Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
NU 568
Exam 3 - Positioning in the OR
| Question | Answer |
|---|---|
| What are the 3 goals of positioning? | Maximize: surgical exposure, access to patient, recovery |
| Maximal access of the patient allows for what 3 things? | Maintenance of ventilation/airway, administration of drugs, monitoring VS |
| What are 3 ways to prevent nerve injuries? | Anticipate problems, proper planning, communicate abnormal findings |
| What are the effects of positioning injuries? | Prolonged hospitalization and recovery, psychological trauma, permanent disability, increased cost |
| Of closed claims analysis, how many nerve injuries were CRNA related vs. not CRNA related? | 68% CRNA related, 32% not CRNA related |
| Of the nerve injuries directly related to CRNA care, what percentage of cases were found to be inappropriate to standards of care? | 52% |
| What are the 4 primary methods of nerve injury? | Compression, stretch, transection, kinking |
| What are some different injuries related to compression and why do they occur? | Soft tissue, nerves, and vascular structure injuries occur due to compression over an extended period of time; caused by increased tissue resistance to venous capillary outflow and decrease in pressure gradient b/w capillaries and tissue |
| Where do stretch injuries often occur? | Superficial nerves w/a long course |
| Identify a scenario whereby transection injuries can occur? | Surgical trauma |
| When do kinking nerve injuries occur? | A nerve is pinched between 2 immovable structures (i.e. exaggerated lithotomy) |
| When do compression injuries occur? | When a nerve is forced against a bony prominence or a hard surface |
| Describe the process of tissue ischemia. | 1) decreased tissue blood flow 2)anaerobic metabolism produces and accumulates acid byproducts 3)membrane Na-K pump failure 4)increased intracellular Na leads to increased osmotic gradient and edema |
| What is a common component of all peripheral nerve injuries? | Tissue ischemia |
| In an ischemic environment, decreased production of _______ leads to the failure of the Na-K pump. | ATP |
| What are 4 causes of compartment syndrome? | Prolonged operation, hypotension, extremity elevation, body habitus |
| What is compartment syndrome? | Potentially life threatening complication causing neural and vascular damage due to swelling of the muscular compartment |
| What is the definitive treatment for compartment syndrome? | fasciotomy |
| What situations may occur if compartment syndrome is not diagnosed and treated? (5) | Permanent neuromuscular damage, tissue necrosis, myoglobinuria, ARF, amputation, death |
| What are two scenarios that lead to the development of compartment syndrome? | Increased pressure and decreased tissue perfusion in muscles with tight fascial borders |
| When does tissue swelling typically occur? | When blood flow returns following a period of ischemia |
| Compartment syndrome has also been dubbed a _______. | Reperfusion injury |
| What are 4 common causes of compartment syndrome? | Trauma, embolic phenomena, tumors, vascular insufficiency |
| What are pre-disposing perioperative factors for compartment syndrome? | Tight wound closure, expanding hematoma, prolonged surgery, external compression |
| A higher incidence of compartment syndrome has been reported in what surgical positions? | Lithotomy, lateral decubitus |
| What are the 2 surgical factors that contribute to nerve injuries? | Positioning devices, length of surgery |
| A surgical length of greater than _________ hours increases the risk for nerve injury. | 4 |
| What are anesthetic factors that contribute to nerve injuries? | GA, NMB, hypotensive techniques, neuraxial/peripheral blocks |
| Why does GA pose a risk for positioning injuries? | Patient cannot verbalize or move in response to painful stimuli |
| What two types of drugs lend towards stretch injuries d/t increased mobility of joints? | NMBs and volatile anesthetics |
| Name the surgical positions where gravity affects blood flow. | Sitting, lithotomy, T-burg |
| The majority of nerve injuries are r/t what 3 factors? | Block technique, needle trauma, hematoma |
| It (is/is not) acceptable to extend the extremities of patients with multiple contractures. | Is not |
| The presence of paresthesia means that a medication (should/should not) be injected. | should not |
| What does the presence of paresthesia indicate? | Needle is in the nerve root |
| What are body habitus factors that contribute to nerve injuries? | Over/under- weight, muscular |
| For women, a BMI < ______ is associated with increased likelihood of ulnar nerve injury. | 22 |
| What pre-existing conditions increase the risk for nerve injuries? | PVD, peripheral neuropathy, smoking, subclinical ulnar nerve entrapment, thoracic outlet syndrome |
| A muscular body habitus is associated with what type of surgical injuries? | Ulnar nerve injury and compartment syndrome |
| Describe the difference between under- and over- weight patients and surgical injuries. | Underweight may develop decubiti or nerve damage d/t lack of adipose tissue over bone; overweight is d/t large tissue masses putting pressure on dependent body parts |
