Simple Maneuvers Research Articles

Simple screening tests for peripheral neuropathy in the diabetes clinic.

The utility of rapid and reliable sensory tests appropriate for the diagnosis of neuropathy in the diabetes clinic, rather than as prognostic tools for the prediction of foot complications, has been unclear because of limitations inherent in previous studies. Although clinical practice guidelines recommend annual screening for neuropathy, they are unable to support specific recommendations for screening maneuvers because of a lack of evidence for the validity of screening tests in the medical literature. The objective of this study was to assess the operating characteristics of four simple sensory screening maneuvers as compared with standardized electrophysiological tests in the diagnosis of distal symmetrical polyneuropathy. We assessed four simple tests (the 10-g Semmes-Weinstein monofilament examination [SWME], superficial pain sensation, vibration testing by the on-off method, and vibration testing by the timed method) in 478 subjects with independent blinded evaluations compared against the criterion standard of nerve conduction studies. We present receiver-operating characteristic (ROC) curves, positive and negative likelihood ratios, and sensitivity and specificity values for each test. The four simple screening maneuvers reveal similar operating characteristics. Cutoff points by ROC curve analyses reveal that a positive or abnormal test is represented by five incorrect responses of eight stimuli applied. A negative or normal test is represented by one or fewer incorrect responses of eight stimuli applied. By these criteria, the point estimates of the positive likelihood ratios for vibration testing by the on-off method, vibration testing by the timed method, the SWME, and superficial pain sensation test are 26.6, 18.5, 10.2, and 9.2, respectively. The point estimates of the negative likelihood ratios are 0.33, 0.51, 0.34, and 0.50, respectively The screening tests showed comparable sensitivity and specificity results. The 10-g SWME, superficial pain test, and vibration testing by the on-off method are rapid, each requiring approximately 60 s to administer. The timed vibration test takes longer, and the interpretation is more complicated. The combination of two simple tests (e.g., the 10-g SWME and vibration testing by the on-off method) does not add value to each individual screening test. Annual screening for diabetic neuropathy should be conducted using superficial pain sensation testing, SWME, or vibration testing by the on-off method. The reported operating characteristics for each sensory modality can be applied to positive findings on the physical examination of individual patients to predict the likelihood of neuropathy.

Simple screening tests for peripheral neuropathy in the diabetes clinic

OBJECTIVE — The utility of rapid and reliable sensory tests appropriate for the diagnosis of neuropathy in the diabetes clinic, rather than as prognostic tools for the prediction of foot complications, has been unclear because of limitations inherent in previous studies. Although clinical practice guidelines recommend annual screening for neuropathy, they are unable to support specific recommendations for screening maneuvers because of a lack of evidence for the validity of screening tests in the medical literature. The objective of this study was to assess the operating characteristics of four simple sensory screening maneuvers as compared with standardized electrophysiological tests in the diagnosis of distal symmetrical polyneuropathy. RESEARCH DESIGN AND METHODS — We assessed four simple tests (the 10-g Semmes-Weinstein monofilament examination [SWME], superficial pain sensation, vibration testing by the on-off method, and vibration testing by the timed method) in 478 subjects with independent blinded evaluations compared against the criterion standard of nerve conduction studies. We present receiver-operating characteristic (ROC) curves, positive and negative likelihood ratios, and sensitivity and specificity values for each test. RESULTS — The four simple screening maneuvers reveal similar operating characteristics. Cutoff points by ROC curve analyses reveal that a positive or abnormal test is represented by five incorrect responses of eight stimuli applied. A negative or normal test is represented by one or fewer incorrect responses of eight stimuli applied. By these criteria, the point estimates of the positive likelihood ratios for vibration testing by the on-off method, vibration testing by the timed method, the SWME, and superficial pain sensation test are 26.6, 18.5, 10.2, and 9.2, respectively. The point estimates of the negative likelihood ratios are 0.33, 0.51, 0.34, and 0.50, respectively. The screening tests showed comparable sensitivity and specificity results. The 10-g SWME, superficial pain test, and vibration testing by the on-off method are rapid, each requiring ∼60 s to administer. The timed vibration test takes longer, and the interpretation is more complicated. The combination of two simple tests (e.g., the 10-g SWME and vibration testing by the on-off method) does not add value to each individual screening test. CONCLUSIONS — Annual screening for diabetic neuropathy should be conducted using superficial pain sensation testing, SWME, or vibration testing by the on-off method. The reported operating characteristics for each sensory modality can be applied to positive findings on the physical examination of individual patients to predict the likelihood of neuropathy.

