Ek 101 verbal 2nd edition pdf 2008 download

Do not guess, because that counts against you. You have 10 minutes. Always try to make the numbers as small as you can, which makes it easier to see the relationship with another number.

In the first place try to divide the smaller number of the pair into the larger one. For example, in Question 4, divided by 6, gives you , which makes a pair with answer d. To reduce numbers to a manageable size remember that any pair of numbers that are even can always be divided by 2.

If one or both of a pair is odd it cannot be divided by 2, so try 3, then 5, 7, and so on until your divisor is too large to go into either number. When you have a spare moment, simply take a number, say, any number from 1 to 15, and count up in multiples of that number.

Another good exercise to do in your head is to take a small number, such as 2, and keep doubling it. Potential in this area could point to many careers where the analysis of quantitative data is important. Such areas might be as diverse as marketing and science, because both involve the use of statistics. You have to see what is relevant in the information with which you are presented. When performance on this test is better than that on any other test it generally indicates that your level of academic attainment has not been fully expressed, even if you have already done well academically.

You are given a series of pictures, lines or diagrams. Your task is to see how they go together, then work out which will be the next figure in the series. You have to choose one from the four possible answers provided. Example Which comes next? The long bar, which slopes from right to left, is always added first. If you are timing yourself you have 6 minutes to do as much as you can.

Put the correct answer in the box. Which comes next? It is unlikely that any of the problems will actually be very complex. Always look for the simplest logical solution. You have to hold the image in your mind while working out the rest of the problem, and mentally constructing where the image is going to emerge. In Question 13 the white circle is moving up and down while the black circle is moving around the big circle. Those who do well on this visual test are often good at research and ordering information, for example, in social or historical research as well as other sciences connected with biology.

In one type of problem you are given an example of how two pictures relate to one another and you have to see how the next picture relates to one of the four possible answers provided. In the second type of problem you have to see how one of the objects is different from the others. Examples Example 1 This This is to is to this this as as this this is is to to a a b b c d d Answer Example 2: Which is the odd one out? In Example 2 the answer is b because it is the only one where one figure does not fit inside another and because both figures are the same size.

This is to to this this as as this is to to a a b c d d Answer 2. If you are unsure whether this is allowed, ask the test administrator.

If you are working from a book like this, or from a booklet, unless you are given permission you should not mark the booklet in any way. You are almost bound to lose out if you do not follow the instructions given, especially in regard to damaging property that is not yours.

If you are allowed to draw, or do calculations or whatever is necessary, do not worry what your rough work looks like: it is only your answer that counts. Although it is sometimes possible to say that each of the figures is odd, being different from the others, you must look for the easiest logical solution, not a complex one.

For example, in Question 4, a is the only diagram to have two shapes that also overlap, while b is the only square. Shape c is the only triangle, while d is the only shape that does not fill a space. This This is to this this as this this is to a b b c d Answer 8. This This is to is this this as as this this is to is to a b c c d d Answer This This is to to this this as as this this is to to a a b b c c d d Answer This isis to to this as as this is is to a b c c d d Answer This test is a good predictor of how well you can see how various things or ideas go together.

This type of visual aptitude is often associated with success in biological sciences and many areas of research. Decide the picture that comes next at the bottom of each line and select your answers from the chart on page The answer will always need to have two letters which reference the row and column on the chart at which the answer is found.

In the three examples number 1 has been done already to show you how. Examples 1 2 3? In Example 3 the shaded five-sided figure appears every other time. It will appear next in line. Expert tip Have plenty of scrap paper ready. Follow this rule whenever you take a test. In this particular test where it is necessary to remember more and more information, you will find it helpful to make a note of what you are doing as you work out the problem.

In the case of this test, you may find it more convenient to draw any figures that need to be remembered. You will need to keep looking back at the reference chart on page as you do the test.

Have scrap paper and a pencil in case you need it. Answer Expert tip One way to work out these problems is to break them down into parts and do each part separately.

