Anesthesia Heart Rate Research Articles

An observational study on perfusion index to predict and correlate incidences of hypotension following spinal anaesthesia using pulse oximeter

Perfusion Index (PI) is the ratio of the pulsatile blood flow to the non-pulsatile or static blood in the peripheral tissues. It is a new parameter tried for predicting hypotension during spinal anaesthesia. Our aim was to observe Perfusion Index as an early predictor of hypotension under spinal anaesthesia in patients undergoing elective surgeries. In this observational study, 30 patients between the age group of 18-50years and belonged to ASA I and II category were taken. Spinal anaesthesia was performed with 3-4 ml of injection Bupivacaine 0.5% (hyperbaric) at L3–L4 interspace. Following spinal anaesthesia heart rate, blood pressure, and PI were recorded for 30 minutes. Hypotension was defined as fall in the MAP of 20% from the baseline and was treated with fluids, parasympatholytic ± vasopressors. Analysis was performed using software IBM SPSS statistics for windows, Data was presented as mean ± standard deviation. A P value < 0.05 was considered statistically significant. Regression analysis with Spearman’s rank correlation coefficient was done to assess the correlation between baseline PI and hypotension. Receiver operating characteristic (ROC) curve was plotted for PI and occurrence of hypotension.

Comparison of Intrathecal Dexmedetomidine and Fentanyl as Adjuvants to Hyperbaric Bupivacaine: A Randomised Controlled Trial

Introduction: Subarachnoid block using bupivacaine along with fentanyl is routinely used in regional anaesthesia technique in lower limb and lower abdominal surgeries. However, fentanyl is often associated with various side effects. The use of dexmedetomidine as an alternative to fentanyl in regional blocks is emerging due to minimal adverse effects and prolonged duration of action. Aim: To compare intrathecal dexmedetomidine and fentanyl as adjuvants to hyperbaric bupivacaine. Materials and Methods: The prospective, randomised study was performed on 100 patients, divided into two groups. Group I patients were administered with bupivacaine 12.5 mg (2.5 mL)+ fentanyl 25 μg (0.5 mL) whereas group II patients received bupivacaine 12.5 mg (2.5 mL) + dexmedetomidine 5 μg (0.5 mL). Post anaesthesia Heart Rate (HR) and Blood Pressure (BP) were recorded. The onset of sensory and motor block, level of sensory block, time for two segment regression, motor and sensor recovery, duration, quality of analgesia and Visual Analog Scale (VAS) score were recorded. Data were analysed using R Studio V 1.2.5001 software. Wilcoxon signed rank test and independent sample t-test were used to find the difference between mean. The p<0.05 was considered statistically significant. Results: Time for onset of sensory block (p=0.0027), motor block (p<0.001) and peak sensory block (p<0.001) was significantly high in group I patients. Most of the patients of group I had a T8 level of sensory block (38%) while in group II around 36% of patients had T6 level of sensory block. Time for full motor recovery (p=0.0015) and sensor recovery (p<0.001) was high in group II patients. Conclusion: Dexmedetomidine is associated with long term motor and sensory block, excellent analgesia and there was less demand for rescue analgesics as compared to fentanyl.

Guaiphenesin-ketamine-xylazine infusion to maintain anesthesia in mules undergoing field castration

