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86 Cards in this Set

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Which maternal hemodynamic parameter has the greatest decrease during normal gestation?
• During normal gestation, the greatest decrease in a hemodynamic parameters occurs in the systemic vascular resistance (-20% SVR).
Which maternal hemodynamic parameter shows the greatest increase during normal gestation?
• During normal gestation, the greatest increase in a hemodynamic parameter occurs in the cardiac output (+50% CO).
Identify 3 maternal physiological disturbances that pose the greatest risk to the fetus.
• The greatest risk to the fetus occurs following maternal catastrophes involving
› (1) severe hypoxia,
› (2) hypotension, and
› (3) acidosis.
What is the most serious fetal risk associated with maternal surgery during pregnancy?
• The most serious fetal risk associated with maternal surgery during pregnancy is that of uterine asphyxia.
How does minute ventilation change during pregnancy?
• Minute ventilation increases by up to 45% during pregnancy.
What respiratory parameter changes most to increase minute ventilation during pregnancy? What physiological factors - prompt the increase in minute ventilation during pregnancy?
• During pregnancy, resting minute ventilation increases (up to 45%) owing primarily to an increase in tidal volume, with minimal, if any, change in inspiratory rate and pattern.
• The rise in minute ventilation results from hormonal changes (increased progesterone) and increased C02 production.
• Progesterone acts as a direct respiratory stimulant and the progesterone-induced increase in chemoreceptor sensitivity results in a steeper and leftward shifted C02 ventilatory response curve.
State the loading and maintenance doses of magnesium sulfate administered for seizure prophylaxis in pregnancy-induced hypertension (PIH).
• For seizure prophylaxis in pregnancy-induced hypertension (preeclampsia) magnesium sulfate is administered at a loading dose of 4-6 g over 20-30 minutes, followed by a maintenance dose of 1-2 g/hr., continued for up to 24 hours postpartum.
What is the earliest sign of magnesium toxicity?
• Clinically, the therapeutic effects of magnesium therapy are estimated by the response to deep tendon reflexes. Marked depression of deep tendon reflexes is an indication of impending magnesium toxicity. At therapeutic magnesium levels (4-6 mEq/L), lethargy, nausea &vomiting, and facial flushing may occur. At magnesium levels greater than 6 mEq/L, loss of deep tendon reflexes and hypotension ensue.
What specific changes are often seen in the ECG when magnesium levels reach 10 mEq/L?
• At magnesium levels of 10 mEq/L, prolonged P-Q intervals and widened QRS complexes may be observed. Asystole occurs at 20 mEq/L.
Identify the drugs that are compatible with the mother who is breast-feeding her infant.
• Most drugs are safe during lactation. Typically only 1% to 2% of the maternal dose appears in breast milk. Lithium and ergotamine are best avoided during lactation.
The parturient has received a neuraxial opioid and is experiencing nausea and vomiting. Which drug is effective for opioid induced nausea in laboring women, but has the most significant side-effects?
• Droperidol is effective for the treatment of nausea in laboring women, but it has significant side-effects, namely dysphoria, akathisia (an unpleasant sensation of "inner restlessness" accompanied by the inability to sit still), and oculogyric crisis.
• Furthermore, the FDA has issued a "black box" warning because of the concern that the administration of droperidol may result in an increased risk of cardiac arrhythmias.
Describe early (Type I) decelerations of fetal heart rate. Are early decelerations a sign of fetal distress?
• Early decelerations are characterized by the slowing of the fetal heart rate that begins with the onset of uterine contractions.
• Decreases in heart rate are usually not more than 20 bpm or below an absolute rate of 100 bpm.
• This deceleration pattern is thought to be caused by vagal stimulation secondary to compression of the fetal head. Early decelerations are NOT associated with fetal distress.
Identify the most common cause of anesthesia- related maternal mortality on the obese parturient.
• The most common anesthesia-related cause of maternal mortality in the obese parturient is airway complications.
Identify 5 signs and symptoms of venous air embolism in the pregnant patient.
• Signs and symptoms of venous air embolism in the pregnant patient are
› (1) mill-wheel murmur detected over the pericardium,
› (2) chest pain,
› (3) dyspnea,
› (4) decreased end-tidal C02, and
› (5) elevated central venous pressure.
