What are the gastrointestinal and hematologic derangements that occur with cirrhosis

G Il complications result from portal hypertension (> 10 mm Hg). Portal hypertension leads to the development of portosystemic venous collaterals, including esophagogastric varices. Ruptured varices with hemorrhage account for one third of the mortality in patients with cirrhosis. Hematologic disorders include anemia, thrombocytopenia and coagulopathy. Anemia is secondary to GI bleeding, malnutrition, and bone marrow suppression. Thrombocytopenia is caused by splenic sequestration, bone...

Increased intracranial pressure s and traumatic brain injury

Define elevated intracranial pressure. Elevated intracranial pressure (ICP) is usually defined as a sustained pressure of greater than 20 mm Hg within the subarachnoid space. The normal ICP is approximately 10 to 18 mm Hg. 2. What are the determinants of intracranial pressure The space-occupying contents of the skull, the brain (85 ), the cerebrospinal fluid (CSF) (10 ), and cerebral blood volume (15 ), are all contained in the virtually fixed volume of the cranium. Once compensatory mechanisms...

What peripheral nerve block can be performed for surgery of the lower extremity

The first step in deciding what block is indicated for anesthesia or analgesia is appreciating the innervation of the lower extremity and the requirements of the proposed procedure. The lumbar plexus (L1-L4) gives origin to the ilioinguinal, genitofemoral, obturator, femoral, and lateral femorocutaneous nerves and mainly innervates the inguinal region and the anterior aspect of the thigh. The rest of the lower extremity is innervated by the sacral plexus. This includes the posterior aspect of...

Describe the pulmonary artery waveform

Perhaps the most noticeable change as the catheter tip enters the PA is the upstroke in diastolic pressure (Figure 26-2). Other features include a rapid upstroke, a progressive diastolic runoff, and a dicrotic notch secondary to pulmonic valve closure (Figure 26-3). Peak systole is found after the QRS complex but before the peak of the T wave. End diastole is found near the end of the QRS complex. Figure 26-2. Diastolic pressure increases as the pulmonary artery (PA) catheter tip crosses from...

What is diastolic dysfunction

Diastolic dysfunction can occur with normal LV EF in many patients. Impaired LV relaxation or compliance or both are the major characteristic features of LV diastolic dysfunction. Early diastolic filling depends on the rapidity of ventricular relaxation, characterized by an Figure 34-1. Left ventricular (LV) pressure-volume loops illustrating normal performance (loop 1), diastolic (loop 2), and systolic dysfunction (loop 3). AB, Diastolic filling BC, isovolumic contraction CD, ejection DA,...

Degenerative neurologic diseases and neuropathies

What is amyotrophic lateral sclerosis and its anesthetic considerations Also known as Lou Gehrig's disease, amyotrophic lateral sclerosis (ALS) is a disease of both upper and lower motor neurons. It usually affects men in the fourth or fifth decade of life. Patients with ALS develop progressive weakness and eventually die (from pneumonia and pulmonary failure), often in a 3- to 5-year period. Although extremities are involved first, eventually bulbar muscles become affected, increasing the risk...

Describe the functionally distinct compartments of body water using a 70kg patient for illustration

Accurate estimations are difficult because ordinarily ideal body weight (IBW) is used as a basis for calculation. Obesity is rampant in our society, making accurate estimations difficult. Figure 4-1 estimates body water compartments in a patient with an IBW of 70 kg. Compartment percent of total body weight Figure 4-1. Body water compartments in a patient with an ideal body weight of 70 kg. BV, Blood volume ECF, extracellular fluid ICF, intracellular fluid ISF, interstitial fluid.

How often does the preoperative evaluation alter care plans

It has been found that care plans were altered in 20 of all patients (including 15 of American Society of Anesthesiologists ASA class 1 and 2 patients) because of conditions identified at the preoperative evaluation. The most common conditions resulting in changes were gastric reflux, insulin-dependent diabetes mellitus, asthma, and suspected difficult airway. These findings indicate that, whenever possible, it is preferable in all patients to do the preoperative evaluation before the day of...

How does prone ventilation improve oxygenation

The primary pulmonary defect based on computed tomographic scans of supine patients with ARDS is the opacification of the gravity-dependent areas of the lung as a result of atelectasis and consolidation. Clearly alveolar flooding from formation of edema fluid is partially responsible for the atelectasis, but mechanical imbalances caused by cephalic displacement of Sustained inflation CPAP a CPAP of 30-40 cm H2O High-frequency ventilation High-frequency oscillation Use reverse Trendelenburg...