BackgroundIn order to determine whether a combination of guaiphenesin, ketamine and xylazine can induce safe and satisfactory anaesthesia in mules undergoing field castration, eight healthy adult intact male mules were employed. They were premedicated with intravenous (IV) xylazine (1.3 mg/kg); an additional dose of xylazine (0.3 mg/kg IV) was administered in case of inadequate depth of sedation. Anaesthesia was induced with IV thiopental (6 mg/kg). The quality of sedation and induction was recorded. Anaesthesia was maintained with an infusion of guaiphenesin (50 mg/mL), ketamine (2 mg/mL) and xylazine (1 mg/mL) (GKX). The spermatic cord of each testis was infiltrated with 5 mL of 2% lidocaine. During anaesthesia heart rate (HR), respiratory rate (RR), rectal temperature (RT) and haemoglobin oxygen saturation (SpO2) were measured every 5 min. The data were analysed with simple one-way analysis of variance (ANOVA). A P value < 0.05 was considered statistically significant. Time of anesthesia, time of surgery and time of recovery were recorded.ResultsOnly one mule required an additional dose of xylazine to achieve a satisfactory depth of sedation. Thiopental at the dose of 6 mg/kg IV resulted in smooth induction and lateral recumbency in all animals. GKX provided adequate anaesthesia to perform castration in all mules. Muscle relaxation was deemed adequate and physiological variables remained stable and within references values during the anaesthesia and did not change in response to surgical stimulation. Time (mean ± standard deviation) from the end of the infusion to sternal recumbency and time from sternal recumbency to standing were 27.7 ± 4.6 and 30.1 ± 7.7 min, respectively.ConclusionsThe combination of xylazine, thiopental and GKX provides satisfactory short-term anaesthesia in mules undergoing field castration.

Cardiopulmonary effects during anaesthesia induced and maintained with propofol in acepromazine pre-medicated donkeys

ObjectiveTo evaluate the cardiopulmonary effects of anaesthesia induced and maintained with propofol in acepromazine pre-medicated donkeys. Study designProspective experimental study. AnimalsSix healthy male donkeys weighing 78–144 kg. MethodsDonkeys were pre-medicated with intravenous (IV) acepromazine (0.04 mg kg−1). Ten minutes later, anaesthesia was induced with IV propofol (2 mg kg−1) and anaesthesia maintained by continuous IV infusion of the propofol (0.2 mg kg−1 minute−1) for 30 minutes. Baseline measurements of physiological parameters, and arterial blood samples were taken before the acepromazine administration, then 5, 15, 30, 45, and 60 minutes after the induction of anaesthesia. Changes from baseline were analysed by anova for repeated measures. ResultsWhen compared with baseline (standing) values, during anaesthesia heart rate increased throughout: significant at 5 (p = 0.001) and 15 (p = 0.015) minutes. Mean arterial blood pressure increased significantly only at 15 minutes (p < 0.001). Respiratory rate and arterial pH did not change significantly. PaO2 was lower throughout anaethesia, but this only reached significance at 15 minutes (p = 0.041). PaCO2 was statistically (but not clinically) significantly reduced at the times of 30 (p = 0.02), 45 (p = 0.01) and 60 (p = 0.04). Rectal temperature decreased significantly at all times of the study. Conclusions and clinical relevanceAdministration of propofol by the continuous infusion rate for the maintenance of anaesthesia resulted in stable cardiopulmonary effects and could prove to be clinically useful in donkeys.

Fibrilación auricular inesperada al monitorizar en quirófano. Caso del trimestre

A real case reported to the SENSAR database of incidents is presented. In a patient scheduled for nose fracture repair surgery an unexpected atrial fibrillation was found when monitored in the operating room. The operation was not delayed. After induction of general anaesthesia heart rate suddenly increased and hemodinamic situation was impaired. Cardioversion was required. Two electric countershocks were given but sinus rhythm was not restored. Heart rate was controlled with amiodarone infusion. Optimal defibrillation characteristics are described in these cases. Increased risk of thromboembolism (1-2%) following cardioversion is present even if atrial thrombi are ruled out. The mainstay therapies of are rhythm and rate control and prevention of thromboembolic complications. We describe recommendations on the management of these critical situations with emphasis in learning through the creation of protocols and training practice in simulation.

A comparative study of hemodynamic changes between prone and supine emergence from anesthesia in lumbar disc surgery.

