atientPositionDuringAnesthesia麻醉期間病人的位置課件

1、atientPositionDuringAnesthesia麻醉期間病人的位置Patient Position During AnesthesiaByDavid Roy Godden CRNA, MSNatientPositionDuringAnesthesia麻醉期間病人的位置Lecture Objectives Gain an understanding of safe positioning basics Identify the potential nerve injuries from mask ventilation State the correct hand and arm p

2、ositioning for supine, lateral decubitus and prone positions. Be able to recite the potential nerve injuries of each patient position. Identify the complications of the sitting position.atientPositionDuringAnesthesia麻醉期間病人的位置Objectives Cont Define and understand the hemodynamics of each patient posi

3、tion. Understand and be able to verbalize - that means know thoroughly - the respiratory and autonomic responses of differing patient positions while awake and under general anesthesia. Discuss Post Operative Visual Loss (POVL) Case Study: Complications of Prone position atientPositionDuringAnesthes

4、ia麻醉期間病人的位置Look for Key Points Positioning is often a compromise between what is required for surgical exposure and patient comfort! Do not place sedated or anesthetized patients in positions that they are not comfortable with when awake. If in doubt about patients safety have the patient assume the

5、 position on the OR table before induction to see how they tolerate the position. Patient positioning is the joint responsibility of OR Nursing, Anesthesia and Surgery. All three individuals and groups that represent them will be held liable if errors in positioning cause patient harm. Document!atie

6、ntPositionDuringAnesthesia麻醉期間病人的位置Documentation of Positioning The only thing that represents what was done in the operating room in a court of law is your testimony and your documentation. How much do you think you can remember from one case to the next and how much of your “story” will the court

7、officers “believe” without your careful documentation in the anesthesia record? What to document? Pre-operative patient limitations in movement strength and nerve abnormalities. Does the patient have numbness tingling or loss of sensation to any extremity pre-operatively? Does the patient have foot

8、drop?atientPositionDuringAnesthesia麻醉期間病人的位置atientPositionDuringAnesthesia麻醉期間病人的位置Mask Injuries Potential for corneal abrasion is always present when mask ventilating patients. Face straps which are tight across the patients face with prolonged use may cause injury to the facial nerve. What are the

9、 five branches of the facial nerve remembering the mnemonic, “Two zebras bit my cat” The bucal branch is most likely injured with a face strap compression. Temporal Zygomatic Bucal Mandibular cervicalatientPositionDuringAnesthesia麻醉期間病人的位置Dorsal Decubitus Positions Gravity effects blood flow and muc

10、h of pulmonary mechanics. Humans, giraffes and dinosaurs share one thing in common. What is it? In the supine position gravity equalizes blood pressure gradients between heart and arteries in the head and lower extremitiesatientPositionDuringAnesthesia麻醉期間病人的位置Correct Anatomical Position What is the

11、 ventral surface? What is the dorsal surface Note: Dorsal to dorsal and ventral to ventralatientPositionDuringAnesthesia麻醉期間病人的位置Dorsal Decubitus Positions Head tilt either upwards or downwards will change the pressure gradients. A movement of 2.5 cm in vertical elevation will change the blood press

12、ure 2 mm Hg. In the parturient an IV bag under the right hip will shift the gravid uterus to the left. Have you heard of Aorto-caval syndrome?atientPositionDuringAnesthesia麻醉期間病人的位置Hand positioning Lying at attention requires correct arm and hand position to minimize the chances of nerve injuries. A

13、rms are to be less than 90 degrees lateralized from the thorax in correct anatomical position looking at the shoulders. This will minimize the chance of brachial plexus injury. Arms at side of body must be in correct dorsal to dorsal alignment with the arms supinated OR palms toward the body is OK a

14、s well. The ulnar nerve passes close to the surface of the skin in the medial condyle of the elbow. The olectranon will protect the nerve if placed downwards. Radial nerve injury is possible with ether screen compression to the lateral arm. Radial nerve injury may result in wrist drop.atientPosition

15、DuringAnesthesia麻醉期間病人的位置What is Supination Correct anatomical position is lying at attention or Palms are ventral surface so ventral to ventral Dorsal to dorsal mean back of hands to back.atientPositionDuringAnesthesia麻醉期間病人的位置Head down things Lowering the head will increase the pressure in the cer

