Neuromuscular Blockade Agents - PowerPoint Presentation

Slide1

Neuromuscular Blockade Agents(NMBAs)

A self-directed learning module for nurses

April, 2017

Slide2

Learning Objectives

By successful completion of this self-directed learning (SDL) module and achieving a passing grade of 90% on the post-test, learners will have demonstrated:

A high-level understanding of the mechanism of action of NMBAs

Knowledge of the various types of NMBAs frequently used at this facilities ICU

Indications for use of NMBAs

Knowledge of where to access additional resources related to the infusion of NMBAs

An ability to determine appropriate nursing care required for patients receiving NMBAs

Slide3

What is a NMBA?

Click on a definition

The “technical” definition:

Neuromuscular

blocking agents (NMBAs) are structurally related to

Acetylcholine

(ACh). ACh is a neurotransmitter used by the neurons to control muscles, usually via an excitatory mechanism. NMBAs interfere with the binding of Ach to the motor end plate of the neuromuscular junction.

Simplified definition:

Neuromuscular Blockade Agents, often referred to as NMBAs or “paralytics” for short, are drugs that inhibit the stimulation of muscles. If a muscle isn’t stimulated to move, it won’t move on it’s own

-

the patient is chemically paralyzed.

Slide4

Basic anatomy/physiology of neuromuscular transmission

In

order to stimulate muscle contraction, messages, in the form of electrical impulses, are sent from the brain to the spinal cord, along the nerves to the muscle

.

There are 3 major components involved in neuromuscular transmission:

The neuron

The neurotransmitter (acetylcholine)The muscle fiberThese 3 components make up the neuromuscular junction.

Slide5

Basic anatomy/physiology of neuromuscular transmission

At the

neuromuscular junction, Neurotransmitters

called

Acetylcholine (Ach)

, are released from the neuron and bind with receptors on the muscle fibre, allowing the muscle to contract.

Slide6

Here’s the process in a little more detail.

5. The influx of sodium into the muscle causes

depolarization

, which excites the muscle and causes it to contract.

Electrical impulses travel from the brain to the ends of the neurons.

2. Calcium

flows into the neuron and triggers the release of acetylcholine (

ACh

).

3. The

ACh

diffuses towards their receptor sites on the muscle fibre.

4. Once the ACh binds to its receptor site, channels open that allow sodium to enter the muscle.

6. The

ACh

is then broken down and recycled, so that is doesn’t become too concentrated and make the muscle contract for longer than it’s supposed to.

Slide7

How do NMBAs work?

There are 2 types of NMBAs based on mechanism of

action

Depolarizing

NMBAs

:

Bind to cholinergic receptors on the muscle, causing initial depolarization (just like ACh normally does), followed by continued blockade of neuromuscular transmission.

Muscle membranes are now desensitized to the effect of ACH. The depolarizing NMBA we use in our ICU is Succinylcholine.

 

Non-depolarizing NMBAs

: Competitively inhibit

ACh receptor on the muscle (ie. takes up the space on the receptor so that the ACh cannot bind there). These drugs bind to the receptor on the muscle, but no activation occurs.

The non-depolarizing NMBAs we use in our ICU are Rocuronium and Cisatracurium.

Slide8

Test your understanding

Which 3 things make up the neuromuscular junction?

Neuron, neurotransmitter, muscle fiber

Spinal cord, nerve, neuron

Nerve, muscle, tendon

What is the name of the neurotransmitter that is released from the neuron?

NorepinephrineAcetylsalicylic acidAcetylcholineAcetaminophen

Slide9

Test your knowledge

Which 2 electrolytes are mainly involved in the process of muscle contraction?

Magnesium and calcium

Potassium and magnesium

Calcium and sodium

Sodium and chloride

Slide10

Test your understanding

Put the following in the correct order:

What processes take place between the message/impulse leaving the brain and the muscle contracting?

The impulse travels from the brain to the spinal cord down to the end of the nerves

Acetylcholine is released from the neuron

Acetylcholine binds to it’s receptor on the muscle fibre

The muscle contracts

Slide11

Some indications for use…

Neuromuscular Blocking Agents (NMBA) are used

in cases where it is necessary to over-ride the body’s normal muscle activity.

