RUSHing to the Diagnosis: Aortic Abdominal Aneurysm Detected Using the Rapid Ultrasound for Shock and Hypotension (RUSH) Protocol in the Wards.

The rapid ultrasound for shock and hypotension (RUSH) protocol is a useful tool used in the emergency department (ED) when addressing the severity and etiology of shock. It was designed to be performed in under two minutes with evaluation of the pump (heart), tank (inferior vena cava, thoracic and abdominal compartments) and the pipes (large arteries and veins). However, its application or one similar should extend beyond the ED and into the hospital floor. Here we present an 80-year-old gentleman with a history of atrial fibrillation (A-Fib) on anticoagulation who arrived at the ED due to an episode of pre-syncope just prior to arrival. Initial EKG is concerning for A-Fib with rapid ventricular response (RVR) with a rate in the 130s. After fluid resuscitation patient improved and he was admitted to the telemetry floor for further cardiac workup and cardiology consultation. While waiting for a room in the ED, patient became hypotensive, diaphoretic and pale. After complaining of lower abdominal pain, the ED physician performed a RUSH which showed an abdominal aorta of 8 cm concerning for dissection. Diagnosis was confirmed with CT angiography of the abdomen and he was taken to the OR with successful repair of the abdominal aortic aneurysm (AAA). Patient made meaningful recovery and was discharged to in-patient rehab. The patient described in this vignette was delayed in the ED due to lack of beds on the floor. This allowed for quick ultrasound work-up by the ED physician which led to immediate recognition of the AAA and immediate response by the vascular surgery team. Should this patient have been on the hospital floor, it is unclear if such prompt steps would have occurred prior to patient's further hemodynamic demise.

Acute Hypersensitivity Reaction After Casirivimab/Imdevimab Infusion in a COVID-19-Positive Young Male: Myopericarditis or Kounis Syndrome?

Myocarditis has been a rare, but well-documented side effect of the mRNA-based vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as well as a complication of viral infections including SARS-CoV-2. However, myopericarditis as a complication of monoclonal antibody infusion or as a complication of allergic reaction to antibody infusions might be underreported. We report the case of a 30-year-old man with a previous diagnosis of coronavirus disease 2019 (COVID-19) infection one week prior to presentation, unvaccinated for SARS-CoV-2, who was referred from a monoclonal infusion center where he received casirivimab/imdevimab and 15 minutes after the infusion began to complain of chills, chest pain, shortness of breath, and was hypotensive. In the infusion center, the patient received epinephrine and diphenhydramine and was directed to the ER, where the patient was febrile, tachycardic, and hypotensive. Initial troponin was 1.91 which peaked at 11.73 and CK-MB which peaked at 21.2. EKG had no ischemic changes. A two-dimensional echocardiogram showed an ejection fraction (EF) of about 45%, with a left ventricular dysfunction and trivial posterior pericardial effusion, and it was diagnosed as myopericarditis. On admission, he was started on full-dose enoxaparin, aspirin, fluid resuscitation, steroids, remdesevir, and bilevel positive airway pressure (BiPap) due to his respiratory compromise. Three days later, with clinical improvement, a repeat echocardiogram showed EF of 65%, with normal ventricular contractility and no pericardial effusion. The patient was discharged home with close cardiology follow-up. Though this could be a simple case of viral myopericarditis with troponinemia secondary to demand-ischemia, the differential should be broadened to complication of monoclonal antibody, given the sudden symptom onset after infusion completion and/or a possible Kounis syndrome. Though there have not been any reported cases of casirivimab/imdevimab causing myopericarditis, adverse cardiac events after monoclonal therapy have been reported mainly in cancer patients receiving monoclonal infusions.

The Importance of Radiologic Imaging Modalities in Autosomal Dominant Polycystic Kidney Disease.

