Neurophysiologic assessment of nerve impairment in posterolateral and muscle-sparing thoracotomy

Chronic Postsurgical Pain Following Lung Transplantation: Characteristics, Risk Factors, Treatment, and Prevention: A Narrative Review

Chronic pain after lung transplantation (LTx) can substantially reduce quality of life (QoL), yet current consensus guidelines say little about how to prevent or manage it. Research on pain after LTx has tended to focus on acute rather than chronic pain, and it has not extensively examined the factors associated with onset or resolution of chronic pain, which differ from factors influencing chronic pain after general thoracic surgery. This narrative review explores what is known about the epidemiology and risk factors of chronic pain after LTx, as well as effective ways to treat or prevent it. The review identifies key questions and issues that should be the focus of future research.

Effects of Ultrasound-Guided Thoracic Paravertebral Nerve Block Combined with Perineural or IV Dexmedetomidine on Acute and Chronic Pain After Thoracoscopic Resection of Lung Lesions: A Double-Blind Randomized Trial

Background

Thoracic paravertebral block (TPVB) analgesia can be prolonged by local anesthetic adjuvants such as dexmedetomidine. This study aimed to evaluate the two administration routes of dexmedetomidine on acute pain and chronic neuropathic pain (NeuP) prevention compared with no dexmedetomidine.

Methods

A total of 216 patients were randomized to receive TPVB using 0.4% ropivacaine alone (R Group), with perineural dexmedetomidine 0.5 μg·kg-1 (RD0.5 Group) or 1.0 μg·kg-1 (RD1.0 Group), or intravenous (IV) dexmedetomidine 0.5 μg·kg-1·h-1 (RDiv Group). The primary outcome was the incidence of chronic NeuP, defined as a Leeds Assessment of Neuropathic Symptoms and Signs (LANSS) pain score > 12 points at 3-month after surgery.

Results

(1) For the primary outcome, RD0.5 Group and RD1.0 Group demonstrated a decreased incidence of chronic NeuP at 3-month after surgery; (2) Compared with R Group, RDiv Group, RD0.5 Group, and RD1.0 Group can reduce VAS scores at rest and movement and Prince-Henry Pain scores at 12 and 24-h after surgery, the consumption of oral morphine equivalent (OME) and improve QOD-15 at POD1; (3) Compared with RDiv Group, RD0.5 Group and RD1.0 Group can reduce VAS scores at rest and movement and Prince-Henry Pain scores at 12 and 24-h after surgery, the consumption of postoperative OME and improve QOD-15 at POD1; (4) Compared with RD0.5 Group, RD1.0 Group effectively reduced VAS scores at rest at 12 and 24-h after surgery, VAS scores in movement and Prince-Henry Pain scores at 12-h after surgery. However, RD1.0 Group showed an increased incidence of drowsiness.

Conclusion

Perineural or IV dexmedetomidine are similarly effective in reducing acute pain, but only perineural dexmedetomidine reduced chronic NeuP. Moreover, considering postoperative complications such as drowsiness, perineural dexmedetomidine (0.5 μg·kg-1) may be a more appropriate choice.

Clinical Trial Registration

Chinese Clinical Trial Registry (ChiCTR2200058982).

Additive value of superficial parasternal intercostal plane block and serratus anterior plane block in lung transplantation surgery: a retrospective exploratory study

BACKGROUND

Adequate pain control following lung transplantation (LTx) surgery is paramount. Thoracic epidural analgesia (TEA) is the gold standard; however, the potential use of extracorporeal membrane oxygenation (ECMO) and consequent anticoagulation therapy raises safety concerns, prompting clinicians to seek safer alternatives. The utility of thoracic wall blocks in general thoracic surgery is well established; however, their role in the context of LTx has been poorly investigated.

METHODS

In this retrospective exploratory study, we assessed the effect of adding a superficial parasternal intercostal plane (sPIP) block and serratus anterior plane (SAP) block to standard anesthetic and analgesic care on tracheal extubation rates, pain scores and opioid consumption until 72 hours postoperatively in LTx.

RESULTS

Sixty patients were included in the analysis; 35 received the standard anesthetic and analgesic care (control group), and 25 received sPIP and SAP blocks in addition to the standard anesthetic and analgesic care (intervention group). We observed higher tracheal extubation rates in the intervention group at 8 hours postoperatively (16.0% vs 0.0%, p=0.03). This was also shown after adjusting for known prognostic factors (OR 1.18; 95% CI 1.04 to 1.33, p=0.02). Furthermore, we noted a lower opioid consumption measured by morphine milligram equivalents at 24 hours in the intervention group (median 405 (IQR 300-490) vs 266 (IQR 168-366), p=0.02). This was also found after adjusting for known prognostic factors (β -118; 95% CI -221 to 14, p=0.03).

CONCLUSION

sPIP and SAP blocks are safe regional analgesic techniques in LTx involving ECMO and clamshell incision. They are associated with faster tracheal extubation and lower opioid consumption. These techniques should be considered when TEA is not appropriate. Further high-quality studies are warranted to confirm these findings.

Regional analgesia for lung transplantation: A narrative review

Lung transplantation (LTx) is the definitive treatment for end-stage pulmonary disease. About 4500 LTxs are performed annually worldwide. It is considered challenging and complex surgery regarding anaesthesia and pain management. While providing adequate analgesia is crucial for patient comfort, early mobilisation and prevention of postoperative pulmonary complications, standardising an analgesic protocol is challenging due to the diversity of aetiologies, surgical approaches and the potential use of extracorporeal life support (ECLS). Although thoracic epidural analgesia is commonly considered the gold standard, concerns regarding procedural safety and its potential for devastating consequences have led physicians to seek safer analgesic modalities such as thoracic nerve blocks. The advantages of thoracic nerve blocks for general thoracic surgery are well established. However, their utility in LTx remains unclear. Considering paucity of relevant literature, this review aims to raise awareness about the literature gap in the field and highlight the need for further high-quality studies determining the effectiveness of available techniques.

Prevalence and Characteristics of Persistent Postoperative Pain After Thoracic Surgery: A Systematic Review and Meta-Analysis

BACKGROUND

A systematic review and meta-analysis was conducted to investigate the prevalence and characteristics of persistent (≥3 months) postoperative pain (PPP) after thoracic surgery.

METHODS

For this purpose, Medline, Embase, and CINAHL databases were searched for the prevalence and characteristics of PPP after thoracic surgery from their inception to May 1, 2022. Random-effect meta-analysis was used to estimate pooled prevalence and characteristics.

