Q: Can you use high flow nasal cannula (HFNC) to manage acute hypercapnic respiratory failure?
A: It probably depends.
Background: While we now frequently utilize HFNC as an initial therapy for most acute hypoxic respiratory failure, its appropriateness in managing acute respiratory failure with hypercarbia has historically been opposed. With more recent data indicating that HFNC may be as good as noninvasive ventilation (NIV) for management of hypercapnia as well, this seemed like a good time to point out a few things:
The RENOVATE trial was a larger multicenter randomized noninferiority trial looking at HFNC vs NIV in all-comer acute respiratory failure, summarizing that HFNC was noninferior in the primary composite outcome of death + intubation at 7 days.
BUT this conclusion is not clearly supported in the smaller COPD (or acute cardiogenic pulmonary edema) subgroup:
What does seem to be clear across studies that HFNC has the capacity to clear some CO2 and is by and large better tolerated than facemask NIV.
Bottom Line: For mild-moderate acute COPD exacerbations with patient intolerance or exclusion criteria for NIV therapy, trialing HFNC is a reasonable option. For patients with severe acute or acute on chronic hypercapnia, as indicated by a [pseudo-arbitrary] pH < 7.25 and PaCO2 >70-80, noninvasive ventilation should be your go-to… or be ready to promptly intubate if/when the high flow fails.
A recent systematic review compared the timing and diagnostic accuracy of manual pulse check versus point-of-care ultrasound (POCUS) pulse checks (this means placing an ultrasound probe on the carotid or femoral artery to evaluate for a doppler pulse).
The review included seven studies encompassing a total of 469 patients.
Six of the studies assessed the duration of pulse checks, revealing a mean time difference of –1.39 seconds (95% CI: –2.20 to –0.57) in favor of ultrasound.
Three of the studies reported the sensitivity and specificity of POCUS pulse checks, yielding pooled estimates of 99% sensitivity (95% CI: 87%–100%) and 96% specificity (95% CI: 85%–99%). In contrast, two studies evaluated manual pulse checks, with pooled sensitivity of 62% (95% CI: 22%–91%) and specificity of 91% (95% CI: 88%–93%).
As with many systematic reviews, the studies included demonstrated high heterogeneity and generally low methodological quality, indicating that further investigation may still be needed.
This paper reminds us older patients have higher mortality and worse outcomes overall if their injury includes a head injury. Any mechanism that results in head injury, including fall from standing, has a higher potential for death, disability, and long term cognitive decline in older patients. Triaging these patients to trauma centers can lead to better outcomes. The difficulty is knowing which patients to send to trauma centers vs. emergency departments. The authors write:
"clinicians should consider transporting to a trauma center in geriatric patients with head trauma, if feasible. However, given the frequency with which head injury occurs, transportation to a trauma center for all patients with head trauma is likely to overwhelm EMS systems and hospitals. Unfortunately, the existing literature does not delineate the subset of patients whose condition will benefit from this evaluation . Given these considerations, we recommend EMS clinicians consider abnormal mental status, presence of anti-coagulation, and loss of consciousness as considerations to transport to a trauma center in cases where the need for trauma center evaluation is not clear.”
Reenforcing the recent pearl on geriatric trauma patient care, here is the National Association EMS Physicians statement on prehospital care.
"EMS clinicians should use age-adjusted, physiologic criteria to guide decisions to transport geriatric trauma patients to the most appropriate level of trauma center available in the community.
Geriatric trauma patients should be promptly evaluated for pain and should receive analgesic interventions in a timely manner. Analgesic medications should be dosed following weight-based guidance and should be administered with consideration of potential drug interactions and age-related changes in drug metabolism and side effects.
EMS clinicians should consult advance care planning documents, e.g., Physician Orders for Life-Sustaining Treatment (POLST), when available, to guide care in emergency scenarios, including management of traumatic injuries.
While older patients are at higher risk for spinal injuries, including lumbar and cervical spine fractures, traditional spinal motion restriction practices may not be suitable for older patients due to age-related anatomic changes in spinal alignment and increased risk for cutaneous pressure-related injuries. EMS clinicians should exercise judgment to determine when and how to best achieve spinal motion restriction if spinal injury is suspected in geriatric trauma patients."
