The influence of anaesthesia on cancer growth.

BACKGROUND: Oncological patients make up a large proportion of all surgical patients. Through its influence on the patient's inflammatory and immune system, the choice of anaesthetic technique has an indirect impact on the health of the individual patient and on public health. Both the specific and the non-specific immune system have a major influence on the recurrence of carcinomas. The pathophysiological basis for growth and metastasis after surgery is the physiological response to stress. Inflammation is the organism's universal response to stress. Anaesthetics and adjuvants influence perioperative inflammation in different ways and have an indirect effect on tumour growth and metastasis. In vitro studies have shown how individual anaesthetics influence the growth and spread of cancer, but clinical studies have not confirmed these results. Nevertheless, it is advisable to use an anaesthetic that has shown lesser effect on the growth of cancer cells in vitro. CONCLUSIONS: In this review, we focus on the area of the effects of anaesthesia on tumour growth. The field is still relatively unexplored, there are only few clinical prospective studies and their results are controversial. Based on the review of new research findings we report on recommendations about anaesthetics and anaesthetic techniques that might be preferable for oncological surgical procedures.

Crystalloids vs. colloids for fluid optimization in patients undergoing brain tumour surgery.

BACKGROUND: This randomised, double-blinded, single-centre study prospectively investigated the impact of goal directed therapy and fluid optimization with crystalloids or colloids on perioperative complications in patients undergoing brain tumour surgery. Main aim of the study was to investigate the impact of fluid type on postoperative complications. PATIENTS AND METHODS: 80 patients were allocated into two equal groups to be optimised with either crystalloids (n = 40) or colloids (n = 40). Invasive hemodynamic monitoring was used to adjust and maintain mean arterial pressure and cerebral oxygenation within the baseline values (± 20%) and stroke volume variation (SVV) ≤ 10%. Postoperative complications from different organ systems were monitored during the first 15 days after surgery. Hospital stay was also recorded. RESULTS: Crystalloid group received significantly more fluids (p = 0.003) and phenylephrine (p = 0.02) compared to colloid group. This did not have any significant impact on perioperative complications and hospital stay, since no differences between groups were observed. CONCLUSIONS: Either crystalloids or colloids could be used for fluid optimization in brain tumour surgery. If protocolised perioperative haemodynamic management is used, the type of fluid does not have significant impact on the outcome.

Remifentanil target-controlled infusion with intranasal dexmedetomidine for vitreoretinal procedures: a randomized controlled trial.

AIM: To evaluate the consumption of remifentanil (as a primary end-point), analgesia, sedation, hemodynamics, respiratory effects, and surgeon and patient satisfaction (as a secondary end-point) with dexmedetomidine sedation compared with those of remifentanil sedation in patients undergoing vitreoretinal surgery. METHODS: Patients subjected to retinal ophthalmic surgical procedures were randomized to one of two intraoperative sedation groups: one group (n=21) received intranasal dexmedetomidine plus intravenous remifentanil (DEX-REMI group), and the other group (n=19) received intravenous remifentanil only (REM group). The treatment was placebo-controlled. The sedation level was controlled according to the bispectral index, with target values between 80%-90%. Patient levels of comfort, sedation, and pain were documented. The number of intraoperative complications and the level of satisfaction were assessed. Remifentanil consumption and hemodynamic parameters were also included in the statistical analysis. RESULTS: The level of remifentanil consumption was significantly lower in the DEX-REMI group, but combination sedation improved the surgeon's, anesthesiologist's, and patients' satisfaction scores. Importantly, the number of complications was zero in the DEX-REMI group, while eight cases of complications were noted in the REM group. The DEX-REMI group showed lower mean minimal arterial pressure, but it was still in the normotensive range. CONCLUSIONS: For patients undergoing ophthalmic procedures, sedation with a combination of intranasal dexmedetomidine and an intravenous infusion of remifentanil provides lower remifentanil consumption, better satisfaction scores, and a lower complication rate than sedation with a remifentanil infusion alone.

Brainstem Anaesthesia after Retrobulbar Block.

