Mod3: Spinal Anesthesia Part 1 Flashcards by Olivier Mba

Which anesthesia technique involves an injection of a medication into the subarachnoid space which mixes with cerebrospinal fluid (CSF), creating anesthesia in a portion of the body?

Spinal Anesthesia

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_{SPINAL ANESTHESIA}

Spinal anesthesia is also known as:

Neuraxial anesthesia

Subarachnoid block (SAB)

Intrathecal injection

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_{SPINAL ANESTHESIA}

How can surgical anesthesia from spinal anesthesia be characterized?

Rapid, Dense, Predictable

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_{SPINAL ANESTHESIA}

Which regions of the body can be anesthetized w/ spinal anesthesia?

From the upper abdomen to feet

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_{SPINAL ANESTHESIA}

A catheter can be inserted into the subarachnoid space to extend the duration of the block. This is known as

Continuous spinal

This is usually not done

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_{SPINAL ANESTHESIA}

T/F: SAB is riskier then GA for the “average patient”

False

SAB is no more or less riskier then GA for the “average patient”

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_{SPINAL ANESTHESIA - INDICATIONS}

T/F: There are No absolute indications for a spinal

True

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_{SPINAL ANESTHESIA - INDICATIONS}

Spinal anesthesia is usually indicated for operations usually below which body structure?

The umbilicus

Nipple line dermatome level is T4

Umbilicus dermatome level is T10

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_{SPINAL ANESTHESIA - INDICATIONS}

Operations below the umbilicus for which spinal anesthesia is indicated include:

Cesarean section

Hernias

TURP (transurethral resection of prostate)

Hip replacements

Lower extremity surgery

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_{SPINAL ANESTHESIA - INDICATIONS}

Beside being indicated for operations below the umbilicus, spinal anesthesia may be advantageous for which patient populations?

COPD or other respiratory diseases

Cardiac disease (±)

Potential difficult airway (controversial)

Parturients

^{(d/t inc. risk of difficult airway; allows mom baby interactions)}

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_{SPINAL ANESTHESIA - INDICATIONS}

Why is using spinal anesthesia for potential difficult airway controversial?

?!!!

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_{SPINAL ANESTHESIA - INDICATIONS}

Why is using spinal anesthesia for Parturients advantageous?

Parturients have an inc. risk of difficult airway

spinal anesthesia allows mom baby interactions

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_{SPINAL ANESTHESIA - ADVANTAGES}

What are advantages of spinal anesthesia?

Increase Patient satisfaction

^{Rapid recovery - Absence of side effects}

Don’t have to manipulate the airway

Avoid risks of GA in high-risk surgical pts. (COPD, CAD?)

Dec. incidence of DVT, blood loss, and PE’s (in hip replacement)

Decreased stress response (SNS blockade)

Decreased PONV

Decrease exposure to meds

Monitoring mental status

^{(Easier to catch changes in mental status in procedures like TURP that are a/w hyponatremia)}

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_{SPINAL ANESTHESIA - DISADVANTAGES}

May take longer than induction, why?

Potentially difficult technique

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_{SPINAL ANESTHESIA - DISADVANTAGES}

Hypotension due to?

Sympathectomy from LA

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_{SPINAL ANESTHESIA - DISADVANTAGES}

Patient usually awake; why is that a disadvantage?

It may not be suited for the patient to be “awake”

Surgeon uncomfortable with “awake” patient

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_{SPINAL ANESTHESIA - DISADVANTAGES}

Unknown or extended surgical duration, why?

?…

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_{SPINAL ANESTHESIA - DISADVANTAGES}

Unexpected surgical delay, why?

Takes time to achieve a good “block”

Is the block successfull?

Is the block holding on, and for how long?

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_{SPINAL ANESTHESIA - DISADVANTAGES}

Urinary retention, why?

Postoperative urinary retention (POUR) is common after anesthesia and surgery.

Spinal anesthetics bupivacaine and tetracaine delay the return of bladder function beyond the resolution of sensory anesthesia, and may lead to distention of thebladder beyond its normal functioning capacity.

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_{SPINAL ANESTHESIA - DISADVANTAGES}

In which clinical situations is spinal anesthesia not recommended? why not?

Emergency / trauma situations

Will delay surgical procedure

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_{Spinal Anesthesia: Contraindications}

According to the New York Society of Regional Anesthesia, what are absolute contraindications to spinal anesthesia?