For example, in Question 7, take the shape, which has a sequence, circle, circle, polygon, circle, circle, polygon, so that the next will be circle. Write it down or draw it on your scrap paper. Then consider the shades, which are alternately shaded then white, so the next will be shaded. You now have a shaded circle. From the chart this is EM or ME. Answer Expert tip Your working notes or drawings will not be judged.

In most tests you will have to hand in any rough notes. This is merely disposed of: it is not eval- uated because it is not a part of the test itself. It is your answer that counts, not any workings out that you used to get to your answer. CQ BP DL AM EO EK AN FQ AO BL EN BM AQ EL BN CL AK FP EM DM FL CK DK This test often reveals decision making and managerial potential, and people who do well display the ability to see through a problem, and how to deal with it in the most simple, direct way.

For these reasons, people with this type of talent are often regarded as natural leaders. Why such an abstract test is able to reveal talent in this way is not yet properly understood. We do this all the time in our daily lives, without giving it a thought, but psychologists have not yet discovered how a solid, three- dimensional shape is held in the mind, let alone what mental processes allow us to turn it around in our heads.

It is a vital skill anyway, and one that some people are better at than others, as with most skills, which is the reason it is tested. The shapes become increasingly rounded until precise defi- nition is almost lost. There are two types of problem. Look at the examples below to see how the test is done. Examples Example 1. If the figure below on the left was folded together it would make a box. Imagine the box is made of paper or card, so that you cannot see through it.

On this box, a line has been drawn across one of the sides. You have to say which of the alternatives would be made from the unfolded figure on the left. Example 2 take away leaves A. In both types of problem, remember that the answers might have been turned around or turned over, but still could be correct.

If you are timing yourself, you have 6 minutes. Answer B. Answer C. Answer D. Answer F. Answer G. Answer H. Answer Expert tip You can turn the test paper around or upside down if it enables you to see the problem more clearly. Answer J. Answer K. Answer L. Answer N. Answer O. Answer P. They are funda- mental to a range of careers in engineering and technology. All the blocks are the same size. Each block has six faces because the ends of the block also count as faces.

Blocks that connect only at the edges or at corners do not count. In the space provided, you have to write in the number of faces touched by each of the blocks. In the example below, the answer for block A has been given already to show you how. Complete the answers for the other blocks, B, C and D. Then read the explanation to make sure you understand what you have to do in this test.

Example A. If you are timing yourself you have 5 minutes to do as many as you can. Answer A. As there is no proper working out to do, apart from counting the number of sides, it wastes time to draw the figure yourself. The quickest way to do the test is simply to count as you go along.

Many people do not do as well as they could on this test because they spend too much time on checking. If you make a careful count as you proceed, checking will rarely be necessary, while a very occasional error is unlikely to count against you. Answers A. This is the type of test that has been used as one way of estab- lishing a talent for architecture and engineering, which require various operations of forming, molding and modelling.

You are shown a shape in the middle of the page. Below it are five other shapes. Each of these is numbered. You have to decide whether each of the alternatives is identical to the original shape. Each one of the shapes might be the original shape, but turned around and possibly also turned over. It must be the same height and thickness to qualify as a version of the original shape. The first example has been done for you. If you are timing yourself you have 10 minutes.

It is better to leave out an item you are unsure of. You will not be penalized for omitting items. It is the final score that is important. If you do well on this test you must have a talent for design visual- ization that has probably emerged already in some artistic way. This potential can be used in many areas of study and work. These range from art and design work itself, to almost any kind of problem where infor- mation has to be fitted together to create a final picture. This is why many people who work in web design, for example, have this talent.

What is also being measured is how well you can maintain your concentration. At the same time, you have to substitute symbols for numbers, thus making the task more complex. The test is in three parts, to enable you to see whether you are more proficient with words, numbers or pictures. Practice on all of the tests in this chapter can improve your performance.

You are given a list of names. Your task is to decide which one comes first in alphabetical order and which one comes last. Look at the example to see how you are to give your answer. Both letters must be marked correctly to score a point. Do the next example yourself. You must get both letters correct and also in the correct order to score a point.