In the pediatric ED, intranasal midazolam is a common choice among providers for procedural sedation. However, with widely varying recommendations, the ideal dose remains a topic of debate.
A recent randomized clinical trial published in JAMA Pediatrics involving 101 children, ages 6 months to 7 years, sought to determine the best dose of intranasal (IN) midazolam for sedation during laceration repair. Researchers compared four different doses: 0.2, 0.3, 0.4, and 0.5 mg/kg.
The primary outcome was achieving adequate sedation for at least 95% of the procedure. Secondary outcomes included the level of sedation, how quickly it took effect, recovery time, satisfaction of clinicians and caregivers, and any negative side effects.
What did they find?
The lower doses (0.2 and 0.3 mg/kg) were found to be less effective and were removed from the study early.
The two higher doses (0.4 and 0.5 mg/kg) both provided similar, adequate sedation for about two-thirds of the children.
Sedation took effect quickly, within a few minutes, and children recovered fast.
Adverse events were rare and not serious.
Satisfaction among both clinicians and caregivers was high across the board.
Bottom line: Consider reaching for higher doses of intranasal midazolam (0.4 to 0.5 mg/kg) for pediatric patients requiring procedural sedation.
This retrospective study looking at a readmission database for patients greater than 65 years categorized 10,000 patients into non-frail, pre-frail and frail based on the five-factor modified frailty index. They found no difference in recurrent diverticulitis among the groups but did find:
“frailty was a predictor of mortality on index hospitalization (adjusted odds ratio, 1.99; p < 0.001) and readmissions (adjusted odds ratio, 3.05; p < 0.001)…frail patients are at increased risk of mortality once they develop diverticulitis. Optimal management for frail patients with diverticulitis must be defined to improve outcomes.”
Once again, assessing your patient's frailty can help you predict outcomes and have meaningful discussions with patients and their families.
Settings: multinational, randomized, double- blind, placebo-controlled clinical trial conducted in 17 centers in Italy, Russia, and Kazakhstan
Participants: A total of 307 ICU patients with sepsis or septic shock. Patients who were likely to die (APACHE II > 65 points) were excluded.
Treatment group: 80 mg bolus of omeprazole at randomization, at 12 hours and infusion of 12 mg/hour for 72 hours. Total dose of 1024 mg.
Outcome measurement: primary outcome of the study was organ dysfunction measured as the mean daily SOFA score during the first 10 days. Secondary outcomes were antibiotics-free days at 28 days; all-cause mortality at 28 days
Study Results:
Discussion:
Conclusion:
In sepsis patients, Esomeprazole did not re- duce organ dysfunction, despite demonstrating in vivo immunomodulatory effects
Carbon Monoxide Poisoning (COP) is a major toxicologic pathology and a common case in the Emergency Department and pre-hospital setting. History is a key component in assessment with the standard diagnostic test being blood gas analysis of Carboxyhemoglobin (COHb).
Standard pulse oximeter devices are not capable of differentiating oxyhemoglobin from carboxyhemoglobin, leading to the classic pearl that pulse ox may be falsely reassuring in COP.
In recent years, devices capable of differentiating oxyhemoglobin from COHb have been developed and are fielded in many hospitals and EMS agencies.
This meta-analysis reviews diagnostic accuracy of pulse CO-oximetry (spCO) devices in comparison to a reference standard COHb blood test. Six studies (1734 patients) were included.
This analysis found that spCO testing has a low sensitivity and high specificity.
Pooled sensitivity 0.65 (95% CI 0.44–0.81)
Pooled specificity 0.93 (95% CI 0.83–0.98)
Pooled LR+ 9.4 (95% CI 4.4 to 20.1)
Pooled LR- 0.38 (95% CI 0.24 to 0.62)
The authors conclude that the low sensitivity precludes use of spCO as an effective screening tool for COP or substitute for COHb. Conversely, we can recognize the utility of the high specificity in identifying patients who do have clinically significant toxicity. Indeed, the authors discuss potential applications for triage and transport to a hyperbaric oxygen chamber for those who are found to have elevated readings.
