January 10, 2025

Welcome back to UH EMS-I’s Pharmacy Phriday. As we review protocol changes for 2025, we’ll focus on using sodium bicarbonate. First, we'll review the medication and its uses that were already within our protocols.

Sodium bicarbonate, often referred to as sodium bicarb or simply bicarb, is an alkalinizing agent that most providers are familiar with using for various reasons in various conditions. As an alkalizer, it is used in cardiac arrest protocols where metabolic acidosis is suspected to correct the body’s pH. In the case of toxicity with sodium channel blockers and tricyclic antidepressants (TCA), sodium bicarbonate is given to increase extracellular sodium, in addition to alkalization of the body’s pH. 

Sodium bicarb is indicated in cases of suspected hyperkalemia (high serum potassium levels) based on history and ECG changes, such as a widened QRS, peaked T waves, severe bradycardia, or a sine wave. Sodium bicarb is given to inversely affect serum potassium levels. Raising the serum pH through sodium bicarbonate causes potassium to shift back into the cells, thus lowering the serum potassium.  

It is also indicated in cases of ASA or salicylate toxicity. In these cases, it is given for the alkalization effect that prevents the toxin from crossing the blood-brain barrier and increases clearance of the toxin through the urinary system.  

The dosing of sodium bicarbonate in these cases is 1 mEq/kg IV/IO regardless of the patient’s age or the condition being treated. Adults have a maximum dose of 200 mEq and pediatric patients have a maximum dose of 50 mEq. Remember to flush IV lines prior to and following the administration of sodium bicarbonate as precipitate may form when mixed with other medications. 

On to the “changes” related to sodium bicarbonate in the 2025 protocols. One of the newer algorithms in the protocols is titled “Crush Injury / Crush Syndrome.” Treatment for this type of emergency is not new, and in fact, was referenced in the existing “Hyperkalemia” algorithm but is now clarified for the provider through this newer algorithm.  

Sodium bicarbonate is just one of the medications, along with oxygen and IV fluids, that may be administered in these scenarios. In cases where hyperkalemia is suspected through ECG changes, calcium and albuterol are also added to the list of treatments. Hyperkalemia can be a fatal complication from a crush injury.  

Crush injury is defined as a prolonged compressive force that impairs muscle metabolism and circulation. Known as rhabdomyolysis, muscle tissue becomes ischemic and dies releasing harmful products. The goal of treatment in these cases is to protect the heart from hyperkalemia, protect the kidneys from being injured from excessive myoglobin, and protect the rest of the body from metabolic acidosis.  

Sodium bicarbonate is indicated in crush injuries or compartment syndrome due to metabolic acidosis and hyperkalemia. It is administered prophylactically just before extrication or release for any patient entrapped longer than 2 hours. The dosing under these circumstances is still 1 mEq/kg, but with a maximum dose of 100 mEq. It may be repeated every 30 minutes as needed.  

Sodium bicarbonate is also administered at any time there is evidence of hyperkalemia. Such evidence would present as ECG changes mentioned above. This is the reasoning for continuous ECG monitoring and serial 12 leads for patients experiencing a crush injury or compartment syndrome. Remember, treatment in these cases would also include calcium and albuterol as indicated in the “Hyperkalemia” algorithm. 

An additional point worth mentioning regarding this new algorithm is the inclusion of patients experiencing compartment syndrome. Compartment syndrome, by definition, can be caused by prolonged immobilization, prolonged compression of the torso or limbs (think of a patient who has fallen and been lying in the same position for an extended period), electrical injury, burns, etc. The use of this protocol is not limited to the typical industrial accident or entrapment incident we think of when thinking of crush injury. 

One final change regarding sodium bicarbonate in the 2025 protocols relates to its use, along with calcium, in the cardiac arrest algorithms. Though not used routinely in cardiac arrest, sodium bicarbonate may be administered when considering the “H’s & T’s.” The change is related to a heightened suspicion of hyperkalemia when considering the potential reversible causes of the arrest. Hyperkalemia should not just be considered in the “known dialysis patient” as it was listed in previous protocols, but also when a “history concerning for hyperkalemia” is present. Such histories may include end-stage renal failure, excessive use of potassium supplements, missed dialysis, crush injury as we just reviewed, or any of the others listed within the “Hyperkalemia” algorithm. 

Remember, the UHEMS 2025 Protocols can be downloaded from the UHEMS.org website or downloaded using the OneDose™ app on your smart device. 

Until our next issue, stay safe! 

Sincerely, 

The UH EMS-I Team 

University Hospitals 

June 23, 2023

Dear colleagues:

Welcome to this edition of Pharmacy Phriday.  In the last edition, we reviewed the use of ASA and closed with a brief discussion of possible ASA overdoses.  Such overdoses are not an uncommon occurrence, be it accidental or intentional. 

