Effect of Delayed Admission to Intensive Care Units from the Emergency Department on the Mortality of Critically Ill Patients

AUTHORS

Mehmet Suleyman Sabaz ORCID 1 , * , Sinan Asar ORCID 1 , Zafer Cukurova ORCID 1 , Nagihan Sabaz ORCID 2 , Halil Doğan ORCID 3 , Gokhan Sertcakacilar ORCID 1

1 Department of Anesthesiology and Reanimation, Bakırköy Dr. Sadi Konuk Training and Research Hospital, University of Health Sciences, Istanbul, Turkey

2 Department of Pediatric Nursing, Faculty of Health Sciences, Marmara University, Istanbul, Turkey

3 Department of Emergency Medicine, Bakırköy Dr. Sadi Konuk Training and Research Hospital, Istanbul, Turkey

How to Cite: Sabaz M S, Asar S, Cukurova Z, Sabaz N, Doğan H, et al. Effect of Delayed Admission to Intensive Care Units from the Emergency Department on the Mortality of Critically Ill Patients, Iran Red Crescent Med J. Online ahead of Print ; 22(6):e102425. doi: 10.5812/ircmj.102425.

ARTICLE INFORMATION

Iranian Red Crescent Medical Journal: 22 (6); e102425
Published Online: June 27, 2020
Article Type: Research Article
Received: March 7, 2020
Revised: June 2, 2020
Accepted: June 14, 2020
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Abstract

Background: Increasing in emergency department need to critical care, the number of intensive care unit bed worldwide is inadequate to meet these applies.

Objectives: The aim of this study was to investigate the effect of waiting for admission to the Intensive Care Unit (ICU) in the Emergency Department (ED) on the length of stay in the ICU and the mortality of critically ill patients.

Methods: This retrospective cohort study carried out between January 2012 - 2019 patients admitted to the ICU of a training and research hospital. The data of 1297 adult patients were obtained by searching the Clinical Decision Support System.

Results: The data of the patients were evaluated in two groups as those considered to be delayed and non-delayed. It was determined that the delay of two hours increased the risk of mortality 1.5 times. Hazard Ratios (HR) was 1.548 (1.077 - 2.224). Patients whose ICU admission was delayed by 5 - 6 hours were found to have the highest risk in terms of mortality (HR = 2.291 [1.503 - 3.493]). A statistically significant difference was found in the ICU mortality, 28-day and, 90-day mortality between the two groups. ICU mortality for all patients’ general was 25.2% (327/1297). This rate was 11.4% (55/481) in the non-delayed group and 33.3% (272/816) in the delayed group (P < 0.001). The 28-day mortality rate for all patients’ general was 26.9% (349/1297). This rate was found to be 13.5% (65/481) in the non-delayed group and 34.8% (284/816) in the delayed group (P < 0.001). The 90-day mortality for all patients’ general was 28.4% (368/1297). This rate was 14.1% (68/481) in the non-delayed group and 36.8% (300/816) in the delayed group (P < 0.001).

Conclusions: Prolonged stay in the ED before admission to the ICU is associated with worse consequences, and increased mortality.

Copyright © 2020, Author(s). This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/) which permits copy and redistribute the material just in noncommercial usages, provided the original work is properly cited

1. Background

Critically ill patients are generally defined as physiologically unstable patients requiring continuous follow-up, close monitoring and treatment (1). Prolonged time from the early organ dysfunction to performing appropriate interventions in critically ill patients may have a direct impact on survival (2). Therefore, critically ill patients often require time-sensitive medical interventions to decrease mortality and morbidity (3-5). If septic shock occurred, rapid early fluid resuscitation and appropriate antibiotic treatment, arterial revascularization in myocardial infarction, aggressive resuscitation after major trauma, and thrombolytic therapy in stroke patients (6-10) are some of these interventions.

The increasing number of critically ill patients has become a major concern, as the global population is getting older and becoming morbid. Timely access from crowded emergency departments (EDs) to intensive care (IC) beds is becoming an increasingly significant problem (3, 11-13). In a study conducted on 17,900 patients admitted to EDs in the United States, 8.5% of patients admitted to ED and 25% of hospitalized patients are reported to be critically ill patients (14). Increasing demand worldwide brings about an insufficient number of beds in the intensive care unit (ICU) (15, 16). This demand often exceeds existing beds and resources in many hospitals all around the world. This leads to more complicated decisions made about the admission of patients to ICU (17, 18). While a large number of ICU beds causes admission of patients whose conditions are too good or too severe to be beneficial, a low number of ICU beds causes ICU triage decisions to be harder and rejection of patients who will benefit from ICU (18-20). When the number of patients requiring IC management is more than the number of available beds, ICU admission is delayed and critically ill patients are monitored in the ED where non-ICU personnel is present (21, 22). On the other hand, the literature shows that EDs are not designed, equipped, or staffed to provide the treatment and care required by critically ill patients (1, 21). Emergency physicians have limited time and nurses do not have a 1:1 or 1:2 nurse-to-patient ratio, which is present in most ICUs (16, 23-26). Whilst managing a patient requiring ICU in the ED, the physician often faces the dilemma of transferring the patient or monitoring him/her in the ED (16). While transferring the patient to another hospital means potential complications during the transfer, keeping the patient in the ED means taking the risk of a potential setback during the indefinite period of waiting for the ICU bed (27, 28).

Intensive care admission time varies among countries and hospitals. Critically ill patients spend hours or even days in ED while waiting for an IC bed to be available for them (16). This duration ranges from 2 hours to 3.5 days in 87% of patients waiting to be admitted to ICU in the ED (12, 17, 29-32). The American Hospital Association stated that the average waiting time to be transferred from the ED to the IC bed was 5.8 hours (33).

In previous studies, delayed admission to ICU was found to be associated with prolonged length of ICU and hospital stay and higher mortality (15, 16, 18, 29, 34). In pursuit of physiological deterioration, delays of four or more hours in ICU admission are associated with 3.5-fold increase in mortality (5). Even though the negative effects of extended ICU waiting time have been reported, some study results contradict others and show that there is no relationship between delayed admission and prolonged ICU and hospital stay and higher mortality (28, 31, 35-37).

Since previous studies show inconsistent results based on population and ED examined and there is limited available data nationwide, we esteem that a study on the relationship between admission to ICU from ED should be conducted.

2. Objectives

The aim of the present study was to investigate the effect of waiting for admission to the ICU in the ED on the length of stay in the ICU and the mortality of critically ill patients. The main outcomes of interest included 28-day and 90-day mortality and ICU length of stay.

