2020, Number 1
Radiofrequency ablation of intercostal nerves for pain management in multiple rib fractures
Full text
10.35366/92708
Language: English/Spanish [Versi?n en espa?ol]
References: 19
Page: 24-30
PDF size: 248.82 Kb.
ABSTRACT
Introduction: Trauma continues to be a major problem that is confronted daily by doctors, surgeons and the emergency systems in general, particularly in blunt thoracic trauma. The pain that the patients have usually is severe restricting in an important way the ventilation and furthermore it generally produces lung atelectasis and neumony because the patients can't move lung secretions. The main objective of this article is to show that the use of intercostals nerve ablation diminishes the pain of the patient with blunt thoracic trauma by the review of the first 12 cases of blunt thoracic trauma with multiples rib fractures treated with radiofrequency ablation of the intercostal nerves guided by fluoroscopy or ultrasound and electric impedance in order to diminish the pain before or after surgery. Material and methods: It was a retrospective study of 12 patients with blunt thoracic trauma who had difficulties with the ventilation because of the intensity of the pain. The cause of the trauma were car and motorcycle accidents, falls form different heights (10-25 m). The patients had general anesthesia and intubation before the procedure followed by ablation of the intercostal nerves proximal to the rib fracture guided by fluorosocopy or ultrasound and impedance. The correct placement of the needle was done by electric impedance and motor and sensory stimulations. The nerve ablation of the intercostals nerves of the rib fractures were done with 60 oC for one minute for each nerve using the NeuroTherm NT 1100 (registered marc). Variables: qualitative variables used for description of the population was accomplished by age, gender, mechanism of the trauma. Pain intensity was measured by the quantitative pain number scale before and after the treatment and with exhalation, before and after treatment, quantitative variables studied: number of rib fractured, injured severity scale score, and revised trauma score, morphine use in mg before and after the treatment description of the result by average and standard deviation. Results: Pain intensity was diminished in 70%, and the daily morphine consumption was also diminished in 70.8%. Alodine as a complication of the treatment was found in a 41.2% of the cases and was easily controlled with gabapentinoids for two weeks. Conclusion: The use of intercostal nerve ablation with radiofrequency in thoracic blunt trauma is effective and safe. It controls the pain significantly and improves the ventilation of the patient diminishing the morphine consumption. This technique could become the new gold standard in the treatment of pain in the severe thoracic blunt trauma.INTRODUCTION
Worldwide, trauma is a public health problem and a leading cause of mortality in all age groups. Quite often, trauma pain requires opioids and is not uncommonly undertreated.
Blunt chest trauma is a frequent problem, whether due to unrestrained motor vehicle accidents, motorcycles, bicycle falls, or falls from own height and being run over. In these cases, multiple rib fractures occur frequently and may be accompanied by hemopneumothorax or even unstable thorax. Regardless of the risk that these pathologies may represent for the patient's life, once they are resolved in the initial evaluation according to the Advanced Trauma Life Support (ATLS) protocol of the American College of Surgeons, the pain persists. This pain is usually very severe, ranging from 9 to 10 on the numerical pain scale, intensifies on deep inspiration and significantly limits the patient's ventilatory mechanics, delaying extubating time in intensive care units due to pain on inspiration and poor secretion management because of the inability to expectorate.
This pain usually requires high doses of opiates with the side effects that this implies such as nausea, vomiting, headache, respiratory depression, sedation of the patient and delirium, and can also mask other injuries such as cranioencephalic trauma, abdominal blunt trauma, and compartment syndrome, which is not uncommon for the three entities to coincide in this trauma kinematics.
Since 1945 thoracic nerve blocks have been used to reduce pain from thoracic trauma. During World War II it was a valuable resource for reducing pain from fractured ribs.1,2
However, although infiltration of anesthetics to the affected intercostal nerves produced significant pain relief and analgesic reduction, its effect was short-lived.3,4
The installation of a peridural catheter with continuous infusion of opioids improved analgesia in these patients. However, it presented the problem of mobilizing a polytraumatized patient to perform it, in addition to the hypotension associated with the continuous infusion due to vasodilatation associated in hemodynamically unstable patients or with cranioencephalic trauma, aggravating the state of shock and decreasing cerebral perfusion.5,6
Radiofrequency acts by producing thermal ablation of the involved intercostal nerve by means of a needle placed in the subcostal canal guided either by ultrasound or fluoroscopy.7-10
This permanent damage to the intercostal nerve provides significant analgesia, can be performed with the patient in dorsal decubitus position without the need for posture changes and may even be carried out in the intensive care unit if ultrasound is used as a guide. The analgesia provided is permanent, which allows the patient to have good respiratory mechanics, prevents pulmonary atelectasis or pneumonia, and reduces the use of analgesics.11-15
Based on the above, radiofrequency of the intercostal nerves was started in our hospital to treat pain and improve respiratory mechanics in patients with blunt chest trauma. This work arose from the need to be able to control the severe pain presented by these patients and to improve their respiratory mechanics for early extubating, and it has emerged as an option to traditional medical and surgical treatment of this kind of patients in our hospital. The aim of this article is to describe this case series treated by this method at the Hospital Angeles Lomas in Mexico City, Mexico.
