Treating Laryngospasm

LARYNGOSPASM
You’re doing a procedural sedation in pediatrics. Despite your attending’s forewarning, you push that IV ketamine a bit too quickly. Suddenly, you hear a loud “crowing” or “squeaking” sound and look up at the monitor to see a flat line on capnography. Your heart sinks as it dawns upon you that you caused the much-dreaded laryngospasm.

WHAT DO I DO?!
1. Stop all procedures
2. Perform Larson’s maneuver - this is a modified jaw thrust maneuver where pressure is applied towards the top of the ramus of the mandible

3. Use a bag valve mask with PEEP valve and 100% oxygen to provide continuous positive airway pressure
4. Ask your team to prepare for intubation
5. Deepen anesthesia with IV propofol (0.5mg/kg IV push)

Most cases of laryngospasm will resolve with these maneuvers and propofol. In the rare event it doesn’t…

6. Give an IV paralytic (rocuronium 1mg/kg IV or succinylcholine 1.5mg/kg IV) and proceed to intubate.

Sources: Justin Morgenstern, "Managing laryngospasm in the emergency department", First10EM blog, March 3, 2016. Available at: https://first10em.com/laryngospasm/.

Alejandro Romero

EM PGY-3

Trauma in Pregnancy

Resuscitation of the Pregnant Trauma patient

General principles

·      Trauma is the most common cause of non-obstetrical maternal death in the United States

·      Best fetal resuscitation is good maternal resuscitation.

·      Stabilization of the pregnant women is the first priority; then, if the fetus is viable (≥ 23 weeks), fetal heart rate auscultation and fetal monitoring can be initiated and an obstetrical consultation obtained as soon as feasible

·      In Rh-negative pregnant trauma patients, quantification of maternal–fetal hemorrhage by tests such as Kleihauer-Betke should be done to determine the need for additional doses of anti-D immunoglobulin.

·      Tetanus vaccination is safe in pregnancy and should be given when indicated.

Airway

·      Greater risk for difficult intubation than non-pregnant patient

·      Pregnancy related changes à decreased functional residual capacity, reduced respiratory system compliance, increased airway resistance, and increased oxygen requirements

·      Gastric emptying is delayed in pregnancy à greater risk for aspiration

·      Respiratory tract mucosal edema à A smaller size of endotracheal tube is recommended

·      Choice of RSI medications NOT affected by pregnancy status

Breathing

·      Place chest tube one to 2 intercostal spaces higher than usual to account for displacement of the diaphragm during pregnancy

·      Marked increases in basal oxygen consumption à lower threshold for supplemental oxygen

Circulation

·      Fluid and Colloid resuscitation like standard trauma protocol

·      Uteroplacental vasculature is highly responsive to vasopressors, and their administration may decrease placental perfusion à vasopressors should be avoided unless refractory

·      Avoid supine hypotension: Compression of IVC by the uterus can cause up to 30% reduction in cardiac output à Place in left lateral position or by manual displacement of the uterus while the injured patient is secured in the supine position

·      O-negative blood should be transfused in order to avoid Rh sensitization in Rh-negative women

·      Vital signs: heart rate increases by 15% during pregnancy. Tachycardia and hypotension, typical of hypovolemic shock, may appear late in the pregnant trauma patient because of her increased blood volume.

·      Maternal vital signs and perfusion may be preserved at the expense of uteroplacental perfusion, delaying the occurrence of signs of hypovolemic shock

·      Attempt to obtain supra-diaphragmatic intravenous or intraosseous access for volume resuscitation and medication administration.

FAST

·      The FAST is less sensitive for free fluid in the pregnant patient than in non-pregnant patients.  Sensitivity decreases with increasing gestational age, likely due to altered fluid flow within the abdomen.

·      Management of suspected placental abruption should not be delayed pending confirmation by ultrasonography as ultrasound is not a sensitive tool for its diagnosis.

Secondary survey

·      In cases of vaginal bleeding at or after 23 weeks, speculum or digital vaginal examination should be deferred until placenta previa is excluded by a prior or current ultrasound scan.

Imaging

·      Radiographic studies indicated for maternal evaluation including abdominal computed tomography should not be deferred or delayed due to concerns regarding fetal exposure to radiation.

·      Ionizing radiation has the highest teratogenic potential during the period of organogenesis (5–10 weeks), with an increased risk of miscarriage before this period.

·      With abdominal CT during the third trimester the fetal exposure is around 3.5 rads, which is still under the threshold for fetal damage

·      Contrast agents should be used if indicated.

Resuscitative Hysterotomy in Cardiac Arrest

·      Should begin within 4 minutes and completed within 5 minutes of cardiac arrest

·      Both maternal and fetal survival decrease significantly after 5 minutes

·      Do NOT delay the procedure for the arrival of an obstetrician or neonatologist.

·      Do NOT evaluate for fetal cardiac activity or tocometry.

·      Do NOT prepare a sterile field (but be as clean as possible).

·      Do NOT transport to an alternative location.

·      Performing RH increases maternal cardiac output by 30%.

References:

Tamingthesru.com

EmDocs

Jain, Venu, et al. "Guidelines for the management of a pregnant trauma patient." Journal of Obstetrics and Gynaecology Canada 37.6 (2015): 553-571.

Smith, Kurt A., and Suzanne Bryce. "Trauma in the pregnant patient: an evidence-based approach to management." Emergency medicine practice 15.4 (2013): 1-18.

Holy smokes! Inhalation Injury

First steps (stable pt)
-treat as a trauma pt (ABCDE) and look for traumatic injuries
-place pt on NRB with O2 to 15 L/m
—add nebs 4% lidocaine early to prepare for visualization of cords with videolargynoscope
–4:2:1 rule for burn pt fluid resuscitation
—give fluids even if no external burns visible, as pt will have insensible losses
-treat pain!
-evaluate cords and surrounding laryngeal structures for edema with video laryngoscope or bronch

How to risk-stratify your patient with suspected smoke inhalation injury:

Rule out
–carbon monoxide toxicity: obtain serial blood gases (send co-oximetry) to monitor carboxyHb. Normal levels are 5 – 12%, depending on whether or not the pt is a smoker. Also consider if family presents with similar vague symptoms.
-cyanide toxicity: cyanide levels are not reliable in excluding toxicity, as it is rapidly cleared, and don’t result for days. Use lactate>8 or rising lactate despite fluid resuscitation to raise suspicion for toxicity
—ddx for elevated lactate (=impaired tissue oxygenation) in burn pt: cyanide, metHb, hypoxia, volume depletion
-look for rhabdo and AKI

Warning signs of respiratory failure
–drooling or difficulty swallowing = impending failure
-monitor for stridor, hoarseness, and respiratory distress
-PaO2/FiO2 ratio indicates degree of pulmonary shunting past injured lung. PaO2/FiO2<300 forewarns respiratory failure

Intubation
-early elective intubation in a controlled setting is better than crash intubation of a pt with edematous airway structures
-Prepare multiple sizes ETTs in anticipation of vocal cord edema. Use the largest that will fit so that the pt can get a bronchoscopy upstairs. Prepare suction for soot-filled secretions. Sux is safe to use up to 24h post-burn.
-use volume controlled ARDS settings (6-8 mL/kg TV)
—airways and lung become less compliant in inhalational injury, so must prevent barotrauma and allow for permissive hypercapnea