Ventilator Management WITH DR. BRIAN FULLER, Visiting Professor from Washington University School of Medicine in St. Louis
Should we address the mechanical ventilator early to prevent and mitigate complications?
There are close to 1 million patients on mechanical ventilation per year in the United States. Patients on mechanical ventilation have reported mortality rates of up to 25%. As emergency providers, we have the opportunity to positively impact the care of these critically ill patients through effective ventilator management in the emergency department (ED).
Ventilator-associated lung injury (VALI) was first thought to be related to diffuse barotrauma. With the advent of cross-sectional imaging, it was realized that the pattern of lung injury was heterogeneous, and there are still areas of “baby lung” available for ventilation. This area is small but not inherently stiff. Therefore, ventilation with high tidal volumes can destroy the small, functional lung available for gas exchange. The median time of onset of acute respiratory distress syndrome (ARDS) is day 1-2 of hospitalization. Ventilation with high tidal volumes has been shown repeatedly to increase the incidence of acute lung injury.1
Lung injury can occur in a very short period of time. A 1994 study showed that significant lung injury occurred after two hours of high tidal volumes and high peak airway pressures.2 This suggest the need for early and effective ventilator management as soon as the endotracheal tube is placed, i.e. in the ED. Additionally, one study showed that pre-hospital tidal volumes influence the tidal volume that is set in the ED and in the ICU. There is significant therapeutic momentum with this.3 In fact, a 23% increase in mortality has been seen in patients with an increase of 1 mL/kg predicted body weight in initial tidal volume set on the ventilator.4
The LOV-ED trial was a prospective trial evaluating the efficacy of a lung-protective ventilation strategy implemented in the ED. The protocol involved an initial tidal volume set at 6-8 mL/kg ideal body weight, and minimization of hyperoxia was mandatory. This protocol resulted in a drop in tidal volumes in the ICU and improved lung-protective ventilation during the ICU stay, again suggesting the therapeutic momentum of what happens in the ED that carries over to the ICU. The intervention group in this study had fewer ICU days, fewer hospital days, and a drop in mortality from 34.1% to 19.6%.4
So what can we do in the ED to improve our ventilator management? First, do not be afraid to measure your patient’s height. This will allow more appropriate calculation of the ideal body weight. Second, choose tidal volumes between 6-8 mL/kg. Third, minimize hyperoxia and wean oxygenation as aggressively as possible to maintain adequate saturations. Finally, keep in the mind the physiology of the patient in front of you. In patients with severe acidosis, perhaps a larger tidal volume is needed to prevent death from acidosis. Low tidal volumes should be considered an initial starting point, and adjustments can be made according to each individual patient’s needs. Remember that the ventilator dosing we choose in the ED may impact the patient’s illness and care in the ICU.
Determann R., Royakkers A., Wolthius E., Vlaar A., et al. Ventilation with lower tidal volumes as compared with conventional tidal volumes for patients without acute lung injury: a preventive randomized controlled trial. Crit Care, 2010; 14(1): R1.
Muscedere J., Mullen J., Gan K., Slutsky A. Tidal ventilation at ow airway pressures can augment lung injury. Am J Respr Crit Care Med, 1994; 149(5): 1327-1334.
Stoltze A., Wong T., Harland K., Ahmed A., et al. Prehospital tidal volume influences hospital tidal volume: a cohort study. J Crit Care, 2015; 30(3): 495-501.
Needham D., Yang T., Dinglas V., Mendez-Telles P., et al. Timing of low tidal volume ventilation and intensive care unit mortality in acute respiratory distress syndrome. A prospective cohort study. Am J Respr Crit Care Med, 2015; 191(2): 177-185
Fuller B., Ferguson I., Mohr N., Drewry A., et al. Lung-protective ventilation initiatied in the emergency department (LOV-ED): a study protocol for a quasi-experimental, before-after trial. Annals of Emergency Medicine, 2017; 70(3): 406-418.
