation, which was in fact the second most common complication (17.1%) in this study.

Our finding that a patient being younger than 18 years was associated with increased risk of early complications was not surprising since this association had previously been reported by a study in a similar setting that found a higher complication rate among children below 10 years as compared to older patients [7]. This is in agreement with our study in which 10 out of the 16 children enrolled were below 10 years of age. This age group could be more prone to complications because they require smaller caliber tracheostomy tubes which are more prone to obstruction in addition to their anatomical features such as a shorter neck, more pliable laryngeal structures and more prominent subcutaneous fat. Pediatric tracheostomy requires procedural modifications if complications are to be minimized, for example, neck hyperextension may pull mediastinal structures in to the neck thus increasing chances of damage to lung apices and resultant emphysema, pneumothorax and pneumomediastinum. Also, children are less able to independently care for their tracheostomy sites and are still less likely to communicate the need to be suctioned which increases chances of tube obstruction as compared to adults.

The Bjork flap is an inferiorly based tracheal flap through the 2^nd, 3^rd, and 4^th tracheal rings which is fixed to the skin to stabilize the tracheal lumen. Although it has a risk for tracheal stenosis, it has advantages over traditional incisional and excisional window procedures including; reduced risk of false cannulation especially during emergency recannulation following accidental tube dislodgement, early stomal maturation and ease of stomal care by assistants and family members [29‐31]. These make it the preferred tracheal incision in our setting for patients who require tracheostomy for longer durations such as those with head and neck tumors. However, its indications may vary, as it was preferred for patients with prolonged mechanical ventilation and elevated body mass index while window procedures were used in head and neck cancer patients in USA [32].

Our finding that Bjork flap and vertical tracheal incisions were associated with increased risk of early complications may have been due to other factors surrounding their indication for tracheostomy. These two tracheal incisions are in themselves indicated in patients with an already increased risk for tracheostomy-related complications. For example, the Bjork flap is preferred for patients with head and neck cancer who already have increased risk for complications such as aspiration and tube displacement. The vertical incision is preferred for emergency tracheostomy and for children because it is faster and poses a low risk of severing paratracheal structures. However, in emergency situations, the risk complications such as bleeding, stomal site infection and surgical emphysema are increased [33, 34]. It is important to note that in the current study, all Bjork flaps were performed in head and neck cancer patients and all vertical tracheal incisions were performed in emergency procedures (43% of all procedures).

Despite earlier literature from a high income setting reporting up to 73% patients to have made tracheostomy-related post-discharge emergency room visits [35], it is still unknown as to how tracheostomy patients in our setting transition from hospital care to community care and how they fair post-discharge. Considering the high in-hospital complication rate in the current study, giving extra attention to their discharge preparedness and community integration would contribute greatly to their tracheostomy care while in the community.

The strength of our study is that it gives information on tracheostomy-related complications in low resource settings. The exclusion of patients with a known underlying risk of bleeding as per our exclusion criteria could have resulted in a possible under-estimation of the incidence of bleeding as a complication and the overall complication rate in the study population. However, we had no patient who was excluded based on this criterion, hence eliminating the impact of this anticipated limitation. The small sample size may have limited our ability to establish true associations between complications and the risk factors identified in addition to the small number of pediatric patients in this study which may affect the generalizability of our study results to the pediatric age group.