They can be used as a one time dose for

patients

requiring rapid

paralysis, such as for facilitating rapid sequence intubation. They can also be used for

ongoing paralysis of skeletal muscles for the purpose

of:

facilitating mechanical ventilation by

reducing

oxygen consumptionImproving chest wall complianceEliminating ventilator dyssynchrony decreasing

energy demand in patients with severe cardiopulmonary instability preventing & treating shivering protecting the brain from the effects of prolonged seizure activity and by decreasing

intracranial pressures Reducing intra-abdominal pressures

Slide12

Did you know?

NMBAs do not provide pain relief or sedation?

They only provide paralysis!

ALWAYS

administer analgesia and sedation

BEFORE

administering NMBAs.

Slide13

NMBAs chemically paralyze the patients, making it impossible for the patient to breathe on their own.

Patient’s which will receive paralytics

in the ICU should be intubated or the

team should be in place at the head of

the bed and be prepared to intubate

immediately after the drug is administered.

As a safety precaution, it is recommended that the ordering physician administer the first dose of paralytic, or at the very leastbe present at the bedside at the time of administration.

Slide14

NMBAs most often used in the ICU setting:

Succinylcholine

An ultra-short-acting

depolarizing skeletal muscle

relaxant with a rapid onset (45 seconds) and short duration (4-5 minutes). It is often used as a single bolus for the purposes of intubation. It is incompatible with many other drugs and has many potentially dangerous side effects.

Slide15

NMBAs most often used in the ICU setting:

Cisatracurium

(

Nimbex

)

An intermediate-acting

non-depolarizing neuromuscular blocking agent, with an onset of 1.5-2 minutes and a duration of 55-60 minutes.RocuroniumAn intermediate-actingNon-depolarizing skeletal neuromuscular blocking agent, with an onset of 1-3 minutes and a duration of 22-67 minutes.

Slide16

Before you start a NMBA infusion

It’s worth mentioning again…

NMBAs

produce temporary paralysis without any analgesic, sedative effect or hearing effect. It should be assumed that the patient is awake and alert; analgesics and sedatives

must

be given

accordingly, prior to NMBA administration.Once sedation and analgesia targets are met, according to what VAMASS level is ordered, initiate neuromuscular blocking agent.NMBAs are HIGH RISK medications. Initial doses administered via IV push should be by physician. It is recommended that infusions are verified by 2 RNs prior to initiating.

Slide17

Test your knowledge

The physician is preparing to administer a bolus dose of an NMBA and has order you to start the infusion. List the interventions,

in the correct

order, that must occur prior to NMBA administration

:

Explanation of procedure to patient

Adequate analgesia and sedation administrationIntubation and mechanical ventilation (or the medical team is in place to intubate immediately following administration of the NMBA)Patient is connected to continuous cardiac monitoring

Slide18

Test your knowledge

What 2 HPHA specific resources

must

be used to determine how to prepare, start and titrate a NMBA infusion?

The Ottawa manual

The HPHA Standard Infusion binders

LexicompThe Colleague Guardian Drug Library that pharmacy programmed into our Baxter IV pumpsThe physician has ordered an NMBA to be infused in mcg/hr. However, the HPHA specific resources indicate that it should be infused in mcg/kg/min.

Place the next steps you will take in the correct order.Inform the physician that the units of measurement in his/her order do not correspond with HPHA standard measurements and thus cannot be infused using the Colleague Guardian Drug Library.

Provide the Physician with the HPHA Standard Infusion guidelines for his/her reference

Consult with the Team Leader on shift if additional support is required in communicating with the physician

If the order is not corrected, do not delay treating the patient, but have another experienced RN or the Team Leader verify the preparation and pump programming for the infusion

Complete an RL6 as this is a patient safety incident

Slide19

How to infuse NMBAs

Know

the drug you are administering- look up information about indications, administration hazards and compatibilities in a trusted reference, such as the

blue

Ottawa manual located in your medication room or use

Lexicomp

.Prepare the drug correctly according to the HPHA Standard Preparation Instructions located in the orange binder in your medication room or by using the medication resource Quick Link on

the home page of MyAllianceInfuse these HIGH RISK drugs using the

Colleague Guardian drug library.

Assess

the patient for the presence or

absence of the desired effect, and titrate accordingly

Slide20

Titrating NMBA Infusions

Given that NMBAs are administered to prevent spontaneous muscle movement, you may need to increase the rate of infusion to achieve the desired effects. The first way to know if the current dose of NMBA is sufficient is to assess your patient for the presence or absence of the desired effect.