› Late signs of venous air embolism are hypotension, tachycardia, and cardiac dysrhythmias.
The obstetric patient develops a venous air embolism-in what position will you place the parturient?
• The parturient who develops a venous air embolism (incidence as high as 95%) should be placed in a slight anti-trendelenburg position with left lateral tilt of 15.
• This position increases the likelihood of trapping air in the right atrium, from which it can be aspirated via a central venous catheter.
Your patient has mitral stenosis and is being prepared for an emergent cesarean section. The patient has not been adequately hydrated and hypotension is a concern- which anesthetic technique will you use?
• A general anesthetic would be the technique of choice for emergent cesarian section when hypotension is a major concern.
• Although regional and neuraxial techniques are viable options, hypotension is more common with these techniques, compared to general anesthesia.
• Hypotension is most common with a spinal anesthetic, less common with epidural anesthetics, and modestly less common with a regional technique; a general anesthetic is associated with the least likelihood of hypotension.
• Hypotension: spinal > epidural > general anesthesia
A parturient has gestational diabetes mellitus and is hyperglycemic on admission for labor and delivery. Will her infant be normoglycemic, hypoglycemic, or hyperglycemic? Why?
• Neonatal hypoglycemia occurs in 5% to 12% of cases of pregestational and gestational diabetes mellitus (DM).
• The neonatal hypoglycemia is presumed to result from sustained fetal hyperinsulinemia that develops in response to chronic intrauterine hyperglycemia. Decreased fetal oxygen secondary to uncontrolled maternal DM may also promote hypoglycemia in the fetus and newborn.
Elderly patients have changes in autonomic function referred to as physiologic beta blockade. Identify two cellular changes that explain the blunted B-receptor response in the geriatric patient. What two cardiovascular responses are altered due to the blunted B-receptor response?
• Decreased B-receptor responsiveness is secondary to both decreased receptor affinity and alterations in signal transduction (specifically, decreased intracellular cyclic AMP).
• Decreased B-receptor responsiveness assumes functional importance when increased flow demands are placed on the heart.
• Normally, B-receptor-mediated mechanisms act to increase the heart rate, venous return, and systolic arterial pressure while preserving preload reserve.
• In contrast, the attenuated B-receptor response in the elderly during exercise stress is associated with
› (1) decreased maximal heart rate and
› (2) decreased peak ejection fraction.
• Such decreases cause the increased peripheral flow demand to be met primarily by preload reserve, thereby making the heart more susceptible to cardiac failure.
What two important changes in the autonomic nervous system (ANS) take place with aging?
• The two most important changes in the autonomic nervous system with aging are
› a decrease in response to B-receptor stimulation and
› an increase in sympathetic nervous system activity
What is tumescent liposuction?
• "Tumescent" means distended, especially by fluids or gas, and comes from the same Latin root as "tumor." During tumescent liposuction, a combination of IV fluid, dilute lidocaine 0.05% to 0.1%, and dilute epinephrine 1:1,000,000 (collectively called the wetting solution) is used to emulsify fat, provide anesthesia, and create hemostasis during liposuction.
Identify the ratio of wetting solution to volume of fat to be removed for tumescent liposuction. What is the anesthetic concern with this ratio?
• For tumescent liposuction, a ratio of 1 mL of wetting solution to each mL of fat to be removed is commonly employed.
• With liposuction volumes approaching the 4000- to 5000-mL range (or greater), a chief concern is fluid volume overload. Fluid volume overload may promote hypoxemia, hypertension, and/or postoperative pulmonary edema.
What accounts for up to 25% of deaths during liposuction?
• Pulmonary embolism is responsible for approximately 25% of liposuction deaths
Clinical improvement following an epidural steroid injection correlates with three (3) pathophysiologic findings at the nerve root. What are these 3 findings?
• Epidural steroid injection provides relief from acute radicular pain when the nerve root(s) exhibits:
› (1) edema,
› (2) inflammation, and
› (3) increased levels of phospholipase A2 (PLA2) expression.
Which nerve fibers appear to be affected by epidural steroids? (Hint: A-alpha, A-beta, A-gamma, etc..