Early Sedation WITH DR. BRIAN FULLER, Visiting Professor from Washington University School of Medicine in St. Louis
Is early deep sedation (RASS -3 to -5) a problem? Several studies have suggest that increased delirium is associated with deep sedation, and development of delirium may be associated with increased mortality.1 Additionally, early deep sedation is associated with delayed extubation. Deep sedation in the ED is common for a variety of reasons, and this may be an area where we can impact patient outcomes.2 One meta-analysis found some data to suggest that early assessment of sedation depth, with a goal to prevent deep sedation when possible, may help improve mortality.3 Similar to ventilator management, what we do in the ED impacts care in the ICU, and deep sedation in the ED is associated with deep sedation in the first 24 hours in the ICU as well. There is current a pilot trial in process evaluating sedation in the emergency department, and more data is needed to determine the effects this may have. In the meantime, be conscientious about your sedation given to patients in the ED as it may have a bigger impact than we realize on patient outcomes.
Shehabi Y., Bellomo R., Reade M., Bailey M., et al. Early intensive care sedation predicts long-term mortality in ventilated critically ill patients. Am J Respr Crit Care Med, 2012; 186(8): 724-731.
Stephens R., Ablordeppey E., Drewry A., Palmer C., et al. Analgosedation practices and the impact of sedation depth on clinical outcomes among patients requiring mechanical ventilation in the ED: A cohort study. Chest, 2017; 152(5): 963-971.
Stephens R., Dettmer M., Roberts B., Ablordeppey E., et al. Practice patterns and outcomes associated with earlysedation depth in mechanically ventilated patients: a systematic review and meta-analysis. Crit Care Med, 2018; 46(3): 471-479.
R4 Capstone- CDU Update WITH DR. HARRISON
According to the Medicare definition, observation services are defined as those services which are necessary to evaluate an outpatient’s condition or determine the need for inpatient admission. In general, an ED observation stay (i.e. CDU) is cheaper overall than an inpatient admission.
The pros of observation medicine are many. They include fewer penalties for misclassification, less 30 day re-admissions, less overcrowding, better resource utilization, potentially shortened lengths of stay, expeditious outpatient workups, fewer inappropriate discharges, and overall patient satisfaction improvement. The cons of observation medicine include a potential need for additional space, potentially increased cost for repeat visits, and occasional concerns with skilled nursing facility reimbursements.
The national average length of stay is about 15.5 hours. The most common presentations to CDU are chest pain and general protocols.
Ways to improve your CDU utilization:
Have a clear-cut end point. In general, significant work-ups should be avoided in CDU.
Replace electrolytes (predominantly potassium) in the ED because this is necessary to perform stress testing.
Call MRI (or stress, etc) to see when the test can be done. This will minimize CDU admissions that last less than eight hours (these are not paid by Medicare).
Clearly document your discussion with poison control for overdose patients. This helps with management and can clearly delineate work-up and length of observation necessary.
Clearly define an endpoint with your consultants.
Think twice about placing ESRD patients in CDU. It is often difficult to obtain dialysis from an observation unit.
Increasing oxygen demands in COPD patients generally have a high failure rate and do not go home within 24 hours.
Look up your observation inclusion and exclusion criteria before calling for admission.
If you have a question about appropriateness of a patient, call the CDU providers and ask. They have experience in CDU and can provide insight.
Always ask the patient if they are willing to stay before calling CDU.
R4 Case Follow-up- Acute Inhalation Injury from Chlorine Gas WITH DR. MCKEE
Ohio saw 363 cases of chlorine gas exposure last year. This comes from a variety of sources including various cleaning products. The combination of bleach and other acidic cleaners can produce chlorine gas, while bleach plus ammonia can produce chloramine gas. Swimming pool exposures are also reported as are a number of industrial exposures. This results in a chemical injury to the airway. Increased secretions, irritation of the mucous membranes, bronchospasm, pulmonary edema, and death can result from chlorine gas exposure. The initial treatment involves emergent decontamination. Be on the lookout for liquid chlorine on the patient’s clothes and remove it if at all possible. Supportive care is the mainstay of treatment. Bronchodilators and humidified oxygen are crucial. There is some suggestion that steroids may be beneficial. Nebulized lidocaine can help with analgesia. Nebulized sodium bicarbonate should also be considered. It acts to neutralize the hydrochloric acid that forms when chlorine gas is inhaled. While the data is limited, there are several case reports suggesting a marginal improvement in PFTs and symptoms in patients who receive nebulized bicarbonate.