Background:Supine emergence from anesthesia in patients undergoing lumbar surgery in prone position leads to tachycardia, hypertension, coughing, laryngospasm and loss of monitoring as the patients are rolled back to supine position at the end of surgery. The prone extubation might facilitate a smoother emergence because the patients are not disturbed during emergence and secretions are drained away from patient's airway.Materials and Methods:The patients were randomly allocated to one of the two groups of 30 each at conclusion of surgery. First group was extubated in prone position and second in supine position at conclusion of surgery. Supine group patients were rolled back and prone group patients were left undisturbed. Extubation was done after complete reversal of neuromuscular block. Heart rates (HR), mean arterial pressure (MAP) were noted at various points of time. Coughing, laryngospasm, vomiting, monitor disconnection if any were also noted.Results:During emergence from anesthesia heart rate was significantly more in group S than group P at all intervals (P < 0.001). Mean arterial pressure was significantly higher in the supine group at 2, 3, and 4 min compared to prone group (P = 0.003). Compared to supine patients, prone patients had fewer incidences of coughing (P = 0. 0004), laryngospasm, vomiting and monitor disconnection.Conclusion:In healthy normotensive patients, emergence from anesthesia in the prone position is associated with minimal hemodynamic change, and fewer incidences of coughing, laryngospasm, and monitor disconnections.

Comparison of S(+)-ketamine and ketamine, with medetomidine, for field anaesthesia in the European brown hare (Lepus europaeus)

ObjectiveTo compare anaesthesia and recovery parameters of racemic ketamine or S(+)-ketamine in combination with medetomidine for intramuscular (IM) field anaesthesia in the European brown hare (EBH) (Lepus europaeus). Study designRandomized, prospective, blinded clinical trial. Animals20 adult EBH (eight male, 12 female), mean ± SD weight 3360 341). MethodsMedetomidine (0.2 mg kg−1) and ketamine (30 mg kg−1) (K-M group) or S(+)-ketamine (15 mg kg−1) (S-M group) were administered by IM injection. Time until first effect and loss of righting reflex were recorded. During sedation and anaesthesia heart rate, saturation of arterial haemoglobin, respiratory rate, side stream end tidal CO2 (Pe′CO2), non invasive blood pressure, body temperature, cardiorespiratory parameters, palpebral reflex, jaw tone and nociception were recorded every 5 minutes. Medetomidine was antagonized with IM atipamezole (1 mg kg−1) 45 minutes after treatment injection. Time until first head lift, standing and total recovery time (T-Recov) were recorded. Incidences of falling and involuntary movements during recovery were counted. Recovery quality was scored by visual analogue scale. Descriptive statistics were used to visualize maintenance data. All other data were included in multiple linear regression models. ResultsSurgical anesthesia was not produced reliably with either protocol. Hypoxaemia occurred in both groups (SpO2 < 90%). During recovery, falling was noted significantly less often (p < 0.001) in the S-M group (13 ± 7) versus the K-M group (27 ± 13). T-Recov was long, lasting for more than 3 hours in individuals with no significant differences between groups. Conclusion and clinical relevanceS(+)-ketamine showed only minor advantages over racemic ketamine. Surgical anaesthesia was not achieved reliably with either protocol. Oxygen supplementation should be considered to prevent hypoxaemia. Further research is needed to develop an injectable field protocol adequate for surgical procedures, but with a rapid smooth recovery.

Gabapentin reduces cardiovascular responses to laryngoscopy and tracheal intubation