RESULTS

We included 90 studies with 19,001 patients. At a median follow-up of 12 months, the pooled overall prevalence of PPP after thoracic surgery was 38.1% (95% confidence interval [CI], 34.1-42.3). Among patients with PPP, 40.6% (95% CI, 34.4-47.2) and 10.1% (95% CI, 6.8-14.8) experienced moderate-to-severe (rating scale ≥4/10) and severe (rating scale ≥7/10) PPP, respectively. Overall, 56.5% (95% CI, 44.3-67.9) of patients with PPP required opioid analgesic use, and 33.0% (95% CI, 22.5-44.3) showed a neuropathic component.

CONCLUSIONS

One in 3 thoracic surgery patients developed PPP. There is a need for adequate pain treatment and follow-up in patients undergoing thoracic surgery.

Comparison of Chronic Postsurgical Pain Between Single-Port and Multi-Port Video-Assisted Thoracoscopic Pulmonary Resection: A Prospective Study

Background  Little is known about the prevalence of chronic postsurgical pain (CPSP) among patients receiving single-port video-assisted thoracic surgery (SP-VATS) compared with those undergoing multi-port VATS (MP-VATS). This study aimed to compare the incidence of CPSP between SP-VATS and MP-VATS lung resection and assess how the pain affected the daily living activities of this patient population.

Methods  We prospectively collected data regarding the demographic features, clinical factors during surgery, the intensity of acute postoperative pain, and complications after surgery among patients receiving elective SP-VATS or MP-VATS lung resection at our institution between June 2015 and August 2018. At 3-, 6-, and 12-months following surgery, the patients were followed up through a telephonic interview. The Brief Pain Inventory-Short Form was adopted to assess the incidence, severity and location of the CPSP, analgesic consumption, as well as the interference of pain with daily activities.

Results  In total, 476 patients were screened for eligibility, 411 patients were followed up for 12 months and included in final analysis. Among these, 190 patients had undergone an SP-VATS pulmonary resection and 221 had an MP-VATS pulmonary resection. At both 3 and 6 months, the incidence of CPSP in the SP-VATS group was lower than that in the MP-VATS group (25.3 vs. 38.0%, p  = 0.006; 11.1 vs. 19.0%, p  = 0.026, respectively). At 12 months after surgery, the prevalence of CPSP was comparable between groups (4.7 vs, 9.0%, p  = 0.089). In addition, the SP-VATS technique alleviated pain interference with the daily living activities of patients with CPSP in several domains, including sleep, mood, and enjoyment of life compared with the MP-VATS technique. The two predictive factors for CPSP at postoperative 3 months were the MP-VATS technique (odds ratio [OR] = 1.792, p  = 0.019) and postoperative chemotherapy (OR = 1.718, p  = 0.033).

Conclusions  This study indicated that the SP-VATS technique reduced the prevalence of CPSP at 3- and 6-months post-pulmonary resection compared with the MP-VATS technique. The SP-VATS technique also significantly alleviated pain interference with the daily living activities of the patients.

Intramuscular stimulation as a new modality to control postthoracotomy pain: A randomized clinical trial

OBJECTIVE

Postoperative pain after thoracic surgery primarily hinders patients' mobility, decreasing the quality of life. To date, various modalities have been suggested to improve postoperative pain. However, pain alleviation still remains a challenge, resulting in continued reliance on opioids. To tackle this problem, this study introduces a needle electrical twitch obtaining intramuscular stimulation (NETOIMS) as a new effective treatment modality for postoperative pain after thoracoscopic surgery.

METHODS

This randomized clinical trial analyzed patients receiving video-assisted thoracoscopic surgery pulmonary resection between March 2018 and June 2020 at a single institution. A total of 77 patients (NETOIMS, 36; intravenous patient-controlled analgesia, 41) were included. NETOIMS was conducted on the retracted intercostal muscle immediately following the main procedure, just before skin closure. Postoperative pain (numeric rating scale) and oral opioid morphine milligram equivalent were assessed daily until postoperative day 5.

RESULTS

The NETOIMS group had a significantly lower numeric rating scale score on postoperative day (POD) 0 (P < .01), POD2 (P < .001), POD4 (P < .001), and POD5 (P = .01). The predicted time to complete pain resolution was 6.15 days in the NETOIMS group and 20.7 days in the intravenous patient-controlled analgesia group. The oral opioid morphine milligram equivalent was significantly lower in the NETOIMS group on POD0 (P < .001) and POD1 (P < .001).

CONCLUSIONS

NETOIMS appears to be an effective modality in alleviating postoperative pain after thoracoscopic surgery, thereby reducing the reliance on opioid use.

AAAPT Diagnostic Criteria for Acute Thoracic Surgery Pain

Patients undergoing thoracic surgery experience particular challenges for acute pain management. Availability of standardized diagnostic criteria for identification of acute pain after thoracotomy and video assisted thoracic surgery (VATS) would provide a foundation for evidence-based management and facilitate future research. The Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks (ACTTION) public-private partnership with the United States Food and Drug Administration, the American Pain Society (APS), and the American Academy of Pain Medicine (AAPM) formed the ACTTION-APS-AAPM Pain Taxonomy (AAAPT) initiative to address absence of acute pain diagnostic criteria. A multidisciplinary working group of pain experts was invited to develop diagnostic criteria for acute thoracotomy and VATS pain. The working group used available studies and expert opinion to characterize acute pain after thoracotomy and VATS using the 5-dimension taxonomical structure proposed by AAAPT (i.e., core diagnostic criteria, common features, modulating factors, impact/functional consequences, and putative mechanisms). The resulting diagnostic criteria will serve as the starting point for subsequent empirically validated criteria. PERSPECTIVE ITEM: This article characterizes acute pain after thoracotomy and VATS using the 5-dimension taxonomical structure proposed by AAAPT (ie, core diagnostic criteria, common features, modulating factors, impact and/or functional consequences, and putative mechanisms).

Jerks of the latissimus dorsi muscle and intercostal neuralgia after posterolateral thoracotomy

Introduction

Post-thoracotomy pain syndrome (PTPS) is a common complication related to intercostal nerve injury. During this type of surgery, although less frequently, thoracodorsal and long thoracic nerves can also be injured, and jerks of peripheral origins may appear. We report a case with intercostal neuralgia and latissimus dorsi muscle jerks after posterolateral thoracotomy.