F

or

example, t

he physician may order the infusion to be titrated to prevent the patient from working against the ventilator. In this case, you would know the infusion rate would need to be increased if the patient was stacking breaths, biting the ETT or constantly triggering high peak pressure alarms on the ventilator.

Slide21

How to titrate NMBA Infusions

Refer to the IV Adult Infusion Charts in the HPHA Standard Infusion binders to see how to titrate each drug.

Example:

Slide22

How to titrate NMBA Infusions

So, monitoring your patient for the desired effect is the primary way to determine if the current dose of NMBA infusion is sufficient, however, the physician may also order the use of a

peripheral nerve stimulator (PNS)

to determine the depth of blockade (in other words, how paralyzed someone is).

One method for measuring depth of blockade is using

Train of Four (TOF).

To do this, 4 impulses are sent from a PNS to electrodes placed over the nerve (usually on the patients wrist or face), and the nurse watches for the number of “twitches” each impulse generates.

Slide23

TOF Electrode Placement

Facial nerve

Place negative electrode (

black

)

By ear and the positive (

red) 2cmFrom the eyebrow, along theFacial nerve inferior and lateral to eyeTOF response- eyelid twitching

Ulnar nervePlace negative electrode (

black

) on wrist

In line with the little finger, 1-2cm below

The skin crease of the wrist, and positive electrode(red) 2-3 cm proximal to the black electrodeTOF

response: thumb adductionNote: do not count finger movements as these may occur as a result of muscle stimulation, not nerve.

Slide24

Monitoring Train-of Four during

Neuromuscular Blockade

(Copied from the HPHA policy & procedure)

1. Hand Hygiene

Perform hand hygiene and assess the need for PPE. 2. Skin Preparation Clean and dry the skin for electrodes by rubbing each site briskly with alcohol pad and let dry.

Clip hair if necessary. Select

most accessible site with the smallest degree of edema and hair and with no wounds, catheters or dressings that would impede accurate electrode placement over the selected nerve.

3. Applying

the Ulnar Electrodes

Extend the arm palm up in a relaxed position. Avoid arm where arterial lines or IV's are placed.

Apply two pre-gelled electrodes over the path of the ulnar nerve: Place the distal electrode on the skin at the flexor crease on the ulnar surface of the wrist, as close to the nerve as possible. Place the second electrode approx. 1-2cm proximal to the first, parallel to the flexor carpi ulnaris tendon. Use caution in selecting the site of the electrode placement in order to avoid direct stimulation of the muscle rather than the

4. PNS Set Up Plug in the lead wires to the nerve stimulator, matching the negative (black) and positive (red) leads to the black and red connection sites.

Attach the lead wires to the electrodes. Connect the negative (black) lead to the distal electrode over the crease in the palmer aspect of the wrist. Connect the positive (red) lead to the proximal electrode. Picture of lead placement

Turn on the PNS and select 9-10 on the dial on side of ICU PNS stimulator. The current (or mA) on the digital screen of the PNS should be 40 or greater to indicate adequate contact.

5. Determining the Supramaximal Stimulation (SMS)- Must be performed prior to NMBA administration

Increase the mA in increments of 10 until four twitches are observed

.

Note the amount of mA that corresponds to four vigorous twitches.

Administer

one to two more TOF stimuli.

*

Note:

Once monitoring begins, set output current one number above the maximal current so that monitoring is performed with a supramaximal current

.

6. Testing

the Ulnar Nerve

Depress

the TOF key and through visual and tactile assessment, determine twitching of the thumb and count the number of twitches.

*Note: Do not count finger movements, only the thumb

Maintain

a consistent MA current with each

stimulation

(

ie

. you will use the same supramaximal current amount for each TOF test performed on this patient once NMBAs have been administered).

Slide25

TOF continued

The

physician orders the nurse to titrate the NMBA to a certain number of twitches out of four (i.e. 2/4 twitches

). The nurse will perform TOF monitoring every 15 minutes after the infusion has begun, with every adjustment in the infusion

, and until

the ordered number of twitches is achieved. Then, TOF monitoring occurs every hour to ensure the correct level of blockade is maintained.

Slide26

TOF continued

Using a PNS has potential draw backs:

It’s subject to user error, that is peripheral

nerve stimulation results are often inconsistent with clinical findings

It requires a baseline measurement prior to administering any NMBA

Results can also be effected by improper electrode placement, poor electrode adhesion to the skin, hypothermia, and edema to the site being used

However, in the absence of more sophisticated equipment, TOF may be order by physicians to guide NMBA titration.

