Continuous intercostal nerve blockade for pain relief following cholecystectomy

Efficacy of single-injection unilateral thoracic paravertebral block for post open cholecystectomy pain relief: a prospective randomized study at Gondar University Hospital

Background

Cholecystectomy can be associated with considerable postoperative pain. While the benefits of paravertebral block (PVB) on pain after thoracotomy and mastectomy have been demonstrated, not enough investigations on the effects of PVB on pain after open cholecystectomy have been conducted. We tested the hypothesis that a single-injection thoracic PVB reduces pain scores, decreases opioid consumption, and prolongs analgesic request time after cholecystectomy.

Methods

Of 52 patients recruited, 50 completed the study. They were randomly allocated into two groups: the paravertebral group and the control group. The outcome measures were the severity of pain measured on numeric pain rating scale, total opioid consumption, and first analgesic request time during the first postoperative 24 hours.

Result

The main outcomes recorded during 24 hours after surgery were Numerical Rating Scale (NRS) pain scores (NRS, 0–10), cumulative opioid consumption, and the first analgesic request time. Twenty four hours after surgery, NRS at rest was 4 (3–6) vs 5 (5–7) and at movement 4 (4–7) vs 6 (5–7.5) for the PVB and control groups, respectively. The difference between the groups over the whole observation period was statistically significant (P<0.05). Twenty-four hours after surgery, median (25th–75th percentile) cumulative morphine consumption was 0 (0–2) vs 2.5 (2–4) mg (P<0.0001) and cumulative tramadol consumption was 200 (150–250) mg vs 300 (200–350) mg in the paravertebral and in the control group, respectively (P=0.003). After surgery, the median (25th–75th percentile) first analgesic requirement time was prolonged in the PVB group in statistically significant fashion (P<0.0001).

Conclusion and recommendations

Single-shot thoracic PVB as a component of multi-modal analgesic regimen provided superior analgesia when compared with the control group up to 24 postoperative hours after cholecystectomy, and we recommend this block for post cholecystectomy pain relief.

Common Pitfalls in Anesthesia for Noncardiac Thoracic Surgery

Over the past few decades, major surgical procedures involving the thorax have become commonplace at most larger medical facilities. Advances in perioperative care have allowed surgeons to perform increasingly complex procedures. These procedures are being performed on more seriously ill patients who are at increased risk for significant complications. Recent advances should help the anesthesiologist avoid some of the pitfalls in managing these complex patients. Preoperative assessment aids in the identification of patients at highest risk for intraoperative and postoperative events. Particular attention is given to myasthenia gravis, as thymectomy is among the most common surgical procedures that are performed in these patients. Aggressive pain control techniques, including neuraxial opioids and patient-controlled analgesia, where appropriate, not only improve patient comfort but can improve postoperative pulmonary function. Advances in techniques for providing one-lung ventilation allow the anesthesiologist more options to individualize management for each clinical scenario. Careful fluid management may help to minimize the risk of postoperative pulmonary complications. A basic understanding of video-assisted thoracic surgery should help the anesthesiologist provide optimal surgical conditions and perioperative care. Recent advances demand a greater role for the anesthesiologist if the best outcomes are to be achieved in patients undergoing thoracic procedures.

Management of Pain in the Critically Ill

Analgesia for critically ill patients can be provided most effectively by the use of modern techniques. Under standing of the anatomical pathways for nociceptive sig nal transmission allows the use of techniques that mod ulate or block nociceptive information at several levels (periphery, spinal cord, and systemic). A comprehen sive discussion of analgesic techniques at each level is presented. Formulation of a treatment plan is discussed. Several examples are presented to show the decision- making process for the use of modern analgesic tech niques in critically ill patients.

[Postoperative pain.]