Case report

A 55-year-old woman with Ehlers-Danlos Syndrome presented with a typical picture of PTPS along the right T5 dermatome following posterolateral thoracotomy at the level of the fifth intercostal space. Approximately six months after the surgery she developed frequent jerk-like involuntary movements of the right latissimus dorsi muscle. Neuropathic pain along the T5 dermatome was partially relieved with thoracic epidural block. No special attention was paid to the jerks until three years later. A neurophysiological study demonstrated a peripheral origin of these movements and the patient was then treated with periodic injections of botulinum toxin. In response, involuntary movements of the latissimus dorsi muscle disappeared.

Significance

To our knowledge, this is the first case with PTPS and post-thoracotomy latissimus dorsi muscle jerks in a patient with Ehlers-Danlos Syndrome. A correct diagnosis together with identification of iatrogenic neuropathic disorders allow the delivery of targeted treatments. In such cases clinical neurophysiology helps to determine a correct diagnosis.

Neural Selective Cryoneurolysis with Ice Slurry Injection in a Rat Model

BACKGROUND

Postoperative pain caused by trauma to nerves and tissue around the surgical site is a major problem. Perioperative steps to reduce postoperative pain include local anesthetics and opioids, the latter of which are addictive and have contributed to the opioid epidemic. Cryoneurolysis is a nonopioid and long-lasting treatment for reducing postoperative pain. However, current methods of cryoneurolysis are invasive, technically demanding, and are not tissue-selective. This project aims to determine whether ice slurry can be used as a novel, injectable, drug-free, and tissue-selective method of cryoneurolysis and resulting analgesia.

METHODS

The authors developed an injectable and selective method of cryoneurolysis using biocompatible ice slurry, using rat sciatic nerve to investigate the effect of slurry injection on the structure and function of the nerve. Sixty-two naïve, male Sprague-Dawley rats were used in this study. Advanced Coherent anti-Stokes Raman Scattering microscopy, light, and fluorescent microscopy imaging were used at baseline and at various time points after treatment for evaluation and quantification of myelin sheath and axon structural integrity. Validated motor and sensory testing were used for evaluating the sciatic nerve function in response to ice slurry treatment.

RESULTS

Ice slurry injection can selectively target the rat sciatic nerve. Being injectable, it can infiltrate around the nerve. The authors demonstrate that a single injection is safe and selective for reversibly disrupting the myelin sheaths and axon density, with complete structural recovery by day 112. This leads to decreased nocifensive function for up to 60 days, with complete recovery by day 112. There was up to median [interquartile range]: 68% [60 to 94%] reduction in mechanical pain response after treatment.

CONCLUSIONS

Ice slurry injection selectively targets the rat sciatic nerve, causing no damage to surrounding tissue. Injection of ice slurry around the rat sciatic nerve induced decreased nociceptive response from the baseline through neural selective cryoneurolysis.

Post-Thoracotomy Pain: Current Strategies for Prevention and Treatment

Treating acute pain after thoracotomy surgery and preventing the development of chronic post-thoracotomy pain syndrome (PTPS) remain significant challenges in this surgical population. While appropriately treated acute thoracotomy pain often resolves, a significant number of patients develop PTPS, with up to 65% of patients experiencing some pain and 10% suffering life-altering, debilitating pain. Currently, there is very little known about specific molecular targets or novel therapeutic combinations that effectively prevent PTPS. Identifying modifiable clinical risk factors (procedure, physical and mental health, preoperative pain in the surgical area and another regions) seems to the most pragmatic approach for prevention for now. Effective acute pain management adopting a multimodal approach can result in a decreased incidence of PTPS. Interventional techniques such as paraverterbral blocks, intercostal blocks, and erector spinae blocks show some promise as well. Future research should be focused on minimally invasive surgeries and also the effect of ERAS protocols, including early mobilization, nutrition, and early removal of drains, on the development of PTPS.

Neuropathic Pain: From Mechanisms to Treatment

Neuropathic pain caused by a lesion or disease of the somatosensory nervous system is a common chronic pain condition with major impact on quality of life. Examples include trigeminal neuralgia, painful polyneuropathy, postherpetic neuralgia, and central poststroke pain. Most patients complain of an ongoing or intermittent spontaneous pain of, for example, burning, pricking, squeezing quality, which may be accompanied by evoked pain, particular to light touch and cold. Ectopic activity in, for example, nerve-end neuroma, compressed nerves or nerve roots, dorsal root ganglia, and the thalamus may in different conditions underlie the spontaneous pain. Evoked pain may spread to neighboring areas, and the underlying pathophysiology involves peripheral and central sensitization. Maladaptive structural changes and a number of cell-cell interactions and molecular signaling underlie the sensitization of nociceptive pathways. These include alteration in ion channels, activation of immune cells, glial-derived mediators, and epigenetic regulation. The major classes of therapeutics include drugs acting on α₂δ subunits of calcium channels, sodium channels, and descending modulatory inhibitory pathways.

Chronic Pain After Lung Transplantation and Its Impact on Quality of Life: A 4-Year Follow-up

Aiming to investigate the prevalence of chronic pain and its impact on quality of life of lung transplantation (LTx) recipients, we performed a transversal study collecting data using a standard interview model in 2 different periods: first, in 2016 we studied LTx recipients after 3 to 11 months of the transplantation; and second, in 2019, we studied the same patients after 39 to 55 months of transplantation surgery. The chosen questionnaires were the Brief Pain Inventory and Short-Form Health Survey. Chronic pain was identified in 47.2% of the analyzed recipients at the initial interview and in 40.7% at the second evaluation. In both periods, the domain quality of life was the most affected in contrast to functional capacity, which was the least affected. On the first analysis, a moderate negative correlation was found between pain intensity and functional capacity domains (-0,42/P = .010), pain (-0,46/P = .005), and mental health (-047/P = .004); meanwhile, the second survey showed a moderate/high negative correlation for most of the domains, except for the mental health (-0,036/P = .120). We conclude that the prevalence of chronic pain after LTx is high, and the pain intensity had a moderate negative correlation with domains such functional capacity, mental health, and pain at the first analysis in contrast to the moderate/high negative correlation for almost every domain, except mental health, at the second analysis.

Post-thoracotomy pain syndrome: seldom severe, often neuropathic, treated unspecific, and insufficient

Background:

Post-thoracotomy pain syndrome (PTPS) is reported with a prevalence ranging between 33% and 91% in literature. However, the difference between open (TT) and video-assisted thoracic surgery (VATS) concerning the prevalence and neuropathic character of PTPS has not yet been systematically investigated. Furthermore, knowledge on analgesic treatment and its efficacy is limited.

