Anesthesia And Positioning

ANESTHESIA AND POSITIONING by: JOVEN A. OCCEÑA, MD. Anesthesia Chief Resident DAVAO REGIONAL HOSPITAL

ANESTHESIA

OBJECTIVES

 CONSIDERATIONS: 1. Quality 2. Safety 3. Efficiency 4. Cost of drugs 5. Equipment

 Anesthetic should: 1. have a rapid and smooth onset of action 2. produce intraoperative amnesia and analgesia 3. good surgical conditions with a short recovery period 4. no side effects.

 Standard intraoperative monitoring equipment includes: A. precordial stethoscope B. electrocardiogram (ECG) C. blood pressure cuff D. pulse oximeter E. capnograph

Several factors have to be taken into consideration: 1. The technique should anesthetize not only the operative field but also all the areas involved in the surgery (e.g., site of tourniquet placement, sites where skin or bone grafts are to be taken)

Several factors have to be taken into consideration: 2. The adequacy of the duration of the sensory block with the expected duration of postoperative pain 3. The physical condition of the patient

Several factors have to be taken into consideration: 4. The local conditions at the site of puncture 5. The suitability of the position required for performing the block according to the lesions and/or the physical condition of the child

Several factors have to be taken into consideration: 6. The similar importance of anesthetic and surgical techniques (under normal conditions, central blocks have to be avoided for minor surgery) 7. The experience of the anesthesiologist

General Anesthesia  General anesthesia remains the most widely used anesthetic technique because of its popularity with patients, surgeons, and anesthesiologists  Anesthesiologist must consider: 1. the recovery characteristics of the anesthetics 2. the management of postoperative pain and nausea/vomiting when making the anesthesia plan.

General Anesthesia      

BENZODIAZEPINES OPIOIDS MUSCLE RELAXANT (non-depolarizing) LIDOCAINE BARBITURATES MUSCLE RELAXANT (depolarizing) – intubating dose

General Anesthesia  INGALED ANESTHETICS 1. HALOTHANE 2. ISOFLURANE 3. ENFLURANE 4. DESFLURANE 5. SEVOFLURANE 6. METHOXYFLURANE

RATIONALE FOR THE USE OF EPIDURAL AND SPINAL ANESTHESIA 1. Metabolic and endocrine alterations 2. Blood loss 3. Thromboembolic complications 4. Cardiopulmonary complications  Continuous epidural analgesia for postoperative pain relief

ANATOMY Bony structures Ligaments Epidural space – located between the ligamentum flavum and the dura mater Subdural space Subarachnoid space

PATIENT EVALUATION AND PREPARATION FOR EPIDURAL AND SPINAL ANESTHESIA  Physical examination of the back and history of back problems  Coagulation profile  Explanation of technique and perceived advantages  Description of the forms of sedation available  Tailor preoperative medication to level of anxiety and need for analgesia

CONTRAINDICATIONS FOR EPIDURAL AND SPINAL ANESTHESIA ABSOLUTE CONTRAINDICATIONS 1. Patient refusal 2. Infection at the puncture site 3. Uncorrected hypovolemia 4. Severe coagulation abnormalities 5. Anatomic abnormalities

CONTRAINDICATIONS FOR EPIDURAL AND SPINAL ANESTHESIA RELATIVE CONTRAINDICATIONS 2. Bacteremia 3. Preexisting neurologic disorders (multiple sclerosis) 4. Minidose heparin

TECHNICAL ASPECTS LANDMARK:

VERTEBRAL SPINAL PROCESSES (MIDLINE) ILIAC CREST ( A LINE DRAWN BETWEEN THE CRESTS CROSSES L4)

EPIDURAL ANESTHESIA  17 or 18 gauge tuohy needle (curved Huber point)  Loss of resistance technique  Catheter placement Test dose = 3-4cc local anesthetic + 1:200,000 epinephrine

SPINAL ANESTHESIA  Midline approach  Paramedian or lateral approach  The Taylor approach  Continuous spinal anesthesia

PHYSIOLOGIC EFFECTS OF SPINAL AND EPIDURAL ANESTHESIA A. Spinal anesthesia 1. Sympathetic nervous system blockade 2. Cardiovascular system a) Bradycardia b) Venodilation c) Decreased blood pressure

PHYSIOLOGIC EFFECTS OF SPINAL AND EPIDURAL ANESTHESIA A. Spinal anesthesia 3. Respiratory system 4. Renal system 5. Gastrointestinal system

PHYSIOLOGIC EFFECTS OF SPINAL AND EPIDURAL ANESTHESIA B. Epidural anesthesia 1. Hemodynamic effects a. Level of anesthesia (above T5) b. Systemic absorption of local anesthetic c. Inclusion of epinephrine (B1 and B2 effects) d. Intravascular fluid volume e. Cardiovascualr status of the patient 2. Effects on regional blood flow

PHARMACOLOGIC CONSIDERATIONS B. Spinal anesthesia 1. Selection of a specific local anesthetic A. Hyperbaric lidocaine B. Hyperbaric tetracaine C. Isobaric bupivacaine

PHARMACOLOGIC CONSIDERATIONS B. Spinal anesthesia 2. Factors that influence distribution of local anesthetics in the CSF A. Baricity of the local anesthetic solution B. Shape of the spinal canal C. Position of the patient D. Vasoconstrictors

B. Epidural anesthesia 1. The quality of epidural anesthesia is determined by several factors: A. Local anesthetic selected B. Mass of the drug injected C. Addition of epinephrine D. Site but not speed of injection or patient position E. Patients >40 yrs of age F. Pregnancy

COMPLICATIONS OF SPINAL AND EPIDURAL ANESTHESIA SPINAL 1. Hypotension 2. Postdural puncture headache i. Postural component ii. Frontal or occipital iii. Tinnitus iv. Diplopia v. Young females vi. Use of large gauge needle

COMPLICATIONS OF SPINAL AND EPIDURAL ANESTHESIA SPINAL

4.

