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Biomedical subjects

K W Burchard

Publications and source records attributed to K W Burchard.

At least 37 records · Page 2Linked to original sources

Splenic artery ligation for splenic salvage: clinical experience and immune function.

Documentation of overwhelming post-splenectomy sepsis, characterized by infection from encapsulated organisms, has led to development of surgical techniques for preservation of the injured spleen to maintain splenic clearance of encapsulated, opsonized organisms from the circulation. In this study splenic artery ligation (SAL) was performed as an adjunct to successful splenorrhaphy in 20 adults suffering blunt splenic injury. There were no deaths and no reoperations. Twenty units of blood were transfused in ten patients. Splenic removal of blood-borne opsonized particles was measured as the clearance of anti-Rh-antibody-coated 51Cr-radiolabeled autologous red blood cells from the circulation in five SAL patients and nine normal volunteers. The clearance of opsonized red cells 120 minutes after injection was not different (40 +/- 7% of injected dose in controls, 40 +/- 4% in SAL patients). These results demonstrate that SAL can safely be applied as an adjunct to splenorrhaphy and that SAL does not diminish splenic clearance of opsonized particles from the circulation.

Adolescent↗

Role of gastric colonization in the development of pneumonia in critically ill trauma patients: results of a prospective randomized trial.

Critically ill trauma patients were entered in a prospective, randomized trial to determine the role of gastric colonization in the development of pneumonia. Trauma patients admitted to the SICU were randomized to receive antacids (n = 27), continuous IV cimetidine (n = 32), or sucralfate (n = 30). Quantitative nasogastric tube (NGT) cultures were obtained biweekly and correlated with gastric pH, the incidence of pneumonia, and the incidence of pneumonia caused by an organism previously isolated from the stomach (percentage of gastric source of pneumonia--% GSP). Patients receiving antacids had a significantly greater pH than those receiving cimetidine (5.6 +/- 1.03 vs. 4.7 +/- 1.03; p = 0.006). However, there was no significant difference between the overall incidence of pneumonia, the percentage of NGT isolates greater than 10(6)/ml, or the % GSP. The gastric bacteriology of the three subgroups was nearly identical, with Candida albicans, Enterococci, and beta-hemolytic Streptococci being the most frequently isolated organisms. Gastric growth of organisms preceding their appearance in the blood occurred in 5 of 89 (5.6%) patients. These results suggest that 1) in trauma patients, the incidence of pneumonia is not increased by the use of stress ulcer prophylactic agents that elevate gastric pH; 2) increases in gastric pH progressively increased the number of intragastric bacteria but this did not correlate with an increased incidence of % GSP; and 3) while organisms in the upper intestinal tract may be pathogens for pneumonia, they are uncommonly a source of bacteremia in seriously injured patients.

Adolescent↗

Intraabdominal sepsis: effects on polymorphonuclear leukocyte Fc receptor-mediated phagocytosis.

In vitro studies have shown that phagocytic cells are capable of undergoing activation in response to inflammatory signals and that the activation process is quite complex. A relationship between polymorphonuclear leukocyte (PMN) Fc receptor-mediated phagocytosis and oxidative metabolism has been seen in humans. We have sequentially examined circulating polymorphonuclear leukocytes (PMNs) from a total of 13 postoperative swine with either no sepsis, untreated intraabdominal sepsis, or treated intraabdominal sepsis to determine phagocytic activity over 8 postoperative days (POD). Products of the oxidative burst (i.e., myeloperoxidase) reduced the phagocytic activity of nonseptic swine PMN. Phagocytic activity was augmented by inhibiting the nonseptic swine oxidative burst with 10 mM sodium azide (an inhibitor of myeloperoxidase). In swine with untreated intraabdominal sepsis, PMN Fc receptor-mediated phagocytosis exhibited a biphasic response. An initial (between POD1 and POD4) increase in PMN function was followed by a subsequent (between POD4 and POD8) decrease in PMN function. Partial preservation of phagocytic capability was seen when swine were reexplored on POD4 and had their intraabdominal sepsis treated. These results indicate that (1) as in humans, nonseptic swine PMN Fc receptor-mediated phagocytosis is augmented by inhibition of the PMN respiratory burst; (2) untreated intraabdominal sepsis produces an initial increase and subsequent decrease in PMN Fc receptor-mediated phagocytosis; (3) early treatment of intraabdominal sepsis results in partial restoration of PMN Fc receptor-mediated phagocytosis.

