www.postersession.com

Post-operative nausea and vomiting (PONV) is a common issue that impacts patient comfort and satisfaction and can delay discharge.

Studies have reported an average incidence of PONV of up to 38.3% following common surgeries (1). The most common predictors for PONV include: female gender, prior history of PONV, non-smoking

status, and the use of postoperative opioids. If none or only one risk factor is present the incidence of PONV varies between 10%-20% (2).

 Increases in intracranial pressure with Valsalva from PONV in

craniotomy patients can result in tissue swelling, hemorrhage, or hematoma formation at the site of surgery, compromising the

perioperative outcome (3). In a prospective 2011 study, incidence of PONV in the first 24 hours after craniotomy was 47% while other

analyses reported PONV rates ranging from 10% to 74%. The comparatively higher incidence of PONV following craniotomy

suggest that intracranial procedures should be considered a risk factor (4). Intracranial surgery likely poses an independent risk due to procedure-induced changes in the intracranial pressure and duration

of procedure/anesthesia (4).  

During a 1986 visit to China, J W Dundee was impressed by the use of acupressure at the point Pericardium 6 (P6; also known as

Neiguan) as prophylaxis against vomiting during early pregnancy. P6 is 2 Chinese inches (cun units) proximal to the wrist crease between

the tendons of palmaris longus and the flexor carpi radialis muscles of the forearm. A cun is equivalent to the distance between the proximal

and sital interphalangeal joints of the flexed index finger or roughly the width of the thumb across the inter-phalangeal joint (5).

  Dundee conducted the first study of the anti-emetic effects of

acupuncture at P6 on patients under general anesthesia(5). In the following years, further data demonstrated the effectiveness of

acupoint electrical stimulation at P6 in both preventing and treating nausea and vomiting in multiple settings (3,6,7). Systematic review

has shown P6 stimulation to prevent nausea and vomiting (7). While well established as a method for the prevention of PONV, the ability

of P6 electrostimulation to provide additional protection against PONV in patients who have previously failed pharmacologic therapy is

unknown. 

Various methods of stimulating P6 include needle-penetrating acupuncture, electro acupuncture, transcutaneous electrical

stimulation, or acupressure. While these methods may not differ in effectiveness, they do vary in ease and cost of implementation.

Recently, a series of studies has utilized neuromuscular blockade monitors (NMBMs) to stimulate P6 intra-operatively (8,9,10).

Electrodes attached to a conventional nerve stimulator receive a frequency of 1Hz over the ulnar nerve, simultaneously providing

constant P6 stimulation and testing the neuromuscular block for the duration of the anesthetic (8,11).

The degree of muscle activity prompted by a NMBM, indicates the depth of a neuromuscular blockade, allowing the anesthesiologist to adjust dosing and thus decrease the incidence of side effects (ex.

injuries caused by movement during pinning in craniotomies). Additionally, because no needles are used, patients are at no risk of infection or tissue damage from needles (8). This method employs a standard anesthesia tool and, beyond anesthesiologist training on P6

point location, requires no additional resources for implementation. However, existing trials compare NMBM to no prophylaxis rather than

as an adjunct to pharmacological prophylaxis.

Case Presentation Conclusions

Intraoperative Electrical Stimulation of Acupoint P6 for Prevention of Post-operative Nausea and Vomiting in

Patients Undergoing CraniotomyCaroline Walsh, Katharine Hagan, MD, Alicia M. Kowalski, MD

MD Anderson Cancer Center

Logo

Bibliography1. Apfel CC, Kranke P, Eberhart LH. Comparison of surgical site and patient’s history with a simplified risk score for the prediction of post operative nausea and vomiting. Anesthesia. 2004;59:1078-1082. Doi:10.1111/j.1365-2044.2004.03875.x.2. Apfel CC, Laara E, Koivuranta M, Greim CA, Roewer N. A simplified risk score for predicting postoperative nausea and vomiting: conclusions from cross-validations between two centers. Anesthesiology. 1999;91:693-700. Doi: 10.1097/00000542-199909000-00022. 3. Xu, M., et al., The effects of P6 electrical acustimulation on postoperative nausea and vomiting in patients after infratentorial craniotomy. J Neurosurg Anesthesiol, 2012. 24(4): p. 312-6.4. Latz B, Mordhorst C, Kerz T, Schmidt A, Schneider A, Wisser G, Werner c, Engelhard K. Postoperative nausea and vomiting in patients after craniotomy: incidence and risk factors. J Neurosurg. 2011;114:491-496. Doi: 10.3171/2010.9.JNS10151. 5. Dundee, J.W., et al., Traditional Chinese acupuncture: a potentially useful antiemetic? Br Med J (Clin Res Ed), 1986. 293(6547): p. 583-4.6. Lv JQ, Feng RZ, Li N. P6 acupoint stimulation for prevention of postoperative nausea and vomiting in patients undergoing craniotomy: study protocol for a randomized controlled trial. Trials 2013, 14: 153 doi: 10.1186/1745-6215-14-1537. Vickers, A.J., Can acupuncture have specific effects on health? A systematic review of acupuncture antiemesis trials. J R Soc Med, 1996. 89(6): p. 303-11.8. Arnberger, M., et al., Monitoring of neuromuscular blockade at the P6 acupuncture point reduces the incidence of postoperative nausea and vomiting. Anesthesiology, 2007. 107(6): p. 903-8.9. Khan, R.M., et al., Intraoperative stimulation of the P6 point controls postoperative nausea and vomiting following laparoscopic surgery. Can J Anaesth, 2004. 51(7): p. 740-1. 10. Liu, Y.Y., et al., Evaluation of transcutaneous electroacupoint stimulation with the train-of-four mode for preventing nausea and vomiting after laparoscopic cholecystectomy. Chin J Integr Med, 2008. 11. Scuderi, P.E., P6 stimulation: a new approach to an ancient technique. Anesthesiology, 2007. 107(6): p. 870-2.12. Watcha, M.F., The cost-effective management of postoperative nausea and vomiting. Anesthesiology, 2000. 92(4): p. 931-3. 13. Gan, T.J., et al., Consensus guidelines for the management of postoperative nausea and vomiting. Anesth Analg, 2014. 118(1): p. 85-113. 14. Lee, A. and L.T. Fan, Stimulation of the wrist acupuncture point P6 for preventing postoperative nausea and vomiting. Cochrane Database Syst Rev, 2009(2): p. CD003281.

