Biomedical subjects

W G Cioffi

Publications and source records attributed to W G Cioffi.

125 records · Page 7Linked to original sources

PubMed1989

Relationship of transfusion and infection in a burn population.

The relationship between the number of red blood cell transfusions and major infectious complications was evaluated in 594 thermal injury patients admitted between 1982 and 1986 who had burns over 10% or more of total body surface area and survived more than 10 days. The mean age of this group was 32.9 years, with a mean burn size of 36% of total body surface area; 83% were male. Of the 594 patients, 23.7% died and 38.7% had documented inhalation injury. The mean number of red blood cell transfusions received was 19.7, with a range of 0 to 201. Two hundred fourteen patients (36%) had major infectious complications, defined as pneumonia or invasive burn wound infection. A cross-tabulation of predicted mortality, number of transfusions, and infectious complications revealed a significant positive correlation between transfusion number and infectious complications in patients with predicted mortalities between 10 and 70%. Per cent total burn, patient age, presence of inhalation injury, and number of transfusions were identified by discriminant function analysis as significant variables (p less than 0.05) in discriminating between patients with and without infections (85% accuracy). Logistic regression analysis confirmed the above findings, showing a relationship between the number of transfusions received and infectious morbidity which was independent of age or burn size, but no significant relationship between number of transfusions and mortality.

Adolescent↗

PubMed1988

Fluid resuscitation of infants and children with massive thermal injury.

Age-related limitations of physiologic reserve in burned children make adequacy of intravenous fluid resuscitation critical. To quantify fluid requirements, the medical records of all children admitted to the Army Institute of Surgical Research from 1980 to 1986 whose weight was 25 kilograms or less and burn size was 25% or greater were reviewed to quantify fluid requirements. Forty-three children ranging in age from 1.5-108 months (means 26 +/- 22 m), with 25-89% total body surface burned (TBSB) (means 41.7% +/- 14.6%), met inclusion criteria. The average total volume of fluid received during the first 24 hours was 6.3 +/- 2.2 cc/kg/% TBSB. The net volume of resuscitation fluid, total volume less the calculated maintenance fluid requirements, was 3.91 +/- 2.2 cc/kg/% TBSB. Univariate analysis and linear regression of independent variables including age, weight, per cent full thickness, and inhalation injury revealed each had no significant influence on the volume of resuscitation. We recommend supplying maintenance volume and initiating burn resuscitation at 3 cc/kg/% TBSB.

Body Surface Area↗

PubMed1988

Vascular reactivity following thermal injury.

Major thermal injury is associated with alterations in both pulmonary and systemic vascular resistance. Pulmonary artery hypertension may lead to right heart dysfunction and pulmonary insufficiency. The effect of thermal injury on vascular reactivity is unknown. Increases in circulating vasoactive substances, as well as alterations in vascular smooth muscle receptor activity, have been hypothesized to occur following thermal injury. We have studied aorta and pulmonary artery vascular sensitivity to five agonists in a 35% full-thickness thermal injury rat model. Vascular reactivity was normal to agonists that constrict vascular smooth muscle via receptor-mediated calcium influx. Unresuscitated and resuscitated burn injury resulted in a decrease in peak tension development to prostaglandin F2 alpha (PGF2 alpha) and potassium, agonists whose effects are mediated via membrane depolarization. Fluid resuscitation synchronous with burning did not alter peak tension development in agonists whose actions were mediated via receptor mechanisms. Peak tension development in resuscitated animals to agonists that affect contraction by depolarization remained deficient. To rule out simple blood loss as the etiology for these changes, the experiment was repeated in rats sustaining an acute 25% blood volume loss. Simple hypovolemia induced no changes in aortic or pulmonary vascular sensitivity. We hypothesize that thermal injury may result in a depolarization of vascular smooth muscle membranes altering voltage-dependent calcium channels.

Animals↗

PubMed1986

The effects of burn injury and fluid resuscitation on cardiac function in vitro.