Abdomen↗

Ionized calcium, parathormone, and mortality in critically ill surgical patients.

A prospective study measured ionized calcium and parathormone sequentially at 48- to 72-hour intervals in 25 surgical intensive care unit patients. Twelve patients (48%) died at mean day 40 and median day 26. Levels of ionized calcium, parathormone, blood urea nitrogen, creatinine, albumin, magnesium, and phosphate for patients who lived were compared with levels for patients who died. The incidence of hypotension, renal failure (creatinine greater than or equal to 3.0), and bacteremia, as well as the amount of red cell, crystalloid, and colloid administration for the two groups was compared. Hypotension, bacteremia, red cells, crystalloid, and colloid were no different. On days 1 and 2 ionized calcium levels were significantly lower and parathormone levels significantly higher in nonsurviving patients; this difference persisted through days 3 and 4. Blood urea nitrogen and creatinine levels increased early in nonsurviving patients but renal failure, which occurred in nine nonsurviving patients, did not develop until mean day 14, median day 18. The phosphate level was slightly higher but still within normal range in nonsurviving patients. By days 5 and 6 ionized calcium and parathormone levels were no different in nonsurviving patients, despite there being no improvement in renal function. Magnesium and albumin levels were no different between groups. Ionized calcium levels are lower and parathormone levels higher early in nonsurviving patients. This difference is not readily explained by associated clinical conditions, including renal dysfunction. Although etiology remains unclear, low ionized calcium and elevated parathormone are early predictors of mortality in critically ill surgical patients.

Aged↗

Continuous measurement of atrial volume with an impedance catheter during positive pressure ventilation and volume expansion.

Right atrial volume (RAV) and other hemodynamic parameters were measured in ten anesthetized swine with an impedance catheter in the right atrium during ventilation and increasing levels of positive end-expiratory pressure (PEEP) to determine the effects of PEEP on right atrial dynamics. RAV and cardiac output (CO) decreased progressively during ventilation with 5, 10 and 15 centimeters of water PEEP, whereas central venous pressure and pulmonary capillary wedge pressure increased. Despite this decrease in RAV, atrial ejection fraction increased significantly and active atrial output (AAO equals stroke volume times heart rate) was maintained. Thus, the decrease in CO resulted from a decrease in the passive component of ventricular filling. Compensatory increases in AAO helped to minimize the fall in CO in some swine (r = 0.73, p less than 0.01). Peripheral adenocorticotropin (ACTH) increased from 14.0 +/- 4.5 picograms per milliliter at zero centimeters of water PEEP to 46.8 +/- 18.3 picograms per milliliter at 10 centimeters of water PEEP (p less than 0.05). Volume expansion that restored CO to control levels despite PEEP led to a significant increase in RAV and in passive ventricular filling, as well as a decrease in ACTH to 11.2 +/- 1.5 picograms per milliliter (p less than 0.05). Changes in the ACTH levels correlated with changes in the RAV (r = 0.58, p less than 0.05), but did not correlate with changes in CO, arterial pressure or central venous pressure. The data herein suggest that the decrease in CO with PEEP results from decreased venous return, RAV and passive ventricular filling, whereas a compensatory increase in right atrial contractility helps to maintain CO. Ventilation with PEEP stimulates hormonal secretion that can be terminated by adequate volume expansion.

Adrenocorticotropic Hormone↗

Perforated peptic ulcer. Determinants of morbidity and mortality.

A review of 109 patients with perforated peptic ulcer revealed a sex ratio of 60:49, male:female, with mean age of 67 (76 patients greater than or equal to age 50). Peritoneal cultures were positive in 52 per cent, with the most common organisms streptococci and fungi. Subsequent infectious morbidity with these organisms was rare. Postoperative respiratory and renal failure were associated with intraoperative hypotension (systolic pressure less than 90 mm Hg). Mortality was associated with age greater than 55 and intraoperative hypotension. We conclude that in the 1980s perforated peptic ulcer occurs most frequently in older patients and that acid stomach contents does not ensure sterility, yet subsequent infectious morbidity is rare. Intraoperative hypotension, which occurs especially in patients greater than 55 years, results in significant morbidity and mortality. Attention to preoperative and intraoperative resuscitation is the single most effective therapy for reducing morbidity and mortality from this disease.

Adult↗

A new method of assessing the interpersonal skills of surgeons.

