The syndrome of inappropriate antidiuretic hormone secretion and its effect on blood indices following spinal fusion

Acute kidney injury following spinal instrumentation surgery in children

AIM

To determine acute kidney in jury (AKI) incidence and potential risk factors of AKI in children undergoing spinal instrumentation surgery.

METHODS

AKI incidence in children undergoing spinal instrumentation surgery at British Columbia Children’s Hospital between January 2006 and December 2008 was determined by the Acute Kidney Injury Networ classification using serum creatinine and urine output criteria. During this specific time period, all patients following spinal surgery were monitored in the pediatric intensive care unit and had an indwelling Foley catheter permitting hourly urine output recording. Cases of AKI were identified from our database. From the remaining cohort, we selected group-matched controls that did not satisfy criteria for AKI. The controls were matched for sex, age and underlying diagnosis (idiopathic vs non-idiopathic scoliosis).

RESULTS

Thirty five of 208 patients met criteria for AKI with an incidence of 17% (95%CI: 12%-23%). Of all children who developed AKI, 17 (49%) developed mild AKI (AKI Stage 1), 17 (49%) developed moderate AKI (Stage 2) and 1 patient (3%) met criteria for severe AKI (Stage 3). An inverse relationship was observed with AKI incidence and the amount of fluids received intra-operatively. An inverse relationship was observed with AKI incidence and the amount of fluids received intra-operatively classified by fluid tertiles: 70% incidence in those that received the least amount of fluids vs 29% that received the most fluids (> 7.9, P = 0.02). Patients who developed AKI were more frequently exposed to nephrotoxins (non steroidal anti inflammatory drugs or aminoglycosides) than control patients during their peri-operative course (60% vs 22%, P < 0.001).

CONCLUSION

We observed a high incidence of AKI following spinal instrumentation surgery in children that is potentially related to the frequent use of nephrotoxins and the amount of fluid administered peri-operatively.

Comparison of perioperative complications following staged versus one-day anterior and posterior cervical decompression and fusion crossing the cervico-thoracic junction

INTRODUCTION

Multilevel cervical pathology may be treated via combined anterior cervical decompression and fusion (ACDF) followed by posterior spinal instrumented fusion (PSIF) crossing the cervico-thoracic junction. The purpose of the study was to compare perioperative complication rates following staged versus same day ACDF combined with PSIF crossing the cervico-thoracic junction.

MATERIAL AND METHODS

A retrospective review of consecutive patients undergoing ACDF followed by PSIF crossing the cervico-thoracic junction at a single institution was performed. Patients underwent either same day (group A) or staged with one week interval surgeries (group B). The minimum follow-up was 12 months.

RESULTS

Thirty-five patients (14 females and 21 males) were analyzed. The average age was 60 years (37-82 years). There were 12 patients in group A and 23 in group B. Twenty-eight complications noted in 14 patients (40%) included: dysphagia in 13 (37%), dysphonia in 6 (17%), post-operative reintubation in 4 (11%), vocal cords paralysis, delirium, superficial incisional infection and cerebrospinal fluid leakage each in one case. Significant differences comparing group A vs. B were found in: the number of levels fused posteriorly (5 vs. 7; p=0.002), total amount of intravenous fluids (3233ml vs. 4683ml; p=0.03), length of hospital stay (10 vs. 18 days; p=0.03) and transfusion of blood products (0 vs. 9 patients). Smoking and cervical myelopathy were the most important risk factors for perioperative complications regardless of the group.

CONCLUSIONS

Staging anterior cervical decompression and fusion with posterior cervical instrumented fusion 1 week apart does not decrease the incidence of perioperative complications.

Hidden blood loss during posterior spine fusion surgery

BACKGROUND CONTEXT

Posterior spine fusion is associated with significant intra- and postoperative blood losses. When referring to the total blood loss during spine surgery, the standard is to measure the intraoperative bleeding plus the postoperative drainage. This ignores the "hidden" blood loss that was found to be significant in other fields of surgery.

PURPOSE

The purpose of this study was to examine whether posterior spine fusion carries a substantial hidden blood loss.

STUDY DESIGN/SETTING

A prospective study.

PATIENT SAMPLE

We prospectively studied 114 patients undergoing instrumented posterior spinal fusion at one center between January 2011 and April 2011.

OUTCOME MEASURES

Total blood loss, visible blood loss, and hidden blood loss.

METHODS

For each patient, the hidden blood loss was calculated by deducting the observed perioperative blood loss from the calculated total blood loss based on the hematocrit changes. We compared the percentage of the hidden blood loss out of the total blood loss for primary versus revision posterior spine fusion.

RESULTS

Primary decompression and posterior fusion patients had a mean total true loss of 1,439 mL. Their calculated hidden loss was 600 mL, 42% of the total loss. After revision posterior spinal fusion surgery, the mean total blood loss was 1,606 mL. The mean visible loss was 975 mL, and the mean hidden loss was 631 mL, 39% of the total loss. Thus, there was no statistical difference in the hidden blood loss between primary and revision posterior spinal fusion surgeries (p>.05). We did not find a significant difference in the percentage of the hidden blood loss between patients who underwent one, two, or three or more levels of surgery.

CONCLUSIONS

After posterior spinal fusion, there may be a large amount of the hidden blood loss.