Effect of low-dose ketamine versus fentanyl on attenuating the haemodynamic response to laryngoscopy and endotracheal intubation in patients undergoing general anaesthesia: a prospective, double-blinded, randomised controlled trial

Background: The use of drugs to attenuate the haemodynamic response to laryngoscopy and endotracheal intubation is the standard of care during elective surgery. Current evidence is conflicting concerning the best agent and optimal dose for this purpose. In the majority of cases, fentanyl is widely utilized to attenuate haemodynamic responses. Ketamine, an established available drug, has been scarcely studied in this regard at low doses and against varying doses of other common agents. Objective: To compare the overall occurrence of hypertension and tachycardia immediately pre-intubation (post-induction) until 10 minutes post intubation between the study group receiving fentanyl at 1.0 µg/kg and the other receiving ketamine at 0.5 mg/kg, to compare the occurrence of post-induction hypotension and the occurrence of neuropsychiatric phenomena during emergence between the two groups. Methods: One hundred and eight ASA I and II patients aged 18-65 years scheduled for elective surgery under general anaesthesia were randomized into two groups: Control group: received fentanyl 1.0 µg/kg intravenously. Intervention group: received ketamine 0.5 mg/kg intravenously. General anaesthesia was standardized in both groups. The patients and physicians administering anaesthesia were blinded to the study. Haemodynamic responses were evaluated by determining heart rate and blood pressure immediately before laryngoscopy and at 2.5, 5, 7.5 and 10 minutes. Neuropsychiatric phenomena were assessed upon recovery from anaesthesia. Results: One hundred and eight ASA I and II patients scheduled to undergo elective surgery were included in this study, 54 participants (50%) in the fentanyl arm and 54 (50%) in the ketamine arm. Baseline demographic characteristics were similar between the groups. There were more hypertensive episodes in the ketamine arm (11%) compared to the fentanyl arm (1.85%), but not achieving statistical significance: Fisher’s exact test, p=0.06. There was no significant difference in the number of episodes of tachycardia between the Ketamine group 7/54 (13%) and the fentanyl group, 6/54 (11%); x2=0.05, p=0.82. Hypotensive episodes were more common in those who received Fentanyl, 41/54 (76%), compared to ketamine recipients, 21/54 (39%), X2=16.9, p\u3c0.001. The use of Ketamine was associated with less episodes of hypotension, adjusted odds ratio = 0.18 (95% confidence interval 0.07, 0.45). Conclusion: We conclude, based upon findings in this study group, that there is no difference in the occurrence of hypertension with the use ketamine at 0.5 mg/kg in combination with Propofol at 2.0 mg/kg. In this regard, ketamine provides a viable alternative to fentanyl at 1.0 µg/kg for attenuating the pressor response to laryngoscopy and endotracheal intubation. Additionally, our results suggest that ketamine may protect against post-induction (pre-laryngoscopy) hypotension

Sensitivity of a preanaesthesia screening and triage tool in identifying high-risk patients attending the preanaesthesia assessment clinic in a tertiary referral hospital in Sub-Saharan Africa: a diagnostic accuracy study

Objectives: The use of preoperative triage questionnaires is an innovative way to mitigate the shortage of anaesthesiologists and to identify and refer high-risk patients early for evaluation. This study evaluates the diagnostic accuracy of one such questionnaire in identifying high-risk patients in a Sub-Saharan population. Design: Diagnostic accuracy study Setting: The study was conducted in a preanaesthesia assessment clinic in a tertiary referral hospital in SubSaharan Africa. Participants The study had a sample size of 128, including all patients above the age of 18 scheduled for elective surgery under any modality of anaesthesia other than local anaesthesia presenting to the preanaesthesia clinic. Patients scheduled for cardiac and major noncardiac surgery and those non-literate in English were excluded. Outcome measures: The sensitivity of the preanaesthesia risk assessment tool (PRAT) was the primary outcome measure. Other outcome measures were specificity, positive predictive value and negative predictive value. Results: Majority of patients were young and women with a mean age of 36 referred for obstetric and gynaecological procedures. The sensitivity of the PRAT in identifying highrisk patients was at 90.6% with 95%CI (76.9 to 98.2) in this current study while the specificity, negative predictive value (NPV) and positive predictive value (PPV) were 37.5% with 95%CI (24.0 to 43.7), 92.3% with 95%CI (77.7 to 97.0) and 32.6% with 95%CI (29.6 to 37.3) respectively. Conclusion: The PRAT has a high sensitivity and may be used as a screening tool in identifying high risk patients to refer to the anaesthesiologist early before surgery. Adjusting the high risk criteria to fit the anaesthesiologists’ assessments may improve the specificity of the tool

The Effect of Saline Flush After Rocuronium Bolus on Intubating Conditions in Adult Patients Undergoing Elective Surgery: A Randomized Controlled Trial

Background: In emergency surgeries requiring endotracheal intubation, the time to effect of neuromuscular blocking drugs is a crucial time to avoid hypoxia and aspiration into the lungs. Various strategies have been undertaken to shorten this time. All these methods have positive results but some are associated with side effects. The effectiveness of a muscle relaxant can either be assessed using the train of four or intubating conditions on the Goldberg scale. In this study, we investigated the effects of a 20 ml saline bolus following intravenous rocuronium at 0.6 mg/kg on the proportions of patients with excellent intubating conditions at one minute. Methodology: Fifty-two patients were randomly allocated to the saline bolus group or the no saline flush group. Anaesthesia was induced using propofol and remifentanil via target-controlled infusion (TCI) and maintained with the same. Rocuronium 0.6 mg/kg intravenous (IV) was administered followed by a 20 ml saline flush in the study group compared to administration of 0.6 mg/kg rocuronium without a saline bolus in the control group. Intubation conditions were assessed using the Goldberg scale filled by the intubating doctor. The onset of neuromuscular block was assessed by the train of four T1 height depression with an accelerometer attached to the adductor pollicis muscle. Results: There were 25 patients in each group. Patients in both groups were comparable with respect to demographic profiles. In the group with a flush, 18 (62.1%) patients had “excellent” and seven (33.3%) patients had “good” intubating conditions as opposed to 11 (37.9%) having “excellent” and 14 (66.7%) having “good” intubating condition in the group without a flush. The distribution of intubating conditions for the two groups showed a difference of 24.2% in the proportion of patients with excellent intubating conditions which was statistically significant (P=0.042). There was no association between twitch height at one minute and intubating conditions. Conclusion: In this group of patients studied, the administration of a 20 ml saline flush after 0.6mg/kg rocuronium significantly increases the proportion of patients with excellent intubating conditions as compared to rocuronium without a saline flush