Author Archives: Hannah

Risk of acute kidney injury in patients on vancomycin

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One discussion this week included the use of vancomycin in the setting of acute kidney injury (AKI).

Reference: Navalkele B, et al. Risk of acute kidney injury in patients on concomitant vancomycin and piperacillin-tazobactam compared to those on vancomycin and cefepime. Clinical Infectious Diseases. 2017 Jan 15;64(2):116-123. doi:10.1093/cid/ciw709.

Summary: In a retrospective, matched, cohort study of 558 patients, Navlkele et al (2017) compared the incidence of AKI among patients receiving combination therapy with vancomycin + piperacillin-tazobactam (VPT) to a matched group receiving vancomycin + cefepime (VC).

AKI rates were significantly higher in the VPT group than the VC group (81/279 [29%] vs 31/279 [11%]). In multivariate analysis, therapy with VPT was an independent predictor for AKI (hazard ratio = 4.27; 95% confidence interval, 2.73-6.68). Among patients who developed AKI, the median onset was more rapid in the VPT group compared to the VC group (3 vs 5 days P =< .0001).

Types of perirectal abscesses

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One discussion this week involved perirectal abscesses.

Reference: Calandrella C, La Gamma N. Abscess, Perirectal. In StatPearls [NCBI Bookshelf]. Last updated: 2018 Oct 27.

Summary: Although often thought of as the same, perianal abscess and perirectal abscesses differ in both complexity and care options. Except for perianal abscess which can be simply incised and drained as definitive care, all others usually require intravenous antibiotics, surgical evaluation, and drainage. A majority of abscesses are diagnosed clinically based on skin findings and palpitation of the affected area alone, but some require advanced imaging to determine the extent of infiltration.

A perirectal abscess can be further divided into a category based on anatomical location: ischiorectal abscess, intersphincteric abscess, and supralevator abscess. Given the variability in location and severity of the abscess, it is important to consider the presence of fistulas or tracts which may contribute to the spread of the infection. Perianal abscesses are the most common type, followed by ischiorectal, and intersphincteric abscesses.

Alternatively, the Park’s classification system which groups the fistulas into 4 types based on the course of the fistula and the relationship to the anal sphincters.

  • Intersphincteric (70%): Between the internal and external sphincters
  • Trans-sphincteric (25%): Extends thru the external sphincter into the ischiorectal fossa
  • Suprasphincteric (5%): Lasses from the rectum to the skin through the levator ani
  • Extrasphincteric (1%): Extends from the intersphincteric plane through the puborectalis

EPIDEMIOLOGY: The incidence of anorectal abscesses is 1:10,000, resulting in approximately 68,000 to 96,000 cases in the United States per year with a male prevalence of 3:1 during the third and fourth decades of life. The condition is seen more in the summer and spring months. Although often a concern of the patient, data does not support that there is an increased risk from hygiene, anal-receptive intercourse, diabetes, obesity, race, or altered bowel habits.

Risk factors for aspiration in community-acquired pneumonia

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One discussion this week involved the risk factors for aspiration in community-acquired pneumonia (CAP).

References: Komiya K, et al. Prognostic implications of aspiration pneumonia in patients with community acquired pneumonia: A systematic review with meta analysis. Scientific Reports. 2016 Dec7;6:38097. doi: 10.1038/srep38097

Taylor JK et al. Risk factors for aspiration in community-acquired pneumonia: analysis of a hospitalized UK cohort. American Journal of Medicine. 2013 Nov;126(11):995-1001. doi:10.1016/j.amjmed.2013.07.012.

Summary: Aspiration pneumonia can be defined as pneumonia in patients who have aspiration risk. Komiya et al (2016) list the following as risk factors for aspiration:

  • impaired consciousness
  • chronic neurological disease
  • weakness
  • swallowing difficulties
  • esophageal dysfunction or mechanical obstruction
  • aspiration witnessed during eating or vomiting
  • sedation

Overt aspiration is generally not witnessed, and aspiration alone cannot fully explain the development of pneumonia. Most healthy subjects passively aspirate oropharyngeal secretions during night, but their cough reflex, mucociliary clearance, and immune system usually prevents the development of pneumonia (Komiya et al, 2016).

In their observational study of 1348 patients with CAP, Taylor et al (2013), while also listing the factors above, noted these additional risk factors:

  • older (above 60-84, median of 74 years)
  • comorbidities of chronic liver disease, congestive heart failure, and stroke

Komiya et al’s (2016) systematic review findings suggest that aspiration risk is associated with greater in-hospital and 30-day mortality in subjects with CAP except, perhaps, in the ICU setting. Although there are insufficient data to perform a meta-analysis on long-term mortality, recurrent pneumonia, and hospital readmission, the few reported studies suggest that aspiration pneumonia is also associated with these outcomes.

 

Chemical VTE prophylaxis after cardiovascular surgery: how soon is too soon?

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One discussion this week involved how soon after cardiovascular surgery to restart VTE prophylaxis heparin.

Reference: Ho KM, Bham E, Pavey W. Incidence of venous thromboembolism and benefits and risks of thromboprophylaxis after cardiac surgery: A systematic review and meta-analysis. Journal of the American Heart Association. 2015 Oct 26;4(10):e002652. doi: 10.1161/JAHA.115.002652.

Summary: A systematic review and meta-analysis (Ho et al, 2015) found no evidence to support the notion that use of low-dose UFH or LMWH for VTE prophylaxis would increase risk of cardiac tamponade, pericardial effusion, or bleeding after cardiac surgery. Though these complications are not rare after surgery, whether low-dose UFH or LMWH would substantially increase such risks remains scientifically unproven (p.21).