Methods:

Structured telephone interviews were conducted with 488 patients 6 to 30 months after TT and VATS. In case of pain, patients received a structured questionnaire including the Leeds Assessment of Neuropathic Symptoms and Signs and Brief Pain Inventory.

Results:

Prevalence of PTPS was 28.6%. 13.2% of patients had a pain intensity Numeric Rating Scale >3, and 4.6% of patients had a pain intensity Numeric Rating Scale >5. In case of PTPS, 63% of patients suffered from neuropathic pain. Post-thoracotomy pain syndrome was more frequent after TT than after VATS (38.0% vs 29.3%, P < 0.05) and in patients younger than 65 years (42.3% vs 26.4%; P < 0.05). TT resulted more often in neuropathic pain (67.7% vs 43.9%; P < 0.05). Forty six percent of PTPS patients received analgesics: 30.3% nonopioids, 25.2% opioids, 10.9% anticonvulsants, and 1.7% antidepressants. Antineuropathic agents were used in 17.4% of patients with neuropathic pain. In 36.7% of patients, the reported reduction of pain was less than 30.0%.

Conclusions:

Post-thoracotomy pain syndrome is not as common as estimated. In most cases, pain intensity is moderate, but patients suffering from severe pain require special attention. They are often heavily disabled due to pain. Tissue-protecting surgery like VATS is beneficial for the prevention of PTPS. Analgesic medications are often underdosed, unspecific for neuropathic pain, and insufficient.

Effect of Transcranial Direct Current Stimulation Combined With Patient-Controlled Intravenous Morphine Analgesia on Analgesic Use and Post-Thoracotomy Pain. A Prospective, Randomized, Double-Blind, Sham-Controlled, Proof-of-Concept Clinical Trial

BACKGROUND

Transcranial direct current stimulation (tDCS) is used for various chronic pain conditions, but experience with tDCS for acute postoperative pain is limited. This study investigated the effect of tDCS vs. sham stimulation on postoperative morphine consumption and pain intensity after thoracotomy.

METHODS

This is a single-center, prospective, randomized, double-blind, sham-controlled trial in lung cancer patients undergoing thoracotomy under general anesthesia. All patients received patient-controlled (PCA) intravenous morphine and intercostal nerve blocks at the end of surgery. The intervention group (a-tDCS, n = 31) received anodal tDCS over the left primary motor cortex (C3-Fp2) for 20 min at 1.2 mA, on five consecutive days; the control group (n = 31) received sham stimulation. Morphine consumption, number of analgesia demands, and pain intensity at rest, with movement and with cough were recorded at the following intervals: immediately before (T1), immediately after intervention (T2), then every hour for 4 h (Т3-Т6), then every 6 h (Т7-Т31) for 5 days. We recorded outcomes on postoperative days 1 and 5 and conducted a phone interview inquiring about chronic pain 1 year later (NCT03005548).

RESULTS

A total of 62 patients enrolled, but tDCS was prematurely stopped in six patients. Fifty-five patients (27 a-tDCS, 28 sham) had three or more tDCS applications and were included in the analysis. Cumulative morphine dose in the first 120 h after surgery was significantly lower in the tDCS [77.00 (54.00-123.00) mg] compared to sham group [112.00 (79.97-173.35) mg, p = 0.043, Cohen's d = 0.42]. On postoperative day 5, maximum visual analog scale (VAS) pain score with cough was significantly lower in the tDCS group [29.00 (20.00-39.00) vs. 44.50 (30.00-61.75) mm, p = 0.018], and pain interference with cough was 80% lower [10.00 (0.00-30.00) vs. 50.00 (0.00-70.00), p = 0.013]. One year after surgery, there was no significant difference between groups with regard to chronic pain and analgesic use.

CONCLUSION

In lung cancer patients undergoing thoracotomy, three to five tDCS sessions significantly reduced cumulative postoperative morphine use, maximum VAS pain scores with cough, and pain interference with cough on postoperative day 5, but there was no obvious long-term benefit from tDCS.

Rectus abdominis muscle atrophy after thoracotomy

Intercostal nerve injury is known to occur during thoracotomy; however, rectus abdominis muscle atrophy has rarely been reported. We describe a 52-year-old man who underwent primary closure of esophageal perforation and lung decortication via left thoracotomy. He was discharged 40 days postoperatively without any complications. He noticed an abdominal bulge 2 months later, and computed tomography revealed left rectus abdominis muscle atrophy. We report thoracotomy induced denervation causing rectus abdominis muscle atrophy.

Retraction mechanics of Finochietto-style self-retaining thoracic retractors

OBJECTIVES

Analyze the mechanics of Finochietto-style retractors, including the responses of thoracic tissues during thoracotomy, with an emphasis on tissue trauma and means for its reduction.

METHODS

Mechanical analyses of the retractor were performed, including analysis of deformation under load and kinematics of the crank mechanism. Thoracotomies in a porcine model were performed in anesthetized animals (7) and fresh cadavers (17) using an instrumented retractor.

RESULTS

Mechanical analyses revealed that arm motion is a non-linear function of handle rotation, that deformation of the retractor under load concentrates force at one edge of the retractor blade, and that the retractor behaves like a spring, deforming under the load of retraction and continuing to force open the incision long after crank rotation stops. Experimental thoracotomies included retractions ranging from 50 to 112 mm over 30 to 370 s, generating maximum forces of 118 to 470 N (12-50 kgf). Tissue ruptures occurred in 12 of the 24 retractions. These ruptures all occurred at retraction distances wider than 30 mm and at forces greater than 122.5 N. Significant tissue ruptures were observed for nearly all retractions at higher retraction rates (exceeding ½ rotation of the crank per 10 s).

CONCLUSIONS

The Finochietto-style retractor can generate large forces and some aspects of its design increase the probability of tissue trauma.

Chronic pain after bilateral thoracotomy in lung transplant patients

Background and aims

The relative contribution of patient-related factors and intraoperative nerve damage for the development of chronic pain after surgery is unclear. This study aimed to examine chronic pain after bilateral thoracotomy. We hypothesized, that individual patient-related risk factors would be important resulting in an intraindividual uniformity of pain and hyperphenomena between the two sides of the thorax.

Methods

Twenty patients who had undergone lung transplantation via bilateral thoracotomy 6–12 months previously were included from the Danish Lung Transplant program, Rigshospitalet, Denmark, from October 2016 to August 2017. All patients answered questionnaires about pain in and around the scar, completed the Neuropathic Pain Symptom Inventory, and underwent bedside examination for hyperphenomena (brush- and cold-evoked allodynia, pinprick hyperalgesia) and pinprick hypoalgesia.

