Induction Dose Of Propofol Research Articles

Effects of different dexmedetomidine doses on haemodynamic variability during laryngoscopy and intubation: A randomized double-blind study

Background: Effective airway management is vital in anesthesiology for preserving patient lives. Laryngoscopy and endotracheal intubation, commonly used procedures, can lead to undesirable outcomes due to vagal activation and sympathoadrenal reaction. This double-blind, randomized interventional study aimed to assess the impact of two different doses of dexmedetomidine on heart rate and blood pressure during laryngoscopy and intubation, which often induce tachycardia and hypertension, particularly risky for patients with hypertension, myocardial insufficiency, and cerebrovascular disease. Methods: Seventy-six participants, aged 20-60 years and classified as American Society of Anesthesiologists (ASA) Grade I & II, were enrolled after Institutional Ethics Committee approval. Random allocation assigned them to two groups: Group A (0.5 µg/kg dexmedetomidine) and Group B (1.0 µg/kg dexmedetomidine) before anesthesia induction. Hemodynamic measurements were recorded at various time points: pre- and post-drug administration, before intubation, and at intervals thereafter. Results: Both groups exhibited similar age, weight, and gender distribution. Group B consistently demonstrated lower hemodynamic variables compared to Group A after laryngoscopy and intubation. Additionally, Group B required a smaller induction dose of propofol than Group A. No significant adverse effects were reported in either group during the study. Conclusion: The study suggests that intravenous administration of dexmedetomidine at a rate of 1 µg/kg is more effective than 0.5 µg/kg in attenuating the physiological response to laryngoscopy and intubation. Moreover, it reduces the required propofol dose for anesthesia induction. These findings highlight the potential benefits of higher dexmedetomidine doses in mitigating adverse physiological effects during airway management procedures

Propofol Infusion Versus Isoflurane/Nitroglycerine Combination for Controlled Hypotensive Anesthesia in Neurosurgery

Background: The use of hypotensive anesthesia is one of several techniques that have been used to lessen the intraoperative loss of blood and improve visibility in the operative field. A procedure that requires a clear area and little intraoperative bleeding, which can affect the surgeons' abilities, is Neurosurgery. Objective: The current study aimed to assess how both anesthetics affected tissue perfusion, blood loss, operating field visibility, and extubation time. Settings and Design: A prospective quasi-experiment was used in the design of this clinical trial Practical Implication: The practical implication for choosing between propofol infusion and the isoflurane/nitroglycerine combination for controlled hypotensive anesthesia in neurosurgery includes considering several factors. Firstly, the patient's individual characteristics and medical history should be taken into account to determine the most suitable anesthesia approach. Secondly, the surgical procedure and the desired level of hypotension required should be evaluated. Thirdly, the availability and expertise of the anesthesia team in managing either method should be considered. Finally, potential side effects and complications associated with each technique should be weighed. Ultimately, a well-informed decision must be made based on these considerations to ensure the safety and efficacy of controlled hypotensive anesthesia in neurosurgery. Patients and Methods: Sixty individuals with ASA I or II were separated into two groups; Group P received both induction and maintenance doses of propofol, while Group I received isoflurane for maintenance with nitroglycerine. Blood loss, heart rate, mean arterial pressure, and the degree of surgical field clarity were all monitored every ten minutes. Results: As opposed to the isoflurane group, the propofol group substantial reduction in blood loss (p=0.01), improved clarity of the surgical field (p=0.002), and reduced time to extubation (p=0.001). Conclusion: Even with the addition of the hypertension medication nitroglycerine to isoflurane, propofol for craniotomy improved surgical conditions and gave a quicker recovery than isoflurane. Keywords: Nitroglycerin, Isoflurane, Propofol, Hypotensive Anesthesia, and Neurosurgery

Propofol and thiopental for intravenous induction in neonates: study protocol for a dose-finding trial.