The effects of a 30% full-thickness total body surface area scald burn on in vitro mechanical cardiac function was studied in Sprague-Dawley rats. The findings were a 50% decrease in tension development and velocities of contraction and relaxation, when papillary muscle functions from sham and unresuscitated burned animals were compared. Fluid resuscitation synchronous with burning completely reversed the defects in papillary muscle function. This defect in function was partially transferable to normal muscles incubated in serum from burned rats.

Animals↗

PubMed1986

Renal vascular reactivity in jaundice.

Obstructive jaundice is associated with a predisposition to hypotension and acute renal failure that may be related to changes in renovascular responsiveness, particularly to norepinephrine (NE). This study was undertaken to investigate changes in vascular response to NE and to determine how these changes are related to prostaglandins. Kidneys from bile duct-ligated (BDL) rabbits (n = 5) were perfused with Krebs' solution at 7.65 ml/min, and the response to varying boluses of NE (0.78 to 6.24 micrograms) was measured as changes in perfusion pressure. When compared with sham-operated control kidneys (n = 8), a significantly blunted response was seen at all doses tested. The NE response was further assessed by measuring force development in mounted segments of main renal arteries (MRAs) (n = 8) and interlobar arteries (ILAs) (n = 6) from BDL rabbits and sham-operated controls (MRA, n = 8; ILA, n = 6). The dose-response curves were significantly depressed in both MRAs and ILAs from BDL animals. In addition, MRAs from sham-operated control animals exhibited decreased response to NE after incubation for 1 hour in jaundiced serum. This attenuated response of MRAs to NE was prevented when indomethacin (5 mg/kg) was given to BDL rabbits before death (n = 9) or when 10(-6)mol/L of indomethacin was added to jaundiced serum during incubation (n = 6). These results indicate that obstructive jaundice induces a decreased vascular contractile response in rabbits to NE and that this effect is mediated by prostaglandins.

Acute Kidney Injury↗

PubMed1985

The quantity and function of pulmonary alveolar macrophages after splenectomy and Corynebacterium parvum.

We have previously shown that Corynebacterium parvum (C. parvum), a nonspecific immunomodulator, partially protects splenectomized and nonsplenectomized mice when challenged with aerosolized pneumococci. We report here the effects of both splenectomy and C. parvum on the phagocytic function of the lavageable pulmonary alveolar macrophage (PAM). Groups of young adult male Sprague Dawley rats underwent splenectomy or sham operation 3 weeks before injection of C. parvum 1.5 mg IP (or saline) per animal. One week postinjection PAM's were harvested. The in vitro phagocytic indices (PI) for PAM incubated with tritiated thymidine-labeled S. aureus or Streptococcus pneumoniae, type 14, opsonized with normal rat serum, were determined. Splenectomy had no effect on lung weights, PAM yield, or PAM phagocytic activity. C. parvum administration significantly increased spleen weight in sham-operated animals, but had no effect on lung weights, PAM yield, or phagocytic activity of either control or splenectomized animals. Splenectomy in the adult rat did not induce a phagocytic defect in the PAM and thus the lavageable PAM cannot be considered a significant site of the postsplenectomy defect. Since C. parvum protects animals from respiratory challenge with Streptococcus pneumoniae but does not alter the number or activity of lavageable alveolar macrophages, we hypothesize that C. parvum protection is more likely related to our previous finding of an increased clearance of blood-borne bacteria by the expanded and enhanced reticuloendothelial system.

Animals↗

PubMed1984

Probability of surviving postoperative acute renal failure. Development of a prognostic index.

