Grand Rounds Recap 10/21
/Morbidity and Mortality Conference with Dr. Curry
Acute Coronary Syndrome in Pregnancy
Epidemiology
- Incidence reported at about 6/100,000 deliveries
- Maternal mortality is between 5-9%
- 75% are STEMI
- 2/3rds are anterior wall MI (LAD or LM as the culprit vessel)
Risk Factors
Many of these are typical ACS risk factors but are less prevalent in the pregnant population
- Older age (>35 years old for pregnancy is considered older age....yikes)
- Hypertension
- Diabetes
- Obesity
- Smoking
- Dyslipidemia
Complications
- Heart failure/cardiogenic shock: 38%
- Ventricular arrhythmia: 12%
- Recurrent angina/MI: 19%
- Fetal mortality: 5%
Treatment/Interventions
- Antiplatelet Therapy
- Aspirin is considered safe and should be used. Some experts recommend low dose (81mg) instead of standard 325mg
- P2Y12-receptor blockers are generally reserved for patients requiring PCI and coronary stenting
- Heparin
- Does not cross placenta so does not provide anticoagulant effect directly on the fetus
- May cause pregnancy related bleeding (threatened abortion, placenta previa, etc.)
- Considered by experts to be indicated especially if patients are going to go for PCI
- Percutaneous Coronary Intervention
- Preferred intervention/management in STEMI
- Typically reserved in NSTEMI for those with intermediate or high risk criteria or those refractory to medical therapy
- Thrombolytics
- Very controversial
- European Society of Cardiology recommends "thrombolytic therapy should be reserved for life-threatening ACS when there is no access to PCI"
- Fetal Management
- Continuous Fetal Monitoring must be initiated. This is especially true if anticoagulants are to be used.
- Consider betamethasone for fetal lung maturity in consultation with OB/GYN
Complete Heart Block
Patient with a history of 3rd degree AV block who has an temporary externalized pacemaker who presented with a transient episode of loss of consciousness at home. EKG shows pacemaker spikes which are not capturing.
- Carefully review and document all EKG's
- Difficult/psychiatrically ill patients are often the most vulnerable
- Syncope should be on the differential for every "first time seizure"
Intentional Foreign Body Ingestion
- Most cases represent a small cohort of patients
- Vast majority of patients carry a diagnosed psychiatric illness
- Can generally divide patients into four distinct subgroups:
- Malingering
- Psychosis
- Pica
- Personality disorders - most commonly borderline personality disorder
Prophylactic Antibiotics for Cirrhotic Patients with GIB
Presented a case of a patient with ESLD due to alcoholic cirrhosis who presented with profound shock and melena/hematemesis.
- 20% of cirrhotic patients with GI bleeding are found to have a bacterial infection on admission. 23% of those are SBP.
- Prophylactic antibiotic administration decreased overall mortality (RR 0.79), decreased mortality from bacterial infections (RR 0.36) and decreased rate of rebleeding (RR 0.53)
“The use of short term prophylactic antibiotics in patients with cirrhosis and GI hemmorhage, with or without ascites, has been shown not only to decrease the rate of bacterial infections but also to increase survival”
Prophylactic Antibiotic Selection
- Fluoroquinolones
- 3rd Generation Cephalosporin (ceftriaxone preferred)
- Consider adding Vancomycin in patients who are:
- Chronically on SBP suppression with an oral fluoroquinolone
- Undergoing recent or schedules large-volume paracentesis
Small-Bore Tube Thoracostomy
Presented a case of a patient with a moderate pneumothorax after a fall who received small-bore chest tube.
- Wayne pneumothorax kit is a small-bore tube thoracostomy kit which is placed using the Seldinger technique
- Comes with a stiff trocar which can lead to parynchemal puncture or subcutaneous tracking
Traumatic Cardiac Arrest
Presented a case of a young female who was unknown gestational age who presented by HEMS after MVC in cardiac arrest with loss of pulse on landing at the helipad.