3. Methods

3.1. Study Design and Setting

This a retrospective, observational cohort study was carried out at Health Sciences University, Bakırköy Dr. Sadi Konuk Training and Research Hospital between January 2012 and 2019 in Istanbul, Turkey. This hospital is a general government hospital which health services are provided free of charge to all citizens within the scope of social insurance. This referral hospital contains 40 different medical departments and 652 general ward sickbeds. The ICU of hospital has a 27 sickbeds and is an important health center in Istanbul, the most populous city in Europe, with a population of more than 15 million. The ICU accepts an average of 1346 medical, surgical and trauma patients per year who need medical treatment. ICU is a closed unit controlled by the clinical decision support system (CDSS) and medical applications such as extracorporeal treatments (extracorporeal membrane oxygenation (ECMO), hemodialysis, plasmapheresis) are carry out. The nurse-patient ratio is 1:2 in ICU.

The Emergency Department of the hospital provide 7/24 emergency health service by emergency physicians-nurses and admit an average of 280,000 patients a year. The ED implements a 5-stage triage system to patients (i.e., resuscitation, emergency, urgent, less urgent, and not urgent). Patients who are met by specially trained nurses and whose first complaints and medical history are taken, are carried to sickrooms specially designed for ED according to the severity and urgency of their complaints. Patients who are considered to need IC by the emergency physician are evaluated by the IC specialist or assistant physician before being admitted to the ICU. After the patients are evaluated, they are admitted to the ICU as soon as possible if sickbeds were available. If there is no vacancy in the ICU, the patient is transferred to other hospitals or treatment is continued in the ED while the waits for admission to the ICU. In country, the Ministry of Health electronically monitors the number of sickbeds in all ICUs and the number of transfers to ICUs of other hospitals with available sickbeds when no vacancies are available in the ICU. In addition, IC specialists cannot keep an ICU bed vacant or reserve one without justification per the regulation of the Ministry of Health.

3.2. Study Population and Sample

Between January 2012 and 2019, 9424 admissions were made to the ICU. In this period, all of the 1704 patients who admitted to the ICU from the ED was constituted the study population. A total of 1155 patients was calculated to detect a 9.4% reduction of absolute risk (12) with 95% confidence interval, 80% power, and a 1:2 non-exposure/exposure ratio. According to study inclusion criteria, 1297 patients was constituted the study population. No sample selection was made as it was aimed to reach the all study population. All of the 1297 patients were reached by scanning backwards in the study.

3.2.1. Inclusion Criteria

The inclusion criteria were as follows:

• Admission from the ED of the hospital to the ICU

• Patients who were followed for more than 24 hours in the ICU

• Patients who were admitted from other hospitals

• Without missing data

3.2.2. Exclusion Criteria

The exclusion criteria were as follows:

• Transfer to wards within the first 24 hours of ICU admission

• Admissions via theatre

• Transfer from other hospitals

• Admissions from wards

• Admissions from other hospital ICUs

• Dead within 24 hours

• Missing data

3.3. Ethical Considerations

Before conducting the study, ethical and institutional approval was obtained from Health Sciences University Bakırköy Dr. Sadi Konuk Training and Research Hospital Clinical Research Ethics Committee (Ethical code: 2019/21, ethical approval date: 07.01.2019, permission number: 2019-01-18). Written consent was obtained from all patients. The research conforms to the provisions of the Declaration of Helsinki in 1995 (as revised in Brazil 2013).

3.4. Data Collection

The data of the ED patients who were given ICU consultation were collected by searching the hospital electronic database EMRall-QlinICU CDSS, and the consultation response time to determine the patients’ ICU treatment decision was calculated. This registry system was containing the complete and continuous registration of all available data of the patients in ICU. The following demographic data were collected: age, gender, length of hospital stay, length of ICU stay, ICU admission diagnosis, and comorbidities, acute physiology and chronic health evaluation (APACHE) 2 score, APACHE 4 score, simplified acute physiology score (SAPS) 3 score, sequential organ failure assessment (SOFA) score, therapeutic intervention scoring system (TISS) 28 score, Glasgow coma scale (GSC) score on the first day of ICU, results of blood samples taken on the first day of ICU, need for mechanical ventilation (MV) and tracheal intubation, vasoactive agents use, invasive procedures used, treatments, and exit information.

3.5. Statistical Analysis

The data collected by the study were evaluated with the SPSS V. 22.00 program. The Shapiro-Wilk test was used to test the normal distribution of the data. Categorical variables were given as frequency (n) and percent (%), while numerical variables were given as median and interquartile ranges (IQR). The Mann-Whitney U test was used for the comparison of the quantitative data. A chi-square test was used to test categorical variables, and Fisher’s exact test was used when the conditions of the chi-square test could not be met. Since independent variables are not normally distributed and there may be proportional relationships between these values, the Cox regression model was used for the ICU mortality. After controlling the assumptions of the Cox regression model, the factors that may affect ICU mortality was implemented by entering the variables related to a stepwise backward method and then removing the non-meaningful variables. Cox regression analysis was used for variables affecting ICU mortality. The percentage of patients censored for surviving the ICU follow-up was 74.8% (972). Kaplan-Meier analysis was used for 28-day and 90-day mortality. The log rank test was used to determine the difference between groups. Since the patients with missing data were excluded the study and was reached all of the patients' mortality information, was no censored (missing data) data in the study sample. In the survival analysis used, did not have right-censored data. Patients who did not develop mortality during the follow-up period were identified as left-censored data. The level of significance was set as P = 0.05.

3.6. Primary Outcomes

The primary outcome was to compare the ICU mortality of ED patients who were admitted without delay to the ICU with those whose admission to the ICU was delayed.

3.7. Secondary Outcomes

The secondary outcomes were to determine the comorbidities of patients, diagnosis of admission, scores calculated after admission to the ICU, laboratory values, treatments, and 28-day and 90-day mortality. As most of the patients do have health insurance and their date of decease is included in the insurance and hospital database, we were able to assess re-admittance to the hospital, 28-day mortality and 90-day mortality endpoints.

4. Results

During the study period (2012 - 2019) there were 1704 ICU admissions. After excluding 188 patients who were transferred to other wards within the first 24 hours, 123 patients who died within the first 24 hours, and 96 patients with missing identity details, there were 1297 admissions included in the final analysis (Figure 1).

General comparisons between patient groups are presented in Table 1. The patients were divided into two groups: those who were admitted non- delayed to the ICU (37.1%; n = 481) and those whose admission to the ICU was delayed (62.9%; n = 816).