| Nerve injury and pre-existing neuropathies are more common in patients with what disease? | diabetes |
| What is the most common metabolic cause of spontaneous isolated femoral neuropathy? | diabetes |
| What are the most common upper extremity nerve injuries? | Ulnar (#1) and brachial plexus (#2) |
| What is the most common lower extremity nerve injury? | Common peroneal |
| Ulnar neuropathy is a well-known complication of what type of surgery? | cardiac |
| Elbow flexion compresses the ulnar nerve in what structure? | cubital tunnel |
| Elbow flexion stretches the cubital tunnel between what two bony structures? | Medial epicondyle, olecranon |
| Ulnar nerve injuries are more frequently associated with (males/females), especially over the age of ______. | Males; 50 |
| Identify the vertebrae of origin for the brachial plexus. | C5-C8, T1-T2 |
| STUDY SLIDE 19 | |
| STUDY SLIDE 21 | |
| The nerve roots merge to form what 3 structures? | Superior (upper), middle (middle), inferior (lower) trunks |
| What do the 3 nerve trunks subdivide into? | 3 anterior and 3 posterior divisions |
| The 3 anterior and 3 posterior divisions run (anterior/posterior) to the clavicle. | posterior |
| The patient is vulnerable to brachial plexus injuries if the arms are _______, the shoulders are _________, or the head is ________. | abducted, depressed, rotated |
| STUDY SLIDE 23 | |
| (Supination/Pronation) increases pressure over the ulnar nerve. | pronation |
| What are the positioning recommendations to prevent ulnar nerve injury in anesthetized patients? | Use of padding, supinate arms, abduction <90 degrees with armboards |
| What are 5 different positioning devices? | Straps, stirrups, shoulder braces, arm boards, axillary rolls |
| Table straps or leg holding devices are associated with what type of nerve injury? | Lateral femoral cutaneous nerve (thigh) |
| Common peroneal nerve injury has been attributed to the use of what type of positioning device? | Crutch stirrups |
| Brachial plexus injuries have been reported with what two positioning devices? | Falling armboards, shoulder braces in steep T-burg |
| Leg holding devices for arthroscopy is associated with what type of nerve injury? | Lateral femoral cutaneous nerve |
| What is the purpose of repositioning and massaging the head in the supine patient? | Prevents alopecia of the occiput |
| What is the cause of backaches in the supine position and what can be done to prevent it? | Caused by abolition of lumbosacral curve; place folded sheet or bag of IVF under the lumbar spine |
| Crossed legs in the supine position may lead to what two nerve injuries and in which legs? | Damage to the superficial peroneal nerve in the dependent leg and damage to the sural nerve in the superior |
| What devices can evenly distribute body weight following lengthy procedures? | Gel pads or mattresses |
| Armboards should be angled less than _________ degrees. | 90 |
| What direction should the thumbs be pointed if the patient's arms are resting at the sides? | up |
| What two respiratory factors are decreased in the supine position? | FRC and chest wall muscle tone |
| What does bending the hips and knees improve for the supine patient? | venous return |
| Which surgical position produces the least amount of physiologic changes? | supine |
| What are 4 drawbacks to T-burg? | Doesn’t predictably improve CO in low BP/low volume patients, decreased stroke volume from viscera pressing on the heart, compresses lung bases, may increase ICP |
| What benefit does the prone position have over the sitting position in its use for intracranial procedures? | Less risk for VAE |
| What are the CV effects of the prone position and why? | Compression of the inferior vena cava and aorta d/t cephalad displacement of the diaphragm |
| What major vessels are compressed in the prone position? | Inferior vena cava and aorta |
| Placing padding underneath the shoulders of a prone patient prevents stretching of the _________ nerve. | Brachial plexus |
| Placing padding between the elbow and the armboard in the prone patient helps prevent ____________ nerve damage. | Ulnar |
| Pressure on the abdomen from the prone position may cause what 3 complications? | Impede venous return, increase venous pressures, inhibit diaphragmatic movement |
| In reference to spinal cord surgery, what is the benefit of positioning devices that allow for the abdomen to hang freely? | Decreased inferior vena cava pressures, which prevents engorgement of spinal venous plexuses (epidural veins) |
| The ______ Table improves diaphragmatic excursion in the prone position. | Jackson |
| How does rotation of the head negatively affect blood flow? | May obstruct jugular venous drainage |
| What devices can be used to support the had of the prone patient w/cervical arthritis? | Prone pillow or Mayfield headrest |
| What ocular complications are associated with the prone position? | Corneal abrasions and POVL |
| In the absence of a Jackson Table, what can be used to relieve abdominal pressure in the prone patient? | Chest rolls placed from clavicle to iliac crest |
| What are two variations of prone positioning? | Jack-knife, kneeling |