Propofol and thiopental are commonly used induction agents in neonatal anesthesia. Even though both hypnotics have been used off-label for many years, pharmacological knowledge regarding these agents is scarce in neonates. The significant variability in neonates' body composition, organ function, and maturation makes pharmacological studies highly relevant albeit challenging. As a result, there is currently limited data about the anesthetic induction dose of thiopental and propofol in neonates. In addition, a knowledge gap exists concerning the pharmacodynamics of induction doses. To determine the median effective anesthetic induction dose of propofol and thiopental in neonatal patients of different gestational and postnatal ages and evaluate the pharmacodynamics of the anesthesia induction doses on the neonatal systemic and cerebral hemodynamics. This is a single-center, prospective, open-label, interventional, dose-finding study, including neonatal patients from birth up to 28 postnatal days undergoing general anesthesia for surgical or diagnostic procedures. The patients will be stratified according to their gestational and postnatal age and allocated to one of the two trial arms: anesthesia induction with propofol or anesthesia induction with thiopental. We will use Dixon's up-and-down method to estimate the median effective anesthesia induction dose of both agents in neonates of different gestational and postnatal ages. In addition, we will study the relationship between anesthesia induction doses and changes in systemic and cerebral hemodynamics. Alterations in the systemic and cerebral regional hemodynamics secondary to anesthesia induction may be harmful in neonates, especially premature and critically ill newborns, due to their immature organ systems, reduced physiological reserves, and impaired cerebral autoregulation. Perfusion homeostasis is considered one of the significant and modifiable determinants of anesthesia-related neurocognitive outcomes. Therefore, dose-finding and safety pharmacological studies of the anesthetic induction agents in neonates are urgently needed and acknowledged as a high priority by the European Medicine Agency. Estimating adequate induction doses to ensure optimal depth of anesthesia while avoiding systemic and cerebral hemodynamic disturbances will help ensure safe anesthesia and potentially improve anesthesia-related outcomes in this group of patients. This article is protected by copyright. All rights reserved.

Comparison between patient state index, bispectral index, and clinical parameters for propofol induction in Indian patients: A prospective study.

Patient state index (PSI) and bispectral index (BIS) are depth of anesthesia monitors utilized for the dosage of propofol usage for induction. We compare PSI, BIS, and Observer's Assessment of Alertness/Sedation Scale (OAA/S) for propofol dose usage for induction. Seventy-four ASA I and II patients, aged 18-65 years scheduled for laparoscopic cholecystectomy were included and divided into groups to titrate the drug dosage of propofol needed for induction of anesthesia, monitored by PSI (Group A), BIS (Group B), or clinical OAA/S (Group C). The drug dosage needed for induction was based on a PSI value of 25 ± 2, BIS value of 48 ± 2, and OAA/S value of ≤2 as the endpoint of induction in respective groups. Intraoperative hemodynamic variables and any complications were compared. The mean doses of propofol needed for induction were 2.23 mg/kg (Group A), 2.05 mg/kg (Group B), and 2.11 mg/kg (Group C). A significantly decreased dose was needed to achieve the desired end in Group B compared to Group A (P = 0.01). The hemodynamic variables such as heart rate, systolic blood pressure, and diastolic blood pressure among the three groups were comparable. The clinical method of titrating the dose of propofol for induction and anesthetic depth by the loss of verbal response is comparable to both BIS and PSI monitoring.

Comparison of Dexmedetomidine with Midazolam as an adjuvant with Propofol for insertion of ProSeal laryngeal mask airway in Children.

Propofol is required in higher doses for smooth insertion of the ProSeal laryngeal mask airway. The ideal adjuvant drug so as to minimise induction doses of propofol is still not known. Dexmedetomidine and midazolam are equally effective for premedication in children. We have designed this study to compare dexmedetomidine and midazolam as adjuvants with propofol for insertion characteristics of ProSeal laryngeal mask airway. A total of 130 paediatric patients undergoing elective surgery were randomly allocated into 2 groups of 65 each. One group was induced using propofol, fentanyl and midazolam, whereas the other group received propofol, fentanyl and dexmedetomidine. Subsequently, insertion characteristics of ProSeal laryngeal mask airway were documented in terms of number of attempts and by using modified Muzi score. Post-operative sedation was recorded by Ramsay Sedation Scale and pain was assessed by using Wong-Baker Faces pain scale. Out of 130 patients, ProSeal laryngeal mask airway was inserted in a second attempt in only 5 patients of midazolam group. Time taken for insertion was significantly higher among the midazolam group (21 seconds) than the dexmedetomidine group (19 seconds). A total of 93.8% of patients administered dexmedetomidine had excellent Muzi scores in comparison to midazolam group where only 13.8% patients had excellent Muzi scores (P < .001). Dexmedetomidine in a dose of 1 μg kg-1 as compared to midazolam (20 μg kg-1) produces better insertion characteristics for ProSeal laryngeal mask airway when used as adjuvant with propofol in terms of jaw opening, ease of insertion, coughing, gagging, patient movement, and laryngospasm.