Sixty-five patients who developed postoperative acute renal failure requiring hemodialysis were retrospectively analyzed to identify variables that could be used to predict outcome. Our aim was to identify patients who would have an unfavorable outcome despite hemodialysis and to identify those factors that might be altered to improve outcome. A linear discriminant function capable of segregating survivors from nonsurvivors in the retrospective analysis was subsequently validated in a prospective fashion using a second patient population. Variables used were age, sex, number of transfusions, interval from onset of acute renal failure to dialysis, type of surgery, preoperative hypotension, and the presence of cardiac failure. Scores were formulated for each patient and then segregated into three groups: patients with no precedence for survival, patients with an intermediate risk of dying, and patients with low risk of dying. Based on the univariant analysis, the interval from onset of acute renal failure to first dialysis and the maximum serum creatinine prior to first dialysis were the only factors that might be altered to change mortality. The prognostic index we have developed enables one to select patients without a chance of survival.

Acute Kidney Injury↗

PubMedDate not supplied

Thromboembolic complications in thermally injured patients.

The frequency of thromboembolic complications in burn patients has been estimated to range from 0.4% to 7%. The clinical significance of these events is often debated and has prompted some centers to adopt the routine prophylactic use of low dose heparin prophylaxis. A 10 year review of 2,103 burn patients treated at this institution was undertaken. Twenty-five (1.2%) patients, with a mean age of 40.0 years and an average burn size of 49.3% total body surface area (TBSA), were identified as having significant pulmonary thromboembolism (PTE). In only 3 (0.14%) patients was the thromboembolism considered to be a cause of death. Nineteen (0.9%) patients, with an average age of 36.7 years and a mean burn size of 48.3% TBSA, developed clinically evident deep venous thrombosis (DVT); however, in only 1 (0.05%) patient did the disease progress to fatal PTE. A review of the literature reveals a 0.6% to 5% incidence of complications related to low dose heparin therapy which includes bleeding, thrombocytopenia, and arterial thrombosis. We feel that the infrequency of clinically significant PTE and DVT in burn patients and the comparable or greater rate of complications associated with heparin prophylaxis mitigate against the routine use of low dose heparin therapy except in patients at high risk for these events.

Adolescent↗

PubMedDate not supplied

An evaluation device for quantifying joint stiffness in the burned hand.

An electronic device capable of measuring finger joint stiffness has been developed and used to evaluate the effects of dynamic flexion splinting on the recovery of joint motion in patients with burned hands. The device locates an angle of primary (greatest) resistance and the reactive torque at that angle for a selected joint. Using the device, four subjects with stiff hands were measured before and after dynamic splinting treatments. During the 3-day treatment period, there were statistically significant differences in the angle of primary resistance (p less than 0.0001) and reactive torque (p less than 0.001). This initial trial suggests that: (1) finger stiffness can be quantified in terms of reactive torque as well as joint excursion, (2) dynamic rubber-band flexion splinting does alter joint condition and allow increased motion, (3) the amount of initial joint stiffness may be an indicator of treatment outcome, and (4) increasing treatment time may not enhance outcome.

Burns↗

PubMedDate not supplied

Intragastric pH monitoring.

Buffering of intragastric pH is an accepted treatment modality for prophylaxis against the development of gastric stress ulcers. This method of prophylaxis is commonly based on the pH value acquired by measurement of gastric aspirate. Recent literature suggests pH measurement techniques that involve gastric aspirate specimens have many flaws. The purpose of this study was to compare gastric pH measurements with the use of a nasogastric sensor, meter system, and pH-sensitive test paper. Fifteen hundred paired serial measurements of intragastric pH were obtained on 19 thermally injured patients (16 men and three women, ages 23 to 79 years, total body surface area burn 25% to 80%). A double-lumen tube containing an antimony/graphite pH sensor incorporated into the tip of the tube was inserted with the use of a standard technique. Each tube was in place an average of 5.7 days (range 1 to 15 days). Patients were randomized into two groups. The first group (six patients) received non-acid-buffering prophylaxis therapy. The second group (13 patients) received standard antacid or antacid/H2 histamine-blocking agent combination prophylaxis therapy. Analysis of the 539 paired measurements for the non-acid-buffering revealed a correlation coefficient of r = 0.532. The 961 measurements from the group receiving gastric acid buffering revealed a correlation coefficient of r = 0.569. Paired t test values for the sample showed a significant difference (18.52, p < 0.0000) between measurement techniques.