Slide27

What the experts say regarding TOF use…

T

he

updated (2016) clinical practice guidelines for the sustained neuromuscular blockade in the adult critically ill patient provided by the Society of Critical Care

medicine suggest

against use of PNS with train of four (TOF)

alone for monitoring depth of neuromuscular blockade in patients on continuous infusion of NMBAs. They suggest PNS with TOF monitoring may be beneficial in addition to the patient’s clinical assessment.

Slide28

If TOF monitoring is ordered…

The PNS currently used in the ICU is usually located in a small rectangular tote in the equipment room. Inside the tote are detailed, step-by-step instructions for use.

Remember to conduct a baseline TOF assessment prior to administering any bolus doses of NMBAs or starting the NMBA infusion.

This baseline measurement can be performed after sedatives and analgesics have been administered, because these drugs do not have paralytic effects, and will not alter TOF results.

Slide29

A final word on titrating NMBAs

The

routine use of a peripheral nerve stimulator

to

titrate infusions is no longer

required, but may still be ordered. You will still need to assess the patient for effect.

When physicians write NMBA infusion orders, they should identify either: the titration end-point (such as "no spontaneous ventilation trigger", "no shivering"

Or

Include

the statement "Do not titrate

"

Slide30

Test your knowledge

An NMBA infusion is ordered for a patient diagnosed with Acute Respiratory Distress Syndrome (ARDS). Which of the following would indicate that the infusion rate needs to be increased to achieve the desired effect of ventilator compliance?

A TOF of 0/4 twitches

The patient’s actual respiratory rate (RR) is 16, while the vent is set for a RR of 12.

The patient coughs after each breath

The patient is shivering

B and C

Slide31

Test your knowledge

What types of information should be provided in the Physicians order specific to a NMBA infusion?

The name of the NMBA

The desired effect the drug is being ordered to produce

The starting rate and maximum rate of the infusion

All of the above

Slide32

Risks involved with prolonged NMBA use:

Many of the risks associated with prolonged NMBA use are those associated with the accompanied prolonged ventilation and immobility

Development of ICU-acquired weakness

Prolonged mechanical ventilation (risk for VAP)

Increased risk for DVT

Corneal abrasion

Risk of awareness during paralysisAdditional risks are a result of administering NMBAs to patients with decreased liver function and the many other drugs which can inhibit, potentiate or prolong the NMBAs effect (such as Furosemide, Corticosteroids, Antibiotics, Potassium and Magnesium, just to name a few).The current

neuromuscular blockers we use have a short half life and their clearance is less dependent on

the liver or

kidney, which

reduces

some of the risk associate with drug accumulation. However, as with all medications, it is best to use the least amount of drug required for the least amount time required to produce the desired effect.

Slide33

Nursing care of the patient receiving NMBAs

Monitoring

Patients on neuromuscular blocking agents are unable to breathe or move and are dependent on mechanical ventilation.

Ensure patient is fully ventilated on a controlled rate of breathing (not on Pressure Support) before administration of a Neuromuscular Blocker (NMB).

Ensure ECG, oxygen saturation and arterial pressure alarms are on with appropriate alarm settings.

Monitor and document vital

signs as ordered, but at a minimum q1h and prn.

Slide34

Nursing care of the patient receiving NMBAs

Temperature monitoring

NMBAs

paralyze muscle activity and decrease heat production. They may be used to control metabolic rate, prevent shivering and/or facilitate hypothermia.

When used for other purposes, hypothermia may develop as a result of decreased heat production and inability to

shiver (the

use of a cooling blanket increases the potential for rapid and precipitous temperature drop even more), for this reason monitor core temperature q1h

.

Slide35

Nursing care of the patient receiving NMBAs

Assessing comfort

Maintain continuous analgesia and sedation during administration of neuromuscular blocking agents. Continue to explain all procedures to the patient.

Lacrimation (crying),

hypertension and tachycardia may be a sign of

awareness/

wakefullness or discomfort, therefore sedation and analgesia must be titrated accordingly.Do not assess for responsiveness to pain. Motor function is paralyzed but pain is sensation preserved.

Slide36

Nursing care of the patient receiving NMBAs

Provide

Corneal Protection

Blink reflex is paralyzed and lacrimation may be blocked.