16、ebral veins which may lead to vascular head ache, congestion of nasal mucosa and conjunctiva in healthy individuals. This may lead to edema in the larynx as well. The sclera is the window to the vocal cords! Head lowering in patients with intra-cranial lesions will exacerbate the condition raising C

17、PP and ICP (whats the formula for this?)atientPositionDuringAnesthesia麻醉期間病人的位置Autonomic function Aortic arch and carotid sinus house barorecetors that are part of the bodies homeostatic mechanism to maintain blood pressure within a narrow range. Increased firing of the receptors when stretched from

18、 an increase in blood pressure is part of a negative feed back loop. The increased firing from the baroreceptors enhances the parasympathetic nervous system lowering blood pressure and slowing the heart rate. Remember this! What are the nerves responsible for the baroreceptor reflexes?atientPosition

19、DuringAnesthesia麻醉期間病人的位置Respiratory Effects Respiratory mechanics will suffer in the head down position how? Review Wests zones of the lung. Normal excursion of the diaphragm in head down position is impeded and increase the work of breathing. In the paralyzed mechanically ventilated patient, highe

20、r peak pressures will be required for adequate ventilation. Supine patients develop VQ mismatch due to vascular congestion in the dorsal portions of the lung and changes in compliance. The dorsal lung (now zone 3) will have reduced compliance. Passive ventilation tends to distribute gas preferential

21、ly to the more easily distensible substernal units where pulmonary blood flow volume is less (Barish, 2006).atientPositionDuringAnesthesia麻醉期間病人的位置More Respiratory things To prevent development of significant V-Q imbalance during use of controlled ventilation, tidal volumes must be used that are gre

22、ater than the average amount that is sufficient for the spontaneously breathing conscious pt. Compare and contrast the awake spontaneously breathing pt and the paralyzed mechanically ventilated pt in the lateral position. How would you attempt to decrease Peak pressures during mechanical ventilation

23、 in the paralyzed anesthetized patient? Hint: deepen anesthetic, muscle relaxation, decrease Vt and increase Rate, change I:E ratio from 1:2 to 1:1.5. Consider Pressure Control ventilation due to its decelerating waveform.atientPositionDuringAnesthesia麻醉期間病人的位置Variations in the Dorsal Decubitus Posi

24、tion Supine otherwise known as lying at attention. Places strain on lower segments of lumbar spine. Lawn chair is a more physiologically tolerated position due to decreased stretch on lower back. Frog leg (heal to heal with lateralization of knees) for peroneal examinations may place excessive stret

25、ch on back, hips and pelvic structures. Pad under knees. Complications of excessive stretch may include 1) postoperative hip and back pain; 2) dislocated hip or fracture of an osteoporotic femur; 3) obturator nerve injury.atientPositionDuringAnesthesia麻醉期間病人的位置Complications of Dorsal Decubitus Press

26、ure Alopecia due to prolonged compression of hair follicles. Most alopecia occurs between the 3rd and 28th postoperative day while re-growth usually occurs within 3 months (Barish, 2006). Placement of gel pad or donut under head is worthwhile. Frequent repositioning of the head is warranted.atientPo

27、sitionDuringAnesthesia麻醉期間病人的位置Complications of Dorsal Decubitus Pressure point reactions occur when bony prominences are unsupported for prolonged periods. Hypothermia and hypotension enhance the ischemic process. The heals, elbows and sacrum should be gel padded. NOTE: There are no studies proving

28、 decreased incidence of peripheral neuropathies due to gel padding. Back pain due to loss of lordosis. Lawn chair position best.atientPositionDuringAnesthesia麻醉期間病人的位置Lithotomy Position Lithotomy position traditionally has been used during gynecologic and urologic surgery. The hips are flexed 80 to

29、100 degrees and the hips are abducted 30 to 45 degrees from midline. Hip flexion greater than 90 degrees may cause stretch of the inguinal ligaments and impinge the lateral femoral cutaneous nerves which pass through the inguinal ligament which leads to numbness in the lateral thigh. The legs should

30、 be moved into and out of position simultaneously. The knees are brought to midline and the legs slowly unflexed to the supine position at the end of the surgical procedure.atientPositionDuringAnesthesia麻醉期間病人的位置Complications in Lithotomy Leg elevation causes increase in venous return and transient