Expert tip Remember not to guess; accuracy is what is being looked for and this may be more important than the overall total. Flag for inappropriate content. Download now. Save Save examkrackers verbal passages in mcat verbal re For Later.

Original Title: examkrackers verbal passages in mcat verbal reasoning. Related titles. Carousel Previous Carousel Next. Jump to Page. Search inside document. Versat Test 4 Versat Test 5. Versa Test 8. Veroat Test 9, Versa. TEST Veraat Test Test These appear just prior to Verbal Test 1. You are given 60 minutes for a full-length Verbal Reasoning test Take the three sample test passages frst, allotting yourself about 25 minutes.

Grade your test and check the explanations for both correct and incorrect answers at the back of the book. When you are ready to take your first full-length Verbal Test ensure that you will not be bothered for at least an hour. Treat these practice tests like the real thing It as not very practical or helpful to write your answers or considerations on a prece of notebook paper.

That way you are at least eliminating and narrowing choices that are not possible or are less likely. Using the process of elimination is, a very helpful technique on the MCAT The Computer Based Test allows the use of strikethrough and highlight functions right on the screen to help with narrowing down choices.

When you are done with your practice test, take a short break You've earned 1t. To find your raw score, count the number of questions that you answered correctly. Use the table at the back of the book fo translate your raw score into an MCAT scaled score How did you do? Tum to the Answers and Explanations section of the book and examine the explanations Check your schedule for when you will take your next prachce test.

Classteal actors often practice Shakespearean productions, which affects their 96 style Since the Elvzabethan stage was unamplitied and viewed from a distance, classical acting. On the basis of the passage, 1t 1s reasonable to conclude that A. Marlon Brando would not have done well in an Elizabethan stage productos.

Assume that Judy Dench was interviewed. If Ms. Dench remarked thar often, in her film career, she had refused. Children may often he, or say that they will do something while having no intention of actually carrying through with what they are saying. What question might this nformation reasonably suggest abont the author's explanation of acting styles?

Children can be good natural actors B. Did Stonsslavsks analyze children to come up with the bass for hs style? Uonly D. Hand Ill only 6. According to passage information, when compared to Elzabethan stage characters, characters in films would appear AL more realistic B. However, these items are not suitable for export to the sweltering dry heat of Africa and the antebellum South.

The reasons are again 60 historical The ue evolved from other, more archaic badges Of class und rank, whose symbolic ymplications persist. The author most likely beleves that one of the main purposes of clothng should be 10 provide the wearer wath A.

Amappropnate theory based upon the emerging dominance of the British business suit lines 18 that the best designed clothes are not necessanly the most comfortable. The amthor implies that the primary purpose of women's 2 fashion 1s: A. Yet this 1s sill noe the Mactnavellian ideal, he comments," by these methods fone may indeed gain power, but not glory his countless 4 atrocities.. We are not like that.

We know no one ever serzes power with the intention of relinquishing xt. Power 75 means; tis an end. Ins renown and his abulty as a strategist.

In contrast to the external style 1s the Method. Ibis pure conjecture 3. For stance, what af the roles. However, 11s nor clearly weakened by the question assumption Apparently, Ms.

Dench was considered a classically tramed actress lines D. Children may often hie or say that they wall do something while having no intenuon of actually carrying through with what they are saying What question might this snformation reasonably suggest about the author's explanation of acting styles? According to the passage, the best actress to realistically portray the character of the blind Helen Keller m a feleviston documentary would be one who has been tramed primarily in L.

The author most likely believes that one of the main purposes of clothing should be to provide the wearer wath A. Amappropnate theory based upon the emerging dommance of the Betish business suit lines 1s that A. This 15 not 1 Answer A plied by the author. See « confront traditional styles. The author? The quote 1m the question does not challenge this descnptuon No inference can be made regarding how long this government had been in power D.. If you are not certain of an answer, eliminate the alternatives that you know to be incorrect and then select an answer from the remaining alternatives.

Is tt nght under any exrcumstances to expenmment with animals? Do we have a moral obligation towards animals? Forexample, its wrong to torture smumals because it desensitzes us to human suffering and makes us more prone to using violence towards humans, Empathy as a differentiating principle 1s of little use because at 18 prumanly structural.