Key Points Perioperative Hepatic Dysfunction

Patients with end-stage liver disease have a hyperdynamic circulation with increased cardiac output and decreased systemic vascular resistance. 2. Although the portal vein supplies up to 75 of total hepatic blood flow, only 45 to 55 of the oxygen requirements are provided by this part of the circulation. 3. Because of the large reserve of the liver, significant impairment of physiologic function must occur before clinical signs and symptoms of hepatic failure become evident. 4. Because of...

Outline the initial management of an unconscious hypotensive patient

The ABCs (airway, breathing, and circulation) are essential. Unconscious patients require rapid and definitive airway control. The trachea should be intubated in a rapid-sequence fashion. Establish numerous large-gauge sites of intravenous access, using either short 14-or 16-G catheters peripherally or 9 Fr introducers into the central circulation. Quickly bolus the patient with at least 2 L of balanced crystalloid solution. Failure to respond indicates a need for blood. If crossmatched blood...

Relate the advantages and disadvantages of spinal anesthesia for cesarean section Which drugs are frequently used in

Spinal anesthesia produces a dense neural blockade it is relatively easy to perform, has a rapid onset, and carries no risk of local anesthetic toxicity. The development of small-gauge, noncutting needles has significantly reduced the incidence of postdural-puncture headache (PDPH) to 1 or less. Hypotension can be treated by rapid hydration (1 L colloid or 1 to 2 L crystalloid), positioning to avoid aortocaval compression, and use of phenylephrine (50 to 100 mcg) or ephedrine (5 to 10 mg IV) if...

Relative contraindications

Advanced chronic renal failure Age > 60 years Portal vein thrombosis Cholangiocarcinoma Hypoxemia with intrapulmonary right-to-left shunts Hepatitis HBsAg and HBeAg positivity HIV positivity without clinical AIDS Modified from Maddrey WC, Van Thiel DH Liver transplantation an overview, Hepatology 8 948,1988. AIDS, Acquired immunodeficiency syndrome HIV, human immunodeficiency virus. syndrome), hepatic disease may be overshadowed by the severity of the comorbid conditions. Prior abdominal...

Renal function and anesthesia

The kidneys are paired organs lying retroperitoneally against the posterior abdominal wall. Although their combined weight is only 300 g (about 0.5 of total body weight), they receive 20 to 25 of the total cardiac output. The renal arteries are branches of the aorta, originating below the superior mesenteric artery. The renal veins drain into the inferior vena cava. Nerve supply is abundant sympathetic constrictor fibers are distributed via celiac and renal...

Review the alleged benefits and risks of ginkgo

Ginkgo is used for the treatment of dementia, Alzheimer's disease, and conditions associated with cerebral vascular insufficiency, including memory loss, headache, tinnitus, vertigo, difficulty concentrating, mood disturbances, and hearing disorders. Active ingredients of ginkgo leaf and its extracts include flavonoids, terpenoids, and organic acids. Although the mechanism of action is only partially understood, there are several theories about how ginkgo works. Ginkgo may protect tissues from...

Review the anatomy of the sympathetic nervous system

Preganglionic sympathetic neurons originate from the intermediolateral columns of the thoracolumbar spinal cord. These myelinated fibers exit via the ventral root of the spinal nerve and synapse with postganglionic fibers in paravertebral sympathetic ganglia, unpaired prevertebral ganglia, or a terminal ganglion. Preganglionic neurons may ascend or descend the sympathetic chain before synapsing. Preganglionic neurons stimulate nicotinic cholinergic postganglionic neurons by releasing...

Review the classifications of memory and awareness

The current classifications of memory include both implicit, or unconscious memory, and explicit, or conscious memory. Explicit memory refers to the conscious recollection of specific intraoperative events that took place during general anesthesia, also called anesthetic awareness. Recall can only be determined after surgery. These memories can occur with or without pain and can range from vivid recollections to vague memories. It was reported in 2008 that subjective auditory perceptions...

