The key role of pulse wave transit time to predict blood pressure variation during anaesthesia induction

Objective To establish the relationship between pulse wave transit time (PWTT) before anaesthesia induction and blood pressure variability (BPV) during anaesthesia induction. Methods This prospective observational cohort study enrolled consecutive patients that underwent elective surgery. Invasive arterial pressure, electrocardiography, pulse oximetry, heart rate and bispectral index were monitored. PWTT and BPV were measured with special software. Anaesthesia was induced with propofol, sufentanil and rocuronium. Results A total of 54 patients were included in this study. There was no correlation between BPV and the dose of propofol, sufentanil and rocuronium during anaesthesia induction. Bivariate linear regression analysis demonstrated that PWTT ( r = –0.54), age ( r = 0.34) and systolic blood pressure ( r = 0.31) significantly correlated with systolic blood pressure variability (SBPV). Only PWTT ( r = –0.38) was significantly correlated with diastolic blood pressure variability (DBPV). Patients were stratified into high PWTT and low PWTT groups according to the mean PWTT value (96.8 ± 17.2 ms). Compared with the high PWTT group, the SBPV of the low PWTT group increased significantly by 3.4%. The DBPV of the low PWTT group increased significantly by 2.1% compared with the high PWTT group. Conclusions PWTT, assessed before anaesthesia induction, may be an effective predictor of haemodynamic fluctuations during anaesthesia induction.

Evaluation of blood electrolyte alterations in cats during elec-tive laparoscopic ovariectomy

In a clinical setting, we tested the hypothesis of whether hypercapnia developed during carbon dioxide pneumoperitoneum is associated with changes in blood electrolytes. This prospective study involved ten female cats that underwent elective laparoscopic ovariectomy. Venous blood samples for assessment of electrolytes were collected in the following sequence: T1- before anaesthesia induction, T2 - 10 minutes after anaesthesia induction, T3 - 30 minutes of pneumoperitoneum and T4 - at the end of pneumoperitoneum. Statistical analysis revealed AB disturbances associated with general anaesthesia and pneumoperitoneum, manifested with decreased blood pH, whereas blood PvCO2, PO2 and BE were increased. A constant increase of K+ concentration was recorded in all animals during pneumoperitoneum (P<0.05), whereas iMg registered a significant increase only at T3 (P<0.05). Correlations were recorded between blood pH and Na+, iCa, iMg, as well as between Na+ and Cl¯ at different time points during anaesthesia. No correlations were noted between pH and K+ or PvCO2 and K+. In conclusion, electrolyte imbalance represents a possible complication associated with laparoscopic surgery in healthy cats. However, further studies should investigate the causes involved in K+ concentration elevation.

Comparison of Recovery Quality Following Medetomidine versus Xylazine Balanced Isoflurane Anaesthesia in Horses: A Retrospective Analysis

Medetomidine partial intravenous anaesthesia (PIVA) has not been compared to xylazine PIVA regarding quality of recovery. This clinical retrospective study compared recoveries following isoflurane anaesthesia balanced with medetomidine or xylazine. The following standard protocol was used: sedation with 7 µg·kg−1 medetomidine or 1.1 mg·kg−1 xylazine, anaesthesia induction with ketamine/diazepam, maintenance with isoflurane and 3.5 µg·kg−1·h−1 medetomidine or 0.7 mg·kg−1·h−1 xylazine, and sedation after anaesthesia with 2 µg·kg−1 medetomidine or 0.3 mg·kg−1 xylazine. Recovery was timed and, using video recordings, numerically scored by two blinded observers. Influence of demographics, procedure, peri-anaesthetic drugs, and intraoperative complications (hypotension, hypoxemia, and tachycardia) on recovery were analysed using regression analysis (p < 0.05). A total of 470 recoveries (medetomidine 279, xylazine 191) were finally included. Following medetomidine, recoveries were significantly longer (median (interquartile range): 57 (43–71) min) than xylazine (43 (32–59) min) (p < 0.001). However, the number of attempts to stand was similar (medetomidine and xylazine: 2 (1–3)). Poorer scores were seen with increased pre-anaesthetic dose of xylazine, intraoperative tetrastarch, or salbutamol. However, use of medetomidine or xylazine did not influence recovery score, concluding that, following medetomidine–isoflurane PIVA, recovery is longer, but of similar quality compared to xylazine.