We cannot determine through empathy whether another creature, like another human, 1s expenencing pain Additionally, paun is value yudgment and the reaction to as not only relauve, but also culturally dependent. The author amples that an animal does not A. Questions have complete explanations for correct and incorrect answer choices. There are 12 tear-out answer grids in MCAT form in the back of the book. Statement of responsibility from cover.

This volume includes fourteen minute EK verbal passages - too easy? Student Doctor Network. Clin Exp Rheumatol. CT angiography in trauma.

Diagnostic imaging in Takayasu arteritis. Curr Opin Rheumatol. North Am. Wojtowycz M. Handbook of Interventional Radiology and Angiography.

Mosby; Infected mycotic aneurysms: spectrum of imaging appearances and management. The development of modern angiography was enabled by one approach to the procedure. Most important, personal review simple technique: the percutaneous introduction of devices into of noninvasive vascular studies, prior angiograms, and correla- a blood vessel over a wire guide Fig. Described by Sven tive imaging is essential before embarking upon any invasive Ivan Seldinger in , this elegant innovation now known by procedure.

Introduce and identify yourself before examining ment. Virtually all vascular and many nonvascular invasive proce- the patient. A general assessment of risk for the procedure and sedation should be made.

As an position necessary for the procedure should be considered before interventional radiologist, you should not only be skilled with going forward. The strength of the pulses and the presence of peripheral Ideally, you will have seen the patient previously in consulta- aneurysm as suggested by a broad, prominent pulse should be tion and selected which procedure to perform.

The evaluation recorded using a consistent system. Cellulitis, fresh surgical inci- is the same in clinic or at the bedside, and begins with a review sions, a large abdominal pannus, or a dense scar over the vessel of the clinical issue.

Do you understand the diagnostic ques- all influence selection of an access site. Pulses distal to the antici- tions and the information needed? Do you understand the dif- pated access site must be evaluated and recorded. This baseline ferent therapeutic options? A brief, directed history should be information is useful if an occlusive complication occurs or to obtained. In particular, the symptoms or signs that precipitated determine success of a revascularization procedure.

The physical the consultation are important, as this knowledge may impact examination should include both sides of the patient in case an the course of the subsequent examination and interpretation of alternate or additional access is required during the procedure.

Other essential areas to cover in the history include When an upper extremity approach is anticipated, blood pres- prior surgical procedures especially vascular ; evidence of ath- sures in both arms must be obtained. Classification exposure to iodinated contrast agents. Operative notes and reports from previous angio- prognostic implications, and allow assessment of outcomes of grams provide valuable information that may alter the entire interventions see Tables and Seldingertechnique An intravenous infusion should be established before arriving in the angiographic suite.

Most hospitals have guidelines for oral intake before invasive procedures; however, these are generally not designed for patients about to receive large doses of nephro- toxic contrast. There are no laboratory studies that are absolutely mandatory A before conducting an angiogram.

However, because the procedure involves making a hole in a blood vessel and administering neph- rotoxic contrast material, reasonable laboratory tests in patients at risk include coagulation studies international normalized ratio [INR] or prothrombin time PT , activated partial thromboplastin time [aPTT] , platelet count, and serum creatinine Cr.

Routine laboratory studies can be safely omitted in young patients without B known coagulation disorders or renal dysfunction. A prolonged PT or INR is usually the result of warfarin ther- apy, liver disease, or poor nutritional status. Femoral arterial access is safe when the INR is 1. Coagulation studies should be normal for axillary, high brachial, or translumbar aortic access.

Vitamin K phytonadione administration for reversal of C coagulopathy caused by warfarin, liver disease, or vitamin K defi- ciency is effective but can require a day or more to work.

FFP contains normal quantities of all coagulation factors. The effect of FFP is fast but volume related; mL per kg is usually required to normalize a coagulopathic patient each bag contains mL. The half-life of some of the coagulation factors in D FFP is short e. Seldinger technique. A, Percutaneous puncture of a blood in severely coagulopathic patients. B, Introduction of an atraumatic guidewire A prolonged aPTT is usually due to administration of unfrac- through the needle into the blood vessel lumen.

