Bariatric Patients: Physiology, Airway and Ventilation, Equipment, Lifting, and Medication Dosing Practice Questions

25 multiple-choice questions on Bariatric patients: physiology, airway and ventilation, equipment, lifting, and medication dosing for paramedic and EMT students, from Chapter 46 (Patients With Special Challenges). Read each question, pick your answer, then tap Show answer to check it and read the explanation.

25 practice questions

1. A man is 1.80 m (5 ft 11 in) tall and weighs 130 kg (287 lb). His body mass index is about:

   1. A. 28
   2. B. 34
   3. C. 40
   4. D. 52
   Show answer

   Answer: C. 40

   BMI is weight in kilograms divided by height in meters squared: 130 ÷ (1.8 × 1.8) = 130 ÷ 3.24, or about 40. A BMI of 40 or more is class III (severe) obesity.

2. Class III (severe) obesity is defined as a BMI of:

   1. A. 25 to 29.9
   2. B. 40 or higher
   3. C. 30 to 34.9
   4. D. 35 to 39.9
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   Answer: B. 40 or higher

   Overweight is a BMI of 25 to 29.9, class I obesity 30 to 34.9, class II 35 to 39.9, and class III 40 or higher. A BMI of 35 to 39.9 is class II, although it may be grouped with severe obesity when serious comorbidities are present.

3. A 150-kg (331-lb) woman is in anaphylaxis. You plan to give IM epinephrine in her thigh. To make sure the drug reaches muscle, you should:

   1. A. Inject into the deltoid with a short needle
   2. B. Give the injection under the skin instead
   3. C. Give double the dose to make up for fat
   4. D. Use a longer needle for the thick tissue
   Show answer

   Answer: D. Use a longer needle for the thick tissue

   Subcutaneous fat over the anterolateral thigh is thicker than the needle on many autoinjectors in obese adults, so the drug may be deposited in fat and absorbed slowly; use a drawn-up dose with a 1.5-inch (38-mm) or longer needle per protocol, still in the thigh. A short needle in the deltoid has the same problem at a less favored site. Subcutaneous injection gives slower, less reliable absorption. The dose is weight-based to a 0.5-mg adult maximum and is not doubled for body fat. (Song 2005; anaphylaxis practice parameter 2020.)

4. A 180-kg (397-lb) woman with dyspnea says she cannot lie down. Laying her flat on the stretcher is likely to cause:

   1. A. Worsening hypoxia and respiratory distress
   2. B. Improved ventilation from chest expansion
   3. C. Hypotension from reduced fluid in the legs
   4. D. Faster oxygen delivery to the lungs
   Show answer

   Answer: A. Worsening hypoxia and respiratory distress

   Supine positioning lets the abdominal contents push on the diaphragm, reducing tidal volume and FRC; very obese patients can become severely hypoxic or even arrest when laid flat. Transport in a semi-sitting position when possible.

5. A 54-year-old man with a BMI of 52 and obesity hypoventilation syndrome is drowsy but arousable and protecting his airway, with an SpO2 of 86% and ETCO2 of 68 mmHg. The best treatment is:

   1. A. High-flow oxygen by nonrebreather alone
   2. B. Noninvasive positive-pressure ventilation
   3. C. A sedative to reduce his work of breathing
   4. D. Nebulized albuterol and observation
   Show answer

   Answer: B. Noninvasive positive-pressure ventilation

   Drowsiness with a high ETCO2 means he is not ventilating; BiPAP (or assisted bag-mask ventilation if he cannot protect his airway) lowers the CO2. Oxygen alone may raise the SpO2 while the CO2 keeps climbing.

6. A 140-kg (309-lb) man with obstructive sleep apnea who uses CPAP at night has an open ankle fracture. After fentanyl, his greatest added risk is:

   1. A. Airway obstruction and slowed breathing
   2. B. A sharp rise in blood pressure from the opioid
   3. C. An allergic reaction to the fentanyl
   4. D. Delayed pain relief from fat storage
   Show answer

   Answer: A. Airway obstruction and slowed breathing

   Patients with OSA are especially prone to opioid-induced upper airway collapse and respiratory depression. Give small, titrated doses, keep him upright, monitor ETCO2 and SpO2, let him use his CPAP if available, and have naloxone and a BVM ready; consider nonopioid options per protocol. Fentanyl lowers or does not change blood pressure. True allergy to fentanyl is rare. Fat storage prolongs a lipophilic drug's effect; it does not delay the onset of IV fentanyl. (ASA OSA practice guidelines.)