Autosomal dominant polycystic kidney disease (ADPKD) is a common disorder that occurs in approximately one in 1000 live births. Patients may be asymptomatic or present with symptoms such as hypertension, hematuria, proteinuria, or renal function impairment. It can present with extra renal complications like cerebral aneurysms, hepatic and pancreatic cysts, infected cysts, cardiac valve disease, colonic diverticula, abdominal wall and inguinal hernia, and seminal vesicle cyst. Imaging studies such as ultrasonography (US), computed tomography (CT), and magnetic resonance imaging (MRI) provide vital information regarding the diagnosis of the disease, monitoring of the progression of the disease, and detection of complications from the disease. We present the case of a 40-year-old male who developed extra-renal complications, and how different imaging modalities facilitated and enabled us to optimize the care of this patient in a timely manner.

Bitten to the Bone: A Case of Anxiety-Induced Osteomyelitis.

Onychophagia is a habitual nail-biting disorder, usually associated with mental or emotional diseases. It affects 20-30% of the population in all age groups. Human bites have the potential to become serious injuries due to high virulence in the human oral flora and may often require hospital admission, antibiotics and even debridement in the operating room. Thus, repetitive nail biting has the potential to be limb-threatening if not treated early and appropriately. We present a 49-year-old Spanish-speaking gentleman, with a past medical history of repetitive nail biting secondary to severe anxiety, major depression disorder, bilateral hand neuropathy secondary to diabetes mellitus (DM) type 2 who was initially admitted to the hospital due to cellulitis of the fingers with suspected osteomyelitis in the right hand. Anxiety was being treated by psychiatrist with paroxetine however, given no improvement and prolonged follow-ups, the primary care physician (PCP) added hydroxyzine and scheduled alprazolam in an attempt to minimize symptoms. Despite these efforts, patient continued with nail biting. On initial physical exam, the patient had a lack of fingernails and multiple wounds at various stages of healing across all digits. The distal and middle phalanges of the third right digit showed increased erythema and swelling and band tightening. Patient was started on broad-spectrum antibiotics. Initial radiography of the right hand was concerning for osteomyelitis which was later confirmed with Magnetic Resonance Imaging (MRI). Infectious disease specialist agreed on a course of cefepime, vancomycin and metronidazole. On admission, hand surgeon did not see a need for amputation and patient was treated conservatively. Due to minimal improvement after six days on IV antibiotics, patient underwent fasciotomy of the flexor compartment of the right middle finger after patient rejected hand surgeon's recommendation for amputation. He was discharged to a skilled nursing facility where he was to continue intravenous antibiotics for an additional four weeks. The vulnerable patient population of South Texas is predominately Hispanic, Spanish-speaking and uninsured. It is imperative to treat psychiatric disorders early to prevent complications, however, given the low numbers of psychiatrists in the Rio Grande Valley and even fewer who speak Spanish it is not unusual to find an appointment in more than six months. In this case, we observe how a trivial everyday behavior can lead to limb-threatening complications if not treated early and appropriately.

Double-blind, Randomized, Placebo-controlled Study Evaluating the Use of Platelet-rich Plasma Therapy (PRP) for Acute Ankle Sprains in the Emergency Department.

BACKGROUND: Over 23,000 people per day require treatment for ankle sprains. Platelet-rich plasma (PRP) is an autologous concentration of platelets that is thought to improve healing by promoting inflammation through growth factor and cytokine release. Studies to date have shown mixed results, with few randomized trials. OBJECTIVES: To determine patient function among patients randomized to receive standard therapy plus PRP, compared to patients who receive standard therapy plus sham injection (placebo). METHODS: Prospective, randomized, double-blinded, placebo-controlled trial. Patients with severe ankle sprains were randomized. Severity was graded on degree of swelling, ecchymosis, and ability to bear weight. PRP with lidocaine and bupivacaine was injected at the point of maximum tenderness by a blinded physician under ultrasound guidance. The control group was injected in a similar fashion with sterile 0.9% saline. Both groups had visual analog scale (VAS) pain scores and Lower Extremity Functional Scale (LEFS) on days 0, 3, and 8. LEFS and a numeric pain score were obtained via phone call on day 30. All participants were splinted, given crutches, and instructed to not bear weight for 3 days; at this time patients were reevaluated. RESULTS: There were 1156 patients screened and 37 were enrolled. Four withdrew before PRP injection was complete; 18 were randomized to PRP and 15 to placebo. There was no statistically significant difference in VAS and LEFS scores between groups. CONCLUSION: In this small study, PRP did not provide benefit in either pain control or function over placebo.