Aesthetic results of treatment of large alopecia with total scalp expansion.

In the last 7 years, 18 patients with large alopecia (approximately one-third of hair-bearing scalp) were treated with 31 tissue expansion procedures. In the previous 44 patients, with various degrees of alopecia treated with conventional tissue expansion technique, the major complication rates were as high as reported in the relevant literature. The clinical experience gained with these cases led us to make some modifications in the surgical technique. We applied some simple surgical maneuvers and Z-plasties to the last 18 cases with large alopecia. The major complication rate of 3.2% observed in this study is comparable to the lower complication rates of 6-12% reported in the literature for different degrees of alopecia. We believe that these simple modifications and meticulous approach improve the results of conventional treatment of alopecia with tissue expansion and flap. In this paper, details of the insertion technique and reconstructive procedures and their relevance to the success rate of the aesthetic treatment of the large alopecia are discussed.

Strategies for improving hemodynamic stability in cardiac-compromised dialysis patients

In hemodialysis patients, structural changes at all levels of the cardiovascular system are common. The presence of these cardiovascular changes is a risk factor for the development of intradialytic hypotension. This explains the clinical observation that the incidence of symptomatic hypotension is high in elderly hemodialysis patients, who often have a history of long-standing hypertension and atherosclerosis, and in hemodialysis patients with cardiovascular disease. With an increasing number of cardiovascular compromised dialysis patients, special attention should be given to this group of patients. As the age of patients on hemodialysis increases steadily, it is a challenge to provide comfortable treatment in these patients by reducing the incidence of symptomatic hypotensive periods. This article describes the use of relatively new and simple clinical maneuvers to reduce the incidence of symptomatic hypotension.

FACES: A Free Flight Autonomous and Coordinated Embarked Solver

FACES is an autonomous and coordinated embarked (on board) conflict solver for Free Flight airspace. It solves conflict by computing simple manoeuvres that guarantees conflict free trajectories for the next 5 minutes (min). Coordination is ensured by giving sequential manoeuvres to aircraft with a token allocation strategy. FACES can be implemented with the current positioning, broadcasting and flight management technology. More-over, it is robust to communication or system failure for time up to one or two minutes. FACES was tested with a traffic simulator on busy traffic days over France. Airspace over level 320 was considered as Free Flight. 638 out of 641 conflicts were solved without using vertical manoeuvres. The 3 remaining conflicts could easily be solved with vertical manoeuvres. The mean delay was less than 30 seconds by aircraft manoeuvred, with a maximum delay of 150 seconds. An airborne implementation of this algorithm can be seriously considered.

From vision to action: Experiments and models of steering control during driving.

Experienced drivers performed simple steering maneuvers in the absence of continuous visual input. Experiments conducted in a driving simulator assessed drivers' performance of lane corrections during brief visual occlusion and examined the visual cues that guide steering. The dependence of steering behavior on heading, speed, and lateral position at the start of the maneuver was measured. Drivers adjusted steering amplitude with heading and performed the maneuver more rapidly at higher speeds. These dependencies were unaffected by a 1.5-s visual occlusion at the start of the maneuver. Longer occlusions resulted in severe performance degradation. Two steering control models were developed to account for these findings. In the 1st, steering actions were coupled to perceptual variables such as lateral position and heading. In the 2nd, drivers pursued a virtual target in the scene. Both models yielded behavior that closely matches that of human drivers.