Results

Nine patients reported spontaneous pain bilaterally, five patients had pain on one side only, and six patients had no pain. Hyperphenomena were present on both sides of the thorax in 13 patients, on one side in four patients, and three patients had no hyperphenomena. The intraindividual uniformity of pain (p=0.029) and hyperphenomena (p=0.011) between the two sides of the thorax suggests that patient-related factors play an important role in the development of chronic pain.

Conclusions

The results of the present study provide support for the hypothesis of an individual predisposition for the development of chronic pain after thoracotomy.

Implications

Patient-related risk factors contribute to the development of chronic pain after thoracotomy. This result most likely can be transferred to chronic pain after other surgical procedures and therefore help us understand risk factors for chronic pain after surgery.

Intercostal Neurolysis for The Treatment of Postsurgical Thoracic Pain: a Case Series

INTRODUCTION

We investigated the possible role of intercostal surgical neurolysis in relieving chronic neuropathic pain refractory to other nonsurgical treatments in patients with postsurgical thoracic pain.

METHODS

We retrospectively collected clinical data on patients referred to the Neurosurgery Unit of Policlinic Hospital of Milan. Ten patients (age range, 20-68 years) suffering from neuropathic pain for at least 2 months after thoracic surgery underwent intercostal neurolysis.

RESULTS

Compared with preneurolysis, pain intensity decreased 1 month postneurolysis and remained stable 2 months postneurolysis (median score [interquartile range]: 8 [6-9] preneurolysis, 4 [3-5] 1 month after, and 3 [2-5] 2 months after, P < 0.001). Antiepileptic drugs for pain control decreased after neurolysis.

DISCUSSION

Surgical intercostal neurolysis may be a promising therapeutic option in patients with chronic neuropathic pain associated with neurological deficits. Muscle Nerve 58: 671-675, 2018.

From acute to chronic pain after thoracic surgery: the significance of different components of the acute pain response

Purpose

Acute postoperative pain is a strong predictor for postthoracotomy pain syndrome (PTPS), but the mechanism is unknown. Even though thoracic pain is usually considered the dominating acute pain after thoracic surgery, up to 45% of patients consider shoulder pain to be dominating pain and often this shoulder pain is referred visceral pain. This study aims to examine which components of the acute pain response after thoracic surgery were associated with PTPS and if any signs of a generalized central hypersensitivity could be identified in patients with PTPS.

Patients and methods

In a prospective cohort study, 60 consecutive patients for lobectomy were included and examined preoperatively and 12 months postoperatively for pain and signs of hypersensitivity using a comprehensive protocol for quantitative sensory testing. Thoracic pain, shoulder pain, referred pain, and overall pain were assessed five times daily during the first four postoperative days.

Results

Sixteen patients (31% of the 52 patients who completed the study) developed PTPS. Thoracic pain was the only pain component that was associated with PTPS and was a stronger predictor for PTPS than overall pain. There were no signs of hypersensitivity before or after the operation in patients with PTPS, but patients with PTPS more often suffered from preoperative pain.

Conclusion

Thoracic pain was the only component of the acute pain response that predicted PTPS and was a stronger predictor than overall pain.

MUSCLE-SPARING VERSUS STANDARD POSTEROLATERAL THORACOTOMY IN NEONATES WITH ESOPHAGEAL ATRESIA

Background:

The muscle-sparing thoracotomy (MST) has not yet been thoroughly studied and assessed in comparison to the traditional thoracotomy method in newborns.

Aim:

To compare the outcomes of MST and standard posterolateral thoracotomy (PLT) in newborns.

Methods:

Randomized, controlled, double-blind trial on 40 neonates with esophageal atresia, comparing the time of beginning a surgery until seeing the pleura, the duration of hospitalization in the neonatal intensive care unit, the time in ventilator, the time of returning the shoulder function, the time of returning the Moro reflex, and the mortality between the two techniques.

Results:

The data showed no differences between the two groups in basic information (weight, height, gender, numbers of prematurity neonates and caesarean). The results on the size of the scar in the MST group was significantly lower than in the PLT group. Also, the time of returning the shoulder function in MST group was earlier than in PLT group. There were no significant differences in the duration since the beginning the surgery to see the pleura, the time of being hospitalized in intensive unit, the time that the infant required ventilator, returning time of the Moro reflex in 1^st and 3^rd months after the operation, and the mortality rates between MST and PLT groups.

Conclusion:

It seems that the advantages of using MST over PLT procedure in neonates include the earlier shoulder function recovery and also superior cosmetic results.

Influence of Regional Anesthesia on the Rate of Chronic Postthoracotomy Pain Syndrome in Lung Cancer Patients

Purpose: Our study aimed to assess whether the type of regional anesthesia influenced the incidence of chronic postthoracotomy pain syndrome (CPTPS).

Methods: This was a prospective, randomized study that included 300 patients undergoing lung cancer resection using thoracotomy. They were randomized into three groups: paravertebral nerve block (PVB), thoracic epidural anesthesia (TEA), and intercostal nerve block (INB). General anesthesia was similar in the groups. A horizontal visual analogue scale (VAS) was used to assess the intensity of the pain syndrome. It was assessed and recorded 7 days, 1 month, and 6 months after surgery.

Results: At 6 months after surgery, the incidence (p <0.05) of the CPTPS was higher in the INB group (40%) than in the TEA group (23%). The CPTPS frequency in the PVB group did not differ from the other groups (34%).

Conclusion: The use of the TEA in patients who underwent open lung cancer surgery contributed to a significant decline in the CPTPS frequency compared to patients who were administered INB. Using PVB did not decrease the CPTPS frequency.

Comprehensive Acute Pain Management in the Perioperative Surgical Home

The careful coordination of care throughout the perioperative continuum offered by the perioperative surgical home (PSH) is important in the treatment of postoperative pain. Physician anesthesiologists have expertise in acute pain management, pharmacology, and regional and neuraxial anesthetic techniques, making them ideal leaders for managing perioperative analgesia within the PSH. Severe postoperative pain is one of many patient- and surgery-specific factors in the development of chronic postsurgical pain. Delivering adequate perioperative analgesia is important to avoid this development, to decrease perioperative morbidity, and to improve patient satisfaction.