Review the clinical features of total spinal anesthesia

Total spinal anesthesia results from local anesthetic depression of the cervical spinal cord and brainstem. Signs and symptoms include dysphonia, dyspnea, upper extremity weakness, loss of consciousness, pupillary dilation, hypotension, bradycardia, and cardiopulmonary arrest. Early recognition is the key to management. Treatment includes securing the airway, mechanical ventilation, volume infusion, and pressor support. The patient should receive sedation once ventilation is instituted and the...

Review the synthesis of dopamine norepinephrine and epinephrine

The amino acid tyrosine is actively transported into the adrenergic presynaptic nerve terminal cytoplasm, where it is converted to dopamine by two enzymatic reactions hydroxylation of tyrosine by tyrosine hydroxylase to dopamine and decarboxylation of dopamine by aromatic Bronchioles Salivary glands Intestine contractility, conduction velocity Constriction Stimulates secretion Contraction and relaxation of Nicotinic Neuromuscular junction Autonomic ganglia sphincters, stimulates secretions...

Should children with upper respiratory infection receive general anesthesia

The risk of adverse respiratory events is 9 to 11 times greater up to 6 weeks after an upper respiratory infection (URI). Underlying pulmonary derangements include decreased diffusion capacity for oxygen, decreased compliance, increased airway resistance, decreased closing volumes, increased shunting (ventilation-perfusion mismatch), hypoxemia, and increased airway reactivity (desaturation, bronchospasm, laryngospasm). Associated factors predicting an increased likelihood of perioperative...

Since these medications appear to impair coagulation how can their effect be evaluated clinically

The best means for detecting a coagulation defect secondary to herbal medications is a properly taken clinical history. Especially important are questions related to the hemostatic response during previous surgeries. Also important are questions regarding bleeding tendencies such as easy bruising, gingival bleeding, or excessive bleeding following procedures such as dental extractions. Positive responses suggest the need for laboratory testing. The most commonly used measures of coagulation...

Trace the neurosensory pathway from the peripheral nerves to the cerebral cortex

The axons of the peripheral sensory nerves enter the spinal cord via the dorsal spinal roots. These first-order neurons continue rostrally in the ipsilateral posterior column of the spinal cord until they synapse with nuclei at the cervicomedullary junction. Second-order neurons from these nuclei immediately decussate to the contralateral side of the brainstem, where they continue their ascent via the medial lemniscus through the midbrain, synapsing in the thalamus. Third-order neurons then...

What are the advantages and disadvantages of cesarean section with epidural anesthesia vs spinal anesthesia What are

If epidural analgesia is used for pain relief during labor and delivery, higher concentrations of local anesthetics can provide surgical anesthesia. The local anesthetic should be given in increments, titrating to the desired sensory level. Titration of local anesthetic results in more controlled sympathetic blockade thus the risk of hypotension and reduced uteroplacental flow may be decreased. Typically epidural anesthesia produces less intense motor and sensory blockade than spinal...

What are the alleged benefits and risks of ginseng

Ginseng is a general tonic for improving well-being and stamina and may increase resistance to environmental stress. The active constituents of ginseng are ginsengosides these compounds may raise blood pressure and act as a central nervous system stimulant. Adrenal function and cortisol release may increase. Ginsengosides are reported to interfere with platelet aggregation and coagulation in vitro, but this effect has not been demonstrated in humans. Ginseng is also associated with...

What are the anesthetic considerations in patients with preeclampsia

Before initiation of neuraxial anesthesia, evaluation of coagulation status is recommended. Because thrombocytopenia is the most common coagulopathy in preeclampsia, a screening platelet count is recommended. Although an arbitrary platelet count of 100,000 is often suggested, the actual platelet count safe for spinal or epidural placement is unknown. Spinal anesthesia has been controversial in patients with severe preeclampsia because of the potential risk of sudden hypotension with rapid onset...

What are the characteristics of a left bundlebranch block

In V1 there is a broad, deep S wave (or QS wave), with ST segment elevation, that may be preceded by a very narrow R wave (Figure 22-2). In lead I there is a broad R wave (sometimes notched) without a Q or S wave. Figure 22-2. Typical appearance of a left bundle-branch block in V1. In some cases a narrow R wave precedes the large monomorphic S wave. Figure 22-2. Typical appearance of a left bundle-branch block in V1. In some cases a narrow R wave precedes the large monomorphic S wave. The left...