Aspirin or salicylate toxicity is a common cause of poisoning in children and adolescents. These products are readily found in the home in over-the-counter medications and products that include ASA, wintergreen, Pepto-Bismol, Alka-Seltzer, Ben Gay, and other herbal oils and supplements, just to name a few.   Data from poison control centers indicate that 1 of 4 medication-related deaths are related to ASA alone or in combination with other medications.  Prompt diagnoses and action are necessary for favorable outcomes in these cases.  A delay in diagnosis can increase mortality by 15-25%. Treatment with Sodium Bicarb is a critical part of a successful outcome for these patients.  In the 2023 UH EMS Protocols (uhems.org/protocols), the “Toxic Ingestion/Exposure/Overdose” protocols were expanded to address such cases. 

To many of our “older or experienced” providers, Sodium Bicarb was a drug used late in cardiac arrests when considering the “H’s & T’s” of ACLS.  Over time, the use of the medication was focused on patients who were more likely to be acidotic, such as adult patients on dialysis and patients with specific EKG abnormalities like a sine wave.  Even more recent considerations for the use of Sodium Bicarb within EMS protocols now include toxic exposures or overdoses in the adult or pediatric patients with evidence of a tricyclic antidepressant or sodium channel blocker overdose. These uses remain in the protocols and are, in fact, used more frequently than one might think.

Sodium Bicarbonate is given for various reasons in various conditions.  As an alkalinizer, it is used in cases of metabolic acidosis to correct the body’s pH.  In the case of toxicity with sodium channel blockers and Tricyclate Antidepressants (TCA), Sodium Bicarb is given to increase extracellular sodium in addition to alkalization of the body’s pH.  In cases of ASA or salicylate toxicity Sodium Bicarb is administered for the alkalization effect that prevents the toxin from crossing the blood-brain barrier and increases clearance of the toxin through the urinary system. 

Dosing for Sodium Bicarbonate is 1 mEq/kg IV/IO, regardless of the patient’s age or the condition being treated. Adults have a maximum dose of 200 mEq, and pediatric patients have a maximum dose of 50 mEq. Remember to flush IV lines prior to and following administration, as Sodium Bicarb may cause a precipitate to form with some other medications.

One additional note regarding the administration of Sodium Bicarb in the setting of calcium channel blockers or TCA toxicity is worth mentioning.  In such cases, a classic sign of the toxicity is a widened QRS (>120ms or 3 small boxes) and a tall terminal R wave in the aVR lead.  IV sodium bicarbonate is indicated with such presentation of hemodynamic and ECG abnormalities due to the very high risk of an adverse outcome without aggressive treatment.  In these cases, the medication is titrated and administered as a slow IV push until the QRS narrows. 

In these emergencies, Sodium Bicarb is a crucial part of the treatment for a successful outcome, but many other considerations, medications, and concerns must be included in the treatment plan.  Online medical direction is often beneficial in such complicated cases.  To complete a more in-depth review of some of these emergencies, visit the UH Prehospital Paradigm Podcast on cardiotoxins HERE or ask your EMS coordinator to review the UH CE presentation on toxicology presented in March of 2022.

Till the next time, stay safe!

Sincerely,

The UH EMS-I Team

University Hospitals

September 19, 2022

Dear Colleagues,

One of the important ways the body can remain healthy is by keeping things in balance. Homeostasis is the process of maintaining tight parameters for essential elements like water and vital systems such as blood pressure. Acid-base balance is no different. Hydrogen ions (acids) in the body are in constant struggle with bicarbonates (alkali) in an effort to maintain a steady pH. In fact, pH stands for “potential of hydrogen.” 

The pH of the body should stay between 7.35 and 7.45, and there are three mechanisms to ensure this happens. The first is the buffer system. Bicarbonate and carbonic acid patrol the bloodstream and tweak the pH when it starts to go astray. If the buffer system cannot keep it in check, the respiratory system takes over. We can see the results of breathing on pH when a patient with a slow respiratory rate due to an opioid overdose builds up carbon dioxide (respiratory acidosis) or a person hyperventilating blows off too much (respiratory alkalosis). Capnography is a great tool to monitor this. Finally, the renal system can adjust the pH by dumping or sparing various ions. When this system falls short (kidney failure), it doesn’t take much for the patient to become very ill (metabolic acidosis/alkalosis).

Sodium bicarbonate has been in EMS protocols for quite some time. Early on, it was used in cardiac arrests to counter the effect of respiratory acidosis due to the patient not breathing. The thinking was that there would be a better chance to resuscitate a patient if their pH was within normal parameters. Unfortunately, we don’t really know what the pH is until labs are run.

Recently, sodium bicarb has been targeted to specific patients who are more likely to be acidotic. Those include adult patients on dialysis who have specific EKG abnormalities like a sine wave or those in cardiac arrest. It also is warranted in adult or pediatric patients with evidence of a tricyclic or sodium channel blocker overdose. In this example, it’s the sodium in the sodium bicarbonate that is effective.

Dosing for sodium bicarbonate is set at 1 meq/kg IV/IO regardless of patient age or which protocol. Adults have a maximum dose of 200 meq for cardiac arrest and titrated to effect for overdoses. Pediatric patients max out at 50 meq. Remember to flush lines prior to and following administration because bicarb and other medications that may be given, like calcium, do not play nicely together. 

Sincerely,

The UH EMS-I Team

University Hospitals