Phencyclidine Intoxication Case Series Study.

BACKGROUND: Phencyclidine (PCP) is a synthetic compound derived from piperidine and used as an anesthetic and hallucinogenic. Little has been recently published regarding the clinical presentation of PCP intoxication. PCP use as a recreational drug is resurging. OBJECTIVE: Our objective was to describe clinical findings in patients presenting to the emergency department (ED) under the influence of PCP. METHODS: This was a case series study conducted at a tertiary care center with an annual census of 100,000 patients/year. Emergency physicians, residents, physician assistants, and research assistants identified patients with possible PCP intoxication. Self-reported PCP use, report by bystanders or Emergency Medical Services (EMS) staff, was used in this process. A structured data collection form was completed, documenting both clinical and behavioral events observed by the treating team during the ED visit. RESULTS: We collected data on 219 patients; 184 were analyzed; two patients were excluded secondary to incomplete data. The mean age of patients was 32.5 years (±7 years) with 65.2 % being males. PCP use was self-reported by 60.3 % of patients. Of the 184 patients, 153 (83.1 %) received a urine drug screen (UDS); 152 (98.7 %) were positive for PCP. On arrival, 78.3 % of patients were awake and alert, and 51.6 % were oriented to self, time/date, and place. Mean physiological parameters were the following: heart rate 101.1 bpm (±24.3), RR 18.9 bpm (±3.4), BP 146.3 (±19.4)/86.3 (±14.0) mmHg, 36.9° C (±0.5), and pulse oximetry 98.2 % (±1.9). Clinical findings were the following: retrograde amnesia in 46 (25 %), horizontal nystagmus in 118 (64.1 %), vertical nystagmus in 90 (48.9 %), hypertension in 87 (47.3 %), and agitation in 71 (38.6 %). Concomitant use of at least one other substance was reported by 99 (53.8 %) patients. The mean length of stay in the ED for all subjects was 261.1 (±172.8) minutes. Final disposition for 152 (82.6 %) patients was to home. Of the 184 patients, 14 (7.6 %) required admission; 12 were referred to Crisis Response Center. CONCLUSION: Patients with PCP intoxication tended to be young males. The prevalent clinical signs and symptoms were the following: retrograde amnesia, nystagmus, hypertension, and psychomotor agitation. Co-use of other substances was the norm. Most patients presenting to the ED with PCP intoxication do well and can be discharged home after a period of observation.

The utility of high-flow oxygen during emergency department procedural sedation and analgesia with propofol: a randomized, controlled trial.

STUDY OBJECTIVE: We determine whether high-flow oxygen reduces the incidence of hypoxia by 20% in adults receiving propofol for emergency department (ED) sedation compared with room air. METHODS: We randomized adults to receive 100% oxygen or compressed air at 15 L/minute by nonrebreather mask for 5 minutes before and during propofol procedural sedation. We administered 1.0 mg/kg of propofol, followed by 0.5 mg/kg boluses until the patient was adequately sedated. Physicians and patients were blinded to the gas used. Hypoxia was defined a priori as an oxygen saturation less than 93%; respiratory depression was defined as an end tidal CO(2) greater than 50 mm Hg, a 10% absolute change from baseline, or loss of waveform. RESULTS: We noted significantly less hypoxia in the 59 patients receiving high-flow oxygen compared with the 58 receiving compressed air (19% versus 41%; P=.007; difference 23%; 95% confidence interval 6% to 38%). Respiratory depression was similar between groups (51% versus 48%; difference 2%; 95% confidence interval -15% to 22%). We observed 2 adverse events in the high-flow group (1 hypotension, 1 bradycardia) and 2 in the compressed air group (1 assisted ventilation, 1 hypotension). CONCLUSION: High-flow oxygen reduces the frequency of hypoxia during ED propofol sedation in adults.

