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Background: Patients undergoing major arterial reconstruction have traditionally been transfused with red blood cells to keep hemoglobin concentrations above 10 g/dL in order to prevent anemia-induced myocardial ischemia. There are no data to support this practice. The hypothesis that vascular patients will tolerate a hemoglobin concentration of 9 g/dL was examined., Methods: Ninety-nine patients undergoing elective aortic and infrainguinal arterial reconstructions were prospectively randomized preoperatively to receive transfusions to maintain a hemoglobin level of either 10 g/dL or 9 g/dL., Results: Despite significantly different postoperative hemoglobin levels of 11.0 +/- 1.2 versus 9.8 +/- 1.3 g/dL (P <0.0001), there were no differences in mortality or cardiac morbidity rates or length of hospital stay. There were no differences in hemodynamic parameters. Oxygen delivery was lower in the group with lower hemoglobin levels, but there was no difference in O2 consumption between the groups., Conclusions: A lower hemoglobin concentration was tolerated without adverse clinical outcome. Patients did not compensate for anemia by increased myocardial work, but by increasing O2 extraction in the peripheral tissues.

The ability to clinically assess myocardial contractility in a load-independent fashion facilitates the selection of appropriate inotropes, when needed, during shock resuscitation. Within the framework of the ventricular pressure-volume diagram, the slope of the ventricular end-systolic pressure-volume relationship (expressed as ventricular end-systolic elastance, Ees), has been shown to accurately reflect ventricular inotropic state, and to be insensitive to loading conditions. It has not, however, been widely used at the bedside. Our goal was to evaluate the clinical utility of Ees and the ventricular pressure-volume diagram as bedside methods of hemodynamic assessment. We performed a prospective study of 123 hemodynamic interventions in 100 trauma patients during shock resuscitation in which contractility (Ees), preload (left ventricular end-diastolic volume index), and afterload (effective arterial elastance) were calculated before and after addition of inotropes, fluid bolus, and afterload reduction. Mean values of each variable were compared before and after each type intervention using the paired t test. The ventricular pressure-volume diagram was used to predict changes in the studied variables, and the experimental results were compared with predicted changes. Ees (mmHg/mL/m2) increased significantly with inotropes (4.7 +/- 3.2 to 10 +/- 8.7, p < .0001), but was not affected by clinically significant fluid administration (7.0 +/- 4.7 to 8.3 +/- 8.0, p = .10) or afterload reduction (9.6 +/- 5.2 to 9.2 +/- 4.7, p = .72). Left ventricular end-diastolic volume index (mL/m2) improved with fluid administration (54 +/- 8.9 to 62 +/- 9.8, p < .0001) and effective arterial elastance (mmHg/mL/m2) decreased with afterload reduction (3.3 +/- .9 to 2.6 +/- .7, p < .0001). We conclude that Ees is a load-independent measure of contractility, which is measurable at the bedside. The pressure-volume diagram is a useful method of monitoring hemodynamic changes associated with interventions during shock resuscitation.

Objective: In 1986, data from 25,000 major trauma outcome study patients were used to relate Trauma and Injury Severity Score (TRISS) values to survival probability. The resulting norms have been widely used. Motivated by TRISS limitations, A Severity Characterization of Trauma (ASCOT) was introduced in 1990. The objective of this study was to evaluate and compare TRISS and ASCOT probability predictions using carefully collected and independently reviewed data not used in the development of those norms., Design: This was a prospective data collection for consecutive admissions to four level I trauma centers participating in a major trauma outcome study., Materials and Methods: Data from 14,296 patients admitted to the four study sites between October 1987 through 1989 were used. The indices were evaluated using measures of discrimination (disparity, sensitivity, specificity, misclassification rate, and area under the receiver-operating characteristic curve) and calibration [Hosmer-Lemeshow goodness-of-fit statistic (H-L)]., Measurements and Main Results: For blunt-injured adults, ASCOT has higher sensitivity than TRISS (69.3 vs. 64.3) and meets the criterion for model calibration (H-L statistic < 15.5) needed for accurate z and W scores. The TRISS does not meet the calibration criterion (H-L = 30.7). For adults with penetrating injury, ASCOT has a substantially lower H-L value than TRISS (20.3 vs. 138.4), but neither meets the criterion. Areas under TRISS and ASCOT ROC curves are not significantly different and exceed 0.91 for blunt-injured adults and 0.95 for adults with penetrating injury. For pediatric patients, TRISS and ASCOT sensitivities (near 77%) and areas under receiver-operating characteristic curves (both exceed 0.96) are comparable, and both models satisfy the H-L criterion., Conclusions: In this age of health care decisions influenced by outcome evaluations, ASCOT's more precise description of anatomic injury and its improved calibration with actual outcomes argue for its adoption as the standard method for outcome prediction.

