COMPARISON OF DEXMEDETOMIDINE AND FENTANYL ON AIRWAY RESPONSE AND HEMODYNAMICS DURING TRACHEAL EXTUBATION

Background: Extubation is associated with various circulatory and airway responses. Various pharmacological measures including fentanyl and dexmedetomidine have been used to blunt the reflex without compromising the spontaneous respiration. In this study we wanted to compare dexmedetomidine and fentanyl on airway response, smoothness of extubation and hemodynamic changes. Methodology: A total of 68 patients undergoing surgery under general anesthesia with endotracheal intubation, were randomized into two groups. Group A received dexmedetomidine 0.5 mcg/kg and Group B received 1 mcg/kg of fentanyl with the start of skin suturing over a period of 10 minutes via syringe pump. Airway reflex during suction and smoothness of extubation were assessed. Level of sedation during suction, extubation and then every 5 minutes post extubation for 15 minutes were recorded. Hemodynamic parameters were assessed every 5 minutes with start of test solution till extubation and then every 5 minutes for 15 minutes. Results: A total of 68 patients were evaluated in the study. In dexmedetomidine group, 67.6% of patients had no cough on extubation while in fentanyl group 35.3% of patients had no cough on extubation which was statistically significant (p value 0.015). Mean heart rate during extubation increased in both the groups but the increase was 39% in Group B and 11% in Group A from baseline which was statistically significant (p value < 0.001). There was rise in mean systolic and mean arterial pressure during extubation in both the groups but the increase was significantly higher in fentanyl group. Patients in dexmedetomidine group were more sedated but there were no any adverse events. Conclusion: With the results obtained from the study, it is concluded that dexmedetomidine 0.5 mcg/kg over 10 minutes before extubation is effective in alleviating airway response and haemodynamics compared to fentanyl 1 mcg/kg.

Organophosphorus pesticides exhibit compound specific effects in rat precision-cut lung slices (PCLS): mechanisms involved in airway response, cytotoxicity, inflammatory activation and antioxidative defense

Organophosphorus compound pesticides (OP) are widely used in pest control and might be misused for terrorist attacks. Although acetylcholinesterase (AChE) inhibition is the predominant toxic mechanism, OP may induce pneumonia and formation of lung edema after poisoning and during clinical treatment as life-threatening complication. To investigate the underlying mechanisms, rat precision-cut lung slices (PCLS) were exposed to the OP parathion, malathion and their biotransformation products paraoxon and malaoxon (100–2000 µmol/L). Airway response, metabolic activity, release of LDH, cytokine expression and oxidative stress response were analyzed. A concentration-dependent inhibition of airway relaxation was observed after exposure with the oxon but not with the thion-OP. In contrast, cytotoxic effects were observed for both forms in higher concentrations. Increased cytokine expression was observed after exposure to parathion and paraoxon (IL-6, GM-CSF, MIP-1α) and IL-6 expression was dependent on NFκB activation. Intracellular GSH levels were significantly reduced by all four tested OP but an increase in GSSG and HO-1 expression was predominantly observed after malaoxon exposure. Pretreatment with the antioxidant N-acetylcysteine reduced malaoxon but not paraoxon-induced cytotoxicity. PCLS as a 3D lung model system revealed OP-induced effects depending on the particular OP. The experimental data of this study contribute to a better understanding of OP toxicity on cellular targets and may be a possible explanation for the variety of clinical outcomes induced by different OP.