- Perimortem C-Section- more accurately termed the resuscitative hysterotomy
- Can be resuscitative for mother or fetus
- Works by relieving aortocaval compression by the gravid uterus as well as decreasing fetal anoxia
- Indicated in both traumatic and nontraumatic maternal cardiac arrest
- In case series (which certainly have a bias toward good outcomes), they report that up to 74% result in a viable neonate
- Maternal and fetal survival correlate with time from arrest to delivery
- See the new AHA guidelines for maternal cardiac arrest as well as the EAST guidelines for maternal cardiac arrest in trauma.
Consultant of the Month: Ophthalmologic Emergences with Dr. Ahmed-Naqvi
- Can't remember your extra-ocular muscle innervation? Try SO4, LR6, all other 3: Superior orbital via the 4th, lateral rectus via 6th, and all the rest via 3rd nerve
- In your approach in the ED, always consider the basics: vision, pupils, pressure
- Trick of the trades:
- When using a vision card, you can allow the patient to hold the card wherever they want (within reason)
- When checking for an APD, try once or twice and then give them a break as further intents may induce hippus and obscure your exam results
True Eye Emergencies: Retrobulbar hematoma, acute angle closure glaucoma, acid/alkali burns
Eye Urgencies: Open globe (the damage has been done), muscle entrapment (you have 4-6 hours), hyphema, traumatic iritis
Not Urgent: Lid lacerations, orbital fractures without entrapment, corneal abrasions, retinal detachments
- Acute angle closure glaucoma. Patients often complain of sudden onset, intense pain (often know exactly when started) and often visual halos. Objectively they have decreased vision and pressures should be elevated above the 30s.
Hyphema: Layering of blood (versus hypopyon=WBCs) in the anterior chamber usually due to trauma. These patients require close monitoring, particularly over the first 5 days which are critical as the chance of continued bleeding/rebleeding is high. Typically recommend bed rest and HOB elevation, no nose blowing. Give atropoine to prevent spasm and pain and steroid drops to reduce inflammation. These also need an evaluation for retinal detachment via fundoscopy or US.
Orbital Fractures
- Evaluate clinically for restricted eye movements, periorbital emphysema, enopthalmos (posterior displacement of the eyeball), and check pressures via tonometry.
- Remember special presentations common in pediatric populations: 1) the white eyed presentation (eye looks completely fine but with signs of entrapment--do your exam!) and 2) Oculocardiac reflex: if the child vomits with initial impact, high predictive value of entrapment
- Test of choice for evaluation is CT Orbits, axial and coronal, 1-1.5 mm cuts
Retrobulbar Hemorrhage
- Can be thought of as a "compartment syndrome" via bleeding into the orbit with nerve compresssion; vision loss can occur within minutes to hours
- CT may show "cone sign," a coning of the posterior portion of the eye due to propulsive tension from building back pressures behind the eye
- Example of a lateral canthotomy
Open Globe
- Suspect in potential cases of penetrating ocular trauma.
- Critical signs: Full thickness corneal laceration, peaked/irregular pupils
- In the ED give systemic antibiotics (fluoroquinolones), give tetanus prophylaxis, and call your ophthalmologist for an urgent repair
Corneal Ulcers
- Commonly seen in contact lens users though not exclusively
- Important to culture FIRST prior to antibiotics->Broad spectrum antibiotics
From the ophthalmologists mouth: NEVER SEND HOME WITH A TOPICAL ANESTHETIC
Journal Club with Drs. Kircher, McKean, and Mudd
What: Randomized, open label trial of Apneic Oxygenation (ApOx) vs usual care in the Vanderbilt MICU
Who: 150 patients randomized in a 2 step fashion to get either DL/VL and either ApOX/no ApOx after usual care prior to intubation
Results: No differences in mean time to intubate or proportion of patients with O2 sat nadir <90% or <80% observed
Conclusion: ApOx does not seem to benefit patients in this study. No significant difference intime to intubate, % of patients who desaturate, duration of mechanical ventilation, ICU LOS or in-hospital mortality
Group Thoughts:
1) These were patients who escaped the Vandy ED without intubation and were subsequently intubated in the MICU ie not representative of ED patients who get intubated. Most were intubated for sepsis/hypoxic respiratory failure with trauma, head injury, and AMS excluded based on the location of the study in a MICU. Also the ‘difficult airway’ patient was explicitly excluded due to the simultaneous randomization to VL/DL.