• Local application of methylprednisolone was found to reversibly block transmission in the unmyelinated C-fibers, but not in AB-fibers.
Identify the two types of complex regional pain syndrome (CRPS); what are the former names for each of the two types of CRPS?
• There are two types of complex regional pain syndrome (CRPS).
› CRPS type I was originally termed reflex sympathetic dystrophy
› CRPS type II represents causalgia
List the signs and symptoms of complex regional pain syndrome (CRPS).
• The signs and symptoms of both types of complex regional pain syndrome (CRPS) include spontaneous pain, hyperalgesia, allodynia (not restricted to a single nerve territory), plus trophic, sudomotor (sweat gland activity), vasomotor abnormalities, and active & passive motor disorders. Sympathetic dysfunction can present as edema and cyanosis.
Since the signs and symptoms of complex regional pain syndrome type I and type II are identical, what differentiates CRPS type I from type II?
• The clinical features of CRPS types I and II are the same, except there is a documented nerve injury preceding CRPS type II.
What is the medical management and treatment of complex regional pain syndrome (CRPS) in a child?
• The mainstay treatment of CRPS in children is physical therapy.
• However, the pain can be severe and disabling enough to prevent active participation by the child in the physical therapy program. Frequently, pharmacologic adjuvant therapy is initiated at first to control symptoms, which is shortly followed by the active physical therapy. Membrane stabilizers (gabapentin) are usually the drug of first choice, accompanied by tricyclic antidepressants.
What regional block may be indicated for circulatory insufficiency of the upper extremity or for relief from complex regional pain syndrome (CRPS) I or II affecting the upper extremity?
• Stellate ganglion block (cervicothoracic sympathetic block) may be indicated for circulatory insufficiency of the upper extremity or for relief from complex regional pain syndrome (CRPS) I or II affecting the upper extremity.
What procedure is generally effective for symptomatic relief of acute radiculopathy (nerve root compression)?
• Epidural steroid injections are effective for relief of pain associated with acute radiculopathy (nerve root compression).
With respect to the onset of acute radiculopathy, what appears to be the optimal time frame for epidural steroid injection? For how long can an epidural steroid injection be expected to provide pain relief from acute radiculopathy?
• Epidural steroid injections are most effective when given within 2 weeks of onset of pain and do not appear to provide long-term pain relief beyond 3 months.
Identify the two most commonly used steroidal agents and their dosing for epidural steroid injections. In what kind of mixture is the steroid often injected?
• The two most commonly used agents for epidural steroid injection are methylprednisone acetate (Depo-Medrol) 40-120 mg, and triamcinolone diacetate (Aristocort), 40-80 mg.
• The steroid is injected either alone, with a saline diluent, or in mixture with a local anesthetic.
What advantages do a local anesthetic and steroid mixture provide for an epidural steroid injection? What are the disadvantages of administering the local anesthetic in combination with the steroid?
• A mixture of local anesthetic and steroid for the epidural injection may be helpful if the patient has muscle spasm and the local anesthetic provides immediate pain relief until the steroid's anti-inflammatory effects take place (12-48 h).
• Injection of a local anesthetic carries the risks of intrathecal, subdural, and intravascular complications, such as hypotension, arrhythmia, and seizure.
Neurolytic blocks are not permanent because of the agents used to temporarily destroy nerve fibers or neural ganglia. Identify the 2 agents most commonly used to perform neurolytic block and the appropriate concentration for each agent.
• Temporary destruction of nerve fibers or ganglia is typically accomplished by injection of alcohol (50-100%) or phenol (6-12%).
• Ethyl alcohol causes temporary destruction of nerve fibers or ganglia by causing extraction of membrane phospholipids and precipitation of membrane proteins.
• Phenol appears to cause temporary destruction of neural tissue by coagulation of proteins.
List three (3) approaches to the epidural space for an epidural steroid injection. What is the recommended volume for injection for each route?
• The epidural space can be approached through the interlaminar space (median or paramedian), the intervertebral foramen (transforaminal, "selective nerve block), or the sacral hiatus (caudal).
› When using a caudal approach, 20 to 25 mL of a solution has been recommended to assure epidural spread cephalad to the desired level.
