Kenneth W. Burchard

Fungal infection in surgical patients

Invasive fungal infections have become a major source of morbidity and mortality in the modern surgical intensive care unit. Patients at risk for invasion and dissemination are common, and are not as ill as thought previously. Severity of illness (APACHE II score > 10, ventilator use for >48 hours), antibiotics, central venous lines, total parenteral nutrition, burns, and immunosuppression are the most common risk factors. Recognition of these risk factors should arouse a high index of suspicion for the diagnosis of invasion or dissemination. Unfortunately, laboratory tests alone lack sensitivity and specificity. Therefore, the diagnosis of invasion and dissemination in the majority of cases requires the acquisition and proper interpretation of clinical evidence. Once the diagnosis is made, early systemic treatment is warranted. Reported toxicity and efficacy supports the use of fluconazole for most patients with invasive fungal infections. However, for the most critically ill patients amphotericin B remains the treatment of choice.

Peptic Ulcer/Stricture After Gastric Bypass: A Comparison of Technique and Acid Suppression Variables

Background: Masons original animal experiments on the gastric bypass (GBP) showed little acid production in the gastric pouch, a finding confirmed in humans. Despite this, GBP in humans is associated with an incidence of ulcer/stricture (U/S) at the gastrojejunostomy of 3 to 20%, with both acid secretion and staple-line dehiscence considered important risk factors or etiologies. Our series of GBP patients was reviewed to determine what technical or management factors, if any, were associated with U/S. Methods: All patients undergoing first time GBP at Dartmouth-Hitchcock Medical Center by one surgeon from June 1991 until June 2000 were reviewed. The incidence of U/S as confirmed on upper endoscopy was determined by retrospective chart review. The technique of surgery, frequency of acid suppressive therapy at discharge, postoperative day of U/S diagnosis by endoscopy, length of follow-up with a member of the multidisciplinary bariatric team, and incidence of staple-line dehiscence were tabulated. Results: 158 patients (72% female, mean BMI 53, mean age 42) underwent GBP.Two gastric stapling methods were used to create the gastric pouch: 4-rows (136 patients) and 8-rows (22 patients). No other technical feature was adjusted in the series. The two patient groups were similar in gender, age, and BMI. Acid suppressive therapy at the time of discharge was similar in each group with U/S (4-rows 64% and 8-rows 50%, p=0.5). U/S developed in 12 (55%) of the 8-row group and in 14 (10%) of the 4-row group (p < 0.001). U/S typically occurred within the first 2 months postoperatively (mean 48 days, SD 40). No patients in our series developed a staple-line dehiscence. Conclusion: U/S occur in the first few months following GBP.Twice the number of gastric staple-lines is associated with over five times the incidence of U/S, whereas post-discharge acid suppressive therapy is not predictive of U/S. Thus, a technique performed to decrease the risk of staple-line breakdown was associated with a much higher incidence of U/S. Staple-line dehiscence is not the etiology of this condition.Therefore, U/S after GBP does not appear to be explained by acid injury. We speculate that local, tissue injury related factors may be more responsible, a speculation that invokes a novel pathophysiologic mechanism for U/S formation following gastrojejunostomy.

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

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.

Ionized Calcium, Parathormone, and Mortality in Critically 111 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.

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.

Surgical Perspective on Invasive Candida Infections

Abstract. Invasive and disseminatedCandida infections have become a major source of morbidity and mortality in the modern surgical intensive care unit. The most common risks for invasion and dissemination are the use of antibiotics, central venous lines, total parenteral nutrition, burns, immunosuppression, and other markers for severity of illness (APACHE > 10, ventilatory use for > 48 hours). Data suggest that colonization can be a late predictor of invasive disease in today’s critically ill surgical patient and that prophylaxis or early treatment in high risk patients is warranted, particularly before invasive/disseminated disease becomes life-threatening. When advanced disease is present, the diagnosis of invasive or disseminatedCandida infection is often prompted by clinical suspicion and supported by consistent clinical data; laboratory tests alone lack sufficient sensitivity and specificity to direct therapeutic decision-making. Once the diagnosis of invasive or disseminatedCandida infection is ascertained, early systemic treatment, along with treatment of localized infection, is as fundamental as with any other serious infectious disease. Reported toxicity and efficacy supports the use of fluconazole for most patients with invasive/disseminated Candida infections. For the most critically ill surgical patient amphotericin B remains the treatment of choice. Prophylaxis and early treatment strategies with minimally toxic agents may diminish the need to use more toxic therapy in the most severely ill patients.

Trendelenburg versus Pasg Application—hemodynamic Response in Man

Diminished venous return is the primary determinant of reduced cardiac output in hemorrhagic hypoperfusion. In this study the hemodynamic response of two therapies commonly employed to increase venous return in hemorrhagic hypoperfusion--pneumatic antishock garment (PASG) application and Trendelenburg (TREND) positioning--were compared in normovolemic man. Five patients had PASG pressure of 20 mm Hg compared with 10 degrees Trendelenburg, eight patients had 20 and 40 mm Hg PASG application compared with 10 degrees Trendelenburg. PASG application at both 20 and 40 mm Hg resulted in a significant increase in CVP (11.1 +/- 1.9 baseline to 16.0 +/- 2.7 PASG 40; p less than 0.01) left atrial pressure (LAP) (10.1 +/- 1.3 baseline to 14.4 +/- 1.8 PASG 20; p less than 0.01) pulmonary capillary wedge pressure (PCWP) (11.6 +/- 2.0 baseline to 16.8 +/- 3.4 PASG 40; p less than 0.01) and esophageal pressure (Pes) (5.0 +/- 0.8 baseline to 8.6 +/- 0.9 PASG 40; p less than 0.01). However, transmural right and left atrial pressure (RATP, LATP) and cardiac index (CI) were unchanged. Ten degrees of Trendelenburg resulted in no increase in CVP, PCWP, RATP, or LATP, but CI (2.67 +/- 0.07 baseline to 2.82 +/- 0.1 TREND; p less than 0.01) was significantly increased. Systemic vascular resistance index (570 +/- 46 TREND vs. 668 +/- 53 PASG 40; p less than 0.01) was significantly less in Trendelenburg compared to PASG at 40 mm Hg. The data demonstrate that elevation in CVP, LAP, and PCWP following PASG application is secondary to an increase in intrathoracic pressure (as measured by Pes).(ABSTRACT TRUNCATED AT 250 WORDS)

