Biomedical subjects

K Waxman

Publications and source records attributed to K Waxman.

At least 91 records · Page 5Linked to original sources

PubMed1988

The role of IVP in blunt trauma.

To investigate the role of the IVP, we studied 139 patients with blunt abdominal trauma and hematuria. Multivariate analysis of clinical parameters was utilized in attempt to predict which patients would have abnormal IVP's and which would eventually require genitourinary operation. Thirty-four patients (25%) demonstrated abnormalities on IVP; however, no combination of clinical findings (including degree of hematuria) could reliably predict which patients would have abnormal IVP's. On the other hand, in 90% of the patients, the necessity for genitourinary operation could be reliably predicted based on: presence of blood at the urethral meatus, degree of hematuria, patient age, Injury Severity Score, and number of rib fractures. We conclude that to detect IVP abnormalities, IVP's need to be performed on all blunt trauma patients with hematuria. However, patients likely to have injuries requiring operative repair can be predicted. Those patients unlikely to have genitourinary injury requiring repair, therefore, may have IVP performed on a nonurgent basis.

Abdominal Injuries↗

PubMed1988

Comparative study of cephalexin hydrochloride and cephalexin monohydrate in the treatment of skin and soft tissue infections.

In two prospective, randomized multicenter double-blind studies with a dosage of either 250 mg given four times a day (study A) or 500 mg given two times a day (study B), the comparative efficacy and safety of cephalexin hydrochloride (LY061188; Keftab) and cephalexin monohydrate (Keflex) for treatment of skin and soft tissue infections were determined. In study A, 97 patients received cephalexin hydrochloride and 101 patients received cephalexin monohydrate. In study B, 75 patients received cephalexin hydrochloride and 70 patients received cephalexin monohydrate. Diagnoses included abscesses, cellulitis, wound infections, and infected dermatitis, and were comparable in the different treatment groups. Pathogens were isolated from 82% of patients enrolled; the majority of isolates were of Staphylococcus aureus, Streptococcus pyogenes, other staphylococcal species, and a few gram-negative bacteria. In study A, 68 of 71 (95.7%) evaluable patients who received cephalexin hydrochloride responded satisfactorily; 73 of 81 (90%) patients who received cephalexin monohydrate also responded satisfactorily. In study B, 56 of 58 (96.5%) evaluable patients who received cephalexin hydrochloride responded satisfactorily; 47 of 50 (94%) patients who received cephalexin monohydrate also responded satisfactorily. An adverse clinical event leading to discontinuation of the treatment drug developed in 17 of 343 (4.95%) patients in both studies. No differences were noted between the two drugs. Skin eruptions, pruritus, and mild gastrointestinal symptoms were the common adverse effects. These data suggest that cephalexin hydrochloride, a new formulation of cephalexin, is a safe and effective antimicrobial agent for treatment of a variety of skin and subcutaneous infections in a dosage of either 250 mg four times a day or 500 mg twice a day.

Adult↗

PubMed1988

Prospective trial of supranormal values of survivors as therapeutic goals in high-risk surgical patients.

Survivors of high-risk surgical operations were previously observed to have significantly higher mean CI, DO2, and VO2 than nonsurvivors. The hypothesis was proposed that increased CI and DO2 are circulatory compensations for increased postoperative metabolism. We tested this hypothesis in two series. In series 1, prospectively allocated by services, mortality and morbidity of the control group were significantly greater than those of the protocol group. In series 2, patients who fulfilled previously defined high-risk criteria were preoperatively randomized to one of three monitoring/treatment groups: CVP-control group, PA-control group and PA-protocol group. Postoperative mortalities in the CVP-control and PA-control groups were not statistically significantly different, but PA-protocol group mortality was significantly reduced compared with its control group. The PA-protocol group had reduced complications, duration of hospitalization, duration in ICU, and mechanical ventilation, and reduced costs when the PA catheter was placed preoperatively and used to augment circulatory responses.

Cardiac Output↗

PubMed1987

Effects of portacaval shunt and hepatic artery ligation on liver surface oxygen tension and effective hepatic blood flow.

