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Passive oxygenation with non-rebreather face mask (NRFM) has been used during cardiac arrest as an alternative to positive pressure ventilation (PPV) with bag-valve-mask (BVM) to minimize chest compression disruptions. A dual-channel pharyngeal oxygen delivery device (PODD) was created to open obstructed upper airways and provide oxygen at the glottic opening. It was hypothesized for this study that the PODD can deliver oxygen as efficiently as BVM or NRFM and oropharyngeal airway (OPA) in a cardiopulmonary resuscitation (CPR) manikin model.
Methods:
Oxygen concentration was measured in test lungs within a resuscitation manikin. These lungs were modified to mimic physiologic volumes, expansion, collapse, and recoil. Automated compressions were administered. Five trials were performed for each of five arms: (1) CPR with 30:2 compression-to-ventilation ratio using BVM with 15 liters per minute (LPM) oxygen; continuous compressions with passive oxygenation using (2) NRFM and OPA with 15 LPM oxygen, (3) PODD with 10 LPM oxygen, (4) PODD with 15 LPM oxygen; and (5) control arm with compressions only.
Results:
Mean peak oxygen concentrations were: (1) 30:2 CPR with BVM 49.3% (SD = 2.6%); (2) NRFM 47.7% (SD = 0.2%); (3) PODD with 10 LPM oxygen 52.3% (SD = 0.4%); (4) PODD with 15 LPM oxygen 62.7% (SD = 0.3%); and (5) control 21% (SD = 0%). Oxygen concentrations rose rapidly and remained steady with passive oxygenation, unlike 30:2 CPR with BVM, which rose after each ventilation and decreased until the next ventilation cycle (sawtooth pattern, mean concentration 40% [SD = 3%]).
Conclusions:
Continuous compressions and passive oxygenation with the PODD resulted in higher lung oxygen concentrations than NRFM and BVM while minimizing CPR interruptions in a manikin model.
Airway management is a cornerstone in the prehospital care of critically ill or injured patients. Surgical cricothyrotomy offers a rapid and effective solution when oxygenation and ventilation fail using less-invasive techniques. However, the exact indications, incidence, and success of prehospital surgical cricothyrotomy are unknown, with variable rates reported in the literature. This study aimed to examine prehospital indications and success rates for surgical cricothyrotomy within a large, suburban, ground-based Emergency Medical Services (EMS) system.
Methods:
This is a retrospective analysis of 31 patients who underwent paramedic performed surgical cricothyrotomy from 2012 through 2022. Key demographic parameters were analyzed, including the incidence of cardiac arrest, call type (trauma versus medical), initial airway management attempts, number of endotracheal intubation (ETI) attempts before surgical airway, and average time to the establishment of a surgical airway in relation to the number of ETI attempts. Surgical cricothyrotomy success was defined as the acquisition of four-phase end-tidal capnography reading. The primary data sources were the EMS electronic medical records, and descriptive statistics were calculated.
Results:
A total of 31 patients were included in the final analysis. Of those who received a surgical cricothyrotomy, 42% (13/31) occurred in the trauma setting, while 58% (18/31) were medical calls. In all patients who underwent surgical cricothyrotomy, the median (IQR) time to the procedure was 17 minutes (IQR = 11-24). In trauma patients, the median time to surgical cricothyrotomy was 12 minutes (IQR = 9-19) versus 19 minutes (IQR = 14-33) in medical patients. End-tidal carbon dioxide (ETCO2) detection and placement success was confirmed in 94% (29/31) of patients. Endotracheal intubation was attempted in 55% (17/31) before subsequent surgical cricothyrotomy, with 29% (9/31) receiving more than one ETI attempt. The median time to surgical cricothyrotomy when multiple prior intubation attempts occurred was 33 minutes (IQR = 23-36) compared to 14.5 minutes (IQR = 6-19) in patients without a preceding intubation attempt.
Conclusion:
Prehospital surgical airway can be performed by paramedics with a high degree of success. Identification of the need for surgical cricothyrotomy should be determined as soon as possible to allow for rapid securement of the airway and to ensure adequate oxygenation and ventilation.