From vision to action: experiments and models of steering control during driving.

Experienced drivers performed simple steering maneuvers in the absence of continuous visual input. Experiments conducted in a driving simulator assessed drivers' performance of lane corrections during brief visual occlusion and examined the visual cues that guide steering. The dependence of steering behavior on heading, speed, and lateral position at the start of the maneuver was measured. Drivers adjusted steering amplitude with heading and performed the maneuver more rapidly at higher speeds. These dependencies were unaffected by a 1.5-s visual occlusion at the start of the maneuver. Longer occlusions resulted in severe performance degradation. Two steering control models were developed to account for these findings. In the 1st, steering actions were coupled to perceptual variables such as lateral position and heading. In the 2nd, drivers pursued a virtual target in the scene. Both models yielded behavior that closely matches that of human drivers.

Diagnosis and management of the vertiginous patient

This article discusses the anatomy and physiology of the inner ear, the mechanisms of normal balance maintenance, the key points of the history and physical examination, simple and advanced diagnostic maneuvers, common causes of vertigo, and the surgical and medical measures used to mitigate these symptoms.

Central Venous Pressure Monitoring During Bypass

Maintenance of adequate cerebral perfusion pressure (CPP) is of paramount importance in all patients, but especially in cardiac patients undergoing surgery under conditions of cardiopulmonary bypass (CPB). CPB is associated with a significant incidence of neurologic complications, some of which, unfortunately, are irreversible and even fatal. The cause of this neurologic damage is multifactorial and still not completely understood (1). CPB diverts blood flow to an extracorporeal circuit and requires a means to deliver the blood from and then back to the body. Systemic venous return to the CPB circuit is accomplished with specially designed cannulas and occurs by gravity/siphon. Any condition that impairs the passive drainage of blood will cause a decrease in venous return to the pump. If superior vena cava (SVC) drainage is inhibited, the associated venous hypertension increases intracranial pressure and decreases CPP (2). Plochl et al. (3) nicely describe this condition in an animal model, and they conclude that the “observation of internal jugular pressure may be advantageous during initiation of CPB.” Their conclusion, although intuitive to many (as it should be), draws attention to the important question of how to monitor this pressure. We routinely pay close attention to jugular venous pressure, but do so not only throughout the surgical procedure; vigilance is especially important during procedures in which separate venous cannulas have to be used. We continue to often use the pulmonary artery catheter (PAC) during cardiac surgery, and we have observed a high incidence of spurious readings of central venous pressure (CVP) caused by either collapse of intracardiac structures onto the monitoring lumen orifice of the catheter or from the CVP monitoring orifice located in the right atrium when it has been opened to the atmosphere. If a PAC is being used, you can be assured that the CVP lumen is proximal to the SVC cannula if it registers a pressure change when running IV fluids through the sideport of the introducer. If this is not the case, we transduce the CVP during CPB from the sideport of the PAC introducer. Another technique, used in children and adults with central venous catheters in place, is to ballot the neck on the side opposite of where the central venous catheter is located. If a transient change in the CVP tracing occurs, it is likely that the reading reflects a true SVC CVP; if no change is noted, the pressure may be from a catheter port located below the SVC cannula. Another aspect of monitoring CVP and CPP during CPB in our institution is that we set the alarms on our CVP monitors to signal increases in CVP, which may occur with manipulations of the heart and/or SVC cannulas. We have been impressed by how frequently we are able to identify altered SVC and cerebral venous drainage with these alarms when it is not evident from the surgical field. In summary, we recommend these two simple maneuvers to avoid potential neurologic disasters, and we thank Plochl et al. (3) for the interesting study they reported. Felipe Urdaneta MD Nikolaus Gravenstein MD

