Effects of helium-oxygen on respiratory mechanics, gas exchange, and ventilation-perfusion relationships in a porcine model of stable methacholine-induced bronchospasm

Objective: To explore the consequences of helium/oxygen (He/O2) inhalation on respiratory mechanics, gas exchange, and ventilation-perfusion (VA/Q) relationships in an animal model of severe induced bronchospasm during mechanical ventilation. Design: Prospective, interventional study. Setting: Experimental animal laboratory, university hospital. Interventions: Seven piglets were anesthetized, paralyzed, and mechanically ventilated, with all ventilator settings remaining constant throughout the protocol. Acute stable bronchospasm was obtained through continuous aerosolization of methacholine. Once steady-state was achieved, the animals successively breathed air/O2 and He/O2 (FIO2 0.3), or inversely, in random order. Measurements were taken at baseline, during bronchospasm, and after 30min of He/O2 inhalation. Results: Bronchospasm increased lung peak inspiratory pressure (49±6.9 vs 18±1cmH2O, P<0.001), lung resistance (22.7±1.5 vs 6.8±1.5cmH2O.l−1.s, P<0.001), dynamic elastance (76±11.2 vs 22.8±4.1cmH2O.l−1, P<0.001), and work of breathing (1.51±0.26 vs 0.47±0.08, P<0.001). Arterial pH decreased (7.47±0.06 vs 7.32±0.06, P<0.001), PaCO2 increased, and PaO2 decreased. Multiple inert gas elimination showed an absence of shunt, substantial increases in perfusion to low VA/Q regions, and dispersion of VA/Q distribution. He/O2 reduced lung resistance and work of breathing, and worsened hypercapnia and respiratory acidosis. Conclusions: In this model, while He/O2 improved respiratory mechanics and reduced work of breathing, hypercapnia and respiratory acidosis increased. Close attention should be paid to monitoring arterial blood gases when He/O2 is used in mechanically ventilated acute severe asthm

NSAID analgesic ketorolac used perioperatively may suppress early breast cancer relapse: particular relevance to triple negative subgroup

To explain a bimodal relapse hazard among early stage breast cancer patients treated by mastectomy we postulated that relapses within 4 years of surgery resulted from something that happened at about the time of surgery to provoke sudden exits from dormant phases to active growth. Relapses at 10 months appeared to be surgery-induced angiogenesis of dormant avascular micrometastases. Another relapse mode with peak about 30 months corresponded to sudden growth from a single cell. Late relapses were not synchronized to surgery. This hypothesis could explain a wide variety of breast cancer observations. We have been looking for new data that might provide more insight concerning the various relapse modes. Retrospective data reported in June 2010 study of 327 consecutive patients compared various perioperative analgesics and anesthetics in one Belgian hospital and one surgeon. Patients were treated with mastectomy and conventional adjuvant therapy. Follow-up was average 27.3 months with range 13–44 months. Updated hazard as of September 2011 for this series is now presented. NSAID ketorolac, a common analgesic used in surgery, is associated with far superior disease-free survival in the first few years after surgery. The expected prominent early relapse events are all but absent. In the 9–18 month period, there is fivefold reduction in relapses. If this observation holds up to further scrutiny, it could mean that the simple use of this safe and effective anti-inflammatory agent at surgery might eliminate most early relapses. Transient systemic inflammation accompanying surgery could be part of the metastatic tumor seeding process and could have been effectively blocked by perioperative anti-inflammatory agents. In addition, antiangiogenic properties of NSAIDs could also play a role. Triple negative breast cancer may be the ideal group with which to test perioperative ketorolac to prevent early relapses

Publication Preview Source A Randomized Controlled, Double-Blind Trial Evaluating the Effect of Opioid-Free Versus Opioid General Anaesthesia on Postoperative Pain and Discomfort Measured by the QoR-40