The use of personal protective equipment (PPE) in prehospital emergency care has significantly increased since the onset of the coronavirus disease 2019 (COVID-19) pandemic. Several studies investigating the potential effects of PPE use by Emergency Medical Service providers on the quality of chest compressions during resuscitation have been inconclusive.
Study Objectives:
This study aimed to determine whether the use of PPE affects the quality of chest compressions or influences select physiological biomarkers that are associated with stress.
Methods:
This was a prospective randomized, quasi-experimental crossover study with 35 Emergency Medical Service providers who performed 20 minutes of chest compressions on a manikin. Two iterations were completed in a randomized order: (1) without PPE and (2) with PPE consisting of Tyvek, goggles, KN95 mask, and nitrile gloves. The rate and depth of chest compressions were measured. Salivary cortisol, lactate, end-tidal carbon dioxide (EtCO2), and body temperature were measured before and after each set of chest compressions.
Results:
There were no differences in the quality of chest compressions (rate and depth) between the two groups (P >.05). After performing chest compressions, the group with PPE did not have elevated levels of cortisol, lactate, or EtCO2 when compared to the group without PPE, but did have a higher body temperature (P <.001).
Conclusion:
The use of PPE during resuscitation did not lower the quality of chest compressions, nor did it lead to higher stress-associated biomarker levels, with the exception of body temperature.
Acute gastroenteritis (AGE) is one of the most common clinical diagnoses globally, and dehydration in severe AGE cases can cause severe morbidity and mortality. Depending on the metabolic acidosis that occurs in dehydration, the respiratory rate per minute is increased, and the carbon dioxide pressure in the arterial blood is decreased. This condition correlates with end-tidal carbon dioxide (ETCO2). Therefore, this study primarily aims to evaluate whether ETCO2 measurement has a role in detecting metabolic fluid deficit, dehydration level, and regression in dehydration level after fluid replacement and its correlation with Vena Cava Collapsibility Index (VCCI).
Material and Method:
This study included spontaneously breathing patients admitted to the emergency department of a tertiary training and research hospital with symptoms of AGE and were thought to be moderately (6.0%-9.0%) and severely (>10.0%) dehydrated according to the Primary Options of Acute Care (POAC) Clinical Dehydration Scale. After the first evaluation, the patients’ vital signs, ETCO2 values, diameters of the inferior vena cava (IVC) in inspiration and expiration, and VCCI were measured and recorded. These measurements were repeated after intravenous (IV) fluid replacement, and finally, a comparison was made between the measurements.
Results:
A total of 49 patients, as 16 male (32.7%) and 33 female (67.3%), were included in the study. The mean fluid replacement value was calculated as 664.29 (SD = 259.41) ml. The mean increase in ETCO2 was 3.653 (SD = 2.554) mmHg (P <.001). The mean increase in inferior vena cava expirium (IVCexp) was calculated as 0.402 (SD = 0.280) cm (P <.001) and the mean increase in inferior vena cava inspirium (IVCinsp) as 0.476 (SD = 0.306) cm (P <.001). The VCCI (%) decreased by 12.556 (SD = 13.683) (P <.001). Post-replacement vital signs, ETCO2, and VCCI correlations of the patients were examined and no significant correlation was found between ETCO2 and VCCI (%). As a result of this study, a receiver operating characteristic (ROC) curve was established for the ETCO2 values predicting the level of dehydration and fluid response, and the area under the curve was calculated as 0.748. However, to classify the patient as moderately dehydrated, the ETCO2 cutoff value was determined as 28.5mmHg.
Conclusion:
The sensitivity and specificity of ETCO2 levels were 71.43% and 74.29% in evaluating the level of dehydration, and no correlation was found with VCCI, which is known to have high sensitivity and specificity in previous studies in determining the level of dehydration and fluid response. Hence, VCCI measurement made through ultrasonography (USG) is a method that should be preferred more in determining the level of dehydration. Nevertheless, as per the results of this study, swift ETCO2 measurements may be helpful in monitoring the change in the degree of dehydration with treatment in patients who were admitted to the emergency department with dehydration findings and were administered IV fluid replacement therapy.