Efficacy of dexmedetomidine in attenuating pressor response to laryngoscopy and endotracheal intubation under bispectral index controlled anesthesia: a prospective randomized double-blinded study

BackgroundLaryngoscopy and endotracheal intubation may lead to a remarkable hemodynamic pressor response. Dexmedetomidine, an α2-adrenergic receptor agonist, can be effectively used to attenuate this pressor effect. This study was aimed to compare the efficacy of two different doses of dexmedetomidine (0.5 µg/kg and 1.0 µg/kg) in attenuation of hemodynamic pressor response to largyngoscopy and endotracheal intubation under bispectral index (BIS) monitoring. One hundred twenty adult patients with American Society of Anesthesiologists (ASA) physical status I or II posted for various elective surgeries under general anesthesia were enrolled to receive an intravenous (IV) infusion of dexmedetomidine 0.5 μg/kg (group D1; n = 40), 1.0 μg/kg (group D2; n = 40) or normal saline over 15 min (group C; n = 40). The primary outcome measure was to assess the hemodynamic changes while the secondary outcome measures were to assess sedation, dose of propofol required for induction and side effects.ResultsThe mean HR, SBP, DBP, and MAP remained significantly lower in both dexmedetomidine groups as compared to control group after study drug infusion, after induction, at and after intubation (P < 0.05). Group D2 also had significantly lower mean HR, SBP, DBP, and MAP in comparison to group D1 (P < 0.05). The induction dose of propofol was significantly less in dexmedetomidine groups as compared to control group (P < 0.05). Ramsay sedation scale (RSS) score was found to be significantly more in both groups D1 and D2 after study drug infusion (P<0.001). No significant difference was noted in incidence of side effects (P = 0.907).ConclusionsDexmedetomidine (0.5 µg/kg and 1.0 µg/kg) was found to be effective in attenuating the hemodynamic pressor response to laryngoscopy and endotracheal intubation with BIS monitoring.Trial registrationCTRI, CTRI/2020/03/024088. Registered 19 March 2020.

EFFECT OF NEBULISED DEXMEDETOMIDINE IN BLUNTING HAEMODYNAMIC RESPONSE TO INTUBATION- A RANDOMIZED DOUBLE BLIND CONTROLLED STUDY

BACKGROUND: Dexmedetomidine, an alpha-2 agonist, has been used for attenuation of he- modynamic response to laryngoscopy but not through the nebulized route. We evaluated the effects of preoperative dexmedetomidine nebulization on the hemodynamic response to laryngoscopy and intubation. To evaluate the AIM: effects of nebulised dexmedetomidine as a premedication in Blunting the haemodynamic response to laryngoscopy and tracheal intubation. After MATERIALS AND METHODS: written informed consent and ethics committee approval, 50 patientsBelonging to ASA status I or II were randomly allocated to two groups.Patients not Giving consent,predicted airway difculty and uncontrolled hypertension were Excluded. All the patients were monitored by ASA standard monitors.They were Randomized into two groups- C and D Group C received 5 ml of normal saline and Group D received 5 ml of dexmedetomidine at a dose of 1 μg/kg as nebulisation 10 mins prior to induction.Then the patients were premedicated and induced with Propofol and intubated after giving a non depolarizing muscle relaxant. Vital monitoring like HR,SBP,DBP,MAP,SPO2,was noted at baseline, post nebulization ,post intubation at 1,5,10 minutes. Demographic details and surgery cha RESULTS: racteristics were comparable between the Groups.Heart rate between the two groups were comparable.The MAP,SBP and DBP values after intubation were lower in group D, which was statistically Signicant(P&lt;0.05).The mean dose of propofol for induction was also lower in Group D. To conclude,nebulised CONCLUSION: dexmedetomidine effectively blunts the pressor response To laryngoscopy and intubation with no serious adverse effects

