Premedication with intravenous low-dose ketamine suppresses fentanyl-induced cough

Prevention of sufentanil-induced cough during induction of general anesthesia by low-dose esketamine

BACKGROUND

Sufentanil is commonly used to induce general anaesthesia due to its rapid onset of action, strong analgesic effect, long-lasting effect, and stable haemodynamics; however, it often induces cough, increasing the risk of anaesthesia. This study aimed to investigate the preventive effect of low-dose esketamine on sufentanil-induced cough.

METHODS

This randomised, double-blind, placebo-controlled clinical study was conducted at the Air Force Medical Center between September 2023 and May 2024. A total of 100 adult patients (ASA of Anaesthesiologists class I-II) required general anaesthesia for elective surgery. The patients were randomly assigned to two groups: the esketamine group (Group E, n = 50), receiving 0.2 mg/kg esketamine intravenously, and the control group (Group C, n = 50), receiving an equal volume of normal saline. The incidence and severity of sufentanil-induced cough were assessed 1 min after administering of 0.5 μg/kg sufentanil intravenously. Heart rate (HR), mean arterial pressure (MAP), and adverse reactions were recorded at four time points: before esketamine administration (T0), 3 min after esketamine administration (T1), 1 min after endotracheal intubation (T2), and 3 min after endotracheal intubation (T3). The results were analyzed using appropriate statistical methods.

RESULTS

A total of 100 eligible patients were screened, of which 99 participated in this study (1 patient refused to participate), 50 in Group E, and 49 in Group C. The incidence of cough in Group E (6.0%) was significantly lower than that in Group C (34.7%) (P < 0.001), and the severity of cough was also significantly milder than that in Group C (P = 0.038). The differences in the HR and MAP levels at T0, T1, T2, and T3 between the two groups were not statistically significant (P > 0.05). Two patients in Group C experienced chest wall stiffness, while no adverse reactions were observed in Group E. The difference in the incidence of adverse reactions between the two groups was not statistically significant (P > 0.05).

CONCLUSION

Low-dose esketamine (0.2 mg/kg) can significantly reduce the incidence of sufentanil-induced cough during the induction of general anaesthesia in patients, with a small impact on haemodynamics, no adverse reactions, and good safety.

Inhibitory effect of low-dose esketamine on cough induced by sufentanil during the induction of anesthesia and postoperative impact on mental health status: a prospective, single-center, randomized controlled trial

BACKGROUND

Intravenous administration of sufentanil during anesthesia induction induces cough (SIC), sometimes triggers a severe reaction. We wanted to investigate the inhibitory effect of low-dose esketamine on cough induced by sufentanil during the induction of general anesthesia, as well as its postoperative impact on mental status (MMSE score, RSS, and VAS-A).

METHODS

A total of 256 adult patients were randomly allocated to receive either esketamine (Group EK) or normal saline (Group C). One minute before the administration of sufentanil, Group EK and Group C were injected with esketamine (0.05 mg/kg, diluted with normal saline to 3 ml) and normal saline (3 ml), respectively. The primary outcomes were the incidence (the basis of the presence or absence of cough) and severity (the frequency of cough episodes) of cough within 2 min after sufentanil injection.The secondary outcomes included hemodynamic variables (MAP, HR, and SPi), mental status (MMSE score, RSS, and VAS-A) and postoperative events (time to awareness, duration of orientation recovery and degree of satisfaction with anesthesia).

RESULTS

A total of 236 adult patients were randomized into two groups (n = 236): Group EK (n = 118) and Group C (n = 118). The incidence of cough in Group EK (21.2%) was significantly lower than that in Group C (40.7%) (P < 0.05). The incidence rates for each grade were as follows: 9.3% and 16.9% for Grade 2, and 0% and 4.2% for Grade 3, respectively.The differences had statistical senses.The MAP and HR at T4 (during tracheal intubation) and T5 (1 min post-intubation) were significantly lower in Group EK (P < 0.05). There were no significant differences in MMSE score, RSS, and VAS-A, time to awareness, duration of orientation recovery or satisfaction with anesthesia.

CONCLUSION

Pretreatment with low-dose esketamine can reduce the incidence and severity of cough induced by sufentanil and maintain hemodynamic stability during anesthesia induction without increasing mental status (MMSE score, RSS, and VAS-A).

TRIAL REGISTRATION

Chinese Clinical Trial Registry (ChiCTR2400084940, date of registration: 05/28/2024).

Effect of pretreatment with a small dose of esketamine on sufentanil-induced cough during anesthesia induction: a randomized controlled trial

BACKGROUND

Sufentanil-induced cough is common during the induction of anesthesia. The objective of this study was to determine whether pretreatment with a small dose of esketamine is effective in treating sufentanil-induced cough.

METHODS

220 patients were screened, and 200 patients who had scheduled elective surgery and were between 18 and 70 years old were randomly divided into two groups. Before sufentanil was administered, esketamine group (group K) was injected with 0.15 mg/kg esketamine at 5 s, and control group (group C) was administered with the same volume. Within 1 min after sufentanil(0.4ug/kg) injection during induction, cough incidence and severity were evaluated. After sufentanil was injected, we recorded its hemodynamic changes and side effects.

RESULTS

In the esketamine group (group K) and control group (group C), there was an incidence of cough of 5 and 34%, respectively. The esketamine group (group K) had a significantly lower incidence and severity of cough compared to the control group (group C) immediately after sufentanil injection (P < 0.05). MAP and HR did not differ significantly between the two groups during three different times of general anesthesia induction (P > 0.05).

CONCLUSION

In our study, we found that sufentanil-induced cough was significantly reduced by pretreatment with 0.15 mg/kg esketamine, but with no significant changes in the hemodynamic status.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (ChiCTR2200063821, registered date: 17/09/2022), http://www.chictr.org.cn.

Analgesic Effect of Intraoperative Intravenous S(+)-Ketamine During Total Knee Arthroplasty Surgery: Study Protocol for a Randomized Controlled Clinical Trial

BACKGROUND

Total knee arthroplasty (TKA) is currently the main treatment for end-stage knee disease. The number of cases of TKA in China increased from 53,880 in 2011 to 374,833 in 2019, representing a 5.9-fold increase. Moderate to severe pain often occurs after TKA, which seriously affects postoperative rehabilitation, patient satisfaction, and overall outcome. Multimodal analgesia is considered the ideal solution. Adequate postoperative analgesia can not only reduce pain, opioid consumption, and, consequently, opioid-related adverse events, but can also reduce the length of hospital stay and costs and improve rehabilitation and patient satisfaction.

OBJECTIVE

Effective multimodal pain management in the early postoperative period is essential for anesthesiologists. Additional studies have demonstrated that a low-dose intravenous infusion of ketamine can be administered as an adjuvant drug to alleviate acute postoperative pain. Therefore, we aim to appraise the efficacy and safety of intraoperative intravenous injection of S(+)-ketamine to relieve acute pain after TKA in older patients.

METHODS

This is a protocol for a randomized, placebo-controlled trial. A total of 144 participants aged 65 years and older undergoing TKA will be randomly allocated into the S(+)-ketamine and placebo groups in a 1:1 ratio. S(+)-ketamine or the placebo will be intravenously administered at 0.3 mg/kg/h during the operation by anesthesiologists. Blinded evaluation by trained investigators will be completed at 2 hours, 24 hours, and 48 hours after surgery. The primary outcome measure will be the numeric rating scale score at rest and movement at 24 hours after surgery. The secondary outcomes will include the numeric rating scale scores at rest and movement at 2 hours and 48 hours after surgery, the number of patients who require additional analgesics during the first 48 hours after operation, the total consumption of opioids or nonsteroid anti-inflammatory drugs during the first 48 hours after operation, and adverse events at 2, 24, and 48 hours after operation.

RESULTS

The protocol was registered at Clinical Trials.gov on February 26, 2022. It was performed in accordance with the approved guidelines and regulations of the participating institutions. Recruitment began in April 2022. Data collection is expected to conclude in September 2024. Study completion is expected in December 2024.

