Bhagwan Satiani

Normothermic rapid volume replacement for hypovolemic shock: an in vivo and in vitro study utilizing a new technique.

Hypovolemic shock secondary to intraoperative or traumatic hemorrhage requires urgent, aggressive resuscitation to achieve a successful outcome. Common difficulties encountered include the need for venous access, restoration of blood volume, and most important, maintenance of normothermia. The rapid solution administration set utilized in this study addresses the above limitations. Venous access is quickly accomplished by the percutaneous insertion of a large-bore catheter into the central venous system. The set requires only one central venous entry site for adequate fluid resuscitation. Expeditious restoration of blood volume is accomplished by gravity-induced infusion of crystalloids, colloids, and blood products at flow rates of up to 1,600 ml/minute. High flow rates are obtained by utilizing low-resistance filters and large-bore perfusion tubing. Avoidance of transfusion-induced hypothermia is addressed by incorporation of an extracorporeal heat exchanger into the administration set. The infusate temperature is maintained at 37 degrees C regardless of the administration rate or the initial fluid temperature. In vitro and canine in vivo testing demonstrated no significant hemolysis of the transfused blood and allowed maintenance of normothermia.

Correlation of metabolic acidosis with outcome following injury and its value as a scoring tool.

This study looked at preresuscitation arterial pH as a predictor of outcome in injury. Seriously injured patients admitted to the Trauma Service over a 5-month period were evaluated prospectively. Data collected included basic patient demographics, initial arterial blood gas determinations (ABGs) including pH, bicarbonate (HCO3), base deficit or excess (BASE), admitting trauma score (TS), discharge injury severity score (ISS), total blood products used for initial resuscitation (TBP), and outcome. There were 191 patients averaging 34.7 years old with average TS 13.6, ISS 19.5, initial pH 7.38±0.09, HCO3 20.9±4.0, and BASE −3.3±4.7. The average TBP was 1309 cc, and overall mortality was 13/191 (6.8%). Comparing survivors to nonsurvivors, the ISS (18.2 vs. 38.3), TS (14.1 vs. 7.8), TBP (976 vs. 5881 cc), HCO3 (21.1 vs. 17.6), and BASE (−3.1 vs. −5.8) data were significantly different; pH (7.38 vs. 7.36) and age (34.4 vs. 38.5) were not. Using multiple regression with TBP as the dependent variable, BASE, age, TS, and to a lesser extent pH and HCO3 correlated (r=0.536; p<0.001); using outcome as the dependent variable, only TS and age correlated (r=0.465; p<0.0001). Although metabolic acidosis (pH, HCO3, BASE) predicts the TBP used, it does not improve on TS and age for predicting outcome.RésuméLe but de cette étude a été de détérminer la valeur pronostique du pH artériel pré-réanimation dans lévolution dun traumatisé. Il sagit dune évaluation prospective de patients victimes de traumatismes graves réalisée dans un Service de réanimation et de traumatologie pendant cinq mois. Les données recueillies étaient létat civil du patient, les gaz du sang initiaux (GDSI), y compris le pH, les bicarbonates (HCO3), le déficit ou lexcès en base (BASE), le score initial de traumatisme (Trauma Score) (TS), le score de sévérité à la sortie (ISS), lensemble de prduits sanguins utitlisés pour la réanimation initiale (TBP) et lévolution. Chez 191 patients ayant un âge moyen de 34.7 ans, le TS initial était de 13.6, lISS de 19.5, le pH de 7.38±0.09, le HCO3 de 20/9±4.0, et la BASE de −3.3±4.7. Le TBP moyen était de 1309 ml et la mortalité globale de 13/191 (6.8%). En comparant les survivants aux non survivants, lISS était de 18.2 vs 38.3, le TS de 14.1 vs 7.8, le TBP de 976 vs 5881 ml, le HCO3 de 21.1 vs 17.6, et la BASE de −1.1 vs −5.8, toutes les différences étant significatives. Par contre, les différences entre lâge (34.4 vs. 38.5), et le pH (7.38 vs. 7.36), ne létaient pas. En utilisant une régression multiple avec le TBP comme variable indépendante, il y avait une corrélation significative (r=0.536: p<0.001) entre la BASE, lâge, le TS, et à un degré moindre, le pH et le HCO3. Lorsquon prend comme variable dépendante lévolution, seuls le TS et lâge étaient significativement corellés (r=0.465, p<0.0001). Bien que lacidose métabolique (pH, HCO3, BASE) puisse prédire le TBP, il nintervient pas dans la prédiction de lévolution.ResumenEn el presente estudio se investigó el pH arterial determinado antes de la reanimación como factor de predicción del resultado final en pacientes traumatizados. Evaluation prospectiva de pacientes severamente traumatizados que ingresaron al Servicio de Trauma en un periodo de cinco meses. Se recolectó información sobre los aspectos demográficos de los pacientes, las determinaciones iniciales de gases arteriales incluyendo pH, bicarbonato (HCO3), exceso o déficit de base (BASE), escala de gravedad del trauma (“trauma score”, TS), escala de gravedad de la lesión al egreso (“injury severity score”, ISS), total de productos sanguíneos (“total blood products”, TBP) utilizados en la reanimación inicial y resultado final. 191 pacientes con edad promedio de 34.7 años, y valores promedios de: TS 13.6, ISS 19.5, pH 7.38 ±.09, HCO3 20.9 ±4.0, BASE −3.3 ±4.7; el promedio de TBP fue de 1309 cc y la mortalidad global de 13/191 (6.8%). Al comparar los sobrevivientes con los que no sobrevivieron: ISS (18.2 vs. 38.3), TS (14.1 vs. 7.8), TBP (976 cc vs. 5881 cc), HCO3 (21.1 vs. 17.6) y BASE (−3.1 vs. −5.8), significativamente diferentes; pH (7.38 vs. 7.36) y edad (34.4 vs. 38.5), no significativamente diferentes. Utilizando la regresión múltiple con TBP como la variable dependiente, se encontró correlación de BASE, edad, TS y, en menor grado, de pH y HCO3 (R=0.536, p<0.001); utilizando el resultado final como la variable dependiente, sólo el TS y la edad muestran correlación. Aunque la acidosis metabólica (pH, HCO3, BASE) predice los TBP utilizados, no es superior al TS ni a la edad como factores de predicción del resultado final. Por consiguiente, la acidosis no debe ser usada como factor de signification en el desarrollo de escalas de gravedad del trauma.

