-
[show abstract]
[hide abstract]
ABSTRACT: Normally, end-tidal CO2 is within 2 mm Hg of arterial PO2 (PaCO2). However, if dead space in the lungs increases owing to shock with poor lung perfusion, the arterial-end tidal PCO2 difference [P(a-ET)CO2] increases. We have found that in severely injured patients, P(a-ET)CO2 of less than 10 mm Hg is associated with survival and P(a-ET)CO2 of greater than 16 mm Hg is usually fatal. Our initial studies suggested that intravenously administered bicarbonate increases P(a-ET)CO2.
This retrospective therapeutic study evaluated the effects of intravenously administered bicarbonate in a cohort of 225 severely acidotic (arterial pH ≤ 7.10) trauma patients who underwent emergency surgery from 1989 through 2011. Patients were divided into groups: early deaths (<48 hours), deaths in the operating room, deaths within 48 hours, and survivors. Winter's formula was defined as PaCO2 = (HCO3) (1.5) + 8 ± 4.
Of the 225 patients, the mean (SD) initial arterial pH was 6.92 (0.16) with HCO3 of 11.0 (3.5) mEq/L. According to the Winter's formula, PaCO2 should have been 24 (4) mm Hg but actually was 50 (14) mm Hg. In 73 patients, the effect of an average of two to eight vials of bicarbonate increased HCO3 from 10.5 (3.1) mEq/L to 16.8 (4.0) mEq/L. In addition, PaCO2 increased from 44 (9) mm Hg to 51 (11) mm Hg and end-tidal CO2 stayed relatively constant (26 [6] to 25 [5]). This resulted in a increase in P(a-ET)CO2 from 17 (9) mm Hg to 24 (13) mm Hg, affecting survival. In the final values after resuscitation, the P(a-ET)CO2 in the 75 patients who survived was 10 (6) mm Hg, while the 103 patients who died in the operating room or within 48 hours of surgery had a P(a-ET)CO2 of 23 (10) mm Hg (p < 0.001).
In severely acidotic, critically injured patients, reducing the PaCO2 to less than 40 mm Hg and decreasing the P(a-ET)CO2 to 10 (6) mm Hg should be attempted, using as little HCO3 therapy as possible. Bicarbonate should be given only if severe acidosis persists despite resuscitation and if PaCO2 levels near those which are appropriate can be obtained.
Therapeutic study, level IV.
The journal of trauma and acute care surgery. 01/2013; 74(1):45-50.
-
[show abstract]
[hide abstract]
ABSTRACT: Abstract Background: Catheter-related blood stream infections (CR-BSIs) are estimated to occur in 80,000 patients in intensive care units (ICUs) each year in the United States. We sought to determine the clinical utility of vascular catheter cultures in critically ill patients with suspected CR-BSI. Methods: We reviewed retrospectively all positive (≥15 colony forming units/roll) vascular catheter tip cultures (CTCs) documented over a four-year period in the ICUs of two hospitals. A CR-BSI was defined as matching positive blood and catheter cultures. The time interval between catheter removal and blood culture was recorded. Results: A total of 1,391 CTCs were obtained, of which 468 (34%) were positive and 143 (31% of the positive cultures) were associated with a diagnosis of CR-BSI. In 133 of these 143 cases (93%), the positive blood culture was obtained before or within 24 h after catheter removal and dictated antibiotic therapy. In only 10 of 143 cases (7%) did catheter removal and culture significantly (>1 day) precede the positive blood culture. In 55% of the CR-BSI cases, the catheter was removed empirically and close to the time of blood culture (-1.3±19.0 h). In the remaining 45%, the catheter was removed clinically (after a blood culture was positive), and this action was more remote in time (23.6±19.4 h; p<0.001 vs. empiric removal). Total microbiology laboratory costs for the CTCs were $75,300, and 600 microbiology technician hours were required. Conclusion: In an ICU patient population, only about one-third of vascular catheter cultures were positive, and only about one-third of the positive CTCs were associated with CR-BSI. Ninety-three percent of all CR-BSIs were identified by bacteremia either before or coinciding with catheter removal, and the results of the blood culture dictated antimicrobial therapy. Because CTCs rarely changed therapy, they may not be appropriate in the management of suspected CR-BSI in the ICU setting.
Surgical Infections 07/2012; 13(4):245-9. · 1.80 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The incidence of vitamin D deficiency in critically ill patients is reported to be up to 50%, with a 3-fold increase in predicted mortality, but limited data exist concerning vitamin D deficiency in critically ill surgical patients.
Sixty-six adult surgical intensive care unit patients who had 25-hydroxyvitamin D serum levels evaluated from January 2010 to February 2011 were prospectively identified. Patients were divided into groups according to vitamin D level (<20 vs ≥20 ng/mL).
Of the 66 patients evaluated, 49 (74%) had vitamin D levels < 20 ng/mL, and 17 (26%) had vitamin D levels ≥ 20 ng/mL. Patients with vitamin D levels < 20 versus ≥ 20 ng/mL had longer lengths of hospital stay. Lengths of intensive care unit stay were clinically longer, although not significant. Infection rates tended to be higher (P = .09), and a higher incidence of sepsis was seen in the patients with vitamin D levels < 20 ng/mL.
Vitamin D levels < 20 ng/mL have a significant impact on length of stay, organ dysfunction, and infection rates. More data are needed on the value of supplementation to improve these outcomes.