Bleeding after cardiac surgery is mainly related to systemic overanticoagulation or concurrent use of systemic anticoagulation and platelet agents. The AHA document concludes that, unless proven otherwise by adequately powered RCTs, initiating low-dose UFH or LMWH as soon as possible or on postoperative day 1 after cardiac surgery for patients who have no active bleeding is highly recommended, especially if they have multiple risk factors for VTE.

Additional Reading: Agnelli G. Prevention of venous thromboembolism in surgical patients. Circulation. 2004;110(24, supp1):IV-4-IV-12. doi: 10.1161/01.CIR.0000150639.98514.6c

 

Effectiveness of pyloric exclusion (PEX) in treating duodenal trauma

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One discussion this week involved the use of pyloric exclusion (PEX) for management of severe duodenal injuries.

References: DuBose JJ, et al. Pyloric exclusion in the treatment of severe duodenal injuries: results from the National Trauma Data Bank. The American Surgeon. 2008 Oct;74(10):925-929.

Malhotra A, et al. Western Trauma Assoication Critical Decisions in Trauma: Diagnosis and management of duodenal injuries. Journal of Trauma and Acute Care Surgery. 2015 Dec;79(6):1096-1101. doi: 10.1097/TA.0000000000000870

Summary: Using the American College of Surgeons National Trauma Data Bank (v 5.0), DuBose et al (2008) evaluated adult patients with severe duodenal injuries [AAST Grade > or = 3] undergoing primary repair only or repair with PEX within 24 hours of admission.  Of the 147 patients, 28 (19.0%) underwent PEX [15.9% (11/69) Grade III vs 34.0% (17/50) Grade IV-V]. Their main findings were:

  • PEX was associated with a longer mean hospital stay (32.2 vs 22.2 days, P = 0.003).
  • PEX was not associated with a mortality benefit.
  • There was a trend toward increased development of septic abdominal complications (intra-abdominal abscess, wound infection, or dehiscence) with PEX that was not statistically significant.
  • After multivariable analysis using propensity score, no statistically significant differences in mortality or occurrence of septic abdominal complications was noted between those patients undergoing primary repair only or PEX.

DuBose et al (2008) conclude that the use of PEX in patients with severe duodenal injuries may contribute to longer hospital stay and confers no survival or outcome benefit.

The Western Trauma Association guidelines for management of duodenal injuries (Malhotra et al, 2015) include the algorithm below for determining management:

duodenal screenshot

Additional reading: Ginzburg E, et al. Pyloric exclusion in the management of duodenal trauma: is concomitant gastrojejunostomy necessary? The American Surgeon. 1997 Nov;63(11):964-966.

ONCOTYPE IQ for DCIS: A 12-year update on the ECOG-ACRIN E5194 study

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One discussion last week included Dr. Wood’s ONCOTYPE IQ for DICS, Trial E5194.

Reference: Solin LJ, et al. Surgical excision without radiation for ductal carcinoma in situ of the breast: 12-year results from the ECOG-ACRIN E5194 study. Journal of Clinical Oncology. 2015 Nov 20;33(33):3938-3944. doi: 10.1200/JCO.2015.60.8588

ClinicalTrials.gov NCT00002934.

Summary: The Eastern Cooperative Oncology Group–American College of Radiology Imaging Network (ECOG-ACRIN; formerly the Eastern Cooperative Oncology Group) Cancer Research Group E5194 study (a nonrandomized clinical trial) prospectively enrolled patients for whom surgical excision alone (without radiation) was thought to be a reasonable treatment option on the basis of low-risk clinical and pathologic characteristics. This report provides updated results from the ECOG-ACRIN E5194 study, including 10- and 12-year outcomes.

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The ACOSOG Z0011 Randomized Control Trial

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One discussion last week included the ACOSOG Z0011 RCT.

Reference: Giuliano AE, et al. Effect of axillary dissection vs no axillary dissection on 10-year overall survival among women with invasive breast cancer and sentinel node metastasis: the ACOSOG Z0011 (Alliance) randomized control trial. JAMA. 2017 Sep 12;318(10):918-926. doi: 10.1001/jama.2017.11470.

Summary: The results of the American College of Surgeons Oncology Group Z0011 (ACOSOG Z0011) trial were first reported in 2005 with a median follow-up of 6.3 years. Longer follow-up was necessary because the majority of the patients had estrogen receptor-positive tumors that may recur later in the disease course. In this follow-up study, the authors sought to determine whether the 10-year overall survival of patients with 2 or fewer sentinel lymph node metastases treated with breast-conserving therapy and sentinel lymph node dissection (SLND) alone without axillary lymph node dissection (ALND) is noninferior to that of women treated with axillary dissection.

Compared with ALND, SLND alone was found to be noninferior for overall survival. The 10-year overall survival rate was 86.3% in the SLND alone group and 83.6% in the ALND group. The unadjusted HR comparing overall survival between the SLND alone group and the ALND group was 0.85 (1-sided 95% CI, 0–1.16), which did not cross the prespecified noninferiority HR margin of 1.3. The HR for overall survival adjusting for adjuvant therapy (chemotherapy, endocrine therapy, radiation, or a combination of these 3) and age for the SLND alone group compared with the ALND group was 0.93 (1-sided 95% CI, 0–1.28) (Table 2).

10yr survival

CONCLUSION: In this randomized clinical trial including 856 women, after median follow-up of 9.3 years, overall survival for patients treated with sentinel lymph node dissection alone was not inferior to those treated with completion axillary lymph node dissection (86.3% vs 83.6%, respectively; noninferiority hazard ratio margin of 1.3). These findings do not support the use of axillary lymph node dissection when 2 or fewer metastases are found with sentinel lymph node sampling in women with cT1-2M0 breast cancer.