Fentanilo para la coinducción de la anestesia con propofol en perros premedicados con morfina

The aim of the present study was to evaluate the effectiveness of fentanyl to reduce the induction dose of propofol and the quality of induction in dogs premedicated with morphine. The sedative effect promoted by morphine and its action on some physiological variables were also investigated. Twenty-two healthy dogs had their baseline values (BL) of the physiological variables and the degree of sedation recorded. Then, received morphine (0.3 mg/kg) intramuscularly. Ten minutes after morphine administration (T10), all variables were reassessed. Dogs were randomly assigned to receive intravenously: fentanyl (2.5 µg/kg) or saline (3.0 mL), followed by propofol (2 mg/kg/minute), groups FP and SP, respectively. The dose of propofol required for intubation and the quality of anesthetic induction were recorded. Morphine administration resulted in vomiting and no sedation. Heart rate significantly decreased at T10 in FP and in SP groups, compared to BL. The total dose of propofol used for anesthetic induction was 6.4 ± 1.7 and 5.8 ± 1.6 [mean ± standard deviation] mg/kg in FP and SP, respectively, with no differences between groups (P &gt; 0.05). The quality of anesthetic induction score was excellent in all groups. During anesthetic induction, some dogs had apnea and muscle stiffness. Fentanyl was not effective in reducing the propofol requirement in the anesthetic induction of dogs premedicated with morphine. Anesthetic induction was excellent in both groups, and may be accompanied by apnea and muscle stiffness. Morphine resulted in no sedation, minimal changes in physiological parameters and vomiting.

Comparison of Half-Effective Concentration of Propofol in Patients with Parkinson's Disease and Non-Parkinson's Disease.

This study aimed to compare the half-effective concentration (EC50) of propofol required for the bispectral index (BIS) 50 in patients with Parkinson's disease (PD) and non-PD (NPD) during induction by the Dixon's improved sequential method. This prospective study recruited 20 patients with PD undergoing deep brain stimulation and 20 patients with NPD accompanied by meningioma or glioma undergoing intracranial surgery from March 2018 to March 2019. The patients were induced by propofolviatarget-controlledinfusion. The targeteffect-siteconcentrationof propofol was determined by the Dixon's improved sequential method. The results of the pilot experiment showed that the targeteffect-site concentration for the first patient with PD and NPD was 3.5 µg/mL and 2.8 µg/mL, respectively. BIS values were recorded after achievingaconstanteffect-siteconcentrationof propofol. The increment or decrement of the targeteffect-site concentration of the next patient was 0.1 µg/mL. Demographic data, general physical condition, and hemodynamic values were similar between the PD and the NPD groups. The targeteffect-siteconcentrationof propofol induction doses was significantly higher in the PD group than in the NPD group. The EC50 of propofol required for BIS 50 was 3.213 µg/mL [95% confidence interval (CI), 3.085-3.287 µg/mL] in the PD group and 2.77 µg/mL (95% CI, 2.568-2.977 µg/mL) in the NPD group. The EC50 of propofol required for BIS 50 was higher in patients with PD than in patients with NPD.

The induction dose of Propofol, while using either Ketamine or Midazolam as co-induction agent

The induction dose of Propofol, while using either Ketamine or Midazolam as co-induction agent

Effects of oral melatonin premedication on hemodynamic responses to intubation, anesthetic requirements and postoperative sedation: A randomized trial.

