Complication rates following elective lumbar fusion in patients with diabetes: insulin dependence makes the difference.

STUDY DESIGN

Retrospective cohort.

OBJECTIVE

To determine the effect of non-insulin-dependent diabetes mellitus (NIDDM) and insulin-dependent diabetes mellitus (IDDM) on postoperative complications after elective lumbar fusion surgery.

SUMMARY OF BACKGROUND DATA

Diabetes mellitus (DM) is a common chronic disease. The effects of NIDDM and IDDM on rates of postoperative complications, extended length of stay, and readmission after lumbar fusion surgery are not well established.

METHODS

A retrospective cohort study was conducted using the American College of Surgeons National Surgical Quality Improvement Program database. Patients undergoing lumbar fusion between 2005 and 2012 were identified and characterized as having NIDDM, IDDM, or neither. Bivariate and multivariate analyses were used to test patients with NIDDM and IDDM for increased risk of adverse postoperative outcomes over the initial 30 postoperative days.

RESULTS

A total of 15,480 patients who underwent lumbar fusion were identified (13,043 were patients without DM, 1,650 patients had NIDDM, and 787 patients had IDDM).NIDDM was independently associated with an increased risk of wound dehiscence (relative risk = 2.3; P = 0.033) and extended length of stay (1.2; P < 0.003).IDDM was independently associated with an increased risk of death (2.7; P = 0.020), sepsis (2.2; P = 0.002), septic shock (3.3; P = 0.032), unplanned intubation (2.8; P = 0.003), ventilator-assisted respiration for more than 48 hours postoperatively (2.8; P = 0.005), wound-related infection (1.9; P = 0.001), urinary tract infection (1.6; P = 0.011), pneumonia (3.1; P < 0.001), extended length of stay (1.5; P < 0.001), and readmission within 30 days (1.5; P = 0.036).

CONCLUSION

Compared with patients without DM, IDDM was associated with an increased risk of a considerably higher number of postoperative complications than NIDDM. These complications were also of greater severity. This important designation may improve preoperative risk stratification and counseling of patients with diabetes prior to lumbar fusion surgery.

LEVEL OF EVIDENCE