A short survey about the different methods available for producing postoperative analgesia is given, the goal being to make it clear to the clinician that there are quite a number of techniques to be used although the everyday clinical practice often sticks to simple and not too effective methods of pain treatment following surgery. Initially presenting short informations about the neurophysiology of pain and the pathogenesis and causes of postoperative pain two main groups of producing analgesia are then discussed.Thefirst group deals with the systemic use of analgesics be it nonnarcotic analgesic antipyretics or narcotic analgesics (opioids). As for the first subgroup the peripheral action of these drugs (metamizol, acetylsalicylic acid, paracetamol) is brought about by blocking the synthesis of prostaglandins. These substances can only be used for very moderate postoperative pain f.i. following head and neck surgery. The strong acting opioids belong to the second subgroup. Recent informations on receptor sites in the brain and cord and the subgrouping of the receptors throws new light on the understanding of the different effects of these drugs and on the pathomechanisms of agonistic, antagonistic and mixed activities. The clinically used opioids then are mentioned (morphine, fentanyl, methadon, pethidin, piritramide, tilidin, buprenorphin and pentazocine) and dosage, duration of action, antagonisms and untoward side effects are presented. Stress is laid on the recent development of patient-controlled analgesia with all its advantages. Thesecond main group of methods for postoperative analgesia consists of regional anesthesia techniques as there are brachial plexus block, intercostal block and the continuous epidural analgesia using both local anesthetics and spinal opioids. The brachial plexus block in continuous form is absolutely able to prevent pain after operations in the shoulder-arm-region and can be prolonged even for weeks using catheter techniques. The intercostal block on the other hand practically can be performed only as single injection technique being relatively simple however from the technical point of view. The catheter epidural analgesia is the most important method within this group. In comparison to the centrally acting opioids the epidural technique brings some distinct advantages especially in the cardiorespiratory risk case. Choosing between "top up"-technique and continuous infusion of the local anaesthetic depends on the individual circumstances the latter method apparently giving a more steady level of analgesia. The spinal opioid techniques finally gain more and more importance during the last years. They present clear advantages over the local anesthetic methods as there are the long lasting analgesia and the selective blockade of pain not touching motor and sympathetic nerve fibers. A delayed respiratory depression however might be a serious danger showing an incidence of 0,3% in the epidural and some 10% in the subarachnoid route. Aiming to inform the clinician once again about the vast field of possibilities available to make the postoperative course painfree it is hoped that this important task in the postoperative period will be handled with more consequence and effectivity in the future.

Trunk blocks for abdominal surgery

In this review, we discuss the central non-neuraxial regional anaesthesia blocks of the abdomen, including intercostal and intrapleural blocks, rectus sheath and ilioinguinal-iliohypogastric blocks, transversus abdominis plane blocks and paravertebral blocks.

Interpleural block – part 1

Interpleural blockade is effective in treating unilateral surgical and nonsurgical pain from the chest and upper abdomen in both the acute and chronic settings. It has been shown to provide safe, high-quality analgesia after cholecystectomy, thoracotomy, renal and breast surgery, and for certain invasive radiological procedures of the renal and hepatobiliary systems. It has also been used successfully in the treatment of pain from multiple rib fractures, herpes zoster, complex regional pain syndromes, thoracic and abdominal cancer, and pancreatitis. The technique is simple to learn and has both few contra-indications and a low incidence of complications. In the first of two reviews, the authors cover the history, taxonomy and anatomical considerations, the spread of local anaesthetic, and the mechanism of action, physiological, pharmacological and technical considerations in the performance of the block.

Acute pain management of patients with multiple fractured ribs

BACKGROUND

Multiple rib fracture causes severe pain that can seriously compromise respiratory mechanics and exacerbate underlying lung injury and pre-existing respiratory disease, predisposing to respiratory failure. The cornerstone of management is early institution of effective pain relief, the subject of this review.

METHODS

A MEDLINE search was conducted for the years 1966 through and up to December 2002 for human studies written in English using the keywords "rib fractures", "analgesia", "blunt chest trauma", "thoracic injury", and "nerve block". The reference list of key articles was also searched for relevant articles. The various analgesic techniques used in patients with multiple fractured ribs were summarized.

RESULTS

Analgesia could be provided using systemic opioids, transcutaneous electrical nerve stimulation or non steroidal anti-inflammatory drugs. Alternatively, regional analgesic techniques such as intercostal nerve block, epidural analgesia, intrathecal opioids, interpleural analgesia and thoracic paravertebral block have been used effectively. Although invasive, in general, regional blocks tend to be more effective than systemic opioids, and produce less systemic side effects.

