Stop Giving Your Patients Oxygen!

Stop giving oxygen.

You heard me.

Sometimes it seems like every patient in the emergency room is wearing a nasal cannula. Sometimes they're wearing it like a headband, or a necklace, or sometimes it's just spewing gas next to the stretcher. (Pause for laughter.)

But oxygen, for those who do not *need* it, may be harmful.

ACS

  • The folks at UpToDate suggest only giving oxygen if O2 is <90% on room air.

  • AHA also says only if room air sat <90%.

  • In the UK, oxygen is only recommended if the room air saturation is < 94%.

  • This amazing post from Dr. Salim Rezaie shows there is no convincing data that oxygen helps patients who aren't hypoxic, and there is some signal of harm with increased troponin/CK in patients given O2! Are we worsening their MIs?

STROKE

  • AHA says no oxygen unless saturation < 94%.

  • Journal Feed talked about this RCT of 8,000 patients, those getting supplemental O2 had no benefit.

ACUTE & CRITICAL CARE

So what's the ideal saturation?

In our critically ill patients, it's reasonable to aim for a sat of 94-98% based on a huge retrospective study in Chest.


Drowning and Submersion Injuries

For today's POTD, we're going to talk about drowning/submersion injuries. Hopefully you don't have to take care of a jet-skiier that gets pulled out of the East river this weekend, but in case you do, here's some tips to prepare you!

Epidemiology: 20% of deaths involve children < 14 yo, a leading cause of death in children < 5yo, typically in swimming pools, bathtubs, buckets. 

History of seizures and cardiac disease increases the risk of drowning.

Bimodal distribution with second peak usually (80%) in males 15-25 yo, alcohol involved in up to 70% of cases. Typically rivers, lakes, beaches.

Pathophys: Fluid aspiration => loss of surfactant, pulmonary edema, hypoxemia from V/Q mismatch

ED Management: ACLS if in cardiac arrest, it is usually a respiratory arrest. Remove wet clothing and use rewarming techniques. Initial CXR often normal. Assess for signs of trauma. C-spine injuries are uncommon (<5%) but still evaluate for trauma especially if unwitnessed event. Intubate if O2 sat < 90% despite supplemental O2, PaO2 < 60, or PaCO2>50 as hypoxemia is the major issue. If able to protect airway, BIPAP for positive pressure.

Fresh water vs. salt water drowning distinctions do not matter much because you need to aspirate more than 11mL/kg of body weight to get blood volume changes and even more to get electrolyte changes. Most nonfatal drowning victims aspirate at most 3-4 mL/kg.

Meds: none really helpful, it is supportive care. Steroids and antibiotics have not been shown to help.

Dispo: admit if any symptoms on arrive to hospital, at least for monitoring. If asymptomatic after a near drowning, monitor for at least 4-6 hours.  

Sources

https://www.nuemblog.com/blog/drowning

https://www.saem.org/cdem/education/online-education/m4-curriculum/group-m4-environmental/drowing

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Palliative Dyspnea

Managing dyspnea in the palliative patient.

This comes down to 4 approaches:

  • Oxygen

  • Opiates

  • Benzodiazepenes

  • Addressing the underlying issue

  • Other measures of comfort

Oxygen

  • Several options here with pro's and con's to all

  • Nasal Cannula 

    • Comfortable at low flows

    • Limited in how much oxygen it can deliver as it provides no reservoir of oxygen; it depends on the patient's upper airway as the reservoir of oxygen

    • at high flow rates is uncomfortable and causes dryness and bleeding unless delivered with a humidifier)

    • Many patients mouth breathe at the end of life

  • Non-rebreather

    • provides more oxygen, enables oxygen delivery to mouth breathers

    • Uncomfortably noisy, must be drawn tightly against the face to be most effective

    • muffles communication at a time when it is of key importance in the dying patient

    • Dries patient's mouth and nares out

  • Venturi Mask

    • An underutilized therapy

    • Addresses mouth breathing

    • Mixes oxygen with room air

    • Able to provide relatively high flow rates of oxygen 

    • Does not need to be humidified as high flow rates of oxygen are mixed with ambient room air

  • High-flow nasal cannula

    • Comfortably provides humidified oxygen at extremely high rates

    • Does not provide oxygen to mouth breathers

    • If the patient is being admitted it requires admission to the MICU (or potentially PAMCU)

  • Non invasive ventilation (Bipap)

    • Noisy, uncomfortable, frightening

    • Decreases the ability to commmunicate

Opioids

  • THE KEY TO PALLIATIVE DYSPNEA

  • Can be delivered via the subcutaneous route, another underutilized therapy

  • Administer zofran to offset possible associated nausea

  • Decrease the intensity of air hunger and dyspnea related anxiety

  • Have been shown to NOT SHORTEN LIFE IN PALLIATIVE PATIENTS, which is important to communicate to the dying patient's family. 

Benzodiazepenes

  • Anxiety leads to worsening dyspnea; managing the anxiety therefore aids in management of dyspnea

  • Generally not used as monotherapy, however can be used in addition with opiates in the anxious and dyspneic patient

Other measures

  • Position the patient as they wish, though generally the more upright patient is the more comfortable patient

  • Death rattle: As patients lose consciousness they lose their ability to swallow and oral secretions can pool, causing gurgling noises. There is no evidence that this is disturbing to patients, but families often have a very hard time with these noises.

    • Glycopyrrolate can help mitigate this disturbing noise

Cause specific techniques = address the underlying issue

  • Must weigh the benefits vs. the discomfort of performing these interventions

  • Pleural effusions: Thoracentesis

  • Anemia: Transfusion

  • Obstructing airway mass: Steroids, palliative radiation if available

  • Pneumonia: Antibiotics

  • Fluid overload: Diuresis

  • Bronchospasm: Bronchodilators

See:

https://first10em.com/palliative-resuscitation-dyspnea/

https://www.rtmagazine.com/products-treatment/monitoring-treatment/therapy-devices/oxygen-administration-best-choice/

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