7. A 46-year-old woman who had gastric bypass surgery 2 years ago becomes sweaty, shaky, and confused about 2 hours after a large meal. You should first check her:

   1. A. 12-lead ECG for ischemia
   2. B. Abdomen for a hernia
   3. C. Capillary blood glucose
   4. D. Pupils for opioid use
   Show answer

   Answer: C. Capillary blood glucose

   Late dumping (post-bariatric hypoglycemia) occurs 1 to 3 hours after a meal, when rapid absorption triggers an exaggerated insulin surge; sweating, tremor, and confusion are classic, so check and treat the glucose first. A 12-lead is useful if she has chest pain, but it does not explain these adrenergic and neuroglycopenic signs. An internal hernia causes pain and vomiting. Opioid toxicity causes small pupils and slow breathing, not sweating and tremor. (Salehi, J Clin Endocrinol Metab 2018.)

8. Bag-mask ventilation of a morbidly obese patient is most effective with:

   1. A. One rescuer and a smaller mask to seal
   2. B. A slower rate and no airway adjuncts
   3. C. Cricoid pressure applied throughout
   4. D. Two rescuers and an oral or nasal airway
   Show answer

   Answer: D. Two rescuers and an oral or nasal airway

   A two-person, two-hand mask seal plus an OPA or NPA overcomes soft-tissue obstruction and high chest wall resistance. Routine cricoid pressure is no longer recommended and can make ventilation harder.

9. Surgical cricothyrotomy in a very obese patient is more difficult because:

   1. A. Neck tissue hides the landmarks
   2. B. The cricoid cartilage is absent
   3. C. The larynx sits higher in the neck
   4. D. The trachea is narrower than normal
   Show answer

   Answer: A. Neck tissue hides the landmarks

   Thick submental and neck tissue makes the cricothyroid membrane hard to find by palpation, so a vertical skin incision is often used. The airway anatomy itself is normal.

10. Your protocol doses a drug by weight, and a patient with severe obesity can tell you her weight. Compared with your own visual estimate, her stated weight is usually:

    1. A. Less accurate, so ignore it
    2. B. Too high by about 20%
    3. C. More accurate, so use it
    4. D. Unusable unless she is weighed
    Show answer

    Answer: C. More accurate, so use it

    Clinician visual estimates of adult weight are often far off, and errors grow at the extremes of size; a patient's own stated weight is usually within a few kilograms. Use it for dosing and to check equipment weight ratings. Ignoring it in favor of a guess adds error. Self-reported weight, if anything, runs slightly low rather than 20% high, and waiting for a scale is impractical when a close stated weight is available. (Menon 2005; Fernandes 1999.)

11. A 160-kg (353-lb) woman has no visible or palpable peripheral veins and needs vascular access for medications. A suitable option is:

    1. A. IO access in the distal femur with the shortest needle
    2. B. A subclavian central line placed in the field
    3. C. Intramuscular injection of each medication
    4. D. IO access in the proximal humerus with a longer needle
    Show answer

    Answer: D. IO access in the proximal humerus with a longer needle

    In obese adults the soft tissue over the proximal humerus averages about 3 cm, so a 45-mm (yellow) needle is advised there; the proximal tibia can also be used when its landmarks can be felt, so match the needle to the tissue depth at the site you choose. A short (15-mm) needle at the distal femur is a pediatric choice and will not reach adult bone through thick tissue. Field central lines are outside most paramedic protocols and risk pneumothorax and bleeding. IM injection gives slow, unreliable absorption and cannot be used for many emergency drugs. (Kehrl, Am J Emerg Med 2016.)

12. Which medication is generally dosed on total body weight for rapid sequence intubation?

    1. A. Rocuronium
    2. B. Succinylcholine
    3. C. Vecuronium
    4. D. Fentanyl
    Show answer

    Answer: B. Succinylcholine

    Plasma cholinesterase activity and extracellular fluid rise with obesity, so succinylcholine is dosed on actual (total) body weight. Rocuronium and vecuronium are dosed on ideal body weight to avoid prolonged paralysis, and opioids such as fentanyl on lean or ideal weight.