CONCLUSION

Based on current evidence it is difficult to recommend a single method that can be safely and effectively used for analgesia in all circumstances in patients with multiple fractured ribs. By understanding the strengths and weaknesses of each analgesic technique, the clinician can weigh the risks and benefits and individualize pain management based on the clinical setting and the extent of trauma.

Thoracic paravertebral analgesia

Thoracic paravertebral nerve blockade, although once widely practised, has now only a few centres which contribute to the literature. Data production has, however, continued and this review correlates this new information with existing knowledge. Its history, taxonomy, anatomy, indications, techniques, mechanisms of analgesia, efficacy, contraindications, toxicity, side effects and complications are reviewed. Thoracic paravertebral analgesia is advocated for surgical procedures of the thorax and abdomen, especially wherever the afferent input is predominantly unilateral eg. thoracotomy, cholecystectomy and nephrectomy. It is also of benefit in the prevention and management of chronic pain. It is a simple undertaking with impressive efficacy. Plasma local anaesthetic levels are acceptable and its side effect and complication rates are low. No mortality has been reported. For unilateral surgery of the chest or truck, thoracic paravertebral analgesia should be considered as the afferent block of choice. For bilateral surgery, its efficacy may be limited by the doses of local anaesthetic which could safely be used and further study in this area in particular is required. This form of afferent blockade deserves greater consideration and investigation.

Haemothorax after attempted intercostal catheterisation

A 30-year-old man with chronic abdominal pain was referred to the Pain Relief Unit after a course of unsuccessful diagnostic blocks and treatments. On admission, history, examination and clinical investigations were consistent with a large pleural effusion due to a recent attempt to catheterise the intercostal space. Pleural drainage confirmed the diagnosis of haemothorax. Percutaneous intercostal nerve blocks are usually considered as safe and simple and no-one to our knowledge has reported such a complication.

[Intrapleural analgesia]

Interpleural analgesia, a recently devised method for postoperative analgesia, consists of the injection of a local anaesthetic into the pleural space. The technique of the catheter insertion is simple and derived from the threadening of an epidural catheter, using the same equipment. An unilateral analgesia is obtained with a rapid onset but not efficient enough for a surgical procedure. The area covered by analgesia includes the thorax and the upper part of the abdomen. No haemodynamic adverse effects occur and ventilatory function is rather improved. The main mechanism of analgesia is probably a retrograde intercostal nerve blockade. Although the exact dose and volume of local anaesthetic is still controversial, 20 to 30 mL of 0.5% bupivacaine is very likely the most convenient. Lidocaine may also be administered at the dose of 2 mg.kg-1 of a 2% solution. Main indications of interpleural analgesia are cholecystectomies and thorax trauma patients. Adverse effects and hazards are uncommon and include mainly pneumothorax and toxic effects of a local anaesthetic overdose.

Analgesic and pulmonary effects of continuous intercostal nerve block following thoracotomy

This study examined the beneficial effects and potential systemic toxicity from continuous intercostal nerve block by repeated bolus injections of bupivacaine. In this double-blind, randomized study, 20 post-thoracotomy patients were assigned to receive four doses of either: 20 ml 0.5% bupivacaine with epinephrine 5 micrograms.ml-1 (bupivacaine group, n = 10), or 20 ml preservative-free saline (placebo group, n = 10) through two indwelling intercostal catheters every six hours. Patients receiving intercostal bupivacaine injections had greater decreases in visual analogue pain scores (VAS) (P less than 0.05) and lower 24 hr morphine requirements, 16.6 +/- 4.6 mg vs 35.8 +/- 7.2 mg, than patients in the placebo group (P less than 0.05). Higher post-injection values of forced expiratory volume in one second, forced vital capacity and peaked expiratory flow rate were also observed in the bupivacaine group (P less than 0.01). Repeated intercostal bupivacaine administration did lead to systemic accumulation, but the peak bupivacaine level after 400 mg was low at 1.2 +/- 0.2 microgram.ml-1. Thus, the technique of continuous intercostal nerve block described in this study is an effective treatment for the control of post-thoracotomy pain.