Airway management is a controversial topic in modern Emergency Medical Services (EMS) systems. Among many concerns regarding endotracheal intubation (ETI), unrecognized esophageal intubation and observations of unfavorable neurologic outcomes in some studies raise the question of whether alternative airway techniques should be first-line in EMS airway management protocols. Supraglottic airway devices (SADs) are simpler to use, provide reliable oxygenation and ventilation, and may thus be an alternative first-line airway device for paramedics. In 2019, Alachua County Fire Rescue (ACFR; Alachua, Florida USA) introduced a novel protocol for advanced airway management emphasizing first-line use of a second-generation SAD (i-gel) for patients requiring medication-facilitated airway management (referred to as “rapid sequence airway” [RSA] protocol).
Study Objective:
This was a one-year quality assurance review of care provided under the RSA protocol looking at compliance and first-pass success rate of first-line SAD use.
Methods:
Records were obtained from the agency’s electronic medical record (EMR), searching for the use of the RSA protocol, advanced airway devices, or either ketamine or rocuronium. If available, hospital follow-up data regarding patient condition and emergency department (ED) airway exchange were obtained.
Results:
During the first year, 33 advanced airway attempts were made under the protocol by 23 paramedics. Overall, compliance with the airway device sequence as specified in the protocol was 72.7%. When ETI was non-compliantly used as first-line airway device, the first-pass success rate was 44.4% compared to 87.5% with adherence to first-line SAD use. All prehospital SADs were exchanged in the ED in a delayed fashion and almost exclusively per physician preference alone. In no case was the SAD exchanged for suspected dislodgement evidenced by lack of capnography.
Conclusion:
First-line use of a SAD was associated with a high first-pass attempt success rate in a real-life cohort of prehospital advanced airway encounters. No SAD required emergent exchange upon hospital arrival.
Paramedics received training in point-of-care ultrasound (POCUS) to assess for cardiac contractility during management of medical out-of-hospital cardiac arrest (OHCA). The primary outcome was the percentage of adequate POCUS video acquisition and accurate video interpretation during OHCA resuscitations. Secondary outcomes included POCUS impact on patient management and resuscitation protocol adherence.
Methods:
A prospective, observational cohort study of paramedics was performed following a four-hour training session, which included a didactic lecture and hands-on POCUS instruction. The Prehospital Echocardiogram in Cardiac Arrest (PECA) protocol was developed and integrated into the resuscitation algorithm for medical non-shockable OHCA. The ultrasound (US) images were reviewed by a single POCUS expert investigator to determine the adequacy of the POCUS video acquisition and accuracy of the video interpretation. Change in patient management and resuscitation protocol adherence data, including end-tidal carbon dioxide (EtCO2) monitoring following advanced airway placement, adrenaline administration, and compression pauses under ten seconds, were queried from the prehospital electronic health record (EHR).
Results:
Captured images were deemed adequate in 42/49 (85.7%) scans and paramedic interpretation of sonography was accurate in 43/49 (87.7%) scans. The POCUS results altered patient management in 14/49 (28.6%) cases. Paramedics adhered to EtCO2 monitoring in 36/36 (100.0%) patients with an advanced airway, adrenaline administration for 38/38 (100.0%) patients, and compression pauses under ten seconds for 36/38 (94.7%) patients.
Conclusion:
Paramedics were able to accurately obtain and interpret cardiac POCUS videos during medical OHCA while adhering to a resuscitation protocol. These findings suggest that POCUS can be effectively integrated into paramedic protocols for medical OHCA.
In the absence of evidence of acute cerebral herniation, normal ventilation is recommended for patients with traumatic brain injury (TBI). Despite this recommendation, ventilation strategies vary during the initial management of patients with TBI and may impact outcome. The goal of this systematic review was to define the best evidence-based practice of ventilation management during the initial resuscitation period.
Methods:
A literature search of PubMed, CINAHL, and SCOPUS identified studies from 2009 through 2019 addressing the effects of ventilation during the initial post-trauma resuscitation on patient outcomes.
Results:
The initial search yielded 899 articles, from which 13 were relevant and selected for full-text review. Six of the 13 articles met the inclusion criteria, all of which reported on patients with TBI. Either end-tidal carbon dioxide (ETCO2) or partial pressure carbon dioxide (PCO2) were the independent variables associated with mortality. Decreased rates of mortality were reported in patients with normal PCO2 or ETCO2.