Numerous studies have shown that patients with peripheral and carotid atherosclerosis have a high prevalence of hyperlipidemia, and clinical trials using either angiography or ultrasonography have now demonstrated regression of both femoral and carotid arterial plaque during lipid-lowering therapy. However, whether patients with peripheral and carotid atherosclerosis receive adequate attention to lipid risk factors has not been studied. To evaluate physician recognition and management of hypercholesterolemia in these two patient populations, we reviewed the charts of 80 consecutive patients undergoing revascularization for symptomatic peripheral and carotid occlusive disease at a university medical center between 1990 and 1993. Physician practices were assessed for each patient by noting whether hypercholesterolemia was (1) screened for during the hospitalization and, if present, (2) documented as a problem, (3) managed in-hospital, or (4) given appropriate intervention at discharge. While 73% of patients received some type of lipid case-finding perioperatively, less than one quarter of these were assessed for hyperlipidemia by the physician during the initial history. Moreover, of the 66% of screened patients found to be hypercholesterolemic, only 16% had documentation of the problem, only 24% received in-hospital management, and only 13% received intervention at discharge. These findings suggest that patients with documented peripheral and carotid atherosclerotic vascular disease probably receive inadequate attention to lipid risk factors and indicate the need for greater awareness and management of lipid disorders in these two patient populations by all involved physicians.

Purpose: Since Blaisdell et al. first described axillobifemoral bypass and aortic exclusion to treat patients at high risk with abdominal aortic aneurysms in 1965, this approach has been controversial. To help define the appropriate application of this procedure, the recent experience of the authors was reviewed., Methods: Twenty-six patients underwent operation between March 1980 and August 1992. Mean age was 71 +/- 7 years. Average aneurysm diameter was 7.0 +/- 1.5 cm. Sixty-nine percent of the aneurysms were symptomatic; 21% were suprarenal. All patients had serious comorbid factors. All underwent axillobifemoral bypass with iliac artery ligation; the infrarenal aorta was also ligated in 62%., Results: There were two postoperative deaths (7.7%). One- and two-year survival rates were 59% and 38%, respectively. Three patients died of aneurysm rupture (11.5%); the aorta had not been ligated in two of these patients. The remaining late deaths were due to comorbid conditions. Extraanatomic bypass grafts thrombosed in five patients; no limbs were lost., Conclusions: Axillobifemoral bypass without aortic ligation does not effectively reduce the risk of aneurysm rupture. However, axillobifemoral bypass with aortic ligation is an acceptable treatment for patients with severe medical problems and symptomatic, anatomically complicated, or large abdominal aortic aneurysms. Because the risk of aneurysm rupture is not completely eliminated, this procedure should be reserved for patients with high-risk aneurysms who would not tolerate direct aortic replacement.

The use of outcome indices as a means of evaluating institutional performance for delivery of medical care is at the forefront of federal health policy reforms. Because an enormous number of clinical and financial data are generated by ICU patients, it is inevitable that integrated bedside computers will be necessary to supply the type of information that is being sought by governmental and private insurance agencies involved in assessment of hospital performance. The Health Care Financing Administration already has adopted the APACHE data collection protocols and predictive models for the severity of illness adjustments that were used in assessing the 1986 hospital-specific death rate for acute myocardial infarction, congestive heart failure, stroke, and pneumonia. In our opinion, however, it is unlikely that any single system will be developed that can accurately estimate more than 50% of ICU deaths. The intention of the APACHE III system to include 78 diagnostic categories seems unrealistic. Furthermore, the number of data needed to document outcomes for both low- and high-risk admissions is impractical. We are evaluating APACHE III to determine whether the revisions to the definition for head trauma will represent a significant improvement in predicting outcomes for trauma patients. In the interim, the financial investment in the APACHE III automated bedside data collection system cannot be justified for trauma patients. Neither should it be used in ICUs that admit a large number of trauma patients as a tool for monitoring unit efficiency, guiding triage decisions, allocating staff and ICU beds, identifying risks of iatrogenic or other potential complications, or assessing quality of life, in spite of marketing efforts by the APACHE Corporation. We believe that using any of the APACHE systems for these purposes, at best, is premature, and potentially misrepresents the trauma patient population. Standards for patient classification already are in place for use in making determinations for institutional reimbursement from governmental and insurance agencies. The inequities for certain subgroups of patients, including trauma patients, could create situations in which care is rationed rather than allocated according to a plan that distributes resources efficiently. The APACHE system has several shortcomings and adds little, if anything, to the potential solutions for trauma quality assurance and resource allocation. Nor has the APACHE system established procedures for documenting institutional review of unexpected trauma deaths that would be equivalent, for example, to the type of audit filters applied by the American College of Surgeons in conjunction with the TRISS methodology.(ABSTRACT TRUNCATED AT 400 WORDS)