Adult↗

PubMedDate not supplied

The risk of pneumonia in thermally injured patients requiring ventilatory support.

The risk of pulmonary infectious complications in critically ill patients requiring ventilatory support is well established. To evaluate the impact of tracheal intubation on the risk of pneumonia, the records of three hundred seventy thermally injured patients (mean age, 37.6 years, mean total body surface area burn, 44.7%) who were admitted during a 6-year interval and required ventilatory support were reviewed. The mean duration of intubation in these patients was 16.6 days, the incidence of pneumonia was 50%, and observed mortality was 37% (137 patients). Though they were significantly older (42.7 vs 35.6 years, p = 0.005) and had a higher frequency of pneumonia (60% vs 46%, p = 0.015) than the 265 patients with inhalation injury, the 105 patients without documented inhalation injury had mean burn size (41.9% vs 45.9%), length of intubation (18.9 vs 15.7 days), postburn day of pneumonia (12.7 vs 10.5 days), and mortality (38.1% vs 36.6%) similar to that group. Actuarial life table analysis considering only pneumonia acquired during ventilatory support was used to evaluate the relation between the risk of pneumonia and duration of ventilatory support. In this cohort of patients with burns, no difference in the risk of pneumonia was observed between patients with and without inhalation injury who required ventilatory support; the hazard of pneumonia was relatively constant during the first 6 weeks of intubation and was similar for all who underwent ventilation.

Adult↗

PubMedDate not supplied

Computer-assisted evaluation of hand and arm function after thermal injury.

Comprehensive care of the burned upper extremity requires accurate and complete evaluation of function, including two-point discrimination, active and passive range of motion, and grip strength. These evaluations, when performed serially during a course of therapy, are time-consuming and manpower-intensive. We tested the utility and accuracy of a commercially available computer-assisted impairment evaluation system when used to automate and standardize measurement of upper-extremity function. The function of 80 upper extremities was evaluated with both the conventional and the computer-assisted methods. The time required to perform a complete examination with each method was recorded, and measurements of grip strength and total active motion made with both methods were compared. Complete upper-extremity evaluation required an average of 20.3 minutes with the computer-assisted method, compared to 62.9 minutes with conventional means. Measurements of extremity function with computer-assisted and conventional methods had correlation coefficients of 0.984 for grip strength and 0.996 for total active motion. The computer-assisted impairment evaluation system was found to be a useful and accurate adjunct in the acute and rehabilitative management of burned upper extremities.

Arm Injuries↗

PubMedDate not supplied

Pressure-controlled ventilation for the long-range aeromedical transport of patients with burns.

Pressure-controlled ventilation is used to treat smoke inhalation injury to achieve adequate oxygenation and ventilation at lower peak inspiratory pressures. A portable pressure-controlled time-cycled transport ventilator permits this modality to be used in the field. We have examined the safety and efficacy of this ventilator for aeromedical transfer of thermally injured patients. Burn flight teams transported 146 intubated patients with thermal injury to the U.S. Army Burn Center with this system. The average extent of burn injury was 40.45% total body surface area with an average full-thickness injury of 25.29% total body surface area. The transport ventilator was used for 57 rotary wing and 89 fixed wing missions. The study group was transported a total of 86,889 miles without in-flight morbidity, mortality, or failure of ventilation. Arterial blood gas analysis at conclusion of flight demonstrated an arterial pH > or = 7.35 in 85% of the patients, an arterial partial pressure of carbon dioxide < or = 45 torr in 97%, and an arterial partial pressure of oxygen > or = 70 torr in 99%. Pressure-controlled ventilation performed by an experienced transport team with this ventilator is safe and effective for the long-range aeromedical transfer of intubated patients with burns.