Hiccup

Hiccup is defined as involuntary contractions of the diaphragm and the auxiliary respiratory muscles, mostly in irregular series, followed by glottic closure, thereby producing a typical "hiccupping" inspiration. This is a physiologic phenomenon, which already exists in utero. Hiccup is believed to be a gastrointestinal reflex; however, function and the reflex arch are hypothetical. Acute hiccup is distinguished from pathological, chronic hiccup, defined by a duration executing 48 h, or recurrent episodes. Among approximately 100 causes for hiccup, the most common are located in the gastrointestinal tract, with gastro-esophageal reflux as the most important. While the respiratory effect is generally negligible, alkalosis may ensue in tracheotomized patients due to hyperventilation. A stepwise management plan for patients with hiccup is presented. If simple physical maneuvers and causal therapy fail, or causal therapy is impossible, the treatment of choice is medical, with baclofen. Interruption of the reflex arch may be causal therapy or be considered as a last resort.

Can diaphragmatic contractility be assessed by twitch airway pressures in patients with chronic obstructive pulmonary disease?

In healthy subjects and in patients without lung diseases, twitch airway pressure (Paw(tw)) responses to phrenic nerve stimulation can be used to predict twitch esophageal pressure (Pes(tw)) and twitch transdiaphragmatic pressure (Pdi(tw)), thus overcoming the need for placement of esophageal and gastric balloons. The aim of this study was to determine whether measurements of Paw(tw) combined with simple maneuvers could be used to predict Pes(tw), and possibly Pdi(tw), in patients with severe chronic obstructive pulmonary disease (COPD) (n = 12). Stimulations delivered at relaxed FRC produced a correlation coefficient (r) between Paw(tw) and Pes(tw) of 0.44 (p < 0.001) and of 0.62 (p < 0.001) during stimulations while patients performed a gentle exhalation from FRC. Stimulations performed during a gentle inhalation produced a good correlation between Paw(tw) and Pes(tw) (r = 0.92, p < 0.001); however, the limits of agreement between Paw(tw) and Pes(tw) were wide. Correlations between Paw(tw) and Pdi(tw) during the three experimental conditions were weak. In conclusion, during a gentle inspiratory effort in patients with severe COPD the correlation between Paw(tw) and Pdi(tw) was weak, whereas the correlation between Paw(tw) and Pes(tw) was good, but it was not sufficient to allow the prediction of Pes(tw) from Paw(tw) in all patients.

Grip Force Control Capabilities of Older Adults, Revisited

This cross-sectional study examined the effects of age on the dynamic coordination and control of grip force with external force applied with a simulated hand tool. Grip force coordination capabilities were hypothesized to decline with age in light of previous studies examining simple lift and static hold maneuvers with a precision grip. Subjects performed a force-matching task in which dynamic forces were applied with the simulated tool. Subjects were given visual feedback regarding the applied force magnitude but not the grip force magnitude. Grip force control efficiency was measured by the ratio of grip to applied force and the degree of parallel modulation in grip force with respect to applied force. The measures of grip force control efficiency revealed no statistically significant differences (p &gt; 0.05) between the younger (&lt;64 years) and older (65+ years) subject groups. Older adults, when prudently screened for visual and motor impairments, performed equivalently to younger adults in terms of grip force coordination efficiency.

Current management of Helicobacter pylori infection.

Helicobacter pylori infection continues to be one of the hottest topics in gastroenterology, challenging the primary care physician daily with the clinical application of its new developments and frequency of involvement in differential diagnosis. This article offers the primary care physician a practical approach to the dyspeptic office patient that emphasizes the differential diagnosis of H pylori. Included is a strategy for rapid patient evaluation through key questions in the history, simple maneuvers in the physical examination, and a logical approach to testing and therapy based on the latest literature. The recommendations for all these office-based steps are designed to be efficient, cost-effective, and clinically relevant.