› When using a lumbar interlaminar approach, a volume of 5 to 10 mL has been recommended to reach those areas most commonly involved in the lumbar region.
› A volume of 2-3 mL is used for the transforaminal approach.
Which of the three approaches to an epidural steroid injection requires the use of radiographic imaging for needle placement?
• The transforaminal (selective nerve block, intravertebral) approach requires the use of radiographic imaging if it is to proceed with safety.
What is the primary indication for a neurolytic block?
• Neurolytic blocks are indicated for patients with severe, intractable cancer pain.
Are neurolytic blocks permanent or temporary?
• Neurolytic blocks are not permanent. They last from 2-6 months
What procedure should be done prior to a neurolytic block?
• At least one diagnostic block with a local anesthetic should be done before considering any neurolytic technique. This serves to confirm the pain pathways involved and to determine the potential efficacy of the neurolytic block.
What is the most effective measure for pain control associated with pancreatic cancer?
• Celiac plexus block with alcohol or phenol is the most effective intervention for treating pain associated with pancreatic cancer.
Identify the 4 most common neurolytic blocks performed in cancer patients with intractable pain.
• The 4 most commonly employed neurolytic blocks in cancer patients with intractable pain are:
› (1) celiac plexus;
› (2) lumbar sympathetic chain;
› (3) hypogastric plexus; and,
› (4) ganglion imparretroperitoneal plexus.
• Neurolytic techniques are sometimes used for somatic or cranial nerves or even neuraxial blocks.
What nerves when blocked may provide relief from cluster headaches? Block or ablation of which nerve ganglion may provide relief from cluster headaches?
• The greater occipital nerve block is commonly used for primary headache syndromes; for chronic syndromes, the anterior region involving the trigeminal nerve is also blocked. It has been reported for use with cervicogenic headache, occipital neuralgia, migraine, and cluster headache. Sphenopalatine ganglion neurolytic block can be used to treat headache and facial pain.
What is the most common cause of malpractice claims against anesthesiologists?
• Tooth damage is the most common cause of practice claims against anesthesiologists
Identify the four (4) elements comprising the "anatomy of medical negligence action."
• In a medical negligence action, the plaintiff must prove to the court the following four elements.
› (1) Duty: reasonable care, as defined by the Standard of Care, is expected.
› (2) Breach of Duty: failure to meet the Standard of Care.
› (3) Damage: the plaintiff must have suffered some injury, either physical or emotional.
› (4) Cause: the damage the plaintiff received was caused by the defendant that deviated from the Standard of Care. There must be a direct or actual cause between the practitioner's actions and the damage the plaintiff received. The plaintiff must also prove proximate cause.
Define "proximate cause."
• A proximate cause is a cause that was foreseeable before the event took place. An alternate definition of proximate cause is that which when viewed in retrospect is not thought of as extraordinary.
Describe two (2) common tests used to establish causation.
• There are two common tests employed to establish causation. The first is the but for test, and the second is the substantial factor test.
• If the injury would not have occurred but for the action of the defendant, or if the act of the defendant was a substantial factor in the injury despite other causes, then proximate cause is established.
In noncriminal tort cases, what is the name for the party who alleges having been harmed?
• In a noncriminal tort case, the party who alleges having been harmed is called the plaintiff.
In noncriminal tort cases, what is the name for the party who is accused of causing the harm to the plaintiff?
• In a noncriminal tort case, the party who is accused of causing harm to the plaintiff is called the defendant.
List four characteristics of research.
• Research can assume many different forms.
• Research should be valid, both internally and externally.
• Research must be reliable, which refers to the extent to which data collection, analysis, and interpretation are consistent and to which the research can be replicated.
• And finally, research must be systematic
Identify the eight (8) stages of the research process.
• The research process is defined as consisting of the following eight distinct stages:
› (1) identification of the problem;
› (2) review of the relevant knowledge and literature;
› (3) formulation of the hypothesis or research question;
› (4) development of an approach for testing the hypothesis;
› (5) execution of the research plan;
› (6) analysis and interpretation of the data;
› (7) dissemination of the findings to interested colleagues; and
› (8) evaluation of the research report.
Define "hypothesis." What does a hypothesis establish?
