Ketamine For Induction Of Anaesthesia Research Articles

Effects of brotizolam as a co-agent with ketamine for induction of anaesthesia in calves

Anaesthesia in food producing animals in the EU and UK is legally limited to a narrow choice of drugs; the only licensed benzodiazepine being brotizolam. The aim of this study was to investigate the effects of brotizolam as a co-agent with ketamine on the quality of induction, intubation, muscle relaxation and recovery from isoflurane anaesthesia. Seventeen calves were enrolled in this prospective, blinded, randomized experimental study. Calves were sedated with 0.05 mg/kg xylazine and 0.1 mg/kg butorphanol IV. After assessing the quality of sedation, anaesthesia was induced with 2 mg/kg ketamine (group KETA) or 2 mg/kg ketamine with 2 μg/kg brotizolam IV (group BROTI). An additional 1 mg/kg ketamine was administered IV every 2 min until intubation was possible. Anaesthesia was maintained with isoflurane in a mixture of oxygen and air. The amount of ketamine required, quality of induction, intubation, muscle relaxation, and recovery were scored and compared between groups using ordinal regression models (P < 0.05 was considered statistically significant).Sedation scores did not differ significantly between groups but were positively associated with the quality of recovery (P = 0.0098). Group BROTI was associated with a lower quality of induction (P < 0.0001), intubation (P = 0.0203) and muscle relaxation (P = 0.0043). The sedation score and treatment had no effect on the number of attempts of intubation, additional ketamine doses, time to extubation and recovery time. Brotizolam had a negative effect on the quality of induction, intubation, and muscle relaxation compared to ketamine alone. We do not recommend using brotizolam under these circumstances.

Effects of Brotizolam as a Co-Agent with Ketamine for Induction of Anaesthesia in Calves

Effects of Brotizolam as a Co-Agent with Ketamine for Induction of Anaesthesia in Calves

Thiopental versus ketamine for induction of anesthesia in septic shock: a randomized controlled trial

Background Induction of anesthesia in patients with septic shock might result in deleterious hypotension. The aim of this work is to compare low-dose thiopental versus ketamine for induction of anesthesia in patients with septic shock. Patients and methods In this randomized controlled double-blinded trial, we included 26 patients with septic shock scheduled for emergency operations under general anesthesia. According to the induction protocol, patients were divided into thiopental group (received thiopental 2 mg/kg+fentanyl 0.5 μg/kg+midazolam 0.05 mg/kg), and ketamine group (received ketamine 1 mg/kg+fentanyl 0.5 μg/kg+midazolam 0.05 mg/kg). Both groups were compared according to mean arterial pressure, cardiac output, heart rate, vasopressor requirements, and incidence of postinduction hypotension. Results Both groups were comparable in demographic data. No significant differences were reported between both groups based on mean arterial pressure, cardiac output, and heart rate; however, ketamine group showed higher incidence of postinduction hypotension [11/13 (85%) vs. 5/13 (39%) patients, P=0.041] compared with thiopental group. Conclusion Both study regimens, thiopental-based regimen and ketamine-based regimen, showed equivalent hemodynamic effects when used for induction of anesthesia in patients with septic shock. However, thiopental-based regimen was less likely associated with postinduction hypotension.

Comparison of two doses of ketamine for induction of anaesthesia in ponies undergoing field castration.

