Evaluation of a rib fracture management pathway in an Australian tertiary trauma hospital

Abstract

Objective

Rib fractures are a common cause of hospitalisation in the adult trauma population and are associated with significant morbidity and mortality. This study aimed to assess the efficacy of a bundle of care known as the ‘rib fracture pathway’ in improving patient-centred outcomes and health economic outcomes in an Australian tertiary trauma hospital.

Methods

This single-centre retrospective cohort study analysed prospectively collected pain registry data from 2004 to 2022, encompassing the period before and after the implementation of the rib fracture pathway.

Results

The implementation of a rib fracture pathway was not associated with a reduction in patient reported pain scores at rest or on movement. Post-implementation, patients were more likely to receive a regional nerve block (56.7% vs. 10.4%, p < 0.001). Despite this, length of hospital stay was increased post-implementation (8.9 vs. 8.1 days, p = 0.01), and duration of Acute Pain Service follow-up increased (3.8 vs. 3.0 days, p < 0.001). The lengthier hospital stay persisted in patients with >2 rib fractures (8 vs. 7 days, p = 0.01).

Conclusions

This study demonstrates that the implementation of a rib fracture pathway was not associated with clear improvements in patient-centred outcomes and was associated with adverse health economic outcomes, including increased length of hospital stay.

Background

Rib fractures occur in ≥10% of all major trauma patients and are a major global cause of morbidity and mortality associated with trauma, specifically thoracic trauma. ¹ A significant cause of rib fracture–related morbidity and mortality are pulmonary complications, including respiratory failure, pulmonary embolism, pneumonia, atelectasis, pulmonary contusions, pneumothorax, haemothorax and haemo-pneumothorax.^1,2 The development of these complications can be attributed to factors, including impaired gas exchange from lung parenchymal or altered respiratory mechanisms, reduced pulmonary secretion from pain-related hypoventilation or inability to cough and decreased mobility in the setting of trauma and significant pain. Between 40% and 50% of thoracic trauma patients with rib fractures require admission to an intensive care unit (ICU) for management of their injuries or complications associated with rib fractures.^1,2 Multi-modal analgesic techniques are employed to address pain-related complications. This involves oral non-opioid analgesia, oral opioid analgesia, intravenous opioids and regional analgesia techniques. ³ Regional analgesia techniques include erector spinae plane block (ESPB), intercostal nerve block (ICNB), serratus anterior plane block (SAPB), thoracic epidural analgesia (TEA), pectoral nerve block type II (PECS-2) and thoracic paravertebral block (TPVB).^4,5

In 2019, our hospital implemented a ‘bundle of care model’ known as the rib fracture pathway with the goal of optimising analgesia and reducing complications associated with rib fractures. The differences in key components of the rib fracture pathway are presented in Table 1. The main differences were encouragement of early Acute Pain Service (APS) referral and a recommendation to consider a regional nerve catheter as a primary analgesia technique instead of a rescue technique.

Table 1.

Rib fracture pathway differences.

	Pre-implementation	Post-implementation
Timing of APS referral	If admitted and inadequate analgesia with maximal oral opioids	At presentation to the emergency department
Referral source	In-patient team under which the patient was admitted	Emergency physician first assessing patient at presentation
Timing of regional nerve block	If inadequate analgesia with a PCA	Strongly recommended to consider as first-line management
Single-shot block or nerve catheter	No recommendation	Recommendation to consider catheter technique in all patients requiring regional analgesia

PCA: patient-controlled analgesia; APS: acute pain service.

The APS is a 24 h a day/7 days a week consultation service staffed by an anaesthesia consultant during working hours and an anaesthesia registrar after office hours. Key components of this pathway were early referral of all rib fracture patients to the anaesthesia-led APS at the time of presentation to the emergency department, consideration of ESPB catheters at the time of referral and anaesthetist-led multi-modal analgesia prescribing. Prior to the implementation of this pathway, no formalised pathway for rib fracture pain management existed, and patients were referred to the APS at the discretion of the admitting physician after maximisation of oral analgesia options.