Patient refusal / uncooperative patient

Uncorrected coagulopathies or thrombocytopenia

Infection at site of injection

Hypovolemia

Increased ICP

Indeterminate neurologic disease

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_{Spinal Anesthesia: Contraindications}

According to the New York Society of Regional Anesthesia, what are relative contraindications to spinal anesthesia?

Septicemia

Shock

Lumbar spine surgery, injury or disease

Unknown duration of surgery

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_{Spinal Anesthesia: Anatomy Review}

What is the initial landmark that must be palpated before initiation of spinal anesthesia?

The spinous process

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_{Spinal Anesthesia: Anatomy Review}

How do you know you have access the Epidural space?

After the ligamentum of flavum and before the dura and arachnoide, you will feel the characteristic “poop” that will take you into the Epidural space

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_{Spinal Anesthesia: Anatomy Review} What's the midline spinal neddle path from skin to Subarachnoid space (CSF)?

Skin SQ fat Supraspinous ligament Interspinous ligament Ligamentum flavum Epidural space Dura mater Subdural space (potential space) Arachnoid mater Subarachnoid space (CSF)

_{Spinal Anesthesia: Patient preparation} T/F: Before spinal anesthesia, you must ensure that all other anesthetic options have been discussed with pt

True

_{Spinal Anesthesia: Patient preparation} Complications - inform pt. of:

Potential risks and complications

_{Spinal Anesthesia: Patient preparation} Educate pt. on procedure - Explain which aspects of the procedure?

Positioning Sensations Side Effects

_{Spinal Anesthesia: Patient preparation} Educate pt. on procedure - Explain that spinal anesthesia blocks painful sensations, but may not block which sensations?

Pressure & Movement

_{Spinal Anesthesia: Patient preparation} Educate pt. on procedure - Explain to patient that they may experience Odd sensation when legs / lower abdomen become numb

True Why is that?

_{Spinal Anesthesia: Patient preparation} Answer all pt’s questions and clear up misconceptions

True Common sense

_{Spinal Anesthesia: Patient preparation} _T/F Ensure pt. is comfortable and willing to cooperate with anesthetic technique chosen

True _{Common sense}

_{Spinal Anesthesia: Patient preparation} _T/F Ensure Informed Consent is signed

True Standard of Practice

_{Spinal Anesthesia: Patient preparation} Ensure pt has at least how many well functioning IVs?

one

_{Spinal Anesthesia: Patient preparation} Which type of fluid solution should you pre-load the pt w/? How much?

**Isotonic crystalloid** solution ## Footnote **15 ml/kg**

_{Spinal Anesthesia: Patient preparation} Pre-load w/ isotonic crystalloid solution - How much for high block?

1000 ml

_{Spinal Anesthesia: Patient preparation} Pre-load w/ isotonic crystalloid solution - How much for C-sections?

1500 ml

_{Spinal Anesthesia: Patient preparation} Pre-load w/ isotonic crystalloid solution - Be careful if CHF risk, why?

Too much fluid will exacerbate CHF

_{Spinal Anesthesia: Patient preparation} Pre-load w/ isotonic crystalloid solution - Does not prevent hypotension, why not?

?...

_{Spinal Anesthesia: Patient preparation} Place monitors; at a minimum which monitors do you need?

Pulse-ox ECG NIBP O2 _{(if indicated)}

_{Spinal Anesthesia: Patient preparation} Which Pre-medication or alternative could be used for pre-op anxiety?

Verbal encouragement Pharmacy

_{Spinal Anesthesia: Patient preparation} Why should pharmacologic agents to relieve anxiety be used with caution in spinal anesthesia?

To maintain patient cooperation

_{Spinal Anesthesia: Patient preparation} T/F: No sedation in L&D w/ spinal anesthesia

**True** Mother's cooperation needed

_{Spinal Anesthesia: Patient Positioning} What is the favorable position for spinal anesthesia? why?

**Sitting** Make then arch before they "lean forward" Back arched (“like a mad cat”) for **maximum flexion of lumbar spine**

_{Spinal Anesthesia: Sitting Positioning} T/F: Back arched (“like a mad cat”) for maximum flexion of lumbar spine, NOT LEANING FORWARD

True

_{Spinal Anesthesia: Sitting Positioning} Where would you make them sit?

Usually on **side of OR table**

_{Spinal Anesthesia: Sitting Positioning} Where are the legs and feet placed?

Legs dangling with feet on stool or chair

_{Spinal Anesthesia: Sitting Positioning} Where are the Forearms placed?