Background:Ketamine-based total intravenous anaesthesia techniques are commonly used in equine practice for ponies requiring short procedures such as castration in field conditions. When a longer duration of recumbency than provided by the initial dose of anaesthetic agents is required, administration of supplementary ‘top-up’ doses of anaesthetic agents is required. Ideally, a single dose of anaesthetic agents would reliably achieve a longer duration of action whilst maintaining adequate anaesthetic, surgical and recovery qualities.Aim:This prospective, randomised and blinded study aimed to compare the UK-licensed induction dose of ketamine with an increased dose in ponies undergoing castration in field conditions. The hypothesis was that an increased dose would produce a longer duration of action without negatively affecting qualities of anaesthesia, surgical conditions and recovery.Methods:Ponies were randomly allocated to receive ketamine at either 2.2 mg kg-1 (K2.2) or 3 mg kg-1 (K3) combined with diazepam 20 μg kg-1 following pre-anaesthetic medication with romifidine and butorphanol. Quality of anaesthesia, surgery and recovery were scored using simple descriptive scales (SDS) and timings of key events recorded. Top-up doses of ketamine 0.5 mg kg-1 were administered if anaesthesia was inadequate during surgery. Time of top-up doses and total ketamine doses were recorded. Data were analysed using Student t-tests or the Mann-Whitney U test (p < 0.05).Results:Thirty-six ponies completed the study. Six ponies enrolled were excluded due to cryptorchidism or surgical complications that required deviation from the anaesthetic protocol. There were no differences in timing of events recorded, number of ponies requiring top-up ketamine, timing and frequency of top-ups or total ketamine dose. Scores for anaesthetic and recovery qualities, and surgical conditions were similar between groups.Conclusion:Both induction doses of ketamine provided a similar duration of action and provided conditions suitable to anaesthetise ponies undergoing castration.

Comparison of xylazine and detomidine in combination with midazolam/ketamine for field castration in Quarter Horses.

The ideal field anaesthetic protocol for castration will offer an adequate duration and depth of anaesthesia using a single injection without compromising safety or recovery quality. The objective of this study was to compare intravenous (IV) xylazine and detomidine as sedatives in combination with midazolam and ketamine for induction of anaesthesia in horses undergoing field castration. Randomised, blinded, clinical study. Fifty-seven male Quarter Horses were randomly assigned to receive xylazine (group X) (1.1mg/kg bwt) or detomidine (group D) (0.03mg/kg bwt) as premedication with midazolam (0.05mg/kg bwt) and ketamine (2.2mg/kg bwt) anaesthesia. Using simple descriptive scales, quality of sedation, induction, surgical conditions and recovery were scored by blinded observers. Induction, surgery, recovery time and time from induction to standing were recorded. There were a greater number of horses with lower sedation score in group D when compared with horses in group X at 5minutes after the first dose of sedation (11.1%, 66.7% and 2.2% of horses from group D with sedation scores of 1, 2 and 3, vs 0%, 52% and 48% from group X, respectively, P=.05). A significant (P<.01) difference was found between surgical condition scores for group D (63%, 14.8%, 11.1% and 11.1% with surgery scores of 1, 2, 3 and 4, respectively) and group X (28%, 4%, 28% and 40%). Horses in Group D were less likely to require maintenance doses of ketamine (P=.05) with only 26% (7 of 27 horses) in this group requiring additional doses compared to 68% (17 of 25 horses) in group X. Recovery time in minutes (Group D: 24.74±14.80, Group X: 13.08±8.00; P<.01) and induction to standing time in minutes (Group D: 42.2±13.8, Group X: 29.8±8.2; P<.01) were significantly longer for horses in group D compared with group X. Multiple surgeons and multiple blinded observers. Detomidine as compared with xylazine as premedication results in good quality sedation and surgical conditions and prolonged surgical plane of anaesthesia, without significant differences in induction or recovery quality.

Clinical evaluation of intranasal medetomidine–ketamine and medetomidine–S(+)-ketamine for induction of anaesthesia in rabbits in two centres with two different administration techniques