CONCLUSIONS

A randomized, controlled, clinical study was designed to observe the analgesic effect of intraoperative intravenous administration of a lower dose of S(+)-ketamine (0.3 mg/kg/h) in older patients after TKA surgery. The protocol will appraise the efficacy and safety of intraoperative intravenous injection of S(+)-ketamine to relieve acute pain after TKA in older patients who may benefit from the administration of S(+)-ketamine.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05289050; https://clinicaltrials.gov/ct2/show/NCT05289050.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/53063.

Comparison of the effects of intravenous propofol and propofol with low-dose ketamine on preventing postextubation cough and laryngospasm among patients awakening from general anaesthesia: A prospective randomised clinical trial

BACKGROUND

Coughing and laryngospasm are undesirable consequences occurring when patients awaken from general anaesthesia. The objective of the study aimed to compare the effects of intravenous propofol and propofol with low-dose ketamine on preventing postextubation cough and laryngospasm.

METHODS

In all, 120 patients scheduled surgery under general anaesthesia were randomly assigned into three groups. Patients in the control group (C-group) received intravenous 0.9% NaCl, while patients in the propofol group (P-group) received intravenous 0.25mg/kg propofol and patients in the propofol combined with ketamine group (PK-group) received intravenous 0.25mg/kg of propofol plus 0.15mg/kg of ketamine. Drugs were administered before extubation. Incidence and severity of coughing and laryngospasm were recorded by a blinded anaesthesiologist.

RESULTS

Subjects of the PK-group (25%) experienced significantly reduced incidence of postoperative cough than that in the P-group (55%) and C-group (72.5%) (all P < 0.05). The severity of cough in the PK-group was significantly less than that in the P-group and C-group (P = 0.039 and P < 0.001, respectively). No significant difference was found in the incidence and severity of laryngospasm between comparison groups.

CONCLUSION

Intravenous combination of propofol and low-dose ketamine significantly reduced the incidence and severity among patients awakening from general anaesthesia.

Low-dose lidocaine attenuates fentanyl-induced cough: A double-blind randomized controlled trial

PURPOSE

The study aimed to determine the efficacy of lidocaine at different low doses to reduce fentanyl-induced cough (FIC).

METHODS

Three hundred twenty patients aged from 18 to 60 years with ASA I and II scheduled for general anesthesia were randomly assigned to 4 groups to obtain peripheral intravenous 0.9%NaCl (Group I), lidocaine 0.25 mg/kg (Group II), 0.5 mg/kg (Group III) or 1.0 mg/kg (Group IV) 2 min before 3 μg/kg of fentanyl intravenously in a prospective randomized controlled fashion. The primary result was incidence of cough among comparison groups. The secondary results included severity of cough, hemodynamic response and risk factors of FIC.

RESULTS

Thirty-two, 15, 13 and 11 patients (40, 18.8, 16.3 and 13.8%) presented incidence of cough in Groups I, II, III and IV, respectively (P < 0.05 Group I vs. II, III and IV). No significant difference was observed in the incidence and severity of cough among the lidocaine groups (P > 0.05). Multivariate analysis showed that age ≤ 40 years, nonsmoking and patients not receiving the prior lidocaine injection were risk factors of FIC (P = 0.007, 0.013 and 0.001, respectively).

CONCLUSION

The study implied intravenous lidocaine 0.25 mg/kg for 2 min before fentanyl injection was the most effective dose to suppress FIC and could be applied in daily practice. Patients aged less than 40 years and nonsmoking were risk factors of FIC, regardless of sex and underlying disease.

Clinical effects of low-dose esketamine for anaesthesia induction in the elderly: A randomized controlled trial

WHAT IS KNOWN AND OBJECTIVE

Esketamine is an N-methyl-D-aspartic acid (NMDA) receptor antagonist, which has stronger sedative and analgesic effects and fewer adverse events than ketamine. The effects of low-dose esketamine on haemodynamics and postoperative quality of recovery in elderly patients have not been evaluated. To evaluate whether low-dose esketamine can be safely used for anaesthesia induction in the elderly.

METHODS

Eighty elderly patients were selected for unilateral total knee replacement under general anaesthesia from February 2021 to August 2021. Patients were randomly divided into two groups (n = 40): control group (C group) and esketamine group (K group). During induction of anaesthesia, the control group was intravenously injected with normal saline of equal volume, and the esketamine group was intravenously injected with 0.2-mg/kg esketamine. Both groups were induced by etomidate, sufentanil and rocuronium and maintained by combined intravenous and inhaled anaesthesia during operation.

MAIN OUTCOME MEASURES

HR, SBP, DBP, MAP and BIS values were recorded before induction of anaesthesia (T₀ ), immediately before endotracheal intubation (T₁ ), 1min(T₂ ) and 5min(T₃ ) after endotracheal intubation, surgical skin incision (T₄ ), 1min(T₅ ) and 5min(T₆ ) after surgical skin incision.

RESULTS

Compared with the C group, SBP, DBP, MAP, HR and BIS of the K group were significantly higher at T₁ -T₃ (p < 0.05). There were no significant differences in SBP, DBP, MAP, HR and BIS between the two groups at T₄ -T₆ (p > 0.05). Compared with T₀ , SBP, MAP and BIS values of the two groups at T₁ -T₆ were decreased (p < 0.05). DBP of the K group at T₂ was not significantly different from DBP at T₀ (p < 0.05), but DBP of the C group decreased from T₁ to T₆ (p < 0.05). Compared with T₀ , HR in both groups decreased at T₁ , T₃ , T₄ , T₅ and T₆ (p < 0.05). Compared with the C group, the incidence of cough in the K group was significantly lower (p < 0.05); There was no significant difference in the number of myoclonus during induction between the two groups (p > 0.05). Compared with the C group, the number of hypotension episodes in the K group during induction was much smaller (p < 0.05). There were no significant differences in the incidence of hypertension, bradycardia and tachycardia (p > 0.05). There were no significant differences in postoperative recovery quality and incidence of adverse events between the two groups (p > 0.05).

WHAT IS NEW AND CONCLUSION

Low-dose esketamine for anaesthesia induction in the elderly undergoing knee arthroplasty may better maintain the stability of haemodynamics and has no adverse effect on the quality of early recovery after operation.

Comparison of Five Prophylactically Intravenous Drugs in Preventing Opioid-Induced Cough: A Bayesian Network Meta-Analysis of Randomized Controlled Trials

Background: Due to the absence of direct comparisons of different therapeutic drugs in preventing opioid-induced cough (OIC) during the induction of general anesthesia, clinicians often faced difficulties in choosing the optimal drug for these patients. Hence, this network meta-analysis was conducted to solve this problem.

Methods: Online databases, including Pubmed, Embase, Web of Science, Cochrane, and Google Scholar, were searched comprehensively to identify eligible randomized controlled trials (RCTs), up to March 15th, 2021. Within a Bayesian framework, network meta-analysis was performed by the “gemtc” version 0.8.2 package of R-3.4.0 software, and a pooled risk ratio (RR) associated with 95% credible interval (CrI) was calculated.

Results: A total of 20 RCTs were finally enrolled, and the overall heterogeneity for this study was low to moderate. Traditional pair-wise meta-analysis results indicated that all of the five drugs, namely, lidocaine, ketamine, dezocine, butorphanol, and dexmedetomidine could prevent OIC for four clinical outcomes, compared with the placebo (all p-values < 0.05). Moreover, dezocine had the best effect, compared with that of the other drugs (all p-values < 0.05). Network meta-analysis results suggested that the top three rank probabilities for four clinical outcomes from best to worst were dezocine, butorphanol, and ketamine based on individual/cumulative rank plots and surface under the cumulative ranking curve (SUCRA) probabilities. The node-splitting method indicated the consistency of the direct and indirect evidence.