Wound infiltration with 0.25% bupivacaine not effective for postoperative analgesia after cholecystectomy

The instillation of local anaesthetic agents into surgical wounds has been reported to be an effective method of reducing pain and narcotic requirements, using both local injection and topical application techniques. We performed a double-blind trial to test the value of the long-acting local anaesthetic, bupivacaine, in this role. Eighty patients undergoing elective cholecystectomy were entered into the study. They were divided into 2 groups of 40 patients to compare a local injection technique with a topical application technique. For each route of application, 20 patients received a test solution containing 0.25% plain bupivacaine, and 20 received 0.9% NaCl as a control. Postoperative analgesia in the form of intramuscular pethidine (1-1.5 mg/kg) was made available to all patients on request. The degree of postoperative pain was assessed using three criteria: the time from operation to the first request for analgesia, the total dose of postoperative pethidine required during the first 3 postoperative days and the patient's rating of pain on a 10 cm linear analogue scale at 24 h and 72 h. There was no statistically significant difference between the degree of postoperative pain experienced by patients receiving bupivacaine and those receiving NaCl, when assessed by any criterion. There was also no significant difference found between patients receiving bupivacaine by local infiltration and those receiving the drug topically. It is concluded that the local application of bupivacaine to the wound is not an effective analgesic technique following laparotomy for cholecystectomy.

Analgesia and respiratory function following intrapleural bupivacaine after cholecystectomy

Analgesia and pulmonary function following intrapleural bupivacaine were compared with those following intramuscular pethidine in thirty-four patients after cholecystectomy. The patients were randomly allocated to two groups of seventeen patients each to receive either intrapleural bupivacaine or intramuscular pethidine. The positions of seventeen intrapleural catheters inserted were confirmed by chest radiography. Two out of seventeen catheters were found to be located in the extrapleural space. It was also recognized by fluoroscopy that phrenic nerve palsy did not develop on patients given intrapleural bupivacaine. The subjective quality of analgesia following intrapleural bupivacaine was significantly better than that following intramuscular pethidine. The mean duration of analgesia obtained after each injection of bupivacaine was 4.68 hr (range 3.5-6.1 hr). Forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV 1), which decreased markedly in the postoperative period improved significantly after being given bupivacaine or pethidine. But there was no significant difference in the improvement of FVC and FEV 1, between both groups in spite of the higher percentage of pain relief in the intrapleural bupivacaine group. All respiratory function tests studied thirty days after surgery were not significantly different when compared with those before surgery.

Post-cholecystectomy pulmonary function following interpleural bupivacaine and intramuscular pethidine

Twenty-four patients who were to undergo cholecystectomy were randomised into two groups, one to receive postoperative analgesia with interpleural bupivacaine, 20 ml of a 0.5% solution with adrenaline 5 micrograms/ml, and the other to receive intramuscular pethidine, 1 mg/kg. Preoperative and postoperative pulmonary function, postoperative pain scores, and days from operation to hospital discharge were recorded and statistically compared. There was no significant difference in pain scores, nor in days to discharge; however, postoperative pulmonary mechanics were significantly poorer in the interpleural group. A hypothesis to explain the differences is offered.

Effects of thoracic paravertebral block with bupivacaine versus combined thoracic epidural block with bupivacaine and morphine on pain and pulmonary function after cholecystectomy

Twenty patients undergoing elective cholecystectomy via a subcostal incision were randomized in a double-blind study to either thoracic paravertebral blockade with bupivacaine 0.5% (15 ml followed by 5 ml/h) or thoracic epidural blockade with bupivacaine 7 ml 0.5% + morphine 2 mg followed by 5 ml/h + 0.2 mg/h, respectively for 8 h postoperatively. Mean initial spread of sensory analgesia on the right side was the same (Th3,4-Th11 versus Th2,6-Th11), but decreased (P less than 0.05) postoperatively in the paravertebral group. All patients in the epidural group had bilateral blockade, compared with three patients in the paravertebral group. In both groups only minor insignificant changes in blood pressure and pulse rate were seen postoperatively. Pain scores were significantly higher in the paravertebral group, as was the need for systemic morphine (P less than 0.05). Pulmonary function estimated by forced vital capacity, forced expiratory volume and peak expiratory flow rate decreased about 50% postoperatively in both groups. In conclusion, the continuous paravertebral bupivacaine infusion used here was insufficient as the only analgesic after cholecystectomy. In contrast, epidural blockade with combined bupivacaine and low dose morphine produced total pain relief in six of ten patients.

