Perioperative management Flashcards
Contraindications to elective surgery
MI within 6 months
CVA within 2 months
Closure after laceration
Follow 6 hour golden rule to prevent infection
Nickel allergy
Nitinol contains 45% nickel
Stainless steel contains 35%
Titanium and other alloys contain <1% nickel
Thrombophlebitis
Inflammatory process that causes blood to clot and block one or more veins
Most common in lower extremities
Causes erythema, edema, pain
Risks of blood transfusion
Volume overload, hypothermia, hyperkalemia, hypocalcemia, acute transfusion reactions, hypersensitivity and anaphylaxis, and increased risk of infection
Risk of periprosthetic and surgical site infection are also increased during allogenic blood transfusion
Heparin half life
Unfractionated heparin’s half life is 1.5 hours
The following are all included in rheumatoid panel:
Rheumatoid factor (RF) Cyclic citrullinated peptide (CCP) antibody Antinuclear antibody (ANA) Erythrocyte sedimentation rate (ESR) C-reactive protein (CRP) Complete blood count (CBC)
Rheumatoid factor (RF)
Rheumatoid factor (RF) – used to help diagnose RA; it is present in significant concentrations in most people (about 80%) with RA but can also be present in people with other diseases and in a small percentage of healthy people; when positive in someone with symptoms of RA, this test can be useful to confirm the diagnosis.
Cyclic citrullinated peptide (CCP) antibody
Cyclic citrullinated peptide (CCP) antibody – may be used to help diagnose RA, especially early in the disease – potentially before symptoms even appear – and in people who are RF-negative; found in 60-70% of people with RA; when used with the RF test, CCP results can help confirm a diagnosis of RA.
Antinuclear antibody (ANA)
Antinuclear antibody (ANA) – this test is used to screen for certain autoimmune disorders, sometimes including RA, but is most often used as one of the tests to diagnose systemic lupus erythematous (SLE).
Erythrocyte sedimentation rate (ESR)
Erythrocyte sedimentation rate (ESR) – this test shows the presence of inflammation in the body and the activity of the disease. It is used to help diagnose RA and to evaluate and monitor the condition. ESR will be increased in RA but not in osteoarthritis.
C-reactive protein (CRP)
C-reactive protein (CRP) – this test also indicates inflammation and tests for the activity of the disease. It may be used to help diagnose RA and to evaluate and monitor the condition. An increased level of CRP occurs in RA but not in osteoarthritis.
Complete blood count (CBC)
Complete blood count (CBC) – this is a group of tests used to help evaluate the person’s red and white blood cells and hemoglobin to help monitor for anemia and/or a decrease in white blood cells.
Fluid resuscitation following LE trauma
Significant amount of blood is lost with compound ankle injuries. Patients are at increased risk of developing hypovolemic shock. In cases of inadequate resuscitation, patients are mostly likely to develop the lethal triad of hypothermia, coagulopathy, and acidosis. In order to avoid this lethal triad and hypovolemic shock, patients with long bone fractures are adequately resuscitated with intravenous fluids.
Crystalloid is the first choice of fluid in resuscitation. Intravenous fluids should be judiciously used with the aim of providing routine maintenance fluids to meet insensible losses, to maintain normal status of body fluid compartments and enable renal excretion of waste products.
