Improved patient survival after cardiac arrest using a cardiopulmonary support system.

A portable cardiopulmonary bypass system that can be rapidly deployed in a nonsurgical setting using nursing staff was used in 38 patients with cardiovascular collapse refractory to ACLS protocol. Percutaneous or cutdown cannulation sites were: femoral vein-femoral artery (n = 18), right internal jugular vein-femoral artery (n = 2), right atrium-ascending aorta (n = 12), or a combination approach (n = 4). Two patients could not be cannulated. Patient diagnoses were pulmonary emboli (n = 3), failed coronary angioplasty (n = 7), myocardial infarction with cardiogenic shock (n = 5), trauma (n = 7), aortic stenosis (n = 2), postcardiotomy deterioration (n = 10), deterioration after cardiac transplantation (n = 2), cardiomyopathy with shock (n = 1), and ruptured ascending aortic dissection (n = 1). Ninety-five percent of patients (36 of 38) were successfully resuscitated to a stable rhythm. Eight diagnostic procedures (coronary angiography, n = 4; pulmonary angiography, n = 3; and aortography, n = 1) were performed while patients were on cardiopulmonary support. Early deaths resulted from massive hemorrhage (n = 8), inability to cannulate (n = 2), and irreversible myocardial injury (n = 10). Sixty-six percent (24 of 36) of patients successfully cannulated underwent conversion to standard cardiopulmonary bypass with attendant operative procedure or placement of ventricular assist device or total artificial heart. Fifty percent (18 of 36) of patients cannulated were successfully weaned from cardiopulmonary support, and 17% (6/36) are long-term survivors.(ABSTRACT TRUNCATED AT 250 WORDS)

The impact of a regionalized trauma system on trauma care in San Diego County.

A review of autopsy reports on traumatic deaths in 1986 was conducted to determine the impact on trauma mortality of the regionalized trauma system instituted in San Diego County in 1984. Determination of preventable death was made by a panel of experts and compared with an identical review of traumatic deaths in 1979, five years before the institution of regionalized trauma care. Of 211 traumatic deaths reviewed from 1986, two (1%) were classified as preventable, compared with 20 of 177 (11.4%) deaths in 1979 (P less than .001). A breakdown of trauma deaths into central nervous system and noncentral nervous system categories revealed the overall decline was in large part a consequence of the decline in non-central nervous system deaths from 16 of 83 in 1979 to one of 62 in 1986 (P less than .005). The decrease in central nervous system-related preventable deaths from four of 94 in 1979 to one of 149 in 1986 (P less than .10) was not statistically significant. Although it is likely the trauma system introduced in 1984 contributed to the decline in preventable death, it is not possible to isolate this variable from other changes that occurred during the interval between studies. A review of trauma deaths over the same time interval in a community with similar demographics but without a trauma system might help determine the relative contribution of the trauma system.

Apparent coagulopathy caused by infusion of shed mediastinal blood and its prevention by washing of the infusate.

We found that reinfusion of shed mediastinal blood (SMB) after a cardiac operation was associated with laboratory evidence of disseminated intravascular coagulation. In view of this, we compared the effect of infusing washed or unwashed SMB on the coagulation profiles and blood use of two serial groups of patients undergoing cardiopulmonary bypass. We found that the results of testing for fibrin degradation products converted from negative to positive in 17 of 20 patients who received unwashed SMB versus 1 of 14 patients who received washed SMB (p less than 0.0001). Other coagulation studies did not reveal disseminated intravascular coagulation in either group, nor were there differences in blood use between the two groups. The unwashed SMB contained high titers of fibrin degradation products (mean reciprocal titer = 354 +/- 161) compared with washed SMB (mean reciprocal titer = 34 +/- 18) (p less than 0.01). Based on the volume of SMB infused, the amount of fibrin degradation products in unwashed SMB was sufficient to account for the positive fibrin degradation product assays after infusion in this group. We conclude that infusion of unwashed SMB may confuse the interpretation of tests for disseminated intravascular coagulation or fibrinolysis. As this could lead to unnecessary blood component use and is preventable by washing before infusion, we recommend that the routine infusion of unwashed SMB no longer be employed.

An autopsy study of traumatic deaths; San Diego County, 1979.

All traumatic deaths in San Diego County were analyzed for the year of 1979. Death certificates, coroner's reports, and autopsy data served as the basis for this review. A total of 177 deaths were studied, of which 94 were associated with CNS injury and 83 were not. Sixteen (20 percent) of the deaths not CNS-associated and four (5 percent) of the CNS-associated deaths were classified as preventable. One hundred seventeen deaths were due to motor vehicle accidents, of which 11 of 35 (31 percent; all not CNS-associated) were deemed preventable. Preventable causes of death included hemorrhage, unrecognized hemopneumothorax, and unrecognized epidural hematoma.

Initial experience with the Rosen incontinence device.