Crossed laying over pillow or on Mayo stand

_{Spinal Anesthesia: Lateral Decubitus} In the Lateral Decubitus position, how are Hips and knees placed? why?

Hips and knees **maximally flexed** This Fetal position is used to **open vertebral interspace**

_{Spinal Anesthesia: Lateral Decubitus} In this position how are the Shoulders and knees placed in reference to the bed?

Shoulders and knees perpendicular to bed

_{Spinal Anesthesia: Lateral Decubitus} Which is more challenging between sitting vs Lateral Decubitus positions?

Lateral Decubitus position is more challenging

_{Spinal Anesthesia: Lateral Decubitus} Since the Lateral Decubitus position is more challenging than the sitting position, why is it used if at all?

It is used when patient can not get into the sitting position

_{Spinal Anesthesia: Prone Jack Knife position} Why would the Prone Jack Knife position be used?

Only if position to be used for surgery

_{Spinal Anesthesia: Prone Jack Knife position} For which type of block, utilizing a LA with which baricity, and for which type of surgery would this position be used?

**Sacral block** with _hypobaric LA_ for ***perineal surgery***

_{Spinal Anesthesia: Prone Jack Knife position} T/F Will see free flow of CSF from spinal needle with this position

**False** Will not see free flow of CSF from spinal needle

_{Spinal Anesthesia: Needles} The most important characteristics of spinal needles are:

**Shape** of the tip Needle **diameter**

_{Spinal Anesthesia: Needles} Needle tip shapes that cut the dura include:

**Pitkin** or **Quincke-Babcock needle** ^{Short beveled-cutting edge (Quincke/Greene)}

_{Spinal Anesthesia: Needles} Needle tip shapes with conical or pencil-point tip include:

**Whitacre** and **Sprotte** needles

_{Spinal Anesthesia: Needles} Which spinal needle requires more force for insertion?

Pencil point (Whitacre & Sprotte)

_{Spinal Anesthesia: Needles} Why is the Pencil point (Whitacre & Sprotte) easier to ID penetration of the Dura?

Allows for *better tactile feel* of various tissues encountered Spreads dural fibers Aperture distal to tip of needle

_{Spinal Anesthesia: Needles} How do Short beveled-cutting edge (Quincke/Greene) needles enter dural fibers? Where is the needle aperture located?

Cuts dural fibers Aperture at bevel of needle

_{Spinal Anesthesia: Needles} The use of small needles reduces the incidence of

**Post–dural puncture headache (PDPH)** from 40% with a 22-G needle to less than 2% with a 29-G needle The use of larger needles, however, improves the tactile sense of needle placement, and so although 29-G needles result in a very low rate of post–dural puncture headache, the failure rate is increased

_{Spinal Anesthesia: Needles} Introducer needles (usually 18ga) are inserted into which ligament? what's their function?

Inserted into **interspinous ligament** An introducer needle can *assist with guidance* of smaller-gauge spinal needles in particular *Prevents bending* or deflection of thinner spinal needle

_{Spinal Anesthesia: Needles} What’s the advantage of using the fitted stylet?

To prevent bending and clogging of spinal needle with CSF especially the smaller guage needles

_{Spinal Anesthesia: Needles} If used, why must the fitted stylet be removed?

To assess for CSF flow or inject LA

_{Spinal Anesthesia: Needles} Which spinal needle is represented in the picture?

Whitacre

_{Spinal Anesthesia: Needles} Which spinal needle is represented in the picture?

Sprotte

_{Spinal Anesthesia: Needles} Which spinal needle is represented in the picture?

Quincke

_{Spinal Anesthesia: Needles} What is Orifice Diameter (OD) used for? What's the relationship between OD and needle gauge?

OD is used to determine gauge The smaller the OD/ the larger gauge

_{Spinal Anesthesia: Needles} What's the typical Spinal needle gauge?

22-29ga

_{Spinal Anesthesia: Needles} Needles of what gauge require introducer?

\<22ga

_{Spinal Anesthesia: Local anesthetics most commonly used} Which LA provides the most profound sensory block?

Bupivacaine

_{Spinal Anesthesia: Local anesthetics most commonly used} How long will a Bupivacaine block last?

**2-4** hours ## Footnote *Depending on dose*

_{Spinal Anesthesia: Local anesthetics most commonly used} Which LA is short acting (1 hr), and is a/w controversial use at high concentrations, d/t **transient rediculopathies**?

**Lidocaine**

_{Spinal Anesthesia: Local anesthetics most commonly used} Which LA provides the most profound motor block in spinal anesthesia?