Conclusions: Our results indicated that all of these five drugs could prevent OIC compared with the placebo. Moreover, the top three rank probabilities for four clinical outcomes from best to worst were dezocine, butorphanol, and ketamine. Our results were anticipated to provide references for guiding clinical research, and further high-quality RCTs were required to verify our findings.

Systematic Review Registration: [https://www.crd.york.ac.uk/prospero/], identifier [CRD42021243358].

Perioperative management of patients with asthma during elective surgery: A systematic review

Asthma is one of the commonest respiratory illnesses among elderly patients undergoing surgery. Detailed preoperative assessment, pharmacotherapy and safe anaesthetic measures throughout perioperative period are the keys to decrease complications. Resistance to expiratory airflow results in positive alveolar pressures at the end of expiration, which causes air-trapping and hyperinflation of the lungs and thorax, increased work of breathing, and alteration of respiratory muscle function. This systematic review was conducted according to the Preferred Reporting Items for systematic review and metanalysis (PRISMA) statement. Search engines like PubMed through HINARI, Cochrane database and Google Scholars were used to find evidences. Low-dose IV ketamine, midazolam, IV lidocaine or combined with salbutamol are recommended to be used as premedication before induction. Propofol, ketamine, halothane, isoflurane and sevoflurane are best induction agents and maintenance for asthmatic surgical patients respectively. Among the muscle relaxants, vecuronium is safe for use in asthmatics. In addition, Succinylcholine and pancronium which releases low levels of histamine has been used safely in asthmatics with little morbidity.

Comparison of Two Dosages of Ketamine in Preventing Fentanyl-Induced Coughs in Children

BACKGROUND

Fentanyl is a short-acting drug used to induce anesthesia. Here, we aimed to compare the two doses of ketamine to prevent fentanyl-induced cough in children under general anesthesia.

MATERIALS AND METHODS

This is a randomized, clinical trial which was performed in 2019 in Imam Hossein Hospital in Isfahan, Iran. The study population consisted of children between 6 months and 2 years who were candidates for general anesthesia. Patients were randomized into three groups, each containing 31 patients. Groups 1 and 2 received 0.1 mg/kg and 0.2 mg/kg intravenous ketamine, respectively, 1 min before fentanyl injections. Group 3 received the same volumes of normal saline 0.9%. Patients were observed and evaluated for the incidence and intensity of coughs 1 min and 3 min after fentanyl injections.

RESULTS

We showed that the frequency of coughs 1 min after fentanyl injection was significantly lower in Group 2 compared to other groups (P < 0.001). Three min after fentanyl injection, the frequencies of coughs were significantly lower in Groups 1 and 2 compared to Group 3 (P < 0.001). We also showed that the intensity of coughs was significantly lower in Group 2 compared to other Groups 1 and 3 min after fentanyl injection (P < 0.001).

CONCLUSION

The administration of 0.2 mg/kg ketamine is more effective than 0.1 mg/kg dosage in the prevention of fentanyl-induced cough. We also showed that this method could bring more stable hemodynamics and oxygenation saturation inpatients. The comparison of the two dosages was a novel issue in the recent literature.

Comparison of lidocaine, huffing maneuver and combination of both in prevention fentanyl induced cough before induction of anesthesia: a double-blind, prospective, randomized placebo-controlled study

BACKGROUND

Intravenous bolus injection of fentanyl has been frequently reported to be associated with cough reflex during patient anesthesia. However, the search for the most effective protocol continues. This study aimed to compare the effect of reducing cough reflex after injection of fentanyl in a fusion protocol by combining the injections of lidocaine and Huffing maneuver and comparing with a placebo control group, before anesthesia induction.

METHODS

This prospective randomized controlled trial study was performed on 400 patients who were divided into four groups of combined protocol (group 1), lidocaine group (group 2), Huffing maneuver group (group 3), and the control receiving normal saline (group 4). Then patients were injected with 2. 5 μg /kg fentanyl and monitored for 2 min regarding their cough reflex, as well as the severity.

RESULTS

In group one, 9 patients (9%), in group two, 45 patients (45%), 22 patients (22%) in group three, and in group four, 75 patients (75%), developed cough reflex following fentanyl injection. Also, 13 patients (13%) developed moderate and 4 (4%) developed severe coughs in the control group reported, while no reports of severe or moderate cough were among the intervention groups. There was a significant difference between the intervention group and the control group both in terms of the rate and severity of the fentanyl-induced cough.

CONCLUSION

By using a combination of lidocaine injection along and Huffing maneuver, better results can be obtained in reducing the frequency, and also the severity of cough followed by fentanyl injection.

TRIAL REGISTRATION

The trial was registered with IRCT.IR (09/03/2018-No. IRCT20141009019470N74 ).

Intubating conditions and hemodynamic changes during awake fiberoptic intubation using fentanyl with ketamine versus dexmedetomidine for anticipated difficult airway: a randomized clinical trial

Background and objectives

Awake fiberoptic intubation (AFOI) is usually performed in patients with an anticipated difficult airway. Various sedation regimens are used during AFOI, however, most of them cause respiratory depression. The present study aims to compare the effectiveness of fentanyl with ketamine versus dexmedetomidine in search of a better sedation regimen which would achieve desirable intubating conditions and hemodynamic stability without causing respiratory depression.

Methods

This is a single centered randomized, double-blind clinical trial. Patients of both sexes between age 18–55 years and ASA (American Society of Anesthesiologists) physical status I–II with an anticipated difficult airway were randomly divided into two groups of thirty each. Group FK patients received intravenous fentanyl and ketamine, and group DX patients received dexmedetomidine, until Ramsay sedation scale ≥ 2. Heart rate (HR), mean blood pressure (MBP), oxygen saturation (SpO₂), respiratory rate (RR), endoscopy time, intubation time, first end-tidal carbon dioxide (ETCO₂) after intubation, endoscopist satisfaction score, and patient discomfort score were recorded during the study period. The level of recall was assessed on the next postoperative day.

Results

Endoscopist satisfaction score was better in group DX patients (p < 0.05). There was a smaller variation in HR and MBP from baseline with dexmedetomidine compared to fentanyl with ketamine. First ETCO₂ after intubation was higher in group FK patients (p <  0.05). No significant difference was found in patient discomfort score, intubation time, RR, SpO₂ and level of recall of the event.

Conclusions

The use of dexmedetomidine in AFOI provides better intubating conditions and hemodynamic stability compared to fentanyl with ketamine.

Mechanism and Management of Fentanyl-Induced Cough

Fentanyl-induced cough (FIC) often occurs after intravenous bolus administration of fentanyl analogs during induction of general anesthesia and analgesia procedure. The cough is generally benign, but sometimes it causes undesirable side effects, including elevated intra-abdominal, intracranial or intraocular pressure. Therefore, understanding the related mechanisms and influencing factors are of great significance to prevent and treat the cough. This paper reviews the molecular mechanism, influencing factors and preventive administration of FIC, focusing on the efficacy and side effects of various drugs in inhibiting FIC to provide some medical reference for anesthesiologists.

Effects of Low-dose Propofol or Ketamine on Coughing at Emergence from Anesthesia in Children Undergoing Tonsillectomy

Introduction Coughing is commonly observed during emergence from general anesthesia. In children, smooth emergence from anesthesia, especially after tonsillectomy, is crucial. In this study, we compared the effect of low-dose ketamine or propofol on emergence coughing in children undergoing tonsillectomy. Methods In this randomized clinical trial, 90 children undergoing tonsillectomy were randomly allocated into two groups: children in group A received 0.5-mg/kg propofol and children in group B received 0.5-mg/kg ketamine, at the end of anesthesia. The incidence and severity of cough, postoperative sedation, nausea, and vomiting, and pain score were recorded and compared. Results The incidence of no cough at emergence from anesthesia was 82.2% in the propofol group and 15.5% in the ketamine group (P = 0.00). Children in the ketamine group exhibited postoperative pain but were more sedated compared with those in the propofol group (P > 0.05). The incidence of postoperative nausea and vomiting was lower in the propofol group (P < 0.05). Conclusions At the end of general anesthesia with isoflurane in children undergoing tonsillectomy, 0.5-mg/kg propofol is more effective than 0.5-mg/kg ketamine in reducing cough response upon emergence from anesthesia, with a lower incidence of nausea and vomiting, as well as lower sedation in children.

