The association of hypotension during non-cardiac surgery, before and after skin incision, with postoperative acute kidney injury: a retrospective cohort analysis.

Intra-operative hypotension is associated with acute postoperative kidney injury. It is unclear how much hypotension occurs before skin incision compared with after, or whether hypotension in these two periods is similarly associated with postoperative kidney injury. We analysed the association of mean arterial pressure < 65 mmHg with postoperative kidney injury in 42,825 patients who were anaesthetised for elective non-cardiac surgery. Intra-operative hypotension occurred in 30,423 (71%) patients: 22,569 (53%) patients before skin incision; and 24,102 (56%) patients after incision. Anaesthetised patients who were hypotensive had mean arterial pressures < 65 mmHg for a median (IQR [range]) of 5.5 (0.0-14.7 [0.0-60.0]) min.h-1 before skin incision, compared with 1.7 [0.3-5.1 [0.0-57.5]) min.h-1 after incision: a median (IQR [range]) of 36% (0%-84% [0%-100%]) of hypotensive readings were before incision. We diagnosed postoperative kidney injury in 2328 (5%) patients. The odds ratio (95%CI) for acute kidney injury was 1.05 (1.02-1.07) for each doubling of the duration of hypotension, p < 0.001. Postoperative kidney injury was associated with the product of hypotension duration and severity, that is, area under the curve, before skin incision and after, odds ratio (95%CI): 1.02 (1.01-1.04), p = 0.004; and 1.02 (1.00-1.04), p = 0.016, respectively. A substantial fraction of all hypotension happened before surgical incision and was thus completely due to anaesthetic management. We recommend that anaesthetists should avoid mean arterial pressure < 65 mmHg during surgery, especially after induction, assuming that its association with postoperative kidney injury is, at least in part, causal.

Treatment of acute fractures of the femoral shaft with reamed intramedullary interlocking AO nails.

OBJECTIVE: To review and audit our experience with closed intramedullary interlocking nailing for acute femoral shaft fractures. METHODS: All patients admitted to The Aga Khan University Hospital, over the last six years and with a minimum follow-up of twelve months, with acute fractures of the femoral shaft were included in the study. All patients treated for established non-unions and infections or with pathological fractures were excluded from the study. RESULTS: There were 89 fractures, 74% of whom were closed and 50% were associated with other orthopedic injuries. Most of these were younger patients involved in high velocity road traffic accidents. The union rate was 88% with 4.4% of fractures going into non-union. The remaining 8% of the fractures went into a phase of delayed union, but ultimately united, making the overall success rate to be 95.6%. The mean time for union was 11.5 weeks. At the final clinical follow-up, 4% of the patients had minor pain, 7% had limp, 4% had leg length discrepancy of more than 2 cm and 4% had decreased range of motion at the hip or knee joints. We had a 4% rate of superficial infection. There were 3 cases of pudendal nerve neuropraxia and 2 cases of deep vein thrombosis. CONCLUSION: Intramedullary Interlocking nailing is a safe and effective treatment modality for acute fractures of the femoral shaft. Proper surgical decision making regarding static versus dynamic mode of locking can avoid problems of delayed union.