The purpose of this study was to develop a behavioral approach for assessing interpersonal skills of surgeons. Ten Brown University surgery faculty were videotaped (July 87-June 88) in an outpatient setting with an actress portraying a patient with gallbladder disease. Each surgeon's taped behavior was scored at three time intervals by two behavioral scientists using the BUISE method, an interpersonal rating scale for surgeons developed by the authors, and independently scored by a third independent researcher using the Stillman scale. The correlation results demonstrated that the quality of communication competency of these surgeons varied during the three time intervals in which their behavior was evaluated. The Brown University Interpersonal Skill Evaluation (BUISE) instrument was found to be sensitive to the variation of a surgeons' interpersonal skill throughout an entire interview, whereas the Stillman scale correlated with the surgeons' behavior at the end of the interview only.

Clinical Competence↗

Survival after blunt traumatic rupture of the left ventricle.

There have been 11 reported survivors from blunt-trauma-induced right ventricular rupture and only three from left ventricular rupture. We report the fourth case of a survivor of blunt left ventricular rupture. This patient presented with hypotension from both hemorrhage into the left chest and pericardial tamponade. The tamponade was relieved via an emergent left thoracotomy, the bleeding from the rent in the left ventricle was easily controlled, and repair was straightforward.

Adult↗

Hypertonic saline attenuates the hormonal response to injury.

We reported previously in a randomized double-blinded study in 20 postoperative coronary bypass patients that hypertonic saline (1.8% NaCl, HS) provides early hemodynamic benefits, increased osmolality and net negative fluid balance compared to 0.9% NaCl (NS). To investigate the effects of HS on the hormonal response to injury, we measured ACTH, cortisol, angiotensin II (AII), aldosterone, vasopressin (AVP), and atrial natriuretic factor (ANF) in these patients. ACTH and cortisol concentrations increased in the NS group but were suppressed in the HS group (p less than 0.05). Aldosterone increased in NS patients, but was suppressed in HS patients (HS: delta Aldosterone 13.0 +/- 3.0 vs. NS: delta Aldosterone 26.0 +/- 7.0 ng/dl, p less than 0.05). The AII response was suppressed at six and eight hours (p less than 0.05) in patients receiving HS but did not change in patients receiving NS. ANF did not change significantly for either group. The significant increases in AVP were similar in both groups (p less than 0.05), but correlated with increases in osmolality only in the NS group (r = 0.8, p less than 0.009). Other than AVP, HS suppressed the responses of some of the hormones that normally increase in response to injury, relative to NS. Attenuation of the neuroendocrine response and other previously reported effects of HS suggest that HS may be an efficacious solution for resuscitation in the postoperative and postinjury period.

Adrenocorticotropic Hormone↗

Central venous pressure and pulmonary capillary wedge pressure as estimates of left atrial pressure: effects of positive end-expiratory pressure and catheter tip malposition.

We compared CVP and pulmonary capillary wedge pressure (WP) measurements with left atrial pressure (LAP) in postcoronary bypass surgical patients with preserved cardiopulmonary function. Measurements were obtained under normal conditions and conditions likely to induce WP-LAP discrepancies (PEEP and catheter tip malposition). Patients were in both supine and lateral positions; the catheter tip was placed vertically below (tip down; n = 12) or above (tip up; n = 5) the left atrium. Our data showed that both CVP and WP correlated well with LAP at all PEEP levels in the supine and tip down lateral positions. However, in the tip up lateral position, WP overestimated LAP (13.3 +/- 3.4 vs. 8.0 +/- 2 mm Hg; p less than .01) at 20 cm H2O of PEEP, whereas CVP (8.8 +/- 2.1 mm Hg) closely reflected LAP. Thus, by placing the catheter tip vertically below the left atrium in supinely and laterally positioned patients, CVP and WP both produced reliable estimates of LAP despite an acute increase in alveolar pressure. When the pulmonary artery catheter tip was vertically above the left atrium, WP overestimated LAP. Under these conditions, CVP remained a reliable estimate of LAP. We conclude that CVP measurement as an estimate of LAP in this patient population could be used and not ignored. This is true in patients with previously documented good LAP-CVP correlation who are subjected subsequently to conditions which may produce an LAP-WP discrepancy (high PEEP and catheter tip malposition).

Aged↗

Hypertonic saline fluid therapy following surgery: a prospective study.

