Impact of nurse empowerment for early adrenaline administration for in-hospital cardiac arrest resuscitation: A pre-post intervention study

Table 1 Demographic and outcome data, n (%)¹

Parameter	All patients (n = 450)	Pre-intervention (n = 162)	Post intervention (n = 288)	P value
Demographics
Age, mean ± SD years	52.5 ± 16.1	53.3 ± 16.1	52.1 ± 16.1	0.44
Gender, male	284 (63.1)	103 (63.6)	181 (62.9)	0.92
Details of cardiac arrest
Initial arrest rhythm
Asystole	425 (94.4)	151 (93.2)	274 (95.1)	0.40
PEA	25 (5.6)	11 (6.8)	14 (4.9)
Witnessed arrest	445 (98.9)	159 (98.2)	286 (99.3)	0.36
Monitoring prior to arrest	416 (92.4)	149 (92)	267 (92.7)	0.85
Time to activate CART, median (IQR) minutes	2 (1, 5)	4 (1, 7)	2 (0, 3)	< 0.001
Time to CART arrival, median (IQR) minutes	5 (3, 8)	6.5 (4, 10)	4 (3, 6)	< 0.001
Time to CPR initiation, median (IQR) minutes	0 (0, 0)	0 (0, 0)	0 (0, 0)	0.52
Reversible cause identified	315 (70)	87 (53.7)	228 (79.2)	< 0.001

¹Indicates those who received the first dose of adrenaline within 2 minutes; data on time of adrenaline administration available only for 426 patients.

IQR: Interquartile range; ROSC: Return of spontaneous circulation; CPR: Cardiopulmonary resuscitation; CART: Cardiac arrest resuscitation team; PEA: Pulseless electrical activity.

Table 2 Details among patients who achieved return of spontaneous circulation, n (%)

Parameter	All patients (n = 260)	Pre-intervention (n = 92)	Post intervention (n = 168)	P value
Time to 1st adrenaline, median (IQR) minutes	2 (0, 4)	3 (0, 6)	1 (0, 2)	< 0.001
Timely adrenaline administration1	166 (68.6)	40 (48.8)	126 (78.8)	< 0.001
Time to ROSC, median (IQR), minutes	15 (8, 26)	20 (12, 30)	12 (8, 23)	< 0.001
Number of cycles of CPR, median (IQR)	7 (4, 10)	8 (5, 11)	6 (4, 10)	0.06
Number of doses of adrenaline, median (IQR)	3 (2, 4)	3 (2, 4)	3 (2, 4)	0.65
Reversible cause identified	198 (76.2)	53 (58.2)	145 (85.8)	< 0.001
Shifted to ICU2	188 (72.3)	72 (79.3)	116 (68.6)	0.08
Survival at 24-hour	142 (54.6)	58 (63.0)	84 (49.7)	0.04
Survival to hospital discharge among ROSC	56 (21.5)	27 (29.7)	29 (17.2)	0.03

¹Indicates those who received the first dose of adrenaline within 2 minutes; data on time of adrenaline administration available only in 242 patients.

²Not all patients who achieved return of spontaneous circulation were shifted to the intensive care unit; this decision was based on the clinicians’ assessment and the family’s wishes.

IQR: Interquartile range; ROSC: Return of spontaneous circulation; CPR: Cardiopulmonary resuscitation; ICU: Intensive care unit.

Table 3 Comparison of patients who received adrenaline within 2 minutes of arrest vs those who didn’t¹

Parameter	All patients (n = 426)2	Adrenaline ≤ 2 minutes (n = 274)	Adrenaline > 2 minutes (n = 152)	P value
Age, mean ± SD years	52.7 ± 16.0	51.7 ± 16.0	54.5 ± 16.0	0.08
Gender, male	270 (63.4)	172 (62.8)	98 (64.5)	0.75
Initial arrest rhythm
Asystole	402 (94.4)	261 (95.3)	141 (92.8)	0.28
PEA	24 (5.6)	13 (4.7)	11 (7.2)
Time to CART activation, median (IQR)	2 (1, 5)	1 (0, 3)	3 (1, 6)	< 0.001
Number of cycles of CPR, median (IQR)	10 (6, 16)	9 (5, 15)	10 (7, 16)	0.02
Number of adrenaline doses, median (IQR)	4 (2, 7)	4 (3, 7)	4 (2, 6)	0.08
Reversible cause identified	304 (71.4)	213 (77.7)	91 (60)	< 0.001
Outcomes among those who achieved ROSC
Number who achieved ROSC	242 (56.8)	166 (60.6)	76 (50)	0.04
Time to achieve ROSC, median (IQR)	16 (10, 28)	14 (8, 26)	20.5 (12, 30)	0.006
Survival at 24 hours following ROSC	130 (53.7)	87 (52.4)	43 (56.6)	0.58
Survival to hospital discharge among ROSC	47 (19.4)	29 (17.5)	18 (23.7)	0.29

¹Data was available only for 426 patients; all values are numbers (n) and percentages (%) unless specified.

²The time of administration of adrenaline was available only for 426 of the 450 patients.

IQR: Interquartile range; ROSC: Return of spontaneous circulation; CPR: Cardiopulmonary resuscitation; CART: Cardiac arrest resuscitation team; PEA: Pulseless electrical activity.