C, Needle is removed tionated heparin low-molecular-weight heparin does not alter the while guidewire remains in place. Compression over the puncture secures the guidewire and prevents bleeding. D, Angiographic catheter is advanced aPTT , which can be turned off when the patient arrives in the into vessel over the guidewire. From Kadir S. Diagnostic Angiography. Because the half-life of heparin is roughly 60 minutes, most patients will be sufficiently reversed to allow manual compression by the end of the procedure.

Even in the presence of normal coagulation studies, thrombocytopenia carries a high risk of Class Definition bleeding complications. Most angiographic procedures can be safely performed in patients 5 A moribund patient who is not expected to survive taking platelet-inhibiting agents such as aspirin or clopidogrel. From www. In the presence of an abnormal serum Cr, the risk of renal failure after the procedure should be weighed against the benefits of the examination.

Prophylactic measures should be followed to maxi- Patients should be well hydrated prior to the procedure. Outpa- mize renal protection see Contrast Agents. During the procedure, tients who will have conscious sedation should not be instructed dilution of contrast in a ratio of or even NS:contrast , limited to fast after midnight, but rather encouraged to drink clear liquids use of hand injections, digital capture of fluoroscopic images, and no solid food until 2 hours before their scheduled appointment.

Patients for whom useful techniques to minimize contrast use. Typical access needles. A, From left: gauge Seldinger needle with hollow, sharp central stylet that extends beyond the blunt tip of the needle; stylet; Seldinger needle with stylet removed; gauge sharp hollow one-wall needle; gauge microaccess needle.

B, Microaccess system. From left: gauge needle; 0. Consistent use of masks, face shields or other protec- Access Needles small mobile cowpressed tive eyewear, sterile gloves, and impermeable gowns should be routine. Closed flush and contrast systems minimize the risk of All percutaneous angiographic procedures begin with an entry splatter. All materials used during the case should be discarded in needle. There is great variety in vascular access needles, but all receptacles designed for biological waste.

Needles, scalpels, or any other sharp device used during a Needles with a central sharp stylet that obturate the lumen have case should be carefully stored on the work surface in a red a blunted, atraumatic tip when the stylet is removed. The sty- sharps container or removed immediately after use.

Recapping let allows the needle to puncture the vessel, but once removed is not advised. Verbal communication when handling sharps is theoretically reduces the risk of trauma. The stylet may be solid essential. The best sharps containers contain a foam block in or hollow. In the latter case, blood can be visualized on the sty- which the point of the sharp can be embedded. At the end let hub once the vessel lumen is entered.

The stylet must be of the case, it is the responsibility of the physician to dispose removed in order to insert the guidewire. Needles with stylets of the sharps in the appropriate receptacle. Puncture wounds are generally used only for arterial punctures. Needles without from contaminated sharps are not only painful, but also poten- stylets have very sharp beveled tips, a quality that is useful when tially life-altering.

If an accidental splash, puncture, or other attempting to puncture small, mobile, or low-pressure vessels. This style of needle is essential. Radiation exposure to the patient and the staff should be The most common sizes for vascular access needles are to kept to minimum. Use fluoroscopy only as needed. The lower the hold, the ability to store and review fluoro loops, and imaging gauge number, the larger the diameter of the needle will be.

The with pulse-mode fluoro Prolonged fluoros- The gauge needles are often packaged as part of a microac- copy at high magnification with the x-ray tube in one position cess system that includes a small guidewire and coaxial dilators can cause cutaneous radiation burns to the patient.

Cumulative that convert the puncture to a standard-sized guidewire. These exposure to physicians from scatter, especially when standing at needles are designed to be highly visible under ultrasound to the side of the patient during imaging, can be substantial. Wrap- facilitate image-guided access. Microaccess techniques can be around lead, thyroid shields, and leaded glasses should be worn.

