A total of 1224 cases that met criteria were included in the analysis. Of these, 40 (3.27%) were cancelled following the transfer team's arrival at the patient side and/or attempted preparation for transfer (Table 1). Amongst the completed cases, the majority were male [n=715 (60.39%)], and within the 40-59 [n=328 (27.7%)] and 20-39 [n=299 (25.25%)] age groups. Transfers were generally conducted on either a Monday [n=200 (17.26)] or Sunday [n=200 (16.92)] and between the hours of 07:00 – 15:00 [n=545 (46.03)]. Mean patient preparation time at the referring facility was approximately one hour [01:08 (IQR 00:38-01:18)] while the mean handover time at the referring facility was just under an hour [00:53 (IQR 00:29-00:57)]. The mean total mission time (dispatch to unit availability at receiving facility) was 02:46 (IQR 01:59-03:14), likely reflecting the relatively short distances of travel between facilities. In terms of crew composition, a Critical Care Paramedic was present on 99% (n=1166) of transfers and a doctor on 22.3% (n=264) of transfers.
Table 1
Transfer and demographic data
Characteristic | n | (%) |
Total | 1224 | |
Status | | |
Completed | 1184 | (96.73) |
Cancelled | 40 | (3.27) |
Completed cases only | | |
Mean time at referring facility (hh:mm) | 01:08 (IQR 00:38-01:18) |
Mean handover time (hh:mm) | 00:53 (IQR 00:29-00:57) |
Mean total mission time (hh:mm) | 02:46 (IQR 01:59-03:14) |
Hour of dispatch | | |
07:00-15:00 | 545 | (46.03) |
16:00-23:00 | 466 | (39.36) |
00:00-06:00 | 173 | (14.61) |
Day of dispatch | | |
Sunday | 200 | (16.92) |
Monday | 204 | (17.26) |
Tuesday | 182 | (15.40) |
Wednesday | 156 | (13.20) |
Thursday | 188 | (15.91) |
Friday | 119 | (10.07) |
Saturday | 133 | (11.25) |
Gender | | |
Male | 715 | (60.39) |
Female | 301 | (25.42) |
Not documented | 168 | (14.19) |
Age Category | | |
0 - 19 | 98 | (8.28) |
20 - 39 | 299 | (25.25) |
40 - 59 | 328 | (27.7) |
60 - 79 | 277 | (23.4) |
≥ 80 | 65 | (5.49) |
Not documented | 117 | (9.88) |
Case Category | | |
Environmental | 4 | (0.34) |
Medical | 1069 | (90.29) |
Surgical | 3 | (0.25) |
Trauma | 74 | (6.25) |
Not documented | 34 | (2.87) |
Crew Type | | |
Ambulance Paramedic | 1147 | (96.88) |
Critical Care Paramedic | 1166 | (98.48) |
Doctor | 264 | (22.3) |
Nurse/Respiratory Therapist | 18 | (1.52) |
Despite the clinical complexity of many patients transferred, a primary pathology was documented for recording purposes and represented the general focus for the patient's management. Amongst the cases transferred by the service, those with a primary respiratory/pulmonary pathology were the most common [n=232 (19.59)], followed by patients with an underlying cardiovascular [n=219 (18.5)] and those with a septic [n=177 (14.95) focus (Table 2). Risk scores and per-patient activity echoed the complexity of the cases transferred, with the majority of patients scored to be moderate to severe in nature (5-12) (Table 2). The highest proportion of critical patients were those with a cardiovascular primary pathology [n=19 (21.35)], followed by respiratory pathologies [n=17 (19.10) and septic patients [n=14 (15.73)]. From an intervention and patient management perspective, just over half of the patients analysed had a self-maintained airway [n=611 (51.6%)], followed by approximately a third of patients who had an endotracheal tube in situ for the transfer (n=435 [36.74)] (Table 3). Of the ventilated patients, the majority who had an initial Richmond Agitation and Sedation Scale (RASS) recorded on arrival scored <0 [n=282 (49.21%). For the non-ventilated patients, the majority were scored a Glasgow Coma Scale (GCS) of >12 [n=435 (79.23%)].