Technology advancement and refinement will be interesting to follow. In the meantime, don’t skip the COHb lab just because spCO measurement is reassuring.
This review article reminds us that abdominal hypertension and compartment syndrome need to remain on our differential diagnosis for critically ill and injured patients. Pressure is measured with an intra-bladder catheter. Normal pressure is 5-7 mm HG. Sustained over 12 mm Hg is hypertension and sustained over 20 mm Hg is compartment syndrome.
Use of Muscle Relaxants in the Elderly
A 2023 Cochrane Database review found moderate-certainty evidence that muscle relaxants may increase the risk of adverse events.
Primary adverse events are due to CNS depressant effects (dizziness, sedation) and anticholinergic effects.
Geriatric patients already have baseline unsteady gait, decreased coordination and cognitive changes.
A 2015 study showed that geriatric patients who took muscle relaxants were 2.25 times more likely to visit the ED for a fall or fracture and 1.5 times more likely to be hospitalized for a fall or fracture than patients who did not take these medications.
Risk is greatest in patients >65 years of age. This population was 1.32 times more likely to have an injury compared to patients who did not take skeletal muscle relaxants.
This study looking at pre and post-phenobarbital order set use to treat inpatient alcohol withdrawal syndrome found:
“AWS symptoms resolved more rapidly after implementation, with a 4.2- to 5.0-point reduction in daily maximum CIWA-Ar scores at 24 to 96 hours from hospital presentation, 30.1-hour reduction in AWS treatment duration (95% CI, 16.7-43.5 hours), and 2.2-day reduction in time to hospital discharge (95% CI, 0.7-3.7 days). Safety outcomes did not significantly differ before and after implementation.”
Remember phenobarbital can be used for alcohol withdrawal for our ED patients as well.
Here is the protocol:
Nursing
Vital signs 10 minutes after phenobarbital loading dose
Clinical Institute Withdrawal Assessment for Alcohol Revised (CIWA-Ar) every 1-4 hours based on score
Loading Dose
Phenobarbital 15 mg/kg intravenous piggyback (recommended for most patients)
Phenobarbital 10 mg/kg intravenous piggyback (low risk or heavily pretreated with benzodiazepines)
As-Needed Doses
Phenobarbital 130 mg intravenous twice as needed for uncontrolled agitation or CIWA-Ar ?15
Phenobarbital 260 mg intravenous once as needed for uncontrolled agitation or CIWA-Ar ?15
This publication is a retrospective cross-sectional study conducted based on data collected during January 1–December 31, 2019 from a large, academic ED in the Southeastern US with the following research questions and results:
Interesting point regarding how disposition decisions are different from the ample evidence on disparities within triage decisions: The presence of disparities in disposition decisions is noteworthy not only because of their potentially long-term effects on patients’ health, but also because unlike some of the other decisions made in the ED such as triage, they are typically made under relatively less time pressure with deliberation and input from multiple individuals, conditions that are known to make biases less likely.
Authors propose pursing further research to elucidate the factors that contribute to these findings, instituting systems to alert providers in real time to the presence of conditions that could exacerbate disparities in ED care, and including the measurement of disparities along sex, race and ethnicity into health care operations data.
This systematic review of the literature found four findings associated with intercranial hemorrhage in older patients after a fall. They were: focal neurologic findings, external signs of trauma on the head, loss of consciousness, and male sex.
We still need better studies as this is completely based on the quantity and quality of literature available to review. This information is not enough to change liberal CT imagining in older patients after a fall. It is the beginning of the study process.
Systemic racism and institutional bias affect all aspects of medicine. This position paper from 2022 highlights some of the disparities present within the EM Clinical Ultrasound community. The authors identified several areas of concern regarding the make up of the leadership of the CU community, and importantly suggest several ways to create a more equitable specialty.