Patients were mainly male (58%), with a mean age of 60 (IQR, 40 - 75 years). The group admitted to the ICU non- delayed was younger than the other group (56 [37 - 73]). Of the patients, 61% had at least one comorbid disease, and comorbid diseases were found to be similar between the two groups. The most common admission diagnoses were multi-trauma (14.7%), pneumonia (14%), intracranial hemorrhage (11.8%), and sepsis (11.6%). A diagnosis of sepsis was most common in the group whose ICU admission was delayed, while intoxication was found to be the main diagnosis in the other group.

During ICU treatment, interventions such as a central catheter, dialysis catheter, thorax drain, and orotracheal intubation were applied more to the delayed admission group than to the other group. No statistically significant difference was found between the groups in terms of arterial catheter hemodialysis and tracheostomy interventions. Vasoactive agents (42.5%) and antibiotic therapy (74.4%) were used more frequently to the delayed group, while sedative drug use was found to be similar in the two groups.

Transfusion of blood and blood products was similar between the groups. The one exception difference was platelet use; platelet replacement therapy was applied more frequently to the group whose admission was delayed. No statistically significant difference was found between groups for the acute kidney injury (AKI) warning given by the CDSS. However, the CDSS gave more frequent septic shock warnings in the group whose admission was delayed (Table 1).

Flow diagram of patients selection
Figure 1. Flow diagram of patients selection
Table 1. Characteristics, Comorbidity, Diagnosis, Intervention, and Treatments of the Patientsa
ParametersTotal Sample (N = 1297)Non-Delayed (N = 481)Delayed (N = 816)P Value
Gender0.100
Male752 (58)293 (60.9)459 (56.25)
Female545 (42)188 (39.1)357 (43.75)
Age, median (IQR)60 (40–75)56 (37–73)61 (42–75)0.014
Comorbidity792 (61.1)291 (60.5)501 (61.4)0.749
Hypertension374 (28.8)125 (26.0)249 (30.5)0.082
Diabetes259 (20)91 (18.9)168 (20.6)0.468
CAD213 (16.4)80 (16.6)133 (16.3)0.876
CHF123 (9.5)47 (9.8)76 (9.3)0.786
Cerebrovascular disease100 (7.7)37 (7.7)63 (7.7)0.985
COPD131 (10.1)50 (10.4)81 (9.9)0.787
CRF121 (9.3)39 (8.1)82 (10)0.246
Dementia82 (6.3)30 (6.2)52 (6.4)0.923
Malignancy135 (10.4)44 (9.1)91 (11.2)0.254
Hepatic disease24 (1.9)11 (2.3)13 (1.6)0.371
Psychiatric disorder40 (3.1)17 (3.5)23 (2.8)0.471
Other138 (10.6)53 (11.0)85 (10.4)0.734
Admission diagnosis
Pulmonary308 (23.7)120 (24.9)188 (23.0)0.435
Pneumonia182 (14)69 (14.3)113 (13.8)0.859
COPD66 (5.1)31 (6.4)35 (4.3)0.088
ARDS24(1.9)9 (1.9)15 (1.8)0.966
Pulmonary, other36 (2.8)11 (2.3)25 (3.1)0.411
Trauma215 (16.6)81 (16.8)134 (16.4)0.845
Multi-trauma191 (14.7)71 (14.8)120 (14.7)0.978
Gunshot injuries/sharp object injury24 (1.9)10 (2.1)14 (1.7)0.639
Cranial198 (15.3)64 (13.3)134 (16.4)0.132
Intracranial bleeding153 (11.8 )53 (11)100 (12.3)0.505
Stroke45 (3.5)11 (2.3)34 (4.2)0.074
Cardiac 58 (4.5)22 (4.6)36 (4.4)0.892
MI 41 (3.2)17 (3.5)24 (2.4)0.555
Chronic HF17 (1.3)5 (1.0)12 (1.5)0.510
Sepsis151 (11.6)39 (8.1)112 (13.7)0.002
Intoxication123 (9.5)64 (13.3)59 (7.2)< 0.001
ARF - renal60 (4.6)24 (5.0)36 (4.4)0.632
DKA - metabolic40 (3.1)17 (3.5)23 (2.8)0.471
GIB - hemorrhage25 (1.9)6 (1.2)19 (2.3)0.171
Hepatic cirrhosis21 (1.6)10 (2.1)11 (1.3)0.314
Malignancy33 (2.5)9 (1.9)24 (2.9)0.237
SE16 (1.2)7 (1.5)9 (1.1)0.579
Pancreatic15 (1.2)3 (0.6)12 (1.5)0.192b
Other34 (2.6)15 (3.1)19 (2.3)0.390
Interventions
Hemodialysis173 (13.3)61 (12.7)112 (13.7)0.593
Arterial catheter740 (57.1)264 (54.9)476 (58.3)0.226
Central catheter490 (37.8)151 (31.4)339 (41.5)< 0.001
Dialysis catheter304 (23.4)93 (19.3)211 (25.9)0.007
Thorax drain79 (6.1)21 (4.4)58 (7.1)0.046
Nasogastric660 (50.9)223 (46.4)437 (53.6)0.012
MV826 (63.7)275 (57.2)551 (67.5)< 0.001
Tracheostomy198 (15.3)62 (12.9)136 (16.7)0.068
Treatments
Inotrope469 (36.2)122 (35.4)347 (42.5))< 0.001
Noradrenaline546 (42.1)166 (34.5)380 (46.6)< 0.001
Adrenaline144 (11.1)31 (6.4)113 (13.8)< 0.001
Dobutamine49 (3.8)14 (2.9)35 (4.3)0.208
Dopamine216 (16.7)51 (10.6)165 (20.2)< 0.001
Glypressin30 (2.3)9 (1.9)21 (2.6)0.416
Sedation738 (56.9)271 (56,3)467 (57.2)0.755
Antibiotics928 (71.5)321 (66.7)607 (74.4)0.003
Blood product181 (18.0)66 (18.0)115 (18.0)0.995
Erythrocyte suspension168 (13.0)59 (12.3)109 (13.4)0.572
Fresh frozen plasma99 (7.6)34 (7.1)65 (8.0)0.557
Platelets (109 cells/L)63 (4.9)16 (3.3)47 (5.8)0.049
Warning - alarm
AKI809 (62.4)301 (62.6)508 (62.3)0.908
Septic shock482 (37.2)153 (31.8)329 (40.3)0.002

Abbreviations: AKI, acute kidney injury; ARDS, acute respiratory distress syndrome; ARF, acute renal failure; CAD, coronary artery disease; CHF, congestive heart failure; COPD, chronic obstructive pulmonary disease; CRF, chronic renal failure; DKA, diabetic ketoacidosis; GIB, gastrointestinal bleed; HF, heart failure; IQR, interquartile range; MI, myocardial infarction; MV, mechanic ventilation; SE, status epilepticus.

aValues are expressed as No. (%).

bFisher’s exact test.

