Patient Positioning Flashcards
Supine Position:
- Indications
- Risks
- Cardiovascular Changes
- Respiratory Changes
- Cranial Changes
- Provides easy access to airway, IVs, less physiological changes
- Pillow under head; avoid felxion or extension of neck due to brachial plexus stretch (35 degrees in sniffing position); arms abducted <90 degrees, SUPINATED; slight leg flexion (watch DVTs if pillow under knees)
- Minimal overall; Will have initial increased VR, then increases parasympathetic compensation ( 🔽 HR, PVR) Eventual reduced VR due to pooling; careful for IVC compression in pregnant, ascites, obese
- FRC decreases 800ml due to diaphragm displacement; decreases lung volumes, diaphragmatic excursion; use PIP to help overcome loss of chest wall tone from NMB
- Minimal; auto regulation tight
Trendelenburg Position:
- Indications
- Risks
- Cardiovascular Changes
- Respiratory Changes
- Cranial Changes
- Can prevent air embolism; short term hypotension tx;
upward displacement of abd cavity contents; CVC
placement - Brachial plexus injury; shoulder brace lateral over
acromioclavicular joint; reduced LE perfusion;
face/airway
edema; ASPIRATION RISK - Increases VR up to 1L; baroreceptors activates, may
make shock worse in long term; only use short term for
shock; increases heart workload - Decreases compliance, PIP, FRC; VQ mismatch at apex
(perfusion>ventilation); risk of ASPIRATION; pulmonary
vasculature congestion; ETT may shift to RMB - Increases ICP; intraocular pressure
Reverse Trendelenburg:
- Indications
- Risks
- Cardiovascular Changes
- Respiratory Changes
- Cranial Changes
- Enhances view of upper abd contents (laparoscopy,
cholesystectomy) - Watch for foot drop and excessive plantar flexion
(damages ANTERIOR TIBIAL NERVE) - Reduces VR; preload, CO, BP; compensatory mech
blunted by anesthetics; increased work on heart - Ventilation easier; increases FRC and diaphragmatic
excursion - Blood flow decrease, ICP down 20%
Lithotomy Position:
- Indications
- Risks
- Cardiovascular Changes
- Respiratory Changes
- Cranial Changes
- GYN, GU, rectal procedures; abduct legs 30-45 degrees, flex 80-100; lower legs parallel to torso, place in stirrups simultaneously to avoid torsion
- Avoid flexion beyond 110; common perineal nerve most commonly damaged lower extremity nerve; LE compartment syndrome; move hips/legs simultaneously
- Leg elevation increases VR; perfusion change 2 mmHg per every 2.5cm above heart; transient VR/CO increase; when take legs down, hypotension (CHECK BP)
- Depending on amount of flexion, decreases diaphragm excursion; ⬇️ compliance, TV, VC; increase aspiration risk
- Transient increase in blood flow
Prone Position:
- Indications
- Risks
- Cardiovascular Changes
- Respiratory Changes
- Cranial Changes
- Usually cranial surgery; Have Wilson frame (free-hanging
abd); prepare pt on stretcher before transfer; recheck
on line placement - Check breath sounds first; Neck alignment, pressure on
eyes, nose; corneal abrasion/pressure, blindness;
line/ET displacement; always tape eyes closed; ischemic
optic neuropathy/intaoptical pressure - Thoracic outlet syndrome; IVC and aortic compression
hypotension; ⬇️ CO and BP, especially on initial move,
pooling in LE causes hypotension - VQ mismatch; post vent>perf; ant perf>vent; ⬆️ PIP,
work of breathing, decrease compliance; have free
chest excursion and use PPV to overcome effects - Obstruct venous outflow if head turned; increases ICP;
normal ICP otherwise
Nerve Damage:
- Most common overall
- Second most common
- Most common lower extremity
- Ulnar
- Brachial Plexus
- Common Peroneal Nerve
Common Brachial Plexus Injury Mechanisms (5 items)
- Neck extension
- Arm abduction >90
- Arm falling of table
- Depressed shoulders (prone/reverse Tren)
- Compression against thorax (lateral)
Radial Nerve:
- Anatomy
- Injury Mechanisms
- Symptoms
- Innervates lateral aspect of UE
- Compression usually against humerus; Surgical retractors, ether screen, BP inflation
- Loss of extension of forearm, wrist drop (loss of hand extension), loss of sensation in lateral arm/posterior forearm
Ulnar Nerve Compression:
- Anatomy
- Injury Mechanisms
- Symptoms
- Runs in grove between olecranon and medial epicondyle of humerus
- Most commonly injured nerve; compression between olecranon and medial epicondyle; severe stretch (arm falling off table); compression against bed; misplaced BP inflation
- Loss of grip, inability to abduct or feel on palmar side of 4/5th finger; atrophy (claw hand)
Common Peroneal Nerve
- Anatomy
- Injury Mechanisms
- Symptoms