MATERIAL AND METHODS
The physical and, where appropriate, electronic records of patients with blunt chest trauma treated with intercostal nerve radiofrequency at Hospital Angeles Lomas from January 2006 to August 2018 were retrospectively reviewed. During this period, 12 patients were treated with this technique, with prior informed consent of the patient and/or his/her family for the intercostal nerve thermal ablation technique, in addition to the corresponding informed consents signed for other types of surgical treatments that the patient merited due to blunt chest trauma and multiple rib fractures.
Patients were resuscitated according to the ATLS protocol. After their stabilization and having treated priority lesions of other organs (24 to 72 hours later), the patients were subjected, prior intubation, to radiofrequency ablation in the fluoroscopy room, or by ultrasonographic control in the same Intensive Care Unit.
NeuroTherm® thermo-ablation needles, model Simplicity III, were used. The intercostal nerve involved was located proximal to the fracture. The correct position of the needle was corroborated by impedance, motor and sensory stimulation and the intercostal nerves were ablated at 60 oC for one minute for each nerve using the NeuroTherm NT 1100 equipment (Figure 1).
Pain was assessed using a numerical pain scale, at rest with shallow breathing and with expiration pre-radiofrequency and post-radiofrequency. Pain intensity was also indirectly measured by daily opioid consumption. All patients were conscious when pain was assessed.
To measure pre- and post-radiofrequency opioid consumption, the amount of morphine in milligrams (mg) administered intravenously in 24 hours required by each patient was documented. In the cases in which morphine was not used, other analgesic drugs were converted to mg of morphine, seeking the equivalence of other opioids to morphine to be able to unify and compare the daily consumption of morphine pre-treatment and post-treatment.
RESULTS
During this period, 12 patients with blunt chest trauma and multiple rib fractures were treated with this ablation technique. Five female and seven male patients, ranging in age from 28 to 76 with an average of 57.5 years, with the following trauma kinematics, were included: six automobile accidents, two motorcycle accidents and four falls (2 from their own height, and one each from 10 and 25 m), with a range of fractured ribs from three to 10 and an average of six ribs. Trauma intensity was graded using the combined trauma score scale and the Trauma Injury Severity Index (TRISS) of the American Association for the Surgery of Trauma with a range of 1.1 to 49.7, a mean of 11.71 and a standard deviation of 13.12 points. Patients with blunt trauma were graded as severe (8.3%) using these scales from 1 to 12.
All 12 patients had a mean number of fractured ribs of 5.75 with a standard deviation of 2.18. Pain was measured at rest with shallow breathing and on exhalation (Figure 2).
Pain at rest with shallow breathing before radiofrequency had a mean of 7.6 points on the numerical scale with a standard deviation of 2.18 points. After intercostal nerve ablation the mean was 2.08 with a standard deviation of 1.73 on the numerical pain scale. Pain on exhalation was measured before radiofrequency with a mean of 9.75 and a standard deviation of 0.62 and after radiofrequency with a mean of 2.75 and a standard deviation of 1.36 using this same scale.
The dose in mg per day of morphine equivalent opioids administered intravenously before radiofrequency had a mean of 26.67 mg in 24 hours with a standard deviation of 10.5 mg and after radiofrequency was 7.79 mg in 24 hours with a standard deviation of 0.28 (Table 1).
Pain decreased by 70% post-radiofrequency at rest, and at expiration was also reduced by 70%, and opioid consumption in mg per 24 hours was reduced by 70.8%.
The complications observed with the radiofrequency technique were mild and consisted mainly of transient allodynia in 41.2% of the patients that was controlled with gabapentin-like drugs every eight hours for two weeks. There were no serious complications or mortality in this series. In some cases, fixation of the fractured ribs was combined with trans operative intercostal thermal ablation when the patient presented with an unstable thorax or rib displacement.
