Emory authors: Perioperative hyperglycemia management

One discussion this week included management of perioperative hyperglycemia.

Reference: Duggan EW, Carlson K, Umpierrez GE. Perioperative hyperglycemia management: an update. Anesthesiology. 2017 Mar;126(3):547-560. doi: 10.1097/ALN.0000000000001515.

Summary:  A substantial body of literature demonstrates a clear association between perioperative hyperglycemia and adverse clinical outcomes. The risk for post-operative complications and increased mortality relates to both long-term glycemic control and to the severity of hyperglycemia on admission and during the hospital stay. This study reports on the prevalence, diagnosis and pathophysiology of perioperative hyperglycemia and provides a practical outline for the management of surgical patients with diabetes and hyperglycemia.

The sections addressed include:

  • Metabolic consequences of surgical stress and anesthesia
  • Prevalence of hyperglycemia and diabetes in surgical patients
  • Preoperative period
  • Diabetes, fasting and feeding
  • Intraoperative period
  • Postoperative period
  • Glycemic targets
  • Pre-operative glycemic management
  • Intraoperative glycemic management
  • Post-operative glycemic management for non-ICU patients
  • Transitioning from IV to SC insulin
  • Insulin pump therapy
  • Hypoglycemia
  • Glucose monitoring in the perioperative period

CONCLUSION: Hyperglycemia is common in surgical patients. Current data demonstrates an association between elevated BG and a risk of perioperative complications in diabetic and non-diabetic patients. Insulin administration intra- and post-operatively has been shown to improve clinical outcomes. Individual patient characteristics and surgical case factors are considered when choosing subcutaneous insulin or an insulin infusion. Both are appropriate options on the day of surgery. Blood glucose values of 180 mg/dL (10 mmol/L) or higher are treated with insulin. Target range for the perioperative period is 140-180 mg/dL (7.7-10 mmol/L). Post-operatively, surgical floor patients with poor or uncertain oral intake are treated with once daily basal insulin. Prandial insulin is added when patients tolerate oral intake. Increasing evidence suggests a role for incretin therapy during the peri-operative period in patients with type 2 diabetes.

Multiple teams care for a surgical patient during the hospital course (anesthesiology, surgery, critical care medicine, internal/hospital medicine and endocrinology). Therefore, multidisciplinary groups within an institution should work together to create appropriate protocols for hyperglycemia screening, monitoring and treatment to minimize errors and to better care for patients.

Are diabetic patients at greater risk for anastomotic leaks and mortality when undergoing colectomies?

One discussion this week included postoperative anastomotic leaks.

Reference: Ziegler MA, et al. Risk factors for anastomotic leak and mortality in diabetic patients undergoing colectomy: analysis from a statewide surgical quality collaborative. Archives of Surgery. 2012 Jul;147(7):600-605. doi: 10.1001/archsurg.2012.77.

Summary: In a database review of patients in Michigan who underwent colectomy, the study aimed to determine risk factors in diabetic patients that are associated with increased postcolectomy mortality and anastomotic leak.

Primary risk factors were diabetes mellitus, hyperglycemia, steroid use, and emergency surgery. Of the 5123 patients, 889 were diabetic, 4234 were nondiabetic.

Diabetes alone was not found to be a risk factor for anastomotic leak in this study.

  • 56% of diabetic patients had preoperative glucose levels of 140 mg/dL or higher
  • Preoperative steroid use led to increased rates of anastomotic leak in diabetic patients
  • Diabetic patients who had a leak had more than a 4-fold higher mortality (26.3% vs 4.5%, P<.001) compared with nondiabetic patients (6.0% vs 2.5%, P<.05).
  • Mortality was associated with hyperglycemia for nondiabetic patients only

The authors conclude that improved screening may identify high-risk patients who would benefit from perioperative intervention.

Clinical guideline for management of sigmoid volvulus

One discussion this week included revolvulus after colonic decompression.


