Renal Failure - July 5, 2021

Good morning,

There are over 660,000 patients in the US with kidney failure; about 470,000 are on dialysis. As an EMS professional, you are likely to encounter dialysis patients in your run area. In addition, renal failure can develop for many different reasons, with the most common being secondary to uncontrolled diabetes and/or hypertension. Other causes include autoimmune and inflammatory diseases, congenital disorders, and glomerular disorders. 

Patients who progress to end-stage renal disease, or ESRD, will need dialysis to filter their blood. There are two types of dialysis: hemodialysis and peritoneal. Hemodialysis dialysis is about ten times more common. Peritoneal dialysis involves the exchange of abdominal fluid through a catheter to achieve filtration of blood waste products. This is often done at home. Hemodialysis, on the other hand, is most common at dialysis centers and usually on a 3-time-per-week schedule, with each session lasting around 4 hours. During these sessions, the patient’s blood is filtered through a dialysis machine allowing filtration and removal of waste products, then returned to the patient’s circulatory volume. 

During dialysis, fluid and electrolyte shifts occur, which can cause problems. Hypotension may be noticed, causing dizziness or even syncope, but usually this is transient. In addition to fluids, the shift of electrolytes can also cause symptoms like headaches, malaise, and even altered mental status. This also may be transient, but sometimes will need to be corrected in the hospital if it persists. 

Patients can receive hemodialysis via several modes of access. Some patients may have arteriovenous fistulas or grafts in the arm. This allows for easy access to both arterial blood and venous return. Others may have indwelling subclavian, or femoral, catheters. Any indwelling catheters are always at risk of infection, which may quickly progress to sepsis. In addition, the regular gathering of multiple patients regularly at dialysis increases the transmission of infections, which is especially evident in this COVID-19 pandemic. For these reasons, fevers and suspected infections in these patients are treated aggressively. 

For patients with AV fistulas or grafts, bleeding is a possible complication after hemodialysis access. Due to the high pressure of these access sites, since there is arterial flow involved, hemostatic control is often difficult to achieve. Direct pressure is the most effective technique but may take time for bleeding to be controlled. Tourniquets are often not as effective and can damage the fistula or graft site. 

Patients who miss dialysis can be at risk for severe complications, including hyperkalemia and fluid overload. Without dialysis sessions to remove excess fluid, patients can develop pulmonary edema leading to respiratory distress. This can be managed similarly to other pulmonary edema patients, with oxygen and positive pressure as needed. Extra fluid volume can also accumulate in other spaces, leading to pericardial or pleural effusions. 

Elevated potassium can lead to lethal ventricular arrhythmias, and therefore needs to be quickly recognized and treated. The main signs of hyperkalemia in the prehospital setting are ECG changes. Large, peaked T waves are usually the first changes seen. As potassium levels rise, there is a loss of p waves and a widening of the QRS duration (>120 ms). If untreated, this can progress to a sinusoidal wave pattern, followed by cardiac arrest. If recognized appropriately, there a few tools to help temporize hyperkalemia. Calcium, which acts to stabilize cardiac myocytes, should be given if there are ECG changes consistent with hyperkalemia. This can act quickly to help prevent further cardiac rhythm deterioration. Albuterol nebulizers or IV sodium bicarbonate can also be given. Both help to shift potassium back into cells and out of the blood volume. All these options should be used for suspected hyperkalemia. They can help prevent lethal arrhythmias until the patient can get definitive management, which is usually in the form of emergent hemodialysis. 

With a high likelihood to encounter dialysis patients on your runs, it’s important to be aware of potential complications and ready to provide appropriate management in the prehospital setting. 

Respectfully yours,

Frank Forde, MD

BGL - July 12, 2021

Good morning,

Insulin is a hormone secreted by the beta cells in the pancreas. The primary function of insulin is to trigger receptors on the plasma membranes of cells to balance the transfer of glucose from the blood to the cells where it can be used for energy.

In Type 1 Diabetes, our patients have a lack of insulin production. It is an autoimmune disease in which the β-cells of the pancreas do not produce sufficient insulin to regulate glucose usage for cellular energy.