Liver surface oxygen tension (LSOT) and nutrient hepatic blood flow (NHBF) were measured in rats 1 hr and 1 week after sham operation, portacaval shunt (PCS), and hepatic artery ligation (HAL). LSOT was measured using a heated Clark electrode (37 deg) and was expressed as percentage of rectus muscle O2 tension to correct for changes in systemic oxygenation. Nutrient hepatic blood flow (NHBF) was measured using steady-state, low-dose galactose clearance pharmacokinetics. Acutely, we found a close correlation between LSOT and nutrient hepatic blood flow after both hepatic artery ligation and portacaval shunt. At one week after hepatic artery ligation, LSOT and nutrient hepatic blood flow made parallel increases. However, 1 week after portacaval shunt, LSOT increased while nutrient hepatic blood flow remained reduced. The divergence in these results between the two methods of producing hepatic hypoperfusion, implies that LSOT recovers via a different mechanism after portacaval shunt. Recovery of LSOT at one week probably reflects normalization of hepatic O2 delivery after hepatic artery ligation and impaired oxygen utilization after portacaval shunt.

Animals↗

PubMed1987

Pentoxifylline improves tissue oxygenation following anesthesia and operation.

Pentoxifylline has been shown to increase red blood cell malleability, thus increasing capillary blood flow in a number of disease states. The present study was undertaken to determine whether pentoxifylline might improve tissue oxygenation after anesthesia and during an operation in rats. Rats were anesthetized and divided randomly into pentoxifylline (injected with pentoxifylline) and control (injected with normal saline) groups. Thirty minutes later, midline laparotomy was performed, and surface oxygen tensions and surface temperatures were measured on stomach, liver, cecum, urinary bladder, and anterior abdominal wall. Simultaneously, the mean arterial pressure (MAP) and core temperature were measured. PaO2 was then measured. In the pentoxifylline-treated rats, tissue oxygen tensions were significantly higher than in saline-treated rats. Statistically, there was no significant difference in MAP during these measurements, no difference in either core or organ surface temperatures, and no significant difference in PaO2.

Anesthesia↗

PubMed1987

Value of a conventional approach to the diagnosis of traumatic cardiac contusion after chest injury.

We wanted to evaluate whether current screening techniques effectively determine a patient's need for hospital admission and intensive care monitoring after blunt chest trauma. Consequently, we reviewed 104 consecutive admissions for "blunt chest trauma; rule out cardiac contusion." Neither clinical findings, cardiac enzyme levels, chest x-rays, nor ECGs predicted the high-risk patients who would subsequently develop complications related to myocardial contusion. Since only 23% of the study patients developed such complications, the plurality of study patients did not require admission and monitoring. There is, therefore, a definite need to develop new, accurate screening tests for patients at risk for myocardial contusion complications.

Accidents, Traffic↗

PubMed1987

Laser Doppler velocimetry in critically ill patients.

Cutaneous blood flow may be an indirect measure of circulatory function estimated by continuous, noninvasive laser Doppler velocimetry (LDV). It has been postulated that LDV may be a useful monitor of cardiac output changes. To test this hypothesis, LDV was evaluated in 67 critically ill adult patients with simultaneous measurements of cardiac index (CI) and other physiologic variables. Heated and unheated laser probes were utilized. The results indicate that LDV reflects acute directional changes of CI. Further, with the heated laser probe, the magnitude of acute CI change is reflected. However, there are gradual changes over time of LDV which may occur independently of CI or other monitored variables. Hence, absolute LDV values are not predictive of absolute CI values.

Adult↗

PubMed1987

Early diagnosis of shock due to pericardial tamponade using transcutaneous oxygen monitoring.

The early diagnosis of traumatic pericardial tamponade may be difficult. The transcutaneous oxygen (PtcO2) monitor has been shown to be a useful indicator of low-flow shock. In the case presented, PtcO2 monitoring was the earliest indicator of shock due to pericardial tamponade and led to successful early therapy before other signs of physiologic decompensation were evident. In the management of acutely traumatized patients, PtcO2 monitoring is useful both in identifying patients who are in shock and in helping to guide therapy.

Abdominal Injuries↗

PubMed1987

Protein loss across burn wounds.

