Glossary for Chapter 13
I compiled this glossary with the help of Jeriddian, a doctor of Internal Medicine and the administrator/founder of the Global Justice Alliance webpage and forum. Previously, Dr. Jeriddian helped me edit and improve Chapter 13, which began as a load of medical clichés and wound up as a realistic ER drama.
In order of appearance:
IED: Improvised Explosive Device
Lap: short for "Laparotomy," a surgical procedure involving an incision through the abdominal wall to gain access into the abdominal cavity.
Blood pressure (BP): 120 over 80 is ideal. Anything below 90/60 or above 160/100 is cause for concern; coma and death can occur below 50/30. The first number is always higher and indicates systolic pressure – the heart is contracting and driving blood through the arteries. The second indicates diastolic pressure – the heart is relaxing and filling with blood for the next contraction.
Heart rate: Normal heart rate is usually between 60 and 100 beats for minute for above 100 bpm indicates sinus tachycardia (sinus tach), or an abnormally fast heart rate.
Intubation: placement of a flexible plastic tube into the throat to protect the patient's airway (trachea) and provide a means of mechanical ventilation. The endotracheal tube (ET tube) has an inflatable balloon around the lower part which inflates after the tube is placed in the trachea, creating an airtight seal to allow the ventilator to force air into the lungs as needed.
Pneumo: short for pneumothorax, or a collapsed lung. The lung is punctured or otherwise looses pressure from leaking air. Patients can die unless the leak is fixed and pressure from air leaked into the chest cavity is removed, allowing the lung to expand normally. This often requires a chest tube, inserted through the chest wall to remove leaked air and help re-expand the lung.
Ambu bag: a hand-held device used to provide mechanical breathing. It is fitted to a mask which covers the patient's nose and mouth and creates an air tight seal against the face. A hollow squeeze-ball forces air through the mask into the patient's lungs, then allows the patient to "exhale" as the ball is released and fills up with air. An oxygen line is usually connected to the ambou bag to supply extra oxygen to the patient.
Epigastrium: the upper central region of the abdomen; forms a triangle beneath the chest, and is located slightly below the xiphoid process (bottom of the sternum).
Betadine: a topical antiseptic used to prep the skin of surgical patients about to undergo surgery. Patients allergic to betadine are prepped with alcohol.
Morphine: a powerful pain killing opiate derived from the poppy plant. Doses used can vary from patient to patient in regards to individual pain tolerance and the source of the pain. 10 mg (milligrams) is a fairly large dose in most cases.
Midazolam: a powerful sedative/muscle relaxant. While in the same class as Valium and ativan, the drug's primary use is in conscious sedation and preparation for general endotracheal anesthesia. Its main effect is forgetfulness; patients given this drug do not remember anything afterward while under its effect.
Succinylcholine: widely used drug to induce muscle relaxation during general anesthesia, initially to make intubation possible by eliminating the gag reflex. In addition, it is usually required during surgery to stop involuntary muscle spasms resulting from incisions and manipulation of the tissues.
Ophthalmologist: eye specialist and/or eye surgeon
O negative blood: "universal" blood, without any antigens, that can be given to any blood type. Any time a blood transfusion is ordered, the blood must usually be "typed and crossed" to match the donor blood type to the recipient to prevent very severe reactions that can be fatal. In emergencies, where one does not have time for that, "universal" O-negative donor blood is used, as it is not required to be put through this process.
Blood is usually given as "units," each about 150 to 200 cc (about 7 fluid ounces) which, when rehydrated with saline, approximate 500 cc (about a pint) of whole blood.
Ringers: short for "Lactated Ringer's solution," Ringers is a solution that is isotonic with (or has the same concentration of solutes as) blood and is intended for intravenous administration. Lactated Ringer's solution is abbreviated as "LR" or "RL."
Subclavian: the subclavian artery and vein are located underneath the clavicles (collarbones) to either side of the upper chest. The subclavian arteries come out of the aortic arch and connect to the brachial arteries on both sides. The subclavian veins connect at the junction of the cephalic and basilic veins (which drain the arms), and also connect to other veins in the chest, which then connect to the superior vena cava. The subclavian vein is a frequent site for the insertion of a "central venous line," an IV line for drugs and other fluids that should not be given through veins in the limbs.
Short gut syndrome: a condition where there is not enough small intestine to properly absorb nutrients form the digestive tract and supply nutrition for the body. Of all the parts of the gastrointestinal (GI) tract, the small intestine is the one part without which people cannot live. Causes for the loss of small intestine are varied, but the most common are trauma, bowel infarction (tissue that dies from loss of blood supply), and Crohn's disease. These conditions usually required surgical removal of the dead portions of the intestine. People usually have 20 feet of small intestine, and they experience short gut syndrome when they are left with approximately 2 to 3 feet or less. Chronic digestion problems and constant diarrhea ensue, complicated by dehydration, electrolyte disorders, and malnutrition. Patients can be treated with IV nutrient solutions, but life expectancy is short.
