Short-staffed on a Tuesday night shift and not sure whether the gap calls for an RN, an LPN, or a respiratory therapist? You’re not alone. For facility administrators and DONs juggling census swings, call-outs, and tight budgets, figuring out the right level of clinical staff to fill an open shift can feel like its own full-time job especially when the wrong match means paying for a skill set you didn’t need, or worse, leaving a critical care gap uncovered.

The truth is, RNs, LPNs, and respiratory therapists aren’t interchangeable. Each brings a distinct scope of practice, and matching the right professional to the right shift directly impacts patient outcomes, survey compliance, and your bottom line. Get it right, and your facility runs smoothly even during a staffing crunch. Get it wrong, and you’re either overspending on credentials you didn’t need or under-resourcing a shift that called for more specialized care.

That’s where the right nursing staffing solutions partner makes all the difference one that understands not just nursing tiers, but respiratory staffing too. In this guide, we’ll break down exactly what RNs, LPNs, and RTs are each trained and licensed to do, how to know which one your open shift actually calls for, and how a staffing partner who covers all three (plus the logistics to support them) can save your facility time, money, and headaches.

Why This Decision Matters More Than It Seems

On paper, filling an open shift looks simple: call the agency, get a warm body with a license, move on. In practice, the level of professional you place has real consequences.

Understaffing a shift with a lower-tier clinician than the acuity calls for creates real risk: missed assessments, delayed escalation, medication errors, and if state surveyors catch it citations that follow your facility for years. Overstaffing with a higher (and more expensive) tier than necessary quietly drains your labor budget shift after shift, week after week, without anyone noticing until the quarterly numbers come in.

The fix isn’t guesswork. It’s understanding exactly what each role is trained, licensed, and legally permitted to do and building a staffing plan around actual acuity, not habit or convenience. Let’s start with the foundation: what separates an RN from an LPN from an RT.

What an RN (Registered Nurse) Actually Covers

Registered Nurses hold the broadest scope of practice among the three roles discussed here. RNs complete either an associate degree (ADN) or bachelor’s degree (BSN) in nursing, pass the NCLEX-RN licensing exam, and are trained to manage the full arc of patient care — from initial assessment through care planning, execution, and evaluation.

What RNs are typically responsible for:

• Comprehensive patient assessments and ongoing monitoring
• Developing and adjusting care plans based on changing patient status
• Administering the full range of medications, including IV push and complex drug regimens
• Starting and managing IVs, blood transfusions, and central line care (with facility-specific credentialing)
• Supervising LPNs and certified nursing assistants (CNAs)
• Communicating directly with physicians about changes in condition and treatment adjustments
• Handling complex wound care, post-surgical monitoring, and higher-acuity patients

In a per diem context, RNs are usually the right call for units with higher patient acuity think med-surg floors with unstable patients, ICU step-down, or any shift where clinical judgment and independent decision-making are likely to be tested. If your facility has patients whose condition could shift quickly and require a nurse to assess, interpret, and act without waiting for a supervisor, that’s an RN shift.

What an LPN (Licensed Practical Nurse) Actually Covers

LPNs (called LVNs Licensed Vocational Nurses in Texas and California) complete a shorter training program, typically 12–18 months, and pass the NCLEX-PN exam. Their scope of practice is real and valuable, but it’s narrower than an RN’s, and in most states, LPNs work under the supervision of an RN or physician.

What LPNs are typically responsible for:

• Routine patient care: vitals, hygiene, mobility assistance, basic wound care
• Administering most oral and some injectable medications (scope varies by state)
• Monitoring and documenting patient status, then reporting changes up to the RN
• Reinforcing patient and family education started by an RN
• Assisting with procedures and basic treatments under supervision

LPNs are often the more cost-effective and entirely appropriate choice for stable, lower-acuity patients  long-term care residents with predictable needs, rehab patients on a steady recovery track, or any unit where the primary need is consistent, hands-on care rather than complex clinical decision-making. Filling a stable LTC shift with an RN when an LPN would do the job just as well is a common (and avoidable) way facilities overspend on staffing.

What an RT (Respiratory Therapist) Actually Covers

This is where a lot of general staffing agencies fall short many simply don’t offer respiratory therapists at all, forcing facilities to source RT coverage through a separate vendor entirely. Respiratory therapists are specialists, full stop. They complete a dedicated respiratory therapy degree program, pass national board exams through the NBRC, and hold a scope of practice that neither RNs nor LPNs are trained or licensed to perform.

What RTs are typically responsible for:

• Managing ventilators, BiPAP, and CPAP equipment, including settings adjustments
• Administering breathing treatments, nebulizer therapy, and oxygen titration
• Performing arterial blood gas draws and interpreting respiratory diagnostics
• Managing tracheostomy care and airway clearance
• Responding to acute respiratory distress and assisting in emergency airway management
• Educating patients and families on home respiratory equipment and long-term management

If your facility admits patients on ventilators, NIV, or any form of advanced respiratory support, RT coverage isn’t optional it’s a regulatory and clinical necessity. A unit without dedicated RT coverage on a shift with a ventilator-dependent patient is a serious gap, one that a general nursing agency often can’t fill because respiratory therapy simply isn’t part of their staffing roster.

RN vs. LPN vs. RT: A Side-by-Side Comparison

This table is a starting point, not a substitute for a real acuity assessment but it’s usually enough to catch the most common staffing mismatch: calling in an RN for a shift an LPN could safely cover, or worse, trying to have a floor nurse manage a ventilator patient without dedicated RT support.

How to Decide Which One Your Shift Actually Needs

Rather than defaulting to “just send an RN” (the most common overcorrection administrators make when uncertain), run through these questions before you place the request:

The Real Differentiator: One Partner for Nursing and Respiratory

Here’s the piece most facilities run into eventually: your typical nurse staffing agency handles RNs and LPNs just fine but the moment you need respiratory coverage, you’re often told to call somewhere else. That means a second vendor relationship, a second credentialing process, a second point of failure when a shift needs to be filled fast.

MSI Health Solutions was built differently. By offering RN, LPN, and respiratory therapist staffing under one roof, facilities get a single point of contact who understands acuity across the full clinical spectrum not just nursing tiers, but respiratory needs too. That’s a genuine structural advantage over agencies that treat respiratory therapy as an afterthought, or don’t offer it at all.

And staffing doesn’t happen in a vacuum. Facilities managing per diem clinical coverage are often juggling the same logistical headaches on the operations side getting specimens to the lab on time, moving supplies between sites, keeping documentation moving. If your facility is also navigating those gaps, medical courier services can round out the operational side of the equation, so staffing and logistics aren’t two separate fires to put out.

Building a Smarter Per Diem Staffing Plan

The facilities that handle per diem staffing well aren’t the ones that never have gaps gaps are inevitable. They’re the ones with a plan that matches the right professional to the right shift, every time, without defaulting to guesswork or overspending out of caution.

That starts with knowing the real scope of practice behind each credential (not just the title), building acuity-based criteria into your shift requests, and working with a staffing partner who can flex across nursing and respiratory needs without forcing you into a second vendor relationship when a ventilator patient shows up on the schedule.

If your facility is navigating a staffing gap right now whether it’s a stable LTC unit needing LPN coverage, a complex med-surg shift that calls for an RN, or a patient on respiratory support who needs a qualified RT the fastest way to get it right is to talk it through with a team that staffs across all three.