Preoperative rigid laryngoscopic examination and modified jaw thrust manoeuver during fibreoptic-assisted tracheal intubation for general anaesthesia

Preoperative laryngoscopic examination of the airway informs general anaesthesia management and planning. However, the same glottic opening view cannot always be obtained during direct laryngoscopy of anaesthetised patients. In this case report, a patient underwent preoperative rigid laryngoscopy due to medical history, and no problems were anticipated in performing tracheal intubation; however, the direct laryngoscopic view was a Grade 4 on the Cormack-Lehane Scale after anaesthesia induction. A jaw thrust manoeuvre to facilitate fibreoptic-assisted nasotracheal intubation was not feasible. In order to compensate, a modified method of jaw thrust was implemented, where both thumbs were placed on the floor of the patient’s mouth, leading to a successful result. Safe airway management should be implemented with proper planning based on a careful preoperative evaluation.

Effectiveness of preoperative tour to a simulated anaesthesia induction at operating theatre in reducing preoperative anxiety in children and their parents: a pragmatic, single-blinded, randomised controlled trial/ King Fahad Medical City

ObjectiveTo evaluate the effectiveness of a preoperative tour to a simulated anaesthesia induction at operating theatre on reducing children’s and parents’ preoperative anxiety.DesignA pragmatic, single-centre, assessor-blinded, randomised controlled trial.SettingIn preoperative anaesthesia clinic and the operating room at a tertiary care centre in Saudi Arabia.ParticipantsOne hundred and sixteen children–parents dyads (pairs) (n=57) intervention group (IG); (n=59) control group (CG) with children aged 4–14 years who were planned for day case procedures under general anaesthesia.InterventionsParticipants’ dyads were randomly allocated through a computer to receive either a preoperative tour to a real operating theatre and simulate anaesthesia induction or standard of care.Main outcome measureThe primary study outcome was children’s anxiety levels as measured by the modified-Yale Preoperative Anxiety Scale (m-YPAS), and the parent’s anxiety level as assessed by the Beck Anxiety Inventory Scale. The children’s anxiety levels were measured at two time points, the preoperative holding area (T0) and before the anaesthesia induction (T1), and the parents’ anxiety level was measured after the anaesthesia induction. The secondary outcomes were the prevalence of preoperative anxiety and children’s somatic signs of anxiety including heart rate and systolic blood pressure.ResultsThe Mann-Whitney U test of m-YPAS scores showed significant differences in the children’s anxiety levels between the CG and IG at T0 (Z −5.009); p<0.01) and T1 (Z −6.599); p<0.01). BIAS analysis revealed a significant difference in the parents’ anxiety level between the CG and IG (Z −4.353); p<0.01). The prevalence of children’s anxiety was reported by 55 (93.2%) in the CG compared with 25 (43.9%) in the IG, with a statistically significant difference (p<0.001).ConclusionThe preoperative simulated anaesthesia induction was effective in reducing preoperative anxiety in children and their parents.

Comparison of Use of Isoflurane or Sevoflurane for Anaesthesia Induced by Mask in Calves