ObjectiveThe aim was to compare efficacy and side effects of induction with medetomidine–ketamine or medetomidine–S(+)-ketamine by intranasal (IN) instillation in rabbits and to evaluate both protocols during subsequent isoflurane anaesthesia. Study designProspective, blinded, randomized experimental study in two centres. AnimalsEighty-three healthy New Zealand White rabbits undergoing tibial or ulnar osteotomy. MethodsMedetomidine (0.2 mg kg−1) with 10 mg kg−1 ketamine (MK) or 5 mg kg−1 S(+)-ketamine (MS) was administered IN to each rabbit in a randomized fashion. In Centre 1 (n = 42) rabbits were held in sternal recumbency, and in Centre 2 (n = 41) in dorsal recumbency, during drug instillation. Adverse reactions were recorded. If a rabbit swallowed during endotracheal intubation, half of the initial IN dose was repeated and intubation was re-attempted after 5 minutes. Anaesthesia was maintained with isoflurane. Heart rate, blood pressure, endtidal carbon dioxide concentration and blood gases were recorded. Data were analysed using Student's t-test, Mann–Whitney test and Fisher's exact test. ResultsIn all, 39 animals were assigned to the MK group and 44 to the MS group. Two rabbits in the MS group held in dorsal recumbency died after instillation of the drug. Eight (MK) and 11 rabbits (MS) were insufficiently anaesthetized and received a second IN dose. One rabbit in MK and three in MS required an isoflurane mask induction after the second IN dose. There were no significant differences between treatments for induction, intraoperative data, blood gas values and recovery data. Conclusion and clinical relevanceThis study indicated that medetomidine–ketamine and medetomidine-S(+)-ketamine were effective shortly after IN delivery, but in dorsal recumbency IN administration of S(+)-ketamine led to two fatalities. Nasal haemorrhage was noted in both cases; however, the factors leading to death have not been fully elucidated.

Comparative study between propofol and propofol-ketamine for induction of anesthesia in dogs

Os procedimentos anestésicos em animais são amplamente utilizados em hospitais para cirurgias de rotina. Para a indução anestésica em cães o propofol tem se mostrado o fármaco de escolha. O objetivo deste estudo foi a avaliação da indução anestésica com propofol ou propofol-cetamina. Vinte cães foram divididos de forma aleatória nos grupos com tratamento e controle. Em todos os pacientes administrou-se acepromazina (0,05 mg kg-1) e fentanil (5 µg kg-1) como medicação pré-anestésica por via intramuscular (IM). Nos cães do grupo de tratamento foi administrado cetamina (1 mg kg-1), enquanto que os cães do grupo controle receberam solução salina a 0,9%, pela via intravenosa (IV). A indução da anestesia foi realizada com propofol IV a uma taxa de 1 mL minuto-1. Os padrões cardiopulmonares foram avaliados antes da aplicação da medicação pré-anestésica, 15 minutos após a mesma e após a indução da anestesia. Além disso, avaliou-se o escore de intubação traqueal, a presença de efeitos adversos e a dose de propofol necessária para a indução da anestesia. De forma significativa, o grupo controle apresentou mais efeitos adversos e alterações nos padrões cardiopulmonares quando comparado com o grupo de tratamento. Houve uma redução clinicamente importante da dose de propofol necessária para a indução de anestesia quando associado à cetamina. A associação de cetamina ao propofol para indução de anestesia em cães saudáveis foi capaz de reduzir a dose do anestésico geral necessária para intubação traqueal. Além disso, houve uma redução na ocorrência de efeitos adversos e depressão cardiopulmonar, o que permitiu um procedimento mais seguro para os pacientes.

Comparison of midazolam and diazepam as co-induction agents with ketamine for anaesthesia in sedated ponies undergoing field castration

