Orthopedic Surgery Flashcards
Acute myocardial infarction rate after Hip or knee arthroplasty
0.3 % - 1.8 %
Pulmonary hypertension
1) Pulmonary hypertension -resting mean pulmonary arterial pressure of 25 mm Hg
2) classified into five groups:
(1) patients with primary pulmonary arterial hypertension,
(2) patients with pulmonary hypertension due to left heart disease, (3) patients with pulmonary hypertension due to chronic lung disease and/or hypoxia,
(4) patients with chronic thromboembolic pulmonary hypertension, and (5) patients with unclear, mixed, or multifactorial reasons for pulmonary hypertension .
3) mortality after undergoing noncardiac surgery 3.5% - 18%
Preoperative characterization of frailty
1) weight loss
2) decreased grip strength
3) exhaustion
4) low physical activity
5) slowed walking speed
Arthropeasties and bleeding risk
1) arthroplasties: moderate risk of bleeding
whereas vertebrospinal surgery: high risk of bleeding.
2) aspirin should be discontinued 5 days before surgery and until 7 days after surgery in patients with a low- to moderate cardiovascular risk (e.g., in patients taking aspirin as a primary prophylaxis).
In patients with a high cardiovascular risk (e.g., patients with known coronary artery disease but an acute coronary syndrome >12 months preoperatively, drug-eluting stent >6 months, bare-metal stent >1 month, cardiac bypass surgery >6 weeks), aspirin can be continued during arthroplasty surgery.
very high cardiovascular risk to noncardiac surgery
1) acute coronary syndrome <12 months preoperatively,
2) drug-eluting stent <6 months,
3) bare-metal stent <1 month,
4) cardiac bypass surgery <6 weeks,
5) cerebrovascular accident <4 weeks);
elective orthopedic surgery in patients with end-stage renal disease (ESRD)
1) timing of preoperative and postoperative dialysis to avoid hypervolemia, hyperkalemia, and acidosis;
2) cardiovascular assessment and blood pressure control;
electrolyte management, anemia, drug metabolism, and the balance between thromboembolic complications and higher bleeding risk, both of which can be increased in patients with ESRD.
The main complications in hip replacement surgery
1) urinary tract infection,
2) deep vein thrombosis (DVT),
3)pneumonia,
4)superficial wound infection,
5)deep wound infection,
6)prosthesis failure,
7)pulmonary embolism,
8)myocardial infarction
9) peripheral nerve injury
Anesthetic Considerations for Patients With Rheumatoid Arthritis
1)Airway: Limited TMJ movement; Narrow glottis opening
2)Cervical spine: Atlantoaxial instability
3)Cardiac: Pericarditis; Pericardial fluid with tamponade physiology
4) Eyes Sjögren syndrome
5) Gastrointestinal: Gastric ulcers secondary to ASA or steroids
6) Pulmonary: Diffuse interstitial fibrosis
7) Renal: Renal insufficiency secondary to NSAIDs . י
Ankylosing spondylitis
1) Vertebral fractures may occur spontaneously or with minimal trauma; the cervical spine is a common site.
2) Cervical kyphosis may make direct laryngoscopy difficult or impossible, and temporomandibular joint disease may limit mouth opening
3) the incidence of epidural hematoma after neuraxial anesthesia is higher in ankylosing spondylitis patients.(increased incidence of traumatic needle placement, the prevalence of NSAID use, or narrowing of the epidural space that makes symptomatic spinal cord compression)
4) Inflammation and fibrosis of the ascending aorta and aortic root⇒ aortic insufficiency, and extension to the conduction⇒heart block or supraventricular arrhythmias.
5) elevated risk of atherosclerosis.
6) Pulmonary manifestations-restrictive lung disease due to kyphosis and chest wall rigidity , pulmonary fibrosis.
7) preoperative cardiopulmonary evaluation: electrocardiography, echocardiography, and/or pulmonary function testing
Achondroplasia
1) disproportionately short stature, lumbar lordosis, large head, midface hypoplasia, short hands, and normal cognitive development. Hight risk of tibial bowing and spinal stenosis.
2) airway management: midface hypoplasia with a pharynx that is small in proportion to the tonsils, adenoids, and tongue makes these patients prone to upper airway obstruction and may hinder direct laryngoscopy.
A flat nasal bridge and large mandible may make it difficult to obtain an adequate seal for mask ventilation.
Hyperextension of the neck should be avoided ⇒ possibility of foramen magnum stenosis.
Endotrucheal tube⇒ size smaller than what would be expected based on age.
3) possibility difficult neuraxial anesthesia due to spinal deformity or stenosis.
4) cardiopulmonary - restrictive lung disease, central and obstructive sleep apnea, and resultant pulmonary hypertension.