Conclusions:
Normoventilation, as measured by ETCO2 or PCO2, is associated with decreased mortality in patients with TBI. Preventing hyperventilation or hypoventilation in patients with TBI during the early resuscitation phase could improve outcome after TBI.
Out-of-hospital cardiac arrest (OHCA) is a leading cause of death in the United States, and efforts have been made to develop termination of resuscitation protocols utilizing clinical criteria predictive of successful resuscitation and survival to discharge. A termination of resuscitation protocol utilizing longer resuscitation time and end-tidal carbon dioxide (EtCO2) monitoring criteria for termination was implemented for Emergency Medical Service (EMS) providers in an urban prehospital system in 2017. This study examines the effect the modified termination of resuscitation protocol had on rates of patient transport to a hospital, return of spontaneous circulation (ROSC), and survival to discharge.
Methods:
A retrospective analysis was performed utilizing data from the Cardiac Arrest Registry to Enhance Survival (CARES) database. A total of 1,005 prehospital cardiac arrest patients 18 years and older from 2016 through 2017 were included in the analysis. Patients with traumatic cardiac arrest or had valid do-not-resuscitate orders were excluded. Unadjusted analysis using chi-square statistics was performed, including an analysis stratified by Utstein style reporting. Adjusted analysis was also performed using logistic regression with multiple imputation for missing values.
Results:
Unadjusted analysis showed a significant decrease in ROSC on emergency department (ED) arrival (30% versus 13%; P <.001) following the change in protocol. There was no significant difference in patient transport rate (62%) and a statistically non-significant decrease in overall survival (15% versus 11%). When stratified by Utstein style analysis, statistically significant decreases in ED arrival with ROSC were seen for unwitnessed asystolic, as well as bystander witnessed asystolic, pulseless electrical activity (PEA), and shockable OHCA. Adjusted analysis showed a decreased likelihood of ROSC with the protocol change (0.337; 95% CI, 0.235-0.482).
Conclusion:
The modification of termination of resuscitation protocol was not associated with a statistically significant change in transport rate or survival. A significant decrease in rate of arrivals to the ED with ROSC was seen, particularly for bystander witnessed OHCA.
End-tidal carbon dioxide (EtCO2) is a non-invasive method giving information about the perfusion, ventilation, and metabolic condition of patients. The correlation was studied here between the metabolic (pH, bicarbonate) values and EtCO2 during the treatment of diabetic ketoacidosis (DKA).
Case Report:
A 23-year-old male patient with diabetes mellitus was admitted to the emergency department (ED) with the complaints of nausea, vomiting, and fever. The patient with a diagnosis of DKA was continuously monitored with EtCO2; EtCO2 was correlated with serum bicarbonate (HCO3; r = 0.96; P < .001) and pH (r = 0.93; P < .001).
Conclusion:
Continuous EtCO2 monitoring should be considered by emergency physicians in the metabolic monitoring of the patients as it is an easy-to-use, non-invasive, and cost-effective method that provides instant and reliable information.
In October 2017, the American Association of Blood Bankers (AABB; Bethesda, Maryland USA) approved a petition to allow low-titer group O whole blood as a standard product without the need for a waiver. Around that time, a few Texas, USA-based Emergency Medical Services (EMS) systems incorporated whole blood into their ground ambulances. The purpose of this project was to describe the epidemiology of ground ambulance patients that received a prehospital whole blood transfusion. The secondary aim of this project was to report an accounting analysis of these ground ambulance prehospital whole blood programs.
Methods:
The dataset came from the Harris County Emergency Service District 48 Fire Department (HCESD 48; Harris County, Texas USA) and San Antonio Fire Department (SAFD; San Antonio, Texas USA) whole blood Quality Assurance/Quality Improvement (QA/QI) databases from September 2017 through December 2018. The primary outcome of this study was the prehospital transfusion indication. The secondary outcome was the projected cost per life saved during the first 10 years of the prehospital whole blood initiative.
