With various levels of difficulty 5 mg propecia sale hair loss 5 months after giving birth, a continuum of inanimate exercises can guide surgeons of different abilities through their initial learning curves buy propecia 5mg visa hair loss with pcos. Inanimate exercises for learning the fundamentals of laparoscopic surgery can be expanded to effectively target robot-specific skills . In order to be useful training tools, inanimate exercises must challenge both specific technical skills of using a robotic surgical system and have validated metrics so that surgeons can accurately track their performance . It is certain that the advent of excellent surgical simulators and structured inanimate exercises has provided tools for novice surgeons to acquire console skills in a safe and structured environment. This will enhance their operating performance and reduce aspects of the learning curve such as operating time; however, the lack of availability of in vivo training opportunities greatly limits the applicability of this method of surgical training . Dual Console The introduction of the da Vinci Si Surgical System has given surgeons a second robotic console, facilitating collaboration between the proctor and trainee. The mentoring console has two collaborative modes: (1) The swap mode allows the mentor and trainee to operate simultaneously and actively swap control of the robotic arms. Live Surgery and Proctoring Live case observation remains an important component of a robotic training program  and allows the trainee to become familiar with the steps of a specific robotic procedure. Proctoring is defined as direct supervision by an expert during the initial phase of training and the learning curve . It provides a safe environment during the introduction of a new technique and prevents surgeons from performing procedures before they have mastered the technique. The reality is that simulators, dual consoles, and robotic courses should play an important role in bridging the gap between early surgical skills and effective performance using the robot in a clinical setting without subjecting patients to unnecessary risk. It is also important to have tools that provide an objective means by which to evaluate a trainee’s performance in anticipation of their ultimate graduation . Participants who acquire skills faster regain robotic skills faster after a training hiatus, but, on retraining, all participants can regain equivalent competence. One institution has incorporated a graduated program of resident and fellow console involvement based on level of training. They found this approach did not significantly hinder operating room efficiency . In one study, robotic surgical skills degraded significantly within 4 weeks of inactivity in newly trained surgeons . The University of Toronto in a pilot study assessing robotic skill training concluded that the implementation of a multidisciplinary, simulation-based robotic surgery basic skills training curriculum revealed significantly improved basic robotic skills among novice trainees, regardless of specialty or level of training. The competency-based training was associated with significantly better acquisition of basic robotic skills. A recent study assessing the learning curves associated with a robot-assisted laparoscopic colorectal surgery revealed that it consisted of three distinct phases . The first phase or the initial phase occurred over the first 15 cases, during this phase the operating time decreased. The second phase or plateau phase occurred over the next 10 cases; during this phase, the operator becomes more competent with the robotic technology. The learning curve associated with laparoscopic sacrocolpopexy has been shown to be linear in nature with the turning point between 18 and 24 cases . The robotic approach maintains the benefits of laparoscopy while reducing the technical difficulties [21,23,66]. Knot tying has been shown to be a technical challenge for laparoscopic sacrocolpopexy due to the limited dexterity of the instruments . These challenges are not present in the robot-assisted surgery where studies have shown that due to the instrument grip strength sutures can be tightened effectively . In New York, a study comparing the learning curves for robot versus laparoscopic surgical skills highlighted that with regard to suturing and dexterity skills, the robot allowed for quicker performance than laparoscopy . First, have a designated theater team, with no introduction of new members until 20 cases have been performed. Second, patient positioning is of paramount importance and should be standardized for all cases, and finally, familiarization with the instruments sets is required before any deviation is considered . A recent survey of urologists on intraoperative robot malfunction found that breakdown intraoperatively is uncommon; however, it does occur, highlighting the need to counsel patients and to have a contingency plan. Furthermore, they recommend conventional laparoscopic suturing should be maintained as a requirement on the curriculum, thus allowing the surgery to continue using minimally invasive approach . A report of technical challenges faced by surgeons performing robot-assisted gynecological oncological procedures showed 8% were associated with problems with robotic