Two days of dexamethasone versus 5 days of prednisone in the treatment of acute asthma: a randomized controlled trial.

STUDY OBJECTIVE: Dexamethasone has a longer half-life than prednisone and is well tolerated orally. We compare the time needed to return to normal activity and the frequency of relapse after acute exacerbation in adults receiving either 5 days of prednisone or 2 days of dexamethasone. METHODS: We randomized adult emergency department patients (aged 18 to 45 years) with acute exacerbations of asthma (peak expiratory flow rate less than 80% of ideal) to receive either 50 mg of daily oral prednisone for 5 days or 16 mg of daily oral dexamethasone for 2 days. Outcomes were assessed by telephone follow-up. RESULTS: Ninety-six prednisone and 104 dexamethasone subjects completed the study regimen and follow-up. More patients in the dexamethasone group reported a return to normal activities within 3 days compared with the prednisone group (90% versus 80%; difference 10%; 95% confidence interval 0% to 20%; P=.049). Relapse was similar between groups (13% versus 11%; difference 2%; 95% confidence interval -7% to 11%, P=.67). CONCLUSION: In acute exacerbations of asthma in adults, 2 days of oral dexamethasone is at least as effective as 5 days of oral prednisone in returning patients to their normal level of activity and preventing relapse.

Does end tidal CO2 monitoring during emergency department procedural sedation and analgesia with propofol decrease the incidence of hypoxic events? A randomized, controlled trial.

STUDY OBJECTIVE: We determine whether the use of capnography is associated with a decreased incidence of hypoxic events than standard monitoring alone during emergency department (ED) sedation with propofol. METHODS: Adults underwent ED propofol sedation with standard monitoring (pulse oximetry, cardiac and blood pressure) and capnography and were randomized into a group in which treating physicians had access to the capnography and a blinded group in which they did not. All patients received supplemental oxygen (3 L/minute) and opioids greater than 30 minutes before. Propofol was dosed at 1.0 mg/kg, followed by 0.5 mg/kg as needed. Capnographic and SpO2 data were recorded electronically every 5 seconds. Hypoxia was defined as SpO2 less than 93%; respiratory depression, as end tidal CO2 (ETCO2) greater than 50 mm Hg, ETCO2 change from baseline of 10%, or loss of the waveform. RESULTS: One hundred thirty-two subjects were evaluated and included in the final analysis. We observed hypoxia in 17 of 68 (25%) subjects with capnography and 27 of 64 (42%) with blinded capnography (P=.035; difference 17%; 95% confidence interval 1.3% to 33%). Capnography identified all cases of hypoxia before onset (sensitivity 100%; specificity 64%), with the median time from capnographic evidence of respiratory depression to hypoxia 60 seconds (range 5 to 240 seconds). CONCLUSION: In adults receiving ED propofol sedation, the addition of capnography to standard monitoring reduced hypoxia and provided advance warning for all hypoxic events.

Routine packing of simple cutaneous abscesses is painful and probably unnecessary.

