Ketamine hydrochloride

Comparison of different administration of ketamine and intravenous tramadol hydrochloride for postoperative pain relief and sedation after pediatric tonsillectomy.[Pubmed:25569408]

J Craniofac Surg. 2015 Jan;26(1):e21-4.

OBJECTIVES: Tonsillectomy is the oldest and most frequently performed surgical procedure practiced by ear, nose, and throat physicians. In this study, our aim was to compare the analgesic effects of peritonsillar, rectal, as well as intravenous infiltration of ketamine and intravenous tramadol hydrochloride infiltration for postoperative pain relief and sedation after tonsillectomy in children. MATERIALS AND METHODS: This randomized controlled study evaluated the effects of peritonsillar, intravenous, and rectal infiltration of ketamine in children undergoing adenotonsillectomy. One hundred twenty children who were categorized under American Society of Anesthesiologists classes I to II were randomized to 4 groups of 30 members each. Group 1 received intravenous (IV) ketamine (0.5 mg/kg), group 2 received rectal ketamine (0.5 mg/kg), group 3 received local peritonsillar ketamine (2 mg/kg), and the control group received IV tramadol hydrochloride infiltration (2 mg/kg). Children's Hospital of Eastern Ontario Pain Scale scores and Wilson sedation scale were recorded at minutes 1, 15, 30, 60 as well as hours 2, 12, and 24 postoperatively. The patients were interviewed on the day after the surgery to assess the postoperative pain and sedation. RESULTS: All the routes of infiltration of ketamine were as effective as those of tramadol hydrochloride (P > 0.05). A statistically significant difference was observed between IV infiltrations and all groups during the assessments at hours 6 and 24. The analgesic efficacy of IV ketamine was found especially higher at hours 6 and 24 (P(6) = 0.045, P(24) = 0.011). CONCLUSIONS: Perioperative, low-dose IV, rectal, or peritonsillar ketamine infiltration provides efficient pain relief without any adverse effects in children who would undergo adenotonsillectomy.

Effects of anesthetic induction with a benzodiazepine plus ketamine hydrochloride or propofol on hypothermia in dogs undergoing ovariohysterectomy.[Pubmed:27027833]

Am J Vet Res. 2016 Apr;77(4):351-7.

OBJECTIVE: To assess the effect of anesthetic induction with a benzodiazepine plus ketamine or propofol on hypothermia in dogs undergoing ovariohysterectomy without heat support. ANIMALS: 23 adult sexually intact female dogs undergoing ovariohysterectomy. PROCEDURES: Baseline rectal temperature, heart rate, and respiratory rate were recorded prior to premedication with buprenorphine (0.02 mg/kg, IM) and acepromazine (0.05 mg/kg, IM). Anesthesia was induced with midazolam or diazepam (0.25 mg/kg, IV) plus ketamine (5 mg/kg, IV; n = 11) or propofol (4 mg/kg, IV; 12) and maintained with isoflurane in oxygen. Rectal temperature was measured at hospital intake, prior to premedication, immediately after anesthetic induction, and every 5 minutes after anesthetic induction. Esophageal temperature was measured every 5 minutes during anesthesia, beginning 30 minutes after anesthetic induction. After anesthesia, dogs were covered with a warm-air blanket and rectal temperature was measured every 10 minutes until normothermia (37 degrees C) was achieved. RESULTS: Dogs in both treatment groups had lower rectal temperatures within 5 minutes after anesthetic induction and throughout anesthesia. Compared with dogs that received a benzodiazepine plus ketamine, dogs that received a benzodiazepine plus propofol had significantly lower rectal temperatures and the interval from discontinuation of anesthesia to achievement of normothermia was significantly longer. CONCLUSIONS AND CLINICAL RELEVANCE: Dogs in which anesthesia was induced with a benzodiazepine plus propofol or ketamine became hypothermic; the extent of hypothermia was more profound for the propofol combination. Dogs should be provided with adequate heat support after induction of anesthesia, particularly when a propofol-benzodiazepine combination is administered.

Long-term stability of ketamine hydrochloride 50mg/ml injection in 3ml syringes.[Pubmed:27107463]

Ann Pharm Fr. 2016 Jul;74(4):283-7.

INTRODUCTION: Ketamine hydrochloride (Ketalar((R))) injection is often used as a general anesthetic agent. It is particularly suited to short-term interventions. It can also be used as an inducer of anesthesia before the administration of other anesthetic agents. The aim of this study was to evaluate the stability of Ketamine hydrochloride in 3ml polypropylene syringes after storage for up to 180days at room temperature. METHOD: Syringes containing Ketamine hydrochloride (50mg/ml) were prepared and stored at room temperature (25 degrees C) for 180days. The concentrations were measured by validated ultra-performance liquid chromatography-diode array detection at 0, 7, 14, 28, 60, 84, 112, 140 and 180days. A degradation test was performed to evaluate the specificity of the analysis. At each time point, the pH, color and visible particles of each solution were also assessed. RESULTS: Degradation tests proved no interfering peaks with ketamine. All solutions were physically stable during the storage. The lower confidence limit of the concentration for these solutions remains superior to 90% of the initial concentration at this date as recommended by the Food and Drug Administration (FDA) until 180days (100%+/-2%). CONCLUSION: Solutions of ketamine (50mg/ml) were chemically stable for 180days in polypropylene syringes with storage at room temperature and could be prepared in advance by a centralized intravenous admixture service.