First described in 2016, the ESPB involves ultrasound-guided injection of long-acting local anaesthetic in the interfacial plane between the vertebral transverse process tips and erector spinae muscles.^6,7 The local anaesthetic can be injected as a single-shot or via inserted catheters. The ESPB has demonstrated a favourable safety profile in a previous study involving 224 patients who underwent ESPB catheter insertion, with no immediate complications such as hypotension, hypoxia, local anaesthetic toxicity or pneumothorax. ⁸

Since its introduction, there has been significant interest in employing the ESPB as part of rib fracture management, with many centres publishing their results.^8–12 Studies have demonstrated that use of the ESPB in patients with rib fractures leads to decreased pain scores; however, no significant decrease was observed the in overall opioid consumption.^9,11,12 Incentive spirometry may offer prognostic value in patients with rib fractures, with values reflecting respiratory function. ¹³ ESPB use has been associated with an increase in incentive spirometry volumes in patients with rib fractures.^9,11 ESP catheter insertion >48 h after admission is associated with a higher risk of respiratory complications including pneumonia, pulmonary embolism and respiratory failure. ¹⁰

This study aimed to compare patient-centred outcomes before and after the implementation of the rib fracture pathway.

Methods

We conducted a pragmatic, single-centre retrospective cohort study using the Flinders Medical Centre (FMC) APS registry database (2004–2022). This database contains prospectively collected data on all patients referred to the APS. Patients are typically managed by the APS for 5 days; therefore, we limited the duration of data collection to this period. We included all patients in this period with complete database records available. The local governing Human Research Ethics Committee granted approval for this registry analysis (SALHN/172.22) and this research was conducted in line with the Declaration of Helsinki.

Baseline demographic data on age, sex, mechanism of injury, number of rib fractures and unilateral or bilateral rib fractures were collected from all patients. The primary outcomes of interest were patient-reported pain outcomes and analgesia technique performed. Secondary outcomes of interest were number of APS reviews, duration of hospital admission, time to mobilisation and analgesia-related adverse effects.

Statistical analyses

The analyses were performed using Stata Version 18.0 (StataCorp; Texas, USA). Continuous variables were expressed as mean ± SD, whereas categorical variables were expressed as counts (percentages). Trendlines were used to describe outcomes of interest, where appropriate. Subgroup analysis was conducted with patients grouped based on number of rib fractures, presence of unilateral or bilateral rib fractures and presence of a regional nerve block technique. Outcomes were adjusted for age, sex and multi-trauma status.

Results

We enrolled a total of 367 consecutive patients in the analysis, including 164 prior to the implementation of a rib fracture pathway and 203 patients after the implementation of rib fracture pathway (Table 2). There were no significant differences in the proportion of patients with a multi-system injury (p = 0.78) or in terms of the number of rib fractures (p = 0.11). We analysed days 1–5 after hospital admission, wherein day 1 represented the day of arrival to the hospital.

Table 2.

Demographic and treatment data.

	Group 1: pre-pathway (N = 164)	Group 2: post-pathway (N = 203)	p-value
Age, years	53.6 ± 18.2	64.8 ± 16.2	<0.001
Sex			0.91
Female	55/164 (33.5%)	67/203 (33.0%)
Male	109/164 (66.5%)	136/203 (67.0%)
Mechanism of injury			<0.001
Road traffic accident	65/164 (39.6%)	53/203 (26.1%)
Fall	78/164 (47.6%)	137/203 (67.5%)
Other	21/164 (12.8%)	13/203 (6.4%)
Multi-system injury	42/160 (26.3%)	56/203 (27.6%)	0.78
Number of ribs involved	4.6 ± 2.8	5.1 ± 3.0	0.11
Bilaterality			0.78
Unilateral	137/160 (85.6%)	170/201 (84.6%)
Bilateral	23/160 (14.4%)	31/201 (15.4%)
Block provided	17/164 (10.4%)	115/164 (56.7%)	<0.001
Erector spinae block	2/17	10/115
Erector spinae catheter	11/17	100/115
Other (serratus anterior plane, paravertebral, epidural)	4/17	5/115
Non-oral analgesia
PCA	143/164 (87.2%)	130/203 (64.0%)	<0.001
Infusion	19/164 (11.6%)	35/203 (17.2%)	0.13
Other	10/164 (6.1%)	10/203 (4.9%)	0.62
Days reviewed, days	3.0 ± 1.8	3.8 ± 2.1	<0.001

PCA: patient-controlled analgesia.

The post-implementation outcomes are presented in Table 3. Patients were more likely to receive a regional nerve block (56.7% vs. 10.4%, p < 0.001) and less likely to be provided a patient-controlled opioid analgesia delivery system (64.0% vs. 87.2%, p < 0.001). Post-implementation, patients in the rib fracture pathway were reviewed for longer than those in the pre-implementation group (3.8 vs. 3.0 days, p < 0.001).

Table 3.

Patient outcomes after implementation of the rib fracture pathway.