13. A 190-kg (419-lb) man with possible spinal injury is secured on a vacuum mattress and becomes short of breath when laid flat. The best way to help his breathing is to:

    1. A. Remove him from the mattress to sit up
    2. B. Turn him prone to take the weight off his chest
    3. C. Tilt the whole cot head-up with spine aligned
    4. D. Raise his legs to improve venous return
    Show answer

    Answer: C. Tilt the whole cot head-up with spine aligned

    Lying flat lets the abdomen push the diaphragm up and shrinks lung volume; tilting the whole stretcher head-up (reverse Trendelenburg) keeps the spine aligned while easing breathing, and you can assist ventilation if needed. Sitting him up off the mattress abandons spinal alignment. Prone positioning restricts breathing further in obesity and risks positional asphyxia. Raising the legs shifts abdominal weight onto the diaphragm. (NAEMSP/ACS-COT/ACEP spinal motion restriction statement; Dixon 2005.)

14. For an obese adult in cardiac arrest, epinephrine is given:

    1. A. At the standard adult dose
    2. B. At a dose based on actual weight
    3. C. At double the usual adult dose
    4. D. After 10 minutes of CPR have passed
    Show answer

    Answer: A. At the standard adult dose

    ACLS drug doses are not adjusted for obesity: epinephrine 1 mg IV/IO every 3 to 5 minutes. A weight-based dose would be dangerously large.

15. A 230-kg (507-lb) man is in cardiac arrest, and your mechanical CPR device will not fit around his chest. You should:

    1. A. Pause CPR until a bigger device can be brought
    2. B. Do manual CPR and rotate compressors often
    3. C. Compress at a slower rate to save energy
    4. D. Use the device with the strap left loose
    Show answer

    Answer: B. Do manual CPR and rotate compressors often

    Mechanical CPR devices have chest size limits, and very large patients may not fit; give high-quality manual CPR at standard rate and depth on a firm surface and switch compressors at least every 2 minutes, or sooner if fatigue sets in. Pauses in compressions lower the chance of survival. A slower rate reduces coronary and brain perfusion. A loosely fitted device delivers ineffective compressions and can migrate onto the abdomen. (AHA 2025; LUCAS instructions for use.)

16. Before lifting a 230-kg (507-lb) patient, the most important equipment check is:

    1. A. The width of the stretcher mattress
    2. B. The number of straps on the stretcher
    3. C. The battery level of the cardiac monitor
    4. D. The weight capacity of the stretcher
    Show answer

    Answer: D. The weight capacity of the stretcher

    Standard stretchers and stair chairs have limited rated capacities, and exceeding them risks collapse and injury to patient and crew. Manufacturer ratings, not guesswork, determine whether equipment is safe. Mattress width affects comfort and the number of straps affects securing, but neither matters if the rated capacity is exceeded, and the monitor battery does not affect lifting safety.

17. You are called to a 250-kg (551-lb) man with leg cellulitis in a second-floor apartment. The best early action is to:

    1. A. Request extra lifting help and bariatric equipment
    2. B. Wait to see whether two of you can manage
    3. C. Ask the patient to walk down the stairs on his own
    4. D. Use a standard stair chair to bring him down
    Show answer

    Answer: A. Request extra lifting help and bariatric equipment

    Call for lift assistance and a bariatric unit early, because delay leads to unsafe improvised lifts. Standard stair chairs have weight limits well below this patient's weight.

18. A 210-kg (463-lb) woman at home tells you she has a ceiling lift with a sling that her caregivers use every day. To move her to your stretcher, the best plan is to:

    1. A. Lift her by hand with four rescuers
    2. B. Use her lift with her caregivers' help
    3. C. Avoid her lift because you are unfamiliar
    4. D. Drag her across the floor on a blanket
    Show answer

    Answer: B. Use her lift with her caregivers' help

    A mechanical lift that her trained caregivers use daily is the safest option for her and the crew; confirm its weight rating and let the caregivers run it while you manage lines and the stretcher. Lifting more than 200 kg by hand is a leading cause of patient and crew injury. Unfamiliarity is not a reason to avoid the device when people who use it are there. Dragging her risks skin tears, falls, and back injury. (NIOSH safe patient handling.)