American journal of surgery 12/2011; 203(3):379-82; discussion 382. · 2.36 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Pneumonia and other gut-related infectious complications have been associated with the use of histamine 2 (H2) receptor antagonists such as cimetidine in critically ill patients. The mechanism(s) may include acid suppression with resultant effects on the gut flora. Other possibilities include immunologic effects and perturbation of gut barrier function. Recent work has demonstrated the importance of mucus on the gastrointestinal mucosal barrier. We studied the effect of cimetidine on mucus production and mucosal barrier function in vitro.
HT29-MTX, a mucus-producing intestinal epithelial cell line, was used. HT29-MTX cell monolayers were grown to confluence in the presence of cimetidine for 0, 3, or 6 days. Mucus production was quantified by Western Blot analysis and O-linked oligosaccharide chain release and mucin content by enzyme-linked immunosorbent assay. Fluorescein-labeled Escherichia coli (EC) or unlabeled EC were added to quantify bacterial adherence (60-min co-culture) and passage thru HT29-MTX cell monolayers (120-min co-culture), respectively.
Cimetidine treatment decreased mucus/mucin content after 3 or 6 days of treatment. The effect was more profound after 6 days. There was nearly a 2-fold increase in passage of EC across HT29-MTX monolayers after cimetidine treatment.
Cimetidine seems to contribute to gut barrier dysfunction by its effect on mucus production. This study supports the increasing clinical suspicion that routine administration of H2 blockers in critically ill patients may be ill advised.
Surgery 10/2011; 150(4):736-43. · 3.10 Impact Factor
-
Lisa Hall Zimmerman,
James G Tyburski,
Jerry Glowniak,
Rohit Singla,
Todd Lavery,
Michael Nailor,
Jerry Stassinopoulus,
Kaleford Hong,
Surendra Barshikar,
Heather S Dolman,
Alfred E Baylor,
Robert F Wilson
[show abstract]
[hide abstract]
ABSTRACT: Appropriate antibiotic therapy and prompt drainage are essential for optimal results with abdominal abscesses.
In this prospective study, 47 abdominal abscesses from 42 patients over 2 years who had percutaneous drainage were evaluated. Antibiotic concentrations were evaluated from the abscess fluid and correlated with clinical and microbiologic cure.
Only 23% of patients had appropriate antibiotic selection with optimal concentrations for the bacteria recovered. Piperacillin/tazobactam, cefepime, and metronidazole provided adequate concentrations in all except the largest abscesses, whereas fluconazole required higher doses in all abscesses. Vancomycin and ciprofloxacin levels were inadequate in most abscesses. With gram-negative aerobes, the use of appropriate antibiotics resulted in a relatively higher incidence of presumed eradication (100% [4 of 4] vs 75% [9 of 12], P = .26). With ≥ 3 organisms identified, clinical failure was significant (58% vs 13%, P = .01).
For optimal treatment, abdominal abscesses require prompt drainage and properly selected antibiotics at adequate doses. Essential information can be obtained from abscess cultures and their antibiotic concentrations.
American journal of surgery 03/2011; 201(3):348-52; discussion 352. · 2.36 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The incidence of soft tissue infections from antimicrobial-resistant pathogens is increasing. This study evaluated the epidemiology of operatively drained soft tissue abscesses.
This retrospective study evaluated 1,200 consecutive patients from 2002 to 2008 who underwent incision and drainage (I&D) in the main operating room. Patients were excluded for perirectal or hidradenitis infections.
Of 1,200 consecutive cases with an I&D, 1,005 patients had intraoperative cultures. The 1,817 positive isolates included gram-positive aerobes (1,180 [65%]), gram-negative aerobes (207 [11%]), anaerobes (416 [23%]), and fungi (14 [1%]). The most prevalent organism was Staphylococcus aureus, 30% (536), with 80% (431) being methicillin-resistant S aureus (MRSA). MRSA was the predominant organism in all except the breast abscesses. Anaerobes were identified primarily in the breast in diabetics, and in trunk and extremity abscesses in intravenous drug users. The most frequently prescribed empiric antibiotic was ampicillin/sulbactam (66%). The initial empiric antibiotic did not cover MRSA (82%; P < .001), resistant gram-negative aerobes (24%), and anaerobes (26%).
Gram-positive aerobes plus anaerobes represented approximately 80% of the pathogens in our series, with the anaerobic rates being underestimated. Empiric antibiotics should cover MRSA and anaerobes in patients with superficial abscesses drained operatively.
Surgery 10/2009; 146(4):794-8; discussion 798-800. · 3.10 Impact Factor
-
Lisa Hall Zimmerman
[show abstract]
[hide abstract]
ABSTRACT: Pharmacists who practice in the critical care setting require a solid background on the causes and consequences of bleeding, as well as the mechanisms of hemostasis. This article provides an overview of these topics. Bleeding and outcomes as a result of surgery and trauma, from medical and pharmacologic causes, and in obstetrics and gynecology are discussed. Patients with brain trauma, those with inherited and acquired bleeding disorders, and patients undergoing therapeutic anticoagulation are addressed, as these are populations at special risk for severe bleeding. Bleeding events as a result of hypothermia, acidosis, and disseminated intravascular coagulation are also discussed, as is the pathophysiology of massive blood loss. Traditional and newer cell-based models of coagulation mechanisms are described and compared. Application of this information in pharmacy practice will help ensure that therapies to manage and arrest blood loss are used appropriately in a wide variety of clinical scenarios.
Pharmacotherapy 10/2007; 27(9 Pt 2):45S-56S. · 2.90 Impact Factor