The duration of admission was 33 (18 - 46) minutes in the non- delayed group and 148 (98 - 252) minutes in the delayed group. After the patients’ admission to the ICU, APACHE2, APACHE4, SAPS3, TISS28, and SOFA scores were found to be statistically significantly higher in the delayed group, while the GCS score was significantly lower in the same group. White blood cell (WBC) and bilirubin were significantly higher in the delayed group. For other laboratory parameters, no statistically significant difference was found between the groups. The patients’ stay in the ICU was found to be 3.95 (2.0 - 8.33) days. No statistically significant difference was found between the patients’ duration of mechanical ventilator use and their duration of stay in the ICU (Table 2).

Table 2. Scores and Laboratory Parameters of Patients After Admission to the ICUa
ParametersTotal Sample (N = 1297)Non-Delayed (N = 481)Delayed (N = 816)P Value
Admission duration (min)90 (41 - 83)33 (18 - 46)148 (98 - 252)
IC scores
GCS12 (6 - 15)12 (7 - 15)11 (6 - 15)0.033
APACHE216 (10 - 22)14 (9 - 21)17 (11 - 23)< 0.001
APACHE470 (46 - 96)63 (41 - 88)74 (50 - 98)< 0.001
SAPS343 (33 - 56)42 (30 - 52)45 (34 - 58)< 0.001
SOFA6 (3 - 10)6 (2 - 9)7 (3 - 10)< 0.001
TISS2817 (12 - 23)15 (11 - 22)18 (12 - 24)< 0.001
Laboratory
pH7.37 (7.29 - 7.42)7.38 (7.30 - 7.42)7.36 (7.28 - 7.42)0.173
PO2, mmHg73.2 (43.2 - 111)72.7 (43.3 - 109.5)73.7 (43.1 - 111.9)0.908
PCO2, mmHg39.4 (33.1 - 47.6)39.3 (33.1 - 47.2)39.4 (33.1 - 48.2)0.577
Lac, mmol/L2.40 (1.49 - 4.48)2.30 (1.40 - 4.30)2.50 (1.49 - 4.49)0.062
WBC, × 109/L12.99 (8.99 - 18.09)12.4 (8.75 - 22.87)13.42 (9.13 - 18.85)0.024
PCT, ug/L0.7 (0.3 - 2.79)0.61 (0.28 - 2.50)0.75 (0.31 - 3.07)0.071
Cr, mg/dL0.90 (0.66 - 1.70)0.84 (0.64 - 1.37)0.96 (0.67 - 1,88)0.001
BILI, mg/dL0.61 (0.41 - 1.01)0.55 (0.41 - 0.93)0.64 (0.41 - 1.04)0.046
MV (h) (n = 826)100.1 (46.3 - 166.3)96.3 (46.4 - 158.5)103.8 (45.7 - 168.0)0.403
LOS ICU (day)3.95 (2.0 - 8.33)3.70 (2.0 - 8.0)4.18 (1.96 - 8.45)0.304

Abbreviations: APACHE, acute physiology and chronic health evaluation; BILI, bilirubin; Cr, creatinine; IQR, interquartile range; GCS, Glasgow coma scale; IC, intensive care; Lac, lactate; LOS, length of stay; MV, mechanical ventilation; PCO2, partial pressure of carbon dioxide; PCT, procalcitonin; PO2, partial pressure of oxygen; SAPS, simplified acute physiology; SOFA, sequential organ failure assessment; TISS, therapeutic intervention scoring system; WBC, white blood cell.

aValues are expressed as median (IQR).

4.1. Mortality Analysis

In-ICU general mortality, 28-day, and 90-day mortality were compared between the two groups, as shown in Table 3. During the study period, ICU mortality for all patients’ general was 25.2% (327 - 1297). This rate was 11.4% (55 - 481) in the non-delayed group and 33.3% (272 - 816) in the delayed group (P < 0.001). The patients were subdivided according to their admission diagnosis, and as a result of the analyses, the mortality of the patients with multi-trauma, pneumonia, intracranial hemorrhage, sepsis, chronic obstructive pulmonary disease (COPD), acute renal failure (ARF), and myocardial infarction (MI) was found to be higher in the non-delayed group. For the other admission diagnoses, no statistically significant difference was found between the groups in terms of mortality.

Table 3. Mortality
ParametersTotal SampleNon-DelayedDelayedP Value
ICU mortality 327 (25.2)55 (11.4)272 (33.3)< 0.001
28-day349 (26.9)65 (13.5)284 (34.8)< 0.001
90-day368 (28.4)68 (14.1)300 (36.8)< 0.001
Admission diagnosis
Multi-trauma1915 (7.0)26 (21.7)0.008
Pneumonia1827 (10.1)37 (32.4)0.001
Intra-cranial bleeding1535 (9.4)36 (36.0)< 0.001
Sepsis15111 (28.2)56 (50.0)0.018
Intoxication1230 (0)4 (6.8)0.050b
COPD660 (0)7 (20.0)0.009b
ARF - renal604 (16.7)21 (58.3)0.001b
MI - cardiac586 (27.3)20 (55.6)0.036
Cerebrovascular accident452 (18.2)12 (35.3)0.250b
DKA - metabolic402 (11.8)3 (13.0)0.646b
Pulmonary - other361 (9.1)7 (28.0)0.210b
ARDS242 (22.2)9 (60.0)0.084b
GIB - hemorrhage251 (16.7)10 (52.6)0,141b
Hepatic cirrhosis211 (10.0)3 (27.3)0.331b
Gunshot injuries - sharp object injury242 (20.0)3 (21.4)0.668b
Malignancy335 (55.6)11 (45.8)0.619
SE160 (0)1 (11.1)0.563b
Pancreatic150 (0)4 (33.3)0.363b
Other341 (6.7)2 (10.5)0.591
Total pulmonary30810 (8.3)60 (31.9)< 0.001
Total trauma2157 (8.6)29 (21.6)0.013
MI414 (23.5)13 (54.2)0.049b
Chronic HF172 (40.0)7 (58.3)0.437b
Total cranial1987 (10.9)48 (35.8)< 0.001

Abbreviations: ARDS, acute respiratory distress syndrome; ARI, ccute renal failure; COPD, chronic obstructive pulmonary disease; DKA, diabetic ketoacidosis; GIB, gastrointestinal bleed; HF, heart failure; ICU, intensive care unit; MI, myocardial infarction; SE, status epilepticus.

aValues are expressed as No. (%).

bFisher’s exact test.