Conditioned medium from overly excitatory primary astrocytes induced by La3+ increases apoptosis in primary neurons via upregulating the expression of NMDA receptors

Lanthanum (La) can accumulate in the brain and impair learning and memory. However, the underlying mechanism of La-induced neurotoxicity has remained elusive. Under physiological conditions, it has been reported that moderately excitatory astrocytes play an important role in the regulation of neuronal signals and synaptic plasticity. However, under pathological conditions, overly excitatory astrocytes can release excess excitatory transmitters, such as glutamate (Glu) and d-serine, and induce the over-activation of NMDA receptors (NMDAR) in neurons, ultimately leading to neuronal excitotoxicity. To date, limited work has been performed with respect to whether La can induce neuronal excitotoxicity by inducing astrocytes to become overexcited. In this study, in vitro models of primary culture rat cortical astrocytes and neurons were established. First, the astrocytes were treated with 0.125 mM, 0.25 mM and 0.5 mM lanthanum chloride (LaCl3) for 24 h, and the supernatants were collected as a conditioned medium (CM) which is denoted as CM (La3+); then, the neurons were treated with CM (La3+) for 48 h. The results illustrate that LaCl3 treatment significantly upregulated the mRNA and protein expression levels of metabotropic glutamate receptor 5 (mGLUR5), phospholipase C (PLC), connexin 43 (Cx43) and Cx30, increased the concentrations of inositol trisphosphate (IP3) and [Ca2+]i, and promoted the synthesis and release of Glu and d-serine in astrocytes. Moreover, the CM (La3+) could increase the mRNA and protein expression levels of NMDAR subunits (NR1, NR2A, NR2B), the concentration of [Ca2+]i and the rate of apoptosis in neurons. Furthermore, after removal of La, CM (La-free) had a similar effect on neurons which could be antagonized by MK-801, DCKA and DAAO. These results suggest that the neuron apoptosis induced by La is closely related to the excessive release of Glu and d-serine from overly excitatory astrocytes.

Optimal dose of pretreated-dexmedetomidine in fentanyl-induced cough suppression: a prospective randomized controlled trial

BACKGROUND

To investigate the optimal dose of pretreated-dexmedetomidine in fentanyl-induced cough (FIC) suppression.

METHODS

Patients of 180 undergoing elective surgery with general anesthesia, aged 18-65 years, BMI 18.5-30 kg/m2, ASA I or II, were equally randomized into four groups (n = 45) to receive intravenous pretreatment of dexmedetomidine with 0 (group 1), 0.3 (group 2), 0.6 (group 3) and 0.9 (group 4) mcg/kg over 10 mins, respectively. After the pretreatment, all patients were given a 5-s intravenous injection of fentanyl 4 mcg/kg. The symptoms of irritating cough including the severity and onset time were recorded for 1 min after fentanyl injection. General anesthesia induction was completed with midazolam, propofol and cisatracurium, then endotracheal tube or laryngeal mask was inserted and connected to an anesthesia machine. MAP, HR and SpO2 at the beginning of pretreatment (T0), 3 min (T1), 6 min (T2), 9 min (T3) and 12 min (T4) after the beginning of pretreatment were recorded. Side effects of dexmedetomidine, such as bradycardia, hypertension, hypotension, and respiratory depression were also recorded during the course.

RESULTS

Totally 168 patients completed the study. The incidences of cough were 52.4, 42.9, 11.9, and 14.3% in groups 1, 2, 3, and 4, respectively, with no significant differences between groups 1 and 2 (P > 0.05) and between groups 3 and 4 (P > 0.05). The incidence and severity of cough in groups 3 and 4 were significantly lower than those in groups 1 and 2 (P < 0.05). Compared to T0, HR at T2 (P < 0.05), T3 (P < 0.01), and T4 (P < 0.01) decreased significantly and MAP at T4 decreased significantly (P < 0.05) in group 4. Bradycardia occurred in 1 case and respiratory depression occurred in 1 case in group 4. Compared to group 1, the onset time of cough in the other 3 groups were delayed significantly (P < 0.05).

CONCLUSION

Pretreated dexmedetomidine 0.6 mcg/kg blous intravenous infusion over 10 mins could reduce FIC effectively without side effects.

TRIAL REGISTRATION

This study was registered in ClinicalTrials.gov (NCT03126422), April 13, 2017.

Comparison of the effects of oxycodone versus fentanyl on airway reflex to tracheal extubation and postoperative pain during anesthesia recovery after laparoscopic cholecystectomy: A double-blind, randomized clinical consort study

BACKGROUND

Fentanyl has been suggested to be effective for controlling airway and hemodynamic responses to tracheal extubation. This study was performed to compare the effects of oxycodone and fentanyl on airway and hemodynamic responses and postoperative pain during the recovery period in patients undergoing laparoscopic cholecystectomy.

METHODS

Ninety patients aged 18 to 65 years were randomly allocated to 1 of 3 groups: fentanyl, oxycodone, and control. Coughing responses (incidence and severity), hemodynamic responses during the recovery period, and acute postoperative pain were assessed.

RESULTS

The incidence of cough was decreased in the fentanyl and oxycodone groups compared with that in the control group at the points of awareness and extubation, and no significant difference was observed between the 2 treatment groups. Severe cough response was decreased in the fentanyl and oxycodone groups compared with that in the control group at the point of extubation, and no significant change was observed in cough severity between the 2 treatment groups. Postoperative pain scores were lower in the fentanyl and oxycodone groups than those in the control group at 5 and 30 minutes postoperatively, and no significant difference was observed between the 2 treatment groups. Hemodynamic responses did not differ among the 3 groups during the recovery period.

CONCLUSION

Oxycodone treatment before tracheal extubation reduced cough response and was as effective as fentanyl treatment for improving extubation quality. Furthermore, single boluses of fentanyl and oxycodone showed equal effectiveness in attenuating acute postoperative pain in patients undergoing laparoscopic cholecystectomy.

Comparison of Lidocaine and Atropine on Fentanyl-Induced Cough: A Randomized Controlled Study

Objective of the Study: Fentanyl and atropine are drugs used for analgesia during induction and for premedication, respectively. The aim of this study was to observe the effect of atropine used for premedication on cough developing in association with fentanyl use during anesthesia induction. Methods: This was a single-blind, prospective, multi-arm, parallel, randomized clinical trial involving 120 patients between ages 3 and 15 years undergoing general anesthesia. Patients were randomized into three groups: a control group (Group C), an atropine group (Group A), and a lidocaine group (Group L). Results: Incidence of cough was 45% (n = 16) in Group C, 16% (n = 6) in Group A, and 16% in Group L (n = 6) (p = 0.009). Cough was moderate in two cases in Group A and in two in Group L, and mild in all others in these groups. In Group C, cough was mild in seven cases, moderate in six, and severe in two. Conclusion: We determined that premedication with atropine suppressed the incidence and severity of fentanyl-induced cough during induction of general anesthesia. We think that, due to its antimuscarinic effect, atropine is as effective as lidocaine as a premedication.

Pheniramine Maleate is more effective than Lidocaine on Fentanyl Induced Cough

OBJECTIVE

Fentanyl is frequently used during anesthesia induction. The use of fentanyl can cause cough through different mechanisms. Here, we aimed to investigate effects of pheniramine maleate (PM), an antihistaminic agent, and compare it with lidocaine on fentanyl induced cough.