Adolescent↗

PubMedDate not supplied

CT of blunt trauma bowel and mesenteric injury: typical findings and pitfalls in diagnosis.

Detection of bowel and mesenteric injury can be challenging in patients after blunt abdominal trauma. Early diagnosis and treatment are critical to decrease patient morbidity and mortality. Computed tomography (CT) has become the primary modality for the imaging of these patients. Signs of bowel perforation such as free air and contrast material are virtually pathognomonic. Bowel-wall thickening, free fluid, and mesenteric infiltration may be seen with this type of injury and partial thickness injuries. The authors present and discuss the range of CT findings seen with bowel and mesenteric injuries. Examples of observation and interpretation errors are also provided to highlight pitfalls encountered in the evaluation of abdominopelvic CT scans in patients after blunt trauma.

Abdominal Injuries↗

PubMedDate not supplied

Evaluation of serum visceral protein levels as indicators of nitrogen balance in thermally injured patients.

The use of serum visceral protein concentrations as predictors of nitrogen balance was assessed during the first 4 weeks following thermal injury. The correlation between nitrogen balance and serum albumin was not significant. Statistically significant correlations were found between nitrogen balance and serum prealbumin, retinol-binding protein, and transferrin. However, even the best correlation (retinol-binding protein, r = 0.388) was too weak to permit prediction of nitrogen balance on the basis of the visceral protein concentration. The correlation between change in direction of nitrogen balance and change in direction of protein concentration over time showed all four visceral proteins to be poor predictors of change in nitrogen balance. The efficiency was less than 50% for each visceral protein. Stepwise multiple regression analysis performed to determine which indices were most closely correlated with nitrogen balance showed that a calculation using readily available information (nitrogen intake, postburn day, percent total body surface burned, and age) provided better prediction of nitrogen balance (r = 0.765) than any of the visceral protein concentrations. In view of these findings, measurement of serum visceral protein concentrations to monitor adequacy of nutritional support seems an unwarranted expense in patients with thermal injury.

Blood Proteins↗

PubMedDate not supplied

Accuracy of urinary urea nitrogen for predicting total urinary nitrogen in thermally injured patients.

Estimations of total urinary nitrogen from measured urinary urea nitrogen are commonly used in calculating nitrogen balance. Recently published studies suggest the urinary urea nitrogen/total urinary nitrogen relationship is inconstant and total urinary nitrogen must be directly measured in burned patients. This study addresses the relationship of urinary urea nitrogen to total urinary nitrogen after thermal injury. Two hundred random 24-hour urine collections obtained from 45 thermally injured patients (mean burn size 59 +/- 28%, mean age 40.5 +/- 17.2 years) between 1 and 354 days postburn were analyzed for total urinary nitrogen and urinary urea nitrogen. Regression analysis relating total urinary nitrogen to estimated total urinary nitrogen (urinary urea nitrogen x 1.25) revealed a linear relationship (r = .936, p < .001). The mean urinary urea nitrogen/total urinary nitrogen ratio was 0.77 +/- 0.10 and was not significantly correlated with percent burn, age, or postburn day. Mean nitrogen balance calculated from measured urinary urea nitrogen in these patients was -5.7 g, and that calculated from measured total urinary nitrogen was -6.3 g. This difference, although statistically significant, is of little consequence for clinical use. Contrary to recent reports, we found the urinary urea nitrogen to be sufficiently predictive of total urinary nitrogen for practical application, and do not consider routine total urinary nitrogen measurements necessary for the nutritional care of thermally injured patients.

Adult↗

PubMedDate not supplied

Diagnosis and treatment of smoke inhalation.

Inhalation remains the most frequent and serious comorbid event that occurs in thermally injured patients. A thorough understanding of the pathophysiology enables individualization of therapy and appropriate triage of patients. We summarize our current knowledge of the pathophysiology, diagnosis, and treatment of inhalation injury, with a focus on newer treatment strategies that are evolving secondary to laboratory research.

Airway Obstruction↗