Hemodynamic Stress Response in Controlled Hypertensive Patients- A Randomized Comparison of I-Scope Video Laryngoscope and Macintosh Laryngoscope

Background: Laryngoscopy and intubation cause activation of the sympathetic nervous system and can results in tachycardia, arrhythmias and hypertension. Hypertensive patients demonstrate a relatively greater rise in catecholamine secretion and an increased sensitivity to them. Aim of the study is to compare the haemodynamic stress response associated with orotracheal intubation using videolaryngoscope or Macintosh laryngoscope in controlled hypertensive patients. Methods: Sixty hypertensive, American Society of Anesthesiologist’s class II, patients were randomly divided in to two groups. In group V (videolaryngoscope), intubation was done with i-scope videolaryngoscope. In group M (Macintosh), intubation was done using Macintosh laryngoscope. Primary objectives of the study pulse rate (PR), systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean blood pressure (MBP) were noted immediately after and at 1, 2, 3, 5 and 10 minutes after intubation. Results: The demographic data were comparable in both groups. There was no significant difference at baseline for mean (SD) PR, SBP, DBP and MBP at baseline and after induction/before intubation (p>0.05). The mean (SD) PR, SBP, DBP and MBP were significantly higher in Macintosh laryngoscope group as compared to i-scope videolaryngoscope immediately after intubation, 1, 2, 3, 5 and 10 minutes after intubation (p<0.001). Conclusion: We found that intubation with the use of i-scope videolaryngoscope results in less haemodynamic stress response than Macintosh laryngoscope in controlled hypertensive patients.

Very severe aortic stenosis masquerading as acute coronary syndrome

Severe aortic stenosis (AS) may rarely present like acute coronary syndrome with increased cardiac biomarker despite having normal coronaries. Here we describe a case of very severe AS, who presented with exertional and rest angina and a high level of TnI. Angiography revealed normal coronaries. Echocardiography showed very severe AS with peak velocity of 5.08 m/s and maximum and mean gradient of 103 and 54 mm Hg, respectively. The patient subsequently underwent aortic valve replacement (AVR) successfully. Subendocardial ischaemia may occur in patients with severe AS during haemodynamic stress, even in the setting of normal unobstructed coronaries due to supply-demand mismatch. Subsequent degeneration and death of the cardiac myocytes cause cTnI elevation, which anticipates the start of the clinical downhill course in severe AS. Our case highlights the importance of thorough physical examination and early use of echocardiography in patients with angina to detect the presence of severe AS.

The molecular signature of high-intensity interval training in the human body

High-intensity training is becoming increasingly popular outside of elite sport for health prevention and rehabilitation. This expanded application of high-intensity training in different populations requires a deeper understanding of its molecular signature in the human body. Therefore, in this integrative review, cellular and systemic molecular responses to high-intensity training are described for skeletal muscle, cardiovascular system, and the immune system as major effectors and targets of health and performance. Different kinds of stimuli and resulting homeostatic perturbations (i.e., metabolic, mechanical, neuronal, and hormonal) are reflected, taking into account their role in the local and systemic deflection of molecular sensors and mediators, and their role in tissue and organ adaptations. In skeletal muscle, a high metabolic perturbation induced by high-intensity training is the major stimulus for skeletal muscle adaptation. In the cardio-vascular system, high-intensity training induces haemodynamic stress and deflection of the Ca2+ handling as major stimuli for functional and structural adaptation of the heart and vessels. For the immune system haemodynamic stress, hormones, exosomes, and O2 availability are proposed stimuli that mediate their effects by alteration of different signalling processes leading to local and systemic (anti)inflammatory responses. Overall, high-intensity training shows specific molecular signatures that demonstrate its high potential to improve health and physical performance.

SEVOFLURANE REQUIREMENT TO ATTENUATE STRESS RESPONSE TO PNEUMOPERITONEUM AND POST-OPERATIVE ANALGESIA DURING LAPAROSCOPIC CHOLECYSTECTOMY: INTRATHECAL DEXMEDETOMIDINE VS. FENTANYL. A PROSPECTIVE RANDOMISED STUDY

Background and aims: Laparoscopic cholecystectomy is considered as the gold standard for cholelithiasis with better preservation of surgical anatomy, early recovery and post-operative analgesia but haemodynamic instability due to pneumo-peritoneum is a concern. This study was contemplated to assess the effect of intrathecal dexmedetomidine or fentanyl on end-tidal inhalation agent concentration requirement as an indirect measure of haemodynamic stress response during the creation of pneumo-peritoneum and on post-operative analgesia. Methods: This prospective, randomized, comparative study was conducted in 75 ASA I and II patients with three groups of 25 each. The patients in group-1 received 10µg of intrathecal dexmedetomidine, group-2 50µg fentanyl and group-3 equal volume of normal saline before administration of general anesthesia. We assessed the vital parameters and end-tidal concentration of sevourane requirement before and 10minutes after creation and immediately after deation of pneumo-peritoneum. Post-operative pain scores were measured using Visual analogue scale(VAS) for 24hrs and rescue analgesia was 0.5µg/kg fentanyl in the immediate post-operative period and paracetamol 15mg/kg if the score was ≥4 in the post-operative period. Results: Demographic data were comparable in all the groups. Systolic blood pressure before onset of pneumo-peritoneum(P=0.03),endtidal inhalation agent concentration to maintain stable haemodynamics post-pneumoperitoneum were signicantly low(P=0.036) in group-1 as compared to group-3. Immediate bolus dose requirement of fentanyl after extubationwas signicantly low, and the duration of post-operative analgesia was prolonged(P=0.009) in group-1.Conclusion: Intrathecal dexmedetomidine may be a safe and effective method in alleviating haemodynamic stress response during pneumo-peritoneum and provides adequate post-operative analgesia in laparoscopic cholecystectomy.