2) Patients were pre-oxygenated with BiPap or BVM which is not true of our usual practice.
3) This was a factorial trial design in which patients were randomized twice - first to VL/DL and second to ApOx/no ApOx. Therefore they excluded difficult airways and crash peri-arrest airways. Also the outcomes with respect to VL/DL were not reported here.
4) First pass success was 67% in both arms. This is in contrast to >90% in NEER and other ED based registries.
Key statistical teaching point:
- Factorial trial design allows investigators to simultaneously study 2 interventions in a 2x2 fashion using the same study population and infrastructure. It can be an efficient method of design. However statistical analysis and power calculations assume that these two interventions act independently of each other without synergy. Your trial must be powered adequately to detect meaningful differences in both arms. Finally, it is rare that the full results of the trial are published initially
Frat et al performed a randomized controlled trial of high flow nasal cannula (50L/min at FiO2 of 1.00) vs. BiPAP vs. standard oxygen therapy (NRB mask) for pure hypoxic respiratory failure. There was no statistically significant difference between groups in the primary outcome (intubation at 28 days). However, there was a non-statistically significant trend towards decreased intubations in the high flow group vs the other two with a p=0.18. There was also a significant decrease in mortality at 90 days in the high flow nasal cannula group versus the other two. A post-hoc analysis of a non-preplanned subgroup showed significantly decreased intubations at 28 days in the high flow nasal cannula group in the patients with an PaO2/FiO2 ratio < 200.
In summary, in a group of pure hypoxic respiratory failure patients without any component of cardiogenic pulmonary edema or chronic respiratory disease, high flow nasal cannula appears to have a mortality benefit compared with standard oxygen therapy or BiPAP and may decrease intubations in patients with low PaO2/FiO2 ratios. More data however is needed to draw definitive conclusions.
Statistical teaching point: idealized versus pragmatic randomized clinical trials. In idealized trials, the groups are highly selected with a large number of excluded patients to create an ideal study group. In pragmatic trials, all comers are placed in the trial in an effort to study interventions in a "real-world" clinical scenario with very flew exclusion criteria.
Heffner AC, Swords DS, Neale MN, Jones AE. Incidence and factors associated with cardiac arrest complicating emergency airway management. Resuscitation. 2013; 84(11):1500-4.
What: Retrospective cohort study of emergency endotracheal intubations performed in the ED with analysis of subsequent post-intubation cardiac arrest
Who: Any patient >18 years of age intubated at Carolinas Medical Center during the calendar year of 2007 that did not have cardiac arrest either before or during intubation attempt
Results: Of 410 patients included in study, 17 experienced cardiac arrest after intubation attempt. Statistically significant variables included lower pre-intubation blood pressure (mean SBP ~110) and O2 saturation (higher incidence of <92%). Multivariate regression analysis also finding higher pre-intubation shock index and higher patient weight to be associated with post-intubation cardiac arrest.
Conclusions: The study found 1 in 25 of their intubations to be associated with post-intubation cardiac arrest with a subsequent increased mortality in this population. They identify pre-intubation low systolic blood pressure, low O2 saturation, high shock index, and high patient weight as associated characteristics with this complication.
Thoughts from the group: The design and statistics of this study do leave something to be desired. The regression analysis resulting in the statistical significance of shock index and weight as important predictors of post-intubation cardiac arrest is questionable, and certainly not within a realm of true predictive significance or practice changing findings. However, the paper does provide important points of discussion regarding the necessity for pre-intubation optimization of hemodynamics, oxygenation, patient positioning and physiology to optimize the patient’s chance for survival when undergoing RSI--particularly as it pertains to individuals >100 kg.