Aorta (abdominal): largest artery in the abdominal cavity. It runs down the back of the abdomen, just in front of the spine, and behind the stomach, kidneys, and small intestine to the iliac and femoral arteries. Puncture = bad.
Celiac artery: first major branch of the abdominal aorta; feeds the liver, stomach, and spleen.
Exsanguinate: to bleed to death
Lidocaine: a common local anesthetic; usually injected by syringe to numb an area in preparation for a minor surgical procedure. Also used for cardiac arrhythmias, usually in code situations only, as it can cause as much cardiac arrhythmia as it can cure. It is therefore not a first-line drug for this use and has now been restricted to use as a second or third line anti-arrhythmic agent in Code Blue situations; if this drug is required, you've got a problem.
Anesthesiologist: sometimes nicknamed a "gas passer", this doctor is specifically trained to administer anesthesia and manage the medical care of patients before, during, and after surgery.
Lumen: a cavity, channel, or partition within a tube. A three-lumen catheter would have a sealed, Y-shaped divider in it so three different liquids could run down the same tube into the same vein.
Catheter: a tube that can be inserted into a body cavity or vessel; has a port on one end so other tubes can be connected to it.
"Intubated at 100 percent" – Kim's breathing tube is giving her 100 percent oxygen
CBC: Complete Blood Count; it literally counts the concentration of blood cells in a sample. It is broad screening test to check for anemia (low blood cell count), infections, and many other diseases.
CMP: Comprehensive Metabolic Panel. A standard suite of 14 to 20 blood tests which serves as an initial broad screening tool; provides an important baseline of a patient's basic physiology. Used as an important check of kidney function, liver function, electrolytes, protein levels, and indirectly as a check on fluid balance.
PT: Prothrombin Time. Measures how well the blood can clot and it is also used to help detect and diagnose a bleeding disorder. It is also often used to see how well a major blood-thinning medication (warfarin) is working to prevent blood clots.
PTT: Partial Thromboplastin Time. This is a second test measuring the blood's ability to clot, using a different biochemical pathway than the PT test. Detects abnormalities in blood clotting due to specific diseases, and is used to monitor the effects of heparin, another anti-clotting drug.
Blood cultures times two: When infection is suspected in the blood (sepsis), the infectious agent is identified by drawing blood and trying to grow the agent in the microbiology lab. The general rule is to draw two blood culture samples from two different sites on the body, thus the saying "blood cultures times two."
The reason for this is that one blood culture has a 65% chance of succeeding in growing the bug. Two independent cultures have a 90% chance, thus it is the standard. Three cultures have a 95% chance, but are usually not worth the time, except in some very special circumstances.
D-dimer: the most sensitive test available to measure the breakdown products of the "clotting cascade." It is mainly used to detect DIC, or Disseminated Intravascular Coagulation, a disorder that is usually lethal if left untreated. What happens is that the body's coagulation system is aberrantly triggered inside the vascular system to start clotting abruptly. At the same time the blood starts to clot, a counteracting mechanism is activated to "chew up" and dissolve the clot formed inside the blood vessels. This process scatters clot fragments, which can cause obstructions of blood flow, infarctions, heart attacks, strokes, and ironically, uncontrollable bleeding since the coagulation system is exhausted unnaturally. There are four major causes of DIC: massive tissue injury (such as wartime injury in the story), cancer, obstetrical disasters, and sepsis (widespread infection through the blood usually from gram negative bacteria, but any bug can do it).
Fibrinogen: a test to evaluate a body's ability to form a blood clot by measuring the level of fibrinogen, one of the major substrates of the coagulation system. It is often used in detecting coagulation abnormalities such as DIC (see above).
Ventilator settings -
Vital capacity: the capacity of the lungs in a normal breath. 600 cc is about 2/3 of a quart.
Rate 20: breathing rate is 20 breaths/minute
FiO2: the fractional increment of oxygen in the air being pushed into the lungs. A FiO2 of 1.0 equals 100% oxygen, and a FiO2 of 0.5 equals 50% oxygen. Normal oxygen concentration in the air is 21% (F-I-O2 .21).
PEEP: Positive End Expiratory Pressure. PEEP is used when the ventilator maintains a constant low level of increased air pressure in the lungs at all times. The machine pushes air into the lungs at the start of each breath, relieving much of the work the patient is unable to do and requiring much less exertion from the diaphragm to draw air inside.
PEEP itself is measured as the amount of pressure above normal required to elevate a 1 centimeter-diameter column of water up a number of centimeters. A PEEP of 5 means the pressure applied to the lungs is equal to the pressure required to push a 1-centimeter-diameter column of water upward 5 centimeters.