Trigeminovagal Reflex During Repair of a Nasal Fracture Under General Anesthesia

The trigeminovagal reflex (TVR), probably best known as the oculocardiac reflex when it occurs during ophthalmic surgery, is manifested by cardiac bradyarrythmias. The TVR has been associated with intraoperative deaths [1] and can occur with non ophthalmic surgery, primarily maxillofacial surgery [2]. We report the occurrence of TVR after repair of a nasal fracture under general anesthesia. Case Report A healthy, 36-yr-old woman was scheduled for closed reduction of a traumatic nasal fracture. Before the induction of general anesthesia, her heart rate (HR) was 84 bpm, blood pressure was 140/60 mm Hg, and arterial oxygen saturation (SaO2) was 98%. General anesthesia was induced with the IV administration of fentanyl (150 [micro sign]g), lidocaine (100 mg), and propofol (150 mg), and 80 mg of IV succinylcholine was used to facilitate endotracheal intubation. Anesthesia was maintained with 1.0%-1.5% sevoflurane, 70% nitrous oxide, and 30% oxygen. No hemodynamic changes were apparent during the 10-min surgical procedure, the SaO2 was 100%, and the end-tidal carbon dioxide level was 32-36 mm Hg, as measured by capnography. After surgery, a malleable plastic splint was formed across the nasal bridge to stabilize the fracture site. Manual pressure was applied over the nose to shape the splint. Seconds after application of the splint, the patient's HR decreased from 72 to 32 bpm. The surgeons were notified, and the immediate administration of atropine 200 [micro sign]g IV increased the HR to 120 bpm. Within 2 min, the HR returned to 90 bpm. Further manipulation of the nasal splint resulted in a bradycardia of 25 bpm. Release of the pressure increased the HR to 60-70 bpm without the administration of atropine. Manual pressure was applied only over the nose, and at no time was there pressure over the eye. One further episode of bradycardia (HR 45 bpm) was noted before completion of the procedure. No bradycardic episodes occurred in the postanesthesia care unit, and the patient was discharged after 45 min. Discussion The literature describing bradycardia mediated via the TVR during ophthalmic surgery is extensive. The neurologic pathway defining the reflex is well described: the afferent limb of the reflex arc involves neuronal transmission from the orbital structures to the ciliary ganglion, the ophthalmic division of the trigeminal nerve, and the sensory nucleus of trigeminal nerve near the fourth ventricle. The efferent limb travels via the vagus nerve to the myocardium [3]. However, the maxillary (II) and mandibular (III) divisions of the trigeminal nerve may also contribute to the afferent pathway of the reflex arc, and TVR-mediated bradyarrythmias have been described during mandibular and maxillary osteotomies [4]. Even simple maneuvers, such as mouth opening, may cause life-threatening TVR-mediated asystole in the anesthetized patient [5]. The nasal bridge is innervated by sensory branches of the maxillary (II) division of the trigeminal nerve. In our patient, external pressure applied over the nasal bridge after surgery while forming the nasal splint triggered the TVR arc. We could not immediately explain the first episode of bradycardia. However, when the second episode occurred, a cause-and-effect relationship between the external pressure applied over the nasal bridge and the decrease in HR was appreciated. Hypoxia and hypercarbia increase the incidence of TVR, as does light anesthesia [6]. Our patient was not hypoxic or hypercarbic. The end-tidal concentration of sevoflurane was <0.5% because we anticipated the emergence from anesthesia. The low anesthetic concentration may have contributed to the TVR in our patient. Other factors associated with an increased incidence of TVR include the use of drugs such as halothane, vecuronium, atracurium, succinylcholine, fentanyl, alfentanil, and sufentanil [7]. Our patient received a relatively small (2.5 [micro sign]g/kg) dose of fentanyl on induction of anesthesia without causing a decrease in HR. Similarly, no bradycardia was noted after the injection of succinylcholine. Classically, the TVR is reported to "fatigue" with repeated application of the triggering stimulus [8]. It is possible that the moderate bradycardia noted with the last episode and the normal HR seen in our patient after application of the splint, despite some persistent pressure over the nose, was a result of such fatigue. In summary, we describe the occurrence of the TVR during the application of a malleable splint for the repair of a nasal fracture. Communication with the surgical team is essential, and cessation of the precipitating stimulus is the first and most important therapeutic step. Afferents other than the ophthalmic (I) division of the trigeminal nerve can be responsible for the reflex arc, and the TVR should be part of the differential diagnosis in all cases of unexplained bradycardia during operations on the face.