One factor contributing to negative nitrogen balance in burned patients is protein loss through the burn wound. There is, however, little information on the amount and type of protein lost by this route. This study was designed to quantitate protein loss through burn wounds. Multiple full- and partial-thickness burns on 29 patients were studied. Sampled burn sites were dried and occlusive sponge dressings (2'' X 2'') were applied and left in place for 1 hour. The central 1 square-inch portion of the dressing was then removed, rinsed in distilled water, and total protein, albumin, and globulin were measured in the water wash. Considerable protein losses were measured. These losses were greatest in the first 3 postburn days, being somewhat greater in full-thickness burns (0.98 +/- 0.82 mg/cm2/hr) compared to partial-thickness burns (0.59 +/- 0.41 mg/cm2/hr) during this period mean +/- SD). Subsequent to the first 3 postburn days, protein loss in all burn types decreased to a relatively steady rate of loss of approximately 0.25 mg/cm2/hr. Based upon these data, average daily protein losses during the first postburn week can be estimated by the following equation: 24-hour protein loss through burn surface (gm) = 1.2 X body surface area (m2) X % burn (%). On subsequent days, protein is lost at approximately half this rate. These data demonstrate significant protein losses through burn wounds greater than recent studies have considered. It is possible that inadequate nutritional replacement of these protein losses is partly responsible for the marked negative nitrogen balance of the early postburn period.

Bandages↗

PubMed1987

Hemodynamic and metabolic changes during and following operation.

During anesthesia and operation, there appears to be a common state wherein oxygen consumption is inadequate to meet intraoperative metabolic requirements. Although there is insufficient information to fully explain this problem, decreased intraoperative levels of cardiac output and oxygen delivery, altered intraoperative oxygen transport at the microcirculatory and cellular levels, and altered delivery of oxidative substrate are possible contributors. Anesthesia and operation thus appear to produce a physiologic pattern similar to other shock states. Postoperative physiologic changes include increased cardiac output and increased oxygen delivery, necessary to support increased oxygen consumption. These postoperative changes may represent compensatory physiologic responses to preoperative and intraoperative oxidative and metabolic deficits. There are also significant energy needs of the healing surgical wound. These additional energy requirements for wound healing add to the degree of increase in metabolism necessary for recovery from operation. The postoperative increase in oxygen consumption appears to be essential to reverse intraoperative deficits, and has been reported to have survival value. Clinically, a major goal of postoperative therapy should thus be to support these necessary physiologic compensations. Titration of postoperative therapy should therefore not be to "normal" physiologic endpoints, but to the supernormal cardiac output and oxygen transport necessary for recovery in postoperative patients.

Energy Metabolism↗

PubMed1987

Mediators of altered perioperative physiology.

Several recent papers have described the development of a new study discipline, psychoneuroimmunology. "The new science begins with the premise that neither the brain nor the immune system can be excluded from any scheme that proposes to account for the onset and course of human disease." This article addresses the concept as it pertains to the perioperative state. Two basic ideas are necessary framework for this discussion, the notion of reflex arcs and a definition of stress.

Adrenal Glands↗

PubMed1987

Postoperative multiple organ failure.

Cellular damage is the pathophysiologic basis for the postoperative multiple organ failure syndrome. This damage may be caused by pre- and intraoperative shock. Postoperative organ failure is manifested when cellular repair does not occur. Three factors may contribute to this progression to multiple organ failure: inadequate resuscitation, malnutrition, and sepsis.

Hemodynamics↗

PubMed1987

Pentoxifylline improves tissue oxygenation after hemorrhagic shock.

This randomized and blinded study was performed to determine whether pentoxifylline significantly improves tissue oxygenation after hemorrhagic shock. Hepatic surface oxygen tension was measured in anesthetized rats before and after hemorrhage. Rats were then randomly assigned to either a placebo group (n = 21) receiving 1 ml of intravenous saline solution or to a treatment group (n = 23) receiving intravenous 25 mg/kg of pentoxifylline in 1 ml of saline solution. Investigators were blinded as to which solution was injected. Five minutes after injection of pentoxifylline, there was significant increase in hepatic surface oxygen tension; this increase persisted throughout 1 hour of observation and was significantly greater than in placebo-treated animals. Further study of the effects of pentoxifylline on tissue perfusion and oxygenation after hemorrhagic shock is warranted.

Animals↗

PubMed1987

Adenomyoma of the papilla of Vater.