31、rise in CO and ICP. Alterations in pre-Load is most responsible for hemodynamic changes during anesthesia. Abdominal viscera is displaced cephalad decreasing Vt and increasing peak pressures. Back pain from loss of lordotic curvature of spine in lithotomy position.atientPositionDuringAnesthesia麻醉期間病

32、人的位置Lithotomy Complications DANGER to fingers. Watch carefully when hands are tucked and raising or lowering foot board. Injury to the common peroneal nerve. This is the MOST COMMOM nerve injury to the lower extremities accounting for 78% of all lower extremity motor neuropathies caused by compressi

33、on of the nerve between the lateral head of the fibula and “candy cane” bar stirrups. Duration of surgery greater than 2 hours is a predictor of increased incidence of lower extremity neuropathy.atientPositionDuringAnesthesia麻醉期間病人的位置More Complications of Lithotomy Positioning Compartment syndrome i

34、s a rare complication but occurs in lithotomy position due to inadequate perfusion to the raised extremity. Ischemia, edema and the possibility of rhabdomyolysis occurs from the increased pressure in the fascial compartment. For you number heads, compartment syndrome occurred in about 1 in a million

35、 for patients in supine position and about 1 in 9,000 for pts in lithotomy position. What do you think about lithotomy? Danger!atientPositionDuringAnesthesia麻醉期間病人的位置Lateral Decubitus position Lateral decubitus position is used for surgeries on thorax, retroperitoneal structures or hip. V-Q mismatch

36、 increases due to gravitational forces. Perfusion is greatest in dependent structures or down lung while ventilation is better in nondependent lung. Use of “Chest Roll” incidentally misnamed axillary roll. The presence of the chest roll is to prevent compression injury to the brachial plexus. Monito

37、r the pulse in the dependent arm please.atientPositionDuringAnesthesia麻醉期間病人的位置Lateral Decubitus position Non dependent arm is “air planed” or supported with pillows and not allowed to be abducted greater than 90 degrees. Place pillow between knees with dependent leg flexed. Pressure points include

38、acromion process, iliac crest, greater trochanter, peroneal nerve and lateral maleolus.atientPositionDuringAnesthesia麻醉期間病人的位置Complications of Lateral Decubitus Eye and ear injuries. Make sure that downside ear and eye are “free” from pressure. Use a donut roll for the ear. Use of the Opti-guard or

39、eye guard is considered useful in lateral positions. Neck flexion needs to be avoided. Position neck midline with supporting towels.atientPositionDuringAnesthesia麻醉期間病人的位置Complications of Lateral Decubitus Suprascapular nerve stretch from the circumduction of the dependent shoulder. The chest roll s

40、hould prevent this. Long thoracic nerve injury from lateral decubitus position has been documented. Winging of the scapula is the typical clinical sign. The serratus anterior muscle is solely supplied by the long thoracic nerve which branches from C5 C6 and C7.atientPositionDuringAnesthesia麻醉期間病人的位置

41、Kidney Position Kidney position is a flexed lateral decubitus position where the table is flexed to “open up” the lateral structures for surgical exposure. Flex point should be under iliac crest not rib cage. Stabilize the patient to prevent movement and shifts caudad on the table so that the kidney

42、 rest may not relocated itself into the downside flank. Ventilation issues again may occur due to dependent lung compromise and V-Q mismatching.atientPositionDuringAnesthesia麻醉期間病人的位置Prone Positioning Prone position is primarily used for surgical access to posterior aspect of the spine, posterior fo

43、ssa of skull, buttocks and perirectal areas or posterior portions of the lower extremities. Prone positioning requires planning. Induction and intubation of the trachea is accomplished while patient is supine on stretcher. IV access is performed as well as arterial catheter placement prior to turnin

44、g prone on operating room table. Would you consider use of LMA or extubation in the prone position?atientPositionDuringAnesthesia麻醉期間病人的位置Supporting devices for Prone The head is supported usually midline. Mayfield tongs are used for craniotomy cases in the prone position. At LAC we use the Prone Vi

45、ew with a mirror to see the facial structures while the patient is prone. Turning the head to the side may be used but lateral rotation of the neck may compromise carotid or vertebral arterial blood flow and may restrict venous drainage. Eye protection is required.atientPositionDuringAnesthesia麻醉期間病