• In its most elemental form, a hypothesis is either a proposition of the solution to a problem or a stated relationship among variables.
• A hypothesis establishes and defines the independent variable (the variable to be manipulated or is presumed to influence the outcome) and the dependent variable (the outcome that is dependent upon the independent variable).
• The hypothesis is declarative in structure.
State three (3) forms a hypothesis may take.
• A hypothesis may be a directional hypothesis. A directional hypothesis will include the words less or more.
• A nondirectional hypothesis states there is a difference without specifying the direction of the difference.
• The third type of hypothesis is the null hypothesis, which states there is no difference in the relationship or proposed solutions to the problem.
There are many ways to classify research methods. One of the more popular categorizations is to separate the methods into observational and experimental (interventional) studies. Briefly describe each method.
• Observational studies are those in which data is gathered without performing and specific intervention affecting the assignment of groups or effects on group members.
• In an experimental study, subjects are assigned to groups, an intervention(s) is performed, and attempts are made to eliminate bias and confounding variables before the data are collected.
Observational studies may be classified as case-series, case-control, cross-sectional, or cohort studies. Describe a case-series.
• In a simple case-series, the author describes some interesting or intriguing observations that occurred for a small number of patients. There are no control subjects, thus the case-study does not have the nature of "proving" something, but often leads to a hypothesis and subsequent investigation.
How do case-control and cohort studies differ?
• Cohort and case-control studies are called longitudinal studies because they are involve an extended period of time defined by point when the study begins and the point when it ends.
› A case-control study begin "at the end" with the presence or absence of an outcome and then looks backward in time to try to detect possible causes or risk factors that may explain the outcome. Therefore, a case-control study is a retrospective study that asks, "What happened?"
› In a cohort study, the researchers select group of people who have something in common, say a risk factor, and then monitor the cohort forward in time. A cohort study asks, "What will happen?" and thus is a prospective study.
What is "bias" in a research method?
• Bias is a systematic effect in the study that produces an error on our interpretation of the results. Several types of bias exist; some of the more common biases are: selection bias, confounding bias, and measurement bias.
Describe selection bias.
• Selection bias occurs when two groups are compared with respect to some variable without acknowledging or realizing that the groups are different in other important ways.
Define confounding bias.
• Confounding bias occurs when multiple variables are intertwined so that although we may assume the variable under study is important, the truth is that the confounding variable may be more important.
Describe measurement bias.
Measurement bias occurs if the methods used for making measurements when comparing different groups have different scales or sensitivities.
• Measurement bias may be avoided in a blinded study.
What does the term blinding refer to? What may be avoided by doing a blinded study?
• The term blinding (or masking) refers to the process of controlling for obvious and occult biases arising from the subjects' or researchers' reaction to what is taking place.
• In a blinded (or masked) study, measurement bias may be avoided if the person performing the measurement does not know which group is being measured. This is called a single-blind study.
• In a double-blind study, neither the researcher nor the subject is aware of which treatment or manipulation the subject is receiving. In either blinded study, measurement bias is avoided.
As with research study design methods, there are many ways to categorize types of data and measurements. Nagelhout categorizes data in 4 categories. List the four categories of measurement/data types.
• The four levels or degrees of measurement or data types are: nominal, ordinal, interval, and ratio. For reference, one of the other popular categorization of measurements is: nominal, ordinal, and numerical. Nominal and ordinal measurements are often called qualitative observations, whereas interval and ratio measurements are called quantitative observations. Both interval and ratio measurements are continuous in nature.
Give the characteristics of nominal measurements and some examples of nominal data.
• Nominal scales are used for the simplest types of data that fit into categories.
• Nominal measurements simply identify the data.
• If there are only two categories of data, for example male and female, the observations are binary or dichotomous.
• An example of observations with more than two categories would be blood types (A, B, AB, O) and eye color (brown, green, blue).
Give the characteristics of ordinal measurements and some examples of ordinal data.
• With ordinal measurements, observations are still classified by categories, but some observations may have more or are greater than other observations, and thus are ordered or ranked.
• Examples of ordinal data include order of race finish (1st, 2nd, 3rd, etc.), pain scores, and the ASA classification scheme (ASA Class I, ASA Class II, etc.).