technology. Of this 8% of cases, 18% involved malfunction of robotic arms, 18% involved light or camera cords, and the remainder included a variety of problems, including malfunction of Maryland bipolar instrument (9%). An estimated average of 25 minutes was added to each case in order to solve the robot-related technological problems. It is noteworthy that the robotic surgeon solved all these problems with the assistance of robotic surgery staff. They conclude that all surgeons performing robotic surgery must become familiar with troubleshooting robotic technology and associated equipment. Instrument failure accounted for 50% (9/18) of cases, 22% (4/18) occurred due to robotic arm failures, 16% (3/18) derived from console errors, the remaining 12% (2/18) failure occurred in the optic unit. Of note, the failure rate decreased with increased operator and team experience . They advocated that surgeons and their team should be specifically trained to troubleshoot for these issues . Neurological Injuries Patient positioning is of great importance to minimize the potential adversarial outcomes associated with long operative times. In a single unit study, nerve injury associated with positioning during 1530 urological robotic surgery had an incidence of 6. The injury rate was significantly affected by operative time and American Society of Anesthesiologists group. Therefore, patients undergoing long surgeries should be counseled regard the risk of nerve injury especially if they have multiple comorbidities . General Safety Checklists have been used as an intervention to prevent these failures by promoting a team-working culture, standardizing practice, allowing the detection of potential errors, and improving patient safety as a whole. It is a step-by-step process that involves the multidisciplinary team in identifying potential causes of error within a system through the use of flow diagrams, hazards scoring, and decision tree analysis. Potential errors are prioritized according to severity, frequency/probability, criticality, detectability, and existing control measures. The final process includes taking steps to implement solutions, minimize errors, and avoid adverse events . A unit-specific robot-specific checklist was developed with the aim of allowing the detection of potential errors and improving patient safety as a whole. Specific improvements associated with robot-assisted surgery include better visualization through the use of three-dimensional magnification, availability of tools with 7 degrees of freedom that mimic hand movements along with improved ergonomics, and more intuitive hand–eye coordination when controlling surgical instruments [79–81]. However, this has been achieved at the cost of haptic and tactile feedback, as a result of the instruments not being directly manipulated by the surgeon . It is yet to be seen whether tactile feedback can be achieved through increased sophistication of the computer software. There is limited primary data available in regard to the effect of using the robotic device on surgeon morbidity and discomfort.
Characterization of double potentials in human atrial flutter: studies during transient entrainment order propecia no prescription hair loss estrogen. Entrainment and interruption of atrial flutter with atrial pacing: studies in man following open heart surgery order propecia 5mg without a prescription hair loss labs. Self-initiated conversion of paroxysmal atrial flutter utilizing a radio- frequency pacemaker. Worldwide clinical experience with a new dual-chamber implantable cardioverter defibrillator system. Acceleration of typical atrial flutter due to double-wave reentry induced by programmed electrical stimulation. Electrophysiologic properties and response to pharmacologic agents of fibers from diseased human atria. The electrophysiological effects of intramuscular guinidine on the atrioventricular conducting system in man. Management of cardiac arrhythmias: pharmacologic, electrical and surgical techniques. Effect of procainamide and N-acetylprocainamide on atrial flutter: studies in vivo and in vitro. Amiodarone: correlation of electrophysiologic effects with control of atrial arrhythmias. Effects of selective vagal and stellate ganglion stimulation of atrial refractoriness. Flutter and fibrillation in experimental models: what has been learned that can be applied to humans? Sodium-calcium exchange initiated by the Ca2+ transient: an arrhythmia trigger within pulmonary veins. Abnormal vasovagal reaction, autonomic function, and heart rate variability in patients with paroxysmal atrial fibrillation. Coexistence of beta-1 and beta-2 adrenergic receptors in the human heart: effects of treatment with receptor antagonists or calcium entry blockers. Role of pectinate muscle bundles in the generation and maintenance of intra-atrial reentry: potential implications for the mechanism of conversion between atrial fibrillation and atrial flutter. Simultaneous epicardial and endocardial activation sequence mapping in the isolated canine right atrium. Mapping the conversion of atrial flutter to atrial fibrillation and atrial fibrillation to atrial flutter. Left-to-right gradient of atrial frequencies during acute atrial fibrillation in the isolated sheep heart. Stable microreentrant