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Catheter Technique in Peripheral Regional Anesthesia

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Introduction

The clinically established catheter procedures are those performed close to the spinal cord. By comparison, peripheral catheter techniques play a more subordinate role. A survey on catheter-based postoperative analgesia conducted by Lehmann found that lumbar and thoracic epidural and spinal catheters were used at a frequency of 85%, plexus catheters 11.5% of the time and other procedures like intercostal, interpleural catheters and femoral nerve catheters were only used in 3.5% of the cases. The advantages of the regional anaesthesia in our increasingly older and multimorbid patients should encourage us to turn to the use of regional methods of anaesthesia whenever possible. At the same time, safety and comfort aspects, such as fasting, PONV (postoperative nausea and vomiting), and freedom from postoperative pain are equally of significance. Especially for pain management after surgery on the lower extremity, continuous peripheral nerve blocks (PNB) show the same efficacy as the EDA, with a low risk profile and high degree of comfort for the patient. The prerequisites for a high acceptance of regional anaesthesia procedures among patients, surgeons and anaesthesiologists are optimally pain-free puncturing, quick location of nerves, a high rate of success, good operating theatre conditions (motoric block), long-acting postoperative analgesia, few side effects, rare and readily managed complications.
 

Indications for catheter use

  • Continuous regional analgesia
  • Acute pain therapy (postoperative)
  • Management of chronic pain (CRPS)
  • Supportive adjunct to physiotherapy/exercise therapy
  • Sympatholysis (for improving wound healing)
  • Preventive analgesia (phantom pain prophylaxis)

 

Possible catheter techniques

In principle, a pain catheter can be used together with all of the blocks described in this tutorial. For all procedures, the catheter is equipped with a connector and bacteria filter, fixated using bandage strips and covered with a sterile dressing. Before attaching the filter, an aspiration test must rule out any intravasal positioning of the catheter.

catheters

 

Equipment and Drugs

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catheter materialsCatheter sets, pumps and disposables

In our hospital, we use Contiplex D sets exclusively, placing great emphasis on soft catheters without a stylet. For inpatient postoperative pain management, we preferentially equip our catheters with PCA pumps. Alongside the electronic devices, we also employ so-called elastomeric pumps (mechanical). Their easy handling and error-free operation make these single-use pumps ideal for use in outpatient settings.

Local anaesthetics 
For postoperative analgesia, we routinely use 0.2% ropivacaine. The drug is best administered by PCA pump with a basal rate and bolus option. Continuous infusion is equally possible. For the most part, we have turned away from purely bolus injections. The decision as to which of these to use depends on the organisational structure. The decisive advantage of continuous administration is that it ties up less anaesthesia staff, and the nursing staff on the peripheral wards can adjust the doses independently within the prescribed range. Disturbing motor blocks on 0.2% ropivacaine are rare. In the postoperative sector, we do not routinely use any other local anaesthetics.

catheters2

 

Contraindications

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For the catheter technique, the contraindications are in line with those that apply to single-shot techniques. When a bacteriemia can be presumed, the indications for a catheter must be subject to very rigorous review.

  • Infections in the puncture area
  • Systemic (bacterial) infection
  • Refusal of the procedure by the patient

Complications

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  • Dislocation of the catheter
  • Infections at the puncture site
  • Catheter breakage, formation of knots or loops (rare)
  • Toxic reactions (rare)

Catheter dislodgment resulting from the patient‘s movements is rare. The analgesic effect following injection of the local anaesthetic is weakened or absent. In such cases, the catheter must be removed. In our opinion, it is not necessary to fixate the catheter with a suture. This type of fixation can create a shear point. To date we have not encountered any complications involving other types of dislodgment or any instances of catheter breakage. Although we frequently use catheters in immunocompromised patients (diabetics, patients receiving longterm cortisone and/or methotrexate therapy), there have been virtually no serious cases of local infection. It goes without saying that catheter placement is performed under sterile conditions (facemask, gloves). Toxic reactions have not been observed to date and are not to be anticipated either during continuous infusion at the aforementioned doses or at a bolus dose given repeatedly at intervals of approx. 6-8 hours.

Organisation

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The majority of pain catheters are placed in conjunction with a surgical intervention. After the operation, the patients will be initially monitored in the recovery room. A functional renewal of the block is not necessary until the patient has been transferred to the peripheral ward. In rather rare cases, elective catheters used for physiotherapy, sympatholysis in OAD patients or in patients with reflex sympathetic dystrophy. For every patient who receives a catheter, we establish an accompanying patient chart. The chart contains a record of the patient‘s data, the type of catheter, the depth of needle penetration required for successful stimulation and the date the catheter was placed. Every patient who leaves the recovery room with a pain catheter is entered into a catheter database we have set-up ourselves. A current list of all „pain catheter patients“ can be viewed at any time from any PC workstation. Two to three times a day on our „pain rounds“, we check the effect on a visual analogue scale, the patient‘s satisfaction, if continuation of therapy is indicated, the motor and sensory responses in the region of anaesthesia and if any side effects have occurred. We conduct a palpation check every day and inspect the puncture site every two days when we change the dressing in order to identify any inflammatory complications at an early stage. The catheter is removed if the puncture site shows any signs of infection or the patient is also free of pain without the conduction analgesia. The patient‘s catheter record is closed (date, puncture site findings, motor and sensory findings) and the patient is removed from the current catheter list.