Journal of Clinical Anesthesia and Pain Medicinewww.scientonline.orgJ Clin Anesth Pain MedVolume 2 • Issue 1 • 015Research ArticleA Randomized Controlled, Double-Blind Trial Evaluating the Effect of Opioid-Free Versus Opioid General Anaesthesia on Postoperative Pain and Discomfort Measured by the QoR-40Jan P Mulier1 2 3*, Ruben Wouters1 2, Bruno Dillemans4, Marc Dekock51Departement of Anaesthesiology, AZ Sint Jan Brugge-Oostende, B-8000 Brugge, Belgium2KU Leuven - University of Leuven, B-3000 Leuven, Belgium3UGent - University of Gent, B-9000 Gent, Belgium4Department of general surgery AZ Sint Jan Brugge-Oostende, B-8000 Brugge, Belgium5Department of anaesthesiology, CHWAPI, Tournai, B-7500 BelgiumIntroductionBefore the introduction of synthetic opioids in the 1960s, sympathetic block was achieved in anaesthesia by giving more hypnotic agents than required to achieve hypnosis. Fluothane and thiopental induced strong hemodynamic suppression creating a hypotension [1,2]. Lidocaine and procaine have been added intravenously at high doses (4.5 mg/kg [3] to 9 mg/kg [4]) to suppress laryngeal reactions with fewer hemodynamic problems. Synthetic opioids that can be given at a high dose, without inducing histamine release, suppress the sympathetic system with less hemodynamic instability [5,6]. Opioids are the strongest analgesics available and therefore assumed to be an essential part of balanced anaesthesia [7].Sympathetic and parasympathetic suppression can be achieved today with loco-regional anaesthesia or by several non-opioid drugs. Opioid free general anaesthesia can be achieved with 50 mg ketamine given after propofol and before incision in spontaneous breathing patients like for plastic surgery [8]. The alpha-2 agonists [9] suppress better the sympathetic system and can replace opioids for sympathetic stabilization in major surgery [10,11]. A high-dose alpha-2 agonist *Corresponding Author: Jan P. Mulier, Department of Anaesthesiology, AZ Sint Jan Brugge-Oostende, Ruddershove 10, 8000 Bruges, Belgium, Email: [email protected] article was published in the following Scient Open Access Journal:Journal of Clinical Anesthesia and Pain MedicineReceived January 31, 2018; Accepted February 07, 2018; Published February 15, 2018 AbstractThis study measured post-operative opioid consumption and quality of recovery after Opioid-Free Anaesthesia (OFA).50 Patients undergoing elective laparoscopic bariatric surgery were randomised in two groups. Before induction, the Opioid Anaesthesia (OA) group received 0.5 mcg/kg sufentanil, while the OFA group received 0.5 mcg/kg dexmedetomidine, 0.25 mg/kg ketamine, and 1.5 mg/kg lidocaine. Anaesthesia was induced with propofol and rocuronium and the bispectral index was maintained in both groups between 40% and 60% by adapting end-tidal sevoflurane. Anaesthesia was further maintained with sufentanil or lidocaine and dexmedetomidine. Postoperative analgesia was achieved with 4 g/day paracetamol and with patient-controlled 2-mg morphine. Kalkman and APAIS were measured before anaesthesia. QoR-40, VAS, morphine consumption and cortisol levels were measured postoperatively.The post-operative opioid consumption was lower in the PACU and quality of recovery was higher next day after OFA versus OA. There were no differences between the two groups regarding age, weight, height, body mass index, gender, information desire, and incidence of obstructive sleep apnoea syndrome, combined anxiety score, and Kalkman points. No differences were found in the number of patients having had one or more intra operative hemodynamic problems. Post-operative major adverse events, like hypertension and bleeding, were significant higher in the OA group.Postoperative saturation in the post-anaesthesia care unit while giving a 6 l/min O2 mask was lower in the OA group with a higher incidence of hypertension, postoperative nausea and vomiting, shivering or feeling cold and a higher VAS score. The following morning patients in the OFA group had higher QoR-40 scores and lower VAS scores cortisol levels.Keywords: Opioid free general anaesthesia, Laparoscopic bariatric surgery, Randomized controlled clinical trial, Quality of recovery (QoR-40), Enhanced recovery after surgery (ERAS), Post-operative pain and discomfort (PDF) A Randomized Controlled, Double-Blind Trial Evaluating the Effect of Opioid-Free Versus Opioid General Anaesthesia on Postoperative Pain and Discomfort Measured by the QoR-40. Available from: https://www.researchgate.net/publication/323425051_A_Randomized_Controlled_Double-Blind_Trial_Evaluating_the_Effect_of_Opioid-Free_Versus_Opioid_General_Anaesthesia_on_Postoperative_Pain_and_Discomfort_Measured_by_the_QoR-40 [accessed Jan 12 2019].status: Published onlin

Effects of helium-oxygen on respiratory mechanics, gas exchange, and ventilation-perfusion relationships in a porcine model of stable methacholine-induced bronchospasm.