During a 25-month period, beginning in May 1977, 19 patients had Rosen incontinence devices implanted. During the 9 to 34 months of followup 26 additional operations were required for urethral compression balloon leakage, urethral compression balloon aneurysm, tubing kinks, reservoir malfunction and urethral erosion. Currently, 7 devices are in place, 6 of which are functioning and 3 of which have aneurysms of the urethral compression balloon. The 6-month failure rate of the first device was 44 per cent. During the 247 months that the devices were in place the patients were dry for 89 months, and required pad protection for 118 months and condom or an external urethral clamp for 40 months.

Hemodynamic response to exercise in the unanesthetized calf with pulseless arterial flow.

In a chronic unanesthetized calf model with a centrifugal pump inserted from left ventricle to aorta, calves were trained to perform treadmill exercise and undergo hemodynamic measurements. Resting hemodynamic changes with pulseless pumping included increases in cardiac output, aortic pressure, and heart rate, with some decrease in systemic vascular assistance. Treadmill exercise was associated with further increases in cardiac output and heart rate, which progressively increased during the 10 days of observation, with little change in mean aortic pressure. Pump autoregulation responded to the decreased systemic vascular resistance associated with exercise by increasing pump output about 15%, at constant pump rotatory speed. These experiments add further evidence regarding the ability of a centrifugal left ventricular assistance system to support the failing heart and to permit moderate degrees of exercise in the intact unanesthetized calf.

Renin secretion in the chronically perfused pulseless calf. Evidence for failure of stimulation by decreased pulse pressure.

To study the influence of arterial pulse pressure on renin release, a chronic pulseless calf preparation was developed using a centrifugal left ventricular bypass blood pump. After pump implantation and recovery, control measurements of renal vein and arterial plasma renin activity, arterial pressure, and renal artery flow were obtained. The centrifugal bypass pump rate then was increased to capture cardiac output completely, and nine conscious calves were perfused in a nonpulsatile manner (pulse pressure less than 5-10 mm Hg) for 48 hours. Nonpulsatile perfusion was well tolerated and serum sodium, potassium, creatinine, and blood urea nitrogen were unchanged during bypass. Mean arterial pressure remained relatively constant [114 +/- 3 (SE) mm Hg] during bypass, and was not significantly changed from control. Although renal blood flow decreased slightly from control (667 +/- 84 ml/min) during the nonpulsatile perfusion period (555 +/- 73 ml/min), renin secretion did not increase significantly from control (482 +/- 81 ng angiotensin I/ml per hr per min) during the bypass period (531 +/- 99). A diurnal cycle of renin secretin was observed during the pulseless perfusions. These data document the lack of any significant stimulatory influence of decreased pulse pressure on renin secretion in a chronic awake calf model.

Effect of pulseless perfusion on gastrointestinal blood flow and its distribution.

The effect of nonpulsatile (NP) arterial perfusion on gastrointestinal organ blood flow and intraorgan flow distribution was studied in 10 anesthetized (pentobarbital) dogs utilizing the radionuclide-labeled microsphere (15 micrometer) technique. Measurements of flow to the stomach, small intestine, and colon were made during a pulsatile perfusion control period and after 1- and 2-h periods of NP perfusion with a centrifugal left ventricular bypass pump (Medtronic). Total gastric blood flow (0.178 +/- 0.021 ml/min per g) as well as the partitioning of that flow between gastric subsegments such as antrum (17% of total gastric flow), body (83%), and mucosa (73%) was not significantly altered during the 2-h period of NP perfusion (P greater than 0.20). Similarly, flow to the intestine showed significant change during NP perfusion. Under conditions of equivalent hemodynamic states (mean perfusion pressure), nonpulsatile arterial perfusion results in no significant alteration in gastrointestinal blood flow or its intraorgan distribution.

Evaluation of single plane angiography for left ventricular volume in the intact dog.

Technique and errors of quantitative single plane ventriculography (SPV), and the methods of Dodge and Sandler (Dodge et al, 1962; Sandler and Dodge, 1968) and Greene et al (1967) for determining left ventricular (LV) volume by SPV were evaluated in the intact dog. Stroke volume (SV) and cardiac output (Q) by ventriculography were compared with those obtained by the Fick and dye dilution methods, and their combination. The end-diastolic (EDV) and end-systolic volume (ESV) corrected by appropriate regression equations, the SV (SV=EDV - ESV), and the ejection fraction (EF) were: Dodge and Sandler, 2.26 1.35, 0.91 ml/kg, and 0.42; Greene et al, 2.41, 1.50, 0.91 ml/kg, and 0.39. Using adequate methods, accurate correction for x-ray image magnification, and the appropriate regression equations the standard error of LV volume calculation by single plane radiography, due to unavoidable technical inaccuracies, should not exceed 10% for a single measurement and 5% for the average of two or more successive cardiac cycles. The systematic overestimation of LV volume inherent in ventriculography, and caused by the addition of contrast medium, should not exceed 5% of the true value.

Endoplasmic reticulum in rat renal interstitial cells: molecular rearrangement after water deprivation.

Cylindrical bodies in renal interstitial cells of dehydrated rats are confluent with membranes of endoplasmic reticulum. The cylinder walls, composed of helically arranged pentagonal tubules, may represent a molecular rearrangement of the membrane structure. The cylinders may represent a morphologic expression of altered ergastoplasmic function possibly related to the production of concentrated urine.