Cox regression analysis was performed to determine the factors affecting ICU mortality. The risk of mortality was found to increase in the delayed group compared to the non- delayed group. In the group whose ICU admittance was delayed up to two hours, Hazard Ratios (HR) was 1.548 (1.077 - 2.224). In the group delayed 6 - 12 hours, HR increased to 1.959 (1.203 - 3190). Patients whose ICU admission was delayed by 5 - 6 hours were found to have the highest risk in terms of mortality (HR = 2.291 [1.503 - 3.493]). In addition, high APACHE 2 (HR = 1.029 [1.008 - 1.051]) and SAPS3 (HR = 1.015 [1.006 - 1.025]) scores, high lactate (HR = 1.078 [1.039 - 1.117]) and WBC (HR = 1.013 [1.002 - 1.024]) values, inotropic agent treatment (HR = 2.771 [2.075 - 3.700]), MV (HR = 9.916 [3.133 - 31.388]), and septic shock warning by the CDSS (HR = 1.911 [1.520 - 2.402]) were high risk factors for mortality (Table 4).

Table 4. Hazard Ratios for ICU Mortality
ICU Mortality95% CIP Value
Vacancy readyReference
< 2 h1.5481.077 - 2.2240.018
2 - 3 h1.8591.301 - 2.6570.001
3 - 4 h2.1231.415 - 3.184< 0.001
4 - 5 h2.2081.367 - 3.5660.001
5 - 6 h2.2911.503 - 3.493< 0.001
6 - 12 h 1.9591.203 - 3.1900.007
MV9.9163.133 - 31.388< 0.001
Lac, mmol/L1.0781.039 - 1.117< 0.001
APACHE2_first1.0291.008 - 1.0510.007
SAPS3_first1.0151.006 - 1.0250.001
APACHE4_first1.0000.995 - 1.0060.920
SOFA_first1.0010.965 - 1.0380.968
Inotrope agent2.7712.075 - 3.700< 0.001
Septic shock warning1.9111.520 - 2.402< 0.001
WBC, × 109/L1.0131.002 - 1.0240.019

Abbreviations: APACHE, acute physiology and chronic health evaluation; CI, confidence interval; HR, hazard ratio; ICU, intensive care unit; Lac, lactate; h, hour; MV, mechanic ventilation; SAPS, simplified acute physiology; SOFA, sequential organ failure assessment; WBC, white blood cell.

The Kaplan-Meier method was used to compare the 28-day and 90-day mortality between the delayed and non-delayed groups. A statistically significant difference was found in the 28-day and 90-day mortality between the groups (P < 0.001). The 28-day mortality rate for all patients’ general was 26.9% (349 - 1297). This rate was found to be 13.5% (65 - 481) in the non-delayed group and 34.8% (284 - 816) in the delayed group (log rank P < 0.001) (Figure 2).

The 90-day mortality for overall patients was 28.4% (368 - 1297). This rate was 14.1% (68 - 481) in the non-delayed group and 36.8% (300 - 816) in the delayed group (log rank P < 0.001) (Figure 3).

5. Discussion

In present study, it has been determined that there is a relationship between delayed admission to the ICU and a higher mortality rate. The intensive care unit mortality was lower in the group who did not wait in ED. Patients in the delayed admission group experienced an increase in APACHE II and SAPS3 scores despite the medical care provided by ED staff while patients were waiting for IC beds. This reflects that the physiological condition deteriorates during the waiting period. The ED are not designed to provide long-term care to critically ill patients (29). It is not surprising that delayed admission to ICU deteriorates patient outcomes since a great deal of advanced intervention performed on critically ill patients require personnel qualified on IC, supplies which are not available in ED, and staff has limited time. The fact that electronic IC is associated with reduced mortality and ICU stay of patients in ED waiting to be transferred to ICU and using less resource of ICU in the study by Kadar et al. has shown the effect of IC training and experience on patient outcomes. The ED crowd can reduce the quality of care due to delays in initiating treatments and the compliance with clinical guidelines. Previous studies have reported that prolonged bed waiting time in critically ill patients leads to the development of complications and an increased mortality rate (5, 15, 22).

In many studies conducted, the effects of ICU waiting time on patient outcomes have been examined and various results related to how long after staying in ED before being transferred to ICU is considered as delayed have been obtained pursuant to countries. In our study, before the admission to the ICU, the waiting time in the ED was determined to be 90 minutes. While the waiting period for ICU admission in ED in New Zealand was determined to be 3.9 hours, it was 4.6 hours in Spain, 4.8 hours in Finland, 2.2 hours in the Netherlands, 2.2 hours in Canada and 12.7 hours in Taiwan (5, 35, 37-40). Compared to these results, the admission time from ED to ICU is shorter in our hospital. This can be explained by the health policies of our country. If an IC bed cannot be found in any public hospital in our country, patients are transferred to the ICU of private hospitals and treatment expenses are covered by the state. This privilege granted to IC patients and the treatment expenses paid enabled the private sector to focus more on ICUs and increase the number of beds. This ensures that the waiting times of patients waiting for an ICU bed are shortened.

The difference of our study from previous studies is that we determined that mortality was decreased in the second hour of the waiting time, and the longer the waiting time is, the more evident mortality risk becomes, and after the sixth hour, the mortality risk starts to decrease compared to the early hours. In previous studies, it has been explained that the effect of waiting time increasing mortality shows up later. In a study conducted in the United States, more than 50,0000 critically ill patients in nearly 120 ICUs were examined and it was determined that ICU mortality increased in the ones who waited longer than 6 hours in ED (29). In another study, it was determined that a significant increase in mortality in the ED patients waiting for ICU beds started in the fourth hour and the mortality gap between them and patients who did not wait became evident in the early hours and decreased in the following hours (40). In contrast to these studies in which the evident mortality gap is explained with the longer periods of staying in the ED in accordance with our results, in a study recently conducted in the Netherlands in 6 training hospitals, it was determined that ICU mortality increased in the patients who waited over 2.4 hours for beds, similar to our results (21). In the same study, it was determined in the sub-analysis of the diagnoses that the waiting time of ED was associated with mortality only in cardiac arrest patients. Considering the effect of admission diagnosis on mortality alone, mortality was found to be higher in patients who were admitted to the hospital with the diagnoses of sepsis, intracranial hemorrhage, myocardial infarction, and multi-trauma. A triage to be applied in order for the ED crowds not to deteriorate the outcomes of these patients is thought to decrease the ICU bed waiting time and ICU mortality. It has been determined in the studies that waiting in ED more than 5 hours in stroke patients increased ICU mortality (41), in cranial patients, ED crowd increased door-to-imaging time (42) and increased door-to-needle time in myocardial infarction (43).