Sedative effects of melatonin may have an additive effect on general anesthesia (GA). We compared hemodynamic response to intubation following oral premedication with melatonin versus placebo. Induction dose of propofol, isoflurane and fentanyl consumption were also compared. This prospective, double-blinded study was conducted in fifty patients randomized into two equal groups. Group M received oral melatonin 6 mg and group P a placebo two hours before surgery. All patients were induced with intravenous propofol of 1.5-2.5mg/kg till loss of response to verbal commands, three minutes after vecuronium, laryngoscopy was done and trachea was intubated. Heart rate (HR) and mean arterial pressures (MAP) were recorded before premedication, before induction, immediately after induction and then at 1,3,5 and 10 minutes after intubation. Mean HR was comparable in both groups throughout the study period. Group M had significantly lower MAP before induction and immediately after induction (P < 0.05). At all other time points MAP remained comparable in both groups. Mean isoflurane consumption was significantly lower in group M compared to group P (14.8 ± 4.2 vs 19.7 ± 3.2 mL). Propofol requirement for induction was also significantly lower in group M (102.4 ± 19.6 vs 122.4 ± 26.3mg). Intraoperative fentanyl consumption was comparable. Oral premedication with melatonin 6mg administered two hours before surgery significantly reduced MAP before and after induction of GA with a significant reduction in dose of propofol requirement. Titrating induction dose of propofol till loss of response to verbal commands did not effectively attenuate responses to laryngoscopy and intubation following melatonin oral premedication.

Comparison of propofol infusion rate required to abolish swallowing or pedal withdrawal reflexes in dogs.

In a prospective, randomized, experimental non-blinded study, the continuous infusions rates of propofol required to prevent swallowing (P-SR) or pedal withdrawal reflex (P-WR) were evaluated in healthy premedicated dogs. Dogs were randomly assigned to one of two treatments at weekly intervals. Following premedication with a combination of acepromazine and methadone, anesthesia was induced with propofol (4.00 mg kg-1 per min) and was maintained for 90 min. The propofol infusion rate was increased or decreased by 0.05 mg kg-1 per min based on positive or negative swallowing (P-SR) or pedal withdrawal reflexes (P-WR). Propofol induction doses were 2.12 ± 0.43 mg kg-1 (P-SR) and 2.14 ± 0.31 mg kg-1 (P-WR), which were not significantly different. The mean (±SD) propofol infusion rate was significantly higher for P-WR (0.26 ± 0.10 mg kg-1 per min) when compared to P-SR (0.22 ± 0.12 mg kg-1 per min). During the last 30 min, the mean propofol infusion rates were 0.09 ± 0.02 and 0.18 ± 0.03 mg kg-1 per min for P-SR and P-WR, respectively. There were no significant differences between treatments with respect to heart rate (HR), respiratory rate, arterial blood pressure, end-tidal CO2 partial pressure, hemoglobin oxygen saturation, partial pressures of oxygen or pH. Transient apnea lasting up to three minutes was observed in three dogs with each treatment. Propofol infusion rate of 0.22 ± 0.12 mg kg-1 per min can be used in premedicated dogs requiring tracheal intubation and undergoing mechanical ventilation, non-painful procedures or painful procedures with local anesthetic techniques.

ANESTHETIC PROPERTIES OF PROPOFOL AND KETOFOL (KETAMINE WITH PROPOFOL): A COMPARATIVE STUDY

Background: Surgical procedures require a safe anesthesia and safe anesthetic agents for this purpose use of small dose of sedative agent or any other anesthetic agent in order to reduce the dose requirement as well as adverse effects of the main inducing agent. Therefore, this study was carried out using ketamine with propofol (KETOFOL) to compare the hemodynamic stability (Heart rate and Mean arterial pressure) and induction doses. Methods: Fifty patients of age 18 to 60 years of ASA II and I scheduled for elective surgery to be performed under general anaesthesia were randomly selected and divided into two groups. Patient in Group-P received 50 mg propofol and Group-K received 50 mg (25mg ketamine with 25 mg propofol) intravenously bolus slowly and then 10 mg in every 10 seconds until the loss of eyelash reflex and verbal response. The hemodynamic response was noted at different given time. Chi square test and student’s t test were used for analysis. Results: The study showed that the hemodynamic (heart rate and mean arterial pressure) was maintained and decrease in dose requirement for propofol for induction in (ketamine with propofol Ketofol group whereas there was significant decrease in hemodynamic (heart rate and mean arterial pressure) in Propofol group. Conclusions: Our study concluded that fluctuations in heart rate and mean arterial pressure from baseline were more in propofol group compared to ketofol (ketamine with propofol) group. Therefore, Ketofol achieved better hemodynamic stability over propofol alone and also induction dose of propofol was reduced.