Table 2
Association between primary pathology and risk score
Characteristic | Total | 0 to 4 | 5 to 8 | 9 to 12 | 13 to 16 | p |
n | (%) | n | (%) | n | (%) | n | (%) | N | (%) |
Total | 1184 | 329 | (27.79) | 375 | (31.67) | 391 | (33.02) | 89 | (7.51) | |
Burns | 47 | (3.97) | 9 | (2.74) | 9 | (2.4) | 20 | (5.12) | 9 | (10.11) | <0.0001 |
Cardiovascular | 219 | (18.5) | 97 | (29.48) | 47 | (12.53) | 56 | (14.32) | 19 | (21.35) |
Chemical exp/Poisoning/Drug overdose | 13 | (1.1) | 4 | (1.22) | 2 | (2.25) | 2 | (0.53) | 5 | (1.28) |
Endocrine | 28 | (2.36) | 16 | (4.86) | 8 | (2.13) | 3 | (0.77) | 1 | (1.12) |
Gastrointestinal | 72 | (6.08) | 27 | (8.21) | 25 | (6.67) | 12 | (3.07) | 8 | (8.99) |
Genitourinary | 19 | (1.6) | 3 | (0.91) | 6 | (1.6) | 10 | (2.56) | 0 | |
Infectious/Parasitic | 14 | (1.18) | 4 | (1.22) | 2 | (0.53) | 7 | (1.79) | 1 | (1.12) |
Neurological | 152 | (12.84) | 26 | (7.9) | 38 | (10.13) | 79 | (20.2) | 9 | (10.11) |
Not documented | 34 | (2.87) | 27 | (8.21) | 1 | (0.27) | 6 | (1.53) | 0 | |
Oncological | 74 | (6.25) | 20 | (6.08) | 26 | (6.93) | 22 | (5.63) | 6 | (6.74) |
Other | 57 | (4.81) | 15 | (4.56) | 24 | (6.4) | 16 | (4.09) | 2 | (2.25) |
Renal | 14 | (1.18) | 5 | (1.52) | 4 | (1.07) | 5 | (1.28) | 0 | |
Respiratory/Pulmonary | 232 | (19.59) | 39 | (11.85) | 101 | (26.93) | 75 | (19.18) | 17 | (19.10) |
Sepsis/Infection | 177 | (14.95) | 22 | (6.69) | 73 | (19.47) | 68 | (17.39) | 14 | (15.73) |
Trauma - Neurological | 5 | (0.42) | 0 | | 3 | (0.8) | 2 | (0.51) | 0 | |
Trauma - Other | 22 | (1.86) | 11 | (3.34) | 6 | (1.6) | 4 | (1.02) | 1 | (1.12) |
Table 3
Primary interventions and medications
Characteristic | n | (%) |
Total | 1184 | |
Airway type | | |
ETT | 435 | (36.74) |
Self-maintained | 611 | (51.6) |
Tracheostomy tube | 138 | (11.66) |
Ventilation | | |
Invasive | 573 | (48.4) |
Non-invasive | 62 | (5.24) |
Nil | 549 | (46.37) |
Initial GCS in non-ventilated | | |
<8 | 19 | (3.46) |
8 to 12 | 51 | (9.29) |
>12 | 435 | (79.23) |
Not recorded | 44 | (8.01) |
Initial RASS for invasive ventilated | | |
1 to 4 | 20 | (3.49) |
0 | 112 | (19.55) |
-1 to -5 | 282 | (49.21) |
Not recorded | 159 | (27.75) |
Venous/Arterial access | | |
Arterial line | 309 | (26.1) |
Central Venous line | 388 | (32.77) |
Peripheral Venous line | 893 | (75.42) |
Number of Venous/Arterial access points | | |
0 | 194 | (16.39) |
1 | 589 | (49.75) |
2 | 202 | (17.06) |
3 | 199 | (16.81) |
Primary hypnotic agent used | | |
Dexmedetomidine | 33 | (12) |
Etomidate | 1 | (0.36) |
Ketamine | 6 | (2.18) |
Midazolam | 141 | (51.27) |
Propofol | 100 | (36.36) |
Primary analgesic used | | |
Fentanyl | 294 | (88.02) |
Morphine | 4 | (1.2) |
IV Paracetamol | 6 | (1.8) |
Remifentanyl | 30 | (8.98) |
Primary inotrope used | | |
Adrenaline | 5 | (2.23) |
Dobutamine | 2 | (0.89) |
Dopamine | 33 | (14.73) |