METHODS

This is a randomized double-blind prospective clinical study of ASA I-II, 120 patients scheduled for elective abdominal surgery. Patients were administered drugs intravenously and randomly allocated into three groups: Group C (2 ml 0.9 % normal saline), Group L (1mg/kg lidocaine), and Group F (PM 45.5 mg). 90 seconds after administration, 2µ/kg fentanyl was applied in three seconds to all patients. Severity of cough (mild: 1-2, moderate: 3-5, severe> 5), time of the cough and vital parameters were recorded 90 seconds after fentanyl injection.

RESULTS

Eight patients (25%) in Group C had fentanyl induced cough whereas three patients (7.5%) in Group L and one patient (2.5%) in Group F experienced this phenomenon. There was statistically significant difference between Group F and Group C (p<0.05); however, differences between Group L and Group C or Group F and Group L were not statistically significant (p>0.05).

CONCLUSIONS

Pheniramine Maleate 45.5 mg is better that placebo and as effective as lidocaine to prevent fentanyl induced cough.

Different interventions in preventing opioid-induced cough: a meta-analysis

BACKGROUND

Cough is one of the most common complications of opioids. Many studies have evaluated the effect of various drugs in preventing opioid-induced cough (OIC). However, there is existing controversy about those reports. The present study was performed to assess the efficacy of different interventions on OIC.

METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, and Embase to identify randomized controlled trials on the efficacy of different drugs in the prevention of OIC. Opioids included fentanyl, sufentanil, and remifentanil. We mainly investigated the incidence and severity of OIC after different interventions.

RESULTS

Thirty-four trials including 9906 patients were analyzed in this study. Twenty different drugs were reported, and 10 drugs were indentified in more than 2 articles. These drugs, including lidocaine, ketamine, dexmedetomidine, priming of fentanyl, propofol, dezocine, dexamethasone, dextromethorphan, and magnesium sulfate (MgSO4), showed a significant efficacy compared with controls. There were insufficient numbers of trials for salbutamol, clonidine, tramadol, pentazocine, rocuronium, midazolam, atropine, terbutaline, sodium chromoglycate, beclomethasone, and ephedrine. From these data, we found that salbutamol, tramadol, midazolam, and atropine were ineffective.

CONCLUSIONS

This meta-analysis suggested that the prophylactic administration of lidocaine, ketamine, dexmedetomidine, priming of fentanyl, propofol, and dezocine was effective in preventing OIC.

Butorphanol suppresses fentanyl-induced cough during general anesthesia induction: A randomized, double-blinded, placebo-controlled clinical trial

Fentanyl-induced cough (FIC) is unwanted in the patients requiring stable induction of general anesthesia. This study was designed to evaluate the suppressive effects of butorphanol pretreatment on the incidence and severity of FIC during the induction of general anesthesia. A total of 315 patients of American Society of Anesthesiologists physical status I and II, scheduled for elective surgery under general anesthesia were randomized into 3 equally sized groups (n = 0105). Two minutes before fentanyl bolus, group I received intravenously 5 mL normal saline, groups II and III received butorphanol 0.015 and 0.03 mg/kg (diluted with saline to 5 mL), respectively. Patients were then administrated with fentanyl 2.5 μg/kg within 5 s. The incidence and severity of FIC was recorded for 2 minutes after fentanyl bolus. During experimental period, the mean arterial pressure, heart rate, and peripheral capillary oxygen saturation (SpO2) were recorded before the administration of butorphanol or normal saline (T0), 2 minutes (T1) after butorphanol injection, and 2 minutes (T2) after fentanyl injection. The incidence of FIC was 31.4% in group I, 11.4% in group II, and 3.8% in group III. Group III had a lowest incidence of FIC among 3 groups (P < 0.001, vs group I; P < 0.05, vs group II). The severe FIC was not observed in groups II and III, but was recoded from 6 patients in group I. At 2 minutes after fentanyl injection (T2), the mean arterial pressure was significantly higher in group I than that in groups II and III (P < 0.01, vs group II; P < 0.05, vs group III), but the values remained within safe limits. In conclusion, pretreatment with butorphanol could effectively and safely suppress FIC during anesthesia induction.

[The effect of pheniramine on fentanyl-induced cough: a randomized, double blinded, placebo controlled clinical study]

BACKGROUND AND OBJECTIVES

There are many studies conducted on reducing the frequency and severity of fentayl-induced cough during anesthesia induction. We propose that pheniramine maleate, an antihistaminic, may suppress this cough. We aim to observe the effect of pheniramine on fentanyl-induced cough during anesthesia induction.

METHODS

This is a double-blinded, prospective, three-arm parallel, randomized clinical trial of 120 patients with ASA (American Society of Anesthesiologists) physical status III and IV who aged ≥18 and scheduled for elective open heart surgery during general anesthesia. Patients were randomly assigned to three groups of 40 patients, using computer-generated random numbers: placebo group, pheniramine group, and lidocaine group.

RESULTS

Cough incidence differed significantly between groups. In the placebo group, 37.5% of patients had cough, whereas the frequency was significantly decreased in pheniramine group (5%) and lidocaine group (15%) (Fischer exact test, p=0.0007 and p=0.0188, respectively). There was no significant change in cough incidence between pheniramine group (5%) and lidocaine group (15%) (Fischer exact test, p=0.4325). Cough severity did also change between groups. Post Hoc tests with Bonferroni showed that mean cough severity in placebo differed significantly than that of pheniramine group and lidocaine group (p<0.0001 and p=0.009, respectively). There was no significant change in cough severity between pheniramine group and lidocaine group (p=0.856).

CONCLUSION

Intravenous pheniramine is as effective as lidocaine in preventing fentayl-induced cough. Our results emphasize that pheniramine is a convenient drug to decrease this cough.

The effects of propofol, ketamine and combination of them in prevention of coughing and laryngospasm in patients awakening from general anesthesia: A randomized, placebo-controlled, double blind clinical trial

BACKGROUND

Coughing and laryngospasm are undesirable outcomes occurring during emergence from general anesthesia. We compared the effect of small doses of propofol, ketamine and a combination of them on the occurrence and severity of coughing and laryngospasm in patients awakening from general anesthesia.

MATERIALS AND METHODS

160 patients who were scheduled to undergo operations under general anesthesia were randomly assigned to one of the following groups, 40 in each group: propofol group (0.25 mg/kg intravenous (IV) propofol), ketamine group (0.25 mg/kg IV ketamine), combination group (0.25 mg/kg IV propofol, and 0.25 mg/kg IV ketamine) and control (0.1 ml/kg IV saline). Drugs were administered before extubation at previously defined time. Presence and severity of coughing and laryngospasm were recorded within twominutes after extubation.

RESULTS

The presence of coughing in the combination group (27.5%) was less than that in other groups; also it was less frequent in the propofol group (57.5%) than the control (82.5%) (all P < 0.05). But the incidence did not differ between the propofol and the ketamine (70%) group; nor did it differ between the ketamine and control groups (P = 0.356 and P = 0.121, respectively). The cases with severe coughing (grade 3) in the combination group (none) were significantly less than in the propofol (four) and the control groups (seven) (P = 0.040 and P = 0.006 respectively). There was no significant difference between the groups in frequency of laryngospasm.

CONCLUSION

Administration of propofol or combination of propofol and ketamine decreases the incidence of post extubation coughing. This combination can also decrease severe cases.

Can low dose of propofol effectively suppress fentanyl-induced cough during induction of anaesthesia? A double blind randomized controlled trial

Background and Aims:

Fentanyl-induced cough (FIC) is often seen after intravenous (IV) administration of fentanyl during the induction of general anesthesia. The aim of this study was to evaluate the effectiveness of low dose of propofol in suppressing of FIC during induction of anesthesia.

Material and Methods:

In a prospective double-blind randomized controlled trial, a total of 240 patients, American Society of Anesthesiologists physical status Class I and II, scheduled for elective surgery were randomly assigned into two equally sized groups (n = 120). Patients in Group A received low dose of propofol (10 mg) and patients in Group B received the same volume of normal saline (control group). Two minutes later, all patients were given fentanyl (2 μg/kg) over 2 s through the peripheral IV line in the forearm. The vital sign profiles and frequency and intensity of cough were recorded within 2 min after fentanyl bolus by a nurse blinded to study design. Data were analyzed using independent t-test, paired t-test and Chi-square test.