Regional anaesthesia techniques in ophthalmology are usually utilized for day case surgery. During various procedures, profound akinesia of the eye and anaesthesia of the surgical site are required, both of which are achieved with retrobulbar block. Due to the anatomy of the eye, life-threatening complications are possible. An 82-year-old female with secondary post-herpetic uveitic glaucoma of the right eye presented at the Department of Ophthalmology for an elective trans-scleral laser cyclophotocoagulation. She was given a retrobulbar block to the right eye with 2 mL of 0.5% levobupivacaine and 2 mL of 2% lidocaine. The procedure was technically performed without any issues. 2-3 minutes after the injection she became lethargic and 5 minutes later she lost consciousness and developed severe hypotension with bradycardia and respiratory arrest. She was successfully intubated and resuscitated, using mechanical ventilation, vasoactive medications, fluid therapy and intravenous lipid emulsion. There are three mechanisms for local anaesthetic (LA) to reach the central nervous system after a retrobulbar block: systemic absorption of LA, direct intra-arterial injection and retrograde flow into the cerebral circulation, and injecting LA into the subdural space via puncturing the dural optic nerve sheath, the latter being most common. The clinical picture of our patient was very consistent with subdural anaesthesia after exposure of the pons, midbrain and cranial nerves to LA, i.e. brainstem anaesthesia. Following appropriate life support measures taken in our case, there was a successful outcome. To minimize the chance for brainstem anaesthesia after retrobulbar block, we recommend low volume with low concentration of LA and block performance by an experienced ophthalmologist or anaesthesiologist with proper technique. Patients receiving retrobulbar anaesthesia should be carefully monitored at least 20 minutes after the block. Life support equipment should be available before performing retrobulbar block.

Effect of propofol and sevoflurane on the inflammatory response of patients undergoing craniotomy.

BACKGROUND: The purpose of this randomised, single-centre study was to prospectively investigate the impact of anaesthetic techniques for craniotomy on the release of cytokines IL-6, IL-8, IL-10, and to determine whether intravenous anaesthesia compared to inhalational anaesthesia attenuates the inflammatory response. METHODS: The study enroled 40 patients undergoing craniotomy, allocated into two equal groups to receive either sevoflurane (n = 20) or propofol (n = 20) in conjunction with remifentanil and rocuronium. The lungs were ventilated mechanically to maintain normocapnia. Remifentanil infusion was adjusted according to the degree of surgical manipulation and increased when mean arterial pressure and the heart rate increased by more than 30 % from baseline. The depth of anaesthesia was adjusted to maintain a bispectral index (BIS) of 40-60. Invasive haemodynamic monitoring was used. Serum levels of IL-6, IL-8 and IL-10 were measured before surgery and anaesthesia, during tumour removal, at the end of surgery, and at 24 and 48 h after surgery. Postoperative complications (pain, vomiting, changes in blood pressure, infection and pulmonary, cardiovascular and neurological events) were monitored during the first 15 days after surgery. RESULTS: Compared with patients anaesthetised with sevoflurane, patients who received propofol had higher levels of IL-10 (p = 0.0001) and lower IL-6/IL-10 concentration ratio during and at the end of surgery (p = 0.0001). Both groups showed only a minor response of IL- 8 during and at the end of the surgery (p = 0.57). CONCLUSIONS: Patients who received propofol had higher levels of IL-10 during surgery. Neither sevoflurane nor propofol had any significant impact on the occurrence of postoperative complications. Our findings should incite future studies to prove a potential medically important anti-inflammatory role of propofol in neuroanaesthesia. CLINICAL TRIAL REGISTRATION: Identified as NCT02229201 at www.clinicaltrials.gov.

Antiinflammatory effect of sevoflurane in open lung surgery with one-lung ventilation.

AIM: To prospectively assess the antiinflammatory effect of volatile anesthetic sevoflurane in patients undergoing open lung surgery with one lung ventilation (OLV). METHODS: This prospective, randomized study included 40 patients undergoing thoracic surgery with OLV (NCT02188407). The patients were randomly allocated into two equal groups that received either propofol or sevoflurane. Four patients were excluded from the study because after surgery they received blood transfusion or non-steroid antiinflammatory drugs. Inflammatory mediators (interleukins 6, 8, and 10, C-reactive protein [CRP], and procalcitonin) were measured perioperatively. The infiltration of the nonoperated lung was assessed on chest x-rays and the oxygenation index was calculated. The major postoperative complications were counted. RESULTS: Interleukin 6 levels were significantly higher in propofol than in sevoflurane group (P=0.014). Preoperative CRP levels did not differ between the groups (P=0.351) and in all patients they were lower than 20 mg/L, but postoperative CRP was significantly higher in propofol group (31±6 vs 15±7 ng/L; P=0.035); Pre- and postoperative procalcitonin was within the reference range (<0.04 µg/L) in both groups. The oxygenation index was significantly lower in propofol group (339±139 vs 465±140; P=0.021). There was no significant difference between the groups in lung infiltrates (P=0.5849). The number of postoperative adverse events was higher in propofol group, but the difference was not-significant (5 vs 1; P=0.115). CONCLUSION: The study suggests an antiinflammatory effect of sevoflurane in patients undergoing thoracotomy with OLV.