There is also a study that shows another reason for the delay in the admission is that capacity agitation as well as care provided in ED crowd and triage. This study shows that immediate admission is possible when two or more ICU beds are available compared to one or fewer beds (44). For this reason, utilizing ICU bed occupancy properly and timely brings about quicker admission when needed and lower capacity agitation.

In the study, the most common admission diagnosis was determined as trauma and secondly pneumonia in both groups, similar to the previous study results (40, 45). There are more sepsis patients in the waiting group. This is found to be particularly remarkable considering that early diagnosis and treatment is lifesaving for sepsis patients. The fact that the SOFA score of the patients waiting for beds is higher shows that deterioration in organ functions is increased within the waiting period. SOFA increase shows that golden hours in sepsis cannot be utilized effectively in patients waiting for beds (46). The fact that the CDSS gives septic shock warning more often in the group waiting in ED also supports this. In a study conducted in North America, it was found that required interventions antibiotic treatment being in the first place were administered to sepsis patients with delay in crowded ED and early goal-directed therapy rate was decreased (47). It is thought that vasoactive agents and antibiotic treatment to be administered to patients waiting for beds more frequently results from the fact that these patients have sepsis and thus the mortality rate is higher. In similar studies, it has been found that antibiotic use rate (22) and vasoactive agents use (5) are higher in the group waiting for the IC bed.

As a result of this study, 30-day and 90-day mortality rates were found to be higher in the delayed admission group. The increase in mortality even in the patients who survived the acute phase of the critical illness shows that delayed admission may be responsible for prolonged morbidity and mortality. Even though organ failures in patients with physiologically limited reserves do not cause mortality in the acute phase, it may result in mortality increase related to decompensated failures not responding to treatment in the long term. In a study analyzing 4 prospective cohort studies conducted in North America and Europe, delayed ICU stay was determined to be associated with 28-day mortality. In another multi-center study, the delay in admission to ICU more than 2.4 hours was found to increase the 30-day and 90-day mortality rates (21).

5.1. Conclusions

Delayed admission to ICU and prolonged waiting of critically ill patients in ED are associated with mortality. Mortality started to increase in the second hour of the delay. Using triage to diagnose particularly the patients who have illnesses in which early intervention is lifesaving and to determine the patients who will benefit the most from ICU service may reduce the mortality. Larger and multi-center studies are needed to determine patients and diagnoses that will benefit from ICU service for an objective triage.

5.2. Strengths and Limitations

The utmost strength of the study is the CDSS and the full data acquired for the main outcome measures of the patients involved in the study taken from electronic medical records by preventing human errors. Manually extracting additional data from hospital medical records provided more contextual information. In terms of limitations, the study was conducted in a large general hospital of a metropolitan city. The results could not be generalized Results may not be the same in Turkey or other countries. Another limitation is the retrospective selection of patients requiring ED-ICU admission. Some patients who required ICU admission may be immediately diagnosed and successfully treated by the emergency physician and therefore may not have received ICU treatment. Due to the presence of neurology and coronary ICUs in our hospital, it may have affected the incidence of critically ill patients with cardiac and neurological illnesses in this ICU.

Footnotes

References

  • 1.

    Khan BA, Shakeel N, Siddiqui EU, Kazi G, Khan IQ, Khursheed M, et al. Impact of delay in admission on the outcome of critically ill patients presenting to the emergency department of a tertiary care hospital from low income country. J Pak Med Assoc. 2016;66(5):509-16. [PubMed: 27183926].

  • 2.

    Doukhan L, Bisbal M, Chow-Chine L, Sannini A, Brun JP, Cambon S, et al. Respiratory events in ward are associated with later intensive care unit (ICU) admission and hospital mortality in onco-hematology patients not admitted to ICU after a first request. PLoS One. 2017;12(7). e0181808. doi: 10.1371/journal.pone.0181808. [PubMed: 28749989]. [PubMed Central: PMC5531489].

  • 3.

    Blow O, Magliore L, Claridge JA, Butler K, Young JS. The golden hour and the silver day: detection and correction of occult hypoperfusion within 24 hours improves outcome from major trauma. J Trauma. 1999;47(5):964-9. doi: 10.1097/00005373-199911000-00028. [PubMed: 10568731].

  • 4.

    Sebat F, Musthafa AA, Johnson D, Kramer AA, Shoffner D, Eliason M, et al. Effect of a rapid response system for patients in shock on time to treatment and mortality during 5 years. Crit Care Med. 2007;35(11):2568-75. doi: 10.1097/01.CCM.0000287593.54658.89. [PubMed: 17901831].

  • 5.

    Garcia-Gigorro R, de la Cruz Vigo F, Andres-Esteban EM, Chacon-Alves S, Morales Varas G, Sanchez-Izquierdo JA, et al. Impact on patient outcome of emergency department length of stay prior to ICU admission. Med Intensiva. 2017;41(4):201-8. doi: 10.1016/j.medin.2016.05.008. [PubMed: 27553889].

  • 6.

    Powers WJ, Rabinstein AA, Ackerson T, Adeoye OM, Bambakidis NC, Becker K, et al. Correction to: Guidelines for the Early Management of Patients With Acute Ischemic Stroke: 2019 Update to the 2018 Guidelines for the Early Management of Acute Ischemic Stroke: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association. Stroke. 2019;50(12):e440-1. doi: 10.1161/STR.0000000000000215. [PubMed: 31765293].

  • 7.

    Lilly CM, Zuckerman IH, Badawi O, Riker RR. Benchmark data from more than 240,000 adults that reflect the current practice of critical care in the United States. Chest. 2011;140(5):1232-42. doi: 10.1378/chest.11-0718. [PubMed: 21868469].

  • 8.

    Wunsch H, Linde-Zwirble WT, Angus DC, Hartman ME, Milbrandt EB, Kahn JM. The epidemiology of mechanical ventilation use in the United States. Crit Care Med. 2010;38(10):1947-53. doi: 10.1097/CCM.0b013e3181ef4460. [PubMed: 20639743].