What are the clinical risk factors for a major perioperative cardiac event

The Revised Cardiac Risk Index (Table 17-4) has six components history of ischemic heart disease, history of congestive heart failure, history of cerebrovascular disease, preoperative treatment with insulin, surgical risk, and elevated preoperative serum creatinine. The patient is assigned one point for each of these risk factors, which are then translated into percentage risks of perioperative major cardiac events such as myocardial infarction, pulmonary edema, ventricular fibrillation,...

What are the concerns for patient positioning during a craniotomy

Because craniotomies tend to be lengthy procedures, protecting vulnerable peripheral nerves and pressure-prone areas from injury is essential. Provisions must be made to prevent preparation solutions from entering the eyes. Generally the head is fixed in position with pins clamped against the outer table of the skull. Because the head is held in a fixed position, any patient movement will stress the cervical spine. Muscle paralysis must be maintained all the time the head is secured in the...

What are the most common complications of spinal anesthesia

Common complications include hypotension, bradycardia, increased sensitivity to sedative medications, nausea and vomiting (possibly secondary to hypotension), postdural puncture headache (PDPH), and residual back pain and paresthesias (usually associated with the use of lidocaine. Less frequent but more ominous complications include nerve injury, cauda equina syndrome, meningitis, total spinal, and hematoma abscess formation. Particular issues associated with these complications are discussed...

What are the most commonly used parenteral opioids for labor analgesia Which side effects are of special concern to the

Table 60-1 summarizes commonly used parenteral opioids and their side effects. In general, intravenous medications help the parturient tolerate labor pain but do not provide complete analgesia. The incidence of side effects and efficacy of analgesia are dose dependent. Maternal sedation and nausea are common. Opioids easily cross the placenta and may cause a decrease in fetal heart rate variability. In addition, intravenous opioids may cause neonatal respiratory depression and neurobehavioral...

What challenges do spinal cordinjured patients pose

Airway management has been discussed briefly. The technique of choice depends on the urgency of the situation but might be direct laryngoscopy with in-line stabilization, intubation using a Bullard laryngoscope, or fiberoptic intubation. When moved, patients should be log-rolled that is, rolled and moved with care to maintain the neck in a neutral position. Some degree of neurogenic shock should be expected with injuries above the T6 level. However, hypotension in cord-injured patients is most...

What factors may predispose a patient having spine surgery to postoperative visual loss

The causative factors associated with POVL after spine surgery are not fully understood. The incidence appears to be about 0.2 . The ASA has developed a visual loss registry in an effort to identify predisposing factors and make recommendations to reduce the incidence of this tragic complication. It is thought that there is a subset of patients at high risk for this complication, although it is not always possible to identify before surgery which patients are at high risk. These patients may...

What is a combined spinalepidural anesthetic Why use both

For a combined spinal-epidural anesthetic, a long spinal needle is passed through an epidural needle that has been placed in the epidural space, and the dura is punctured. When CSF is obtained from the spinal needle, a dose of local anesthetic is placed in the subarachnoid space, and the spinal needle is removed. The epidural catheter is then threaded into the epidural space, and the epidural needle is removed. This technique combines the advantages of both spinal and epidural anesthesia fast...

What is considered a safe increase in intraabdominal pressure

The current recommendation for intra-abdominal pressure (IAP) during laparoscopy is less than 15 mm Hg, and most laparoscopic procedures are performed with IAPs in the 12-to 15-mm Hg range. In general IAPs less than 10 mm Hg have minimal physiologic effects. Insufflation pressures above 16 mm Hg result in undesirable physiologic changes (i.e., decreased CO, increased systemic vascular resistance SVR and decreased compliance of the lung and chest wall). At pressures greater than 20 mm Hg, renal...

What is HELLP syndrome

HELLP syndrome (hemolysis, elevated liver enzymes, and low platelet count) is a complication of preeclampsia. Patients develop a microangiopathic hemolytic anemia associated with thrombocytopenia and elevated liver enzymes. Ten to twenty percent of these patients will have normal blood pressure, making the diagnosis sometimes difficult. Although HELLP syndrome is not an indication itself for immediate cesarean delivery, delivery is the only definite treatment for preeclampsia. Patients who...