Noradrenaline | 163 | (72.77 |
Phenylephrine | 21 | (9.38) |
ETT – Endotracheal tube |
GCS – Glasgow Coma Scale |
RASS - Richmond Agitation and Sedation Scale |
IV - Intravenous |
There was considerable variation regarding arterial/venous access among patients transferred, with peripheral access the most common route found, present among 75% of patients transferred. Combinations of access routes were equally varied, with the arterial/central venous/peripheral venous combination the most common reported [n=181 (15.29%)], followed by the central venous/peripheral venous combination [n=93 (7.85%)] (Table 4). Similarly, there was considerable variation regarding the medications administered for transfer and routes of administration/vitals monitoring. Midazolam was the most common hypnotic administered [n=141 (51.27)], as was Fentanyl [n=294 (88.02)] amongst the analgesic medications administered, and Noradrenaline amongst the inotropes used [n=163 (72.77)] (Table 3). The most common combination amongst the three medication types was a hypnotic/analgesic combination [n=139 (11.74%)], followed by hypnotic/analgesic/inotrope combination [n=110 [9.29%)] (Table 4).
Table 4
Association between key case characteristics and airway status
Characteristic | Total | Self-maintained | Self-maintained - NIV | Trach tube | Endotracheal tube | P value |
N | (%) | N | (%) | N | (%) | N | (%) | N | (%) |
Total | 1184 | | 549 | | 62 | | 138 | | 435 | | |
Crew Type | | | | | | | | | | | |
Ambulance Paramedic | 1147 | (96.88) | 524 | (95.45) | 61 | (98.39) | 137 | (99.28) | 425 | (97.7) | 0.051 |
Critical Care Paramedic | 1166 | (98.48) | 531 | (96.72) | 62 | (100) | 138 | (100) | 435 | (100) | <0.0001 |
Doctor | 264 | (22.3) | 65 | (11.84) | 5 | (8.06) | 32 | (23.19) | 162 | (37.24) | <0.0001 |
Nurse/Respiratory Therapist | 18 | (1.52) | 1 | (0.18) | 0 | | 2 | (1.52) | 15 | (3.45) | <0.0001 |
Risk Score | | | | | | | | | | | |
0 to 4 | 329 | (27.79) | 308 | (56.1) | 14 | (22.58) | 0 | | 7 | (1.61) | <0.0001 |
5 to 8 | 375 | (31.67) | 225 | (40.98) | 41 | (66.13) | 63 | (45.65) | 46 | (10.57) |
9 to 12 | 391 | (33.02) | 16 | (2.91) | 7 | (11.29) | 72 | (52.17) | 296 | (68.05) |
13 to 16 | 89 | (7.52) | 0 | | 0 | | 3 | (2.17) | 86 | (19.77) |
Access type | | | | | | | | | | | |
No access | 194 | (16.39) | 71 | (12.93) | 17 | (27.42) | 66 | (47.83) | 40 | (9.20) | <0.0001 |
Single access point (any) | 622 | (52.53) | 364 | (66.30) | 36 | (58.06) | 57 | (41.30) | 165 | (37.93) |
Arterial + Central Venous | 93 | (7.85) | 44 | (8.01) | 3 | (4.84) | 7 | (5.07) | 39 | (8.97) |
Arterial + Peripheral Venous | 57 | (4.81) | 25 | (4.55) | 2 | (3.23) | 2 | (1.45) | 28 | (6.44) |
Central Venous + Peripheral Venous | 37 | (3.12) | 9 | (1.64) | 1 | (1.61) | 2 | (1.45) | 25 | (5.75) |
Arterial + Central Venous + Peripheral Venous | 181 | (15.29) | 36 | (6.56) | 3 | (4.84) | 4 | (2.90) | 138 | (31.72) |
