Opioid Free Anaesthesia-Analgesia Strategy on Surgical Stress and Immunomodulation in Elective VATS-Lobectomy for NSCLC

Effect of a Perioperative Opioid Free Anaesthesia-Analgesia (OFA-A) Strategy on Surgical Stress Response and Immunomodulation in Elective VATS Lobectomy for NSCLC Lung Cancer: A Prospective Randomized Study

Lobectomy is a major, high-risk surgical procedure that in addition to one-lung ventilation (OLV) exerts a potent surgical stress response. An overwhelming immune cell recruitment may lead to excessive tissue damage, peripheral organ injury and immunoparesis. The effect of anesthesia on the immune system is modest, compared to the effects induced by major surgery. However, to an immunocompromised patient, due to cancer and/or other comorbidities, the immunosuppressive effects of anesthesia may increase the incidence of post-operative infections, morbidity, and mortality. Exogenous opioids have been correlated with immunosuppression, opioid-induced hyperalgesia, and respiratory depression, with deleterious outcomes. An Opioid-Free Anaesthesia-Analgesia (OFA-A) strategy is based on the administration of a variety of anaesthetic/analgesic and other pharmacological agents with different mechanisms of action, including immunomodulating and anti-inflammatory effects. Our basic hypothesis is that the implementation of a perioperative multimodal OFA-A strategy, will lead to an attenuated surgical stress response and attenuated immunosuppression, compared to a conventional Opioid-Based Anaesthesia-Analgesia (OBA-A) strategy. The aforementioned effects, are presumed to be associated with equal or improved analgesia and decreased incidence of postoperative infections compared to a perioperative OBA-A technique.

Surgical manipulation and one lung ventilation (OLV) exert different and synergic effects to generate an inflammatory response during lung resection surgery. Surgery, such as lobectomies, often leads to severe immunosuppression that in turn can lead to infectious complications and sepsis. Both anesthesia-related and surgery-related perioperative measures may modulate the patient's immune response and lead to the activation of different components of the immune system. Anesthesia-induced activation, in particular of the adaptive immune system, may also induce persistent, postoperative immunosuppression. An overwhelming immune cell recruitment may lead to excessive tissue damage, peripheral organ injury and immunoparesis.

Opioid analgesia remains the corner stone of acute pain management in perioperative analgesic regimes. Opioid receptors are not only expressed in the central nervous system to regulate pain perception but also occur on immune and tumour cells. Exogenous opioid administration has been correlated with immunosuppression, opioid-induced hyperalgesia, and respiratory depression, with deleterious outcomes.

An Opioid-Free Anaesthesia-Analgesia (OFA-A) strategy is based on the administration of a variety of anaesthetic/analgesic and other pharmacological agents with different mechanisms of action, including immunomodulating and anti-inflammatory effects where at least one factor causes inhibition of central sensitization and at least another factor inhibits the peripheral sensitization of the nervous system, as a response to painful surgical stimuli. This combination of factors has to have a synergistic or additive effect so that best analgesic effects can be achieved with the lowest possible dosage.

Our basic hypothesis is that a perioperative OFA-A strategy on cancer patients undergoing VATS lung surgery for tumour resection will be accompanied by abolished or attenuated immunosuppression. The additional potential clinical implication of a perioperative OFA-A strategy is the avoidance of the onco-proliferative side effects of both exogenous and endogenous opioids, released by cytokine-mediated immune cell activation. Inflammatory response inhibition is expected to reduce the possibility of acute and chronic post-operative pain developement, compared to a perioperative Opioid-Based Anaesthesia- Analgesia (OBA-A) technique. Additionally, the aforementioned inflammatory response inhibition is expected to lead to an overall reduction of overall postoperative pulmonary complications.

Inclusion Criteria:

• patients undergoing elective VATS lobectomy
• early stage NSCLC (up to T3N1M0)

Exclusion Criteria:

• Immunocompromised patients
• previous lung surgery
• preoperative corticosteroid or immunosuppressive drug use
• uncontrolled Diabetes Mellitus
• cardiac failure (NYHA 3 and 4)
• preoperative infection (CRP >5mg/ml, WBC >10x10^9/L)
• preoperative anemia (Hb<12g/dl)
• chronic inflammatory diseases
• inflammatory bowel disease

Group-specific exclusion criteria:

• OFA-Α: perioperative opioid administration, within the study period
• OBA-Α: perioperative dexmedetomidine or lidocaine infusion, ketamine, gabapentinoid or corticosteroid administration within the study period