ObjectiveTo compare intravenous (IV) midazolam and diazepam administered with ketamine for induction of anaesthesia in ponies, already sedated with detomidine, undergoing field castration. Study designProspective, randomised, ‘blinded’, clinical study. AnimalsTwenty Welsh pony yearlings. MethodsAfter IV injection of detomidine (20 μg kg−1) and phenylbutazone (4.4 mg kg−1) ponies were allocated to receive either IV midazolam (group M) or diazepam (group D) (both 0.06 mg kg−1) with ketamine (2.2 mg kg−1) for induction of anaesthesia. Using simple descriptive scales, quality of sedation, induction, endotracheal intubation, surgical conditions and recovery were scored by observers blinded to treatment. Time from sedation to induction of anaesthesia, IV injection to lateral recumbency, induction to start of surgery, induction to first head lift and to standing, and total surgical time were measured. Cardiorespiratory function was assessed every 5 minutes. Time, number and total quantity of additional IV ketamine as well as any adverse effects were documented. Data were tested for normality and analysed using two-way anova with Bonferroni post hoc tests, unpaired t-tests and Mann–Whitney U tests as appropriate. Significance was set at p < 0.05. ResultsThere were no significant group differences in any of the measured variables except bodyweight (mean ± SD: group M 163 ± 12 kg; group D 150 ± 7 kg; p = 0.01). One pony in group M required ketamine 15 minutes after induction of anaesthesia. Surgical conditions were good in all cases; time from induction to standing was 50 ± 11 minutes in group M and 48 ± 12 minutes in group D. There were no adverse effects. Recoveries were uneventful with minimal ataxia. Conclusions and clinical relevanceMidazolam and diazepam at 0.06 mg kg−1 can be used interchangeably in combination with ketamine for IV induction of short term anaesthesia in ponies.

Alfaxalone compared with ketamine for induction of anaesthesia in horses following xylazine and guaifenesin

ObjectiveTo compare anaesthesia induced with either alfaxalone or ketamine in horses following premedication with xylazine and guaifenesin. Study designRandomized blinded cross-over experimental study. AnimalsSix adult horses, five Standardbreds and one Thoroughbred; two mares and four geldings. MethodsEach horse received, on separate occasions, induction of anaesthesia with either ketamine 2.2 mg kg−1 or alfaxalone 1 mg kg−1. Premedication was with xylazine 0.5 mg kg−1 and guaifenesin 35 mg kg−1. Incidence of tremors/shaking after induction, recovery and ataxia on recovery were scored. Time to recovery was recorded. Partial pressure of arterial blood oxygen (PaO2) and carbon dioxide (PaO2), arterial blood pressures, heart rate (HR) and respiratory rates were recorded before premedication and at intervals during anaesthesia. Data were analyzed using Wilcoxon matched pairs signed rank test and are expressed as median (range). ResultsThere was no difference in the quality of recovery or in ataxia scores. Horses receiving alfaxalone exhibited a higher incidence of tremors/shaking on induction compared with those receiving ketamine (five and one of six horses respectively). Horses recovered to standing similarly [28 (24–47) minutes for alfaxalone; 22 (18–35) for ketamine] but took longer to recover adequately to return to the paddock after alfaxalone [44 (38–67) minutes] compared with ketamine [35 (30–47)]. There was no statistical difference between treatments in effect on HR, PaO2 or PaCO2 although for both regimens, PaO2 decreased with respect to before premedication values. There was no difference between treatments in effect on blood pressure. Conclusions and clinical relevanceBoth alfaxalone and ketamine were effective at inducing anaesthesia, although at induction there were more muscle tremors after alfaxalone. As there were no differences between treatments in relation to cardiopulmonary responses or quality of recovery, and only minor differences in recovery times, both agents appear suitable for this purpose following the premedication regimen used in this study.

Ketamine for rapid sequence induction in patients with head injury in the emergency department

To examine the evidence regarding the use of ketamine for induction of anaesthesia in patients with head injury in the ED. A literature review using the key words ketamine, head injury and intracranial pressure. Advice from early literature guiding against the use of ketamine in head injury has been met with widespread acceptance, as reflected by current practice. That evidence is conflicting and inconclusive in regards to the safety of using ketamine in head injury. A review of the literature to date suggests that ketamine could be a safe and useful addition to our available treatment modalities. The key to this argument rests on specific pharmacological properties of ketamine, and their effects on the cerebral haemodynamics and cellular physiology of brain tissue that has been exposed to traumatic injury. In the modern acute management of head-injured patients, ketamine might be a suitable agent for induction of anaesthesia, particularly in those patients with potential cardiovascular instability.