An adenomyoma of the papilla of Vater that caused biliary obstruction resulted in an extensive surgical resection because of the clinical and roentgenographic suspicion of carcinoma. Benign neoplasms of the papilla and extrahepatic bile ducts are exceedingly rare, but their recognition is of clinical importance. Histologically, the adenomyoma, characterized by lobules of ducts and ductules with interlacing bundles of smooth muscle, was similar to the adenoleiomyomatous hamartoma of the intestines and to lesions of the gallbladder or extrahepatic ducts known as adenomyomas or adenomyomatous hyperplasia. The presumed rapid recent growth of the present lesion, as roentgenographically documented by the recent onset of dilatation of the common bile duct in an elderly woman, as well as the lack of gallstones or inflammatory disease of the biliary tract, might support the contention that the present lesion was neoplastic. On the other hand, the possibility that the lesion represents a hamartoma or diverticulosis of the saccules of Beale cannot be excluded.

Aged↗

PubMed1986

Diagnosis of traumatic cardiac contusion.

Cardiac contusion following blunt chest trauma remains a diagnostic problem because of a lack of sensitive diagnostic tests. This study evaluated thallous chloride Tl 201 single-photon-emission computed tomography in a series of 48 patients following blunt chest trauma. Of the 48 patients, 23 had normal scans. None of these patients proved to have serious arrhythmias during three days of continuous monitoring. Of 25 patients with abnormal or ambiguous studies, five (20%) developed serious arrhythmias requiring therapy. Single-photon-emission computed tomography scanning thus was sensitive in indicating that group of patients at risk of serious arrhythmias, and may therefore prove to be a useful screening test to determine the need for hospitalization and arrhythmia monitoring following blunt chest trauma.

Accidents, Traffic↗

PubMed1986

Description of a continent jejunal gastrostomy.

A new technique of permanent gastrostomy interposes a vascularized jejunal conduit with an intussuscepted valve between the stomach and abdominal wall, creating a "continent jejunal gastrostomy". In a series of dogs undergoing gastrostomy, the continent jejunal gastrostomy functioned well, with no leakage, and was superior to gastric tube gastrostomy in this regard. Furthermore, there was no evidence of marginal ulceration. A patient who underwent continent jejunal gastrostomy has an excellent one-month result.

Animals↗

PubMed1986

Oxygen delivery and resuscitation.

Modern concepts of oxygen delivery date from the work of Joseph Barcroft, who in 1920 classified deficits of oxygen delivery as "anoxic" when the blood is not filled with oxygen, "anemic" when hemoglobin concentration is low, or "stagnant" when blood flow is inadequate. These three pathologic states may occur singly or in combination, and may be quantitated by the expression: Oxygen delivery = cardiac output X arterial oxygen content Oxygen delivery is an extremely important physiologic concept for resuscitating critically ill patients because tissue availability of oxygen is totally dependent on oxygen delivery. However, other physiologic alterations also can alter tissue use of oxygen, even in the presence of adequate oxygen delivery. These include alterations of oxyhemoglobin dissociation, alterations in microcirculatory blood flow, the presence of carbon monoxide, and mitochondrial dysfunction. The major goal of resuscitation of seriously ill and injured patients is to provide them with sufficient oxygen to meet their metabolic requirements. These needs are significantly increased following shock, injury, and illness. Only by meeting these increased cellular oxygen demands can adequate cellular function be maintained and organ failure avoided.

Cardiac Output↗

PubMed1986

Perfluorocarbons as blood substitutes.

The development of perfluorocarbon (PFC) solutions as clinically useful oxygen-carrying agents has been a slow process because PFC is immiscible in aqueous solutions, including blood. Therefore, it has been necessary to develop emulsions for IV infusions. One such emulsion (fluosol) has been the most extensively studied and has been clinically tested. It has been shown that fluosol can transport oxygen in vivo when very high inspired oxygen concentrations are used and when high arterial oxygen tensions are achieved. Furthermore, it appears that the oxygen dissolved in PFC is very effectively delivered to and used by the tissues. In severely anemic patients, the PFC may deliver a very significant portion of the total consumed oxygen. It has been difficult to prove, however, whether fluosol has been clinically beneficial. It has a limited half-life (13 hours), the amounts infused have been quite limited, and the effect on patient outcome is unclear. Further, a number of adverse effects have been related to fluosol administration, most likely related to the emulsifying agent. PFC solutions thus remain experimental. Their greatest future use may be not as a blood substitute for treatment of anemia, but rather as an agent to improve microcirculatory oxygen delivery for treatment of ischemic tissues (ie, in stroke, myocardial infarction, burns, ischemic extremities). Further development of PFC emulsions is ongoing.

Blood Substitutes↗