Post-operative nausea and vomiting increases patient discomfort, causes unwarranted side effects, and often results in higher hospital bills (ex. readmission, extra anti-emetics). Current pharmacological

approaches for craniotomy patients focus primarily on selective serotonin receptor antagonists (5HT3) because of their favorable safety

profiles and lack of sedative side effects (eg. ondansetron) (4). However, the cost of these drugs can add to medical bills, with

ondansetron costing $7.08 per 4mg dosage and aprepitant costing $128.70 per 40mg dosage. Single-drug prophylaxis of PONV has a very high failure rate, with the consequential addition of hundreds of

millions of dollars annually to the cost of post-op care (12). The effects of different classes of anti-emetics are additive and thus the standard of care for patients at moderate or high risk of PONV is multi-agent prophylaxis (13). P6 stimulation should be considered as

an adjunct to pharmacological anti-emetics due to low cost and ease of use. A 2009 Cochrane case review included only one study where P6 stimulation was combined with pharmacological prophylaxis and the results of this trial were unclear (14). The advantage of the NMBM method of PONV prophylaxis is its ease of application, and its cost-

effectiveness since the materials and personnel for application (i.e. an anesthesiologist and NMBM and electrodes) represent routine costs for craniotomies. The results of this retrospective study suggest that while

reducing the incidence of PONV overall, unilateral stimulation of P6 using NMBM also reduces the amounts of antiemetic medications

required post-operatively. Futhermore, application of P6 electrostimulation was achieved without inconvenience or additional time for the anesthesia team, implying that this is a relatively simple

method of preventing PONV that may be utilized with little extraneous cost or training.

This retrospective study suggests that P6 electrostimulation with NMBM may decrease PONV

when used as an adjunct to pharmacological prophylaxis. Furthermore, its use requires minimal

training and additional time or expense. However, a randomized controlled trial is needed to verify that P6

electrostimulation decreases PONV beyond that which would be achieved with pharmacological prophylaxis in

the at risk population.

Introduction DiscussionPatient One:

Past Medical History:  44 year old male with history of meningioma presenting for craniotomy for repair of CSF leak. Patient has a history of PONV and motion sickness. Standard ASA monitors applied and induction and intubation occurred without incident. Stimulation: P6 stimulation on the left due to Parkinson’s induced weakness of right side at 1Hz (1 pulse/second), using two leads of a Neurotech nerve stimulator. Intensity of the electric stimulation (mAmps) was determined by starting at the highest intensity and then reducing stimulation until twitching was not visible. Electrostimulation continued throughout the procedure, and was discontinued just prior to extubation. Intraoperative concerns:Propofol infusion and volatile anesthetic used throughout procedure.Intraoperative narcotics: remifentanil continuous infusion, fentanyl 125 mcgIntraoperative anti-emetics: famotidine 20 mg, dexamethasone 10mg, ondansetron 8mg Postoperative: No PONV in PACU Post-operative anti-emetics: None P6 electrostimulation tolerated without problem Patient Two:

Past Medical History: 69 year old male with intracranial lymphoma presenting for left occipital craniotomy. Patient has a history of PONV. No preoperative anti-emetics given. Standard ASA monitors applied and induction and intubation occurred without incident. Stimulation: P6 stimulation at 1 Hz on the left due to lateral positioning, . Intensity of electric stimulation (mAmps) was determined by starting at the highest intensity and then reducing stimulation until twitching was not visible. Electrostimulation was maintained throughout the procedure, and was discontinued as soon as the pins were removed, prior to extubation. Intraoperative:Volatile anesthetic usedIntraoperative narcotics: fentanyl 250 mcgIntraoperative anti-emetics: dexamethasone 10 mg, ondansetron 4 mg Postoperative:No PONV in PACU Postop anti-emetics: NoneP6 electrostimulation tolerated without problem Patient Three:

Past Medical History: 39 year old female with right clinoidal meningioma presenting for craniotomy. Patient complains of numbness of the left half of her body and frequent headaches. Past medical history of Type 1 diabetes . History of PONV and motion sickness. No preoperative anti-emetics given. Standard ASA monitors applied and induction and intubation occurred without incident.  Stimulation: P6 stimulation on the left at 1Hz. Intensity of electric stimulation (mAmps) was determined by starting at the highest intensity and then reducing stimulation until twitching was not visible. This continued throughout the procedure, and was discontinued as soon as the pins were removed, just prior to extubation.  Intraoperative concerns:Volatile anesthetic usedIntraoperative narcotics: continuous infusion of remifentanilIntraoperative anti-emetics: dexamethasone 10 mg, ondansetron 4mg, aprepitant 40mg Postoperative:No PONV in PACUPostop anti-emetics: noneP6 electrostimulation tolerated without problem

Fig 1. Diagram of Pericardium 6 Locationhttps://debbieleetcm.files.wordpress.com/

2013/01/pc-6.png

Fig 2. Neurotechnology Digistim III Neuromuscular Blockade Monitor used to stimulate P6

http://www.ccrmed.com/Documents/Nerve%20Stimulators%20Neuro%20Techn...pdf