sources as a mechanism of atrial fibrillation in the isolated sheep heart. Electropathological substrate of long-standing persistent atrial fibrillation in patients with structural heart disease: longitudinal dissociation. Intraoperative electrophysiologic mapping and description of the electrophysiologic basis of atrial flutter and atrial fibrillation. Lack of evidence of electrical remodeling in patients with chronic atrial fibrillation. High-density activation mapping of fractionated electrograms in the atria of patients with paroxysmal atrial fibrillation. Epicardial mapping of chronic atrial fibrillation in patients: preliminary observations. Sites of focal atrial activity characterized by endocardial mapping during atrial fibrillation. Epicardial wave mapping in human long-lasting persistent atrial fibrillation: transient rotational circuits, complex wavefronts, and disorganized activity. Electropathological substrate of longstanding persistent atrial fibrillation in patients with structural heart disease: epicardial breakthrough. Time course and mechanisms of endo-epicardial electrical dissociation during atrial fibrillation in the goat. Classifying fractionated electrograms in human atrial fibrillation using monophasic action potentials and activation mapping: evidence for localized drivers, rate acceleration, and nonlocal signal etiologies. Activation of inward rectifier potassium channels accelerates atrial fibrillation in humans: evidence for a reentrant mechanism. Presence of left-to-right atrial frequency gradient in paroxysmal but not persistent atrial fibrillation in humans. Effect of pulmonary vein isolation on the left-to-right atrial dominant frequency gradient in human atrial fibrillation. Organized activation during atrial fibrillation in man: endocardial and electrocardiographic manifestations. Spectral analysis identifies sites of high-frequency activity maintaining atrial fibrillation in humans. Regional entrainment of atrial fibrillation studied by high- resolution mapping in open-chest dogs. Effects of high-frequency atrial pacing in atypical atrial flutter and atrial fibrillation. Chapter 10 Preexcitation Syndromes Preexcitation exists when, in relation to atrial events, all or some part of the ventricular muscle is activated by the atrial impulse sooner than would be expected if the impulse reached the ventricles only by way of the normal 1 atrioventricular (A-V) conduction system. The clinical significance of the preexcitation syndromes relates primarily to the high frequency of associated arrhythmias and to the various bizarre and often misleading associated electrocardiographic patterns. Understanding the pathophysiologic basis for arrhythmias in these disorders provides much of our knowledge concerning the mechanism of reentrant arrhythmias. The preexcitation syndromes previously were classified on the basis of proposed anatomic connections described by the eponyms Kent fibers, James fibers, and Mahaim fibers. The major objection to this classification was that it was imprecise and did not allow sufficient flexibility in explaining accumulated electrophysiologic and pathologic observations. As a consequence, many of these eponyms were inappropriately applied to various forms of preexcitation. Consequently, the European Study Group for Preexcitation devised a new classification of 2 the preexcitation syndromes, based on their proposed anatomic connections. These connections are (a) A-V 3 4 5 6 7 bypass tracts forming direct connections between the atria and ventricles, , , , , (b) nodoventricular fibers 4 8 9 10 connecting the A-V node to the ventricular myocardium, , , , (c) fasciculoventricular connections from the His– 11 Purkinje system to the ventricular myocardium, and (d) A-V nodal bypass tracts, direct communications from the 3 12 9 atrium to the His bundle, , or from the atrium to the lower A-V node via a specialized internodal tract, or via 13 14 specialized intranodal tracts with rapid conduction. Of note is that many of the fibers actually described by 2 4 10 Mahaim have been demonstrated to exist anatomically in the absence of electrophysiologic function. Because these pathways appear to represent developmental abnormalities, it is not surprising that multiple types of accessory pathways may exist in any individual patient. Atrioventricular Bypass Tracts The A-V bypass tract is the most frequently encountered type of preexcitation, and it is the only type for which a reproducible correlation has been demonstrated between electrophysiologic function and anatomic structure. The length of the P-R interval and the degree of preexcitation (which may be variable) depend on several factors: (a) A-V nodal and His–Purkinje conduction time; (b) conduction time of the sinus impulse to the atrial insertion of the bypass tract, which in turn depends on the distance between the bypass tract and the sinus node as well as on intra-atrial conduction and refractoriness; and (c) conduction time through the bypass tract, which is a function of its structure (length and thickness), the quality of input to the bypass tract, and the spatial–geometric arrangement between the atrium and ventricles, which determines the quality of the 21 24 electrical input and output of the bypass tract.