**Tetracaine**

_{Spinal Anesthesia: Local anesthetics most commonly used} Which LA is the Longest acting in spinal anesthesia?

**Tetracaine** Longest acting (~ 4 hrs depending on dose) Aslo provides the most profound motor block

_{Spinal Anesthesia: Local anesthetics most commonly used} Which LA has the fastest onset, but also the shortest duration?

**Chloroprocaine**

_{Spinal Anesthesia: Common Spinal LA} **Lidocaine** * Dose (mg):* * Regression 2 Derm (min):* * Resolution (min):* * Prolongation (%):*

**Lidocaine** * Dose (mg):* 25 -100 * Regression 2 Derm (min):* 40-100 Resolution (min): 140-240 Prolongation (%): 20-50

_{Spinal Anesthesia: Common Spinal LA} **Marcaine (Bupivicaine) 0.75%** Dose (mg): Regression 2 Derm (min): Resolution (min): Prolongation (%):

**Marcaine (Bupivicaine) 0.75%** Dose (mg): 5-20 (15) Regression 2 Derm (min): 90-140 Resolution (min): 240-380 Prolongation (%): 20-50

_{Spinal Anesthesia: Common Spinal LA} **Tetracaine 0.5%** Dose (mg): Regression 2 Derm (min): Resolution (min): Prolongation (%):

**Tetracaine 0.5%** Dose (mg): 5-20 Regression 2 Derm (min): 90-140 Resolution (min): 240-380 Prolongation (%): 50-100

_{Spinal Anesthesia: Common Spinal LA} **Chloroprocaine** Dose (mg): Regression 2 Derm (min): Resolution (min): Prolongation (%):

**Chloroprocaine** Dose (mg): 30-100 Regression 2 Derm (min): 30-50 Resolution (min): 70-150 Prolongation (%): NR

_{Spinal Anesthesia:} What are the **Determinants** of local anesthesia spread?

Baricity and patient position Dose/volume/concentration Site of injection Patient characteristics

_{Determinants of local anesthesia spread} What are the two most important/predominant influencers of local anesthesia spread?

Baricity Patient position

_{Determinants of local anesthesia spread} We know that *Dose = Volume × Concentration*. Which of those three is the most reliable determinant of local anesthetic spread (and thus block height)?

**Dose** This is true for *isobaric* (smaller role) and *hypobaric* local anesthetic solutions This is relatively unimportant with *hyperbaric* solutions Also, **Higher concentration** = higher level block

_{Determinants of local anesthesia spread} The spread of **Hyperbaric** local anesthetic injections are primarily influenced by:

**Baricity**

_{Determinants of local anesthesia spread} **Site of injection** is a determinant of local anesthesia spread for LA with which baricity?

**Isobaric LA** _{not hyperbaric} _{This also uncertain}

_{Determinants of local anesthesia spread} How do Pregnancy and Obesity affect the spread of local anesthetic and block height?

In theory, the increased abdominal mass in obese and pregnant patients, and possible increased epidural fat, may ***decrease the CSF volume*** and therefore **increase** the **spread** of local anesthetic and **block height**. This has indeed been demonstrated using *hypobaric solutions* which are characterized by more variable spread anyway, but *not hyperbaric solutions*

_{Effect of Baricity and position on LA spread} The ratio of the density of a local anesthetic solution to the density of CSF is also known as?

**Baricity** Defined as the mass per unit volume of solution (g/mL) at a specific temperature Baricity of a local anesthetic solution is conventionally defined at 37° C The density of CSF is 1.00059 g/L (Miller) The density of CSF is 1.0003 + 0.0003 g/ml (PPT)

_{Effect of Baricity and position on LA spread} Local anesthetic solutions that have a higher density than CSF are termed

Hyperbaric Ratio of the density \>1

_{Effect of Baricity and position on LA spread} T/F The spread of hyperbaric solutions is more predictable, with less interpatient variability

True

_{Effect of Baricity and position on LA spread} Which substances are commonly added to render local anesthetic solutions either hyperbaric or hypobaric?