What is the risk of neurologic injury after spinal anesthesia

Direct trauma to nerve fibers may occur from the spinal needle and may be heralded by a paresthesia, for which the spinal needle should be redirected. Hematoma formation from epidural venous bleeding (from direct trauma or coagulopathy) or abscess formation is suggested by persistent neurologic deficits or severe back pain. Early recognition and management are imperative to avoid permanent neurologic sequelae. In patients who have received any medication with anticoagulant potential, it is...

What is the significance of autonomic dysfunction How might you tell if a patient has autonomic dysfunction

Patients with autonomic dysfunction tend to have severe hypotension intraoperatively. Evaluation of changes in orthostatic blood pressure and heart rate is a quick and effective way of assessing autonomic dysfunction. If the autonomic nervous system is intact, an increase in heart rate of 15 beats min and an increase of 10 mm Hg in diastolic blood pressure are expected when changing position from supine to sitting. Autonomic dysfunction is suggested whenever there is a loss of heart rate...

What mechanism of action accounts for the inotropic effect of thyroid hormone

Thyroid hormone affects chronic changes in protein synthesis such as alterations of nuclear synthetic machinery, structural changes of the myosin isozyme, and increased expression of p-adrenergic receptors. In addition, more immediate augmentation of contractility results secondary to an increase in mitochondrial respiration and ATP production, enhanced function of sarcolemmal Ca-ATPase, and augmented sodium entry into myocytes. Elevated intracellular sodium levels increase intracellular...

What medications are useful in treating acute pain

The medications useful in treating acute pain are similar to those used in treating other types of pain. The World Health Organization analgesic ladder developed for treating patients with cancer pain also provides a useful approach to treating acute pain (Figure 77-2). At the lowest level (mild pain), nonopioid analgesics such as nonsteroidal antiinflammatory drugs (NSAIDs) (e.g., ibuprofen or acetaminophen) are useful. Such drugs have an analgesic ceiling above a certain dose no further...

What opioids are used to provide spinal and epidural analgesia during labor Name their most common side effects Do they

The most commonly used neuraxial (spinal and epidural) opioids are fentanyl and sufentanil (Table 60-2). Pruritus, nausea, and vomiting are the most common side effects delayed respiratory depression is the most serious complication, although very uncommon in this OPIOIDS USED TO PROVIDE INTRATHECAL (SPINAL) ANALGESIA population. Intrathecal or epidural opioids alone may provide adequate relief for the early stages of labor, but they are unreliable in producing adequate analgesia for the active...

When treating acute pain in a chronic pain patient how should the approach differ

When a chronic pain patient has suffered an injury or undergone surgery, the general rule is that the typical dose of oral opioids should be tripled for the first 1 to 2 days. In the preoperative preparation for a chronic pain patient, a one-time dose of gabapentin (900 to 1200 mg) or pregabalin (75 to 100 mg) coupled with a one-time dose of celecoxib (Celebrex) (200 mg) has been shown to improve pain control. After surgery gabapentin or pregabalin can be continued as a regular oral dose, and...

Why are patients who have received spinal anesthetics especially sensitive to sedative medications What is

Caplan and associates (1988) published a landmark review of healthy patients who, while undergoing elective surgery using spinal anesthesia, experienced a sleeplike state without spontaneous verbalization followed by respiratory and cardiac arrest. Despite the fact that these were witnessed arrests, the patients were difficult to resuscitate and either died or had severe neurologic deficits. Subsequently it has been determined that patients receiving spinal anesthetics are especially sensitive...

Why is it important to distinguish between polymorphic and monomorphic ventricular tachycardia

The differential diagnosis and treatment for each are somewhat different. Monomorphic VT is common in patients with structural heart disease (such as a previous Q wave myocardial infarction), but it is generally not caused by acute ischemia. Polymorphic VT may be seen in a variety of settings. Patients may have a long QT interval associated with polymorphic VT, commonly referred to as torsades de pointes. This may arise from medications, electrolyte derangements, a congenital predisposition...

How does normal pain perception occur

Nociceptors are structures located at the end of axons that are depolarized by noxious thermal, mechanical, or chemical stimuli. The distal ends of mostA-S and C fibers are nociceptors. These axons are the ones that carry nociceptive information to the dorsal root and trigeminal ganglion and enter the spinal cord via the posterior root. Once in the spinal cord these afferent fibers synapse with cells in Rexed's laminae I and V preferentially but also in laminae II and X. Axons from the...