OBJECTIVE: To explore the consequences of helium/oxygen (He/O(2)) inhalation on respiratory mechanics, gas exchange, and ventilation-perfusion (VA/Q) relationships in an animal model of severe induced bronchospasm during mechanical ventilation. DESIGN: Prospective, interventional study. SETTING: Experimental animal laboratory, university hospital. INTERVENTIONS: Seven piglets were anesthetized, paralyzed, and mechanically ventilated, with all ventilator settings remaining constant throughout the protocol. Acute stable bronchospasm was obtained through continuous aerosolization of methacholine. Once steady-state was achieved, the animals successively breathed air/O(2) and He/O(2) (FIO(2) 0.3), or inversely, in random order. Measurements were taken at baseline, during bronchospasm, and after 30 min of He/O(2) inhalation. RESULTS: Bronchospasm increased lung peak inspiratory pressure (49+/-6.9 vs 18+/-1 cm H(2)O, P<0.001), lung resistance (22.7+/-1.5 vs 6.8+/-1.5 cm H(2)O x l(-1).s, P<0.001), dynamic elastance (76+/-11.2 vs 22.8+/-4.1 cm H(2)O x l(-1), P<0.001), and work of breathing (1.51+/-0.26 vs 0.47+/-0.08, P<0.001). Arterial pH decreased (7.47+/-0.06 vs 7.32+/-0.06, P<0.001), PaCO(2) increased, and PaO(2) decreased. Multiple inert gas elimination showed an absence of shunt, substantial increases in perfusion to low VA/Q regions, and dispersion of VA/Q distribution. He/O(2) reduced lung resistance and work of breathing, and worsened hypercapnia and respiratory acidosis. CONCLUSIONS: In this model, while He/O(2) improved respiratory mechanics and reduced work of breathing, hypercapnia and respiratory acidosis increased. Close attention should be paid to monitoring arterial blood gases when He/O(2) is used in mechanically ventilated acute severe asthma

Adult liver transplantation: UCL experience

OBJECTIVE: To evaluate the impact of standardized operative and peri-operative care on the outcome of liver transplantation in a single center series of 395 adult patients. METHOD AND MATERIAL: Between February 1984 and December 31, 1998, 451 orthotopic liver transplantations were performed in 395 adult patients (> or = 15 years) at the University Hospitals St-Luc in Brussels. Morbidity and mortality of the periods 1984-1990 (Gr I--174 pat.) and 1991-1998 were compared (Gr II--221 pat.). During the second period anti-infectious chemotherapy and perioperative care were standardized and surgical technique changed from classical orthotopic liver transplantation with recipients' vena cava resection (and use of veno-venous bypass) towards liver implantation with preservation of the vena cava (without use of bypass). Immunosuppression was cyclosporine based from 1984 up to 1996 and tacrolimus based during the years 1997 and 1998. Immunosuppression was alleviated during the second period due to change from quadruple to triple and even double therapy and due to the introduction of low steroid dosing and of steroid withdrawal, once stable graft function was obtained. Indications for liver grafting were chronic liver disease (284 pat--71.9%), hepatobiliary tumor (52 pat--13.2%), acute liver failure (40 pat--10.1%) and metabolic disease (19 pat--4.8%). Regrafting was necessary because of graft dysfunction (21 pat), technical failure (12 pat), immunological failure (18 pat) and recurrent viral allograft disease (5 pat); three of these patients were regrafted at another institution. Follow-up was complete for all patients with a minimum of 9 months. RESULTS: Actuarial 1, 5 and 10 years survival rates for the whole group were 77.9%, 65.7% and 58.3%. These survival rates were respectively 77.3%, 69.7%, 62.5% and 73.2%, 59.6% 51.4% for benign chronic liver disease and acute liver failure; those for malignant liver disease were 80.6%, 44.3% and 36.7%. Early ( 3 months) posttransplant mortalities were. 14.4% (57 pat) and 21.2% (84 pat). Early mortality lowered from 20% in Gr I to 9.4% in Gr II (p < 0.02); this was due to a significant reduction during the second period of bacterial (99/174 pat.--56.9% vs 82/221 pat.--37.1%), fungal (14 pat.--8% vs 7 pat.--3.2%) and viral (87 pat.--50% vs 49 pat.--22.2%) infections (p < 0.05) as well as of perioperative bleeding (92 pat.--52.9% vs 39 pat.--17.6%--p < 0.001). Late mortality remained almost identical throughout the two periods as lethal outcome was mainly caused by recurrent allograft diseases, cardiovascular and tumor problems. Morbidity in these series was important considering that almost, half of the patients had a technical complication, mostly related to bleeding (131 pat--33.2%) and biliary problems (66 pat--16.7%). Retransplantation index was 1.1 (54 pat.--14%). Early retransplantation mortality was 24%; it lowered, although not yet significantly, during the second period (8/25 pat.--32% vs. 5/29 pat.--17.2%). CONCLUSION: Despite a marked improvement of results, liver transplantation remains a major medical and surgical undertaking. Standardization of operative and perioperative care, less haemorraghic surgery and less aggressive immunosuppression are the keys for further improvement