Successful resuscitation of the injured may be achieved more rapidly and with less fluid using hypertonic crystalloid solutions than with isotonic solutions. This randomized, double-blind study compared 0.9% normal saline (NS) to 1.8% hypertonic saline (HS) in 20 postoperative coronary artery bypass patients suffering uniform injury. Study solutions were administered to maintain physiologic endpoints: heart rate, blood pressure, and pulmonary capillary wedge pressure. The groups were similar with respect to age, body surface area, operative procedure, intraoperative fluid status, and intraoperative and postoperative red cell transfusion requirements. HS patients required 30% less fluid than NS patients and were in negative fluid balance during the study (-1,715 +/- 732 ml/24 hr, HS, vs. +266 +/- 825 ml/24 hr, NS; p less than 0.01). In contrast, NS patients were in positive fluid balance after 8 hours. Moreover, HS patients experienced less chest tube drainage than NS patients (981 +/- 88 ml, HS, vs. 1,700 +/- 285 ml, NS; p less than 0.01). Systemic and pulmonary hemodynamic measurements, oxygen delivery, oxygen consumption, and shunt fraction did not differ between the two groups. Serum sodium and osmolality increased in the HS group and peaked at 12 hours (145.4 +/- 1.4 mEq/L and 308.7 +/- 2.0 mOsm/kg, respectively) and correlated with the volume of HS infused (correlation coefficient = 0.81). No deaths occurred and no complication was attributed the hypertonicity of the solution. We conclude that 1.8% hypertonic saline is a safe alternative to isotonic crystalloid therapy in the fluid management of postoperative patients. Decreased third-space losses may occur with HS as suggested by the lower thoracic losses in the HS group; 1.8% NaCl may be the preferred solution in situations where excess free water administration is not desired, and where interstitial edema is detrimental to function and/or survival.

Clinical Trials as Topic↗

Decompression after gastric surgery. Gastrostomy versus nasogastric tube.

The efficacy and associated morbidity and mortality of gastrostomy (G) versus nasogastric (NG) tube decompression after gastric surgery were analyzed in a review of 100 patients. Age, sex, and risk factors were homogeneously distributed between the two groups, while perforated ulcers and emergency operations were more common in the G group. A gastrostomy did not completely eliminate the need for NG tube decompression in the G group. Postoperative morbidity was similar in the two groups, with the exception of an increased incidence of atelectasis in the elective NG group and increased mortality in the emergency G group. There was also a significant increase in length and cost of hospitalization in the emergency G group compared with emergency NG patients. Gastrostomy does not appear to offer any significant advantage over nasogastric decompression after gastric surgery and should be limited to special cases.

Adult↗

Ketoconazole prevents acute respiratory failure in critically ill surgical patients.

Effective prophylaxis against acute respiratory failure (ARDS) has not been established. This study investigated whether or not ketoconazole could prevent ARDS in critically ill surgical patients. Seventy-one Surgical Intensive Care Unit (SICU) patients without liver dysfunction received either ketoconazole (n = 35), 200 mg daily via the gastrointestinal tract, or placebo (n = 36), for 21 days or until discharge from the SICU, in a prospective, randomized, double-blind study. Patients were monitored clinically for signs of ARDS, defined as all the following: intrapulmonary shunt greater than 15%, a PaO2/FIO2 ratio less than 150, normal central venous, pulmonary capillary wedge, or left atrial pressure, no other cause of hypoxemia, and a consistent chest X-ray. Thirteen patients (18%) developed ARDS with significantly increased mortality versus non-ARDS patients (69% vs. 29%). The incidence of ARDS was decreased among ketoconazole patients compared to placebo (6% vs. 31%; p less than 0.01), as was median SICU stay (7.0 days vs. 15.5 days; p less than 0.05), and median SICU cost (+5,600. vs. +12,400.; p less than 0.05). Mortality is increased with ARDS after trauma and surgery. We conclude that ketoconazole prevents ARDS, shortens SICU stay, and lowers hospital costs.

Adolescent↗

Esophageal pressure monitoring: a practical adjuvant to hemodynamic monitoring with positive end-expiratory pressure.