19. Lateral transfer of a bariatric patient from bed to stretcher is safest when you:

    1. A. Lift the patient straight up by the sheet
    2. B. Pull the patient across by the arms
    3. C. Use a slide sheet or transfer device
    4. D. Ask the patient to roll over unaided
    Show answer

    Answer: C. Use a slide sheet or transfer device

    Slide sheets and air-assisted transfer mats reduce friction so the crew slides rather than lifts, protecting both patient and providers. Lifting straight up by the sheet puts the whole weight on the crew's backs.

20. Early hospital notification for a 220-kg (485-lb) patient is especially important because:

    1. A. The hospital needs to approve the transport in advance
    2. B. It lets the hospital divert her elsewhere
    3. C. Bariatric patients go straight to the ICU
    4. D. Staff need time to prepare bariatric equipment
    Show answer

    Answer: D. Staff need time to prepare bariatric equipment

    The receiving facility may need a bariatric bed, lift devices, large cuffs, and extra staff ready at the door. Hospitals do not need to approve transport, and a hospital with an emergency department cannot turn her away because of her size. Obesity alone does not mean ICU admission.

21. A 190-kg (419-lb) woman is embarrassed when you need help to move her. The most appropriate approach is to:

    1. A. Avoid telling her that more help is coming
    2. B. Explain that her weight puts the crew at risk
    3. C. Speak professionally and protect her dignity
    4. D. Tell her that weight loss would make this easier
    Show answer

    Answer: C. Speak professionally and protect her dignity

    Obese patients often face weight bias and may delay calling EMS because of it; matter-of-fact professionalism and privacy encourage future care-seeking. Hiding the need for help leaves her surprised by extra people, so explain it calmly as standard practice. Lifestyle advice or comments that her weight endangers the crew add shame and help no one.

22. A 52-year-old woman with a BMI of 55 has fever and confusion. During assessment you should examine her skin folds because they often hide:

    1. A. Fractures from minor falls at home
    2. B. Fungal and bacterial skin infections
    3. C. Signs of jaundice from liver failure
    4. D. Burns from heating pads used at night
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    Answer: B. Fungal and bacterial skin infections

    Moist skin folds and the panniculus are prone to intertrigo, cellulitis, and pressure injuries that can be the source of sepsis. Lift and inspect the folds, or the infection may be missed.

23. A 58-year-old woman with obesity hypoventilation syndrome is alert, with mild dyspnea and an SpO2 of 85% on room air. Her oxygen should be titrated to an SpO2 of about:

    1. A. 88% to 92%
    2. B. 94% to 98%
    3. C. 100% on a nonrebreather
    4. D. 80% to 84%
    Show answer

    Answer: A. 88% to 92%

    In chronic hypercapnic respiratory failure, including obesity hypoventilation, guidelines target 88% to 92%, because high-concentration oxygen can raise the PaCO2 within minutes (a rise shown in studies of OHS patients); watch ETCO2 and mental status, and use noninvasive ventilation if she becomes drowsy. The 94% to 98% target is for patients not at risk of hypercapnia. A nonrebreather at 100% risks CO2 narcosis. An SpO2 of 80% to 84% leaves her hypoxic. (BTS 2017; Wijesinghe 2011.)

24. A 170-kg (375-lb) man is in ventricular fibrillation. When defibrillating him, you should:

    1. A. Use half the usual energy to avoid burns
    2. B. Place the pads over breast tissue for contact
    3. C. Delay shocks until an airway is secured
    4. D. Use standard energy with firm pad contact
    Show answer

    Answer: D. Use standard energy with firm pad contact

    Standard energy levels are used; firm pad contact and anterior-posterior placement can help overcome high transthoracic impedance. Pads should not be placed over breast tissue, which raises impedance.

25. A 150-kg (331-lb) driver in a frontal crash has tachycardia and a soft abdomen without obvious distension. Abdominal assessment is limited because:

    1. A. Fat cushions the organs from serious injury
    2. B. Fat can hide distension and tenderness
    3. C. Tachycardia is a normal finding in obesity
    4. D. Pain is rarely felt through fat tissue
    Show answer

    Answer: B. Fat can hide distension and tenderness

    A thick abdominal wall masks distension, bruising, and guarding, so a normal-looking abdomen does not exclude bleeding; keep a high index of suspicion. Any cushioning effect does not explain why the exam is limited, and his tachycardia should be treated as a sign of possible bleeding rather than a normal finding. Obesity does not reduce pain perception.