PubMed Health⌕ Search

Biomedical subjects

K G Swan

Publications and source records attributed to K G Swan.

At least 55 records · Page 3Linked to original sources
PubMed1988

Partial versus complete arterial transection, fact versus fancy.

Traditionally, hemorrhage from the partially transected artery exceeds that from its completely divided counterpart. The clinical significance of this distinction is pertinent to the control of the hemorrhage in the field as well as in the operating room. To test the hypothesis the femoral arterial blood flow (Q) of seven anesthetized (pentobarbital, 30 mg/kg, IV) dogs, whose average weight was 19.5 +/- 0.9 kg, was measured before and after partial (25%, 75%) and complete transection of the artery distal to the transducer of an electromagnetic blood flow meter amplifier. Systemic arterial pressure (P) was recorded. Control Q was 72 +/- 14 (S.E.) ml/min, control P was 119 +/- 9 mmHg. Flow increased to 369 +/- 24 ml/min when partial laceration (25% lumenal diameter) was accomplished sharply; this increase was significant (P = 1.7 X 10(-6]. When the arterial division was near completion (75% lumenal transection), Q was 358 +/- 30 ml/min. This value was not significantly different (P = 0.80) from the value that resulted from complete transection of the femoral artery (320 +/- 41 ml/min). Arterial pressure fell transiently (11.5 +/- 1.7, 13.5 +/- 1.6, and 13.9 +/- 2.1 mmHg respectively) as a result of each injury but the apparent differences were not significant (P = 0.25). These observations from canine experimentation indicate that hemorrhage from the partially severed femoral artery is indistinguishable from that which results from its complete transection. In view of these findings in dogs, traditional concepts regarding such injuries in man should be viewed as unproven speculation.

Animals↗
PubMed1987

Use of the Heimlich valve in a compact autotransfusion device.

A compact device which evacuates blood from a hemothorax and facilitates rapid autotransfusion was evaluated in dogs. Experimental hemothorax was established surgically by incising the internal mammary artery through a thoracotomy with the animals under general anesthesia. Postoperatively the blood was drained by one of two methods. In the Heimlich valve group (n = 5), blood was drained by a chest tube through a one-way flutter valve into a collapsible plastic bag. In the Sorenson group (n = 5), blood was drained by a chest tube into the Sorenson Autotransfusion System. Blood from these two groups was then autotransfused. In the control group (n = 5), the drained blood was not autotransfused. Results showed no statistical difference between the two autotransfusion groups in the volume of blood collected, circulating fibrinogen levels, platelet counts, stroma-free hemoglobin levels, prothrombin time, or 51Cr-labeled RBC survival. There was a significant drop in the circulating platelet count, which returned to normal by 24 hours, in both groups of dogs which were autotransfused. We conclude that autotransfusion of blood collected by a compact device which utilizes a Heimlich valve and requires no suction is similar to using the Sorenson Autotransfusion System. It may be safe to use the Heimlich valve to collect blood for autotransfusion in clinical situations, where its qualities of simplicity, portability and a minimum requirement for storage space are desirable.

Animals↗
PubMed1987

Role of antibiotic prophylaxis in surgery for nonperforated appendicitis.

This report examines the efficacy of preoperative antibiotics in cases of nonperforated appendicitis. The charts of 61 patients who had an operative and pathologic diagnosis of acute nonperforated appendicitis were reviewed. Thirty-one patients received preoperative cephalosporins, and in one patient (3.2%) a subsequent wound infection developed. Of 30 patients who did not receive preoperative antibiotics, four (13.2%) patients developed septic complications. The difference in postoperative septic complications between these groups is not statistically significant (P = .3310). Preoperative prophylaxis with cephalosporins in cases of nonperforated appendicitis is not indicated.

Adolescent↗
PubMed1986

Tube thoracostomy and trauma--antibiotics or not?

Controversy persists regarding the use of antibiotics in association with t tube thoracostomy for trauma patients. We conducted a prospective randomized study of patients requiring tube thoracostomy for pneumo- and/or hemothorax complicating blunt or penetrating thoracic trauma in an attempt to assess the efficacy of prophylactic antibiotic therapy. Fifty-eight patients were included in the study. The control group (Group I) included 28 patients who received no antibiotic therapy: the experimental group (Group II) included 30 patients who received cefoxitin (1.0 gm IV q 6 h) commencing before tube thoracostomy and terminating 12 hours after its removal. The incidence of infectious complications (pneumonia and/or empyema) was recorded. Among the patients not receiving antibiotics, eight of 28 (29%) developed infectious chest complications. Of the patients receiving antibiotics, there was one infectious complication (3%). This difference is statistically significant (p = 0.0227). Cultures demonstrated significant conversion from negative to positive both within each group and between groups. The organism most commonly recovered was S. aureus. Our findings strongly suggest that patients requiring tube thoracostomy for trauma, whether blunt or penetrating, should receive the benefit of systemic prophylactic antibiotic therapy.