Objective: To evaluate the use of 250 mL of a 7.5% sodium chloride solution, both with and without added dextran 70, for the prehospital resuscitation of hypotensive trauma patients., Design: Double-blind randomized trial., Setting: Six trauma systems served by helicopter transport., Patients: Injured patients with systolic blood pressures less than 90 mm Hg at any time in the field or during helicopter transport., Interventions: Infusion of study solution, in the field or during transport, followed by conventional isotonic solutions as needed. Solutions studied in four cohorts were as follows: (1) lactated Ringer's; (2) 7.5% sodium chloride (hypertonic saline); (3) 7.5% sodium chloride combined with 6% dextran 70; and (4) 7.5% sodium chloride combined with 12% dextran 70., Main Outcome Measures: Blood pressure response; survival to time of hospital discharge among the treatment groups; and survival compared with that predicted by norms from the Major Trauma Outcome Study (MTOS)., Results: The mean (+/- SD) change in systolic blood pressure on arrival in the emergency department was significantly higher in the hypertonic saline solution group than that in the lactated Ringer's solution group (34 +/- 46 vs 11 +/- 49 mm Hg, P < .03). Overall survival in the four treatment groups was 49%, 60%, 56%, and 45% (not statistically significant). Survival in the hypertonic saline solution group, however, was significantly higher than that predicted by the MTOS norms (60% vs 48%, P < .001). Survival to hospital discharge in patients with baseline Glasgow Coma Scale scores of 8 or less was correlated with treatment group (P < .05 by logistic regression and P < .01 by Cox proportional-hazards analysis; with survival in the hypertonic saline solution group [34%] vs lactated Ringer's solution group [12%])., Conclusions: Prehospital infusion of 250 mL of 7.5% sodium chloride is associated with an increase in blood pressure and an increase in survival to hospital discharge compared with survival predicted by the MTOS norms. Patients with low baseline Glasgow Coma Scale scores seem to benefit the most from 7.5% sodium chloride resuscitation. Hypertonic saline solution without added dextran 70 is as effective as the more expensive solutions that contain dextran 70.

Unlabelled: Setting priorities in the management of patients with suspected injuries to both the head and the abdomen is difficult and depends on the likelihood of different injuries. Eight hundred trauma patients were retrospectively reviewed to determine the likelihood of a surgically correctable cerebral injury. All 800 patients, at the time of initial evaluation, were thought to have potentially correctable injuries to both the head and the abdomen. Of these, 52 had a head injury requiring craniotomy; 40 required a therapeutic celiotomy. Only three patients required both craniotomy and therapeutic celiotomy. There were more cases of delay in therapeutic celiotomy because of negative results of computed tomographic (CT) scanning of the head (13 cases) than there were delays in craniotomy because of nontherapeutic celiotomy (four cases). Need for craniotomy, based on emergency department evaluation, was indicated by the presence of lateralizing neurologic signs. Low Glasgow Coma Scale score, anisocoria, fixed/dilated pupils, loss of consciousness, facial or scalp injuries, and age were of no independent value in predicting the need for craniotomy., Conclusions: Patients with surgically correctable injuries of both the head and the abdomen are rare. In stable patients with altered mental status and potential injuries to both the head and the abdomen, the abdomen is best evaluated first by diagnostic paracentesis. If paracentesis does not return gross blood, CT scanning of the head should be done.(ABSTRACT TRUNCATED AT 250 WORDS)