Medication combinations | | | | | | | | | | | |
No Hypnotic/Analgesic/Inotrope | 740 | (62.50) | 468 | (85.25) | 52 | (83.87) | 125 | (90.58) | 95 | (21.84) | <0.0001 |
Single Hypnotic/Analgesic/Inotrope (any) | 162 | (13.68) | 79 | (14.39) | 5 | (8.06) | 8 | (5.80) | 70 | (16.09) |
Analgesic + Inotrope | 27 | (2.28) | 2 | (0.39) | 0 | | 2 | (1.45) | 23 | (5.29) |
Hypnotic + Analgesic | 6 | (0.51) | 0 | | 0 | | 1 | (0.72) | 5 | (1.15) |
Hypnotic + Inotrope | 139 | (11.74) | 0 | | 4 | (6.45) | 0 | | 135 | (31.03) |
Hypnotic + Analgesic + Inotrope | 110 | (9.29) | 0 | | 1 | (1.61) | 2 | (1.45) | 107 | (24.60) |
Table 5
Crude and adjusted prevalence ratios for intubation status and arteriovenous access; and medication combination
| N (%) | ETT/Trach Crude PR; 95% CI (p-value) | ETT/Trach Adjusted PR; 95% CI (p-value)* |
Access type | | | |
No access | 194 (16.39) | 1 | 1 |
Single access point (any) | 622 (52.53) | 0.65; 0.55 – 0.77 (< 0.0001) | 0.65; 0.54 – 0.79 (< 0.0001) |
Arterial + Central Venous | 93 (7.85) | 0.91; 0.71 – 1.15 (0.421) | 1.02; 0.79 – 1.31 (0.897 |
Arterial + Peripheral Venous | 57 (4.81) | 0.96; 0.73 – 1.27 (0.792) | 1.08; 0.80 – 1.47 (0.697) |
Central Venous + Peripheral Venous | 37 (3.12) | 1.34; 1.01 – 1.69 (0.016) | 1.44; 1.14 – 1.83 (0.003) |
Arterial + Central Venous + Peripheral Venous | 181 (15.29) | 1.44; 1.24 – 1.67 (< 0.0001) | 1.62; 1.36 – 1.93 (< 0.0001) |
Medication combinations | | | |
No Hypnotic/Analgesic/Inotrope | 740 (62.50) | 1 | 1 |
Single Hypnotic/Analgesic/Inotrope | 162 (13.68) | 1.62; 1.33 – 1.97 (< 0.0001) | 1.71; 1.37 – 2.13 (< 0.0001) |
Analgesic + Inotrope | 27 (2.28) | 3.11; 2.67 – 3.63 (< 0.0001) | 3.54; 2.94 – 4.27 (< 0.0001) |
Hypnotic + Analgesic | 6 (0.51) | 3.36; 3.01 – 3.76 (< 0.0001) | 3.43; 2.43 – 4.83 (< 0.0001) |
Hypnotic + Inotrope | 139 (11.74) | 3.27; 2.91 – 3.66 (< 0.0001) | 3.83; 3.32 – 4.41 (< 0.0001) |
Hypnotic + Analgesic + Inotrope | 110 (9.29) | 3.33; 2.98 – 3.73 (< 0.0001) | 3.74; 3.26 – 4.29 (< 0.0001) |
*Adjusted by age and gender |
Airway/Ventilation status was found to be a relatively good proxy indicator of both severity and activity. Endotracheally intubated patients had the highest proportion of severe and critical patients; patients transported with a Doctor; patients with multiple routes of arterial and/or venous access; and patients receiving any hypnotic, analgesic or inotrope, or a combination thereof (Table 4). After adjusting for age and gender, the most prevalent access types and medication combinations among intubated patients was the arterial/central venous/peripheral venous access combination [PR 1.62; 1.36–1.93 (<0.0001)] and the hypnotic/Inotrope combination [PR 3.83; 3.32–4.41 (<0.0001)], followed closely by hypnotic/analgesic/inotrope combination [PR 3.74; 3.26–4.29 (<0.0001)].