Thoracic Blocks Versus Thoracic Epidural and Patient Controlled Anesthesia in Traumatic Rib Fracture Patients
Condition: Traumatic Rib Fracture
MeSH terms: Fractures, Bone; Rib Fractures
Study type: Interventional

Summary: 
      The primary objective of this study is to investigate whether continuous PVB is equal in
      efficacy to epidural anesthesia in terms of analgesia in patients with INR lower than 1.2, or
      is continuous ICNB equal in efficacy to PCA in terms of analgesia, if patients have INRs
      equal to or greater than 1.2.
    

Detailed description: 
      Rib fractures are the most common injury sustained following blunt trauma. Ziegler and
      Agarwal noted that in a population of more than 7000 trauma patients, 10% had fractured ribs.
      These injuries are normally the hallmark of significant chest trauma; and as the number of
      fractured ribs increases, there is an exponential increase in morbidity and mortality.

      This injury therefore poses a challenging problem from both pulmonary and analgesia
      standpoints. Significant morbidity is often the result of hypoventilation leading to
      atelectasis, pneumonia, and respiratory failure. Pain management has been recognized as an
      important factor in preventing these complications.

      Good analgesia may help to improve a patient's respiratory mechanics, leading to a decreased
      need for mechanical ventilatory support, a shortened hospital stay, and can dramatically
      alter the course of recovery impacting both morbidity and mortality.

      For healthy patients with one to two fractured ribs, systemic analgesics may suffice. For
      more than three to four fractured ribs, studies and experience have reaffirmed the superior
      analgesia made possible with continuous thoracic epidural, continuous thoracic paravertebral,
      and continuous intercostal block, however, a comparative head to head trial comparing the
      relative merits and disadvantages of each technique has not been undertaken in multiple rib
      fracture patients. Placing a catheter, which is possible with the use of all three
      techniques, allows the continuation of analgesia for multiple days with just one block, which
      is an essential option when treating patients that are likely to need extended analgesia.

      All options are not available for all patients, however, as the current American Society of
      Regional Anesthesiology advises against the performance of epidural or paravertebral blocks
      in patients with abnormal INR (at the BWH, equal or above 1.2, and/or treatment with other
      anticoagulants such gpIIb/IIIa inhibitors (heparin and heparin-like medications are usually
      acceptable within certain dosing time frames).

      Rib fractures following trauma are associated with severe postoperative pain and significant
      morbidity. Atelectasis, pneumonia, pulmonary embolism (PE), and intensive care admission are
      related to poor analgesia and consequent immobility and splinting during inspiration. With
      traumatic multiple fractured ribs (MFR), concomitant lung injury is expected. The effect of
      this injury is exacerbated when the pain of MFR leads to guarding, shallow breaths, and
      suboptimal chest physiotherapy. Atelectasis, pneumonia, consolidation, and respiratory
      failure ensue, necessitating or prolonging assisted ventilation and/or oxygenation and
      increasing morbidity and mortality. Additionally, inadequately treated pain after rib
      fractures can lead to chronic pain and global deconditioning.

      Without the implementation of effective regional and/or neuraxial analgesia, the need for the
      use of sedative and systemic opioid medications increases, which has the potential to
      increase the length of stay and increase complications such as delirium, aspiration,
      decreased mobility with subsequent greater deconditioning and increased risk for embolic
      events, addiction, and possibly chronic pain. These risks are even higher in older
      individuals (age > 55), in whom comorbidities and poor respiratory reserves conspire to
      increase morbidity and mortality, and who are less able to handle and recover from the side
      effects of sedative and systemic opioid medications. Additionally, trauma patients may also
      be at higher risk due to multiple, and often confounding, injuries.

      Options for analgesia aside from regional blocks include the use of NSAIDs, acetaminophen,
      opioids, ketamine, and transdermal lidocaine (patch). The short-term disadvantages of NSAID
      include gastric irritation, platelet inhibition and renal injury. Acetaminophen at high doses
      is hepatotoxic. Powerful opioids are depressants, suppress cough, increase risk of delirium,
      and may promote respiratory complications even as they reduce pain. Ketamine causes
      dissociation and risk of hallucinations, often of an unpleasant nature. Assessment of head
      and abdominal injuries can be compromised by systemic opioids or ketamine. Of note, none of
      these medications at well tolerated doses are sufficient to greatly diminish the pain of MFR
      during chest physiotherapy and coughing, delaying recovery, and none of these treatments can,
      at well tolerated doses, provide sufficient analgesia without causing significant side
      effects, even in combination. Lidocaine patches over the fracture sites are ineffective.