Paralysis of the Rectus Abdominis Muscle after a Video-Assisted Thoracoscopic Surgery

The rectus abdominis muscle is innervated by intercostal nerves T7-T12, and most thoracotomies are performed through the fourth to sixth intercostal spaces, so direct nerve damage to the rectus abdominis seems unlikely. However, at least one trocar is inserted below the seventh intercostal space in most multi-port video-assisted thoracoscopic surgeries (VATSs), and injury of the seventh or lower intercostal nerve with related paralysis of the rectus abdominis is possible, albeit rare. Only two cases of rectus abdominis paralysis caused by after VATSs have been reported, and these cases were not permanent injuries. This is the first report of permanent paralysis of the rectus abdominis after VATSs.

A novel muscle-sparing high thoracotomy for upper thoracic spine resection and reconstruction

PURPOSE

High thoracotomy allows access to the anterior cervicothoracic and upper thoracic vertebrae; however, traditional techniques transect shoulder girdle muscles, leading to postoperative shoulder dysfunction. Muscle-sparing techniques diminish this concern, but often sacrifice the quality of exposure. We describe a novel muscle-sparing, high thoracotomy approach for the treatment of ventral cervicothoracic and upper thoracic spine lesions.

METHODS

A novel muscle-sparing, high thoracotomy approach is described, utilizing a midline posterior incision with lateral extension from the lateral decubitus position. Five patients are presented to illustrate the application of this technique in thoracic tumors with intimate spinal involvement.

RESULTS

The muscle-sparing, high thoracotomy approach afforded gross total resection and spinal reconstruction in five consecutive patients, including stage IV lung carcinoma with invasion of the T5 and T6 vertebral bodies, two malignant fibrous histiocytomas causing thoracic cord compression, a metastatic T6 lesion of unknown primary with associated cord compression; and a Pancoast tumor. All patients seen at 6 months had full symmetric shoulder range of motion postoperatively.

CONCLUSIONS

The described muscle-sparing, high thoracotomy approach provides excellent exposure of the ventral cervicothoracic and upper thoracic spine without the morbidity associated with the transection of shoulder girdle muscle bellies. This technique is particularly useful in patients with primary malignant bone tumors requiring en bloc excision and metastatic tumors with large soft tissue components.

A Prospective Study of Chronic Pain after Thoracic Surgery

BACKGROUND

The goal of this study was to detect the predictors of chronic pain at 6 months after thoracic surgery from a comprehensive evaluation of demographic, psychosocial, and surgical factors.

METHODS

Thoracic surgery patients were enrolled 1 week before surgery and followed up 6 months postsurgery in this prospective, observational study. Comprehensive psychosocial measurements were assessed before surgery. The presence and severity of pain were assessed at 3 and 6 months after surgery. One hundred seven patients were assessed during the first 3 days after surgery, and 99 (30 thoracotomy and 69 video-assisted thoracoscopic surgery, thoracoscopy) patients completed the 6-month follow-up. Patients with versus without chronic pain related to thoracic surgery at 6 months were compared.

RESULTS

Both incidence (P = 0.37) and severity (P = 0.97) of surgery-related chronic pain at 6 months were similar after thoracotomy (33%; 95% CI, 17 to 53%; 3.3 ± 2.1) and thoracoscopy (25%; 95% CI, 15 to 36%; 3.3 ± 1.7). Both frequentist and Bayesian multivariate models revealed that the severity of acute pain (numerical rating scale, 0 to 10) is the measure associated with chronic pain related to thoracic surgery. Psychosocial factors and quantitative sensory testing were not predictive.

CONCLUSIONS

There was no difference in the incidence and severity of chronic pain at 6 months in patients undergoing thoracotomy versus thoracoscopy. Unlike other postsurgical pain conditions, none of the preoperative psychosocial measurements were associated with chronic pain after thoracic surgery.

Combination of intracostal sutures with muscle flap to decrease post thoracotomy pain: A single blinded randomized clinical trial

OBJECTIVE

To assess the efficacy of intercostal nerve protection by intercostal muscle (ICM) flap in post-thoracotomy pain improvement compared to intracostal suturing.

METHODS

In a randomized controlled trial, ninety-four patients undergoing posterolateral thoracotomy surgery were divided into two subgroups. Intracostal sutures in isolation and in combination with ICM flap techniques were used for thoracotomy closure in both groups. Numeric Pain Scale and Visual Pain Scale as pain scores were assessed on the first, second, third, fourth, fifth, sixth and seventh postoperative days and follow-up visits during the 2^nd week, 1^st, 2^nd, 4^th and 6^th months after thoracotomy.

RESULTS

Out of 94 patients, 58 were male and 36 were females. While the mean age of patients in intracostal group was 45.3 ± 17.6 years, it was 47.4 ± 16.1 years in intracostal plus ICM flap group. The mean operation time for the first group was 191.0 ± 74.7 minutes, while it was 219.3 ± 68.8 minutes in the second (p>0.05). Numeric rating score and visual pain scale did not demonstrate any significant difference in pain severity on postoperative days and follow-up visits between both groups (p>0.05). Although the trend of pain reduction was significant in each group (p<0.001), the difference was not statistically significant (p>0.001).

CONCLUSION

Intracostal sutures in combination with muscle flap did not reduce postoperative pain in thoracotomy compared with intracostal sutures alone in thoracotomy closure.

Prevention of chronic post-surgical pain: the importance of early identification of risk factors

Chronic post-surgical pain (CPSP) is currently an inevitable surgical complication. Despite the advances in surgical techniques and the development of new modalities for pain management, CPSP can affect 15-60% of all surgical patients. The development of chronic pain represents a burden to both the patient and to the community. In order to have a meaningful impact on this debilitating condition it is essential to identify those at risk. Early identification of patients at risk will help to reduce the percentage of patients who go on to develop CPSP. Unfortunately, evidence about any effective actions to reduce this condition is limited. This review will focus on providing context to the challenging problem of CPSP. The possible role of both the surgeon and anesthesiologist in reducing the incidence of this problem will be explored.

Post-thoracotomy pain syndrome and sensory disturbances following thoracotomy at 6- and 12-month follow-ups

Background

Persistent pain affects a large proportion of patients after thoracotomy and is associated with sensory disturbances. The objective of this prospective study was to investigate the time course of pain and sensory disturbances over a 12-month period.

Methods

Patients scheduled for thoracotomy were recruited. Data were collected on the day before surgery, including baseline characteristics and the presence of any preoperative pain. At 6- and 12-month follow-ups, data on pain were collected using the Brief Pain Inventory-Short Form, and perceived sensory disturbances around the thoracotomy scar were recorded from a self-exploration test.