OBJECTIVES: The objective was to determine whether the routine packing of simple cutaneous abscesses after incision and drainage (I&D) confers any benefit over I&D alone. METHODS: In a prospective, randomized, single-blinded trial, subjects with simple cutaneous abscesses (less than 5 cm largest diameter) underwent incision, drainage, irrigation, and standard abscess preparation in the usual manner. Subjects were then randomized to either packing or no-packing. Visual analog scales (VAS; 100 mm) of pain were recorded in the emergency department (ED). All patients received trimethoprim-sulfamethoxazole (TMP-SMX), ibuprofen, and narcotic prescriptions, recorded twice daily VAS pain scores, and returned in 48 hours at which time dressings and packing, if present, were removed and a physician blinded to the randomization and not part of the initial visit repeated measurements and determined the need for further intervention. RESULTS: Forty-eight subjects were included in the final analysis. There were no significant differences in age, sex, abscess location, or initial pain scores between the two groups. There was no significant difference in need for a second intervention at the 48-hour follow-up between the packed (4 of 23 subjects) and nonpacked (5 of 25 subjects) groups (p = 0.72; relative risk = 1.3, 95% confidence interval [CI] = 0.4 to 4.2). Patients in the group that received packing reported higher pain scores immediately postprocedure (mean difference = 23.8 mm; p = 0.014, 95% CI = 5 to 42 mm) and at 48 hours postprocedure (mean difference = 16.4 mm; p = 0.03, 95% CI = 1.6 to 31.2 mm), as well as greater use of ibuprofen (mean difference = 0.32; p = 0.12, 95% CI = -1.4 to 2.0) and oxycodone/acetaminophen (mean difference = 2.19; p = 0.03, 95% CI = 0.2 to 4.1). CONCLUSION: In this pilot study, not packing simple cutaneous abscesses did not result in any increased morbidity, and patients reported less pain and used fewer pain medications than packed patients.

Eye irrigation is more comfortable with a lidocaine: containing irrigation solution compared with normal saline.

BACKGROUND: Is eye irrigation with a Morgan lens more comfortable with a lidocaine-containing solution compared with standard saline? METHODS: Prospective randomized double-blind volunteer placebo controlled study. Subjects received two drops of 2% tetracaine in each eye. Morgan lenses were applied to each eye and connected to separate 1-L bags of room temperature 0.9% saline. Subjects were randomized to continuous irrigation with 0.01% lidocaine solution (10 mL of 1% lidocaine [100 mg] in 1 L saline) in either the right or left eye with the opposite eye serving as control. pH was measured and fluid flow rate set at 35 mL/min. Blinded interviewers asked the subjects at 5 minutes intervals to rate their discomfort on a five-point Likert scale. Differences in mean Likert scores and standard deviation at 5, 10, 15, 20, and 25 minutes in each eye were calculated. Data were analyzed using one-way analysis of variance and the Bonferroni (BON) multiple comparison test (paired sample t test). RESULTS: One-way analysis of variance p value for the combined time sets was very significant (<0.0001). The difference in mean Likert scores for 5 minutes was not statistically significant; approached statistical significance at 10 minutes and were very significant at 15 minutes {1.22 [95% confidence interval (CI) 0.16-2.28]; BON 3.02}, 20 minutes [1.44 (95% CI 0.38-2.5); BON 3.57], and 25 minutes [1.55 (95% CI 0.62-2.88); BON 4.09]. There were no reported long-term adverse effects. CONCLUSIONS: Continuous irrigation of the eye with a lidocaine-saline solution and a Morgan lens causes less discomfort than saline alone in healthy volunteers.

The utility of supplemental oxygen during emergency department procedural sedation with propofol: a randomized, controlled trial.