In type 2 Diabetes, patients have variable degrees of insulin resistance and pancreatic β-cell dysfunction. This worsens with obesity, a major contributor to insulin resistance.

Why do we continue to check blood glucose on any of our altered, confused, or weak patients? Whenever we have a patient in front of us who is acting bizarre, altered from baseline, lethargic, or even unresponsive aside from airway, blood glucose checks are our best friend. During your critical thinking process with any of these patients, keep diabetic emergencies high on your differential. Initial considerations in these super sick patients should be DKA, Hyperosmolar Hyperglycemic Syndrome (HHS), and Hypoglycemia. Important numbers to keep in mind concerning our protocols are 70 and 250.

With any glucose > 250mg/dl, which unfortunately may be a common number for many of our patients, we need to consider Diabetic Ketoacidosis (DKA). While simple hyperglycemia is not a medical emergency, without prompt control it can be. DKA is a disease that results from absolute insulin insufficiency causing metabolic acidosis. Without sufficient insulin to use glucose as energy, our bodies start breaking down fat into fatty acids -- then converted into ketones by the liver. This leads to ketoacidosis, causing the symptoms of DKA that we commonly see. This is commonly triggered by stressors such as infection, illness, or injury.

Sx: While DKA may start with the 3 P’s: polydipsia, polyuria, and polyphagia, we furthermore see abdominal pain, nausea and vomiting, confusion, fatigue, and unresponsiveness as the acidosis worsens. These patients also may appear in respiratory distress with what we call Kussmaul breathing. This is not a respiratory issue, rather it is the body's attempt to compensate by blowing off excess carbon dioxide (acid) from the severe metabolic acidosis.

Tx: The most important prehospital treatment is rapid assessment and recognition of DKA. These patients need a rapid airway assessment and 2 large bore IV’s. It is likely that they are severely dehydrated and need immediate fluid resuscitation. Once in the hospital when we can further assess electrolyte status, they will most often be started on an insulin drip and sent to the ICU. Prompt recognition of the critical nature of these patients is of utmost importance!

We will take a deeper dive into DKA, Hyperosmolar Hyperglycemic Syndrome (HHS), and Hypoglycemia next week with explanations and examples. Be well, thanks for reading, and hope you enjoy next week also. 

Dr. Zeller

Diabetes - July 19, 2021

Good morning,

Last week, we reviewed type 1 and type 2 Diabetes and initial considerations that need to be taken in diabetic emergencies.

Hyperglycemic Hyperosmolar Syndrome 

HHS is another disease with an unbelievably high mortality (10-50%). It is difficult to distinguish from DKA in the pre-hospital environment, though we can see crazy high glucose levels in these patients. This osmolar difference pulls fluid out of cells causing severe dehydration. The biggest take-home point in these patients is that they are extremely dehydrated and need immediate rehydration and rapid transport. 

Hypoglycemia 

Hypoglycemia is defined as serum glucose less than 70mg/dL. In these patients, your first tip-off to hypoglycemia is likely mental status changes, confusion, lethargy, or even changes in consciousness given the brain's strict reliance on glucose to function. The most common causes of hypoglycemia are typically taking too much insulin, not eating well, or some combination of the two.   

Tx:  

Dextrose - giving dextrose is the gold standard for the treatment of hypoglycemia 

We use D10 which is less harsh on the tissues and gives a steady glucose level rather than the spike of D50. Though you should be familiar with D50 as well. Oral glucose or a simple snack (juice or a candy bar or a sandwich) are a quick fix if the patient is alert and tolerating oral intake. 

Glucagon - Glucagon can be an adjunct to dextrose. In those patients who do not have access or are still working on a line, consider 1mg IM of Glucagon. Glucagon can take minutes to work (sometimes upwards of 8-21 minutes). It also may not be helpful in patients with liver disease, alcoholics, or kidney disease as pts need a solid glycogen store in the liver to be helpful.  

