The clinical problem-oriented approach to reading is different from the classic “systematic” research of a disease. A patient’s presentation rarely provides a clear diagnosis; hence, the student must become skilled in applying textbook information to the clinical setting. Furthermore, one retains more information when one reads with a purpose. In other words, the student should read with the goal of answering specific questions. There are several fundamental questions that facilitate clinical thinking:
1. What is the most likely diagnosis?
2. How can you confirm the diagnosis?
3. What should be your next step?
4. What is the most likely mechanism for this disease process?
5. What are the risk factors for this disease process?
6. What are the complications associated with this disease process?
7. What is the best therapy?
Reading with the purpose of answering the seven fundamental clinical questions improves retention of information and facilitates the application of book knowledge to clinical knowledge.
WHAT IS THE MOST LIKELY DIAGNOSIS?
The method of establishing the diagnosis has been covered in the previous section. One way of attacking this problem is to develop standard approaches to common clinical problems. It is helpful to understand the most common causes of various presentations, such as “The most common cause of serosanguineous nipple discharge is an intraductal papilloma.”
The clinical scenario might be “A 38-year-old woman is noted to have a 2-month history of spontaneous blood-tinged right nipple discharge. What is the most likely diagnosis?”
With no other information to go on, the student notes that this woman has a unilateral blood-tinged nipple discharge. Using the “most common cause” information, the student makes an educated guess that the patient has an intraductal papilloma. If instead the patient is found to have a discharge from more than one duct and a right-sided breast mass is palpated, it is noted: “The bloody discharge is expressed from multiple ducts. A 1.5-cm mass is palpated in the lower outer quadrant of the right breast.”
Then the student uses the clinical pearl: “The most common cause of serosanguineous breast discharge in the presence of a breast mass is breast cancer.”
The most common cause of serosanguineous unilateral breast discharge is intraductal papilloma, but the main concern is breast cancer. Thus, the first step in evaluating the patient’s condition is careful palpation to determine the number of ducts involved, an examination to detect breast masses, and mammography. If more than one duct is involved or a breast mass is palpated, the most likely cause is breast cancer.
HOW CAN YOU CONFIRM THE DIAGNOSIS?
In the preceding scenario, it is suspected that the woman with the bloody nipple discharge has an intraductal papilloma, or possibly cancer. Ductal surgical exploration with biopsy would be a confirmatory procedure. Similarly, an individual may present with acute dyspnea following a radical prostatectomy for prostate cancer. The suspected process is pulmonary embolism, and a confirmatory test would be a ventilation/perfusion scan or possibly a spiral CT examination. The student should strive to know the limitations of various diagnostic tests, especially when they are used early in a diagnostic process.
WHAT SHOULD BE YOUR NEXT STEP?
This question is difficult because the next step has many possibilities; the answer may be to obtain more diagnostic information, stage the illness, or introduce therapy. It is often a more challenging question than “What is the most likely diagnosis?” because there may be insufficient information to make a diagnosis and the next step may be to obtain more data. Another possibility is that there is enough information for a probable diagnosis and that the next step is staging the disease. Finally, the most appropriate answer may be to begin treatment. Hence, based on the clinical data, a judgment needs to be rendered regarding how far along one is in the following sequence.
1. Make a diagnosis 2. Stage the disease
3. Treat based on stage 4. Follow the response
Frequently, students are taught to “regurgitate” information that they have read about a particular disease but are not skilled at identifying the next step. This talent is learned optimally at the bedside in a supportive environment with the freedom to take educated guesses and receive constructive feedback. A sample scenario might describe a student’s thought process as follows:
1. Make a diagnosis: “Based on the information I have, I believe that Mr Smith has a small bowel obstruction from adhesive disease because he presents with nausea, vomiting, and abdominal distension and has dilated loops of bowel on radiography.”
2. Stage the disease: “I do not believe that this is severe disease because he does not have fever, evidence of sepsis, intractable pain, leukocytosis, or peritoneal signs.”
3. Treat based on stage: “Therefore, my next step is to treat with nothing per mouth, nasogastric tube drainage, and observation.”