Table 4 Factors associated with return of spontaneous circulation¹

Parameter	Bivariate analysis OR (95%CI)	P value	Multivariate analysis OR (95%CI)	P value
Age	0.99 (0.98-1.00)	0.052	0.98 (0.97-1.0)	0.14
Female gender	0.93 (0.63-1.37)	0.78
Post-intervention period	1.11 (0.75-1.64)	0.61
PEA arrest	0.47 (0.2-1.06)	0.072	0.45 (0.19-1.07)	0.07
Time to CART activation	0.95 (0.91-0.98)	0.0063
Time to CART arrival	0.94 (0.91-0.98)	0.0022	0.96 (0.92-1.00)	0.05
Time to first adrenaline	0.94 (0.89-0.99)	0.032	0.97 (0.92-1.03)	0.33
Adrenaline within 2 minutes	0.65 (0.44-0.97)	0.043
Reversible cause	1.99 (1.32-3.0)	0.0012	1.71 (1.10-2.67)	0.02

¹A total of 260 patients (57.8%) achieved return of spontaneous circulation. On bivariate logistic regression analysis, age, time to cardiac arrest resuscitation team activation and arrival, time to first dose of adrenaline, adrenaline within 2 minutes and a reversible cause were associated with return of spontaneous circulation.

²Incorporated into multivariable logistic regression analysis.

³Not incorporated into the model; on multivariate logistic regression analysis, lower age, less.

PEA: Pulseless electrical activity; OR: Odds ratio; CI: Confidence interval; CART: Cardiac arrest resuscitation team.

Table 5 Factors associated with hospital mortality¹

Parameter	Bivariate analysis OR (95%CI)	P value	Multivariate analysis OR (95%CI)	P value
Age	1.01 (1.0-1.03)	0.092	1.01 (0.99-1.03)	0.19
Female gender	1.06 (0.59-1.90)	0.85
Post-intervention period	1.79 (1.02-3.14)	0.042	1.89 (1.04-3.43)	0.04
PEA arrest	0.73 (0.24-2.22)	0.58
Time to CART activation	0.98 (0.93-1.04)	0.53
Time to CART arrival	0.98 (0.93-1.03)	0.42
Time to first adrenaline	1.0 (0.92-1.08)	0.96
Adrenaline within 2 minutes	0.88 (0.47-1.65)	0.69
Number of CPR cycles	1.19 (1.15-1.28)	< 0.0012	1.19 (1.11-1.28)	< 0.001
Reversible cause	1.12 (0.62-2.05)	0.71

¹For mortality analysis, discharge against medical advice was included with deaths to reflect unfavourable outcomes. A total of 56 patients (12.4%) survived to hospital discharge. On bivariate logistic regression analysis, mortality was higher in the post-intervention period and among those who had more cycles of cardiopulmonary resuscitation.

²Incorporated into multivariable logistic regression analysis. On multivariate logistic regression analysis incorporating age, intervention period and number of cardiopulmonary resuscitation cycles, the post-intervention period and number of cardiopulmonary resuscitation cycles were independently associated with mortality.

OR: Odds ratio; CI: Confidence interval; PEA: Pulseless electrical activity; CPR: Cardiopulmonary resuscitation; CART: Cardiac arrest resuscitation team.

Table 6 Comparison of outcomes between pre-intervention and post-intervention periods for all patients and excluding in-hospital cardiac arrest during coronavirus disease era¹

Discrete variables	All patients		Excluding COVID era
	OR/median difference (95%CI)	P value	OR/median difference (95%CI)	P value
Timely adrenaline2	3.39 (2.18-5.29)	< 0.001	3.47 (2.10-5.74)	< 0.001
Number obtained ROSC	1.10 (0.74-1.67)	0.61	1.19 (0.75-1.89)	0.43
Number shifted to ICU	0.84 (0.56-1.27)	0.39	0.82 (0.52-1.29)	0.37
Survival at 24-hour	0.74 (0.48-1.14)	0.15	0.84 (0.52-1.36)	0.46
Mortality	1.79 (0.97-3.26)	0.04	1.61 (0.82-3.21)	0.14
Time to 1st adrenaline, minutes	2 (1-2)	< 0.001	2 (1-2)	< 0.001
No. of doses of adrenaline	-1 (-1 to 0)	0.007	-1 (-1 to 0)	0.01
No. of cycles of CPR	0 (-2 to 1)	0.62	0 (-1 to 1)	0.80

¹For all patients, mortality was higher in the post-intervention period when compared with the post-intervention period. There was no difference in the number of patients who achieved return of spontaneous circulation in the two periods. However, timely administration of adrenaline was significantly more likely in the post-intervention period when compared with the pre-intervention period. The number who were shifted to intensive care unit and were alive at 24-hour were not significantly different. Sensitivity analysis with the exclusion of in-hospital cardiac arrest during the coronavirus disease era (defined as the period from June 1, 2020 till August 31, 2021) showed that the results were unchanged except for mortality, which became insignificant with the exclusion of the coronavirus disease era in-hospital cardiac arrests.

²Indicates administration of the 1^st dose of adrenaline within 2 minutes.

CPR: Cardiopulmonary resuscitation; ROSC: Return of spontaneous circulation; IHCA: In-hospital cardiac arres; OR: Odds ratio; CI: Confidence interval; ICU: Intensive care unit; COVID: Coronavirus disease.