Results:

The incidences of FIC were 9.2% and 40.8% in Group A (propofol) and Group B (placebo) respectively (P = 0.04). Furthermore, there was a significant difference in the intensity of cough between Groups A and B (P < 0.0001). The hemodynamic value (systolic blood pressure, diastolic blood pressure, heart rate, mean arterial pressure and saturation of oxygen) were similar, and there was no significant difference between two groups in the baseline value or after propofol or placebo injection.

The effect of pheniramine on fentanyl-induced cough: a randomized, double blinded, placebo controlled clinical study

BACKGROUND AND OBJECTIVES

There are many studies conducted on reducing the frequency and severity of fentayl-induced cough during anesthesia induction. We propose that pheniramine maleate, an antihistaminic, may suppress this cough. We aim to observe the effect of pheniramine on fentanyl-induced cough during anesthesia induction.

METHODS

This is a double-blinded, prospective, three-arm parallel, randomized clinical trial of 120 patients with ASA (American Society of Anesthesiologists) physical status III and IV who aged ≥18 and scheduled for elective open heart surgery during general anesthesia. Patients were randomly assigned to three groups of 40 patients, using computer-generated random numbers: placebo group, pheniramine group, and lidocaine group.

RESULTS

Cough incidence differed significantly between groups. In the placebo group, 37.5% of patients had cough, whereas the frequency was significantly decreased in pheniramine group (5%) and lidocaine group (15%) (Fischer exact test, p=0.0007 and p=0.0188, respectively). There was no significant change in cough incidence between pheniramine group (5%) and lidocaine group (15%) (Fischer exact test, p=0.4325). Cough severity did also change between groups. Post Hoc tests with Bonferroni showed that mean cough severity in placebo differed significantly than that of pheniramine group and lidocaine group (p<0.0001 and p=0.009, respectively). There was no significant change in cough severity between pheniramine group and lidocaine group (p=0.856).

CONCLUSION

Intravenous pheniramine is as effective as lidocaine in preventing fentayl-induced cough. Our results emphasize that pheniramine is a convenient drug to decrease this cough.

Effect of memantine on cough reflex sensitivity: translational studies in guinea pigs and humans

Cough is the most common complaint for which outpatients in the United States seek medical attention, and yet available therapeutic options for cough lack proven efficacy and are further limited by safety and abuse liabilities. Thus, safe and effective cough suppressants are needed. Recent preclinical studies described the antitussive effects of memantine, an N-methyl-d-aspartate receptor channel blocker used in the treatment of Alzheimer's disease. The goals of the present study were to compare the antitussive effects of memantine, dextromethorphan, and codeine in guinea pigs; to relate the dose-dependent actions of memantine in these studies to peak plasma concentrations achieved following oral administration; and to provide the first ever evaluation of the antitussive effect of memantine in humans. In guinea pigs, memantine and codeine were comparable in efficacy and potency but both were superior to dextromethorphan in the citric acid cough challenge model. The pharmacokinetic analyses suggest that memantine was active in guinea pigs at micromolar plasma concentrations. Subsequently, 14 healthy volunteers as well as 14 otherwise healthy adults with acute viral upper respiratory tract infection (URI) underwent capsaicin cough challenges 6 hours after ingestion of 20 mg memantine and matched placebo in a randomized, double-blind, crossover fashion. In healthy volunteers, memantine significantly inhibited cough reflex sensitivity (P = 0.034). In subjects with URI, responsiveness to capsaicin was markedly increased, and in these patients, the inhibition of cough reflex sensitivity by memantine relative to placebo did not reach statistical significance (P = 0.088). These data support further research to investigate the potential of memantine as a clinically useful antitussive.

Pharmacological and nonpharmacological prevention of fentanyl-induced cough: a meta-analysis

Fentanyl-induced cough (FIC) is often observed after intravenous bolus administration of fentanyl during anesthesia induction. This meta-analysis assessed the efficacy of pharmacological and nonpharmacological interventions to reduce the incidence of FIC. We searched for randomized controlled trials comparing pharmacological or nonpharmacological interventions with controls to prevent FIC; we included 28 studies retrieved from Pub-Med, Embase, and Cochrane Library. Overall incidence of FIC was approximately 31 %. Lidocaine [odds ratio (OR) = 0.29, 95 % confidence interval (CI) 0.21–0.39], N-methyl-D-aspartate (NMDA) receptor antagonists (OR 0.09, 95 % CI 0.02–0.42), propofol (OR 0.07, 95 % CI 0.01–0.36), a2 agonists (OR 0.32, 95 % CI 0.21–0.48), b2 agonists (OR 0.10, 95 % CI 0.03–0.30), fentanyl priming (OR 0.33, 95 % CI 0.19–0.56), and slow injection of fentanyl (OR 0.25, 95 % CI 0.11–0.58)] were effective in decreasing the incidence of FIC, whereas atropine (OR 1.10, 95 % CI 0.58–2.11) and benzodiazepines (OR 2.04, 95 % CI 1.33–3.13) were not effective. This meta-analysis found that lidocaine, NMDA receptor antagonists, propofol, a2 agonists, b2 agonists, and priming dose of fentanyl were effective in preventing FIC, but atropine and benzodiazepines were not. Slow injection of fentanyl was effective in preventing FIC, but results depend on the speed of administration.

A priming dose of intravenous ketamine-dexmedetomidine suppresses fentanyl-induced coughing: a double-blind, randomized, controlled study

OBJECTIVE

This study was designed to investigate whether a priming dose of ketamine-dexmedetomidine can effectively suppress fentanyl-induced coughing (FIC).

METHODS

Altogether 400 patients of ASA I and II, aged 18-70 years, undergoing various elective surgical procedures, were randomly allocated into four groups of 100 patients each. Patients in the placebo group received volume-matched normal saline 0.15 mL/kg + normal saline 0.05 mL/kg. One group of patients was given ketamine 0.15 mg/kg + normal saline 0.05 ml/kg (KET), and another group dexmedetomidine 0.5 μg/kg + normal saline 0.05 ml/kg (DEX). Finally, one group of patients received ketamine 0.15 mg/kg + dexmedetomidine 0.5 μg/kg (KETODEX). After fentanyl administration, the onset time and severity of cough for 1 min were recorded. Cough severity was graded as mild (grade 1-2), moderate (grade 3-5), or severe (grade >5).

RESULT

The incidence of FIC was 53%, 34%, 20%, and 9% in the placebo, DEX, KET, and KETODEX groups, respectively. The incidence of cough was significantly lower in the KETODEX group. Likewise, the onset time of cough was significantly delayed in the KETODEX group. Only nine patients in the KETODEX group had either mild (6%) or moderate (3%) cough, with none suffering from severe cough.

CONCLUSION

A priming dose of KETODEX effectively suppressed the cough reflex induced by fentanyl and delayed the onset time of cough. Therefore, treatment with KETODEX may be a clinically useful method for preventing FIC.

Comparison of the effects of ketamine or lidocaine on fentanyl-induced cough in patients undergoing surgery: A prospective, double-blind, randomized, placebo-controlled study

BACKGROUND

Fentanyl-induced cough is common but has not been viewed as a serious anesthetic problem. However, the cough may be explosive at times, may require immediate intervention, and may be associated with undesirable increases in intracranial, intraocular, and intra-abdominal pressures. Prevention of fentanylinduced cough in such situations is of paramount importance. Ketamine, at concentrations achieved with standard clinical doses, has a direct relaxant effect on airway smooth muscle.

OBJECTIVE

This study was designed to assess the effects of ketamine or lidocaine on fentanyl-induced cough.

