Assessment of Hypovolaemic Shock at Scene
Assessment of Hypovolaemic Shock at Scene
A total of 46 689 patients was retrieved from the TraumaRegister DGU® for analyses. Out of these patients, only 12 432 patients (26.5%) could be adequately classified according to PHTLS by matching the combination of all three parameters (HR, GCS and SBP). In contrast, 73.5% (n=34 446) of all trauma patients could not be allocated to one of the respective shock classes if the combination of all three vital signs was assessed (figure 1A). When blunt and penetrating trauma patients were analysed separately, no difference in the percentage of correctly classified patients according to PHTLS was observed (26.6% vs 28.3%). In patients with severe TBI (AIShead ≥3), the percentage of patients classified decreased to 12.2% (n=2396/19 569), whereas patients without TBI matched the criteria given by PHTLS in 36.7% (n=10 027/27 300). The vast majority of all patients (97.9%) were allocated to groups I and II, while groups III and IV were represented only marginally (figure 1B). Within the four groups, trauma mechanism or the presence of TBI had no influence on the distribution of patients.
(Enlarge Image)
Figure 1.
(A) Percentage of patients who could be either classified or not classified according to prehospital trauma life support (PHTLS) when a combination of all three parameters (heart rate, systolic blood pressure and Glasgow coma scale) was assessed. (B) Patient distribution into the respective classes I–IV of the PHTLS classification of hypovolaemic shock (in percentages). TBI, traumatic brain injury.
All trauma patients were classified by their HR at scene into the four PHTLS groups. Within the four groups, mean SBP dropped from 125 (±33) mm Hg in group I to 111 (±43) mm Hg in group IV (Table 2). Simultaneously, the median GCS decreased from 14 (9–15) in group I patients to 10 (3–15) in patients with a HR greater than 140 (group IV). In penetrating trauma patients, there was a more pronounced association between increased HR and the decline in SBP, but still less dramatic than postulated by PHTLS. If GCS values in patients with severe TBI were analysed, GCS declined from a median of 10 (4–14) in group I to a median of 5 (3–10) in group IV. Table 2B also summarises demographics and injury severities for all trauma patients when grouped by HR.
When patients were classified by their SBP at scene, the decline in SBP was not associated with significant alterations in HR (Table 3). In contrast to PHTLS, no subgroup displayed a relevant increase in HR (HR>100/min). On average, in normotensive patients (SBP≥110 mm Hg) a median GCS of 14 (11–15) was observed, whereas hypotensive patients (SBP<90 mm Hg) presented with a median GCS of 8 (3–14). In TBI patients, the median GCS declined from 11 (5–14) in group I to a median of 3 (3–8) in group IV. Simultaneously, the decline in SBP was associated with a higher mortality and injury severity (Table 3).
If patients were grouped by GCS at scene, an association between decreased GCS and a decline in SBP was noted; however, significant episodes of hypotension—as postulated by PHTLS—were not observed in any subgroup (Table 4). In patients with penetrating injuries, SBP values were slightly lower through groups I to IV. HR were comparable across all groups and no relevant tachycardia was detected in any subgroup. Declines in GCS were associated with a higher injury severity and mortality.
Results
Allocation of Patients Into the PHTLS Classes of Hypovolaemic Shock by a Combination of all Three Parameters (HR, SBP and GCS)
A total of 46 689 patients was retrieved from the TraumaRegister DGU® for analyses. Out of these patients, only 12 432 patients (26.5%) could be adequately classified according to PHTLS by matching the combination of all three parameters (HR, GCS and SBP). In contrast, 73.5% (n=34 446) of all trauma patients could not be allocated to one of the respective shock classes if the combination of all three vital signs was assessed (figure 1A). When blunt and penetrating trauma patients were analysed separately, no difference in the percentage of correctly classified patients according to PHTLS was observed (26.6% vs 28.3%). In patients with severe TBI (AIShead ≥3), the percentage of patients classified decreased to 12.2% (n=2396/19 569), whereas patients without TBI matched the criteria given by PHTLS in 36.7% (n=10 027/27 300). The vast majority of all patients (97.9%) were allocated to groups I and II, while groups III and IV were represented only marginally (figure 1B). Within the four groups, trauma mechanism or the presence of TBI had no influence on the distribution of patients.
(Enlarge Image)
Figure 1.
(A) Percentage of patients who could be either classified or not classified according to prehospital trauma life support (PHTLS) when a combination of all three parameters (heart rate, systolic blood pressure and Glasgow coma scale) was assessed. (B) Patient distribution into the respective classes I–IV of the PHTLS classification of hypovolaemic shock (in percentages). TBI, traumatic brain injury.
Patients Classified by HR
All trauma patients were classified by their HR at scene into the four PHTLS groups. Within the four groups, mean SBP dropped from 125 (±33) mm Hg in group I to 111 (±43) mm Hg in group IV (Table 2). Simultaneously, the median GCS decreased from 14 (9–15) in group I patients to 10 (3–15) in patients with a HR greater than 140 (group IV). In penetrating trauma patients, there was a more pronounced association between increased HR and the decline in SBP, but still less dramatic than postulated by PHTLS. If GCS values in patients with severe TBI were analysed, GCS declined from a median of 10 (4–14) in group I to a median of 5 (3–10) in group IV. Table 2B also summarises demographics and injury severities for all trauma patients when grouped by HR.
Patients Classified by SBP
When patients were classified by their SBP at scene, the decline in SBP was not associated with significant alterations in HR (Table 3). In contrast to PHTLS, no subgroup displayed a relevant increase in HR (HR>100/min). On average, in normotensive patients (SBP≥110 mm Hg) a median GCS of 14 (11–15) was observed, whereas hypotensive patients (SBP<90 mm Hg) presented with a median GCS of 8 (3–14). In TBI patients, the median GCS declined from 11 (5–14) in group I to a median of 3 (3–8) in group IV. Simultaneously, the decline in SBP was associated with a higher mortality and injury severity (Table 3).
Patients Classified by GCS
If patients were grouped by GCS at scene, an association between decreased GCS and a decline in SBP was noted; however, significant episodes of hypotension—as postulated by PHTLS—were not observed in any subgroup (Table 4). In patients with penetrating injuries, SBP values were slightly lower through groups I to IV. HR were comparable across all groups and no relevant tachycardia was detected in any subgroup. Declines in GCS were associated with a higher injury severity and mortality.