A Surgery Oral Examination: Interrater Agreement and the Influence of Rater Characteristics.

BACKGROUND. Poor interrater reliability is a common objection to the use of oral examinations. METHOD. In 1990 the authors measured the agreement of 140 U.S. and Canadian surgical raters and the influences, if any, of age, years in practice, and experience as an examiner on individual oral examination scores. Eight actor examinees memorized transcripts of actual oral examinations and were videotaped using a single examiner. Examinee verbal style, dress, content of answers, and gender were purposefully adjusted. A repeated-measures analysis of variance was used for data analysis. RESULTS. Three aspects of examinee performance influenced scores (verbal style, dress, and content of answers). No rater characteristic significantly affected scores. Raters showed high agreement (86%) when rating “good” performances but less agreement (67%) when rating “poor” performances. CONCLUSION. The oral examination scores were not influenced by rater selection. The raters ranked good performances more consistently than poor performances. Therefore, more than one examiner appears necessary to confirm a poor performance during an examination.

Hypercalcemia in critically ill surgical patients.

Critical surgical illness, commonly accompanied by shock, sepsis, multiple transfusions, and renal failure, is usually associated with low total calcium and/or low or normal ionized calcium. A seminal case of hypercalcemia in a surgical intensive care unit (SICU) patient prompted the review of 100 patients with longer than average SICU days (greater than 12) to determine the incidence, associated factors, and possible etiologies of this condition. Ten patients had elevated measured, and five others had elevated calculated, ionized calcium (5.9 +/- 0.25 mg%), an incidence of 15%. Compared to the 85 patients who did not develop hypercalcemia, this population had a significantly higher frequency of the following: renal failure, dialysis, total parenteral nutrition (TPN) usage greater than 21 days, bacteremic days greater than 1, transfusions greater than 24 units, shock greater than 1 day, SICU days greater than 36, and antibiotics used greater than 7. In addition, this group had significantly more days of hypocalcemia early in their hospital course. There was no difference in sex, age, mortality, or incidence of respiratory failure. Two patients studied in depth had renal failure requiring dialysis and no malignancy, milk-alkali syndrome, hyperthyroidism, or hypoadrenalism. Parathormone (PTH) concentrations were high normal or elevated (N terminal 20 and 21 pg/ml; C terminal 130 microliters Eq/ml and 1009 pg/ml) at the time of elevated calcium (total 9.2 to 14.6 mg%; ionized 4.9 to 8.2 mg%). Immobilization does not increase PTH. In renal failure, PTH elevation is a consequence of hypocalcemia rather than hypercalcemia. Moreover, five patients did not have renal failure. Shock, sepsis, and multiple transfusions containing citrate may lower total and/or ionized calcium and thus stimulate PTH secretion. Whatever the mechanism, approximately 15% of critically ill surgical patients develop hypercalcemia, which may represent a new form of hyperparathyroidism.

Secondary Overtriage: The Burden of Unnecessary Interfacility Transfers in a Rural Trauma System

IMPORTANCE Unnecessary interfacility transfer of minimally injured patients to a level I trauma center (secondary overtriage) can cause inefficient use of resources and personnel within a regional trauma system. OBJECTIVE To describe the burden of secondary overtriage in a rural trauma system with a single level I trauma center. DESIGN Retrospective analysis of institutional trauma registry data. SETTING Dartmouth Hitchcock Medical Center, a rural level I trauma center. PATIENTS A total of 7793 injured patients evaluated by the trauma service at Dartmouth Hitchcock Medical Center from January 1, 2007, to December 31, 2011. EXPOSURE Evaluation by the trauma service. MAIN OUTCOMES AND MEASURES Patients transferred from another hospital to Dartmouth Hitchcock Medical Center who did not require an operation, had an Injury Severity Score lower than 15, and were discharged alive within 48 hours of admission. RESULTS Of the 7793 evaluated patients, 4796 (62%) were transferred from other facilities. When compared with scene calls (n = 2997), transferred patients had a similar median Injury Severity Score of 9, but 24% of transferred adult patients and 49% of transferred pediatric patients met our definition of secondary overtriage. The overtriaged patients were most likely to have injuries of the head and neck (56%), followed by skin and soft-tissue injuries (41%). Seventy-two unique institutions transferred trauma patients to Dartmouth Hitchcock Medical Center, but 36% of the overtriaged patients were from 5 institutions. CONCLUSIONS AND RELEVANCE The incidence of secondary overtriage in our rural trauma center is 26%, with head and neck injuries being the most common reason for transfer. Costs for transportation and additional evaluation for such a significant percentage of patients has important resource utilization implications. Effective regionalization of rural trauma care should include methods to limit secondary overtriage.