Idiopathic Chronic Hiccup (ICH)

Associate Professor of Anesthesiology;y-okuda@dokkyomed.ac.jp(Okuda)Professor; First Department of Anesthesiology; Dokkyo University School of Medicine; Mibu, Tochigi, Japan (Kitajima)Research Associate; Department of Anesthesiology; Kansai Medical University; Osaka, Japan (Asai)In Reply:-We did not claim that “the failure of simple hiccup-terminating maneuvers warrants proceeding directly to potentially damaging 'last-resort' maneuvers such as phrenic nerve interruptions.” Instead, we fully agree with Dr. Petroianu's claim that “the logical next step (after failure of simple maneuvers) is the use of appropriate drugs.” Our statement, “block of the phrenic nerve has been suggested as 'the last resort,”' [1]means that the use of this block should be considered if other less-invasive methods, including the use of potentially effective drugs, have failed. Most patients with intractable hiccups are referred from other departments in which a variety of methods, including potentially effective drugs such as baclofen, have been used in vain, although we did not described these explicitly.The main point we made in our report [1]was not advocating the phrenic nerve block but that the use of electric nerve stimulation enables one to avoid unnecessary attempts at repeated blocks. In fact, in one of our patients, [1]we judged that a successful block of the phrenic nerve would not decrease hiccups and abandoned this method. There is no “holy grail” for intractable hiccups: neither baclofen nor phrenic nerve block is always effective. The importance-we believe-is to judge whether each treatment method is effective in each patient and to stop ineffective methods at an early stage.Yasuhisa Okuda, M.D.Associate Professor of Anesthesiology;y-okuda@dokkyomed.ac.jpToshimitsu Kitajima, M.D.Professor; First Department of Anesthesiology; Dokkyo University School of Medicine; Mibu, Tochigi, JapanTakashi Asai, M.D., Ph.D.Research Associate; Department of Anesthesiology; Kansai Medical University; Osaka, Japan(Accepted for publication July 7, 1998.)

Hypermobility Syndrome

Hypermobility Syndrome

Impact of respiratory maneuvers on cardiac volume within left-breast radiation portals.

Late cardiac morbidity and mortality have been reported among left-breast cancer survivors treated with radiation therapy. Radiation-induced cardiotoxicity is affected by the volume of myocardium included in the radiation portals. We hypothesize that simple respiratory maneuvers may alter the position of the heart relative to the portals without altering the radiation dose delivered to the breast. Fourteen healthy female adult volunteers underwent cardiac MRI to determine the cardiac volume included in the typical left-breast radiation field during respiratory maneuvers. Cardiac volume within the radiation portals was assessed from a transverse stack of 14 1-cm-thick contiguous slices covering the entire heart, obtained during breath holding at end-tidal volume (baseline), deep inspiration, and forced expiration. Thirteen subjects (92%) had inclusion of a portion of the heart within the radiation portals at end-tidal volume (median, 20.9 cm3; range, 1.3 to 88.4 cm3). In these subjects, inspiration decreased the cardiac volume included within the radiation portals (median change: -10.7 cm3 [-40.2%], P<.001 versus end-tidal volume), whereas expiration increased the cardiac volume included (median change: 4.0 cm3 [21.5%]; P<.001 versus end-tidal volume). Inclusion of a portion of the heart in the left-breast radiation field is common. The use of simple inspiratory maneuvers significantly decreases cardiac volume within the radiation portals. Such an approach during delivery of radiation therapy may allow for preservation of radiation dosage to the breast while reducing cardiac involvement and subsequent mortality.