Small volume infusions of hypertonic saline combined with dextran are very effective in resuscitating animals that have been subjected to hemorrhagic shock, and seem to be effective in resuscitating trauma patients with severe injuries. In this study, the contribution of the dextran component was investigated in a prospective, three-armed, double-blind, randomized trial. Trauma patients transported by ambulance to the hospital with a systolic blood pressure of 90 mm Hg or less were given 250 mL of (1) normal saline (NS); (2) 7.5% NaCl (HS, for hypertonic saline); or (3) 7.5% NaCl in 6% dextran 70 (HSD). Infusion of the study solution was followed by administration of conventional isotonic fluids as the patients' conditions indicated. By predetermined hypothesis, the observed survival rates in the three treatment groups were compared with the predicted survival rates from the TRISS methodology. The 7.5% NaCl solution significantly improved upon the predicted survival for the entire cohort and for high-risk patients when compared with the survival estimates from the TRISS methodology. The addition of a colloid, in the form of 6% dextran 70, did not offer any additional benefit, at least in this setting of rapid urban transport.

The APACHE II system for predicting outcomes in critically ill patients is now being used to evaluate quality of care for patients in surgical intensive care units, including trauma patients. The trauma data, however, on which the APACHE outcomes are based, were derived from only 364 ICU trauma patients. We compared the outcome predictions by APACHE II, TRISS, and a proposed 24-hour ICU point system in 1,000 ICU patients. [table: see text] p less than 0.025 by unpaired t test for predictive power of ICU point system versus APACHE II. Values of more than 15.5 represent poor agreement between the outcomes estimated from the model and the observed outcomes; a low value represents good agreement. The APACHE system significantly overestimated the risk of death in the lower ranges of predicted risk and underestimated the deaths in the higher ranges. Although TRISS was not developed for ICU trauma patients, it tended to perform better than APACHE II in our sample. The 24-hour ICU point system performed well, with accurate agreement between the outcomes estimated from the model and the observed outcomes.

A group of 48 critically injured patients were entered into a prospective, double-blind, placebo-controlled trial to evaluate the efficacy of early infusion of PGE1 for reducing the incidence of severe respiratory failure and mortality. Secondary assessments examined the effects of the PGE1 infusion on plasma mediated suppression of PMN superoxide production and loss of PMN granule enzyme content. The incidence of severe respiratory failure was lower in the PGE1 group--13% versus 32%, but this did not reach significance. The overall morality was equivalent between the two groups--26% (PGE1) versus 28% (placebo). The suppressive activity of the patient plasma was assayed by measurement of normal PMN superoxide production relative to normal control plasma (ratio P:C). The baseline ratio P:C was 62 +/- 5% in the PGE1 group versus 60 +/- 5% in the placebo group. The day 1 plasma samples showed significant reversal of plasma suppressive activity in the PGE1 group--ratio P:C 88 +/- 5% versus 67 +/- 5% in the placebo group (P less than 0.02). In patients who received the full 7 days of infusion, the plasma suppressive activity remained significantly diminished in the PGE1 group--ratio P:C 77 +/- 4% versus 61 +/- 5% (P less than 0.04). The baseline lysozyme content of patient PMN's relative to that of normal control PMNs (ratio P:C) was 119 +/- 14% in the PGE1 group. A significant loss of lysozyme content was observed in the PGE1 group on day 1 of the infusion--ratio P:C 79 +/- 8% (P less than 0.03), and was associated with a reduction in the plasma suppressive activity.(ABSTRACT TRUNCATED AT 250 WORDS)

To determine indications for immediate or delayed amputation of the mangled lower extremity, we reviewed the cases of 80 patients. Vascular, neurologic, bone, and soft-tissue status were reviewed, as were postoperative complications, requirements for mechanical ventilation, fluid balance, delayed amputation, and survival. Although neurologic, bone, and soft-tissue status did influence decisions regarding immediate amputation, they had little to do with delayed loss of limb or life. The circulation, as determined by the presence or absence of a palpable or Doppler-detected pulse, however, was critical. Of six patients in whom salvage was attempted and in whom fluid balances of greater than 3 L were detected in the first 24 hours post-operatively, five eventually required amputation. Salvage should usually be attempted if a distal pulse is present. If no distal pulse is present, the decision for immediate amputation should be based on functional prognosis. In cases in which salvage is attempted, amputation should be performed at 24 hours if the patient's condition, including a markedly positive fluid balance, indicates systemic compromise. In the absence of a distal pulse on presentation, the eventual amputation rate is high.