**Dextrose (5%-8%)** or **sterile water**, respectively

_{Effect of Baricity and position on LA spread} Why do Hyperbaric solutions will preferentially spread to the dependent regions of the spinal canal

**Gravity** It causes solutions to flow downward in CSF to most dependent region in spinal column

_{Effect of Baricity and position on LA spread} Local anesthetic solutions that have the same density as CSF are termed

**Isobaric** solutions LA solutions with density = CSF Baricity = (1.0)

_{Effect of Baricity and position on LA spread} LA without additives

Isobaric solutions

_{Effect of Baricity and position on LA spread} To obtain an isobaric solution, Lyophilized (powdered) LA\* must be reconstituted with:

**NS**

_{Effect of Baricity and position on LA spread} T/F: Isobaric solutions tend not to be influenced by gravitational forces

True Gravity has little to no effect on distribution

_{Effect of Baricity and position on LA spread} T/F: Isobaric solutions tend to create a “belt” of anesthesia

**True** What does “belt” of anesthesia mean?

_{Effect of Baricity and position on LA spread} What does “belt” of anesthesia mean?

...

_{Effect of Baricity and position on LA spread} Local anesthetic solutions that have a lower density than CSF are termed:

Hypobaric solutions LA solutions with density \< CSF Baricity = (\<0.9990)

_{Effect of Baricity and position on LA spread} To obtain an hypobaric solution, Lyophilized (powdered) LA\* must be reconstituted with:

**Sterile water**

_{Effect of Baricity and position on LA spread} Due to gravitational forces, how do Hypobaric solutions move in CSF?

**Rise** in CSF

_{Effect of Baricity and position on LA spread} What's the only commonly used lyophilized LA?

**Tetracaine** Tetracaine is an ester local anesthetic It is packaged either as niphanoid crystals (20 mg) or as an isobaric 1% solution (2 mL, 20 mg). When niphanoid crystals are used, a 1% solution is obtained by adding 2 mL of preservative-free sterile water to the crystals. Mixing 1% solution with 10% dextrose produces a 0.5% hyperbaric preparation that may be used for perineal and abdominal surgery in doses of 5 and 15 mg, respectively

_{Effect of Baricity and position on LA spread} What's a lyophilized LA?

LA supplied as a lyophilized **powder** that can be reconstituted with dextrose, NS, or sterile water prior to injection

_{Effect of Baricity and position on LA spread} Supine position and influence of normal spinal curvature

A thoughtful understanding of the natural curvatures of the vertebral column can help predict local anesthetic spread in patients placed in the horizontal supine position immediately after intrathecal administration

_{Effect of Baricity and position on LA spread} Supine position and influence of normal spinal curvature. What's the injection site of LA (Hyperbaric solutions) in the supine position

Lumbar lordosis

_{Effect of Baricity and position on LA spread} Supine position and influence of normal spinal curvature. How do Hyperbaric solutions flow when injected in the supine position?

Both **cephalad** and **caudad**

_{Effect of Baricity and position on LA spread} For Unilateral procedures in supine position using Hyperbaric solutions, how is the operative site positionned during injection?

Dependent

_{Effect of Baricity and position on LA spread} For Unilateral procedures in supine position using Hyperbaric solutions, operative site dependent during injection. What could this cause?

**Pain** | (broken hip)

_{Effect of Baricity and position on LA spread} For Unilateral procedures in supine position using Hyperbaric solutions, how long are pts left in lateral position?

Pt left in lateral position for **3-5 mins**

_{Effect of Baricity and position on LA spread} For perineal procedures using Hyperbaric solutions, how long is pt left in sitting position for “Saddle Block”?

Pt left in sitting position **5 – 10 min**

_{Effect of Baricity and position on LA spread} What's a “Saddle Block”?

Low spinal anesthesia technique that provides segmental block for those parts of the perineum, buttocks and inner thighs that would touch a saddle at the time of riding a horse

_{Effect of Baricity and position on LA spread} For Mid-high abdominal procedures using Hyperbaric solutions, how is the pt positionned?

Pt positioned **supine** with **slight trendelenburg** *Be careful – not the best option!!!??*

_{Effect of Baricity and position on LA spread} For Mid-high abdominal procedures using Hyperbaric solutions, Pt positioned supine with slight trendelenburg. Why is this not the best option?

???

_{Effect of Baricity and position on LA spread} For Perineal procedures using Hypobaric solutions, how is the pt positionned?

**Jackknife-prone** position *Again, not the best option!!!*

_{Effect of Baricity and position on LA spread} For Perineal procedures using Hypobaric solutions, pt positionned in Jackknife-prone position. Why is this not the best option?

???