Usually, PEEP values range anywhere from 2.5 to 25. PEEPs above 25 have a high rate of causing a pneumothorax and can greatly interfere with breathing and blood return to the heart.
ABG: Arterial Blood Gas test. Used to measure the success and efficiency of the lungs to deliver oxygen to the blood and get rid of carbon dioxide.
pH 7.28: pH is a measure of the degree of acidity in the blood. In order for the life processes of the body to even work at all, and thus allow the organism to live, the pH must be maintained within a very narrow range. (The number itself is a logarithmic measure of the concentration of hydrogen atoms within a solution, in this case arterial blood.) Human serum must be maintained at a pH of 7.4. While 7.35 to 7.45 is defined as the normal range, a severe problems develop if the pH is less than 7.15 or greater than 7.55.
pO2 325: pO2 is a measure of the "partial pressure of oxygen" that is dissolved into the serum and not deposited onto blood cells. There is a very close association between this partial pressure of oxygen in the serum and the actual saturation of blood cells with oxygen. Normal saturation is better than 90% in arterial blood, which occurs at a pO2 of 60 mm Hg (millimeters of mercury, which is essentially the same as centimeters of H20), usually shortened to pO2 60.
In this case, a pO2 of 325 indicates that a high concentration of oxygen (100%) is being artificially administered to the patient and the red blood cells can't absorb it all.
pCO2 28: Similar to pO2, pCO2 measures the partial pressure of carbon dioxide dissolved into the blood serum. A normal pCO2 is about 40.
If the lungs are working harder than normal to get rid of CO2 (such as in hypoxia, severe pain, hyperventilation, etc.), then the lungs will deplete the CO2 content in the blood faster than the body is creating it from its own metabolism, driving the pCO2 number downward. The number also goes down if the patient if breathing pure oxygen.
A higher number means the lungs are having problems getting rid of the CO2 the body is producing, as is the case with a gas exchange problem in the lungs (pneumonia, emphysema, pulmonary embolus, pulmonary edema, etc.).
Bicarb 26: "Bicarb" is a calculated value, not actually measured. It is a calculation of HCO3 (bicarbonate ions) in the blood and corresponds to the same number as the bicarbonate (which is measured) on the CMP (see Labs, above). Normal levels are between 18 and 23; the high number in the story reflects the effects of stress and high oxygen levels, among other factors.
Dopamine: a chemical related to the stress hormones norepinephrine and epinephrine (adrenalin). It given only intravenously through a central venous line. Its purpose is to increase heart rate and blood pressure in a person whose blood pressure is absent or dangerously low, as in the case of severe hemorrhage, cardiac shock, septic shock, etc.
Neosynephrine: similar in purpose to dopamine, this drug acts on the vascular tree and makes blood vessels constrict, increasing blood pressure. It is also only given through a central venous line.
20 mikes: shorthand for 20 micrograms; equal to 0.02 milligrams. (Very tiny.)
Sevoflurane: a sweet-smelling, non-flammable, highly fluorinated methyl isopropyl ether used for the induction and maintenance of general anesthesia. It is often administered by inhalation in a mixture of nitrous oxide and oxygen.
Transverse colon – the longest and most movable part of the colon (large intestine); passes across the abdomen, just below the liver and stomach.
There are three sections of the colon. The first is the ascending colon, which joins with the small intestine and rises straight up on the right side of the body. It then turns sideways to become the transverse colon, which travels across the abdomen towards the left. Turning downward, it becomes, in an amazing burst of naming logic, the descending colon, which leads into the rectum and out.
3-0 gut: a "three ought" or 0-0-0 diameter suture thread. In the old days, intestinal material from cows and sheep was shaped into string and used as sutures because they were able to hold their ties for a long enough period to allow the sewn body parts to heal properly, yet because the sutures were made of biologic material, the body would eventually reabsorb them so they wouldn't be permanent.
Today, the threads are made synthetically, but the name "gut" stuck. The thickness of the suture string ranges from 5 -0 (0-0-0-0-0), which is the thinnest, to 1-0 (0), to 1, 2, or even 3 gut, which is thick and hard to work with. The most common diameters used, though, are 3-0 and 2-0.
V-Fib – Ventricular fibrillation. A life-threatening condition in which the electrical pulses driving the heart are disrupted, causing uncoordinated contraction of cardiac muscle in the heart, making them tremble and quiver rather than contract properly. No blood is pumped to the body. Electrical shocks are required to jolt the heart back into its normal rhythm.
Asystole: Called a "flatline" in common jargon, asystole is a state where there is no heart activity at all; there is no detectable electrical activity and no contractions. Defibrillation is useless in most cases and CPR must be used, sometimes followed by another cycle of defibrillation and other chemicals, even though the outlook is usually grim. Unless the condition can be reversed immediately, asystole is usually used to pronounce death.
If there are other terms you think I should include, either from this chapter or from others, feel free to send me a PM.