46、人的位置Supporting devices for Prone Support of the thorax with firm bolsters which are placed under the patients sides from clavical to iliac crest. This allows the belly to hang free and increases ventilation while preventing aorto-caval compression. Breasts are placed medial and cephalad while genita

47、ls are insured to be non compressed.atientPositionDuringAnesthesia麻醉期間病人的位置Arm placement in Prone pts Placement of the arms is either at the sides of the patient or forward alongside the head on padded arm boards. Padding of the elbow is required. Abduction of the arms should be limited to less than

48、 90 degrees to prevent excessive stretch of the brachial plexus. Ankles may be supported with a bend in the knees to reduce stretch to the lumbar spine. Calf compression stockings are routinely used to prevent venous stasis or blood pooling with reduction in DVT.atientPositionDuringAnesthesia麻醉期間病人的

49、位置Complications of Prone Position Prone position is one of the more challenging positions to the anesthetist. Eye and ear injuries are more common in this position. Eye protection with Opti-guard is warranted. Scleral edema is common in prone patients. Blindness. Permanent loss of vision can occur a

50、fter nonocular surgical procedures especially in patient in the prone position! Spine surgery with its blood loss, hypotension and anemia may all conspire together to produce optic nerve ischemia.atientPositionDuringAnesthesia麻醉期間病人的位置Additional Prone Problems Neck injuries due to misalignment. Brac

51、hial plexus injuries due to excessive stretch or misalignment of shoulders. Breast or genital injuries causing pain or dysfunction. Not good. Medial placement of breasts is recommended. Abdominal compression injuries may be alleviated with the use of bolsters.atientPositionDuringAnesthesia麻醉期間病人的位置P

52、rone Problems Knee injuries are especially prevalent in the obese or in those with pathologic conditions of the knees preoperatively. Document and pad the knees heavily. Injury to the dorsum of the feet is also possible. Thoracic Outlet syndrome. How do you test for it? Did you forget about POVL in

53、the Prone position?atientPositionDuringAnesthesia麻醉期間病人的位置Sitting Position See attached article in anesthesia patient safety newsletter. Beach chair position may cause decreased cerebral perfusion, CVA, and brain death - really. Apsf Newsletter article READ IT! Major risk of sitting position is hypo

54、tension. Sitting position and the risk of AIR EMBOLIS.atientPositionDuringAnesthesia麻醉期間病人的位置More Sitting Position Sitting position is often used for outpatient shoulder surgery and posterior fossa approaches Why! When other positions are less dangerous! Hemodynamic effects can be dramatic. Pooling

55、of blood in the lower part of the body and the subsequent decrease in cerebral perfusion. Remember the 2 mm Hg rule? There will be a question about this Hint Hint. Often in shoulder surgery while in the sitting position the surgeon “requests” hypotension really its true!atientPositionDuringAnesthesi

56、a麻醉期間病人的位置Complications of Sitting Position Potential complications due to flexion of the neck which can impede both arterial and venous blood flow through the neck. Flexion of the endotrachial tube may lead to excessive pressure on the tongue leading to macroglossia. Neck flexion may be measured an

57、d kept to acceptable limits with two fingerbreadths distance between chin and sternum. Venous air embolism is a serious complication of sitting position and the reason for its rare use.atientPositionDuringAnesthesia麻醉期間病人的位置Venous Air Embolism This life threatening condition may occur any time a sur

58、gical site is above the level of the heart. There are no valves in the cerebral venous circulation and the risk of venous air embolism is constant in the sitting position when the operative site evolves the posterior fossa or may occur in spinal surgery when prone! Remember this! Venous air embolism

59、 may be manifested as cardiac dysrhythmias, arterial oxygen desaturation, pulmonary hypertension or frank cardiac arrest. Actions to take if you suspect an air embolism is to ask the surgeons to flood the field with saline and to apply bone wax to boney edges. For further discussion refer to your ne

60、uro lecture.atientPositionDuringAnesthesia麻醉期間病人的位置Overview of Nerve injuries The Closed Claims Project conducted by the ASA evaluated adverse anesthetic outcomes in 1990. Ulnar neuropathy remains the MOST frequent (28%) of all nerve injuries followed by brachial plexus (20%). Etiology of peripheral