Fat embolism
Fat emboli may occur in patients with long bone fractures. However, some patients develop a triad of petechiae in skin, respiratory depression and altered state of consciousness. This is known as fat embolism syndrome. Traditionally, it develops 24-72 hours following trauma. Diagnosis is mainly clinical and is supported by imaging. Fat embolism syndrome can be detected early by continuous pulse oximetry in high-risk patients. It has been proposed that when fractures of long bones occur, fat droplets are released into the venous system which are then embedded in the pulmonary capillary bed. From there, they travel to the brain via AV shunts. This results in local ischemia and inflammation, with concomitant release of inflammatory mediators and vasoactive amines and platelet aggregation
Concentric Contractions
Muscle actively shortening When a muscle is activated
Raising of a weight during a bicep curl
Eccentric Contractions
Muscle actively lengthening during normal activity, muscles are often active while they are lengthening
Setting an object down gently (the arm flexors must be active to control the fall of the object)
Isometric Contraction
Muscle actively held at a fixed length a third type of muscle contraction, isometric contraction, is one in which the muscle is activated, but instead of being allowed to lengthen or shorten, it is held at a constant length
Carrying an object in front of you
Herbal medicines that reduce platelet aggregation
Used to treat cardiovascular disease
Andrographis, feverfew, garlic, ginger, Ginkgo, ginseng, hawthorn, horse chestnut, and turmeric
Herbal medicines that interact with Warfarin
Cranberry, danshen, dong quai, Ginkgo, ginseng, green tea, and St John’s wort were found to have potential interactions with warfarin
Why order pre-op CBC
preoperative laboratory tests are carried out for assessing the perioperative risks associated with surgery and their timely management to reduces the morbidity and mortality associated with them. Preoperative CBC is one of the most important tests in the basic investigation panel. Preoperative anemia (hemoglobin- Hb) can be evaluated on CBC. Proceeding surgically in an anemic patient will lead to a higher likelihood of postoperative transfusion need. There is a higher risk of intraoperative bleeding (Low platelets) and poor wound healing due to decreased oxygen supply in those found to be anemic or with thrombocytopenia. During a CBC: Hb, Rbcs, platelets and Hct provide important information regarding the anemia and its etiology. Timely diagnosis of anemia helps in preoperative treatment by oral supplementation. In turn, this reduces the need for postoperative transfusion and aids in healthy wound healing; yielding shorter hospital stays.
Osteoid osteoma
Remember that osteoid osteomas are relieved by aspirin (and other PROSTAGLANDIN inhibitors). They are highly vascular tumors - so substances that cause vasodilation, like alcohol, - may cause an acute pain crisis: The underlying cause of osteoid osteomas is unknown. The nidus has been found to contain profuse nerve fibers adjacent to areas abundant in arterioles. Prostaglandin synthesis has been shown to occur within the nidus. It’s suggested that these prostaglandins play an important role as mediators of both pain and vasodilation which stimulate the nerve endings by increasing the blood flow within the tumor.
Preop insulin
Give long acting insulin at ½ the normal dose, and hold short acting insulin the morning of surgery.
BMA
Bone marrow is often aspirated to utilize the stem cells for tissue repair applications such as bone regeneration. The specific type of stem cells of interest are adult mesenchymal stem cells (MSCs), which differentiate into osteoprogenitor cells. These further differentiate into mature bone-forming cells, called osteoblastsOf the choices listed, only autologous tibia bone marrow aspirate is capable as a source of osteogenic mesenchymal precursor cells.
Toxic dose
Toxic dose for Lidocaine plain = 4.5mg/kg
Toxic dose for Lidocaine with epinephrine = 7mg/kg.
Toxic dose for Marcaine plain = 3mg/kg.
Toxic dose of lidocaine plain for a 60kg female
60kg x 4.5mg = 270mg. 270mg % (10mg/mL) = 27mL.
ASA
ASA 1: A normal healthy patient. Example: Fit, non-obese (BMI under 30), a nonsmoking patient with good exercise tolerance.
ASA 2: A patient with a mild systemic disease. Example: Patient with no functional limitations and a well-controlled disease (e.g., treated hypertension, obesity with BMI under 35, frequent social drinker or is a cigarette smoker).
ASA 3: A patient with a severe systemic disease that is not life-threatening. Example: Patient with some functional limitation as a result of disease (e.g., poorly treated hypertension or diabetes, morbid obesity, chronic renal failure, a bronchospastic disease with intermittent exacerbation, stable angina, implanted pacemaker).
ASA 4: A patient with a severe systemic disease that is a constant threat to life. Example: Patient with functional limitation from severe, life-threatening disease (e.g., unstable angina, poorly controlled COPD, symptomatic CHF, recent (less than three months ago) myocardial infarction or stroke.
ASA 5: A moribund patient who is not expected to survive without the operation. The patient is not expected to survive beyond the next 24 hours without surgery. Examples: ruptured abdominal aortic aneurysm, massive trauma, and extensive intracranial hemorrhage with mass effect.
ASA 6: A brain-dead patient whose organs are being removed with the intention of transplanting them into another patient.
INR, PT, PTT
A normal INR = ~1
An INR range of 2.0 to 3.0 is generally an effective therapeutic range for people taking warfarin and would be at increased risk of bleeding
A normal PTT time = 25 to 35 seconds
A normal PT time = 11 to 13.5 seconds
Prothrombin time test results can be presented in two ways; in seconds and INR. In seconds, the average time range for blood to clot is about 10 to 14 seconds. A number higher than that range means it takes blood longer than usual to clot. A number lower than that range means blood clots more quickly than normal.