STUDY OBJECTIVE: We determine whether supplemental oxygen reduces the incidence of hypoxia by 20% compared with breathing room air in adult study patients receiving propofol for emergency department procedural sedation. METHODS: Patients were randomized to receive either supplemental oxygen or compressed air by nasal cannula at 3 L per minute. Physicians were blinded to the gas used and end tidal CO(2) (etco(2)) data. Respiratory depression was defined a priori as oxygen saturation less than or equal to 93%, an etco(2) level of greater than or equal to 50 mm Hg, an absolute etco(2) change from baseline of greater than or equal to 10 mm Hg, or loss of the etco(2) waveform. RESULTS: Of the 110 patients analyzed, 56 received supplemental oxygen and 54 received room air. Ten (18%) patients in the supplemental oxygen group and 15 (28%) patients in the compressed air group experienced hypoxia (P=.3, effect size=10%, 95% confidence interval -24% to 7%). Twenty-seven patients (20 supplemental oxygen; 7 room air) met etco(2) criteria for respiratory depression but did not become hypoxic. Physicians identified respiratory depression in 23 of 25 patients who developed hypoxia compared with only 1 of 27 patients who met etco(2) criteria for respiratory depression but who did not have hypoxia. One patient in the supplemental oxygen group experienced a transient arrhythmia and had a short apneic episode, both of which resolved spontaneously. The patient was admitted for observation. CONCLUSION: Supplemental oxygen (3 L/minute) trended toward reducing hypoxia in adult study patients; however, the 10% difference observed was not statistically significant and was below our a priori 20% threshold. Blinded capnography frequently identified respiratory depression undetected by the treating physicians.

Comparison of octreotide and standard therapy versus standard therapy alone for the treatment of sulfonylurea-induced hypoglycemia.

STUDY OBJECTIVE: This study is designed to test the hypothesis that the administration of octreotide acetate (Sandostatin; Novartis Pharmaceuticals) in addition to standard therapy will increase serum glucose level measured at serial intervals in patients presenting to the emergency department (ED) with sulfonylurea-induced hypoglycemia compared with standard therapy alone. METHODS: This study was a prospective, double-blind, placebo-controlled trial. All adult patients who presented to the ED with hypoglycemia (serum glucose level < or = 60 mg/dL) and were found to be taking a sulfonylurea or a combination of insulin and sulfonylurea were screened for participation in the study. Study participants were randomized to receive standard treatment (1 ampule of 50% dextrose intravenously and carbohydrates orally) and placebo (1 mL of 0.9% normal saline solution subcutaneously) or standard treatment plus 1 dose of octreotide 75 microg subcutaneously. Subsequent treatment interventions were at the discretion of the inpatient internal medicine service. RESULTS: A total of 40 patients (18 placebo; 22 octreotide) were enrolled. The mean serum glucose measurement at presentation was placebo 35 mg/dL and octreotide 39 mg/dL. The mean glucose values for octreotide patients compared with placebo were consistently higher during the first 8 hours but showed no difference in subsequent hours. Mean glucose differences approached statistical significance from 1 to 3 hours and were significant from 4 to 8 hours after octreotide or placebo administration. CONCLUSION: The addition of octreotide to standard therapy in hypoglycemic patients receiving treatment with a sulfonylurea increased serum glucose values for the first 8 hours after administration in our patients. Recurrent hypoglycemic episodes occurred less frequently in patients who received octreotide compared with those who received placebo.

Immunization histories given by adult caregivers accompanying children 3-36 months to the emergency department: are their histories valid for the Haemophilus influenzae B and pneumococcal vaccines?