To evaluate the use of hypertonic saline/dextran solutions in the prehospital resuscitation of severely injured patients, we administered 250 mL of either 7.5% sodium chloride/dextran 70 (HSD) (n = 83) or lactated Ringer's solution (n = 83), followed by conventional isotonic fluids, to 166 trauma patients with systolic blood pressures less than or equal to 100 mm Hg, in a prospective, randomized, double-blinded clinical trial. Patients in the sodium chloride/dextran 70 group required less fluid before hospitalization and arrived in the emergency department with higher systolic blood pressures than patients in the lactated Ringer's solution group. The rate of survival to hospital discharge for the entire cohort was 64% for patients in the sodium chloride/dextran 70 group vs 59% for patients in the lactated Ringer's solution group. The rate of survival to hospital discharge for the patients with severe head injuries was 32% for the sodium chloride/dextran 70 group vs 16% for the lactated Ringer's solution group. Actuarial survival for patients with severe head injuries in the sodium chloride/dextran 70 group compared with patients with severe head injuries in the lactated Ringer's solution group did not quite reach statistical significance. There were no adverse side effects associated with sodium chloride/dextran 70 administration. Administration of small volumes of sodium chloride/dextran 70 before hospitalization increased the blood pressure of severely injured patients more effectively than did lactated Ringer's solution and showed tendencies toward improving survival in the patients with severe head injuries.

In an effort to find the best hypertonic saline-dextran solution (HSD) for prehospital use, 33 chronically catheterized sheep were bled using a fixed pressure shock model (50 mm Hg x 2 hours) and resuscitated with 4 ml/kg of HSD solution (2-minute bolus). In the first set of experiments colloid was varied and sodium chloride was held constant, as 7.5% NaCl was paired with either 0%, 6%, or 12% dextran 70. A dose-response relationship existed, with cardiac output increasing 20% with each sequential dextran 70 concentration. Mean arterial blood pressure was higher in animals that were resuscitated with either the 7.5% NaCl/6% dextran 70 or 7.5% NaCl/12% dextran 70 solution (p less than 0.05). Using the optimal dextran 70 concentration from the first set of experiments (i.e., 12%), solute was varied in a second set of experiments comparing 0.9%, 3.8%, 7.5%, or 10% NaCl/12% dextran 70. Again, dose-response features were demonstrated, as cardiac output increased as a function of NaCl concentration. However, this response plateaued with the 7.5% NaCl concentration and no advantage was obtained by increasing the NaCl concentration to 10%. We conclude that a 4-ml/kg bolus of 7.5% NaCl/12% dextran 70 solution may be a more effective form of therapy than those previously evaluated. This new solution is now being included in our ongoing clinical trials.

We evaluated the potential side effects of rapidly infusing 250 mL of either 7.5% sodium chloride or 7.5% sodium chloride per 6% dextran 70, using lactated Ringer's as the control, to 106 critically injured patients in two prospective double-blinded emergency department trials. Eight patients had a significant hyperchloremic acidemia in association with infusion of the hypertonic solutions, but all eight were moribund before infusion and many factors other than hyperchloremia could have contributed to their acidemia. Other blood chemistry changes that might have been associated with the hypertonic solutions, such as hyperosmolality or hypernatremia, were made insignificant by other factors, such as high blood alcohol levels or concomitant administration of sodium bicarbonate. There were no cases of central pontine myelinolysis; bleeding was not potentiated. There was no difficulty with crossmatching of blood. No anaphylactoid reactions occurred. In a setting of limited volume resuscitation, the solutions are likely to have a favorable risk-to-benefit ratio.

