Podcast 871: Increased Intracranial Pressure and the Cushing Reflex

10/02/23 • 3 min

1 Listener

Emergency Medical Minute

Contributor: Travis Barlock MD

Education Pearls:

The Cushing Reflex is a physiologic response to elevated intracranial pressure (ICP)

Cushing’s Triad: widened pulse pressure (systolic hypertension), bradycardia, and irregular respirations

Increased ICP results from systolic hypertension, which causes a parasympathetic reflex to drop heart rate, leading to Cushing’s Triad.
The Cushing Reflex is a sign of herniation
Treatment includes:

Hypertonic saline is comparable to mannitol and preferable in patients with hypovolemia or hyponatremia

Give 250-500mL of 3%NaCl

20% Mannitol - given at a dose of 0.5-1 g/kg

Each additional dose of 0.1 g/kg reduces ICP by 1 mm Hg

23.4% hypertonic saline is more often given in the neuro ICU
8.4% Sodium bicarbonate lowers ICP for 6 hours without causing metabolic acidosis

Non-pharmacological interventions:

Raise the head of the bed to 30-45 degrees
Remove the c-collar to improve blood flow to the head
Hyperventilation induces hypocapnia, which will vasoconsrict the cerebral arterioles
You hyperventilate on the way to the OR. Otherwise, maintain normocapnia.

References

Alnemari AM, Krafcik BM, Mansour TR, Gaudin D. A Comparison of Pharmacologic Therapeutic Agents Used for the Reduction of Intracranial Pressure After Traumatic Brain Injury. World Neurosurg. 2017;106:509-528. doi:10.1016/j.wneu.2017.07.009
Bourdeaux C, Brown J. Sodium bicarbonate lowers intracranial pressure after traumatic brain injury. Neurocrit Care. 2010;13(1):24-28. doi:10.1007/s12028-010-9368-8
Dinallo S, Waseem M. Cushing Reflex. [Updated 2023 Mar 20]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK549801/
Godoy DA, Seifi A, Garza D, Lubillo-Montenegro S, Murillo-Cabezas F. Hyperventilation therapy for control of posttraumatic intracranial hypertension. Front Neurol. 2017;8(JUL):1-13. doi:10.3389/fneur.2017.00250

Summarized by Jorge Chalit, OMSII | Edited by Meg Joyce & Jorge Chalit, OMSII

Contributor: Travis Barlock MD

Education Pearls:

The Cushing Reflex is a physiologic response to elevated intracranial pressure (ICP)

Cushing’s Triad: widened pulse pressure (systolic hypertension), bradycardia, and irregular respirations

Increased ICP results from systolic hypertension, which causes a parasympathetic reflex to drop heart rate, leading to Cushing’s Triad.
The Cushing Reflex is a sign of herniation
Treatment includes:

Hypertonic saline is comparable to mannitol and preferable in patients with hypovolemia or hyponatremia

Give 250-500mL of 3%NaCl

20% Mannitol - given at a dose of 0.5-1 g/kg

Each additional dose of 0.1 g/kg reduces ICP by 1 mm Hg

23.4% hypertonic saline is more often given in the neuro ICU
8.4% Sodium bicarbonate lowers ICP for 6 hours without causing metabolic acidosis

Non-pharmacological interventions:

Raise the head of the bed to 30-45 degrees
Remove the c-collar to improve blood flow to the head
Hyperventilation induces hypocapnia, which will vasoconsrict the cerebral arterioles
You hyperventilate on the way to the OR. Otherwise, maintain normocapnia.