• ORDinal = ORDer
Give the characteristics of interval measurements and some examples of interval data.
• Interval observations measure the quantity of something for which the differences between the numbers have meaning on a numerical scale built upon equally spaced intervals. Technically, interval data does not have an absolute zero point on the scale.
• Examples are temperature on the Fahrenheit or Celsius scales, calendar years, or the IQ scale.
• The distance (interval) between adjacent measurements is meaningful and quantifiable, not simply "more" or "less."
Give the characteristics of ratio measurements and some examples of ratio data.
• Ratio measurements are quantitative, numerical observations that can be ordered and equally spaced, but which are based upon a numerical scale that has an absolute zero point.
• Examples of ratio data are the temperature on the Kelvin scale (absolute temperature), blood pressure, distance, age, volume, and height.
What is operationalization?
• Operationalization is the process of making the characteristics inherent in a given variable, condition, or process clear and familiar to others. For example, if a study examined critically ill patients it would be essential to operationalize the term "critically ill patients" in order to clearly delineate the term so that the research might be replicated without change.
List three different classes of statistical techniques used to analyze and interpret research data.
• Once the observations have been collected, they are often categorized and described by descriptive statistical techniques. If a relationship between data has been hypothesized, correlational statistical techniques may be used to describe the extent to which two (or more) variables are related to each other or for quantifying the degree of that relationship. Finally, inferential statistical techniques provide a set of procedures that allow the researcher to infer that the events observed in the sample will also occur in the larger unobserved population from which the sample was obtained.
What are the population and the sample in statistical terms?
• The population refers to any target group of things (animate or inanimate) in which there is interest. The population is the entire collection of observations or subjects that have something in common and to which conclusions are inferred.
• A sample is a subset of the target population. Samples are taken because of the impossibility of observing the entire population; it is generally not affordable, convenient, or practical to examine more than a relatively small fraction of the population.
What is a "distribution"? Describe the Normal distribution.
• The group or set of all the observations of a variable along with the frequency of their occurrence and placement of the values is called the distribution of the variable. A distribution may be based on empirical observations or may be a theoretical probability distribution that is defined by an algebraic equation. The most important distribution is the Normal distribution, also called the Gaussian or bell-curve distribution.
Why is the normal distribution so important the biological and medical research methods?
• The Normal distribution is important because it has been empirically noted that when a biologic variable is sampled repeatedly, the pattern of the numbers plotted as a histogram resembles the normal curve; thus, most biologic data are said to follow or to obey a normal distribution. Equally important, a mathematical theorem (the central limit theorem) allows the use of the assumption of Normality for certain purposes, even if the population is not Normally distributed.
List the three descriptive statistics that specify the central tendency, or middle, of numerical data.
• The median is the center or middle data point if the data can be ordered (ranked) from smallest to largest. The median is the point at which half the observations are smaller, half are larger. The mode is the most frequently occurring value. The mean is the arithmetic average of the numerical observations in a sample. The mean is symbolized by x-, called X-bar.
On addition to describing the central tendency of the data distribution, we also need to characterize the spread or variability of a data sample. What two measures describe the spread or variability of data (hint: variability = deviation)?
• The spread, dispersion, or variability of data is described by the range and the variance Q standard deviation.
• The range is simplest the difference between the largest and smallest observation.
• The standard deviation is a measure of the spread of the data about their mean. The standard deviation measures the "average" spread of the observations about the mean. The variance is the square of the standard deviation and its mathematical derivation and rationale is beyond the scope of this resource.
Inferential statistical techniques are either parametric or nonparametric. Define these terms.
• When data follow a normal distribution, the methods of parametric statistics can be used. The term parametric refers the ability to describe the distribution with a specific set of values, or parameters. For the Normal distribution, only two parameters are required to define and describe the distribution: the mean and the standard deviation. If it is not possible to describe the data with a set of parameters, nonparametric statistical methods are required.
What is the first question to ask in choosing a statistical test?
• The first question to ask in considering the choice of a statistical test is to decide whether statistical methods that assume a Normal distribution (parametric) are appropriate, or whether nonparametric methods are needed (data is not Normally distributed).