The University of California, Davis, Medical Center introduced the use of nurse practitioners (NPs) to the trauma service in fiscal year 1986-87 to alleviate the increasing burdens placed on the surgical housestaff in their attempt to accommodate the rising patient volume and acuity. The use of NPs was associated with a decrease in average length of stay for the seriously injured patients from 8.10 to 7.05 days while the length of stay for other patients in the hospital remained unchanged. Documentation of quality of care in the medical record increased substantially. For example, discharge summaries that were dictated by the NPs were judged complete in all aspects in at least 95% of sampled records compared with approximately 75% of records that were dictated by the residents. With introduction of the NPs, outpatient clinic waiting times decreased from 41 to 19 minutes. Patient complaints regarding the trauma team decreased from 16 to seven/year. Time saved for the housestaff averaged 352 minutes/day while the NPs were on duty. The NPs were well received by the hospital nurses, hospital quality assurance personnel, and ancillary services. They have proved to be of great value to the patients, the patients' families, the hospital, and the trauma team.

An intraosseous infusion device designed for the prehospital administration of hypertonic saline-dextran solutions was evaluated by resuscitating hemorrhaged conscious sheep. Eight animals underwent 2 hours of hemorrhagic hypotension (50 mm Hg, bled volume = 43 +/- 7 ml/kg). This was followed by the intraosseous infusion of 200 ml (4-5 ml/kg) of 7.5% NaCl-6% dextran 70 into the bone marrow of the sternum. Results were compared to seven control animals (bled volume = 31 +/- 6 ml/kg) resuscitated through a central venous catheter. Despite the small volumes infused, mean arterial blood pressure and cardiac output were rapidly normalized in both groups by 10 minutes post resuscitation (p less than 0.01). Plasma sodium concentration increased an average of 12 mEq/L and plasma volume was rapidly expanded regardless of route. The metabolic acidosis of hemorrhagic shock was rapidly corrected, pulmonary pressures remained normal, and hypoxemia did not occur after intraosseous resuscitation. The device provided safe and rapid vascular access via the sternal bone marrow space. The use of intraosseous infusion of hypertonic saline dextran solutions via the sternal bone marrow may allow prehospital rescuers to consistently incorporate fluid replacement therapy into 'scoop and run' policies by avoiding the time delays associated with failures in IV access.

The use of oral intubation during the resuscitation of seriously injured patients has been discouraged because of the fear that this technique may lead to cervical cord damage. We report a retrospective study of the 18-month experience of an emergency department in which oral intubation was the usual method of airway control for victims of blunt trauma. There were 237 injured patients intubated in the ED; 21 patients (8.9%) had cervical cord or bone injury. There were no patients in whom a neurologic loss followed an airway maneuver. Oral intubation was the definitive airway maneuver in 213 patients. There was no statistically significant difference in the type of definitive airway maneuver used (eg, oral intubation, nasal intubation, or cricothyrotomy-tracheotomy) between patients with cervical injuries and patients without such injuries. The risk of spinal cord injury secondary to oral intubation in the seriously injured patient was low in our population. Selection of the method for definitive airway control should be based primarily on the operator's skills and experience rather than the fear of inflicting cervical cord damage.

Densitometry by video dilution permits regional blood estimation by a modification of the indicator dilution technique originally described by Stewart and Hamilton. Contrast mass is measured from the video fluoroscopic image rather than from dye concentration in blood withdrawn through a sampling catheter. From more than 400 studies, 70 patients who presumably had normal regional flows were selected. Flows in the cerebral, splanchnic, renal, and extremity circulations were determined as a percentage of ascending aortic flow (cardiac output). The regional flow determined by video dilution technique compare well with results of other techniques described in the literature. It is now possible to measure distribution of cardiac output to any major artery during routine angiography, thus providing another determinant of arterial adequacy. These normal values are currently used by the investigators as standards for the evaluation of patients with a variety of vascular diseases.

A standardized test series of contrast medium injections was performed in the iliac and femoral arteries to evaluate the immediate effect of percutaneous transluminal angioplasty. The vasodilator response recorded by video dilution technique was correlated to radiographic anatomy and symptomatology. Discrepancy between anatomic success and clinical relief of symptoms was found in 26 per cent of the dilatations. The severity of disease at the trifurcation was more marked in combination with femoral lesions than with corresponding iliac lesions. Rest pain was a common symptom with femoral lesions and rare with iliac lesions. Resting blood flow increased significantly after femoral dilatation but was unaffected by iliac dilatations. The video dilution technique provided an accurate staging of the severity of obstructive disease, and was an excellent predictor of subsequent symptomatic success or failure of percutaneous transluminal angioplasty.