References

Alnemari AM, Krafcik BM, Mansour TR, Gaudin D. A Comparison of Pharmacologic Therapeutic Agents Used for the Reduction of Intracranial Pressure After Traumatic Brain Injury. World Neurosurg. 2017;106:509-528. doi:10.1016/j.wneu.2017.07.009
Bourdeaux C, Brown J. Sodium bicarbonate lowers intracranial pressure after traumatic brain injury. Neurocrit Care. 2010;13(1):24-28. doi:10.1007/s12028-010-9368-8
Dinallo S, Waseem M. Cushing Reflex. [Updated 2023 Mar 20]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK549801/
Godoy DA, Seifi A, Garza D, Lubillo-Montenegro S, Murillo-Cabezas F. Hyperventilation therapy for control of posttraumatic intracranial hypertension. Front Neurol. 2017;8(JUL):1-13. doi:10.3389/fneur.2017.00250

Summarized by Jorge Chalit, OMSII | Edited by Meg Joyce & Jorge Chalit, OMSII

Previous Episode

On The Streets #15: Hydrofluoric Acid Case Review

Contributors:

Kalen Abbott, MD - EM Physician and Medical Director for AirLife Denver
Brendan Reiss - Flight Nurse AirLife Denver
Matt Spoon - Flight Paramedic AirLife Denver
Jordan Ourada - EMS Coordinator at Swedish Medical Center and Paramedic

Summary:

In this episode, hosted by Jordan Ourada, Brendan Reiss and Matt Spoon present a first-hand experience case of hydrofluoric acid exposure in a pediatric patient. Commentary and educational pearls are provided by EM Physician, Kalen Abbott.

The case:

The patient was a male infant who had spilled a large amount of heavy-duty acid aluminum wheel cleaner on himself while playing in his parent's garage. Unclear if he had ingested any fluid. The cleaning fluid contained a large percentage of hydrofluoric acid.
He was brought by EMS to his local hospital, who quickly decided to transport the infant by helicopter to a large Denver hospital.
Initial labs were unremarkable and the EKG was normal. Heart rate was in the 140s. Blood pressure was 110/73. Respirations were around 30 and non-labored. Chest and abdominal x-rays were unremarkable.
The patient had received a water-based decontamination and 1 gram of calcium gluconate IV.

Complications:

Immediately before leaving a nurse informed Brendan and Matt that the serum calcium was 6.8 mg/dl (normal range: 8.5 to 10.2).
During the flight, the patient went into cardiac arrest.
The patient achieved ROSC after CPR was administered in the helicopter.
Once on the ground, an I/O line was started and calcium chloride, sodium bicarb, and normal saline were administered.
Within the first 2 hours that patient received the equivalent of 310 mg/kg of calcium (the pediatric dose is 20 mg/kg)

Care resolution:

The patient ended up having a several-week stay in the pediatric ICU. There were some complications such as pulmonary hemorrhage. Calcium gluconate was continued via nebulization for several days. Ultimately, the child was weaned off the ventilator and spontaneous respirations resumed. They were able to wean the child off vasopressors and sedation over the course of several days. A gastric lavage with calcium gluconate was completed as well during the inpatient stay. The child was able to leave the hospital, neurologically intact after about 14 days.

Pearls:

Lower concentrations of acids can be more dangerous because they don’t immediately burn but rather can be absorbed systemically through the skin.
Calcium is the antidote to hydrofluoric acid exposure.
Calcium chloride has 3 times the elemental calcium as calcium gluconate.
The maximum infusion rate of calcium chloride through a peripheral line is 1 gram every 10 minutes, calcium gluconate can be infused at 1 gram every 5 minutes.
When intubating a patient with acid exposure, avoid succinylcholine because of the risk of hyperkalemia.