METHODS

This double-blind, randomized, placebo-controlled study was conducted at the Erciyes University Medical School, Kayseri, Turkey. Consecutive adult patients aged 18 to 65 years and classified as American Society of Anesthesiologists physical status I or II who were undergoing elective surgery with general anesthesia were enrolled. Patients were randomly allocated equally into 3 groups to receive lidocaine 1 mg/kg, ketamine 0.5 μg/kg, or placebo intravenously 1 minute before fentanyl administration. Following intravenous fentanyl (1.5 μg/kg over 2 seconds) injection, an observer, unaware of the type of medication given to the patients, recorded the number of episodes of coughing, if any. Any episode of cough was classified as coughing and graded by investigators blinded to treatment as mild (1-2 coughs), moderate (3-4), or severe (≥5). Blood pressure, heart rate, pulse oximetry oxygen saturation (SpO2), and adverse effects (AEs) were recorded.

RESULTS

A total of 368 patients were approached for inclusion; 300 patients met the inclusion criteria and were enrolled in the study. No patients in the ketamine group had cough. The frequency of cough was significantly lower in the lidocaine (11/100 [11%]; P = 0.024) and ketamine (0/100; P = 0.001) groups compared with the placebo group (23/100 [23%]). The intensity of cough was significantly lower in the lidocaine (mild, 7/100 [7%]; moderate, 4/100 [4%]; P = 0.037) and ketamine (0/100; P < 0.001) groups compared with the placebo group (mild, 10/100 [10%]; moderate, 12/100 [12%]; severe, 1/100 [1%]). Severe cough (≥5) was observed in 1 patient in the placebo group. Incidence and intensity of cough were significantly decreased in the ketamine group compared with the lidocaine group (incidence, P = 0.001; intensity, P = 0.003). There were no significant differences between groups with respect to systolic blood pressure, diastolic blood pressure, heart rate, SpO2, and AEs.

CONCLUSION

Intravenous ketamine (0.5 mg/kg) significantly reduced the reflex cough induced by fentanyl compared with lidocaine and placebo, and was well tolerated.

A comparison of the effect of pretreatment with intravenous dexamethasone, intravenous ketamine, and their combination, for suppression of remifentanil-induced cough: A randomized, double-blind, placebo-controlled clinical trial

Background:

The injection of remifentanil can cause cough during induction of anesthesia. This study was designed to examine the efficacy of ketamine, dexamethasone, and their combination on remifentanil-induced cough (RIC).

Materials and Methods:

One hundred and twenty patients scheduled for elective surgery were randomly assigned into four groups: Group K received 10 mg ketamine; Group D received 10 mg dexamethasone; Group KD received 10 mg ketamine in combination with dexamethasone; and Group S received saline in a similar volume, five minutes prior to the injection of remifentanil. The incidence and severity of the cough was recorded in each person.

Results:

The incidence of RIC was significantly lower in Group KD compared to Group K, Group D, and Group S (3.3 vs. 20%, 20%, and 46.7%, respectively, P < 0.05). The severity of RIC was significantly lower in Group KD compared to Group K, Group D, and Group S (P < 0.05). There was no significant difference between Group K and Group D in this regard (P > 0.05). There was no significant difference in the onset time of coughing among the four groups (19.8 ± 1.3, 20.8 ± 0.9, 19.0 ± 1.1, and 19.9 ± 2.2 in Group K, Group D, Group KD, and Group S, respectively, P > 0.05).

Conclusion:

We found that pretreatment with 10 mg ketamine in combination with 10 mg dexamethasone five minutes prior to the injection of remifentanil could significantly reduce the incidence of RIC, and it was better than using each drug singly.

Propofol is Effective to Depress Fentanyl-Induced Cough during Induction of Anesthesia

BACKGROUND

Various attempts have been made to reduce the incidence of fentanyl-induced cough during anesthesia induction. We hypothesized that an appropriate dose of propofol might suppress fentanyl-induced cough.

OBJECTIVES

A study had been designed to observe the effects of propofol on a fentanyl-induced cough during anesthesia induction.

PATIENTS AND METHODS

We performed a randomized, double-blind study to evaluate the effect of the pre-emptive use of minimal dose intravenous propofol (20 mg) on the incidence of cough caused by a larger bolus of intravenous fentanyl. Group 1 patients were given fentanyl at a dosage of 4 µg/kg. Group 2 received 4µg/kg fentanyl and 20 mg propofol. The two groups were evaluated in 0, 5 and 10 second intervals following the injection of fentanyl.

RESULTS

Mean age, weight, and, height was 35 ± 10.45, 67.99 ± 10.92, and 165.33 ± 31.84 respectively. The incidence of fentanyl induced cough was 29 (74.4%) in placebo group compared with 10 (25.6%) in the propofol group. There was a significant difference in the incidence and severity of cough between group 1 and 2 (P < 0.0001). This study also showed that propofol could decrease cough incidence in patients who smoke.

CONCLUSIONS

Priming dose of propofol (20mg) one minute prior to fentanyl injection was effective in suppressing a fentanyl-induced cough.

Effects of different priming doses of fentanyl on fentanyl-induced cough: a double-blind, randomized, controlled study

BACKGROUND

Fentanyl-induced cough is not an uncommon phenomenon during the induction of general anesthesia. A preliminary randomized controlled study was designed to observe the effects of different priming doses of fentanyl on fentanyl-induced cough during induction of anesthesia.

METHODS

Four hundred patients were randomized into four groups (n = 100 for each). Group I received 5 ml saline 0.9% 1 min before administration of fentanyl 2.5 μg/kg; group II received pre-emptive fentanyl 0.5 μg/kg 1 min before administration of fentanyl 2 μg/kg; group III received pre-emptive fentanyl 1 μg/kg 1 min before administration of fentanyl 1.5 μg/kg; and group IV received pre-emptive fentanyl 1.5 μg/kg 1 min before administration of fentanyl 1 μg/kg. The severity of cough was graded as none (0), mild (1-2), moderate (3-4), or severe (5 or more episodes). We defined T1 and T2 as the 1 min periods after the first and second injections, respectively, and recorded the number of patients whose first cough happened in the T1 or T2 period.

RESULTS

The incidences of fentanyl-induced cough were 68%, 5%, 40% and 64% in groups I, II, III and IV, respectively. The incidence of cough in group II was lower than those in groups III and IV in the T1 period. The incidences of cough in groups II, III and IV were lower than that in group I in the T2 period.

CONCLUSIONS

In summary, a priming dose of fentanyl 0.5 μg/kg suppressed fentanyl-induced cough during induction of anesthesia in clinical practice. Fentanyl-induced cough was positively correlated with the dose of fentanyl.

Effects of a priming dose of fentanyl during anaesthesia on the incidence and severity of fentanyl-induced cough in current, former and non-smokers

Fentanyl is commonly used during anaesthesia and can cause fentanyl-induced cough (FIC). This study investigated whether a priming dose of fentanyl reduced FIC, and determined the factors associated with increased risk of FIC. Subjects undergoing elective surgery under general anaesthesia (n = 800) were randomized into four groups: group 1 received 2 μg/kg fentanyl bolus; groups 2, 3 and 4 received a priming dose of fentanyl 0.5 μg/kg followed by 1.5 μg/kg after 1, 2 or 3 min, respectively. The incidence of FIC was 17.0%, 10.0%, 12.5% and 11.5% for groups 1, 2, 3 and 4, respectively, with no significant between-group differences in FIC incidence or severity. The mean FIC onset time was 22 s. Former smokers were 2.91 times more likely than current smokers to experience cough. A fentanyl priming dose did not reduce the incidence and severity of FIC. Former smokers were hyper-reactive to fentanyl compared with current smokers.