Adolescent↗
PubMed1986

Surgical management of bleeding esophageal varices. Results with 80 cases.

This report presents results of surgery for bleeding esophageal varices in 80 patients. A prospective randomized study addresses the efficacy of the distal splenorenal shunt (DS) versus the mesocaval shunt (MS) in 50 patients undergoing elective surgery. An additional 30 patients underwent emergency MS for uncontrollable hemorrhage. In the elective series, patients averaged "B" according to Child's Classification. Operative mortality rates were similar (5%). Incidences of encephalopathy were also similar (10%). Those patients undergoing MS experienced an overall operative mortality of 9 per cent, which included emergency shunts (operative mortality 13%). This latter figure is the lowest in the world's literature. Our technique of mesocaval shunting emphasizes short (mean, 3.8-cm) and wide (mean, 21.5-mm) cloth prostheses. Utilizing this approach, we have been able to reduce operative portal venous pressure from a mean (x +/- SE) of 40.1 +/- 1.9 to 13.1 +/- 0.6 cm H2O. The latter value correlated inferior vena caval pressure, 11.8 +/- 0.6 and central venous pressure (recorded by the anesthesiologist) 11.4 +/- 0.5 cm H2O. This is the highest reduction (67%) in portal pressure thus far recorded and reflects our emphasis upon meticulous and extensive dissection of the involved structures. The former minimizes blood loss, which in our hands has been minimal (0.45 +/- 0.18 units per case), reducing the threat of further liver damage; the latter facilitates the "optimal shunt," one which returns portal venous pressure to normal.

Blood Vessel Prosthesis↗
PubMed1985

Hemodynamics of an anastomotic arteriovenous fistula.

Various vascular surgical techniques have been employed to increase both graft patency and limb survival when the prognosis for limb salvage in arteriosclerotic patients is especially poor due to a diseased outflow tract. Ibrahim et al described the creation of an anastomotic arteriovenous fistula in distal tibial bypasses as the reconstructive procedure of choice in severely ischemic extremities unsalvageable by more conventional methods. This study presents the hemodynamics of an anastomotic arteriovenous fistula under such circumstances. Four adult mongrel dogs were anesthesized, and a femoral artery and vein were exposed from the groin to the knee. The femoral artery was ligated in midthigh, and the ligated segment was than bypassed using an umbilical vein graft. The distal anastomosis included an arteriovenous fistula. Flow was measured electromagnetically, and pressure was measured with intravascular catheters attached to strain gauges. The creation of an anastomotic arteriovenous fistula rapidly leads to a reversal of flow in the distal artery, distal arterial hypotension, and distal venous hypertension. Its clinical use in contraindicated as a result of our experimental observations.

Animals↗
PubMed1985

Management of bilateral internal jugular venous injuries.

We report the case of a 16-year-old boy admitted to hospital because of multiple stab wounds. Exploration under general anaesthesia revealed bilateral simultaneous injuries of the internal jugular vein. The management of these injuries is discussed. Optimal treatment requires preservation of at least one internal jugular vein. Both veins may be ligated but this can result in facial oedema and permanent cosmetic defects, and even in death due to cerebral oedema.

Adolescent↗
PubMed1985

Wound ballistics for the civilian surgeon.

The management of gunshot wounds should include the following basic principles: The wound should be assessed by the treating physician in terms of the weapon which caused the injury, its caliber and its muzzle velocity. In addition, the range should be noted and whether the round was copper-jacketed as opposed to hollow-nosed or soft-pointed should be taken into consideration. Knowledge of these ballistic properties will enhance the treating physician's ability to diagnose more appropriately the extent of the damage and influence the therapeutic objectives. In addition, the information obtained will assist in prognosis, which can be related to the patient as well as those concerned with his or her outcome.

Debridement↗
PubMed1985

The Eck-Pavlov connection.