Reference: Vogel JD, et al. Clinical practice guidelines for colon volvulus and acute colonic pseudo-obstruction. Diseases of the Colon and Rectum. 2016 Jul;59(7):589-600. doi: 10.1097/DCR.0000000000000602

Summary: Volvulus occurs in the sigmoid colon or cecum in >95% of cases, with the remainder involving either the transverse colon or the splenic flexure of the colon. Sigmoid volvulus affects patients who are older, with more comorbid medical and neuropsychological conditions, compared with those with cecal volvulus.

Continue reading

Foreign body removal without hospitalization: a new use for a stent removal device

One discussion this week involved the removal of foreign bodies.

Reference: Smith PM, et al. Isiris: a novel method of removing foreign bodies from the lower urinary tract to avoid unnecessary hospitalization and anesthesia. Journal of Endourology Case Reports. 2016 Aug 1;2(1):144-147. doi: 10.1089/cren.2016.0086.

Summary: Polyembolokoilamania refers to the practice of inserting foreign bodies (FBs) into natural orifices. A FB within the urethra is a relatively rare phenomenon with 646 cases recorded last year in the United Kingdom. Management of these patients presents technical challenges and complexities because of underlying psychiatric disorders that are often associated. This case illustrates a novel way of removing FBs from the genitourinary tract, requiring less resources, preventing hospital admission, and attempts to break the cycle of behavior, leading to recurrent attendance with polyembolokoilamania.

A 38-year-old Caucasian male prisoner, with psychiatric history presented to the emergency department (ED) with a history of inserting FBs into his urethra on 12 different occasions over a 6-week period. Of these 12 attendances, 3 resulted in admission and 2 required emergency intervention in theater under general anesthesia. After the third attendance in 5 days, it was decided to use Isiris™, a single-use flexible cystoscopy device with a built-in ureteral stent grasper, to remove the FBs and check the integrity of the urethra. The procedure was performed within the ED, without the need for admission to a ward bed or general anesthesia. Furthermore, only two members of staff were required to remove all of the urethral FBs.

Isiris, although marketed as a stent removal device, enabled us to remove all the patient’s FBs in one procedure. Isiris is an easy to use device, similar to a flexible cystoscope, that a specialist nurse or resident would be familiar using. It allows efficient and safe removal of lower urinary tract FBs, even out of hours. It requires minimal staffing support and can be done in the ED. It has the potential to reduce associated sequela of urethral polyembolokoilamania, saving resources while preserving the availability of the emergency theater.

Outcomes of and predictors for bowel ischemia after AAA repair: a study of 7312 patients

One discussion this week included AAA repair. The article cited here was provided by the chief resident.

Reference: Ultee KH, et al. Incidence of and risk factors for bowel ischemia after abdominal aortic aneurysm repair. Journal of Vascular Surgery. 2016 Nov;64(5):1384-1391. doi: 10.1016/j.jvs.2016.05.045.

Summary: Bowel ischemia is a rare but devastating complication after abdominal aortic aneurysm (AAA) repair. Its rarity has prohibited extensive risk-factor analysis, particularly since the widespread adoption of endovascular AAA repair (EVAR); therefore, this study assessed the incidence of postoperative bowel ischemia after AAA repair in the endovascular era and identified risk factors for its occurrence

METHODS: A total of 7312 patients undergoing intact or ruptured AAA repair in the Vascular Study Group of New England (VSGNE) January 2003 – November 2014 were included. Patients with and without postoperative bowel ischemia were compared and stratified by indication (intact and ruptured) and treatment approach (open repair and EVAR). Criteria for diagnosis were endoscopic or clinical evidence of ischemia, including bloody stools, in patients who died before diagnostic procedures were performed. Independent predictors of postoperative bowel ischemia were established using multivariable logistic regression analysis.