Results

At 12 months after surgery, 97 patients had complete data including baseline and 6-and 12-month measurements. Almost half of the patients reported post-thoracotomy pain at the follow-ups. However, 20% of the patients not reporting post-thoracotomy pain at 6 months did report it at 12 months. Between 40% and 60% of patients experienced some kind of sensory disturbance at 6 months. A small decline in some kind of sensory disturbance was reported by 20%–50% of patients at 12 months.

Conclusion

A proportion of patients experienced either resolved or delayed onset of pain. Sensory changes were strongly associated with post-thoracotomy pain syndrome, but were also present in a large proportion of patients without it.

Left Subclavian Artery Aneurysm: Surgical Repair Via a Sternal Incision

For trauma, the traditional approach to the proximal left subclavian artery is through a posterolateral thoracotomy. The purpose of this study was to evaluate the feasibility of accessing the proximal left subclavian artery through a partial sternotomy approach. Anatomical review of 52 subclavian arteries was performed on 52 randomly picked computed tomography (CT) scans of the thorax. The depth of the origin of the subclavian artery was measured from the lateral thoracic wall and from the sternum. It was noted that the distance from the sternum to the origin of the left subclavian artery was 4.71 cm as compared to the posterolateral wall, which was 8.87 cm. This is in contrast to the belief that the left subclavian artery is a posterior structure in the mediastinum. A subclavian artery aneurysm was repaired through the sternal approach and was noted to have an adequate exposure required for the procedure. This approach was necessitated owing to the fact that the patient had significant chronic obstructive pulmonary disease. From these data, the authors conclude that in elective circumstances it is easier and appropriate to use the partial sternotomy approach to access the proximal left subclavian artery, especially in patients who have reduced pulmonary function.

Subcostal closure technique for prevention of postthoracotomy pain syndrome

BACKGROUND

The purpose of this study was to evaluate the efficacy of our subcostal closure technique in prevention of postthoracotomy pain syndrome.

METHODS

From July 2012 to March 2015, 29 patients in whom a lobectomy was indicated underwent a thoracotomy. The thoracotomy wounds were closed using a subcostal closure technique (subcostal closure group) and outcomes were compared with 31 patients who underwent video-assisted thoracoscopic surgery (thoracoscopy group). The duration of oral opioid consumption was evaluated from medical records, and postoperative pain was evaluated by telephone interview conducted by a trained nurse practitioner who was unaware of the patient's group.

RESULTS

Pain scores were higher in the thoracoscopy group compared to the subcostal closure group, reaching statistical significance (Numeric Rating Scale 0.55 ± 0.948 in the subcostal closure group vs. 1.84 ± 1.614 in the thoracoscopy group; p < 0.001, Clinical Pain Scale 0.24 ± 0.435 in the subcostal closure group vs. 0.81 ± 0.703 in the thoracoscopy group; p < 0.001). The number of patients who consumed oral opioids for longer than 2 months after the operation was significantly greater in the thoracoscopy group than the subcostal closure group (6.9% in the subcostal closure group vs. 32.3% in the thoracoscopy group; p = 0.022).

CONCLUSIONS

The subcostal closure technique is useful to prevent postthoracotomy pain syndrome.

Persistent post-surgical pain and signs of nerve injury: the Tromsø Study

BACKGROUND

The contribution of nerve lesions and neuropathic pain to persistent post-surgical pain (PPSP) is poorly established. The aim of this study was to assess the association between PPSP and symptoms and signs of possible nerve injury in an unselected surgical sample.

METHODS

Eighty-one individuals with and without persistent pain after surgical procedures, were recruited from a cross-sectional study. Follow-up examination with questionnaires and quantitative sensory testing was performed 15-32 months later (21-64 months after surgery).

RESULTS

The median rating of maximum pain intensity among individuals with PPSP decreased from numerical rating scale 4/10 at baseline to 2/10 at follow-up, but considerable changes occurred in both directions. Individuals with PPSP at follow-up were significantly more likely to self-report sensory abnormalities than those without PPSP; however, results from sensory testing did not differ significantly between the groups. Self-report of sensory disturbances at the site of surgery was associated with increased warm detection thresholds and tactile pain thresholds. Among individuals with PPSP, 61% had positive findings on sensory testing, suggesting probable neuropathic pain.

CONCLUSION

In this study, associations between self-reported symptoms and PPSP were stronger than associations between self-reported symptoms and results of psychophysical tests. Fluctuations in pain intensity together with wide ranges for normal variability in sensory functions, hampers detection of significant group differences. Methodological aspects of quantitative sensory testing applied in a mixed clinical sample are discussed.

Paravertebral block versus thoracic epidural for patients undergoing thoracotomy

BACKGROUND

Operations on structures in the chest (usually the lungs) involve cutting between the ribs (thoracotomy). Severe post-thoracotomy pain can result from pleural (lung lining) and muscular damage, costovertebral joint (ribcage) disruption and intercostal nerve (nerves that run along the ribs) damage during surgery. Poor pain relief after surgery can impede recovery and increase the risks of developing complications such as lung collapse, chest infections and blood clots due to ineffective breathing and clearing of secretions. Effective management of acute pain following thoracotomy may prevent these complications and reduce the likelihood of developing chronic pain. A multi-modal approach to analgesia is widely employed by thoracic anaesthetists using a combination of regional anaesthetic blockade and systemic analgesia, with both non-opioid and opioid medications and local anaesthesia blockade.There is some evidence that blocking the nerves as they emerge from the spinal column (paravertebral block, PVB) may be associated with a lower risk of major complications in thoracic surgery but the majority of thoracic anaesthetists still prefer to use a thoracic epidural blockade (TEB) as analgesia for their patients undergoing thoracotomy. In order to bring about a change in practice, anaesthetists need a review that evaluates the risk of all major complications associated with thoracic epidural and paravertebral block in thoracotomy.

OBJECTIVES

To compare the two regional techniques of TEB and PVB in adults undergoing elective thoracotomy with respect to:1. analgesic efficacy;2. the incidence of major complications (including mortality);3. the incidence of minor complications;4. length of hospital stay;5. cost effectiveness.

SEARCH METHODS

We searched for studies in the Cochrane Central Register of Controlled Trials (CENTRAL 2013, Issue 9); MEDLINE via Ovid (1966 to 16 October 2013); EMBASE via Ovid (1980 to 16 October 2013); CINAHL via EBSCO host (1982 to 16 October 2013); and reference lists of retrieved studies. We handsearched the Journal of Cardiothoracic Surgery and Journal of Cardiothoracic and Vascular Anesthesia (16 October 2013). We reran the search on 31st January 2015. We found one additional study which is awaiting classification and will be addressed when we update the review.