The video dilution technique for measuring blood flow consists of electronically and mathematically processing video-taped selective arteriograms to measure the flow in selectively catheterized arteries and to express this flow as a fraction of the flow in any reference artery. Flows were measured by video dilution and an electromagnetic flowmeter in ten dogs; the correlations were excellent. Video dilution flows were also measured in 105 patients. The technique is accurate, simple, and adds no risk to routine selective arteriography.

Baboons were subjected to deep hemorrhagic shock by using a membrane potential of -65 mv as an endpoint. They were then resuscitated with either Plasmanate plus their shed blood or Ringer's lactate plus their shed blood. As compared with their own preshock values, the Plasmanate-resuscitated animals accumulated more extravascular lung water than the Ringer's lactate-resuscitated animals. Another group of baboons resuscitated from deep shock demonstrated significant extravasation of albumin on postmortem analysis of lung composition. This increased tendency for extravasation of albumin after shock partially explains why resuscitation with Plasmanate gave no protection against the formation of pulmonary edema. The authors believe that Plasmanate, and probably other colloidal solutions, should be used sparingly in the initial treatment of deep hemorrhagic shock.

A videodensitometric method for estimating relative flow was employed in a patient with a bovine arteriovenous fistula. Analogous arteriovenous communications of different sizes were created in two dogs for comparison. Local and general hemodynamic parameters were measured. The videodensitometric method proved to be highly accurate compared to electromagnetic flow readings and is the method of choice in estimating shunt flow in connection with routine angiography.

A simplified video dilution technique has been developed whereby neither coronary dimensions nor contrast velocity need be measured to obtain coronary blood flow relative to a control flow. In 6 dogs, the distal left anterior descending coronary artery flow was measured by simultaneous electromagnetic flowmeter and video dilution technique. For the 236 paired measurements, the electromagnetic flow ranged from 23 to 196 ml/min for each series. When the first measure of a series was considered the control, the flow ratio difference between electromagnetic and video dilution values had a standard deviation of 12 per cent. When each series was broken into pairs, flow ratio difference between these values had a standard deviation of 10 per cent. Thus, the video dilution technique allows accurate measurement of coronary blood flow relative to a control state, utilizing only the known amount of contrast medium injected and the image from videotape replay of the injection. A patient is presented to illustrate the technique during coronary angiography. Applications include determination of coronary reserve during reactive hyperemia to assess the hemodynamic significance of coronary lesions, and determination of the effects of drugs upon coronary blood flow.

A new videodensitometric method of measuring blood flow in the splanchnic arteries as a fraction of the cardiac output was compared to electromagnetic flow readings in dogs. A previous investigation regarding the accuracy of the method in vitro was extended to prove that the videodensitometric technique was highly accurate also in vivo. The simplicity of the technique suggests that the videodensitometric method could be used to estimate blood flow in splanchnic arteries during routine angiography.

Phosphorus nuclear magnetic resonance (NMR) spectroscopy allows noninvasive monitoring of intracellular high-energy metabolites. In the present study we used topical NMR to monitor intracellular levels of ATP, creatine phosphate (CrP), inorganic phosphate (Pi), and pH in the biceps femoris muscle of rats during hemorrhagic shock and resuscitation. Twelve rats weighing 300-500 gm were anesthetized and bled to a mean arterial pressure (MAP) of 50-55 mm Hg for 90 minutes. Then they were resuscitated with lactated Ringers' until MAP returned to normal or resuscitation fluid equaled four times the shed blood volume. During resuscitation, the rats fell into one of two groups: survivor group (n = 5) which could be successfully resuscitated for 60 minutes or longer; or nonsurvivor group (n = 7) which died during resuscitation. In both groups, ATP levels were maintained during hemorrhage and resuscitation. Intramuscular pH dropped about 0.2 pH units in both groups at the end of hemorrhage; however, pH was restored back toward baseline in the survivor group. CrP levels were lower in the nonsurvivor group at the end of hemorrhage. After resuscitation, CrP returned to nearly baseline levels in the survivor group; in the nonsurvivor group, CrP was further depleted after resuscitation. Pi levels were increased in both groups at the end of hemorrhage, but in the survivor group Pi decreased during the first 15 minutes of resuscitation; in the nonsurvivor group Pi increased further to four times baseline levels. This study demonstrated that topical NMR can quantitate a metabolic deficit in skeletal muscle during hemorrhage and resuscitation. The results show that improvement of intracellular Pi and CrP levels correlated with survival.