  • 9.

    Herring AA, Ginde AA, Fahimi J, Alter HJ, Maselli JH, Espinola JA, et al. Increasing critical care admissions from U.S. emergency departments, 2001-2009. Crit Care Med. 2013;41(5):1197-204. doi: 10.1097/CCM.0b013e31827c086f. [PubMed: 23591207]. [PubMed Central: PMC3756824].

  • 10.

    McCaig LF, Burt CW. National Hospital Ambulatory Medical Care Survey: 2002 emergency department summary. Adv Data. 2004;(340):1-34. [PubMed: 15068333].

  • 11.

    Angus DC, Kelley MA, Schmitz RJ, White A, Popovich J Jr, Committee on Manpower for P, et al. Caring for the critically ill patient. Current and projected workforce requirements for care of the critically ill and patients with pulmonary disease: can we meet the requirements of an aging population? JAMA. 2000;284(21):2762-70. doi: 10.1001/jama.284.21.2762. [PubMed: 11105183].

  • 12.

    Cardoso LT, Grion CM, Matsuo T, Anami EH, Kauss IA, Seko L, et al. Impact of delayed admission to intensive care units on mortality of critically ill patients: a cohort study. Crit Care. 2011;15(1):R28. doi: 10.1186/cc9975. [PubMed: 21244671]. [PubMed Central: PMC3222064].

  • 13.

    Soni KD, Kaushik G, Gupta A, Singh V, Kumar S, Sagar S. From Emergency Department to Intensive Care Unit, Does The Delay Matter to Trauma Patients? J Emerg Trauma Shock. 2018;11(3):189-92. doi: 10.4103/JETS.JETS_132_17. [PubMed: 30429626]. [PubMed Central: PMC6182966].

  • 14.

    Fromm RE Jr, Gibbs LR, McCallum WG, Niziol C, Babcock JC, Gueler AC, et al. Critical care in the emergency department: a time-based study. Crit Care Med. 1993;21(7):970-6. doi: 10.1097/00003246-199307000-00009. [PubMed: 8319477].

  • 15.

    Al-Qahtani S, Alsultan A, Haddad S, Alsaawi A, Alshehri M, Alsolamy S, et al. The association of duration of boarding in the emergency room and the outcome of patients admitted to the intensive care unit. BMC Emerg Med. 2017;17(1):34. doi: 10.1186/s12873-017-0143-4. [PubMed: 29121883]. [PubMed Central: PMC5680599].

  • 16.

    Kadar RB, Amici DR, Hesse K, Bonder A, Ries M. Impact of Telemonitoring of Critically Ill Emergency Department Patients Awaiting ICU Transfer. Crit Care Med. 2019;47(9):1201-7. doi: 10.1097/CCM.0000000000003847. [PubMed: 31162198].

  • 17.

    Sprung CL, Geber D, Eidelman LA, Baras M, Pizov R, Nimrod A, et al. Evaluation of triage decisions for intensive care admission. Crit Care Med. 1999;27(6):1073-9. doi: 10.1097/00003246-199906000-00021. [PubMed: 10397207].

  • 18.

    Mathews KS, Durst MS, Vargas-Torres C, Olson AD, Mazumdar M, Richardson LD. Effect of Emergency Department and ICU Occupancy on Admission Decisions and Outcomes for Critically Ill Patients. Crit Care Med. 2018;46(5):720-7. doi: 10.1097/CCM.0000000000002993. [PubMed: 29384780]. [PubMed Central: PMC5899025].

  • 19.

    Robert R, Coudroy R, Ragot S, Lesieur O, Runge I, Souday V, et al. Influence of ICU-bed availability on ICU admission decisions. Ann Intensive Care. 2015;5(1):55. doi: 10.1186/s13613-015-0099-z. [PubMed: 26714805]. [PubMed Central: PMC4695477].

  • 20.

    Stelfox HT, Hemmelgarn BR, Bagshaw SM, Gao S, Doig CJ, Nijssen-Jordan C, et al. Intensive care unit bed availability and outcomes for hospitalized patients with sudden clinical deterioration. Arch Intern Med. 2012;172(6):467-74. doi: 10.1001/archinternmed.2011.2315. [PubMed: 22412076].

  • 21.

    Groenland CNL, Termorshuizen F, Rietdijk WJR, van den Brule J, Dongelmans DA, de Jonge E, et al. Emergency Department to ICU Time Is Associated With Hospital Mortality: A Registry Analysis of 14,788 Patients From Six University Hospitals in The Netherlands. Crit Care Med. 2019;47(11):1564-71. doi: 10.1097/CCM.0000000000003957. [PubMed: 31393321]. [PubMed Central: PMC6798749].

  • 22.

    Sagy I, Fuchs L, Mizrakli Y, Codish S, Politi L, Fink L, et al. Characteristics and outcomes of critically-ill medical patients admitted to a tertiary medical center with restricted ICU bed capacity. J Crit Care. 2018;43:281-7. doi: 10.1016/j.jcrc.2017.09.177. [PubMed: 28965037].

  • 23.

    Yarmohammadian MH, Rezaei F, Haghshenas A, Tavakoli N. Overcrowding in emergency departments: A review of strategies to decrease future challenges. J Res Med Sci. 2017;22:23. doi: 10.4103/1735-1995.200277. [PubMed: 28413420]. [PubMed Central: PMC5377968].

  • 24.

    Horwitz LI, Green J, Bradley EH. US emergency department performance on wait time and length of visit. Ann Emerg Med. 2010;55(2):133-41. doi: 10.1016/j.annemergmed.2009.07.023. [PubMed: 19796844]. [PubMed Central: PMC2830619].

  • 25.

    Trzeciak S, Rivers EP. Emergency department overcrowding in the United States: an emerging threat to patient safety and public health. Emerg Med J. 2003;20(5):402-5. doi: 10.1136/emj.20.5.402. [PubMed: 12954674]. [PubMed Central: PMC1726173].

  • 26.

    Derlet RW, Richards JR. Overcrowding in the nation's emergency departments: complex causes and disturbing effects. Ann Emerg Med. 2000;35(1):63-8. doi: 10.1016/s0196-0644(00)70105-3. [PubMed: 10613941].

  • 27.

    Peyrony O, Chevret S, Meert AP, Perez P, Kouatchet A, Pene F, et al. Direct admission to the intensive care unit from the emergency department and mortality in critically ill hematology patients. Ann Intensive Care. 2019;9(1):110. doi: 10.1186/s13613-019-0587-7. [PubMed: 31578641]. [PubMed Central: PMC6775178].

