Effect of pre-emptive analgesia by continuous femoral nerve block on early postoperative cognitive function following total knee arthroplasty in elderly patients

Abstract

Abstract. To the best of our knowledge, the effect of pre-emptively blocking pain transmission on acute postoperative cognitive dysfunction (POCD) has not yet been assessed. Therefore, the present study aimed to investigate the effect of pre-emptive analgesia via a continuous femoral nerve block (CFNB) on postoperative pain and early cognitive function following total knee arthroplasty (TKA) surgery in elderly patients. CFNB was performed prior to TKA surgery in the preemptive analgesia group (n=30) and following TKA surgery in the control group (n=30). POCD was defined as a two-point reduction in the postoperative score compared with the preoperative score in the mini-mental state examination. The visual analog scale (VAS) was used to evaluate the intensity of pain at rest and during exercise. The intraoperative dose of remifentanil in the pre-emptive analgesia group was significantly lower than in the control group (P<0.01). In the preemptive analgesia group, VAS scores at three days post-surgery were lower than those in the control group (P<0.01). The incidence of POCD on the third postoperative day was slightly lower in the pre-emptive analgesia group compared with the control group. In conclusion, the results demonstrate that pre-emptive analgesia by CFNB may promote the recovery of early cognitive function following TKA in elderly patients. IntroductionPostoperative cognitive dysfunction (POCD) describes the memory and intellectual impairment that occurs in certain individuals during the perioperative period (1,2). A major risk factor for POCD is age; therefore, it is particularly prevalent in the elderly (2). Pain is also considered to be a risk factor for POCD as the areas of the brain involved in pain perception and cognitive control overlap (2,3). Total knee arthroplasty (TKA) has been reported to be one of the most painful orthopedic surgeries (4).Postoperative pain is intensified by sensitization of the pain receptors in the spinal cord and brain (5). This sensitization may be due to a perioperative inflammatory response, in which inflammatory mediators released at the operative site sensitize peripheral pain receptors (6). The ensuing increased nociceptive input to the spinal cord sensitizes the pain receptors there and this sensitization, in turn, sensitizes the pain receptors in the brain.If pain impulses from the operative site were interrupted throughout as well as following surgery, both intra-and postoperative peripheral pain stimuli could be blocked from transmitting to the central nervous system, thus reducing sensitization of pain receptors in the brain. If the occurrence of POCD is associated with the development of this sensitization, as has been suggested previously (6), initiating a blockade of pain transmission prior to, rather than following, surgery may decrease the incidence of POCD.Femoral nerve block (FNB) reduces pain transmission from the TKA operative area (7) and when FNB is administered during TKA, following spinal anesthesia postoperative pain is reduced (4). In tendon graf...

Perioperative Continuous Femoral Nerve Block Reduces Postoperative Cognitive Dysfunction of High-Risk Patients with Femoral Neck Fracture: Evidence from a Retrospective Propensity-Matched Study

“…MMSE is one of the most widely used scales in evaluating cognitive function, and a previous study defined POCD as a postoperative MMSE score >1 standard deviation below the preoperative score [24]. Deng et al used the MMSE score >1 standard (equal to 2 points) and reported that preemptive use of cFNB could enhance the recovery of cognitive function in patients undergoing TKA surgery [11]. We also adopted the latter criteria and achieved similar results.…”

“…As previously described [11], supine position was placed for patients of cFNB group the with the target leg a little abducted.…”

“…The Mini-Cog score is a brief and validated tool used in the evaluation of cognitive function of elderly patients undergoing elective surgery [9] which demonstrates good performance in predicting postoperative complications [10]; while the MMSE has been widely used as the diagnostic tool for POCD [2]. A study showed that preemptive application of continuous femoral nerve block (cFNB) could enhance analgesia and decrease the incidence of POCD, which assumes that relief of pain could reduce the sensitization of pain receptors [11]. However, there is rarely evidence investigating the influence of cFNB on the onset of POCD among patients undergoing femoral neck fracture surgery.…”

Protective Effect of Celecoxib on Early Postoperative Cognitive Dysfunction in Geriatric Patients

“…A recent study showed that satisfactory analgesia can decrease the incidence of POCD following total knee arthroplasty (TKA) in geriatric patients. ( 23 ) Animal studies demonstrated that postoperative pain might cause memory deficits ( 24 ), and such effects were reversed by a non-steroidal anti-inflammatory drug via its analgesic effects in animals ( 25 ). In the present study, celecoxib did not show an additional advantage of analgesia within 48 h post-surgery due to the efficiency of PCA.…”

Mechanism of gastrodin in cell apoptosis in rat hippocampus tissue induced by desflurane

“…Postoperative cognitive dysfunction often leads to mental disorders, personality changes, memory loss, anxiety and other mental symptoms, which is caused by central nervous system damage due to surgery or anesthesia, seriously affecting the life quality of patients ( 1 , 2 ). It has been reported that the commonly-used anesthetics, such as isoflurane and ketamine, can cause postoperative cognitive dysfunction.…”