| What surgical position is associated with the most significant circulatory and ventilatory effects? | Lateral decubitus |
| Compression of which vessel may occur with lateral decubitus, especially in conjunction with a kidney rest? | Inferior vena cava |
| Lateral decubitus is used for surgeries involving what areas of the body? | Thorax and kidneys |
| What effect does lateral decubitus have on the lungs? | Underventilation of dependent lung and increased compliance of nondependent lung |
| What structures compress the dependent lung in lateral decubitus? | Abdominal contents and mediastinum |
| Lateral decubitus positioning may lead to _____ mismatch, with an increase in bloodflow to the (dependent/nondependent) lung. | V/Q; dependent |
| What should periodically be checked in the lateral decubitus patient? | Radial artery; pulse Ox on dependent hand can also assess perfusion |
| What are the angles for true and modified sitting positions? | 90=true, 45=modified |
| What are the CV changes associated with the sitting position? | Decreased CO, CVP, PAWP |
| How much does MAP decrease with sitting position? | 0.75mmHg per cm of elevation |
| What is the most serious complication with the sitting position and why? | VAE b/c of negative pressure gradient b/w R atrium and veins and the operative site |
| The supine and lithotomy both cause _______ displacement of the diaphragm and viscera. | cephalad |
| What are the principle nerve injuries of the lithotomy position? | Sciatic, common peroneal, femoral, saphenous, obturator |
| What are three steps to take in caring for the patient in lithotomy? | Padding b/w metal brace and patient’s leg, elevate and lower both legs simultaneously, thigh flexion of no more than 90 degrees prior to lateral rotation of stirrups |
| Prolonged lithotomy of > _____ hrs may result in compartment syndrome. | 4 |
| When are peripheral nerve injuries more likely to occur during procedures requiring what type of anesthesia? | GA |
| What are the usual causes of post-op neuropathy? | Position-related compression or stretch |
| What are types of studies that can be done with a peripheral nerve injury? | Conduction, velocity, and EMG studies |
| Acute injury will appear _______ days after the onset of symptoms. | 18-21 |
| How long does it take to recovery from a peripheral nerve injury? | 3-12mos |
| What is the most common post-op neuropathy? | Ulnar nerve injury |
| What is the prevalence of ulnar nerve injury after cardiac surgery? | 38% |
| Bending the elbow narrows the _________ and compresses the _______ nerve. | cubital tunnel; ulnar |
| Bending the elbow narrows the _________ and compresses the _______ nerve. Cubital tunnel; ulnar | supinated; up |
| How does ulnar nerve injury manifest itself? | 1)inability to abduct or oppose the fifth finger 2)diminished sensation over medial one and half fingers 3)atrophy of intrinsic muscles of the hand |
| Claw hand is associated with what type of nerve injury? | Ulnar |
| What are two reasons the brachial plexus is prone to injury? | Long superficial axillary course and proximity to movable bony structures |
| Name two bony structures that may cause brachial plexus injury? | Clavicle and humerus |
| What is the second most commonly injured nerve in the upper body? | brachial plexus |
| Shoulder braces may compress the brachial plexus between which bones? | Clavicle and first rib |
| A compression injury of the brachial plexus may occur if a shoulder brace is not placed over the _______ joint. | acromioclavicular |
| Which surgical position has the highest prevalence for brachial plexus injuries? | Lateral decubitus |
| How do sternal retractors affect movement of the clavicle and 1st rib? | Clavicle moves posterior, 1st rib moves up |
| What steps should be taken in cardiac surgery to minimize brachial plexus injury? | Caudad placement of retractors and avoidance of prolonged and asymmetric chest retraction |
| Where should an axillary roll be placed in order to prevent brachial plexus injury? | Slightly caudad, not directly underneath the axilla |
| The radial nerve may be injured if pressure is applied to it while it transverses the ________. | Spiral groove of the humerus |
| What are the manifestations of radial nerve injury? (3) | Wrist drop, weakened thumb abduction, decreased sensation over the dorsal surface of the thumb, 1st and 2nd fingers |
| The median nerve runs over what important anatomical feature? | Antecubital fossa |
| What are the primary causes of median nerve injury? | IV placement or extravasation |
| Sodium pentothal (is/is not) caustic to veins. | is |
| “Ape hand” deformity is associated with what nerve injury? | Median |
| What positions are the thumb and index finger arrested in with median nerve injury? | Adduction and hyperextension |
| What thumb functions are lost with median nerve injury? | Opposition and flexion |
| Where should an axillary roll be placed in order to prevent brachial plexus injury? | Slightly caudad, not directly underneath the axilla |
| The radial nerve may be injured if pressure is applied to it while it transverses the ________. | Spiral groove of the humerus |