- Branch of sciatic, innervates outer calf; most common lower extremity injury
- Compression of lateral knee (lithotomy or lateral)
- Foot drop; inability to evert foot or dorsiflex toes
Popliteal Nerve Injury
- Anatomy
- Injury Mechanisms
- Branch of sciatic that innervates back of knee
2. Compression behind knee (lithotomy); especially in Knee-Crutch style stirrups
Sciatic Nerve
- Anatomy
- Injury Mechanisms
- Symptoms
- Runs from buttock through lower limb, comes off L1 and S1
- Excessive rotation of hips; pressure on sciatic notch (posterior buttocks)
- Paralysis or weakness of muscles below knee; foot
drop; lateral calf and foot numbness
Femoral Nerve Injury
- Anatomy
- Injury Mechanisms
- Symptoms
- Runs length of internal thigh; branches from L2-L4
- Compression at pelvic brim; excessive angulation/abduction (>45) of thighs and external rotation (lithotomy); flexion > 110 degrees
- Loss of flexion at hip; loss of extension of knee; decreased thigh sensation
Saphenous Nerve Injury
- Anatomy
- Injury Mechanisms
- Symptoms
- Medial aspect of the thigh and calf; branch of
femoral nerve - Compression of medial aspect of leg against support bar (lithotomy)
- Parathesia medial and antemedial part of calf
Lower Compartment Syndrome
- Occurrence
- Symptoms
- Treatment
- Typically long lithotomy/lateral cases (>2-3 hours)
- Ischemia, edema, rahbdomyolysis
- Fasciotomy
Thoracic Outlet Syndrome
- Definition
- Test
- Poor circulation in vessels between upper extremities and trunk
- Extend pt hands over head for 1 minute; check perfusion
Lateral Position:
- Indications
- Risks
- Cardiovascular Changes
- Respiratory Changes
- Cranial Changes
- Kidney, lung shoulder, hip surgery
- Neutral head support, pressure on dependent eye/ear
Axillary Roll placed just below axilla; knee padding to
prevent saphenous injury, on bed to prevent common
peroneal injury - Minimal; no change in CO unless VR obstructed; BP will
be different in arms - VQ mismatch (see other slide)
- Minimal unless extreme flexion
Lateral Position VQ Mismatch:
- Awake/Spontaneous Breathing
- Anesthetized/ Spontaneous Breathing
- Anesthetized/ Mechanical Ventilation
- Dependent lung: better perfused and ventilated (lower lung volumes)
- Dependent lung: better perfused, Nondependent lung: better ventilated (VQ Mismatch)
- Dependent lung: overperfused; Nondependent lung: overventilated (worse VQ mismatch)
Sitting Position:
- Indications
- Risks
- Cardiovascular Changes
- Respiratory Changes
- Cranial Changes
- Cranial, shoulder, humeral procedures
- Avoid excessive neck flexion (2 FB between mandible and sternum); flexion can cause venous congestion, cervical nerve stretch, tongue swelling; ET tube kink; flex knees; support arms so no downward pulling to preven brachial plexus injury; flex knees to prevent sciatic injury
- Pooling of blood in LE; HYPOTENSION; HR and SVR usually blunted by anesthetics; check BP often
- Lung volumes and capacities increased; compliance increases; work of breathing decreases
- ICP and cerebral blood flow decreased
Venous Air Embolism
- Risk
- Detection
- Anytime surgical field above level of heart
- TEE (higher sensitivity) or prerecordial Doppler
(parasternal border, 2-6 ICS)
Venous Air Embolism Treatment (5 items)
- Flood surgical field with NS, apply wax to bones, close
any open vessels - D/C N20
- Place on 100% and PEEP
- Durant Maneuver: place pt in L Lat decubitus and
T-berg - Aspirate air via CVC
5 Nerve Injury Mechanisms
- Compression
- Stretching
- Trans-section
- Ischemia
- Knotting/Kinking
Brachial Plexus:
- Anatomy
- Injury Mechanisms
- Symptoms
- C5-T1; runs through vertebral foramina fasciaa, under clavicle, over first rib, to the humerus (contains ulnar, median, and radial nerve)
- Sagging at shoulders (sitting), neck flexion/extension, lateral compression against thorax (lateral), abducting arms >90 (supine/prone)
- Second most common injury: loss of motor control, paralysis/parathesia of UE
Position Documentation (4 items)
- Baseline ROM
- Inta-op position
- Use of padding, frames
- Checks done and frequency
OR Table:
- Weight Limit
- Height Limit
- Patient Position
- 136kg (300 lbs)
- 80.7 inches (6’7”)
- Body centered under central column
Ischemic Optic Neuropathy Risk Factors (7 items)
- Prone position
- Operaitve hypotension
- Operative blood loss
- Large crystaloid use
- Anemia
- PVD (diabetes/smoking)
- HTN
Venous Air Embolism Sypmtoms (6 items)
1. Mill wheel murmur (constant, machine like murmur @ parasternal border 2-6 IC space) 2. Dysrhythmias, 3. decreased ETCO2, 4. Hypotension, 5. Desaturation, 6. Nitrogen in exhaled gas