RESULTS: Postoperative outcomes (p.1389):

AAA repair

RESULTS: Predictors of bowel ischemia after AAA repair (p.1390):

AAA predictors

CONCLUSIONS: The authors state that “these date should be considered during operative planning in an effort to adequately assess patient risk for bowel ischemia and undertake efforts to reduce it” (p.1391).

Can vein diameter predict arteriovenous fistula maturation?

One discussion this week included the relationship between vein size and fistula failure.

Reference: Bashar K, et al. The role of venous diameter in predicting arteriovenous fistula maturation: when not to expect an AVF to mature according to pre-operative vein diameter measurements? A best evidence topic. International Journal of Surgery. 2015 Mar;15:95-99. doi: 10.1016/j.ijsu.2015.01.035.

Summary: This best evidence topic was investigated according to a described protocol, and asked the question: what is the minimal vein diameter that can successfully predict maturation of an arteriovenous fistula (AVF) in patients undergoing dialysis?

The search retrieved 804 papers, of which 5 represented the best evidence to answer the clinical question. All studies assessed the association between successful AVF maturation and the size of vein used.

Highlighted findings:

  1. The strongest evidence came from a non-randomised controlled follow-up study in which 76% of fistulas created using >2 mm cephalic vein successfully matured compared to 16% when the vein measured ≤2 mm.
  2. Another prospective, multicentre study showed 65% successful maturation using veins >4 mm compared to 45% with veins < 3 mm. Vein diameter was found to be an independent predictor of maturation in multivariate regression analysis in two retrospective observational studies.
  3. A retrospective observational study found that using venous measurements of ≥2.5 mm following tourniquet application resulted in more fistulas been created that would have otherwise been denied based on venous ultrasound mapping.
  4. Routine use of tourniquet makes it possible to form AVFs in patients who otherwise would have been rejected. One study showed good results from using a transposed BBAVF when a BCAVF was deemed inappropriate following US.

In conclusion, a vein diameter of <2.5 mm should be considered inadequate for formation of an AVF, particularly if those measurements remain unchanged following the use of tourniquet.

The timing and accuracy of SLNB for nodal management after NAC

One discussion this week included nodal management after neoadjuvant chemotherapy (NAC).


Reference: Pilewskie M and Morrow M. Axillary nodal management following neoadjuvant chemotherapy. JAMA Oncology. 2017 Apr 1;3(4):549-555.

Summary: The increasing use of NAC has raised questions about the optimal approach to the axilla, including accuracy and timing of sentinel lymph node biopsy (SLNB) in patients who are clinically node negative (cN0) at presentation, use of NAC to avoid axillary lymph node dissection (ALND) in patients presenting with node-positive disease, and the relative importance of pre-and post-NAC stage in predicting the risk of locoregional recurrence (LRR).

The decrease in nodal metastases in cN0 patients undergoing post-NAC axillary staging and the increasing rates of pCR in the breast in patients treated with current chemotherapy regimens led to the study of SLNB among patients presenting with cN+ disease. Table 3 (below) summarizes data from three prospective, multi-institutional trials assessing the accuracy of SLNB after NAC among node-positive patients.

SLNB

The authors conclude: NAC reduces the need for ALND, and SLNB is an accurate
method of determining nodal status post NAC. The demonstration that SLNB accurately stages the axilla after NAC regardless of the presenting nodal stage (cN0, cN1) provides an important rationale for the use of NAC for axillary downstaging in patients who are candidates for breast-conserving surgery at presentation or who desire mastectomy. SLN identification rates and FNRs in those who are cN0 are similar to those seen with initial SLN surgery, and nodal recurrence after a negative SLNB is uncommon.

 

Additional Reading: Boughey JC, et al. Sentinel lymph node surgery after neoadjuvant chemotherapy in patients with node-positive breast cancer: the ACOSOG Z1071 (Alliance) clinical trial. JAMA. 2013 Oct 9;310(14):1455-1461. doi:10.1001/jama.2013.278932.