We have compared the effects of gabapentin on arterial pressure and heart rate at induction of anaesthesia and tracheal intubation in a randomized double-blind study. Ninety normotensive patients (ASA I) undergoing elective surgery were divided into three groups of 30 patients each. Patients received oral placebo (Group I), 400 mg of gabapentin (Group II) or 800 mg of gabapentin (Group III) 1 h prior to surgery in the operating theatre. After induction of anaesthesia heart rate and mean arterial pressure were recorded at baseline 1, 3, 5, 10 and 15 min after intubation. Patients receiving placebo and 400 mg gabapentin showed a significant increase in blood pressure and heart rate associated with tracheal intubation compared to baseline levels and Group III. There was significant decrease in heart rate and arterial pressure in Group III after intubation 1, 3, 5 and 10 min (P < 0.001, P < 0.001, P < 0.05 and P < 0.05, respectively) compared to Groups I and II. Given 1 h before operation gabapentin 800 mg blunted the arterial pressure and heart rate increase in first 10 min due to endotracheal intubation. Oral administration of gabapentin 800 mg before induction of anaesthesia is a simple and practical method for attenuating pressor response to laryngoscopy and tracheal intubation after standard elective induction.

Comparison of detomidine/ketamine and guaiphenesin/thiopentone for induction of anaesthesia in horses maintained with halothane

This prospective clinical study compared the physiological effects of two commonly usedanaesthetic induction techniques in horses maintained with halothane. One hundred horses admitted for elective surgery were randomly allocated to...

Glycopyrrolate vs. atropine during anaesthesia for laryngoscopy and bronchoscopy

As glycopyrrolate has been reported superior to atropine with respect to reduction of salivation, stability of cardiac rate and rhythm, and recovery, a comparison of these properties of the two drugs and placebo was made in 45 patients undergoing direct laryngoscopy and 45 patients undergoing bronchoscopy, in most cases followed by mediastinoscopy. When given i.m. 30 min before anesthesia (midazolam, alfentanil, thiopentone, and suxamethonium), the two test drugs were found to be equally potent regarding the antisialogogic effect. The same increase in heart rate after the test drugs was seen before induction, and during anaesthesia heart rate rose to the same level in the placebo group as the test groups. During anaesthesia, blood pressure was lowest in the atropine group. No differences could be demonstrated with respect to cardiac arrhythmias, possibly due to the small size of the material. The present study gives no reason for preferring either drug, and only the efficacy of both test drugs in controlling airway secretions provides an argument for using any anticholinergic drug when laryngoscopy or bronchoscopy is performed under the conditions of the present study.

Haemodynamic effects of atropine during halothane or isoflurane anaesthesia in infants and small children.

In this study, two-dimensional and pulsed Doppler echocardiography were used to measure cardiovascular changes before and after IV atropine in 31 infants and small children during halothane (n = 15) or isoflurane (n = 16) anaesthesia. Prior to induction of anaesthesia heart rate (HR), mean blood pressure (MBP), and two-dimensional echocardiographic dimensions of the left ventricle and pulmonary artery blood flow velocity were measured by pulsed Doppler echocardiography. Cardiovascular measurements were repeated while anaesthesia was maintained at 1.5 MAC halothane (n = 15) or isoflurane (n = 16). Atropine 0.02 mg.kg-1 IV was then administered and two minutes later, a third set of cardiovascular data was obtained. Heart rate decreased during halothane anaesthesia but did not change significantly during isoflurane anaesthesia. Mean blood pressure, cardiac output (CO) and stroke volume (SV) decreased similarly during 1.5 MAC halothane or isoflurane anaesthesia. Ejection fraction (EF) decreased and left ventricular end-diastolic volume (LVEDV) increased significantly in both groups, but decreases in EF (32 +/- 5 per cent vs 18 +/- 5 per cent) and increases in LVEDV (18 +/- 7 per cent vs 7 +/- 5 per cent) were significantly greater during halothane than during isoflurane anaesthesia. Following atropine, HR increased more in the patients maintained with halothane (31 +/- 6 per cent), than during isoflurane anaesthesia (18 +/- 5 per cent). Atropine increased CO in both groups of patients, but SV and EF remained unchanged. When compared with awake values, HR increased similarly and significantly (18 +/- 4 per cent) following atropine in both groups, and CO returned to control levels.(ABSTRACT TRUNCATED AT 250 WORDS)