Background: Inhalation anaesthesia is an effective and reliable general anaesthesia method for inactivity, analgesia, and unconsciousness in extensive surgical procedures. Although widely used, especially in small animals, there are very few studies investigated the reliability and superiority of inhalation anaesthesia in surgical procedures for ruminants. This study intended to evaluate the anaesthetic effects of isoflurane and sevoflurane in different surgical cases with endotracheal intubation following the induction of anaesthesia using a calve-specific facemask, which is not yet a routine option in cattle.Materials, Methods & Results: The study was conducted on 14 calves, from new-born up to 3 months-old, that undergoing various surgical operations. The animals were divided into isoflurane and sevoflurane groups, and each group contained 7 animals. In all cases, atropine (0.04 mg/kg was administered intramusculer as premedication before 15 min from anaesthesia induction. For induction, the anaesthetic agent was given at an inspiratory concentration of 3-5% in the isoflurane group and at an inspiratory concentration of 5 - 7% in the sevoflurane group during 5 min via mask at 15min after atropine administration. In both groups, endotracheal intubation was performed (about 1-3 min) after of general anaesthesia symptoms starting. At 5min after induction, anaesthesia was continued at 1.5 - 3% in the isoflurane group and at 2.5 - 4% in the sevoflurane group during operation. The animals were monitored during anaesthesia and, anaesthetic effect, reaction of the calve, pronounced side effects, Heart Rate (HR), Systolic Arterial Blood Pressure (SABP), Diastolic Arterial Blood Pressure (DABP), Mean Arterial Blood Pressure (MABP), Respiration Rate (RR), Pulse Rate (PR), Arterial Oxygen Saturation (SpO2) were recorded at before anaesthesia, the premedication period, 5, 15, 30, 45, 60, 75 and 90min of anaesthesia. During anaesthesia, from the clinical parameters, mucosal capillary refilling time was evaluated by applying finger pressure to the oral mucosa. Mucous membrane color was determined by observing the oral mucosa. The time for palpebral reflex and swallowing reflex disappearance was measured and processed into individual forms. Anaesthesia induction and reanimation times were determined and recorded in the forms. After the operation, the return of the swallowing reflex and the time to stand up were recorded. During the operation, urination, defecation, salivation, vomiting, animal reactions, the shape and duration of the reamination period were recorded. In the isoflurane group anaesthesia induction was 3.71 ± 0.28 min, head movements started and came to the sterno- abdominal position at 4.57 ± 0.36 min, got up at 8.71 ± 0.42 min without assistance, meanwhile. In sevoflurane group, anaesthesia induction was 2.57 ± 0.20 min, head movements started and came to the sterno- abdominal position at 3.86 ± 0.40 min, the time to stand up was determined as 6.43 ± 0.29 min. During anaesthesia, HR, SABP, DABP, MABP, RR, PR, SpO2 findings were within physiological acceptable limits in 2 groups. In terms of indicators, there were no obvious differences in either group. The results revealed no significant difference between groups during anaesthesia.Discussion: The isoflurane and sevoflurane anaesthesia used in this study provided an adequate anaesthetic effect in calves characterized by adequate analgesia and muscle relaxation without any complications. The results of our study revealed that there was no significant difference between isoflurane and sevoflurane in calves. Both anaesthetic agents can be used safely for general anaesthesia in calves.

Prolonged Intraoperative Cardiac Arrest in a Young Patient with Successful Precordial Thump

Cardiac arrest during surgery is rare but is one of the most dreaded complications. Precordial thump (PT) had been used for a long time, but in the present day it has become obsolete. In regard to the witnessed onset of asystole, there is insufficient evidence to recommend for or against the use of the PT. This case report is of a 17-year-old male who presented to hospital with a congenital haemangioma on the right calf. He had no other significant medical conditions and was on no other medications. The patient history, clinical examination, and investigations were normal. He had undergone an operation 3 weeks previously where a section of his haemangioma was excised, and an appointment was made for excision of the remaining haemangioma. Anaesthesia induction and endotracheal intubation were smooth and uneventful. Following lifting and exsanguination of the patient’s leg by Esmarch bandage, he developed ventricular fibrillation and arrested with asystole. Cardiopulmonary resuscitation was performed, with no good response, for approximately 50 minutes. Lastly, a PT was performed, and the patient’s heart rate immediately returned. The operation was postponed. Postresuscitation care was conducted in an intensive care unit. The patient was later discharged without complications.