Thoracic paravertebral block: a method of pain control

The adverse effects of pain on acutely ill or traumatized patients are well documented. A variety of pain-relieving techniques are now available to meet the varied requirements for pain relief. This paper presents the results of a single, large-volume injection of bupivacaine 0.5% in the thoracic paravertebral space, achieving pain relief over several thoracic dermatomes in patients with respiratory compromise secondary to thoracic or upper abdominal injury. The block proved quick and simple to perform, with excellent clinical results of long duration and virtually no complications. Although not previously described, this single, large-volume injection approach to achieving an extensive thoracic paravertebral block may well become an important pain management technique in appropriate patients.

Therapeutic progress--review XXXI. Therapeutic progress in intensive care sedation and analgesia. Part II--Drug selection

In part I of this review the principles governing the uses of analgesics and sedatives in the ITU were considered. In part II we shall review the drugs available considering first, symptomatic therapy and secondly, regional analgesia.

Intercostal catheterisation. An alternative approach to the paravertebral space

Twenty-one patients scheduled to undergo thoracotomy or median sternotomy had intercostal catheters inserted pre-operatively. During thoracotomy, under direct vision, the spread of 20 ml of a solution containing bupivacaine and methylene blue was followed. In most cases the spread involved one or two intercostal spaces. However, in all but one patient, dye spread medially to the paravertebral space where it then spread in both caudad and cephalad directions to reach between two and five vertebrae. In three cases, dye was seen crossing the anterior surface of the vertebrae to reach the contralateral aspect. It is concluded that a major component of dermatomal block during intercostal catheterisations may be secondary to paravertebral spread.

Postoperative analgesia with intrapleural administration of bupivacaine-adrenaline

Twenty-one patients who underwent elective cholecystectomy were studied with regard to the effect of intrapleural administration of bupivacaine-adrenaline solution on postoperative pain and ventilatory capacity. Administration of 10 or 20 ml of 2.5 mg/ml or 5 mg/ml bupivacaine solution resulted in complete analgesia in 143 of 159 administrations. Most patients experienced the maximal pain-relieving effect within 1-2 min and analgesia persisted as a rule for 3-5 h. Forced vital capacity and forced expiratory volume in 1 s increased after intrapleural analgesia on average by 56% and 46%, respectively, on the first postoperative day and by 35% and 51%, respectively, on the second day. There was no significant difference in the analgesic effect or in the effect on the ventilatory capacity between the 2.5 mg/ml or the 5 mg/ml solution, in either the 10 ml or the 20 ml dose. Placebo (NaCl) given intrapleurally had no effect on pain or on the ventilatory capacity. The plasma concentration of bupivacaine after intrapleural administration showed a wide interindividual variation, with considerably higher average values when the 5 mg/ml solution had been used than for the 2.5 mg/ml solution. Although no toxic effects were noted, a 2.5 mg/ml solution, which can be given in an initial dose of 20 ml and top-up doses of 10 ml at 3-6 h intervals, is recommended. In four patients minor pneumothorax developed when the catheter was introduced. The pneumothorax was easily evacuated, but underlines the need for great care when introducing the catheter.

Multiple intercostal blocks by a single injection? A clinical and radiological investigation

Three different techniques for producing multiple intercostal nerve blocks using bupivacaine were compared in volunteers. The techniques used were multiple injections at intercostal nerves 7-11, or a single injection employing a needle or a catheter inserted in the 9th intercostal space. The injections were made at the costal angle. The anatomical spread of a mixture of a local anaesthetic and a radio-opaque fluid following the single injection technique at the ninth intercostal space or at the subcostal space was evaluated by computerized x-ray tomography (CT). The distribution of cutaneous analgesia/hypalgesia following all techniques was evaluated by pin prick. No spread of the local anaesthetic to adjacent intercostal spaces or to the paravertebral space could be shown by CT. The distribution of cutaneous analgesia was limited to three segments or less following a single injection. No difference in blood levels of bupivacaine could be found. It is concluded that the single injection technique of producing multiple intercostal nerve blocks is inferior to the multiple injection technique.