Leaded table drapes, careful coning of the beam, minimizing the air-gap between the image-intensifier and the patient, and Guidewires 18ZIG Ng 5 inch use of boom-mounted x-ray shields are all means to decrease Guidewires are available innano access physician exposure to scatter. In general, the guidewire thickness always save time, this is a bad habit.

Radiation badges should be worn referred to in hundredths of an inch; e. Guidewires that are too big will jam back problems over time. Careful design of angiographic suites inside the catheter. However, if a guidewire is much smaller than with attention to positioning of controls and monitors can reduce the hole at the tip of the catheter or device there will be an abrupt twisting and bending.

In the future, robotically assisted or per- transition or step-off that creates a gap that can trap subcutaneous formed procedures will further decrease operator risk. Common guidewires. From left: Straight 0. Basic construction of common guidewires. Catheter and guidewire mismatch. The catheter is tapered structed of an outer coiled spring wrap, a central stiffening mandril to 0.

The inner mandril slides back and forth, and can be removed entirely, using the handle at the back end of the guidewire arrow. This changes the stiffness of the wire tip. The remainder of the guidewire is a plain mandril.

Reproduced from Cook coiled spring Fig. The outer wire is welded to the core at the Group Incorporated, Bloomington, Ind. The purpose of the coiled wrap is to decrease the area of contact between the surface of the guidewire and the tissues. Between the inner core wire and the outer wrap TABLE Guidewire Stiffness is a fine safety wire that runs along the length of the guidewire Guidewire Stiffness and is welded to the outer wrap at both ends.

The safety wire prevents the wrap from unwinding. This is where the term safety Movable core 0 when core removed guidewire originates. The thickness and composition of the inner core determines the degree of guidewire stiffness Table Standard 0. This is a common construction for small-diameter guidewires, or extra rigid large- diameter guidewires.

The length degree of safety in diseased vessels. As the curved guidewire is and rate of transition of the taper defines the characteristics of advanced, the round presenting part deflects away from plaque, the tip. Bentson guidewires, or movable core guidewires with whereas the tip of a straight guidewire could burrow under it. A the core retracted, have the softest tips. During diagnostic pro- curve can be added to a straight guidewire by gently drawing the cedures, the soft end of the guidewire goes inside the patient.

In some instances, adding a curve to useful recanalization tool. Tip deflecting guidewire. This wire has a stiff tip that is used to direct a catheter.

A, The guidewire and the preattached handle. B, Deflection of the guidewire tip. The deflection is per- formed inside the catheter lumen. The catheter is then advanced off of the guide- A B wire; the guidewire is never advanced beyond the tip of the catheter. Tip-deflecting guidewires allow variation in the radius of the curve while in the patient, but these guide- wires have stiff tips and should never be advanced beyond the end of the catheter Fig.

Specialty guidewires, such as wires coated with slippery hydro- philic substances, highly torqueable guidewires, kink-resistant nitinol-based wires, and microwires are widely available. These guidewires are the difference between routine success and fail- ure in the more challenging cases. Hydro- philic-coated guidewires are especially useful, because they can easily reach previously inaccessible places.

Vascular dilators. The latter is useful when more gradual dilatation material see Fig. These guidewires should not be inserted is required. Do not dilate an access the guidewire is withdrawn. When this happens, it is dif- with manual compression is anticipated; when the diameter of the ficult to advance a catheter over the guidewire. Furthermore, the hole in the wall approaches the diameter of the artery, the punc- entire guidewire may be pulled inadvertently out of the patient ture becomes a partial transection.

To stabilize a hydrophilic guidewire during a catheter exchange, grip the wire with wet gauze. This allows a secure hold without drying out the guidewire.

Catheters The length of most guidewires used in routine angiography is Angiographic catheters are made of plastic polyurethane, poly- cm. When more guidewire is needed inside the body, or ethylene, Teflon, or nylon. Catheters for aortography are thick walled to handle guidewire outside the body is unwieldy and easily contaminated.

Vessel dilators are short tapered catheters usually made of a stiffer Conversely, selective catheters are thinner walled for lower vol- plastic than diagnostic angiographic catheters Fig.