Compare the Effects of Dexmedetomidine Infusion versus Normal Saline as Placebo on Haemodynamic Response in Elective Laparoscopic Surgery Under General Anaesthesia

Background: Throughout the present medical age, laparoscopic surgery is the most effective diagnostic and therapeutic methods. But it is associated with potentially harmful neuroendocrine response. Subjects and Methods: In our study we used dexmedetomidine infusion in group D and normal saline at a rate of 0.4mcg / kg / hr as placebo in group N beginning from 10 minutes before induction before pneumoperitoneum release. Patients in both groups were alike in age, gender, BMI, grade of ASA and anaesthesia. Results: After 10 min infusion of dexmedetomidine and normal saline in group D and group N respectively, fall in HR, DBP and Mean arterial pressure was significantly increased in group D compared to group N. Difference found in both the groups was statistically significant. Group N showed significant increase in HR, SBP, DBP and MAP during laryngoscopy, intubation and at 2 min , 5 min and 10 min after creation of pneumoperitoneum. Difference found was statistically significant in both groups. Thus attenuation in HR, SBP, DBP and MAP was seen in group D as compared to group N during laryngoscopy, tracheal intubation and pneumoperitoneum which were statistically significant. Group N showed statically significant increase in HR, DBP and MAP during extubation compared to group D. Difference found in both the groups was statistically significant. Thus attenuation in HR, DBP and MAP was seen in group D as compared to group N during extubation which was statistically significant. Postoperative sedation score was more in group D compared to group N which was statistically significant. Post-extubation, rescue analgesia was required early in group N compared to group D. Adverse effect in form of bradycardia was seen in 2 patients in group D which did not require atropine administration. Conclusion: Dexmedetomidine infusion at a rate of 0.4 mcg / kg / hr apparently started 10 minutes before the induction of anesthesia before release of pneumoperitoneum without any bolus dose. Useful adjuvant anesthesia to diminish the response of haemodynamic stress to intubation, Pneumoperitoneum, and extubation in laparoscopic surgical patients.

Intradialytic hypotension and relationship with cognitive function and brain morphometry

Background The haemodynamic stress brought about by dialysis could justify the loss of structural and functional integrity of the central nervous system (CNS). The main objective of this study was to analyse the relationship between intradialytic hypotension (IDH) and cognitive function and brain morphometry. Methods The cross-sectional KIDBRAIN study (Cohort Study of Morphological Changes of the Brain by MRI in Chronic Kidney Disease Patients) included 68 prevalent patients with no history of neurological disorders (cerebrovascular disease and cognitive impairment) undergoing haemodialysis (HD). We analysed 18 non-consecutive dialysis sessions (first three of each month over a 6-month period) and various definitions of IDH were recorded. Global cognitive function (GCF) was assessed using the Mini-Mental State Examination (MMSE) and parameters of structural integrity of the CNS were obtained using volume morphometry magnetic resonance imaging analysis [grey matter (GM), white matter (WM) and hippocampus). Results A greater number of sessions with IDH were associated with less volume of WM (r = −0.359,P = 0.003) and hippocampus (r = −0.395, P = 0.001) independent of cardiovascular risk factors according to multivariable linear regression models (β = −0.198, P = 0.046 for WM; β = −0.253, P = 0.017 for hippocampus). The GCF by the MMSE was 27.3 ± 7.3.1 and was associated with WM volume (β = 0.403, P = 0.001) independent of GM and hippocampus volume. Symptomatic IDH was associated with GCF (r = −0.420, P &lt; 0.001) in adjusted analysis (β = −0.339, P = 0.008). Conclusions Even when asymptomatic, IDH is associated with a lower WM and hippocampus volume and reduced GCF in patients undergoing HD, thus suggesting greater vulnerability of the brain to the haemodynamic stress that may be generated by a dialysis session.

Stretch-induced sarcoplasmic reticulum calcium leak is causatively associated with atrial fibrillation in pressure-overloaded hearts

Aims Despite numerous reports documenting an important role of hypertension in the development of atrial fibrillation (AF), the detailed mechanism underlying the pathological process remains incompletely understood. Here, we aim to test the hypothesis that diastolic sarcoplasmic reticulum (SR) Ca2+ leak in atrial myocytes, induced by mechanical stretch due to elevated pressure in the left atrium (LA), plays an essential role in the AF development in pressure-overloaded hearts. Methods and results Isolated mouse atrial myocytes subjected to acute axial stretch displayed an immediate elevation of SR Ca2+ leak. Using a mouse model of transverse aortic constriction (TAC), the relation between stretch, SR Ca2+ leak, and AF susceptibility was further tested. At 36 h post-TAC, SR Ca2+ leak in cardiomyocytes from the LA (with haemodynamic stress), but not right atrium (without haemodynamic stress), significantly increased, which was further elevated at 4 weeks post-TAC. Accordingly, AF susceptibility to atrial burst pacing in the 4-week TAC mice were also significantly increased, which was unaffected by inhibition of atrial fibrosis or inflammation via deletion of galectin-3. Western blotting revealed that type 2 ryanodine receptor (RyR2) in left atrial myocytes of TAC mice was oxidized due to activation and up-regulation of Nox2 and Nox4. Direct rescue of dysfunctional RyR2 with dantrolene or rycal S107 reduced diastolic SR Ca2+ leak in left atrial myocytes and prevented atrial burst pacing stimulated AF. Conclusion Our study demonstrated for the first time the increased SR Ca2+ leak mediated by enhanced oxidative stress in left atrial myocytes that is causatively associated with higher AF susceptibility in pressure-overloaded hearts.