This was a European study examining a screening tool to be used in the ED to indicate the need for further investigation into the concern for possible abuse. Four questions were taken from other commonly used abuse screening tools that were used outside of the ED. SCAN questions are as follows:
Is the injury compatible with the history, and does it correspond to the child's developmental level?
Was there an unnecessary delay in seeking medical help?
Is the behavior/interaction of the child and caregivers appropriate?
Are there other signals that make you doubt the safety of the child or family?
Any positive answer triggered further evaluation, starting with a complete head to toe assessment and complete history with additional tests added as warranted. This is only a screening tool and positive answers do NOT mean that abuse has occurred, but should cause you to pause and think further.
These questions showed a "moderate" performance among close to 25000 patients and the questions were comparable in children < 5 years to other/longer screening tools used in Europe.
There is no standardized prehospital neonatal resuscitation curriculum for EMS. The Neonatal Resuscitation Program (NRP) guidelines focus on hospital based births which may not translate to the prehospital environment.
This study was prospective and observational that used a virtual, EMS tailored newborn resuscitation curriculum. Initially, 350 EMS clinicians watched a 90 min video. This was then modified based on their feedback to a 60 minute interactive curriculum specifically designed for EMS that emphasized NRP concepts and reinforced how NRP was different from pediatric resuscitation. 17 EMS jurisdictions viewed the program and were then given a brief NRP based quiz before, after and 3 months following the training.
Feedback was overall positive and post test and 3 month follow up test scores showed improvement from the pre test scores.
Standardized neonatal resuscitation education represents an area where improvements can be made in prehospital education. This particular curriculum was well received and improved EMS clinicians knowledge based. Jurisdictional medical directors should work with their department on standardized education for the neonatal population.
Also, stay tuned for updated NRP guidelines which are due to come out this fall.
The National Association of EMS Physicians, the American College of Surgeons Committee on Trauma, and the American College of Emergency Physicians recommends:
• Prehospital TXA administration may reduce mortality in adult trauma patients with hemorrhagic shock when administered after lifesaving interventions.
• Prehospital TXA administration appears safe, with low risk of thromboembolic events or seizure.
• The ideal dose, rate, and route of prehospital administration of TXA for adult trauma patients with hemorrhagic shock has not been determined. Current evidence suggests EMS agencies may administer either a 1-g intravenous/intraosseous dose (followed by a hospital-based 1-g infusion over 8 hours) or a 2-g intravenous/intraosseous dose as an infusion or slow push.
• Prehospital TXA administration, if used for adult trauma patients, should be given to those with clinical signs of hemorrhagic shock and no later than 3 hours post-injury. There is no evidence to date to suggest improved clinical outcomes from TXA initiation beyond this time or in those without clinically significant bleeding.
• The role of prehospital TXA in pediatric trauma patients with clinical signs of hemorrhagic shock has not been studied, and standardized dosing has not been established. If used, it should be given within 3 hours of injury.
• Prehospital TXA administration, if used, should be clearly communicated to receiving health care professionals to promote appropriate monitoring and to avoid duplicate administration(s).
• A multidisciplinary team, led by EMS physicians, that includes EMS clinicians, emergency physicians, and trauma surgeons should be responsible for developing a quality improvement program to assess prehospital TXA administration for protocol compliance and identification of clinical complications.
Epidural abscess
Likely the most serious missed emergent condition in patients diagnosed with non-specific back pain.
Challenging diagnosis to make in the ED
Almost half of patients are initially misdiagnosed and average two ED visits before the diagnosis is made.
At the time of diagnosis, the most common symptom is diffuse spine pain and the most common exam finding is severe local spinal tenderness.
Fever is only present in 30% to 50% of patients at presentation.
In one study, over 65% of patients with spinal epidural abscesses were afebrile on presentation.
Also, consider that the neurological examination is normal in two-thirds of patients at their first ED visit.