These and other observations concerning mechanism are discussed in detail later in this chapter order propecia master card hair loss cure germany. Over the past four decades generic propecia 5 mg with visa hair loss in men 3 button, electrophysiologic studies have been responsible for a greater understanding of ventricular arrhythmias. This has led to major advances in their pharmacologic and nonpharmacologic therapy. It is imperative that clinicians and clinical investigators recognize that the study of ventricular arrhythmias is still evolving. The role of electrophysiologic studies in evaluating nonsustained and/or polymorphic arrhythmias associated with metabolic disorders, drug toxicity, cardiomyopathy, and so on is not yet established. A discussion of our current level of understanding of this issue is included and detailed later. Definitions of Ventricular Tachycardias The definitions employed by electrophysiology laboratories are arbitrary but provide a useful framework for both the clinician and the electrophysiologist to distinguish “pathologic” responses from “normal” expected 1 2 3 responses. This is a fairly common mechanism of sudden cardiac 6 7 8 death recorded by Holter monitor. Duration Most laboratories consider a tachycardia sustained if it lasts ≥30 seconds. Repetitive polymorphic responses are also very common (up to 50%), particularly when multiple (≥3) extrastimuli are used with extremely short coupling intervals (<180 msec). The clinical significance of induced nonsustained polymorphic tachycardia is questionable and requires further evaluation to determine its relevance (to be discussed in subsequent paragraphs). They reported good sensitivity and specificity, but I have not found it significantly better than V1–2 criteria. Furthermore, A-V dissociation can be seen with supraventricular rhythms, fusion complexes can result from two ventricular ectopic foci, and morphologic and/or axis characteristics established for patients with normal P. In the absence of pre-excitation a supraventricular impulse must pass through the His bundle and the specialized ventricular conducting system before initiating depolarization of the ventricles. This may result because no engagement of the His–Purkinje system by the ventricular impulse occurs (probably uncommon), or because retrograde His bundle activation occurs during ventricular activation and is obscured by the large ventricular deflection in the His bundle recording. His deflections can usually be observed if attention is given to catheter position. One may identify His bundle activity before ventricular activation (in this instance, the H-V interval is shorter than normal; e. If His bundle deflections are not seen, one must differentiate the absence of retrograde activation of the His– Purkinje P. This can be fortuitously observed if a sinus impulse conducts antegradely to the His bundle producing a clear His deflection. In these instances, linking of the His bundle potential to atrial activation proves that they are due to antegrade depolarization and are unrelated to the tachycardia. Retrograde block in the A-V node is present because atrial activation is dissociated from the tachycardia. It is often difficult to determine whether the recorded His deflection is antegrade or retrograde—or for that matter whether an apparent His bundle deflection is really a right bundle branch potential. Two techniques that may be used to clarify the situation are (a) recording right and left bundle branch potentials to demonstrate that their activation begins before His bundle activation and (b) His bundle pacing producing a longer H-V interval than the one noted during the tachycardia. Both of these are extremely difficult to do but can help define the mechanism of His bundle activation and the tachycardia origin. The simplest methods for verifying proper catheter position include the following: (a) the immediate appearance of His bundle deflections on termination of the tachycardia, or conversely, disappearance of the His bundle deflection on initiation of the tachycardia, without catheter manipulation; (b) spontaneously occurring or induced supraventricular capture of the His–Purkinje system (with or without ventricular capture) during the tachycardia with the sudden appearance of His bundle deflections; and (c) in the presence of supraventricular capture, H-V intervals comparable to those during sinus rhythm (Figs. We have found that the use of more closely spaced bipolar electrodes (l to 5 mm apart) facilitate identification of His bundle activity when it occurs within the ventricular electrogram. The second atrial impulse (A) conducts through the His bundle but fails to alter the tachycardia. The first and third sinus complexes block in the A-V node due to retrograde concealment. Two complexes later, another supraventricular fusion is observed, again without influencing the tachycardia. This demonstrates lack of requirement of the His bundle for perpetuation of the tachycardia. If His deflections are not spontaneously observed during the tachycardia, because of either poor position or obscuration of the His deflection by the ventricular electrogram, rapid atrial pacing can be used to clarify the issue in some cases. Thus, knowledge of A-V conduction during sinus rhythm may be necessary to define what is