Venous Bleeding During Transsphenoidal Surgery

Venous bleeding during transsphenoidal surgery for resection of pituitary tumors is a common problem that interferes with the performance of the surgical procedure. In this study, data were collected prospectively from 50 patients to determine whether there were pre- or intraoperative factors (e.g., patient demographics, type and grade of pituitary tumor, intraoperative hemodynamics) associated with venous bleeding which might be used to predict its occurrence. In addition, central venous pressure (CVP), and cavernous sinus pressure (CSP) were measured in 13 patients to evaluate the relationship of these pressures to each other and to the severity of venous bleeding. During resection of the pituitary tumor, the severity of venous bleeding was graded as minimal, moderate, or severe, the latter two grades requiring therapeutic intervention. Moderate bleeding requiring intervention occurred in 15 of the 50 patients, and resolved in all cases. Moderate bleeding was not related to CSP or CVP, and no specific associated factor was observed. CSP was not correlated with CVP, and was higher than that predicted from the CVP and the position of the patient or the hydrostatic gravitational pressure gradient. These results suggest that it is not possible to predict in advance which patients will have problems with venous bleeding, but that simple therapeutic maneuvers are effective.

Massive Hemorrhage From Renal Vein Injury During Percutaneous Renal Surgery: Endourological Management

Although minor venous injuries respond to simple maneuvers, major venous injuries pose a significant therapeutic problem and may be under diagnosed. We present our experience with major injury to the renal vein during percutaneous renal surgery. Four patients had massive hemorrhage during percutaneous renal surgery associated with major injury to the renal vein, and 3 also had renal insufficiency. All 4 patients and 1 additional patient with renal insufficiency and massive hemorrhage from an arteriovenous fistula following percutaneous renal surgery were treated nonoperatively with a selectively positioned and inflated Council balloon catheter. Hemorrhage was controlled and renal function was unaffected in all 5 patients. Renal vein injuries can be associated with massive hemorrhage. Patients with major vascular injuries from percutaneous renal surgery and concomitant renal insufficiency can be treated without open exploration or angiographic embolization using a Council balloon catheter.

Role of Physical Countermaneuvers in the Management of Orthostatic Hypotension: Efficacy and Biofeedback Augmentation

To evaluate the efficacy of various physical countermaneuvers in reducing orthostatic hypotension and its associated symptoms and to assess the efficacy of biofeedback training in enhancing the effectiveness of physical countermaneuvers. In nine study subjects with neurogenic orthostatic hypotension, four training sessions on physical countermaneuvers were performed after tilt-up, three with visual feedback on the effect of physical countermaneuvers on blood pressure and other cardiovascular variables. Blood pressure change and orthostatic symptoms during tilt-up were determined, as were the changes in total peripheral resistance, stroke index, and heart rate. The five female and four male patients had a mean age of 53 years and a mean duration of symptoms of 4.2 years. On an orthostatic symptom scale of 0 to 10, these patients had a mean symptom score of 7.3. The increment in systolic blood pressure was better for some maneuvers (such as leg crossing and a combination) than others (such as neck flexion and abdominal contraction). Three patterns of responses to biofeedback were found. Simple maneuvers such as squatting did not improve with training; visual feedback was needed for maneuvers such as thigh contraction, and performance declined without biofeedback; the third pattern, seen in maneuvers such as leg crossing, showed continued improvement with training, even without biofeedback. A survey at 3 to 4 months after training revealed continued use of physical maneuvers (3.8 +/- 3.1 per day), increased standing time with each episode of presyncopal symptoms (8.3 +/- 5.8 minutes), and continued global symptomatic improvement. Total peripheral resistance, but not heart rate or stroke index, showed significant regression with blood pressure improvement. Physical countermaneuvers are efficacious in reducing orthostatic hypotension, can be augmented by use of biofeedback, and may significantly improve the functional outcome. The major mechanism of improvement is an increase in total peripheral resistance, presumably by reducing the vascular capacitance.