In general, industrial exposures are often more severe due to more concentrated exposures. It is important to realize that airway irritation can result in upper airway swelling, making intubation difficult. Therefore, be ready for cricothyrotomy in patients with severe symptoms. The recommended observation time is six hours.
Febrile Infants WITH DR. ALWAN
The incidence of serious bacterial infections (SBI) is higher in febrile neonates with reports of up to 20% in babies less than 28 days old. SBIs are divided into invasive and non-invasive and include illnesses such as urinary tract infections, bacteremia, pneumonia, meningitis, and cellulitis. Gram negative bacteria are the most commonly isolated organisms. Group B strep, when isolated, is most commonly associated with meningitis. Viral infection is the most common cause of viruses in infants overall, and rhinovirus is the most common causative organism. Of note, infants who are flu positive are less likely to have a concomitant SBI (~2%).
There are numerous clinical decision rules available to evaluate febrile infants less than 60 days old. If the child is ill-appearing on arrival, these decision rules do not apply, and aggressive resuscitation and evaluation should be pursued. If the evaluation cannot be completed according to these criteria and the patient is ill-appearing, empiric antibiotics should be given. Consider antiviral coverage in addition to empiric antibiotics in patients who are ill appearing or present with seizures, rash, or encephalitis. If the patient is well-appearing, antibiotics may be held pending further workup.
At CCHMC, the step-by-step criteria is utilized. In patients less than 28 days with a fever, a full septic workup including a lumbar puncture (LP) should be performed. In babies 28-60 days, obtain a urinalysis, blood culture, CBC, CRP, and procalcitonin. An LP can be omitted only if the patient is low risk. Empiric antibiotic coverage should include ampicillin and cefotaxime +/- acyclovir in patients 0-28 days, cefotaxime or ceftriaxone alone can be used in patients 28-60 days.
Dispatch-assisted CPR WITH DR. Zozula
Access to emergency services via 911 is ever expanding. Text to 911 is available in some areas which is particularly useful in situations where a call is not feasible. In some rural areas, the 911 operator may have minimal, if any, medical training. In general, however, there has been a push for standardization to the advice given over the phone.
The Medical Priority Dispatch System (MPDS) is a system used to determine appropriate aid based on medical complaints and is what is used in southeast Ohio. The goal is that based on the chief complaint given by the caller, the operator can choose an appropriate protocol to approach the situation. The operator asks specific questions to determine the priority of the call, A through E or O (referral to another service). Emergency medical services (EMS) resources are then dispatched according to the designation, with A signaling BLS generally, and D mandating ALS transports.
Dispatch is able to provide instructions on CPR administration to callers. One study found that out-of hospital cardiac arrests had bystander CPR rates of 14.9% prior to the 911 call. Once 911 was contacted, CPR was started on 74% of the remaining arrests.1 Unsurprisingly, survival rates improved with early CPR and dispatch-assisted CPR. One up-and-coming way to improve early CPR rates in out-of-hospital cardiac arrest is to crowd source CPR. There are mobile-phone applications that can dispatch people to the scene of cardiac arrest patients. One study found that 23% of volunteers beat EMS to the scene when dispatched using this app.2 PulsePoint is an example of this in the United States. The goal is to get someone to the scene of an arrest as quickly as possible and instruct them on how to perform CPR until additional help can arrive. Ultimately, we all know that early CPR can help improve meaningful survival, and we should strive to minimize time to CPR in the out-of-hospital cardiac arrest patient.
Shah M., Bartram C., Irwin K., Vellano K., et al. Evaluating dispatch-assisted CPR uring the CARES registry. Prehosp Emerg Care, 2018; 22(2): 222-228.
Ringh M., Rosenqvist M., Hollenberg A., Jonsson M., et al. Mobile-phone dispatch of laypersons for CPR in out-of-hospital cardiac arrest. New England Journal of Medicine, 2015; 372: 2316-2325.