Seasonal dynamics of cold airway hyperresponsiveness in patients with asthma

Introduction. Cold air-induced bronchoconstriction in patients with asthma, leading to a breakdown in disease control, is one of the most serious problems in the northern countries of the world.Aim. To assess the seasonal dynamics of the airway response (ΔFEV1CA) to cold bronchoprovocation in asthma patients with cold airway hyperresponsiveness (CAHR).Materials and methods. Out of 513 asthma patients who underwent primary bronchoprovocation testing, 273 patients (140 women; 133 men) with diagnosed CAHR took part in the retrospective analysis. The design objectification of clinical data using the Asthma Control Test questionnaire (ACT, Quality Metric Inc., 2002), a screening questionnaire for identifying clinical symptoms of response to low ambient temperature in everyday life; assessment of the lung function; bronchoprovocation test of 3-minute isocapnic hyperventilation with cold (-20ºC) air (IHCA).Results. At the time of testing, the average age of patients was 34.8±0.87 years, FEV1 88.5±1.3% of predicted, FEV1/VC 70.9±0.7%; ACT 16 (12; 19) points. On average in the group, ΔFEV1CA was -19.2±0.6%. The frequency of CAHR detection in the winter was 22%, spring – 34%, summer – 22%, autumn – 24% (p>0.05). The minimum changes in FEV1 in response to IHCA were recorded in May-June (mean value ΔFEV1CA -16.2±1.3 and -14.5±1.6%, respectively) and were significantly less in comparison with February (-21.9±2.3%, p˂0.05) and April (-23.0±2.36%, p˂0.01). A correlation has been found between the monthly mean values of meteorological parameters and CAHR, as well as the value of ACT in points and ΔFEV1 (r=0.16; p=0.018).Conclusion. Seasonal changes in the strength of the action of meteorological factors produce a change in the response of the airways to cold bronchoprovocation, and contribute to the loss of asthma control. The maximum values of CAHR fall on February-April, August, November. The data obtained reflect the presence of a complex interaction of physical environmental factors in the induction of seasonal fluctuations of CAHR, which requires a search for specific mechanisms for the formation of altered airway reactivity associated with the characteristics of molecular reception of low temperatures and humidity in the human airways.

Developing a simulation programme to train airway management during the COVID-19 pandemic in a tertiary-level hospital

Tracheal intubation of a patient with COVID-19 is a high-risk procedure for not only the patient, but all healthcare workers involved, leading to an understandable degree of staff anxiety. We used simulation to help train airway managers to intubate patients with COVID-19. Based on action cards developed by our department, we designed a series of scenarios to simulate airway management during the COVID-19 pandemic. Teams were asked to perform a rapid sequence induction with tracheal intubation. We designed in situ scenarios with low-fidelity manikins that could be set up in operating theatres across multiple sites. Over a period of 4 weeks, 101 consultant anaesthetists, 58 anaesthetic trainees and 30 operating department practitioners received intubation training. These members made up the airway response team of our hospital. 30 emergency department doctors also received training in anticipation of further COVID-19 surges leading to the possibility of overwhelmed services. Simulation-based training was an invaluable tool for our hospital to rapidly upskill medical professionals during the first wave of the COVID-19 pandemic. We have used feedback and additional guidelines to improve our scenarios to retrain staff during subsequent waves.

Dexmedetomidine versus Lignocaine for extubation in patients undergoing craniotomies

Use of lignocaine and dexmedetomidine in terms of causing hemodymaic variation, sedation and pain management remains a question. Hence this was conducted to compare a bolus dose of dexmedetomidine 0.5mcg/kg/hr to a normal dose of 1.5mg/kg preservative free 2% lignocaine for extubation in patients undergoing craniotomies.This randomized controlled trial was conducted in the department of Anesthesiology at Sri Ramachandra Medical College and Research Institute, Chennai from January 2013 to June 2014. Patients aged between 18-60 years belongs to ASA class I and class II undergoing surgeries were included in the study. A total of fifty cases were included. Statistical analysis was done using SPSS version 17.Hemodynamic parameters showed significant attenuation of hemodynamic response during extubation when compared to lignocaine group and when the same were analyzed within the groups, the attenuation of extubation response was both clinically and statistically significant in both groups. Extubation and emergence time were similar in both the groups. Sedation and pain scores in dexmedetomidine group were low compared to lignocaine group. Single dose of dexmedetomidine given 10 minutes before extubation significantly attenuated the hemodynamic and airway response following extubation as compared to lignocaine given before reversal in patients undergoing craniotomy for intracranial space occupying lesions.