Propofol/Etomidate Induced and Isoflurane Maintained Anaesthesia in Dogs

Twenty-four clinical cases of dogs presented for surgical interventions requiring general anaesthesia were randomly divided into four groups (n=6) irrespective of age, breed, sex, body weight and surgical procedure. The animals of group I and II were first premedicated with atropine sulphate @ 0.02 mg/kg BW and butorphanol @ 0.2 mg/kg BW intramuscularly; whereas, atropine sulphate @ 0.02 mg/kg BW and buprenorphine @ 0.02 mg/kg BW was administered intramuscularly in animals of group III and IV, followed by diazepam @ 0.5 mg/kg BW intravenously in all the dogs. Induction of anaesthesia was achieved by intravenous administration of 1% propofol in group I and III and 0.2 % etomidate in group II and IV till effect. Dose sparing effect of pre-anaesthetic drugs, anaesthetic duration, viz., duration of surgery, duration of maintenance of anaesthesia, total duration of anaesthesia, recovery time and quality parameters, viz., quality of sedation, induction, maintenance anaesthesia and recovery were recorded. There was significant reduction in the induction dose of etomidate as well as recovery time as compared to propofol with both the pre-anaesthetic agents. The induction dose of propofol was also significantly reduced particularly with butorphanol than with buprenorphine. Duration of surgery, duration of maintenance of anaesthesia and total duration of anaesthesia were apparently lower in group IV than other three groups, but the duration of surgery only differed significantly due to variety of surgical procedures. Quality of sedation, induction, maintenance anaesthesia and recovery were found good to excellent in all the groups.

Effect of intravenous lidocaine on the ED50 of propofol for inserting gastroscope without body movement in adult patients: a randomized, controlled study

BackgroundCirculatory and respiratory depression are common problems that occur in propofol alone sedation during gastroscopy. As a widely used analgesic adjuvant, intravenous lidocaine can reduce the consumption of propofol during Endoscopic retrograde cholangiopancreatography (ERCP) or colonoscopy. However, it is still unknown the median effective dose (ED50) of propofol when combined with lidocaine intravenously. This study aimed to compare the ED50 of propofol with or without intravenous lidocaine for inserting gastrointestinal endoscope successfully.MethodsFifty nine patients undergoing gastroscopy or gastrointestinal (GI) endoscopy were randomly divided into control group (Group C, normal saline + propofol) or lidocaine group (Group L, lidocaine + propofol). Patients were initially injected a bolus of 1.5 mg/kg lidocaine in Group L, whereas equivalent volume of 0.9% saline in Group C. Anaesthesia was then induced with a single bolus of propofol in all subjects. The induction dose of propofol was determined by the modified Dixon’s up-and-down method, and the initial dose was 1.5 mg/kg in both groups. The primary outcome was the ED50 of propofol induction dose with or without intravenous lidocaine. The secondary outcomes were the induction time, the first propofol bolus time (FPBT: from MOAA/S score ≤ 1 to first rescue bolus propofol), and adverse events (AEs: hypoxemia, bradycardia, hypotension, and body movements).ResultsTotally, 59 patients were enrolled and completed this study. The ED50 of propofol combined with lidocaine was 1.68 ± 0.11 mg/kg, significantly reduced compared with the normal saline group, 1.88 ± 0.13 mg/kg (P = 0.002). There was no statistical difference in induction time (P = 0.115) and the FPBT (P = 0.655) between the two groups. There was no significantly difference about the AEs between the two groups.ConclusionThe ED50 of propofol combined with intravenous lidocaine for successful endoscope insertion in adult patients, was 1.68 ± 0.11 mg/kg significantly reduced compared with the control group.Trial registrationChinese Clinical Trial Registry, No: ChiCTR2200059450. Registered on 29 April 2022. Prospective registration. http://www.chictr.org.cn.