Refusals are very common in hypoglycemic patients who improve after treatment. If oral, long-acting hypoglycemic agents are involved this can be a dangerous option. Be sure to get a good medication list on these patients as medication half-lives are important! 

Be safe and keep up the awesome work! 

Dr. Zeller

Seizure - July 26, 2021

Good morning,

An estimated 3.4 million people have active epilepsy nationwide, which constitutes about 1.2% of the US population. There are different types of seizures, which can sometimes make them difficult to recognize. Seizures can be simple, where the patient is still conscious, or complex, where the patient is unconscious. In addition, seizures may be focal, only involving one part of the body, or generalized, which involves the entire body. They can also start as simple or focal, then progress to a complex generalized seizure. Patients can even have an absence seizure, which consists of staring spells, more common in the pediatric population, and seizure disorders are commonly encountered by prehospital providers across the country.

Aside from having underlying epilepsy, seizures are caused by many things, including but not limited to: hypoglycemia, head trauma, hypoxia, electrolyte disturbances, liver/kidney failure, drugs, alcohol withdrawal, medication toxicity, stroke, brain tumors, eclampsia, hyperthermia, infection, etc. Assessment of the patient should also involve looking for these possible causes, especially in a patient without prior history of seizures. Fingerstick glucose measurements should be performed for all seizure patients to rule out hypoglycemia as the cause. In addition to seizures, syncopal episodes may appear similar to seizures and even involve shaking. Often these are short-lived, and the patient returns to baseline very quickly instead of having a post-ictal period.

When encountering an actively seizing patient, the initial steps should emphasize the ABCs. This initially includes positioning, suctioning the airway, and monitoring to ensure adequate ventilation and decrease the risk of aspiration or injury. In some cases, further airway management may be required, such as utilizing Bag-Valve Mask, nasopharyngeal airway adjuncts, or advanced airways.

Most seizures resolve spontaneously within a few minutes. If this occurs and the patient is in a post-ictal state, only supportive care is indicated. If not, further intervention will be required. Prehospital treatment is mainly limited to benzodiazepine medications or benzos. The most commonly seen benzos are Midazolam (Versed) and Lorazepam (Ativan). Intramuscular Midazolam has become the most common first-line in EMS, after a 2012 research study called the RAMPART Trial, showed IM Midazolam to be more effective in stopping seizures and quicker to administer than IV Lorazepam. In addition, another study shortly after demonstrated that Midazolam does not degrade during storage in the prehospital environment, whereas Lorazepam had significant cellular degradation after 60 days, especially in hot conditions. Consequently, prehospital first-line usage of IM Midazolam rose from around 26% in 2010 to 62% in 2014 and continues to be the more popular choice.

While most EMS agencies will preferentially carry Midazolam, it is important to be comfortable with dosages of both medications. Medication shortages and cost changes are always possible so you may find yourself with either medication as your only available benzo. In the UH protocol, the Midazolam adult dosage is 2.5 mg IV/IO or 5 mg IM or intranasal with an atomizer. The dosage of Lorazepam is 1-2 mg for any route of administration.

In some instances, the patient may continue to seize or have additional seizure episodes after medication administration. These patients may require re-dosing of medications. Consider calling for medical command help for these patients whose seizures may be resistant or difficult to control.

For pediatrics, the dosage is weight-based. Midazolam pediatric dosage is 0.1 mg/kg IV or IO (max 2 mg) or 0.2 mg/kg IM or IN (max 5 mg). For Lorazepam, the peds dosage is 0.05 to 0.1 mg/kg (max 2 mg) for all routes of administration. Pediatric patients can also have febrile seizures, which are seizures brought on by fevers. This can occur even with viral illnesses and often self-resolve or be managed by cooling and treating the fever. Once the fever is treated, the patient often will improve and not have any repeated seizures. These episodes may be very frightening for parents but do not come with an increased risk of seizures later in life. Parental reassurance is often important.

While seizures can have varied presentations and causes, remembering the basics of recognition and treatment, as well as your medication dosages, will help improve the successful resolution and stabilization of these patients.

Respectfully yours,

Frank Forde, MD