Preoperative Laboratory and Diagnostic Studies

Preoperative Laboratory and Diagnostic Studies

Preoperative Labratorey and Diagnostic Studies The concept of standardized testing in all presurgical patients regardless of age or medical condition is no longer considered medically appropriate. Unnecessary testing is inefficient and expensive, and it requires additional technical resources. Inappropriate studies may lead to costly evaluation of borderline or false-positive laboratory and diagnostic test abnormalities

This may result in unnecessary operating room delays, cancellations, and potential patient risk through additional testing and follow up.

It has been well documented in academic studies that routine preoperative screening tests in an asymptomatic healthy patient have no beneficial effect on surgical or anesthesia outcomes.

Patients require preoperative diagnostic and laboratory evaluation that is consistent with their medical history, the proposed surgical procedures, and the potential for intraoperative blood loss. Preoperative diagnostic and laboratory testing should be obtained for specific clinical indications that may increase perioperative risk and not simply because the patient is to undergo a surgical procedure

Complete Blood Count, Hemoglobin, and Hematocrit The proposed surgical procedure and potential blood loss, together with individualized clinical indications, should determine the requirement for a blood count preoperatively

Clinical indications History of increased bleeding Hematologic disorders Renal disease Chemotherapy or radiation Treatment Steroid or anticoagulant therapy poor nutrition/malabsorption status surgical procedures with anticipatehighblood loss Truma IHD

Liver Function Testing There is no routine preoperative anesthesia requirement for liver function testing. It should be based on a history of hepatic injury and physical examination findings..

Clinical indications History of viral, alcohol, or drug-induced hepatitis Jaundice, cirrhosis, portal hypertension, biliary or gallbladder disease Hepatotoxic drug exposure Infiltration of tumor Bleeding disorders

Renal Function Testing Diabete Hypertension Cardiac disease Dehydration; nausea and vomiting; anorexia; bulimia Increase fluid overload, such as in congestive heart failure, peripheral edema, or ascites Renal, hepatic, or cardiac impairment Hematuria; nocturia; polyuria; Oliguria; anuria History of renal transplantation

Coagulation Testing Clotting studies are not indicated as a routine preoperative evaluation A careful history that includes drug therapies and physical examination will provide guidance if coagulation testing is indicated.

Clinical indications History of a bleeding disorder or previous excessive intraoperative surgical bleeding hepatic disease Poor nutritional status Use of anticoagulants or other drugs that affect coagulation.

Urinalysis There is no indication during preoperative anesthesia evaluation for routine urinalysis. Primary clinical indications could include a suspected urinary tract infection or unexplained fever or chills.

Pregnancy Test Pregnancy testing can be based on the history and specific questions. Clinical indications can include the date of the last menstrual period, sexual activity, type or absence of birth control method, and patient or physician intuition.

The Electrocardiogram The ECG is used to determine a previous history of MI, conduction/rhythm disturbances, ischemia, chamber hypertrophy, and metabolic/electrolyte disorders).

Clinical indications History of CAD or MI, hypertension, diabetes, congestive heart failure, chest pain, palpitations Abnormal valvular murmurs Peripheral edema Syncope and Dizziness Dyspnea on exertion, shortness of breath, paroxysmal nocturnal dyspnea Cerebrovascular disease

The Chest Radiograph The chest radiograph should be used to assess concerned abnormalities that are present by history or physical examination

Clinical indications Auscultation of rales or rhonchi Advanced COPD and blebs Pulmonary edema Suspected pneumonia Pulmonary or mediastinal masses Tracheal deviation Aortic aneurysm Atelectasis Cardiomegaly, pulmonary hypertension, or dextrocardia

Preoperative Pulmonary Function Assessment PFTs are not considered routine for patients with a history of asthma, emphysema, or COPD. Clinical examination and a careful history will indicate the patient's current respiratory status and the potential for anesthesia/surgical pulmonary compromise. Preoperative PFTs can assess potential respiratory complications in patients undergoing surgical resection of the lung. PFTs determine the patient's pulmonary reserve and whether the patient may require postoperative chronic ventilation support.

Patients with ischemic heart disease require a complete blood count (CBC), and transfusion for anemia should be considered. In nonoperative settings but in populations with critical illness or chronic disease states associated with known CAD or risk factors for CAD, hemoglobin levels higher than 13.5 g/dl are associated with adverse outcomes. [30] A recent study suggests that even mild preoperative anemia increases postoperative mortality and cardiac morbidity in men but not in women. [31] Individuals with preoperative hematocrits between 39% and 51% had the lowest risk of adverse outcomes in this Veteran's Administration surgical population