4. Follow the response: “I want to follow the treatment by assessing his pain (asking him to rate the pain on a scale of 1 to 10 every day), recording his temperature, performing an abdominal examination, obtaining a serum bicarbonate level (to detect metabolic acidemia) and a leukocyte count, and reassessing his condition in 24 hours.”
In a similar patient, when the clinical presentation is unclear, perhaps the best next step is a diagnostic one such as performing an oral contrast radiologic study to assess for bowel obstruction.
The vague question “What is your next step?” is often the most difficult one because the answer may be diagnostic, staging, or therapeutic.
WHAT IS THE LIKELY MECHANISM FOR THIS DISEASE PROCESS?
This question goes further than making the diagnosis and requires the student to understand the underlying mechanism of the process. For example, a clinical scenario may describe a 68-year-old man who notes urinary hesitancy and retention and has a large, hard, nontender mass in his left supraclavicular region. This patient has bladder neck obstruction due to benign prostatic hypertrophy or prostatic cancer. However, the indurated mass in the left neck area is suggestive of cancer. The mechanism is metastasis in the area of the thoracic duct, which drains lymph fluid into the left subclavian vein. The student is advised to learn the mechanisms of each disease process and not merely to memorize a constellation of symptoms. Furthermore, in general surgery it is crucial for students to understand the anatomy, function, and how a surgical procedure will correct the problem.
WHAT ARE THE RISK FACTORS FOR THIS DISEASE PROCESS?
Understanding the risk factors helps the practitioner establish a diagnosis and determine how to interpret test results. For example, understanding the risk factor analysis may help in the treatment of a 55-year-old woman with anemia. If the patient has risk factors for endometrial cancer (such as diabetes, hypertension, anovulation) and complains of postmenopausal bleeding, she likely has endometrial carcinoma and should undergo endometrial biopsy. Otherwise, occult colonic bleeding is a common etiology. If she takes nonsteroidal anti-inflammatory drugs or aspirin, peptic ulcer disease is the most likely cause.
A knowledge of the risk factors can be a useful guide in testing and in developing the differential diagnosis.
WHAT ARE THE COMPLICATIONS OF THIS DISEASE PROCESS?
Clinicians must be cognizant of the complications of a disease so that they can understand how to follow and monitor the patient. Sometimes, the student has to make a diagnosis from clinical clues and then apply his or her knowledge of the consequences of the pathologic process. For example, a 26-year-old man complains of a 7-year history of intermittent diarrhea, lower abdominal pain, bloody stools, and tenesmus and is first diagnosed with probable ulcerative colitis. The long-term complications of this process include colon cancer. Understanding the types of consequences also helps the clinician to become aware of the dangers to the patient. Surveillance with colonoscopy is important in attempting to identify a colon malignancy.
WHAT IS THE BEST THERAPY?
To answer this question, the clinician not only needs to reach the correct diagnosis and assess the severity of the condition but also must weigh the situation to determine the appropriate intervention. For the student, knowing exact dosages is not as important as understanding the best medication, route of delivery, mechanism of action, and possible complications. It is important for the student to be able to verbalize the diagnosis and the rationale for the therapy.
Therapy should be logical based on the severity of the disease and the specific diagnosis. An exception to this rule is in an emergent situation such as shock, when the blood pressure must be treated even as the etiology is being investigated.
1. There is no replacement for a meticulous history and physical examination.
2. There are four steps in the clinical approach to the patient: Making the diagnosis, assessing the severity of the disease, treating based on severity, and following the patient’s response.
3. There are seven questions that help bridge the gap between the textbook and the clinical arena.
Doherty GM. Preoperative care. In: Doherty GM, ed. Current Surgical Diagnosis and Treatment. 13th ed. New York, NY: McGraw-Hill Publishers; 2010:12-23.
Englebert JE. Approach to the surgical patient. In: Doherty GM, ed. Current Surgical Diagnosis and Treatment. 13th ed. New York, NY: McGraw-Hill Publishers; 2010:1-5.