Discontinuing drugs before surgery

Canadian Journal of Anesthesia/Journal canadien d'anesthésie - In the majority of cases, patients should continue their usual medications preoperatively. Exceptions to this have been...     

The role of antiplatelet drugs in carotid reconstructive surgery.

Neurologic events following carotid reconstructive surgery for symptomatic cerebral occlusive disease are generally reported to be one to two per cent. One of the events leading to this incidence is thrombosis of the endarterectomized internal carotid artery (ICA) after surgery. Since antiplatelet drugs have been found to be effective in altering platelet-induced thrombosis, we undertook a clinical trial of administration of aspirin (or aspirin-like) drugs to a group of patients who were to undergo ICA endarterectomy. This group was then compared to a comparable group from the previous year in whom drugs had not been administered. Thrombosis resulting in hemiparesis occurred on six occasions in five patients in the group that did not receive drugs. Thrombosis was not observed in two patients exhibiting hemiparesis in the drugs group. On the basis of these results, we concluded that the incidence of neurological complications following carotid reconstructive surgery can be further reduced by the use of aspirin and aspirin-like drugs.     

深思与警觉：叫停变性术事件

“变性”已日渐成为夺人眼球的热门关键词，但我们看到的、听到的更多的是媒体的猎奇与整形机构的热炒。此种种现象非常令人担忧。[编者按]     

Anesthetic implications of the new anticoagulant and antiplatelet drugs

In this review, we discuss the anesthetic implications of the new anticoagulant and antiplatelet drugs, focusing our discussion mainly on neuroaxial/regional anesthesia and central catheter placement issues. We offer practical recommendations for their use.     

Effect of preoperative antiplatelet drugs on vascular prostacyclin synthesis

Patients undergoing aortocoronary bypass using autogenous saphenous veins were randomly divided into three comparable groups. Group 1 (n = 10) acted as a control, Group 2 (n = 14) received 80 mg of aspirin at midnight before the operation, and Group 3 (n = 12) received 80 mg of aspirin and 75 mg of dipyridamole at midnight and an additional 75-mg dose of dipyridamole at 6 AM. The purpose was to determine which regimen would maximally inhibit platelet function without depressing vascular prostacyclin synthesis. Serum thromboxane A2, saphenous vein wall and aortic wall prostacyclin, platelet aggregation, and bleeding time were measured in all patients. None was restarted on a regimen of aspirin or dipyridamole postoperatively. Aspirin alone and in combination with dipyridamole significantly inhibited thromboxane A2 and platelet aggregation in all treated patients but spared venous prostacyclin synthesis. Aortic prostacyclin synthesis was partially inhibited in both treated groups. Chest tube drainage was comparable in all three groups. These results indicate that the combination of aspirin and dipyridamole offers no measurable advantage over aspirin alone in the perioperative period.     

Non-steroidal anti-inflammatory drugs, antiplatelet medications and spinal axis anesthesia

Many individuals use cyclo-oxygenase inhibitors (COX-1 and COX-2 non-steroidal anti-inflammatory drugs) and antiplatelet medications on a regular basis. This is particularly true of the elderly, who are more prone to having osteoarthritis, rheumatoid arthritis, and cardiac disease. Some of these agents alter platelet function and may increase the risk of spinal/epidural hematoma formation if spinal axis anesthesia is utilized without following proper precautions. All anesthesiologists should be familiar with these agents and how they work. More importantly, they should be familiar with the established guidelines set forth by the American Society of Regional Anesthesia (ASRA) [Regional anesthesia in the anticoagulated patient-defining the risk (2002); Reg. Anes. Pain Med. 28 (2003)172], the German Society of Anesthesiology and Intensive Care Medicine (DGAI) [Anaesthesiol. Intensivmed. 38 (1997) 623], and the Spanish Consensus Forum [Rev. Esp. Anesthesiol. Reanim. 48 (2001) 270]. This article explains the mechanism of action of each of the medications which alter platelet function, defines the risks of hematoma formation should the medication be inadvertently continued into the perioperative period, and provides guidelines and recommendations on how to manage each class of drug prior to the placement of spinal/epidural blocks.     

Cardiac surgery in patients on antiplatelet and antithrombotic agents

The widespread application of antithrombotic agents carries significant potential for inducing excessive peri-operative hemorrhage during cardiac surgery. Specific surgical and medical strategies can be employed to attenuate this bleeding. These antithrombotic agents and anti-hemorrhagic measures will be reviewed in depth.     

Patient noncompliance before surgery

Study Type – Therapy (case series)
Level of Evidence 4

OBJECTIVE

To assess patient compliance with preoperative instructions and to determine causes and factors of noncompliance, as noncompliance might affect surgical outcome and has potential medicolegal implications.

PATIENTS AND METHODS

One surgeon counselled 101 consecutive patients before undergoing laparoscopic renal surgery. Deliberate discussions instructed patients to bring their radiograph films on the day of surgery and complete a preoperative bowel preparation. Noncompliance was defined as failure to bring films and/or complete bowel preparation. Patient demographics, socio‐economic and clinical variables were analysed, and reasons for failure to comply with instructions were also recorded.

RESULTS

Twenty‐four of the 101 (24%) patients were not compliant, 13 with films only, seven with bowel preparation only, and four with both sets of instructions. Univariate analysis showed that language and race were factors for noncompliance. Multivariate analysis showed that non‐Caucasians had 17 times the risk of noncompliance (P < 0.001); long distance from home to the site of care had five times the risk of noncompliance (P = 0.041), and each day between the initial consultation and the date of surgery had 1.05 times the risk of noncompliance (P < 0.001). The most common reason given by patients for noncompliance was that they were never given the preoperative instructions.

CONCLUSIONS

Noncompliance with preoperative surgical instructions is a significant issue and is increased in non‐Caucasian patients, those travelling long distances, and those whose surgery date is long after their preoperative consultation. A systems‐based approach is needed to address this significant issue.     

Locoregional anesthesia and blood coagulation: impact of new antiplatelet drugs

New antiplatelet drugs such as glycoprotein IIb/IIIa receptor antagonists, thienopyridines (adenosine diphosphate receptor antagonists), inhibitors of cyclooxygenase and phosphodiesterase, and antiaggregatory prostaglandins have been introduced in vascular medicine. This paper reviews the pharmacokinetics, mechanisms of action, indications, and side effects of platelet-inhibiting agents as well as methods for coagulation monitoring. Updated guidelines for the management of locoregional anesthesia in patients receiving new antiplatelet drugs are discussed. In this clinical situation, the decision for or against locoregional anesthesia must be preceded by a risk-benefit analysis based on history of bleeding, physical examination, and coagulation monitoring. Blockade should be performed as atraumatically as possible and specific time intervals must be maintained between the last administration of antiplatelet agents and the performance of the blockade or withdrawal of a catheter in all elective patients.