Outcome	Group 1: pre-pathway	Group 2: post-pathway	Mean difference	p-value	Adjusted coefficient	Adjusted p-value
Length of stay, days	8.1 ± 7.6	8.9 ± 6.7	−0.9	0.009	0.51	0.46
Time to mobilisation, days	4.2 ± 2.1	3.3 ± 2.1	0.9	<0.001	−1.11	<0.001
Day 1 sedation score	0.3 ± 0.6	0.5 ± 0.6	−0.2	<0.001	0.23	<0.001
Day 1 pruritus score	0.1 ± 0.4	0.0 ± 0.1	0.1	0.01	−0.05	0.10
Day 1 nausea and vomiting score	0.4 ± 0.8	0.2 ± 0.6	0.1	0.13	−0.05	0.48

As depicted in Figure 1, post-implementation of a rib fracture pathway, resting pain and movement pain score remained unchanged from days 1 to 5. Post-implementation, the length of hospital stay was increased in the rib fracture pathway group (8.9 vs. 8.1 days, p = 0.01). Patient sedation scores were higher after the implementation of the rib fracture pathway (0.5 vs. 0.3, p < 0.001), whereas the incidences of pruritus and nausea remained unchanged. Time to mobilisation was shorter following the implementation of the rib fracture pathway (3.3 vs. 4.2 days, p < 0.001).

Figure 1.

Pain score on movement and at rest, pre- and post-pathway implementation.

Subgroup analyses were conducted. Patients were grouped based on the number of rib fractures, presence of unilateral or bilateral rib fractures and presence of a regional nerve block technique. Outcomes were adjusted for age, sex and multi-trauma status. Among patients with <2 unilateral rib fractures, those who received a regional nerve block had a longer hospital stay than those without a nerve block (7 vs. 5 days, p < 0.001). All other subgroup analyses did not reach statistical significance.

Discussion

The present findings demonstrated that the implementation of a rib fracture pathway model of care was associated with an increase in the number of erector spinae catheters inserted. A reduction in time to mobilisation was observed after implementation of the pathway. A causal relationship cannot be confirmed because data on allied health service utilisation were not available. A reduction in patient-controlled analgesia (PCA) prescription of opioid analgesia was observed; however, no data on post-discharge opioid prescription were available.

The increased duration of follow-up by the APS service may reflect improved continuity of care, particularly considering that previous literature describes peak pain trajectories occurring in rib fracture patients between days 2 and 3. ¹⁴ The rib fracture pathway was associated with an increased duration of hospital stay. This is consistent with the findings reported by Fitzgerald et al. who demonstrated similar patient outcomes for a multi-modal analgesia versus erector spinae nerve catheters in patients with rib fractures. ¹²

Potential confounding factors in our study that need to be acknowledged include an older and potentially frailer population in the post-implementation cohort (64.8 vs. 53.6 years, p < 0.001), in whom a fall was more likely to be the mechanism of injury (p < 0.001). Many patients who received a nerve block in our study population had ≤2 unilateral rib fractures (50%, 185/367), comprising a cohort who derive minimal benefit from a nerve block technique. To better identify patients who may benefit from a regional nerve catheter technique, we recommend the consideration of a single-shot technique which may provide up to 23–45 h of analgesia. ¹⁵

As the ESPB was only introduced in 2016, the early study period after the implementation of the rib fracture pathway in 2019 may have been associated with novices performing the block, lower efficacy and potentially poor patient selection in patients who may have been discharged home in the absence of a regional nerve catheter. Although not prescribed within the care pathway, the ESPB became the predominant regional block used in rib fractures.

Certain study limitations must be addressed. This was a retrospective cohort study based on a prospectively entered database; therefore, outcomes that may have been useful such as spirometry values, Injury Severity Score, Abbreviated Injury Scale, frequency of pulmonary complications and frequency of ICU admission were not collected. Given the absence of cohort matching and the fact that we only included patients referred to the APS, there is a potential for selection bias. Our study analysed data from the 5-day period during which the patients were managed by the APS; longer-term data beyond hospital discharge such as the incidence of chronic pain were not assessed.

Conclusion

The implementation of a rib fracture pathway model of care with early anaesthetic referral and consideration of placement of erector spinae catheters is associated with reduced opioid consumption and earlier mobilisation. These findings were not associated with reduced pain scores, reduced analgesic adverse effects or reduced hospital length of stay. A prospective study in this area is needed to further define the role of erector spinae catheters in rib fracture patients.