5) Preoperative echocardiogram to assess for pulmonary hypertension should be considered prior to major surgery
Juvenile Idiopathic Arthritis
1) 1. Oligoarticular JIA: Involves fewer than 5 joints. Accounts for at least 50% of JIA. Often has an indolent presentation.
2. Polyarticular JIA: Involves 5 or more joints. Accounts for 25% to 40% of JIA. Usually requires DMARD therapy.
3. Psoriatic JIA: Arthritis with psoriasis.
4. Enthesitis-related JIA: Affects the spine, sacroiliac joints, and points of tendon attachment to bone.
5. Systemic-onset JIA: Presents with daily fever and rash
2) The cervical spine and temporomandibular joints may be affected in JIA
3) Common extraarticular manifestations of JIA include growth abnormalities and uveitis. Pericarditis and pleural effusions sometimes occur
Osteogenesis Imperfecta
1) bone fragility resulting in deformity and susceptibility to fracture, short stature, blue or gray sclerae, conductive hearing loss, abnormal dentin⇒ weak and discolored teeth, foramen magnum stenosis, cardiac valvular abnormalities, and bleeding diathesis.
2) Utmost care must be taken to avoid iatrogenic fracture when positioning these patients for surgery. The area under the blood pressure cuff should be padded or an arterial line placed to minimize the risk of humeral fracture. Tourniquets must be managed with similar care.
3) Succinylcholine should be avoided in patients with osteogenesis imperfecta⇒ risk of fracture upon fasciculation.
4) Airway management must be performed gently with minimal manipulation of the head and neck to avoid cervical, facial, and dental fractures.
5) Neuraxial techniques may be considered in patients with normal platelet function but may be challenging due to scoliosis. Care must be taken to avoid needle trauma to bone and intraosseous injection.
6) Preoperative: echocardiography or pulmonary function testing. Patients should be evaluated for coagulopathy preoperatively, and if necessary, treated with desmopressin (DDAVP) or platelet transfusion.
Anesthetic Considerations for Patients With Osteogenesis Imperfecta
1) Airway⇒Risk for fractures of the mandible, maxillary surface, and cervical spine
2) Bleeding⇒Platelet abnormalities
3) Cardiac⇒Congenital and valvular heart disease. Cystic degeneration of proximal aorta
4) Eyes⇒Exophthalmos-Risks associated with prone positioning
5) Hyperthermia ⇒Malignant hyperthermia, hydration, possible cooling
6) Positioning⇒ Risk for fractures
7) Pulmonary ⇒Kyphoscoliosis, restrictive lung disease
8) Regional anesthesia⇒ Fractures, intraosseous injections
Cerebral Palsy
1) antenatal or perinatal injury to the developing brain and is characterized by nonprogressive abnormalities of movement and posture such as spasticity, ataxia, and dyskinesias
2) Gastroesophageal reflux is common in cerebral palsy and may be an indication for rapid sequence intubation.
3) Bulbar dysfunction can further contribute to chronic aspiration and feeding difficulties that sometimes requires gastrostomy tube placement.
4) pulmonary morbidity: Chronic aspiration, recurrent respiratory infections, and restrictive deficits due to kyphoscoliosis.
5) Airway management may be challenging due to cervical kyphosis or dystonia, temporomandibular joint dysfunction, or poor dentition.
6) Patients with cerebral palsy have a lower minimum alveolar concentration (MAC) than normal control
7) intraoperative hypothermia due to hypothalamic dysfunction.
8) An association between cerebral palsy and latex allergy has been noted
Spina Bifida
1) diverse group of congenital malformations of the spine and spinal cord
2) Neurologic abnormalities associated with spina bifida include motor and sensory deficits below the level of the defect, Chiari II malformation, hydrocephalus, and neurogenic bladder.
3) increased incidence of latex allergy
4) neuraxial anesthesia: increased risk of inadvertent dural puncture, failed block, and neurologic injury. Ligamentum flavum may be malformed or absent, precluding identification of the epidural space with loss-of-resistance technique. The epidural space may be abnormal or nonexistent in patients who have undergone prior surgical repair. Cord tethering can result in low termination of the spinal cord and posterior placement of neural elements within the spinal canal, increasing the risk of neurologic injury with spinal anesthesia or inadvertent dural puncture.
5) MRI of the spine should be obtained to allow for examination of bony and ligamentous defects, the level of termination of the spinal cord, and the presence of masses such as lipoma or syrinx.
6)Needle placement through surgical scars should be avoided, and epidurals should be placed above the level of the spinal defect.
7) Smaller than usual epidural boluses are recommended, as abnormal anatomy might result in more extensive spread