How does an uncleared cervical spine modify the approach to the airway

Patients requiring emergent surgical procedures do not have time to have their cervical spines evaluated fully. There is no airway management technique that results in no cervical motion. However, there is no documentation of iatrogenic neurologic injury in patients with cervical fractures when cervical spine precautions are used. These precautions include an appropriately sized Philadelphia collar, sand bags placed on each side of the head and neck, and the patient resting on a hard board with...

A patient has a right bundlebranch block that is new compared to the ECG from 2 years ago How should I proceed

Although a RBBB can be caused by CAD (e.g., with a large anterior infarct destroying some of the conduction system in the interventricular septum), this is only true in a minority of RBBB patients. Such patients typically have a qR in V1 instead of an rSR' prime because the initial r wave is lost as a consequence of the MI. Occasionally an RBBB may be caused by congenital heart disease (such as tetralogy of Fallot), prior cardiac surgery, a cardiomyopathy, or pulmonary hypertension. History and...

Do all patients with an accessory pathway have a delta wave WPW pattern on their baseline electrocardiogram

Afib Conduction

Many accessory pathways conduct only in a retrograde fashion (from ventricle to atrium) or have very slow antegrade (atrial to ventricular) conduction. These patients may or may not have narrow-complex SVT (AVRT). In contrast, some patients have a delta wave on the baseline ECG with no clinical symptoms. In many cases these asymptomatic patients do not need pharmacologic treatment or invasive electrophysiologic testing. 26. A 25-year-old patient presenting with palpitations is noted to have...

How can anesthesiologists protect themselves from radiation exposure

Most institutions abide by the ALARA philosophy when it comes to protecting their workers radiation exposure should be kept As Low As Reasonably Achievable. There are three basic strategies to the ALARA philosophy Maximize the distance to the source Newton's inverse square law, which applies to any point source that spreads its influence in all directions (such as light, sound, gravitational field) tells us that the intensity of the radiation at a given radius is the source strength divided by...

Top 100 Secrets

These secrets are 100 of the top board alerts. They summarize the concepts, principles, and most salient details of anesthesiology. 1. Patients should take prescribed p-blockers on the day of surgery and continue them perioperatively. Because the receptors are up-regulated, withdrawal may precipitate hypertension, tachycardia, and myocardial ischemia. Clonidine should also be continued perioperatively because of concerns for rebound hypertension. 2. Under most circumstances peri-induction...

Key Points Concerns In Patients Taking Cocaine

Myocardial ischemia is not uncommon in cocaine-abusing patients, and selective p2-blockade should be avoided because it may cause vasoconstriction and worsen the ischemia. 2. Severe hypertension and tachycardia are risks during airway management unless the patient is deeply anesthetized. 3. Cocaine sensitizes the cardiovascular system to the effects of endogenous catecholamines. Ketamine and pancuronium potentiate the cardiovascular toxicity of cocaine and should be avoided. 26. What is crystal...

What is an acceptable preoperative platelet count

A normal platelet count is 150,000 to 440,000 mm3. Thrombocytopenia is defined as a count of < 150,000 mm3. Intraoperative bleeding can be severe with counts of 40,000-to 70,000 mm3, and spontaneous bleeding usually occurs at counts < 20,000 mm3. The minimal recommended platelet count before surgery is 75,000 mm3. However, qualitative differences in platelet function make it unwise to rely solely on platelet count. Thrombocytopenic patients with accelerated destruction but active production...

Review the pros and cons of induction agents in asthmatic patients

Intravenous induction agents used in asthmatic patients include oxybarbiturates, thiobarbiturates, ketamine, and propofol. Thiobarbiturates constrict airways in laboratory investigations and may have a loose association with clinical bronchospasm. The most common cause of bronchospasm is the stimulus of intubation, and large doses of barbiturates are required to block this effect successfully. Ketamine has well-known bronchodilatory effects secondary to the release of endogenous catecholamines...

What is the significance of portal pulmonary hypertension How are these patients managed in the pretransplant period

In contrast to mosttransplant recipients, portal pulmonary hypertension (PPHTN) patients have an increased risk of death because of right ventricular failure in the peritransplantation period. Physicians are uncertain which PPHTN patients may undergo transplantation because there are no patient characteristics that clearly predict outcome. Patients with moderate to severe PPHTN should not be considered candidates until they undergo a trial of vasodilator therapy. The cause of pulmonary...