Chest wall rigidity in two infants after low-dose fentanyl administration

Since its introduction into clinical practice, it has been known that fentanyl and other synthetic opioids may cause skeletal muscle rigidity. Involvement of the respiratory musculature, laryngeal structures, or the chest wall may impair ventilation, resulting in hypercarbia and hypoxemia. Although most common with the rapid administration of large doses, this rare adverse effect may occur with small doses especially in neonates and infants. We present 2 infants who developed chest wall rigidity, requiring the administration of neuromuscular blocking agents and controlled ventilation after analgesic doses of fentanyl. Previous reports regarding chest wall rigidity after the administration of low-dose fentanyl in infants and children are reviewed, the pathogenesis of the disorder is discussed, and treatment options offered.

Premedication with intravenous dexmedetomidine-midazolam suppresses fentanyl-induced cough

BACKGROUND

The incidence of fentanyl-induced cough (FIC) occurs frequently during induction of general anesthesia, and methods to prevent it are needed. In this study, we hypothesized that premedication with intravenous dexmedetomidine-midazolam can suppress FIC effectively.

METHODS

A total of 440 patients of ASA I or II, aged 18-65 years, weighing 41-90 kg, undergoing elective surgery were randomized into four groups of 110 each, using computer-generated random numbers. Group S + S: normal saline 0.15 ml/kg + normal saline 0.06 ml/kg; Group S + M: normal saline 0.15 ml/kg + midazolam 0.06 mg/kg; Group D + S: dexmedetomidine 0.6 μg/kg + normal saline 0.06 ml/kg; Group D + M: dexmedetomidine 0.6 μg/kg + midazolam 0.06 mg/kg. After receiving the above-mentioned drugs, all patients received i.v. fentanyl (3 μg/kg). After fentanyl administration, the onset time and the severity of cough for 1 min were recorded. Severity of coughing was graded as mild (1-2), moderate (3-5) and (>5) based on the number of cough per minute.

RESULTS

Forty-five (40.9%) patients had cough in Group S + S, 70 (63.6%) in Group S + M and 25 (22.7%) in Group D + S. None of the patients in Group D + M had any cough. The total incidence of cough was significantly higher (P < 0.01) in Group S + M in comparison to that in other groups. The onset time of cough was significantly shorter in Group S + M (13.8 ± 3.8 s) than in Group S + S (18.7 ± 3.9 s, P < 0.01) or Group D + S. (18.2 ± 3.2 s, P < 0.01). However, there was no significant difference among groups in cough severity.

CONCLUSIONS

Pretreatment with dexmedetomidine-midazolam could completely suppress FIC caused by fentanyl 3 μg/kg injection within 2 s.

Effect of intravenous dezocine on fentanyl-induced cough during general anesthesia induction: a double-blinded, prospective, randomized, controlled trial

PURPOSE

To evaluate the suppressive effect of intravenous dezocine on fentanyl-induced cough during the induction of general anesthesia.

METHODS

A total of 120 patients, American Society of Anesthesiologists (ASA) physical status I-II, were randomized into two equally sized groups (n = 60). These two groups were given either intravenous dezocine 0.1 mg/kg or a matching placebo (equal volume of 0.9% saline) 10 min before the induction of general anesthesia. Patients were induced with midazolam 0.1 mg/kg, fentanyl 5 μg/kg, propofol 1-1.5 mg/kg, and suxamethonium 1.5 mg/kg. The injection time of fentanyl was less than 2 s in all patients. The occurrence of cough was recorded 2 min after fentanyl bolus.

RESULTS

No patient in the dezocine group had cough, and 42 patients in the control group had cough. This difference was statistically different between these two groups (P = 0.000).

CONCLUSION

These results demonstrate that intravenous dezocine 0.1 mg/kg 10 min prior to induction was effective in suppressing fentanyl-induced cough in our patients.

Pharmacologic therapy for cough

Cough is the commonest symptom for which patients seek medical care and yet effective, well-tolerated cough medicines remain a significant unmet clinical need. The development of anti-tussive agents has probably been restricted by a number of factors; our understanding of the specific mechanisms evoking cough in different diseases and how this differs from the role of cough as a protective reflex is limited. Also well-validated tools for the assessment of cough have been lacking. These issues have not encouraged investment by the pharmaceutical industry and there have been no new licensed treatments for cough in more than 50 years. This article will use a mechanism-based approach to discuss the clinical evidence for the anti-tussive activity of currently available agents.

Effects of different priming doses of propofol on fentanyl-induced cough during anesthesia induction: a preliminary randomized controlled study

Fentanyl-induced cough is not an uncommon condition during the induction of general anesthesia. A preliminary randomized controlled study was designed to observe the effects of different priming doses of propofol on fentanyl-induced cough during anesthesia induction. A total of 120 patients were randomized into 4 groups (n = 30) to receive the intravenous injection of intralipid (group I), propofol 1 mg.kg(-1) (group II), propofol 1.5 mg.kg(-1) (group III), or propofol 2 mg.kg(-1) (group IV) 1 minute before a bolus of fentanyl 2.5 microg.kg(-1). The occurrence and severity of cough were recorded for 2 minutes after fentanyl bolus. The severity of cough was graded as none (grade 0), mild (grade 1-2), moderate (grade 3-4), or severe (grade 5 or more). The average bolus time of fentanyl was 1.5 +/- 0.3 seconds in the present study. The incidence of fentanyl-induced cough was 80.0% in group I, 40.0% in group II, 6.7% in group III, and 3.3% in group IV, respectively. Groups II, III, and IV had a lower incidence and less severity of cough than group I (P < 0.05). Groups III and IV had a lower incidence and less severity of cough than group II (P < 0.05). In summary, a priming dose of more than 1 mg.kg(-1) of propofol is effective to suppress fentanyl-induced cough in a dose-dependent manner. We suggest using a priming dose of propofol 1.5 mg.kg(-1) to suppress cough during the anesthesia induction with propofol and fentanyl in clinical practice.

The effect of pre-emptive use of minimal dose fentanyl on fentanyl-induced coughing

We performed a randomised, double-blind study to evaluate the effect of the pre-emptive use of minimal dose intravenous fentanyl (25 microg) on the incidence of cough caused by a larger bolus of intravenous fentanyl. Six hundred patients were randomly assigned to one of three groups to receive either 0.5 ml saline 0.9% 1 min before administration of fentanyl 150 microg (3 ml), or pre-emptive fentanyl 25 microg (0.5 ml) 1 min before administration of fentanyl 125 microg or 150 microg. The incidence of fentanyl-induced cough was significantly lower in both pre-emptive groups (7 (3.5%) for 125 microgfentanyl and 15 (7.5%) for 150 microg fentanyl) than in the saline group (37 (18.5%); p = 0.001). We conclude that pre-emptive use of fentanyl 25 microg, administered 1 min before bolus injection of fentanyl (125 or 150 microg), can effectively suppress fentanyl-induced cough.

Effect of low dose ketamine to prevent remifentanil-induced cough: a randomized, double-blind, placebo controlled trial

BACKGROUND

A reflex cough is often observed after an intravenous (IV) bolus of remifentanil. Since ketamine was reported to be effective in modulating the cough reflex, this prospective, randomized, double-blind, placebo-controlled study was designed to evaluate the efficacy of pretreatment with ketamine on remifentanil-induced cough.

METHODS

320 patients undergoing general anesthesia for elective surgery were randomly allocated into two groups to receive either IV ketamine 0.1 mg/kg (ketamine group, n = 156) or 0.9% saline (saline group, n = 154) 1 min before administration of remifentanil at a target effect-site concentration of 5 ng/ml. Severity of cough was graded (mild, 1-2; moderate, 3-4; and severe, 5 or >5).

RESULTS

The overall incidence of cough was significantly higher in the saline group (43/154 patients; 0.28, 95% CI 0.21, 0.36) than that in the ketamine group (18/156 patients; 0.12, 95% CI 0.07, 0.18) (P < 0.001). However, there was no significant difference in the severity and the onset time of cough between the groups.

CONCLUSIONS

IV ketamine 0.1 mg/kg one minute before remifentanil was effective in suppressing remifentanil-induced cough without affecting the severity and onset time.