a “normal” H-V interval during the tachycardia. Some investigators , suggest that the site of origin of such a tachycardia is within the His–Purkinje system. As stated earlier, pre-excited tachycardia using either an A-V or nodoventricular bypass tract must be excluded (see Chapter 10). It is not rare for a tachycardia to have a V-H interval less than the antegrade H-V interval (Fig. Retrograde conduction time over the His–Purkinje system is actually much greater than the “V-H” observed during the tachycardia. Depending on the relative conduction time up the His–Purkinje system and through slowly conducting P. Atrial pacing is begun (arrow) at a cycle length of 480 msec, which is gradually reduced to 400 msec. As the atrial-paced cycle length decreases, a greater degree of ventricular activation is produced via the normal conducting system. The His deflection typically occurs before the right bundle deflection with an H-V interval approximating the H-V interval during sinus rhythm. Theoretically, if there is prolonged retrograde conduction over the His–Purkinje system, producing a markedly delayed His deflection (very long V-H), the “in parallel” activation of the His bundle would appear as a “normal” H-V interval. In this case, one must demonstrate that the His deflection is not a requisite for subsequent ventricular activation and thus is not a reflection of bundle branch reentry. Certain criteria are necessary for the diagnosis of bundle branch reentry, all of which provide P. The mechanisms of bundle branch reentry and its variants are discussed in greater detail later in this chapter. B: The schema shows that propagation of the impulse from the reentrant circuit to the His–Purkinje system is more rapid than that to the remainder of the myocardium, resulting in a short V-H interval. In this instance, conduction to the His–Purkinje was far more rapid than that to the ventricular myocardium, resulting in early His–Purkinje activation. These differences make it mandatory that these arrhythmias not be lumped together in terms of response to stimulation, effects of pharmacologic therapy, effectiveness of ablation, and clinical outcome. Anatomic Substrate The most common anatomic substrate for all these arrhythmias is chronic coronary artery disease, usually associated with prior infarction. Arrhythmias that are due to coronary artery disease are the only ones for which we have a reasonable understanding of the pathophysiologic substrate required for their genesis.
Defcits in nonverbal communicative behaviors used for social interaction buy 1 mg propecia with amex hair loss cancer, ranging for example buy propecia 5 mg visa hair loss in men experiencing, from poorly integrated verbal and nonverbal communication; to abnormalities in eye contact and body language or defcits in understanding and use of gestures; to a total lack of facial expressions and nonverbal communication. Defcits in developing, maintaining and understanding relationships, ranging for example, from difculties in adjusting behavior to suit various social contexts; to difculties in sharing imaginative play or in making friends; to absence of interest in peers. Specify current severity: Severity is based on social communication impairments and restricted, repetitive patterns of behavior (Table 6. Insistence on sameness, infexible adherence to routines, or ritualized patterns or verbal nonverbal behavior (e. Hyper or hyporeactivity to sensory input or unusual interests in sensory aspects of the environment (e. Intellectual disability and autism spectrum disorder frequently co-occur; to make comorbid diagnoses of autism spectrum disorder and intellectual disability, social communication should be below that expected for general developmental level. Individuals who have marked defcits in social communication, but whose symptoms do not otherwise meet criteria for autism spectrum disorder, should be evaluated for social (pragmatic) communication disorder. Specify if: z With or without accompanying intellectual impairment z With or without accompanying language impairment z Associated with a known medical or genetic condition or environmental factor z Associated with another neurodevelopmental, mental, or behavioral disorder. With early diagnosis, improved care, Management of abnormal behavior (behavior modif- and intensive behavioral therapy, the proportion of sub- cation). For details, See factors operating before pregnancy, during pregnancy, Chapter 23 (Intrauterine Infections). Tese dis- tions, over criticism, discrimination, unfavorable compari- orders are relatively stable, internalized and difcult to son, over or under discipline, dominance by the parents, treat than the adjustment reactions, but less than neurosis marital disharmony, etc. Common examples of this category are failure to attend to the normal needs of the child, unfavorable nail biting, thumb sucking, somnambulism and enuresis. Parents z Scholistic problems: Reading, writing or mathematical disability, z Misinterpreted behavior repeated failures, absenteeism, truancy, school phobia, aggres- z Mismatched expectations siveness. Even in frank cases, parents are 103 child, a stepchild, a mentally or physically handicapped reluctant to consult a psychiatrist due to social taboos. He is unlikely to Not