Our case report was able
to demonstrate decreased pain levels after the adoption of the
ultrasound-guided TTMP block. In the postoperative period of cardiovascular
surgeries, the control of chest pain may become a major challenge. High doses
of opioids are not always effective for good analgesic control and, in
addition, the incidence of opioid addiction increases as larger amounts are
administered postoperatively [4], which significantly increases costs and
morbidity [1].
The chronic use of
opioids has become a major concern, in the USA opioid dependence has already
been declared a public health emergency. In 2017 there were 47,600 deaths
related to its use, which already represents more deaths each year than
collisions. Motor vehicles or breast cancer [4]. The prescription of opioids on
discharge from the postoperative period of cardiac surgery increases the risk
of chemical dependence, with approximately 1 in 10 patients undergoing cardiac
surgery can develop its chronic use [4]. The TTMP block thus becomes an
important adjuvant therapy not only for analgesic control, but also for
reducing the need for opioids, especially after hospital discharge, and might
be an option in cases like the one here described.
The persistence of pain
in the thoracic region due to ineffective analgesia can limit pulmonary
expansion, making it difficult to perform physiotherapy and cardiopulmonary
rehabilitation in addition to increasing the likelihood of chronic pain. Poorly
controlled acute surgical pain can be highly debilitating and has been
associated with chronic pain seen in about 20% of patients after sternotomy [5].
Restricted postoperative ventilation can result in atelectasis,
hypoventilation, pneumonia, and increased hospital stay [2]. To combat such
complications, the performance of postoperative physiotherapy is essential and
proves to be effective in restoring ventilatory capacity and minimizing
complications, as previously demonstrated by our group [6]. In the case
presented here, the analgesia induced by the TTMP block enabled all sessions to
be carried out without complications.
Historically, TTMP block
was initially used in the resection of breast cancer with contraindication to
general anesthesia. It can be done by injecting 15 mL of levobupivacaine
(0.15%) between the transverse thoracic muscle and the internal intercostal
muscle between the third and fourth left ribs in connection with the sternum. A
landmark to identify the TTMP is the short-axis view of the internal thoracic
artery and vein, which superficially locates the transverse chest muscle. When
the tip of the needle is considered to achieve TTMP on the ultrasound image, a
small amount (less than 2 mL) of the local anesthetic test dose is injected
after confirmation of negative aspiration. If the local anesthetic spreads are
seen above the costal cartilage in the sagittal parasternal view, then the
local anesthetic was injected superficially into the internal intercostal
muscle. The local spread of the anesthetic deep in the costal cartilages
indicates an appropriate block [7].
It is important to
highlight that the TTMP blocks are not free of drawbacks. Potential
complications are rare and include bleeding, infection, pneumothorax and local
anesthetic intoxication [8]. Because this technique is performed with
ultrasound guidance, it greatly reduces the risk of both pneumothorax and
bleeding and poisoning by local anesthetic, it also has the advantage of not
entering the neuroaxis and thus not presenting contraindications in relation to
the use of anticoagulation [9].
Thus, TTMP blocks may
become an optional analgesia modality in cardiovascular surgeries, considering
that it not only provides better analgesic control, sparing opioids, reducing
chronic pain and length of hospital stay, but also has an exceptionally low
rate of possible complications. In order to obtain better pain control in the
postoperative period of cardiac surgeries, involving other professionals in the
discussion about therapeutic options, as in the case in question, where the
anesthesiology team was called, was essential for the presentation of a new
path that made it possible to decrease the patient's pain, since the
conventional analgesic measures proposed by the attending physician in the
intensive care unit were not effective.
The major limitation of
this article is the fact that it is only a case report involving a single
patient. For TTMP blocks to be considered a therapeutic option at massive
levels, randomized clinical trials are necessary and shall be performed in the
future.
In the present case, the
TTMP block was effective in reducing pain in the postoperative period of
cardiac surgery and may be a tool in the anesthesiology arsenal.