      Regional/neuraxial blocks provide superior analgesia, the impact of a successful block is
      immediate and substantial, and, especially regarding elderly, some authorities have
      categorically stated that most 55-65 year-olds with three or four fractured ribs should
      receive a regional block. The relative lack of systemic sedation makes it easier to monitor
      patients with head and abdominal injuries, and the reduced need for systemic medications
      obviates their inherent concomitant risks.

      Though effective, the use of epidural blocks in the intubated and unresponsive patient,
      especially in the thoracic region, is currently not widely accepted for fear of inadvertent
      adverse neurologic complications. This said, the incidence of neurological complications
      associated with patients who cannot respond to incidental injury associated with the
      placement of epidural anesthesia under general anesthesia, as an example of an unresponsive
      patient, is not precisely known. Horlocker et al state the "possibility of serious
      complications may still be as high as 0.08%." Regardless of the exact incidence rate, the
      prevailing wisdom is that the risk benefit ratio does not support the practice of
      epidural/deep plexus regional anesthesia in unconscious patients because of the clear
      association of pain during placement or injection and subsequent injury, which speak to the
      need for feedback from the patient in preventing injury.

      In comparison to epidural analgesia, the major complication of PVB and ICNB is that of
      pneumothorax with no documented accounts of nerve damage due to the lateral anatomic plane of
      medication delivery in reference to the central nerve axis. However, in patients with a chest
      tube this risk is effectively obviated. Moreover, the use of ultrasound, which greatly
      enhances the ability to avoid of the pleura, further improves the accuracy and safety of
      these blocks.

      Additionally, in view of pain relief methods providing the greatest preservation of pulmonary
      spirometric function after thoracotomy-related rib trauma, the most effective analgesic
      method is paravertebral analgesia, with patients having approximately 75% of their
      preoperative values in the first 48 hours after surgery. Most other techniques e.g.
      traditional intercostal nerve blocks, epidural local anesthetics or local anesthetic-opiate
      combinations produce approximately a 55% preservation by 48 hours, with interpleural
      analgesia being the least effective, with a mean of 35% preservation by 48 hours, less even
      than TENS or cryoanalgesia. These findings suggest that a thoracic paravertebral block is the
      best available analgesic method in rib trauma patients: however, the above studies have been
      performed in the post-surgical setting and not the trauma setting, and concentrated their
      findings on respiratory parameters, and not pain relief, though the two may be related.

      The primary question the investigators wish to answer in this study is whether continuous PVB
      is equal in efficacy to epidural anesthesia in terms of analgesia in patients with INR lower
      than 1.2, or is continuous ICNB equal in efficacy to PCA in terms of analgesia, if patients
      have INRs equal to or greater than 1.2 as measured by difference in visual analog pain scores
      after 48 hours. Secondary questions are: do PVBs and ICNBs result in a favorable side effect
      profile, lower complication rate, improved pulmonary mechanics, decreased need for
      intubation, decreased length of intubation, reduced supplemental oxygenation needs, reduced
      length of stay, improved speed to work with physical therapy and/or occupational therapy,
      lesser need for short/long term rehabilitation at discharge, and lesser development of
      chronic pain when compared to epidural block and opioid PCA in rib fracture patients.
    

Intervention name(s): Paravertebral Block; Intercostal Nerve Block; Epidural Block
Intervention type(s): Procedure; Procedure; Procedure
Intervention description(s): The paravertebral block consists of injection of local anesthetics into the area next to the spinal column and results in regional pain control. This technique of this block may be performed on multiple levels if there are extensive rib fractures and may be performed on both sides of the rib cage depending on injury.; The intercostal nerve block will consist of placing a catheter which delivers pain medication into the area between the ribs. This technique of this block may be performed on multiple levels if there are extensive rib fractures and may be performed on both sides of the rib cage depending on injury.; The epidural block consists of continuous infusion of local anesthetics into the epidural catheter placed into the epidural space (next to the spinal column) and results in regional pain control. This technique of this block may be performed at the appropriate level so the pain of rib fracture may be better controlled.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Supportive Care
Keywords: Rib Fracture; Intercostal Nerve Block; Paravertebral Nerve Block