In 1877, N. V. Eck described the surgical creation of a fistula between the inferior vena cava and the portal vein in a dog. At the same time he suggested that this operation might be of use in humans for the treatment of ascites. But it was not until more than 50 years later that A. O. Whipple's report of his experience with Eck's operation ushered in the so-called modern era of the portacaval shunt. While there has been sporadic reports about various phases of Eck's life, most reference books do not even give the date of his death, and some references disagree as to the date of his birth. He has been mistakenly placed among the physiologists rather than the surgeons of Russia, and while quoted as a "brilliant student," he has been accused of being "ill-suited" to his profession by the same source. For his intense interest in other areas such as mining and geology, he is depicted as an erratic man who sought something he probably never found. It is said that for 13 years he was divorced from medicine and surgery, when in fact it was during this period that he performed the only clinical portocaval shunt of his career (and it was successful). Unable to find answers to many questions concerning the 59 years of this man's life in the Western world, a recent trip to Leningrad by the author was informative, interesting, and even surprising. Eck's rarely quoted connection with I. P. Pavlov was more than just an acquaintance, and the famed "Eck-fistula" of the Western world is known as the "Eck-Pavlov shunt" in Leningrad.

Animals↗
PubMed1985

Effects of vasopressin on cardiac output and its distribution in the subhuman primate.

The effects of vasopressin, when administered as intravenous bolus injections and infusions, on cardiac output and the distribution of blood flow to the splanchnic vascular beds were studied in six anesthetized rhesus monkeys. Vasopressin as bolus injections caused dose-dependent decreases in superior mesenteric arterial blood flow. However, small reductions in cardiac output were observed only at the highest doses concomitant with increases in systemic arterial pressure. When vasopressin was infused at the highest dose (5 X 10(-2) units kg-1 min-1) for 10 minutes, cardiac output was unaffected; but sustained reductions in superior mesenteric arterial blood flow and increases in arterial pressure and total peripheral resistance were observed. Infusions of vasopressin (5 X 10(-3) units kg-1 min-1) caused significant and sustained reductions in superior mesenteric arterial blood flow and increases in arterial pressure but no measurable effects on cardiac output or total peripheral resistance. However, there was a significant redistribution of blood flow away from the stomach, small and large intestines, spleen, and pancreas toward the liver (hepatic artery), with no statistically significant change in renal blood flow. On the assumption that comparable responses exist among primates, these data support the clinical use of vasopressin to control gastrointestinal hemorrhage and to offer a probably ideal dose and route of administration.

Animals↗
PubMed1984

A colocutaneous fistula occurring 50 years after a shotgun injury.

Traumatic fistulae of the gastrointestinal tract are usually acute processes which occur at the time of, or shortly after, the injury. Because of its rarity, we report here a case of a colocutaneous fistula that developed 50 years after a shotgun wound of the abdomen.

Abdominal Injuries↗
PubMed1984

Popliteal and infrapopliteal arterial injuries. Differential management and amputation rates.

A 3-year clinical experience is analyzed to define preferred surgical management and amputation rates for popliteal as well as infrapopliteal arterial injuries. Ten patients with popliteal arterial trauma were successfully managed without amputation, however, five of 11 (45%) patients with infrapopliteal arterial trauma required amputation. While essentially all popliteal arterial injuries mandate repair, recommendations for repair or ligation of isolated tibial arterial injuries are based on presence of distal ischemia, the patient's associated injuries, as well as estimated operating time for reconstruction. With injury to two or three infrapopliteal arteries, distal ischemia is usually present and arterial repair indicated, unless there has been severe crush injury, prolonged delay, or extended surgery would jeopardize the patient's life. A management protocol for patients with distal ischemia related to popliteal or infrapopliteal arterial trauma should include prompt surgical intervention, liberal use of fasciotomy, intraoperative arteriography, as well as the selective use of intraluminal shunts.

Adolescent↗
PubMed1983

Traumatic aorto-caval fistula.

Trauma is an unusual cause of fistula formation between the aorta and the inferior vena cava. Two cases of traumatic aorto-caval fistula treated at the New Jersey Medical School affiliated hospitals are presented and the literature on traumatic aorto-caval fistula reviewed. We found 14 previously reported cases. Delayed repair was performed in 12 (86%). Delays ranged from 5 days to 12 years postinjury. Cardiac decompensation, judged either clinically or by cardiomegaly evident on chest X-ray, was present in 75% of the patients undergoing delayed repair. The techniques available for repair and the criteria for utilizing delayed repair are discussed. In young, previously healthy patients, usually with smaller fistulae, we conclude that delayed repair can be used.

Adult↗
PubMed1983

The U.S. M-16 rifle versus the Russian AK-47 rifle. A comparison of terminal ballistics.

The standard U.S. military rifle (M-16) is substantially more destructive than its Russian counterpart (AK-47) when fired at short range into clay blocks, despite the fact that the AK-47 is of larger caliber and fires a much heavier bullet with a kinetic energy (muzzle) 25% greater when compared to the M-16. The decisive factor is the 40% greater muzzle velocity of the M-16.

Forensic Medicine↗