Heart rate, arterial pressure and propofol-sparing effects of guaifenesin in dogs

ObjectiveTo evaluate the heart rate (HR) and systemic arterial pressure (sAP) effects, and propofol induction dose requirements in healthy dogs administered propofol with or without guaifenesin for the induction of anesthesia. Study designProspective blinded crossover experimental study. AnimalsA total of 10 healthy adult female Beagle dogs. MethodsDogs were premedicated with intravenous (IV) butorphanol (0.4 mg kg–1) and administered guaifenesin 5% at 50 mg kg–1 (treatment G50), 100 mg kg–1 (treatment G100) or saline (treatment saline) IV prior to anesthetic induction with propofol. HR, invasive sAP and respiratory rate (fR) were recorded after butorphanol administration, after guaifenesin administration and after propofol and endotracheal intubation. Propofol doses for intubation were recorded. Repeated measures analysis of variance (anova) was used to determine differences in propofol dose requirements among treatments, and differences in cardiopulmonary values over time and among treatments with p < 0.05 considered statistically significant. ResultsPropofol doses (mean ± standard deviation) for treatments saline, G50 and G100 were 3.3 ± 1.0, 2.7 ± 0.7 and 2.1 ± 0.8 mg kg–1, respectively. Propofol administered was significantly lower in treatment G100 than in treatment saline (p = 0.04). In treatments G50 and G100, HR increased following induction of anesthesia and intubation compared with baseline measurements. HR was higher in treatment G100 than in treatments G50 and saline following induction of anesthesia. In all treatments, sAP decreased following intubation compared with baseline values. There were no significant differences in sAP among treatments. fR was lower following intubation than baseline and post co-induction values and did not differ significantly among treatments. Conclusions and clinical relevanceWhen administered as a co-induction agent in dogs, guaifenesin reduced propofol requirements for tracheal intubation. HR increased and sAP and fR decreased, but mean values remained clinically acceptable.

Effect of anaesthetic maintenance with isoflurane or propofol on ease of endoscopic duodenal intubation in dogs

ObjectiveTo compare the ease of endoscopic duodenal intubation (EDI) in dogs during maintenance of general anaesthesia with isoflurane or propofol infusion. Study designProspective, randomized, partially blinded clinical trial. AnimalsA total of 22 dogs undergoing upper gastrointestinal tract endoscopy to include EDI were recruited. MethodsDogs were randomly assigned isoflurane (ISO; n = 10) or propofol (PROP; n = 11) for maintenance of general anaesthesia. Following anaesthetic premedication with intramuscular medetomidine (0.005 mg kg–1) and butorphanol (0.2 mg kg–1), general anaesthesia was induced with propofol, to effect, maintained with 1.5% (vaporizer setting) isoflurane in 100% oxygen or 0.2 mg kg–1 minute–1 propofol. The dose of both agents was adjusted to maintain general anaesthesia adequate for the procedure. Degree of sedation 20 minutes post-anaesthetic premedication, propofol induction dose, anaesthetist and endoscopist training grade, animal’s response to endoscopy, presence of gastro-oesophageal and duodenal-gastric reflux, spontaneous opening of the lower oesophageal and pyloric sphincters, antral movement and time to achieve EDI were recorded. EDI was scored 1 (immediate entry with minimal manoeuvring) to 4 (no entry after 120 seconds) by the endoscopist, blinded to the agent in use. Data were tested for normality (Shapiro-Wilk test) and differences between groups analysed using independent t test, Mann-Whitney U test and Fisher’s exact test as appropriate. ResultsThere were no significant differences between groups for EDI score [median (interquartile range): 2 (3) ISO, 2 (3) PROP] or time to achieve EDI [mean ± standard deviation: 52.50 ± 107.00 seconds (ISO), 70.00 ± 196.00 seconds (PROP)]. Significantly more dogs responded to passage of the endoscope into the oesophagus in group PROP compared with group ISO (p = 0.01). Conclusions and clinical relevanceMaintenance of general anaesthesia with either isoflurane or propofol did not affect EDI score or time to achieve EDI.