A prospective, randomized, double-blinded comparison between multimodal thoracic paravertebral bupivacaine and levobupivacaine analgesia in patients undergoing lung surgery.

OBJECTIVES: To compare the effects of paravertebral analgesia with levobupivacaine or bupivacaine on intra- and postoperative pain for thoracic surgery. DESIGN: A prospective, randomized, and double-blinded study. SETTING: A university hospital. PARTICIPANTS: Forty patients undergoing thoracic surgery. INTERVENTIONS: Patients received paravertebral catheterization and a bolus (14-20 mL) of 0.5% bupivacaine (n = 20) or 0.5% levobupivacaine (n = 20) with morphine, 60 µg/kg, before the induction of general anesthesia that consisted of a propofol infusion. A paravertebral continuous infusion (0.05 mL/kg/h) of 0.25% bupivacaine or 0.25% levobupivacaine, 100 mL, with added morphine, 10 mg, and clonidine, 0.15 mg, was started at the end of surgery for 72 hours postoperatively. Postoperative rescue diclofenac analgesia was available if required. MEASUREMENTS AND MAIN RESULTS: The primary outcome was intraoperative fentanyl consumption. Static and dynamic pain scores measured by a visual analog scale were assessed regularly. Intraoperative fentanyl consumption was significantly lower in the levobupivacaine group compared with the bupivacaine group (p = 0.001). On all 3 postoperative days, static pain scores were significantly lower in the levobupivacaine group compared with the bupivacaine group (p < 0.05). Dynamic pain scores were significantly lower in the levobupivacaine group compared with the bupivacaine group during the 2 postoperative days (p < 0.05). A smaller proportion of patients in the levobupivacaine group used rescue analgesia (p < 0.005). CONCLUSIONS: Paravertebral analgesia with levobupivacaine resulted in less intraoperative fentanyl consumption, lower static (3 days) and dynamic (2 days) pain scores, and less rescue analgesia than analgesia with bupivacaine.

Comparison of continuous thoracic epidural with paravertebral block on perioperative analgesia and hemodynamic stability in patients having open lung surgery.

BACKGROUND: Epidural analgesia can result in perioperative hypotension in patients having thoracotomy. This randomized prospective study assessed the effects of epidural and paravertebral analgesia on hemodynamics during thoracotomy. METHODS: Thirty-two patients were randomized to receive either epidural analgesia (n = 16, 0.25% levobupivacaine and 30 µg/kg morphine) or paravertebral block (n = 16; 0.5% levobupivacaine and 30 µg/kg morphine). Oxygen delivery, stroke volume and systemic vascular resistance indices, heart rate, and mean arterial pressure measurements were performed before administration of local anesthetic, after induction of general anesthesia, institution of 1-lung ventilation, first skin incision, retractor placement, lung-inflation maneuver, and at last skin suture. The primary end point was the volume of the colloid infusion necessary to maintain oxygen delivery index of 500 mL/min per squared meter or higher. Postoperative analgesia was provided immediately after surgery by an infusion of 0.125% levobupivacaine and 20 µg/mL morphine in epidural/paravertebral infusion. Pain, rescue-analgesia consumption, arterial pressure, and heart rate were recorded at 6, 24, and 48 hrs after surgery. Administration of anesthesia and data collection were done by research staff blinded to the regional analgesia technique. RESULTS: The groups did not differ significantly in heart rate, mean arterial blood pressure, or systemic vascular resistance indices. However, to maintain the targeted oxygen delivery index, a greater volume of colloid infusion and phenylephrine were required, respectively, in the epidural than in the paravertebral group (554 ± 50 vs 196 ± 75 mL, P = 0.04; and 40 ± 10 vs 17 ± 4 µg, P = 0.04). Pain intensity before and after respiratory physiotherapy as well as 24 hr rescue piritramide consumption was similar in the epidural (4.1 ± 3.1 mg) and the paravertebral (2.5 ± 1.5 mg) groups (P = 0.14). Systolic blood pressure after 24 and 48 hrs was lower in the epidural group. CONCLUSIONS: Under the conditions of our study, continuous paravertebral block resulted in similar analgesia but greater hemodynamic stability than epidural analgesia in patients having thoracotomy. Paravertebral block also required smaller volume of colloids and vasopressors to maintain the target oxygen delivery index (DO2I).