Diabetes mellitus

Slover, MD, and Robin Slover, MD 1. Describe the principal types of diabetes mellitus. Type 1 diabetes mellitus An autoimmune disorder in which destruction of the pancreatic islet cells results in the inability to produce insulin. Onset is more common in children and young adults. Type 2 diabetes mellitus A disorder in the body's ability to use insulin. Early in the course of the disease the patient may be able to make sufficient insulin, but cell-receptor impairment results in...

A 3yearold child presents for an elective tonsillectomy His mother reports that for the past 3 days he has had a runny

Viral upper respiratory infection (URI) alters the quality and quantity of airway secretions and increases airway reflexes to mechanical, chemical, or irritant stimulation. Some clinical studies have shown associated intraoperative and postoperative bronchospasm, laryngospasm, and hypoxia. There is evidence that the risk of pulmonary complications may remain high for at least 2 weeks and possibly 6 to 7 weeks after a URI. Infants have a greater risk than older children, and intubation probably...

How long before surgery must a patient quit smoking to realize any health benefits

All patients who smoke should understand that smoking cessation even immediately before surgery has profound, measurable health benefits. Nicotine is a stimulant and has a half-life of only 1 to 2 hours its adverse effects on systolic blood pressure and heart rate can be seen after only 12 hours of smoking cessation. Carbon monoxide (CO), which diminishes oxygen-carrying capacity, has a half-life of only 4 hours. Diminished levels of nicotine and CO were likely behind the outcome of a study...

What are the causes of intraoperative wheezing and the correct responses to asthmatic patients with acute bronchospasm

Causes include airway secretions, foreign body, pulmonary edema (cardiac asthma), obstructed endotracheal tube, endotracheal tube at the carina or down a main-stem bronchus, allergic or anaphylactic response to drugs, and asthma. A number of medications cause wheezing in asthmatic patients, including p-blockers, muscle relaxants, and aspirin. After carefully checking the endotracheal tube and listening for bilateral breath sounds, increase the inspired oxygen to 100 and deepen the anesthetic if...

Alcohol and substance abuse

How is alcohol absorbed and metabolized Alcohol is absorbed across the gastrointestinal mucosa, more so in the small intestine than in the stomach. The volume of distribution (Vd) of alcohol is that of body water. Alcohol easily crosses the blood-brain barrier. Arterial blood levels of alcohol correlate well with concentrations in lung alveoli, thus the basis of the breathalyzer test used by law-enforcement officers. Alcohol is metabolized primarily in the liver. Most consumed alcohol is...

How is hyponatremia classified

Hyponatremia may occur in the presence of hypotonicity, normal tonicity, or hypertonicity thus it is important to measure serum osmolality to determine the cause of hyponatremia. Assessment of volume status is also important in determining the cause. An excess of total body water is more common than a loss of sodium in excess of water. Table 5-1 summarizes causes and treatment of hyponatremia. Congestive heart failure cirrhosis SIADH, Syndrome of inappropriate antidiuretic hormone.

Joy L Hawkins MD

Where is the epidural space Describe the relevant anatomy. The epidural space lies just outside the dural sac containing the spinal cord and cerebrospinal fluid CSF . As the epidural needle enters the midline of the back over the bony spinous processes, it passes through Beyond the epidural space lie the spinal meninges and CSF. The epidural space has its widest point 5 mm at L2. In addition to the traversing nerve roots, it contains fat, lymphatics, and an extensive venous plexus....

Describe the lithotomy position and its common complications

Common Positions For Anesthesia

The patient's hips and knees are flexed, and the patient's feet are placed in stirrups to gain ready access to the genitalia and perineum. The range of flexion may be modest low lithotomy or extreme high lithotomy . The feet may be suspended on vertical structures known as candy canes or in boots, or the knees may be supported with crutches. With elevation of the legs, pressure is taken off the lower back, and blood is translocated from the lower extremities to the central compartments....

Explain the gate theory of pain

In 1965 Melzack and Wall proposed that the substantia gelatinosa in the spinal cord was the primary gate in the transmission of noxious and nonnoxious stimulus to the central nervous system. The pain gate is opened by information coming from slow unmyelinated C fibers and closed by the impulses from faster myelinated fibers such as A-p. Since pain is transmitted by slow A-S and C fibers, they reason that, by activating faster fibers such as the ones that transmit proprioception, the gate will...