| What are the manifestations of radial nerve injury? (3) | Wrist drop, weakened thumb abduction, decreased sensation over the dorsal surface of the thumb, 1st and 2nd fingers |
| The median nerve runs over what important anatomical feature? | Antecubital fossa |
| What are the primary causes of median nerve injury? | IV placement or extravasation |
| Sodium pentothal (is/is not) caustic to veins. | is |
| “Ape hand” deformity is associated with what nerve injury? | Median |
| What positions are the thumb and index finger arrested in with median nerve injury? | Adduction and hyperextension |
| What thumb functions are lost with median nerve injury? | Opposition and flexion |
| Where does decreased sensation occur with median nerve injuries? | Palmar aspect of the lateral 3 ½ fingers |
| Compression injury of the sciatic nerve occurs due to the nerve passing under the _______ muscle. | Piriformis |
| What are the two points of fixation of the sciatic nerve and what two movements increases the distance b/w these points? | Sciatic notch and fibula; external rotation of the leg or knee extension |
| What is the longest and widest single nerve of the human body? | sciatic |
| What are the two branches of the sciatic nerve? | Tibial and common peroneal |
| Sciatic nerve injury occurs due to improper placement of the patient in what surgical position? | lithotomy |
| IM injection into the ______ could cause sciatic nerve injury. | buttocks |
| IM injections in the OR should be placed in the ________ aspect of the _______. | lateral; thigh |
| How is sciatic nerve injury manifested? | Weakness of all skeletal muscles below the knee; diminished sensation over the lateral half of the leg and almost all of the foot |
| What does damage to the common peroneal nerve reflect? | Compression between the head of the fibula and metal brace in the lithotomy position |
| What is the most frequently injured nerve in the lower body? | Common peroneal |
| How does injury to the common peroneal nerve manifest? | Foot drop, loss of dorsal extension of the toes, inability to evert the foot v |
| Foot drop is indicative of nerve injury to the ________. | common peroneal nerve |
| Anterior tibial nerve injury may manifest post-op if the feet are ___________ for extended periods of time. | plantar flexed |
| Where should a roll be placed for patients in the sitting position to prevent anterior tibial nerve injury? | Under the anterior aspect of the ankle to maintain extension |
| What are two possible causes of a femoral nerve injury? | Compression by retractor blade (laparotomy) or by excessive angulation (lithotomy) |
| What are the 3 manifestations of a femoral nerve injury? | Decreased knee jerk, loss of hip flexion, loss of knee extension |
| Where does decreased sensation occur with a femoral nerve injury? | Superior aspect of the thigh, medial and anterior medial side of the leg |
| A pelvic fracture may cause _________ nerve injury. | femoral |
| What does the saphenous vein branch from? | femoral nerve |
| Where does pain occur with a saphenous nerve injury? | Medial knee and leg pain |
| Compression of the saphenous nerve against the _______ can result in injury. | medial tibial condyle |
| How does obturator nerve injury manifest? | Loss of leg adduction, decreased sensation over medial thigh |
| In what scenarios can an obturator nerve injury occur? | Difficult forceps delivery, excessive flexion of thigh to groin |
| Pressure necrosis of the groin can occur with what orthopedic table? | Chick Table (hip surgery) |
| What are high-risk surgeries for POVL? | Cardiac and prone spinal surgeries |
| The retina supplies axons to the _____ nerve. | optic |
| What are the 4 divisions of the optic chiasm? | Intraocular, intraorbital, intracannicular, intracranial |
| Where do the retina and optic nerves receive their blood supply? | Through the central retinal and ciliary arteries |
| Arteries that supply the retina and optic nerve arise from the ______. | Internal carotid |
| What important function do retinal and ciliary arteries lack? | Autoregulation in the presence of hypoperfusion |
| What are two pre-existing conditions that affect autoregulation and increase the risk for POVL? | DM and HTN |
| Thrombosis of the central retinal artery, which may lead to permanent blindness, can be caused by what factors? | Prone position, deliberate/accidental hypotension, increased intraocular pressure |
| Trauma of the appendages most often occurs with the _____. | Fingers |
| What is the most likely cause of trauma to the fingers in patient positioning? | Foot of the table is returned to horizontal position in lithotomy |
| Face masks can place pressure on the _________ branch of the facial nerve. | Buccal |
| What does injury to the buccal branch of the facial nerve result in? | Paresthesia of the orbicularis oris muscle |
| What nerve can be compressed by the ETT and how does this injury manifest? | Suborbital |
| Decreased sensation over the forehead and pain in the eye may be due to injury of what nerve? | Suborbital |
| Compression of what part of the mandible can cause facial nerve damage? | Ascending ramus |
Created by:
philip.truong
Popular Nursing sets