What is the second question to ask in choosing the appropriate statistical test?
• The second question to ask when choosing between statistical tests is "how many groups are being compared?" There may be one group, two groups, or multiple groups to characterize.
What is the third question to ask in choosing the appropriate statistical test, based upon two or more groups?
• The third question to ask in choosing a statistical test is "are the data in the groups paired or unpaired?" A key to answering this question is to ask "were the same individuals studied before and after some intervention or condition?" If the answer is "yes, the same individuals were studied before and after an intervention" then these are paired data groups not independent groups.
Which statistical test compares the difference between the means of Normally distributed interval or ratio data from two independent groups?
• The unpaired (two-sample) Student's t test is used to compare the difference between the means of two independent groups, provided the observations are Normally distributed interval measurements.
Describe the appropriate application of the paired Student's t test.
• Given Normally distributed interval or ratio data, the paired t test (also called a t test, dependent samples) evaluates the difference between dependent, paired sample (for example pretreatment and post-treatment) outcomes.
Given nonparametric nominal data from two or more independent samples (groups), which statistical test evaluates the difference between observed and expected frequencies?
• The Chi-squared analysis of contingency tables evaluates the difference between observed and expected frequencies from nominal or ordinal data that are not necessarily Normally distributed.
Which nonparametric test is the equivalent of the unpaired t test for nonparametric ordinal data?
• The Mann-Whitney rank sum test tells whether medians between two independent nonparametric groups of ordinal data are different. After individual observations are ranked, the ranks are analyzed just as though they were the original data. The various incarnations of the general rank sum test are often used by researches in the health field for nonparametric data.
Which parametric test evaluates the difference among the means of interval or ratio data from more than two independent groups or more than one independent variable?
• An analysis of variance (ANOVA) tests the difference among the means of more than two independent groups or more than one independent variable given Normally distributed interval or ratio data.
What is the appropriate statistical test to determine whether one variable x (the independent variable) predicts the outcome of another variable y (the dependent variable).
• Simple linear regression evaluates the association between two parametric, numeric variables. Linear regression produces an equation in the form of y = mx + b that allows predication of the outcome variable y (the dependent variable) given the predictor variable x (the independent variable).
Define "standard of care."
• The standard of care is the conduct and skill of a prudent practitioner that can be expected by a reasonable patient. Standard of care is also defined as reasonable care by a professional. (Nagelhout).
• Standard of care is a very important medicolegal concept because a bad medical result due to failure to meet the standard of care is malpractice.
How is the standard of care established? What two sources are typically consulted to establish the standard of care?
• Ultimately, the standard of care is what a jury says it is (Barash). There are two main sources of information as to exactly what is the expected standard of care. Traditionally, the beliefs offered by expert witnesses in medical liability lawsuits regarding what is actually being done in real life (de facto standards of care) were the main input juries had in deciding what was reasonable to expect from the defendant.
• The second, much more objective, source for defining certain component parts of the standard of care is the published standards of care, guidelines, practice parameters, and protocols now becoming more common. These serve as hard evidence of what can be reasonably expected of practitioners and can make it easier for a jury evaluating whether a malpractice defendant failed to meet the applicable standard of care.
What agency sets and enforces quality standards for ambulatory surgical facilities?
• Quality standards are set and enforced either by government regulation, through a licensing process, or by accreditation by private organizations such as the Accreditation Association for Ambulatory Health Care (AAAHC). The AAAHC is an independent accreditation organization whose principle activities are to develop standards, conduct surveys, and confer accreditation on ambulatory health care providers. In the United States and Canada, hospital-based ambulatory surgical facilities receive accreditation through The Joint Commission (formerly JCAHO).
What are the first two actions to take in an airway fire? What are the next actions?
• The first action in an airway fire is to simultaneously stop ventilation and remove the endotracheal tube, followed immediately by turning off and disconnecting the oxygen. The sequence of subsequent actions varies (different references give slightly different orders) but includes: pour saline into airway; remove burning materials; mask ventilation and reintubation; diagnose the injury, treat by bronchoscopy and laryngoscopy; administer short-term steroids; monitor the patient for at least 24 hours; and, administer antibiotics and provide ventilatory support as necessary.