Effect of oral clonidine and tizanidine on the induction dose of propofol and intubation response in general anesthesia

Background: Laryngoscopy and tracheal intubation are associated with hemodynamic and cardiovascular responses consisting of increased heart rate, blood pressure and tachycardia and dysarrhythmias. The alpha2-adrenoreceptor agonists such as clonidine and tizanidine have several beneficial actions during the perioperative period. They improve hemodynamic stability in response to endotracheal intubation and surgical stress. Objective: To study the effect of oral clonidine and tizanidine on induction dose of propofol and hemodynamic responses after laryngoscopy in patients undergoing surgery under general anesthesia Methods: Hundred patients in age group of 18-70 years old of ASA 1/2 undergoing elective surgeries under general anesthesia with tracheal intubation was included in the study. Tizanidine 4 mg prescribed to group A, 0.1 mg clonidine to group B 60 min before the time of induction or laryngoscopy. systolic blood pressure, diastolic blood pressure, mean arterial blood pressure and heart rate recorded before induction, pre-intubation, after intubation at 0 min, and then at interval of 1,3,5 minute after laryngoscopy by an independent observer.

Effects of pre-medication with acepromazine/midazolam/ dexmedetomidine and butorphanol on induction dose of propofol and incidence of apnoea during induction in canines

The objective of the study was to evaluate the effect of ACE, MID, DEX (IM) and DEX (IV) with butorphanol on quality of induction, induction dose of propofol and incidence of apnoea during anaesthesia in client-owned dogs. Animals were randomly divided into four groups. After pre-medication with atropine sulphate, animals were administered with ACE @ 0.05 mg/kg b.wt IV in group A, MID @ 0.5 mg/kg IV b.wt in group B, DEX @ 15 μg/kg IM b.wt in group C and DEX @ 15 μg/kg IV b.wt in group D along with butorphanol @ 0.2 mg/kg b. wt. I/V. All animals were induced with propofol and maintained with isoflurane till the end of closing last skin suture. Adequate sedation and depth of analgesia was observed in the animals of the all four group and this sedation made handling of the animals proper and safe before induction. Significantly lower dose of propofol was needed for induction in the grous C and D as compared to groups A and B. Incidence of temporary apnoea in groups A and B was 10%, whereas in groups C and D was 30%, but they were managed by assisted ventilation and smoothly maintained with isoflurane without complication. It was found that ACE/MID/DEX with butorphanol has dose-sparing effect and provides adequate sedation and analgesia in the canines. Chances of apnoea may be more with DEX pre-medication, but they can be managed by assisted ventilation without any complication.

Utilization of submandibular ultrasound in assessing upper airway changes following the administration of propofol.

Our study aimed to use submandibular ultrasound to measure upper airway parameters before and after induction dose of propofol in order to further understand upper airway changes that occur during induction of anesthesia. Measuring the changes that occur in airway anatomy due to the hypotonic effects of induction agents will allow for a deeper understanding of airway management. We enrolled 39 patients between November 2021 and January 2022. Submandibular ultrasound was used to measure tongue thickness, geniohyoid muscle thickness, the distance between the lingual arteries (DLA), lateral pharyngeal wall thickness, and hyomental distance before and after administration of induction doses of the commonly used, sedative-hypnotic agent, propofol. The mean DLA increased significantly after propofol administration, from 3.62 ± 0.63 cm to 3.79 ± 0.56 cm (P < 0.001). The mean tongue thickness was 4.89 ± 0.51 cm and decreased significantly to a mean of 4.62 ± 0.50 cm after propofol administration (P < 0.001). The change in DLA measurements after propofol administration decreased significantly as STOP-BANG score increased (r = -0.344, P = 0.037). However, DLA measurements when patients were awake increased significantly with an increase in the STOP-BANG score (r = 0.351, P = 0.031). These findings suggest that propofol widens and flattens the tongue, which are changes that may contribute to difficult airway management. Given the quick and non-invasive nature of ultrasound, further studies should evaluate the role of submandibular ultrasound for understanding the upper airway and airway management in various populations.