SELECTION CRITERIA

We included all randomized controlled trials (RCTs) comparing PVB with TEB in thoracotomy, including upper gastrointestinal surgery.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Two review authors (JY and SG) independently assessed the studies for inclusion and then extracted data as eligible for inclusion in qualitative and quantitative synthesis (meta-analysis).

MAIN RESULTS

We included 14 studies with a total of 698 participants undergoing thoracotomy. There are two studies awaiting classification. The studies demonstrated high heterogeneity in insertion and use of both regional techniques, reflecting real-world differences in the anaesthesia techniques. Overall, the included studies have a moderate to high potential for bias, lacking details of randomization, group allocation concealment or arrangements to blind participants or outcome assessors. There was low to very low-quality evidence that showed no significant difference in 30-day mortality (2 studies, 125 participants. risk ratio (RR) 1.28, 95% confidence interval (CI) 0.39 to 4.23, P value = 0.68) and major complications (cardiovascular: 2 studies, 114 participants. Hypotension RR 0.30, 95% CI 0.01 to 6.62, P value = 0.45; arrhythmias RR 0.36, 95% CI 0.04 to 3.29, P value = 0.36, myocardial infarction RR 3.19, 95% CI 0.13, 76.42, P value = 0.47); respiratory: 5 studies, 280 participants. RR 0.62, 95% CI 0.26 to 1.52, P value = 0.30). There was moderate-quality evidence that showed comparable analgesic efficacy across all time points both at rest and after coughing or physiotherapy (14 studies, 698 participants). There was moderate-quality evidence that showed PVB had a better minor complication profile than TEB including hypotension (8 studies, 445 participants. RR 0.16, 95% CI 0.07 to 0.38, P value < 0.0001), nausea and vomiting (6 studies, 345 participants. RR 0.48, 95% CI 0.30 to 0.75, P value = 0.001), pruritis (5 studies, 249 participants. RR 0.29, 95% CI 0.14 to 0.59, P value = 0.0005) and urinary retention (5 studies, 258 participants. RR 0.22, 95% CI 0.11 to 0.46, P value < 0.0001). There was insufficient data in chronic pain (six or 12 months). There was no difference found in and length of hospital stay (3 studies, 124 participants). We found no studies that reported costs.

AUTHORS' CONCLUSIONS

Paravertebral blockade reduced the risks of developing minor complications compared to thoracic epidural blockade. Paravertebral blockade was as effective as thoracic epidural blockade in controlling acute pain. There was a lack of evidence in other outcomes. There was no difference in 30-day mortality, major complications, or length of hospital stay. There was insufficient data on chronic pain and costs. Results from this review should be interpreted with caution due to the heterogeneity of the included studies and the lack of reliable evidence. Future studies in this area need well-conducted, adequately-powered RCTs that focus not only on acute pain but also on major complications, chronic pain, length of stay and costs.

The Acute to Chronic Pain Transition: Can Chronic Pain Be Prevented?

Chronic postsurgical pain (CPSP) is a distressing disease process that can lead to long-term disability, reduced quality of life, and increased health care spending. Although the exact mechanism of development of CPSP is unknown, nerve injury and inflammation may lead to peripheral and central sensitization. Given the complexity of the disease process, no novel treatment has been identified. The preoperative use of multimodal analgesia has been shown to decrease acute postoperative pain, but it has no proven efficacy in preventing development of CPSP.

Postthoracotomy Pain Syndrome Following Surgery for Lung Cancer: Symptoms and Impact on Quality of Life

Postthoracotomy pain syndrome (PTPS) is a common complication following thoracic surgery. Most studies examining the influence of PTPS on patient-reported symptoms include few patients managed using a minimally invasive approach. Associated sensory changes, potentially neuropathic in origin, are not well described. We therefore examined the symptoms and quality of life (QOL) of patients with and without PTPS who underwent a standard thoracotomy (n = 43) or minimally invasive surgery (n = 54). Patients in this prospective, cross-sectional study completed questionnaires to assess pain (McGill Pain Questionnaire), neuropathic symptoms (Neuropathic Symptom Questionnaire), symptom distress (Symptom Distress Scale), anxiety and depression (Hospital Anxiety and Depression Scale), and QOL (Functional Assessment Cancer Therapy–Lung). Excepting younger age (p = .009), no demographic or surgical characteristic differentiated patients with and without PTPS. Patients with PTPS described discomfort as pain only (15.1%), neuropathic symptoms only (30.2%) or pain and neuropathic symptoms (54.7%). Scores differed between patients with and without PTPS for symptom distress (p < .001), anxiety and depression (p < .001), and QOL (p = .009), with higher distress associated with PTPS. Despite new surgical techniques, PTPS remains common and results in considerable distress. A focused assessment is needed to identify all experiencing this condition, with referral to pain management specialists if symptoms persist.

A review of the literature on multiple factors involved in postoperative pain course and duration

OBJECTIVE

To review the literature on the progression from acute to chronic postoperative pain, to evaluate the evidence for the risk of progressing to persistent postoperative and chronic pain, and to identify characteristics of pharmacologic treatments to best tailor therapy to an individual patient's pain profile.

BACKGROUND

Pain is most commonly classified by duration (acute, chronic) and pathophysiology (nociceptive, neuropathic); however, these descriptors alone incompletely describe pain. Additionally, the transition between acute and chronic postoperative pain is not well understood.

METHODS

We conducted a qualitative review and evaluation of the literature on postoperative pain with respect to the above objectives.

RESULTS

Individualized pharmacologic treatments require a complete characterization of a patient's pain profile, in terms of frequency of pain over the course of a 24-hour day and over time thereafter, frequency and duration of pain flares, and presence of neuropathic pain. These considerations can help guide the choice of pharmacologic treatment to meet patient needs over a 24-hour day and over time after surgery. With respect to opioid analgesics, acute pain requires rapid onset of analgesia and the ability to titrate analgesia to the changing characteristics of pain over a short period. For these reasons, short-acting opioid analgesics have been preferred; however, there are opioid formulations with rapid onset and extended release for reduced dosing frequency. Although nociceptive pain can typically be controlled by titration of the dose of an opioid analgesic, neuropathic pain may respond better to the addition of an antineuropathic medication rather than to opioid dose escalation.

CONCLUSION

Advances in individualized pharmacologic treatment for postoperative pain have resulted in better pain control. Moreover, the recognition of sub-acute pain as a new entity is important because many surgical patients will need therapy beyond the first 8 days after surgery. In this group of patients the diagnosis of a neuropathic pain component will be important so that appropriate multimodal therapy may be implemented.