Background:
Several trials have explored the use of IV thrombolysis before endovascular thrombectomy (EVT) in ischemic stroke patients, and a pooled analysis from these trials showed no significant difference in efficacy between intravenous thrombolysis plus EVT compared to EVT alone. However, only 2.2% of patients in the trials included in this pooled analysis received tenecteplase (TNK), with the vast majority of patients receiving alteplase. (1) While a 2018 trial showed improved early reperfusion and 90-day outcomes with TNK compared to alteplase before EVT, a recent target trial emulation analysis indicated no added benefit with TNK plus EVT over EVT alone. (2-3) Lack of comparison between TNK plus EVT versus EVT alone and small sample sizes of prior trials led to the design of the BRIDGE-TNK trial, which directly compared TNK plus EVT versus EVT alone in acute ischemic stroke. (4)
Study design:
This multi-center, randomized, open-label trial conducted at 39 hospitals in China included patients with large-vessel occlusion (LVO) of the internal carotid, middle cerebral or basilar artery on CTA or MRA imaging who presented within 4.5 hours of their last known well time, and were eligible to undergo intravenous thrombolysis and EVT.
Exclusion criteria were intracranial hemorrhage on CT or MRI imaging, rapidly improving symptoms at the discretion of the investigator, pre-stroke modified Rankin scale (mRS) of > 4, contraindication to imaging with contrast agents, patients who needed interhospital transfer before thrombectomy, any terminal illness such that the patient would not be expected to survive more than 1 year, any condition that could impost hazards to the patient if study therapy is initiated in the judgement of the investigator, hypodensity in >1/3 of middle cerebral artery or basilar artery territory on non-contrast CT, and pregnant women.
The primary outcome was functional independence at 90 days, defined as an mRS score of 0 to 2.
Patient Population:
Baseline characteristics were well matched between treatment arms:
Results:
Primary outcome:
Secondary outcomes:
Study Limitations:
Key Takeaways:
While rates of symptomatic intracranial hemorrhage and mortality were higher in the TNK + EVT group, neither of these outcomes met statistical significance and bridging with TNK prior to EVT led to increased rates of functional independence at 90 days compared to EVT alone. The findings of this study reinforce current guideline recommendations for not skipping intravenous thrombolysis prior to thrombectomy for LVO stroke.
The TLDR:
In the ED setting, CTA for suspected GI bleeding is frequently ordered, but it’s finding less. At one center, use went up sevenfold over six years, while positive results dropped from 1 in 5 scans to about 1 in 16. Older patients are more likely to have a positive scan, and those with active cancer less so. CTA can be very useful when targeted, but widespread use may add cost, radiation, and crowding without improving care—so choosing patients carefully is key.
The longer version:
This was a retrospective cohort study involving adult patients who had undergone abdominal and pelvic CTA for suspected GIB at a large urban academic medical center between January 2017 and December 2023. The primary outcomes of interest were 1) The annual number and proportion of GIB-related CTAs among all CT scans performed in the ED, and 2) The diagnostic yield, defined as the percentage of CTAs that showed active bleeding or hemorrhage.
Findings:
CTA usage increased substantially: In 2017, there were 30 GIB-related CTAs out of 32,197 ED CT exams (0.09%). By 2023, this rose to 288 out of 44,423 (0.65%)
Diagnostic yield declined: In 2017, 6 of 30 CTAs were positive (20.0%). In 2023, only 18 of 288 were positive (6.3%)
Data of interest:
Later years (ie 2023 rather than 2017) were linked to lower odds of a positive CTA (odds ratio [OR] 0.84 per year; 95% CI, 0.73–0.96; P = .01). Older patients had higher odds of a positive result (OR 1.02 per year of age; 95% CI, 1.00–1.04; P = .02). Patients with active cancer had lower odds of positive findings (OR 0.35; 95% CI, 0.12–1.00; P = .05)
Discussion:
Despite the marked increase in CTA use for suspected GIB, its diagnostic effectiveness dropped sharply over the study period. The findings emphasize the need to balance the benefits (such as detecting active bleeding) with the downsides—including interpretation time, radiation exposure, costs, and ED crowding. The authors suggest implementing evidence-based protocols and decision-support tools to optimize CTA use in emergency settings to improve appropriateness and diagnostic yield.
