From the Literature

 

Published: Sep 2019

Delay in detection and treatment of perioperative anemia in hip fracture surgery and its impact on postoperative outcomes.
Clemmesen CG, Palm H, Foss NB
Injury 2019; Sep 3 [Epub ahead of print].
Pub Med
NATA rating :

 

REVIEW by:
S. Lasocki

 

NATA REVIEW:
Due to population ageing, hip fracture is becoming a major health concern. Indeed, short-term postoperative mortality is high (3-5%) and postoperative delirium is a common complication after hip fracture surgery, and their incidence is increased in case of preoperative anaemia. However, the detection of perioperative anaemia may be delayed.

This study evaluated the impact of noninvasive continuous Hb monitoring using the SpHb (Masimo Corp., USA) for the detection of severe perioperative anaemia (i.e. Hb <10 g/dL) in hip fracture patients. This was a 6-month prospective observational study conducted in a University hospital in Denmark. The authors analysed 42 patients (aged 78 ± 8 years, 42.5% male, 65% ASA I/II) among 51 enrolled ones (inclusion criteria: age ≥65 years and confirmed hip fracture).

The majority of patients were operated under epidural anaesthesia (started preoperatively for analgesia). All patients were monitored using a Radical-7 pulse oximeter and Rainbow sensors (Masimo Corp., USA) that give SpHb (i.e. non-invasive measurement of Hb) from 12 hours before surgery until 24 hours after. The monitor was blinded to all caregivers. A blood count was obtained daily for the first 3 postoperative days.

Twenty-two (52%) patients had at least one lab Hb value below 10 g/dL (the predefined transfusion trigger). This low Hb was detected in 15 (75%) patients by the SpHb (3 patients had not enough SpHb data and 4 had an SpHb >10 g/dL). The delay for detection of a low Hb was only 1.07 ± 2.84 hours earlier using SpHb. Interestingly, patients with postoperative delirium had a more prolonged cumulated time with low SpHb (162 [30-819] vs. 22 [0-70] minutes; P = 0.034).

Unfortunately, the investigators were not able to conduct the study as initially planned – with a monitoring period beginning at admission and lasting until the third postoperative day – because of too many missing data. The “improved” delay they reported does not appear to be clinically significant.

This study indicates that SpHb should probably not be used to replace invasive blood count surveillance, but it could provide some helpful additional information, for example to request a blood sample in case of decreasing SpHb. In addition, the investigators did not take into account the information given by the PVI (pulse variability index), which could help distinguish between haemodilution (low SpHb, low PVI) and bleeding (low SpHb, high PVI).


– Sigismond Lasocki