  • 28.

    Hsieh CC, Lee CC, Hsu HC, Shih HI, Lu CH, Lin CH. Impact of delayed admission to intensive care units on patients with acute respiratory failure. Am J Emerg Med. 2017;35(1):39-44. doi: 10.1016/j.ajem.2016.09.066. [PubMed: 27742520].

  • 29.

    Chalfin DB, Trzeciak S, Likourezos A, Baumann BM, Dellinger RP, Delay-Ed study group. Impact of delayed transfer of critically ill patients from the emergency department to the intensive care unit. Crit Care Med. 2007;35(6):1477-83. doi: 10.1097/01.CCM.0000266585.74905.5A. [PubMed: 17440421].

  • 30.

    Duke G, Green J, Briedis J. Survival of critically ill medical patients is time-critical. Crit Care Resusc. 2004;6(4):261-7. [PubMed: 16556104].

  • 31.

    Parkhe M, Myles PS, Leach DS, Maclean AV. Outcome of emergency department patients with delayed admission to an intensive care unit. Emerg Med (Fremantle). 2002;14(1):50-7. doi: 10.1046/j.1442-2026.2002.00286.x. [PubMed: 11993835].

  • 32.

    Simchen E, Sprung CL, Galai N, Zitser-Gurevich Y, Bar-Lavi Y, Gurman G, et al. Survival of critically ill patients hospitalized in and out of intensive care units under paucity of intensive care unit beds. Crit Care Med. 2004;32(8):1654-61. doi: 10.1097/01.ccm.0000133021.22188.35. [PubMed: 15286540].

  • 33.

    Group L. The results of the American Hospital Association survey of emergency department (ED) and hospital capacity. American Hosp Assoc; 2006.

  • 34.

    Young MP, Gooder VJ, McBride K, James B, Fisher ES. Inpatient transfers to the intensive care unit: delays are associated with increased mortality and morbidity. J Gen Intern Med. 2003;18(2):77-83. doi: 10.1046/j.1525-1497.2003.20441.x. [PubMed: 12542581]. [PubMed Central: PMC1494814].

  • 35.

    Carter AW, Pilcher D, Bailey M, Cameron P, Duke GJ, Cooper J. Is ED length of stay before ICU admission related to patient mortality? Emerg Med Australas. 2010;22(2):145-50. doi: 10.1111/j.1742-6723.2010.01272.x. [PubMed: 20534049].

  • 36.

    Haji K, Haji D, Tiruvoipati R, Bailey M, Le Blanc V, Botha JA. Impact of length of stay in emergency department on the outcome in patients with severe sepsis. Crit Care & Shock. 2010;13:132-7.

  • 37.

    Saukkonen KA, Varpula M, Rasanen P, Roine RP, Voipio-Pulkki LM, Pettila V. The effect of emergency department delay on outcome in critically ill medical patients: evaluation using hospital mortality and quality of life at 6 months. J Intern Med. 2006;260(6):586-91. doi: 10.1111/j.1365-2796.2006.01716.x. [PubMed: 17116010].

  • 38.

    Green RS, MacIntyre JK. Critical care in the emergency department: an assessment of the length of stay and invasive procedures performed on critically ill ED patients. Scand J Trauma Resusc Emerg Med. 2009;17:47. doi: 10.1186/1757-7241-17-47. [PubMed: 19778429]. [PubMed Central: PMC2761844].

  • 39.

    Thijssen W, Kraaijvanger N, Barten DG, Boerma MLM, Giesen P, Wensing M. Impact of a well-developed primary care system on the length of stay in emergency departments in the Netherlands: a multicenter study. BMC Health Serv Res. 2016;16:149. doi: 10.1186/s12913-016-1400-z. [PubMed: 27117479]. [PubMed Central: PMC4845371].

  • 40.

    Hung SC, Kung CT, Hung CW, Liu BM, Liu JW, Chew G, et al. Determining delayed admission to intensive care unit for mechanically ventilated patients in the emergency department. Crit Care. 2014;18(4):485. doi: 10.1186/s13054-014-0485-1. [PubMed: 25148726]. [PubMed Central: PMC4175615].

  • 41.

    Rincon F, Mayer SA, Rivolta J, Stillman J, Boden-Albala B, Elkind MS, et al. Impact of delayed transfer of critically ill stroke patients from the Emergency Department to the Neuro-ICU. Neurocrit Care. 2010;13(1):75-81. doi: 10.1007/s12028-010-9347-0. [PubMed: 20428969].

  • 42.

    Reznek MA, Murray E, Youngren MN, Durham NT, Michael SS. Door-to-Imaging Time for Acute Stroke Patients Is Adversely Affected by Emergency Department Crowding. Stroke. 2017;48(1):49-54. doi: 10.1161/STROKEAHA.116.015131. [PubMed: 27856953].

  • 43.

    Schull MJ, Vermeulen M, Slaughter G, Morrison L, Daly P. Emergency department crowding and thrombolysis delays in acute myocardial infarction. Ann Emerg Med. 2004;44(6):577-85. doi: 10.1016/j.annemergmed.2004.05.004. [PubMed: 15573032].

  • 44.

    Harris S, Singer M, Sanderson C, Grieve R, Harrison D, Rowan K. Impact on mortality of prompt admission to critical care for deteriorating ward patients: an instrumental variable analysis using critical care bed strain. Intensive Care Med. 2018;44(5):606-15. doi: 10.1007/s00134-018-5148-2. [PubMed: 29736785]. [PubMed Central: PMC6006241].

  • 45.

    Siletz A, Jin K, Cohen M, Lewis C, Tillou A, Cryer HM, et al. Emergency department length of stay in critical nonoperative trauma. J Surg Res. 2017;214:102-8. doi: 10.1016/j.jss.2017.02.079. [PubMed: 28624030].

  • 46.

    Lerner EB, Moscati RM. The golden hour: scientific fact or medical "urban legend"? Acad Emerg Med. 2001;8(7):758-60. doi: 10.1111/j.1553-2712.2001.tb00201.x. [PubMed: 11435197].

  • 47.

    Zhang Z, Bokhari F, Guo Y, Goyal H. Prolonged length of stay in the emergency department and increased risk of hospital mortality in patients with sepsis requiring ICU admission. Emerg Med J. 2019;36(2):82-7. doi: 10.1136/emermed-2018-208032. [PubMed: 30518642].

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