OBJECTIVE: To obtain immunization histories from adult caregivers accompanying children to the emergency department (ED), to determine the accuracy of the caregiver's report for the Haemophilus influenzae B (Hib)and 7-valent pneumococcal vaccine (PCV7). METHODS: This was a prospective, observational study of children age 3 to 36 months presenting to the Albert Einstein Medical Center ED during the period of November 1, 2004, through January 31, 2005. Caregivers were asked to complete a questionnaire about their child's immunization status and if the child's vaccinations were up-to-date. Immunization records were obtained from the child's most recent primary care physician (PCP) to determine whether the caregiver's report was correct for PCV7 and Hib. Children were considered delayed if they were more than 30 days past due date for one or both vaccines according to the PCP records. RESULTS: Of 205 PCP offices contacted, we were able to obtain 173 immunization records for our analysis. Examination of vaccine records showed that 109 (63.0%) of the 173 children were up-to-date on both immunizations. When the child's caregiver was asked if shots were up-to-date, 159 (91.9%) of 173 said that all shots were given, and only 14 (8.1%) of 173 reported being behind schedule. Of the adults reporting the child up to date, 105 (66.0%) of the 159 children were confirmed to be up-to-date. Thus, 34.0% of caregivers were incorrect in stating that their child's immunization status was up-to-date for both these vaccines. CONCLUSIONS: Caregiver report was determined to be inaccurate for Hib and PCV7. Despite 91.5% of caregivers stating that shots were up-to-date, only 66.0% were correct that their child was up-to-date with these 2 vaccines. The ED physician should use caution in making clinical decisions based on the history given by a caregiver regarding their child's immunization status.

Incidence of occult upper gastrointestinal bleeding in patients presenting to the ED with hematochezia.

OBJECTIVE: The aim of the study was to determine the incidence of nasogastric (NG) aspiration revealing a clinically unsuspected upper gastrointestinal (GI) bleeding in patients presenting to the emergency department (ED) with hematochezia. A secondary aim was to identify factors associated with an upper GI source. METHODS: Data were prospectively collected from patients 18 years or older with either bright red blood per rectum or maroon stools. Patients were excluded if their history revealed hematemesis or their examination revealed melena, bleeding from an external hemorrhoid, or anal fissure. An NG tube was placed, and initial and postlavage aspirates were inspected and tested with Gastrocult (Beckman Coulter, Inc, Palo Alto, CA) for the presence of blood. Additional data included demographics, history, vital signs, and laboratory results. RESULTS: Of 114 patients, 11 (9.6%; 95% confidence interval, 4.9%-16.6%) had a positive NG aspirate. There were no statistically significant differences in age, sex, or race between the 2 groups. Factors associated with a positive aspirate were history of upper GI bleeding (P = .04), heart rate (P = .055), and hemoglobin (P = .03). CONCLUSION: Patients presenting to the ED with hematochezia require NG tube placement and aspiration to exclude an upper GI source of bleeding. History of an upper GI bleeding and anemia were associated with a positive NG aspirate.

The utility of supplemental oxygen during emergency department procedural sedation and analgesia with midazolam and fentanyl: a randomized, controlled trial.

STUDY OBJECTIVE: To determine whether supplemental oxygen reduces the incidence of hypoxia by 20% in study patients receiving midazolam and fentanyl for emergency department procedural sedation and analgesia. METHODS: Patients were randomized to receive either supplemental oxygen or compressed air by nasal cannula at 2 L per minute. Physicians were blinded to the gas used and end-tidal carbon dioxide (ETCO2) data. Respiratory depression was defined a priori as oxygen saturation less than 90%, ETCO2 level greater than 50 mm Hg, an absolute change from baseline of 10 mm Hg, or loss of the ETCO2 waveform. RESULTS: Of the 80 patients analyzed, 44 received supplemental oxygen and 36 received compressed air. Twenty supplemental oxygen patients and 19 compressed air patients met at least 1 criterion for respiratory depression. Six supplemental oxygen patients and 5 compressed air patients experienced hypoxia (P=.97; effect size 0%; 95% confidence interval -15% to +15%). Fourteen patients in each group met ETCO2 criteria for respiratory depression but were not hypoxic. Physicians identified respiratory depression in 8 of 11 patients who became hypoxic and 0 of 28 patients who met ETCO2 criteria for respiratory depression but who did not become hypoxic. There were no adverse events. CONCLUSION: Supplemental oxygen did not reduce (or trend toward reducing) the incidence of hypoxia in patients moderately sedated with midazolam and fentanyl. However, our lower-than-expected rate of hypoxia limits the power of this comparison. Blinded capnography frequently identified respiratory depression undetected by the treating physicians.