infrequently, parental attitudes may well be a cocktail fulfll this function completely and earnestly without the of overprotection and rejection at diferent times, depending knowledge of fundamentals of child psychiatry. Etiology: It lies in disturbed relationship with parents/ It is a useful intervention for many behavioral dis- caregivers and non-stimulating environments. Clinical features: Two types are recognized: To be of real beneft, the change should be learned and 1. Pathologic: In infants with mental retardation (usu- ior is often imposed on children and/or parents. Te hallmark of rumination is malnutrition, weight Secondly, while counseling for a change in behavior, any loss and growth delay. Generally speaking, mothers are expected to Treatment: Reinforcing correct eating behavior. However, it is desirable that the father too take interest and responsibility in this pursuit. Te term, pica (Latin: magpie), refers to eating of substanc- Counseling should also aim at difusing the guilt feeling es other than food (non-edible/non-nutritive items), e. Pica as a manifestation of inclination for mouthing other parents with similar problems and providing and tasting in the absence of any associated problem may guidelines for coping with them. Etiology: An association of pica with mental retarda- Te feld of child psychiatry primarily deals with tion is a category per se. Here we are largely concerned identifcation and handling of the emotional, behavioral with pica in otherwise normal children. Its knowledge situation, pica usually occurs in children from the lower in case of a pediatrician is of particular importance, at least strata of society with suggestions of parental neglect and for two reasons. Asso- First, his frst contact with the child and his parents ciated malnutrition with worm infestation and vitamin and the subsequent contacts uniquely contribute to and mineral defciencies is common. Whether these are evaluating the development of the child and advising the cause or efect of pica remains unclear. Intes- but also for seeking psychiatric consultations as and tinal parasitic infestations are generally associated. Besides, there is a disorders are subtle and are likely to be passed of risk of chronic lead poisoning which can be dangerous. Te subject consumes a large amount of food in a which becomes palpable as a big lump in the upper abdo- short amount of time followed by an attempt to rid himself men (trichobezoar), particularly after meals. Purging is attained by Te perverted appetite in such children is generally self-induced vomiting, taking a laxative or diuretic, fasting a manifestation of psychologic cause which should be and/or excessive exercise. Etiology: Tere is an extensive concern for body Treatment: In view of the common association weight. Many individuals with bulimia nervosa also between pica and worm infestation plus vitamin and have an additional psychiatric disorder. Psychotherapy (especially behavior modifcation) is of Family histories of alcohol and substance abuse, value in cases where pica is associated with psychosomatic mood and eating disorders may be present. Treatment: It revolves around psychotherapy along with antidepressant and antipsychotic agents. It is quite a common problem, Intense fear of gaining weight, causing anxiety to parents. A distorted perception of body weight and body image, Etiology: Factors contributing it include overindul- and gence by parents who may well be themselves fussy Amenorrhea in postmenarcheal girls. Teenagers with anorexia nervosa place a high value on Management: It revolves around such behavioral controlling their weight and shape, using extreme eforts strategies as: (restricting diet and indulgence in too much exercise) that z A pleasant, conducive atmosphere at main meal tend to signifcantly interfere with activities in their lives. Restrictive: The patient not only severely restricts z A pleasant presentation of foods the amount of food intake, but also controls calorie z Offering small to moderate serving at a time intake by vomiting after eating or by misusing z Avoiding eating energy foods in between main meals laxatives, diet aids, diuretics or enemas. They may z Parents and other family members setting exam- also try to lose weight by exercising excessively. Non-restrictive: The patient with anorexia binges ments about the food being served. Tis is the time to begin toilet training in Accompanying manifestations include anxiety, depres- the form of simple instructions given in a holistic manner. Frequently induced vomiting and abuse of diuretics In no case, parents should use force or pressurize him. For sev- 3 months for training though they are likely to need some erely malnourished subjects, nutritional rehabilitation, help for washing/cleansing body part up to 5 years of age preferably in a health facility, is essential. Te term, enuresis, denotes normal urinary bladder empty- z Chronological age is at least 5 years of age (or equivalent develop- mental level). A proportion of children Specifc types: Nocturnal (night-time) only, diurnal (day-time) only, nocturnal and diurnal. Types Diagnosis Four types are recognized based on day-time symptoms: Tis should include a detailed interview with the parents as 1.
By O. Gelford. University of Saint Mary.