Results:
Of 58 consecutive prehospital whole blood administrations, the team included all 58 cases. Hemorrhagic shock from a non-traumatic etiology accounted for 46.5% (95% CI, 34.3%-59.2%) of prehospital whole blood recipients. In the non-traumatic hemorrhagic shock cohort, gastrointestinal hemorrhage was the underlying etiology of hemorrhagic shock in 66.7% (95% CI, 47.8%-81.4%) of prehospital whole blood transfusion recipients. The projected average cost to save a life in Year 10 was US$5,136.51 for the combined cohort, US$4,512.69 for HCESD 48, and US$5,243.72 for SAFD EMS.
Conclusion:
This retrospective analysis of ground ambulance patients that receive prehospital whole blood transfusion found that non-traumatic etiology accounted for 46.5% (95% CI, 34.3%-59.2%) of prehospital whole blood recipients. Additionally, the accounting analysis suggests that by Year 10 of a ground ambulance whole blood transfusion program, the average cost to save a life will be approximately US$5,136.51.
This chapter discusses the basic methods and principles of monitoring for proper management of the critically ill patient in the emergency setting. Pulse oximetry provides continuous measurement of a patient's oxygenation status in the case of respiratory monitoring. Capnography measures the partial pressure or concentration of expired carbon dioxide (CO2), the end-tidal carbon dioxide (EtCO2). Ultrasonography of the inferior vena cava (IVC) can be useful in determining fluid responsiveness during non-invasive hemodynamic monitoring. Invasive hemodynamic monitoring provides data via catheters inserted in central veins or arteries. Central venous pressure is obtained by placing a central venous catheter (CVC) in the internal jugular or subclavian vein. The CVP should be interpreted with caution in critically ill patients that have known heart disease or structural cardiac anomalies. Pulse pressure variation (PPV) and systolic pressure variation (SPV) can be used to determine fluid responsiveness in a mechanically ventilated patient.
Continuous monitoring of end-tidal carbon dioxide (PETCO2) is a long-established standard of care in the operating room (OR). Carbon dioxide can be useful to monitor the mechanically ventilated patient when used in conjunction with other monitors of the patient's clinical status. CO2 monitoring is affected by changes in metabolism or CO2 production, cardiovascular function, and respiratory function. Comparison of the gradient between arterial and end-tidal CO2 (PaCO2-PetCO2) can offer valuable information regarding a patient's clinical status. In newborns, the therapeutic administration of CO2 in the ventilator circuit has been used in the preoperative management of hypoplastic left heart syndrome. Volumetric capnography or volumetric CO2 (VCO2) is the measurement of CO2 as a function of volume as opposed to time. When CO2 production increases with constant minute ventilation, PaCO2 will increase. Alveolar minute ventilation can be used as a guide for predicting the PaCO2 that may result from adjusting ventilation parameters.
Monitoring PETCO2 serves as a useful adjunct in weaning postoperative patients from mechanical ventilation. Several laboratory techniques are commonly used as adjuncts to clinical assessment of the adequacy of ventilation. This chapter focuses on the procedures that are utilized for weaning patients from the ventilator. Successful weaning during the postoperative period requires the assurance that the patient is clinically stable and without clinically significant residual effects of the anesthetic agents utilized during surgery. Some clinicians utilize PETCO2 as a marker of the metabolic rate and, therefore, as a way of determining optimal ventilator settings during the weaning process. A variety of different devices are available to the practitioner caring for these patients. Data from PETCO2 monitoring should be used in conjunction with information derived from a clinical evaluation of the patient.
This chapter discusses two roles for capnography in the assessment and treatment of patients in cardiac arrest. It evaluates the efficacy of cardiopulmonary resuscitation (CPR), and cessation of resuscitation. A number of animal studies have shown an excellent correlation between end-tidal carbon dioxide (PETCO2) and cardiac output during states of low flow and during CPR. An animal model with ultrasound flow probes and radioactive microspheres was used to examine the relationships between PETCO2 and cardiac output, cerebral perfusion, and renal perfusion. A number of studies have found that PETCO2 values may change transiently after the administration of intravenous epinephrine or sodium bicarbonate. One of several studies that examined the active compression/decompression CPR (active compression/decompression (ACD)/CPR) technique used PETCO2 as a marker for cardiac output to compare the hemodynamics generated by the ACD/CPR method to standard CPR in the out-of-hospital setting.
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