Effects of premedication with sustained-release buprenorphine hydrochloride and anesthetic induction with ketamine hydrochloride or propofol in combination with diazepam on intraocular pressure in healthy sheep.[Pubmed:26309105]

Am J Vet Res. 2015 Sep;76(9):771-9.

OBJECTIVE: To determine the effects of diazepam combined with Ketamine hydrochloride or propofol for induction of anesthesia (IOA) following premedication with sustained-release buprenorphine hydrochloride (SRB) on intraocular pressure (IOP) in sheep. ANIMALS: 20 healthy adult sheep. PROCEDURES: Diazepam with ketamine or propofol was given IV to each of 10 sheep after premedication with SRB (0.01 mg/kg, SC); after > 4 weeks, each sheep received the other induction combination with no premedication. For both eyes, IOPs were measured before premedication (if given), 10 minutes prior to (baseline) and immediately following administration of ketamine or propofol (time of IOA), after endotracheal intubation, and 5 minutes after IOA. Peak end-tidal P(CO2), globe position, and pupillary diameter were also analyzed. RESULTS: Data were not available for all sheep for all anesthetic episodes. Propofol-diazepam administration alone had no significant effect on IOP, whereas there was a significant decrease in IOP immediately following ketamine-diazepam administration alone. At 5 minutes after ketamine-diazepam administration, SRB-premedicated sheep had significantly higher IOP than unpremedicated sheep. Intraocular pressure was significantly higher at baseline, at intubation, and 5 minutes after IOA in SRB-premedicated sheep receiving propofol-diazepam, compared with unpremedicated sheep. Peak end-tidal P(CO2) at intubation was significantly higher in SRB-premedicated sheep. For sheep receiving either anesthetic treatment, IOPs did not differ significantly with or without SRB premedication. Globe position or pupillary diameter and IOP were not significantly related at any time point. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that both ketamine-diazepam and propofol-diazepam combinations were suitable for IOA without increasing IOP in sheep. The use of SRB should be avoided in sheep when increases in IOP are undesirable.

Effects of ketamine, a noncompetitive NMDA antagonist, on the acquisition of the lever-press response in rats.[Pubmed:7716221]

Physiol Behav. 1995 Feb;57(2):389-92.

We analyzed the effects of ketamine, a noncompetitive NMDA antagonist, on the acquisition of the lever-press response in the Skinner box and on motor performance both in the open field and in the inclined screen. Ninety-six adult male Wistar rats were assigned at random to eight different groups (n = 12). The first four groups received an acute intraperitoneal (IP) injection of: (a) physiological saline, (b) 4 mg/kg ketamine, (c) 8 mg/kg ketamine, or (d) 12 mg/kg ketamine, and the subjects were tested in a free lever-press response shaping in the Skinner box. The second four groups received the same substances and doses as the first four, but the subjects were tested for locomotor activity in an open field and tested immediately afterwards for motor performance in an 80 degrees inclined screen. Results showed that ketamine impaired the acquisition of the lever-press response in a dose-dependent manner, with no effects on ambulation in the open field nor on length of stay in the inclined screen. These results suggest that ketamine effects on the acquisition of the lever-press response cannot be attributed to a motor impairment, indicating a possible specific effect of ketamine on the associative learning acquisition.

The dissociative anaesthetics, ketamine and phencyclidine, selectively reduce excitation of central mammalian neurones by N-methyl-aspartate.[Pubmed:6317114]

Br J Pharmacol. 1983 Jun;79(2):565-75.

The interaction of two dissociative anaesthetics, ketamine and phencyclidine, with the responses of spinal neurones to the electrophoretic administration of amino acids and acetylcholine was studied in decerebrate or pentobarbitone-anaesthetized cats and rats. Both ketamine and phencyclidine selectively blocked excitation by N-methyl-aspartate (NMA) with little effect on excitation by quisqualate and kainate. Ketamine reduced responses to L-aspartate somewhat more than those of L-glutamate; the sensitivity of responses to these two putative transmitters was between that to NMA on one hand and that to quisqualate or kainate on the other. On Renshaw cells, ketamine and phencyclidine reduced responses to acetylcholine less than those to NMA but more than those to quisqualate or kainate. Dorsal root-evoked synaptic excitation of Renshaw cells was reduced to a greater extent than that following ventral root excitation. Intravenous ketamine, 2.5-20 mg/kg, and phencyclidine, 0.2-0.5 mg/kg, also selectively blocked excitation of neurones by NMA. Ketamine showed no consistent or selective effect on inhibition of spinal neurones by electrophoretically administered glycine or gamma-aminobutyricacid (GABA). The results suggest that reduction of synaptic excitation mediated via NMA receptors contributes to the anaesthetic/analgesic properties of these two dissociative anaesthetics.