References

Caravati EM. Acute hydrofluoric acid exposure. Am J Emerg Med. 1988 Mar;6(2):143-50. doi: 10.1016/0735-6757(88)90053-8. PMID: 3281684.
Pepe J, Colangelo L, Biamonte F, Sonato C, Danese VC, Cecchetti V, Occhiuto M, Piazzolla V, De Martino V, Ferrone F, Minisola S, Cipriani C. Diagnosis and management of hypocalcemia. Endocrine. 2020 Sep;69(3):485-495. doi: 10.1007/s12020-020-02324-2. Epub 2020 May 4. PMID: 32367335.
Strayer RJ. Succinylcholine, rocuronium, and hyperkalemia. Am J Emerg Med. 2016 Aug;34(8):1705-6. doi: 10.1016/j.ajem.2016.05.039. Epub 2016 May 19. PMID: 27241569.
Vallentin MF, Granfeldt A, Meilandt C, Povlsen AL, Sindberg B, Holmberg MJ, Iversen BN, Mærkedahl R, Mortensen LR, Nyboe R, Vandborg MP, Tarpgaard M, Runge C, Christiansen CF, Dissing TH, Terkelsen CJ, Christensen S, Kirkegaard H, Andersen LW. Effect of Intravenous or Intraosseous Calcium vs Saline on Return of Spontaneous Circulation in Adults With Out-of-Hospital Cardiac Arrest: A Randomized Clinical Trial. JAMA. 2021 Dec 14;326(22):2268-2276. doi: 10.1001/jama.2021.20929. PMID: 34847226; PMCID: PMC8634154.

Summarized by Jeffrey Olson MS2 | Edited by Jeffrey Olson, Meg Joyce, & Jorge Chalit, OMSII

Next Episode

Mental Health Monthly #17: Mania

Contributors:

Andrew White MD - Outpatient Psychiatrist; Fellowship Trained in Addiction Psychiatry; Denver Health

Travis Barlock MD - Emergency Medicine Physician; Swedish Medical Center

Summary

In this episode of Mental Health Monthly, Dr. Travis Barlock hosts Dr. Andrew White to discuss the elements of mania that may be encountered in the emergency department. The discussion includes a helpful mnemonic to assess mania, work-up and treatment in the ED, underlying causes of mania, mental health holds, inpatient treatment, and the role of sleep in mania.

Educational Pearls

Initial assessment of suspected mania can be done via DIGFAST:

Distractibility - Individual that is unable to carry a linear, goal-directed conversation
Impulsivity - Executive functioning is impaired and patients are unable to control their behaviors
Grandiosity - Elevated mood and sense of self to delusions of grandeur
Flight of ideas - Usually described as racing thoughts
Agitation - Increase in psychomotor activity; start several projects of which they have little previous knowledge
Sleep decrease - Typically, manic episodes start with insomnia and can devolve into multiday sleeplessness
Talkativeness - More talkative than usual with pressured speech and a tangential thought process

Interviewing patients requires an understanding of mood-based mania vs. psychosis-based mania

An individual with mood-based mania will more likely be restless, whereas a patient with psychosis-based mania will be more relaxed from a psychomotor standpoint

Treatment of manic patients in the ED includes the use of antipsychotics to manage acute symptomatology

Management can be informed and directed by the patient’s history i.e. known medications that have worked for the patient

ED management of manic patients involves a work-up for a broad differential including agitated delirium, substance-induced mania, metabolic disorders, and autoimmune diseases.
Some individuals experience manic episodes from marijuana and other illicit substances
Antidepressants used in bipolar patients for suspected depression may induce mania

Important to avoid using antidepressants as first-line therapy

Mental health holds can be beneficial in patients with grave disabilities from mania

Oftentimes, undertreatment of manic episodes leads to re-hospitalization

Inpatient treatment:

Environment is important - ensure that patients get solo rooms if possible to minimize stimulation
Antipsychotics, including risperidone and olanzapine, with or without a benzodiazepine, are useful for short-term agitation
Long-term treatment involves coupled pharmacological treatments with non-pharmacological treatments

Sleep

Fractured sleep is one of the earliest warning signs that someone has an imminent manic episode
Poor sleep can be an inciting factor for mania, which then turns into a cycle that further propagates a patient’s manic episode

Summarized and edited by Jorge Chalit, OMSII | Studio production by Jeffrey Olson, MS2