Natural History of Nonoperated, Significant Carotid Stenosis

One-hundred sixty-seven patients with 190 carotid arteries (109 asymptomatic) demonstrating 50-99% stenosis by arteriography (80), duplex scanning, or other noninvasive techniques were followed from 1-84 months (mean 24.2) for evidence of brain infarct, transient ischemic attacks, or vertebrobasilar symptoms. Thirty-nine arteries (20.5%) were symptomatic at last follow-up, including 13 (6.8%) producing ipsilateral strokes. Twenty-eight sides underwent carotid endarterectomy, 16 for symptomatic lesions at a mean interval of 14.5 months after the initial diagnostic study, with no neurologic deficit. Twenty-seven patients (16.2%) died, eight from stroke (30%), and 12 from cardiac causes (44%). In initially symptomatic sides, the incidence of any subsequent neurologic event (28.7%) or stroke/transient ischemic attack (25%) was significantly greater than in asymptomatic arteries (14.6% and 12%, respectively) (p less than .05). Carotid arteries with greater than 80% stenosis by arteriography and duplex scanning had a 46% incidence of further symptoms and 41.6% stroke/transient ischemic attack rate compared to 19.6% and 15%, respectively, in arteries with less than 80% stenosis (p less than .01). Cumulative life table analysis at 12, 24 and 36 months showed greater than 80% stenosed arteries to have stroke/transient ischemic attack free rates of 69%, 50.5%, and 21.6% compared to 91%, 83.7%, and 76% for arteries with less than 80% stenosis (p less than .05). At a mean follow-up of over two years, nonoperated carotid stenosis (greater than 50%) carries a 20.5% risk of neurologic symptoms and a 6.8% risk of stroke, 61.5% of strokes being fatal. Symptomatic carotid stenosis had a significantly greater incidence of ensuing neurologic events than asymptomatic arteries.(ABSTRACT TRUNCATED AT 250 WORDS)

A Prospective Randomized Trial of Aspirin in Femoral Popiteal and Tibial Bypass Grafts

A prospective, randomized clinical trial to study the effect of aspirin on late patency of femoral popliteal and tibial bypass grafts is reported. One hundred limbs in 93 patients were randomized to receive daily 650 mgs aspirin postoper atively (ASA, n=45) or no aspirin (NASA, n=55). Indication for surgery was limb salvage in 88% and poor runoff (0-1 vessel) was present in 68%. Graft material consisted of autogenous vein (AV) in 63, expanded PTFE in 82 and composite grafts in five limbs. Distal anastomosis was to the popliteal artery in 72 limbs, tibial vessels in 19 and sequential in nine limbs. Patient followup ranged from 1-51 months (mean 12.97). Sixteen (16%) grafts occluded late, eight each in the ASA and NASA groups, (p>.05). No significant differences in graft patency existed between ASA and NASA groups in limbs with AV (88.5% vs 92.9%) or PTFE grafts (74% vs 62%) (p>.05). A total of 21 (19%) anastomoses occluded. No differences were noted between ASA and NASA limbs, although patency in AV was greater than PTFE (p < .05). Cumulative patency rates were 84.4% at 12 months, 81.5% at 24 months, 67.3% at 36 months and 52.4% at 48 months (ASA vs NASA, p>.05). Therefore, daily administration of 650 mgs of aspirin did not appear to influ ence late graft patency of femoral popliteal and tibial AV or PTFE bypass grafts at a mean followup period of 12.97 months.