With positive end-expiratory pressure (PEEP)-induced reduction in cardiac output, measurement of ventricular filling pressure assists in proper therapeutic decision-making. Because PEEP may increase pleural and juxtacardiac pressure, central venous pressure (CVP) and left atrial pressure (LAP) measurements during PEEP may not simply reflect ventricular filling, but rather reflect the sum of intracardiac and extracardiac forces. Monitoring devices placed within the central circulation use saline solution-filled lumens and transducer systems for pressure monitoring. Therefore, any device designed to estimate the extracardiac influence of PEEP on intraluminal monitoring devices would be expected to reflect such changes best when the device is also filled with saline solution. In the present study, esophageal pressure (Pes) was measured with a saline solution-filled balloon-equipped nasogastric tube to estimate the extracardiac influence of PEEP on CVP and LAP. Pes, CVP, LAP, and cardiac index (CI) were measured in 17 patients subjected to 0, 5, 10, 15, 20 cm H2O PEEP. Comparing 0 with 20 cm H2O PEEP, CVP (7 +/- 1.0 mm Hg to 13.4 +/- 1.3 mm Hg), LAP (6.3 +/- 1.1 mm Hg to 11.7 +/- 1.4 mm Hg), and Pes (6.1 +/- 1.4 mm Hg to 12.1 +/- 1.5 mm Hg) all increased significantly as CI fell (2.72 +/- 0.14 L/min/m2 to 2.20 +/- 0.15 L/min/m2).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

Surgical intensive care unit pneumonia.

With use of an objective numerical rating system for the assessment of the presence or absence of pneumonia on a chest x-ray film, 81 patients in the surgical intensive care unit with positive sputum cultures were assigned to either colonization (C; 39 patients) or pneumonia (P; 42 patients) groups. Respiratory failures preceding the first positive sputum culture and hepatic and/or renal failure were more frequent in the P group. Escherichia coli and Pseudomonas species, as well as polymicrobial sputa, were more common in the P group. Positive blood or pleural cultures with the same organism found in the sputum were noted in 10 of 11 P patients and only 3 of 10 C patients. Broad-spectrum antibiotic therapy directed at all sputum pathogens decreased mortality in the P group but not in the C group. We conclude that an objective rating system for chest x-ray diagnosis provides a reasonable method for separating patients with pneumonia from those with colonization. We recommend antibiotic therapy directed at all sputum pathogens in patients in surgical intensive care units. For such therapy to be successful, however, diagnostic criteria must be precise and exclude patients with colonized pathogens.

Bacteria↗

Ketoconazole prevents Candida sepsis in critically ill surgical patients.

We conducted a prospective, randomized, double-blind, placebo-controlled study to determine whether or not ketoconazole could prevent yeast colonization or invasion in critically ill adult surgical patients. Fifty-seven patients in a surgical intensive care unit (SICU) with three or more clinical risk factors for Candida infection were randomized to receive ketoconazole, 200 mg via the gastrointestinal tract daily (27 patients), or placebo (30 patients). Patients with hepatic dysfunction were excluded. The study was continued for 21 days or until one week after discharge from the SICU, whichever was longer. Stool cultures were obtained every three days and other cultures as indicated clinically. Patients were observed for yeast colonization (sputum, urine, stool, or wound) and invasion (fungemia or deep tissue focus). The incidence of Candida colonization was significantly lower in the ketoconazole group than the placebo group. Invasive yeast sepsis developed in five (17%) of the placebo-treated patients and in no patient in the ketoconazole group, a significant difference. Length of stay in the SICU was significantly lower in the ketoconazole group, as were the basic SICU patient charges. Sixty percent of the patients with invasive fungal sepsis died.

Adult↗

Prostaglandin and complement interaction in clinical acute respiratory failure.

This study investigated the interaction of plasma levels of circulating prostaglandins and activated complement in clinical acute respiratory failure (ARDS). Fifty patients at risk for ARDS were followed up for up to ten days. Arterial blood gases and plasma levels of complement components C3a and C5a, thromboxane B2 (TxB), and prostaglandin 6-keto-F1 alpha (PGI) and granulocyte aggregation (GA) were measured daily. Seventeen patients (34%) developed ARDS, with mortality of 41% vs 23% for patients without ARDS. Compared with patients without ARDS, the ARDS group had significantly increased plasma C3a (1,130 +/- 750 vs 636 +/- 368 ng/mL) and granulocyte aggregation (48 +/- 10 vs 17 +/- 4 percentage of the maximum light transmission [% max T]). Plasma C5a, TxB, or PGI did not change significantly with or without ARDS. No measured variable was significantly associated with mortality. Regression analysis revealed significant correlations between GA, TxB, PGI, and arterial oxygenation. Plasma C3a and GA are increased in ARDS, suggesting systemic complement activation. A complex series of interactions between the prostaglandins, complement, and GA appears to be involved in ARDS.

Acute Disease↗