Complications attributed to this technique were minor, mainly due to mild and transient allodynia in 41.2% of the cases controlled with low dose gabapentin-like drugs for two weeks. There were no cases of post-ablation pneumothorax or mortality in this series.
DISCUSSION
Currently, pain is considered the fifth vital sign and pain relief is now seen as a fundamental right of the patient at the international level, and it has been decreed by the World Health Organization (WHO) as one of the human rights. Currently, it is a serious breach of professional ethics not to treat or undertreat the patient's pain.
Pain management in the trauma patient is a challenge. Initial assessment and treatment of life-threatening or limb-threatening injuries takes priority and initiation of analgesia is often postponed until the patient is stable. The first-line treatment for the trauma patient is low-dose opioids administered intravenously. They act rapidly, are effective and are indicated in severe pain. However, there are multiple reasons why the trauma patient receives insufficient analgesia: physicians are reluctant to administer opioids systemically due to fear of aggravating hemodynamic instability or respiratory depression with airway loss. In addition, in patients with head injury, there is concern about masking the clinical picture or producing delirium, particularly in elderly patients, which may confound the clinical picture of head injury. Frequent patient assessments are usually needed without sedation and it is not possible to estimate whether the patient is really deteriorating.16,17
Another reason why patients do not receive adequate analgesia is because it is difficult to measure pain in trauma because patients are often intubated and mechanically ventilated, and communication cannot be established.18
Based on the above, multimodal analgesia and in particular regional analgesia, such as radiofrequency ablation, significantly reduce opioid requirements, shortening the stay in the intensive care unit and emergency rooms, recovery, reducing the adverse effects of these drugs such as nausea, vomiting, headache, respiratory depression, delirium, vasodilatation with hypotension, constipation, pruritus, and immunosuppression all of which requires more staff for surveillance and monitoring.
In this case series it was evident how radiofrequency of the intercostal nerves significantly reduced morphine consumption in mg per 24 hours (70.8%) by producing high quality analgesia that is specific to the chest wall, and therefore, without systemic effects.
In our patients, pain managed with intercostal nerve ablation by radiofrequency decreased from severe pain (from 7-10 points) with a mean of 7.5 points with superficial ventilation measured with a numerical pain scale, to a pain of 2-4 with a mean of 2, being a mild pain and attributed to the fact that there are also other causes of pain in thoracic trauma independent of rib fractures. This represented an approximate relief of 70% in most cases since it was possible to manage pain without opiates and with other types of analgesics, which was of great help for the intensive care unit since the patients could be extubated earlier due to a much better respiratory mechanics, achieving a deeper inspiration and expiration and consequently, a better management of airway secretions with less possibilities of complications like pulmonary atelectasis and pneumonia.
The results observed in our study agree with the world literature in observing a significant reduction in daily morphine consumption.15,19
CONCLUSION
Trauma is a worldwide public health problem and one of the main causes of mortality in all age groups. The pain produced particularly by blunt trauma of the thorax is severe, usually requires opiates, and it is not uncommon to be undertreated for several reasons.
Thermal ablation of the intercostal nerves by radiofrequency in blunt chest trauma with multiple rib fractures and unstable thorax is a useful and safe procedure for the treatment of these patients. In this case series it was evident how radiofrequency of the intercostal nerves significantly decreased morphine consumption in mg per 24 hours (70.8%) by producing high quality analgesia specific to the chest wall and therefore without side effects.
This technique significantly reduces pain and allows better ventilation with less consumption of other analgesics.
Thermal ablation of the intercostal nerves may emerge as a new gold standard for pain control in severe chest trauma. Larger studies with higher number of patients are required to further validate these initial conclusions.
REFERENCES
AFFILIATIONS
1 Head, Pain Clinic. Hospital Ángeles Lomas, Mexico City, Mexico.
2 Trauma team surgeon. Hospital Ángeles Lomas, Mexico City, Mexico. Teaching and Research Center Coordinator. Hospital Ángeles Lomas, Mexico City, Mexico.
3 General Surgeon and Endoscopist of the Pain Clinic. Hospital Ángeles Lomas, Mexico City, Mexico.
Ethical considerations and responsibility: Data privacy. In accordance with the protocols established at the authors\' work site, the authors declare that they have followed the protocols on patient data privacy while preserving their anonymity. The informed consent of the patient referred to in the article is in the possession of the author.
Funding: No financial support was received for this study.
Disclosure: The authors declare that they do not have any conflict of interests in the conduction of this work.
CORRESPONDENCE
Dr. Rafael Acuña-Prats. E-mail: acunaprats@gmail.comReceived: 02/21/2019. Accepted: 02/05/2020