Lidocaine-Ketamine Versus Ketamine for Induction of Anesthesia in Septic Shock Patients

Lidocaine-Ketamine Versus Ketamine for Induction of Anesthesia in Septic Shock Patients

Ketamine in the field: the use of ketamine for induction of anaesthesia before intubation in injured patients in the field

Intubating the subconscious, struggling patient in a pre-hospital setting can be a difficult task even in experienced hands. We performed a clinical prospective study to evaluate the applicability of ketamine for induction of anaesthesia before intubation in the field. Ketamine was distributed to all air medical rescue teams--trained reserve army volunteers from various medical specialties. Lectures and literature concerning the use of ketamine for anaesthesia induction before intubation were given. The physicians were instructed to administer ketamine, in a dose of 2 mg/kg intravenously, if a single intubation attempt failed. Following the administration of ketamine, a questionnaire was filled in by the physician. Analysis of the data was performed after 24 months. During the study period, intubation was indicated in 161 injured patients evacuated by air in Israel. In 29 patients (18 per cent) the first intubation attempt had failed and they were given ketamine. The reasons for failure of the first intubation attempt were restlessness or trismus in 23 patients and traumatic distortion of the upper airway anatomical landmarks in six. Following ketamine administration, intubation was successful in 19 patients (65.5 per cent) in all of whom the indication for ketamine administration was restlessness or trismus. All patients with upper airway anatomy distortion were given a cricothyroidotomy. There were no complications attributed to ketamine. All patients reached hospital alive. This preliminary study suggests that the use of ketamine in this pre-hospital setting is safe. The drug is effective in cases where the primary reason for failure to intubate is restlessness or trismus. The drug is not effective in cases of anatomical damage to the upper airway. In these cases, cricothyroidotomy should probably be performed as early as possible.

Advantages and Guidelines for Using Ketamine for Induction of Anesthesia

Ketamine in combination with a sedative or tranquilizer is a relatively safe and effective drug for intravenous induction of anesthesia in dogs and cats. If properly dosed, the combination can be used to induce anesthesia with minimal adverse cardiovascular effects, and it is a reasonable method for induction of anesthesia in patients with cardiac disease. If dosage is kept low, the rate of recovery is acceptable, and some of the drugs commonly used in the regimen with ketamine are reversible with appropriate antagonists.

Precautions When Using Ketamine for Induction of Anesthesia

Precautions When Using Ketamine for Induction of Anesthesia

Rectal Ketamine for Induction of Anaesthesia in Children

Rectal Ketamine for Induction of Anaesthesia in Children

Rectal ketamine for induction of anaesthesia in children

Rectal premedication with atropine and diazepam and rectal induction of anaesthesia with ketamine have been used in 30 healthy children undergoing minor surgetv. The anticholinerigic and sedative effects of the premedication were satisfactory. Induction of anaesthesia was smooth with no adverse circulatory or respiratory effects. No psychotomimetic side-effects were seen, and analgesia persisted into the recovery period. Plasma concentrations of ketamine and norketamine were measured in eight childrer: and revealed a pharmacokinetic pattern indicating comparatively low bioavailability probably due to incomplete absorption from the rectum and a high ‘first-pass’ metabolism. The technique of rectal administration of ketamine needs further pharmacokinetic evaluation before it can be generally recommended.

Rectal ketamine for induction of anaesthesia in children.

Rectal premedication with atropine and diazepam and rectal induction of anaesthesia with ketamine have been used in 30 healthy children undergoing minor surgery. The anticholinergic and sedative effects of the premedication were satisfactory. Induction of anaesthesia was smooth with no adverse circulatory or respiratory effects. No psychotomimetic side-effects were seen, and analgesia persisted into the recovery period. Plasma concentrations of ketamine and norketamine were measured in eight children and revealed a pharmacokinetic pattern indicating comparatively low bioavailability probably due to incomplete absorption from the rectum and a high 'first-pass' metabolism. The technique of rectal administration of ketamine needs further pharmacokinetic evaluation before it can be generally recommended.