Rapid Volume Replacement With Warmed Blood and Fluids

A prospective clinical study was undertaken in 50 consecutive patients suf fering from severe traumatic shock to evaluate the clinical efficacy of a set for rapid administration of solutions (RSAS), which allows for rapid infusion and simultaneous warming of blood and fluids. The mechanism of injury was blunt in 37 patients and penetrating in 13. Admission trauma score averaged 7.5, and the injury severity score averaged 46. Average preresuscitation systolic blood pressure was 71 mmHg, pulse was 105 beats/minute, and temperature was 34.3°C. Initial resuscitation was with the RSAS, and total fluid infused in the first twenty-four hours averaged 4,632 mL of blood, 1,914 mL of blood prod ucts, and 11,248 mL of crystalloid. The average postresuscitation systolic blood pressure was 120 mmHg, pulse was 96 beats/minute, and temperature averaged 34.9°C. Survival at twenty-four hours was 29/50 (58%). There were no local complications of RSAS use and no evidence of infusion-related coagulopathy. The RSAS provided an effective and safe way to infuse large volumes of blood and fluid at body temperature.

Normothermic rapid volume replacement in vascular catastrophes using the infuser 37

Twenty patients (Group 1) with a mean age of 38.5 +/- 16 years and an admission Trauma Score of 7.26 +/- 5.9, suffered 27 vascular injuries and were resuscitated with the Infuser 37 (IN-37) with an integral heat exchanger. Admission systolic BP averaged 46.47 mmHg (seven with absent vital signs). A mean of 7,030 ml of blood, 3,313 ml of colloid and 13,630 ml of crystalloid per patient was given in less than 24 hours, mostly through the IN-37. Twelve thoracotomies, nine laparotomies, and one extremity exploration were performed. Twelve patients, seven with a Trauma Score less than 3, died in less than 24 hours of exsanguination. The survival rate was 40% at 24 hours and 25% at 30 days. Six patients (Group 2) with a mean age of 70.33 +/- 8.3 years underwent operation for ruptured aortic aneurysm (5 pts), and elective aortic aneurysm (1 pt) with a 66% survival at 24 hours. Admission systolic blood pressure averaged 84 mmHg. A mean of 3,895 ml of blood, 1,900 ml of colloid and 7,733 ml of crystalloid per patient was administered in less than 24 hours, mostly through the IN-37. The IN-37 provides a safe and simple means of normothermic, rapid volume replacement in hemorrhagic shock. Its use in critically ill but potentially salvageable patients with vascular injuries and aortic aneurysm may avoid the consequences of prolonged hypoperfusion and hypothermia.

Angiographic follow-up after laser-assisted balloon angioplasty *

PURPOSEnThe purpose of this study was to obtain angiographic documentation of patency and recurrence rates after laser-assisted balloon angioplasty.nnnMETHODSnA prospective assessment of laser-assisted balloon angioplasty (LABA) was performed in 35 limbs of 33 patients with femoral popliteal atherosclerotic disease. There were 21 male and 12 female patients with a mean age of 60.6 years. Indications were intermittent claudication in 19, rest pain in nine, and ischemic ulcer/gangrene in seven limbs. There were 23 totally occluded (mean length 6 +/- 3.8 cm) and 12 stenotic arteries. LABA was achieved with a pulsed Nd:YAG laser with 10 to 25 W and a 2.2/3 mm sapphire probe, followed by balloon dilatation in all but four limbs.nnnRESULTSnImmediate technical success (< or = 50% residual stenosis) was achieved in 27 (77%) of 35 limbs. Mean ankle/brachial index improved from 0.49 to 0.80 (p < 0.05). Major complications included three perforations, three dissections, and two emboli. Two additional limbs required operation at less than 30 days for a 30-day patency rate of 71.4%. Long-term clinical and noninvasive follow-up ranged from 1 to 55 months (mean 17.68 months). Twenty-nine angiograms were obtained from 3 to 49 months after LABA. Nineteen limbs underwent at least one angiogram, seven underwent two, and three limbs underwent three angiograms. Eleven of the 19 limbs showed evidence of restenosis greater than 50%, all within 12 months. The cumulative patency rate was 71.5% at 1 month, 39.7% at 6 months, and 31.3% at 12, 24, and 36 months.nnnCONCLUSIONSnLABA with the Nd:YAG laser has a 30-day success rate of 71.4%. Angiographic follow-up demonstrates a high incidence of restenosis (> 50%), usually within 12 months. Approximately 50% of limbs eventually required reintervention within 1 year. In view of the disappointing early results, the use of LABA must remain strictly investigational.