3. Extensive spread of spinal anesthesia i. Agitation ii. Hypotension iii. Nausea iv. Absent intercostal muscle function v. Inadequate air movement to generate an audible voice Backache 5. Major neurologic injury or infection

COMPLICATIONS OF SPINAL AND EPIDURAL ANESTHESIA EPIDURAL

1. Toxicity due to local anesthetics i. Site of injection ii. Total dose iii.Vasoconstrictor iv.Pharmacologic profile of local anesthetic

COMPLICATIONS OF SPINAL AND EPIDURAL ANESTHESIA EPIDURAL

2. Technique related complications: 1) Hypotension 2) Accidental Subdural or subarachnoid injection 3) Dural puncture and postdural headache 4) Neural damage 5) Catheter complications

POSITIONING THE SURGICAL PATIENTS

OBJECTIVES

PROPER LITHOTOMY POSITION: minimal external rotation of legs, thighs minimally flexed toward abdomen, symmetrical position of legs. Protective paddings not shown.

CLASSIC PRONE POSITION with arms extended next to head (A), or alongside torso (B). Chest roll placed below clavicle and pillow under iliac crest to along abdomen to hang free. The table is flexed to a variable degree depending on the lumbar lordosis and the needs of the surgeon. With flexion, a subgluteal anchor is needed to prevent caudal slippage of the patient.

CLASSIC PRONE POSITION

The ANDREWS FRAME, which supports the chest and buttocks, with the knees padded. The knees are never flexed more than 90 degrees on the thighs.

ANDREWS FRAME

Methods of avoiding excessive turning of the head in the prone position, A, B, and C are acceptable. Extreme rotation of the neck (D) may be dangerous in patients with cervical spine disease or cerebrovascular disease. The eyes themselves must be free from pressure, since pressure on the globe may reduce flow in the retinal vessels enough to produce permanent retinal blindness.

NEUROSURGICAL SITTING POSITION. The legs are slightly flexed and raised to the level of the heart. The feet are padded to maintained a dorsiflexed position. The sciatic nerve is protected by gluteal padding. The framed of the head holder is clamped to the back section of the table so that the patient head’s head can be lowered in case of air embolism.

NEUROSURGICAL SITTING POSITION

The RIGHT LATERAL DECUBITUS POSITION. (Above) inadequate padding and improper head position. (Below) Padding over bony prominence, chest roll to protect neurovascular bundle in the axilla, and proper alignment of cervical spine. The lower leg is flexed to stabilized the patient.

inadequate padding and improper head position.

Padding over bony prominence, chest roll to protect neurovascular bundle in the axilla, and proper alignment of cervical spine

FLEXED LATERAL DECUBITUS POSITION. The point of flexion lies beneath the dependent iliac crest to minimize interference with the dependent lung and diaphragm.

FLEXED LATERAL DECUBITUS POSITION

The LAWN CHAIR POSITION with flexion of the hips, minimal knee flexion, and trunk section level.

LAWN CHAIR POSITION

Brachial plexus in relation to surrounding structures. (A) arm at side: 1. Brachial plexus. 2. Clavicle, 3. Coracoid process, and 4. Head of humerus. (B) arm at right angle. (C) arm hyperextended by shoulder brace, depresses scapula, streching brachial plexux beneath coracoid process and around humeral head.

Flexing, then raising of the legs for the lithotomy position

Holding the leg and stirrups for final positioning

Final lithotomy position showing the leg placement

Lithotomy position with less hip flexion for endoscopic procedures e.g. TURP

Lithotomy with hip flexion slightly greater than 90 degrees

Legs do not touch support poles

Straps use instead of stirrups

Risk to fingers when the lower portion of the operating table is lowered

The lateral position showing upper arm rest in position; axillary roll, which support the chest to free the axilla and 1 type of leg positioning

The lateral decubitus position for thoracotomy, showing more headward position of the arms to facilitate surgical exposure

Movement of the patient from the supine to lateral position

Movement of the patient from the supine to lateral position

Movement of the patient from the supine to lateral position

Movement of the patient from the supine to lateral position

The lateral oblique position ( threequarters prone). The axillary roll is placed under the chest, and the lower shoulder is brought forward to the edge of the bed or just slightly over the edge

Femoral neck fracture can be managed in the supine position on the fracture table

For midfemoral fracture, the patient is placed on the fracture table in the lateral position, with the legs spaced and positioned to allow xray at an angle in several planes

Lateral view of upright shoulder position. The endotracheal tube and head are secured to prevent movement and accidental extubation

Arrangement for surgery in the sitting position. The scrub nurse is to the right of the surgeon to place the instruments into the surgeon’s right hand. The entire left side of the patient is available for the anesthesiologist’s care

The patient is in semisitting position with the knees flexed slightly. The headrest support is fastened to the upper part of the table so that the head can be lowered without changing the relationship of the pinion head holder to the torso. Arms must be supported and buttocks padded.

The head can slip while in the horseshoe headrest, and pressure may develop in the eye owing to the weight of the head

GOOD DAY !!!