The sole ume injections, shaped to seek branches off the main vessel, and purpose of a dilator is to spread the soft tissues and the wall of the tapered at the tip to advance smoothly into the branch vessel, with blood vessel to make passage of a catheter or device easier. By a single end hole to direct contrast in a specific direction. Precise inserting sequentially larger dilators over a guidewire, a percutane- control of the tip of the selective catheter is a top priority.

Selec- ous access with a gauge needle can be increased to almost any tive catheters therefore usually have fine metal or plastic strands size. The first dilator size after Many different units and systems are used to describe a single puncture with an gauge access needle is usually 5-French. Common catheter shapes. Pigtail flush catheter left with multiple side holes. Selective catheter right with a single end hole. Drawing illustrating the fine wire braid in the shaft of a selective catheter.

The dark color at the end of the catheter is radiopaque, facilitating visualization of the catheter. Steaming a catheter. The length of the catheter is in cen- timeters usually between 65 and cm. There are so many different catheters that no one department can or need stock them all.

The shape of some catheters may be mod- ified by bending into the desired configuration while heating in steam and then rapidly dunking in cool sterile water Fig. Complex catheter shapes must be reformed inside the body after insertion over a guidewire. The catheter will resume its 3 original configuration if there is sufficient space within the ves- sel lumen and memory in the catheter material.

Branch technique for reforming a Simmons catheter. Aortic shapes cannot reform spontaneously, in particular the larger bifurcation is shown in this illustration. There are a number of proximal to the origin of the branch but still in the catheter. One may ways to reform these catheters Figs.

A recurved also remove the guidewire and reinsert the stiff end to the same point. Aortic spin technique for reforming a Simmons catheter works best for Simmons 1. Note the wire is withdrawn below the curved portion of the catheter. Ascending aorta technique for reforming a Simmons cath- eter.

The 2 catheter is advanced over the guidewire. Cope string technique, which easily reforms any recurved catheter. The catheter is then loaded onto a floppy-tipped guidewire dashed line and advanced arrow into the patient. Suture material is pulled gently black arrow as slight forward force applied to catheter gray arrow. Suture material can then gently be pulled out black arrow. Straight and pigtail catheters are generally used for nonselec- tive injections. Straight catheters should only be advanced over a guidewire; pigtail catheters can be safely advanced in nor- mal vessels once the pigtail has reformed.

Before removal of a pigtail catheter from the body, the tip is usually straightened with a guidewire. Straight catheters can be removed without a 3 guidewire. Deflecting wire technique unsafe in small or diseased aor- Selective catheters are chosen based upon the anatomy of tas. The technique for selecting deflected, curving the catheter as well.

The Waltman loop, which can be formed in any major aortic branch vessel with braided selective catheters. A, An angled catheter positioned over the aor- tic bifurcation. Note the stiff end of the guidewire at the catheter apex arrow. B, The catheter is advanced and twisted, forming the loop.

C, Looped catheter has been used to select the ipsilateral internal iliac artery arrow. Aggressive probing with the catheter or guidewire is placed securely in a proximal position in the guidewire, or advancing the catheter into the branch without blood vessel. The microcatheter is then advanced in conjunc- leading with at least cm of soft guidewire, can result in arte- tion with a specially designed 0. The Waltman loop is particularly guidewire through the standard catheter lumen.

Once a super- useful in the pelvis for selection of branches of the internal iliac selective position has been achieved with the microcatheter, a artery on the same side as the arterial puncture. The resistance to flow coaxially within the lumen of a standard angiographic catheter in the small lumen prevents the use of most microcatheters for are termed microcatheters Fig.

These soft, flexible cath- routine angiography. High-flow microcatheters can accept up eters are 2- to 3-French in diameter, with 0. They are designed to reach beyond standard Contrast and flush solutions are most easily injected through catheters into small or tortuous vessels. The ability to reli- these catheters with 3-mL or smaller high-pressure Luer-lock ably select these vessels without creating spasm, dissection, or syringes.