The influence of contralateral disease on the natural history of nonoperated significant carotid stenosis

The influence of contralateral disease on the natural history of ipsilateral nonoperated carotid stenosis >50% was analyzed in 90 carotid arteries imaged by contrast arteriography or duplex scanning with a mean follow-up of 23.6 months. Ipsilateral stenosis was >80% in 24 arteries and 50–79% in 66 arteries. Contralateral disease was present in 30 (Group I) and absent in 60 (Group II) patients. In Group I, the contralateral disease consisted of total occlusion in nine (30%), >80% stenosis in five (17%), 50–79% stenosis in 12 (40%) with a mean of 78.6%. No significant difference existed in the incidence of initially asymptomatic vessels (57% versus 67%), stroke (13% versus 2%), or transient ischemic attack (17% each) between Groups I and II on the ipsilateral side (p > .05). New ipsilateral neurologic events occurred significantly more often in arteries with >80% ipsilateral stenosis than those with 50–79% stenosis (p < .02). The incidence of subsequent ipsilateral neurologic events (37% versus 22%), strokes, or transient ischemic attacks (20% versus 13%) was no different in Groups I and II, respectively (p > .05). Combined ipsilateral and contralateral neurologic events occurred significantly more often in patients with contralateral disease (p < .05). Whereas in Group I, new ipsilateral symptoms were significantly more common in initially symptomatic vessels compared to asymptomatic ones (61.5% versus 17.6%, p < .04), no such difference existed in Group II.

Relevance of federal antitrust statutes to clinical practice

With the advent of Medicare prospective payment systems, health care entities and physicians were forced to decrease expenses by sharing services and to increase revenue by attempting to jointly negotiate better reimbursement from third- party payers. Both activities have raised the specter of prosecution under antitrust laws that have been with us for more than a century but are poorly understood by practicing physicians. Recent monopolistic activities in the health care arena have prompted the Federal Trade Commission to file actions under specific acts of Congress, eg, the Sherman Anti-Trust Act, Clayton Act, Federal Trade Commission Act, Robinson-Patman Act, and Celler-Kefauver Act. Inasmuch as it is likely that specialties such as vascular surgery as a business will undergo substantial transformation, physicians need to be aware of the severe civil and criminal sanctions imposed if they are found guilty; fines that are several times actual damages; activities that raise antitrust issues including utilization review, medical staff privileges for competing specialties, participating provider agreements, and predatory pricing; and affirmative defenses and relief available in terms of specific exemptions. As health care providers react, innovate, and adjust to stay solvent, their business strategies will surely continue to be scrutinized for antitrust behavior by federal and state officials. The physician must have a basic understanding of the groundrules that govern any contemplated business strategy so that common pitfalls may be averted.

Are Noninvasive Doppler Arterial Studies Useful in Predicting Success of Infrainguinal Bypass Grafts

The prediction of success of lower extremity bypass grafts based solely on noninvasive Doppler flow data has been questioned. The prognostic value of preoperative Doppler ankle pressures (APR), ankle/brachial indices (ABI), be low-knee pressures (BKPR), above-knee pressures (AKPR), and segmental pressure gradient indices was examined in predicting immediate (IF), late (LF), and overall failure (OF), as well as amputation (AMP) in 168 infrainguinal bypass grafts. Good runoff (2-3 vessels) was present in only 36%, and vein grafts were used in 60% of limbs. OF occurred in 26.7% (IF 6.5%, LF 20.2%) with a mean follow-up of 16.2 months (range 0-63). Major AMP resulted in 17.2% limbs. In 140 limbs with audible Doppler pedal signals, there was no significant difference in AKPR, ABI, or segmental indices between successful and failed grafts. Successful grafts had a higher AKPR (114.8 ± 38.5 vs 100 ± 30.5, p < .05) and BKPR (87.9 ± 30 vs 72.2 ± 23.5, p < .01) compared with failed bypasses. No significant differences in IF, LF, or OF rates were noted in limbs with ABI < 0.2 vs > .02, < .04 vs > .04 or presence/absence of Doppler pedal signals. Preoperative noninvasive Doppler flow studies are invaluable in the diagno sis, grading, and follow-up of unoperated patients with lower extremity arterial occlusive disease or detection of impending graft failure. They do not reliably predict success/failure of infrainguinal bypass grafts in individual patients. Low ABI or absent Doppler pedal signals do not by themselves preclude successful revascularization.