Apply

ophthalmic ointment as ordered q4h

.Keep eyelids closed at all times. If eyes must be patched to maintain a closed position, caution is required to ensure the lids remain closed at all times under any patch.

Slide37

Nursing care of the patient receiving NMBAs

Range of motion

L

ack

of muscle resistance increases risk to conduct range of motion beyond normal

range, and paralysis

decreases joint and limb protection and increases risk for joint dislocation.Care should be exercised when moving the patient.Obtain physician order for Physiotherapy consult to provide passive range of motion in order to help prevent prolonged ICU-acquired weakness and problems such as foot drop.

Slide38

Nursing care of the patient receiving NMBAs

Pulmonary Care

Paralysis

of swallowing and gag reflex increases collection of oral secretions and risk for

aspiration, while

the

paralysis of the diaphragm suppresses the cough reflex and ability to clear secretions. Provide oral care q2h and prn, and regularly assess for need to suction oral secretions. Keep

HOB elevated > 30 degrees

as

tolerated.

Turn patient q2h or use rotation therapy

(for best results use the maximum degree of turn that the patient can tolerate for a minimum of 18 hours each day).

Slide39

Nursing care of the patient receiving NMBAs

DVT Prophylaxis

Paralysis of leg muscles, vasodilating nature of drug and patient immobility decreases venous return and increase risk for thrombosis

.

Maintain DVT prophylaxis with TED/SCDs and/or prophylactic anticoagulant

therapy as ordered.

Slide40

Test your knowledge

Ventilator associated pneumonia

Deep vein thrombosis

Pain, fear, anxiety

Corneal abrasion

Prolonged ICU acquired weakness

Perform

mouthcare Q2h, keep HOB >30 degrees, turn q2h.

Ensure physician completes DVT prophylaxis orders, apply TED stockings and SCDs.

Explain

procedures to the patient, provide continuous infusions of analgesia and sedation, monitor for tachycardia and hypertension

Keep eyes closed, apply ophthalmic ointment as ordered.Ensure PT has been ordered for the patient for passive range of motion, discontinue NMBA infusion as soon as possible.

Match the potential complications on the right, with the associated nursing interventions on the left.

Slide41

Discontinuing NMBA Infusions

If the NMBA infusion is ordered to be discontinued without titrating the dose down first, keep in mind the short half life of the drug and be prepared for a sudden increase in skeletal muscle activity.

Measures such as soft wrist restraint application must be taken to prevent accidental

extubation

, as the patients respiratory muscles will still be too weak to support spontaneous respiration.

Always

stop the NMBA infusion first, before weaning analgesic and sedation infusions.

Slide42

Test your knowledge

Which of the following actions would NOT be appropriate to perform prior to discontinuing an NMBA infusion?

Applying soft wrist restraints

Discontinuing the sedation and analgesia infusions

Explaining to the patient what they will soon experience

Verifying the physician order

Slide43

In a nut shell

Administer sedation and analgesia prior to administering NMBAs and administer them via continuous infusion for the duration of a NMBA infusion

Administer this high alert drug with care, using the approved infusion related resources

Remember to continue explaining all procedures to the patient, and assume they can hear and feel everything.

Monitor the patient for desired effect and for signs of NMBNA related complications.

Slide44

References

Neuromuscular Blockade in the

ICU. Clinical Practice Guideline

Update

2016.

Society of Critical Care

medicine.CARE OF THE PATIENT ON A NEUROMUSCULAR BLOCKING AGENT, LHSC, 2012.Use of neuromuscular blocking medications in critically ill patients. Karen J Tietze, PharmD Retrieved from: http://

www.uptodate.com/contents/use-of-neuromuscular-blocking-medications-in-critically-ill-patients. Up to date. 2017

Swadener

-Culpepper, L. Continuous Lateral Rotation Therapy. Critical Care Nurse.

doi

: 10.4037/ccn2010766Crit Care Nurse April 2010vol. 30 no. 2 S5-S7 Retrieved from: http://ccn.aacnjournals.org/content/30/2/S5.full

Greenberg, S., Vender, J. The Use of Neuromuscular Blocking Agents in the ICU: Where are we now? Critical Care Medicine. May 2013. Volume 41. Number 5. pp 1332-1341.Neuromuscular Junction Images: The Neuromuscular junction: function, structure and physiology. Retrieved from: http://study.com/academy/lesson/the-neuromuscular-junction-function-structure-physiology.html