To use a microcatheter, a stan- stabilizing standard catheters and devices. These nontapered dard angiographic catheter that accepts a 0. How to use a Simmons catheter. Choosing a selective catheter shape. A, Angled catheter gentle traction results in deeper placement of catheter tip. To deselect the when angle of axis of branch vessel from aortic axis is low.

B, Curved branch, push the catheter back into the aorta reverse steps To catheter e. C, Recurved catheter e. Be aware that guiding catheter size in French refers to the outer, not the inner diameter.

Sheaths Most vascular interventions and many diagnostic procedures are performed through vascular access sheaths. These devices are plas- tic tubes of varying thickness and construction that are open at one end and capped with a hemostatic valve at the other Fig.

The open end is not tapered, although the edges are carefully bev- eled to create a smooth transition to the tapered dilator that is used 1 2 to introduce the sheath over a guidewire.

The valve end usually has a short, flexible, and clear side arm that can be connected to a constant flush to prevent thrombus from forming in the sheath or an arterial pressure monitor. The valve may be a split membrane or rotating hub. The purpose of the sheath is to simplify multiple catheter exchanges through a single puncture site.

When not using a sheath, it is unwise to downsize catheters during a procedure owing to the risk of bleeding around the smaller diameter catheter. Perhaps more important, devices that are irregular in contour or even nontapered can be introduced through a sheath without dam- aging the device or traumatizing the access vessel.

Long sheaths can be used to straighten a tortuous access artery or negotiate a tortuous aorta. By convention, sheaths are described by the maxi- mum size in French of the device that will fit through the sheath. How to use a cobra catheter. Contrast is the requirements of the procedure. Used been advanced into branch. The guidewire is held firmly and the catheter frequently when inserting venous access devices, this sheath is advanced arrow.

Two wings or tabs at the hub are pulled apart to split the sheath. Some peel-away sheaths have hemostatic valves, although these are usually not as robust or that accepts standard sized catheters and devices Fig. Guiding catheters with tips can be reshaped within the patient The sheath is introduced in standard fashion over a guidewire with a using controls at the back end of the catheter.

There are many tapered plastic dilator. Once in position, the dilator is removed. The circumstances in which standard catheters are difficult to posi- only way to achieve hemostasis with a nonvalved sheath is to block tion selectively, such as in the case of a renal artery that arises the open end with a finger or to clamp the sheath. After inserting the from a tortuous or aneurysmal abdominal aorta. In this situa- device or catheter through the sheath, the plastic wings are pulled tion, a larger outer catheter that can guide the standard cath- in opposite directions parallel to the skin.

Guiding catheters are usually shorter from the catheter without having to slide it off the back end. Use of a microcatheter. A, Typical microcatheter that tapers from 3-French proximally to 2. Note the radiopaque marker at the tip. B, Extremely tortuous splenic artery in a patient with hypersplenism. C, Microcatheter has been advanced over a 0. Typical hemostatic sheath. French size of sheaths refers to the inner diameter.

Stopcocks are plastic devices that allow one or more syringes to be connected to a catheter, and by turning a handle or sliding a switch, allow or block flow Fig. Rotating hub adaptors have one or more potential entry points for a guidewire or catheter.

Hemostasis is achieved by tightening the hub by rotating it clockwise. Metal stopcocks are needed when handling oil-based contrast agents because many plastics become brittle and disintegrate when exposed to the oil. Two examples of nontapered large-diameter guide cathe- ography as the Seldinger technique. The ideal contrast agent has ters, which can accommodate standard 5-French catheters. French size of excellent radiopacity, mixes well with blood, is easy to use, and guide catheters refers to the outer diameter.

Iodinated contrast agents based on benzene rings with three bound iodine atoms, termed triiodin- ated are, as of yet, closest to ideal. Adverse reactions may be immediate within seconds to minutes of injection or delayed hours to days.

The two major adverse reactions to iodinated contrast agents are anaphylaxis and renal failure. True anaphylaxis occurs shortly after contrast injection and is distinguished from a vasovagal response by tachycardia and respiratory distress Table