_{Effect of Baricity and position on LA spread} T/F: Isobaric solutions are Not influenced by patient position or gravity

**True**

_{Factors influencing onset and duration of block} Onset of most LA:

**Within a few seconds** *Regardless of local anesthetic used*

_{Factors influencing onset and duration of block} Time to reach peak block - Lidocaine

10 min

_{Factors influencing onset and duration of block} Time to reach peak block - bupivacaine/tetracaine

20 min

_{Factors influencing onset and duration of block} What's the Principal determinant of duration of action (DOA) of a LA?

**The Drug itself** _{The DOA is drug-specific}

_{Factors influencing onset and duration of block} LA ranked from shortest duration to longest duration:

Chloroprocaine \< Lido \< Bupivacaine \< Tetracaine CLBT

_{Factors influencing onset and duration of block} How does increasing dose of LA affect level and duration of the block?

Increasing dose =\> increased level =\> increased duration

_{Factors influencing onset and duration of block} T/F: Higher the block the longer it will last

True

_{Factors influencing onset and duration of block} Higher block regresses faster than lower block, why?

Because Block is “less dense” d/t dilution in the CSF

_{Factors influencing onset and duration of block} T/F: Cephalad spread results in lower drug concentration in CSF

**True**

_{Factors influencing onset and duration of block} How does Addition of adrenergic agonists affect duration of block?

Prolongs duration of block

_{Factors influencing onset and duration of block} How does Addition of adrenergic agonists prolong duration of block?

Result of **vasoconstriction** of spinal cord vessels Leading to **decreased vascular uptake of LA**

_{Factors influencing onset and duration of block} How does Addition of adrenergic agonists causes analgesia?

**Stimulates alpha2 receptors** in spinal cord This **inhibits antinociceptive afferents** → **analgesia**

_{Factors influencing onset and duration of block} Addition of adrenergic agonists has the greatest effects with which LA?

**Tetracaine** Duration increased by 40-100% *Be aware of extended recovery time*

_{Factors influencing onset and duration of block} Compared with Tetracaine, how does addition of adrenergic agonists affect Bupivacaine?

Effects are somewhat less Duration increased by 20-50% ^{vs. 40-100% with Tetracaine}

_{Factors influencing onset and duration of block} How are effects of adding adrenergic agonists to Lidocaine?

Controversial

_{Factors influencing onset and duration of block} Which dose of Epinephrine is added to LA for spinal anesthesia?

**0.2-0.3mg** of Epi

_{Factors influencing onset and duration of block} Which dose of Phenylephrine is added to LA for spinal anesthesia

**2-5mg** of Phenylephrine

_{Factors influencing onset and duration of block} Which dose of Clonidine is added to LA for spinal anesthesia?

**75-150mg** of Clonidine

_{Factors influencing onset and duration of block} What's a benefit of adding Clonidine to LA for spinal anesthesia?

Increased analgesic properties

_{Factors influencing onset and duration of block} Adding Clonidine to LA for spinal anesthesia must be avoided in CAD and HTN, why?

....

_{Intrathecal opioids} T/F: Intrathecal opioids may be administered with or without LA

**True**

_{Intrathecal opioids} What are major benefits of **Intrathecal opioids**?

Provides **intense analgesia** M*otor* or *sympathetic* function unaffected Better *block*, better *analgesia*!!!

_{Intrathecal opioids} What are side effects of Intrathecal opioids?

Resp. depression N/V Pruritus Urinary retention

_{Intrathecal opioids} What are the most common opioids added to spinal anesthesia?

Fentanyl Duramorph Sufentanil

_{Intrathecal opioids} What are dose, onset, and DOA of **Fentanyl** when added to spinal anesthesia?

Dose: **10-25 mcg** of Fentanyl Onset: **Rapid** DOA: **2-8 hrs**

_{Intrathecal opioids} What are dose, onset, and DOA of **Duramorph (PF Morphine)** when added to spinal anesthesia?

Dose: **0.1-0.25 mg** of Duramorph (PF Morphine) Onset: **slower** DOA: **6-24 hrs**

_{Intrathecal opioids} T/F All drugs given Intrathecal must be Preservative Free (PF)

**True** Duramorph if Preservative Free (PF) Morphine

_{Intrathecal opioids} What are disadvantages of Duramorph (PF Morphine) when added to spinal anesthesia?

Delayed r**espiratory depression** May require **overnight stay**

_{Intrathecal opioids} What are dose, onset, and DOA of **Sufentanil** when added to spinal anesthesia?

Dose: **10 mcg** of **Sufentanil** Onset: **Rapid** DOA: **2-8 hrs**

_{Intrathecal opioids} What's a major side effect a/w Sufentanil when added to spinal anesthesia?

**Itching**