Perioperative Pain Control: A Strategy for Management

Comparison of the Effect of Ketamine, Ketamine-Midazolam and Ketamine-Propofol on Post-Tonsillectomy Agitation in Children

Background

Emergence agitation (EA) in children is one of the most common complications following anaesthesia. We aimed to compare the effect of ketamine, ketamine-midazolam and ketamine-propofol on EA after tonsillectomy.

Methods

This study was a randomised, double-blind clinical trial conducted on 162 children undergoing adenotonsillectomy surgery. The participants were randomly divided into three groups of receiving ketamine (0.5 mg/kg) (N = 54), ketamine (0.5 mg/kg) + propofol (1 mg/kg) (N = 54) and ketamine (0.5 mg/kg) + midazolam (0.01 mg/kg) (N = 54) 10 min before the end of the operation. At the time of the patients’ entry into the post-anaesthesia care unit (PACU) and at intervals of 5 min, 10 min and 20 min after that, consciousness, mobility, breathing, circulation and SpO₂ were recorded. Modified Aldrete recovery score (MARS), the objective pain score (OPS) and Richmond agitation-sedation scale (RASS) were also evaluated.

Results

At the time of entrance to the PACU and 5 min later, the ketamine-midazolam and ketamine-propofol groups had lower RASS scores than the ketamine group (P < 0.001); after 10 min and 20 min, the ketamine-propofol group showed the lowest RASS score (P < 0.001). Ketamine-propofol group had a significantly lower MARS score at all-time points (P < 0.001). Recovery time was the longest for the ketamine-propofol group (P = 0.008).

Conclusion

The ketamine-midazolam group had lower RASS, greater haemodynamic stability and MARS values without delayed awakening.

Effect of administering dexmedetomidine with or without atropine on cardiac troponin I level in isoflurane-anesthetized dogs

We aimed to determine whether dexmedetomidine administration with or without atropine increases cardiac troponin I (cTnI) level in healthy dogs. We hypothesized that 10 µg/kg dexmedetomidine + atropine increases the cTnI level, whereas 5 µg/kg dexmedetomidine + atropine does not. Eighteen healthy, pet dogs that underwent an orthopedic surgery or ovariohysterectomy were included in this study. The dogs were randomly assigned to atropine (0.02 mg/kg)–dexmedetomidine (10 µg/kg), saline–dexmedetomidine (10 µg/kg), and atropine (0.02 mg/kg)–dexmedetomidine (5 µg/kg) groups. Each dog was premedicated with atropine or saline intramuscularly (IM). After 10 min, they were IM injected with dexmedetomidine (10 or 5 µg/kg)–morphine (0.5 mg/kg)–midazolam (0.2 mg/kg). Following this, anesthesia was induced after 10 min with propofol and maintained with isoflurane in 100% oxygen. The median plasma cTnI level at 6, 12 and 24 hr after premedication was significantly higher than that at baseline. The cTnI level in the atropine–dexmedetomidine (10 µg/kg) group was significantly higher than that in the saline–dexmedetomidine (10 µg/kg) and atropine–dexmedetomidine (5 µg/kg) groups at 6 and 12 hr after premedication. The cTnI level returned to normal within 72 hr after premedication in all groups. The administration of atropine in combination with 10 µg/kg dexmedetomidine increased the cTnI level, indicating subclinical myocardial damage.

A preliminary assessment of vital-signs-integrated patient-assisted intravenous opioid analgesia (VPIA) for postsurgical pain

Background

We developed a Vital-signs-integrated Patient-assisted Intravenous opioid Analgesia (VPIA) analgesic infusion pump, a closed-loop vital signs monitoring and drug delivery system which embodied in a novel algorithm that took into account patients’ vital signs (oxygen saturation, heart rate). The system aimed to allow responsive titration of personalized pain relief to optimize pain relief and reduce the risk of respiratory depression. Moreover, the system would be important to enable continuous monitoring of patients during delivery of opioid analgesia.

Methods

Nineteen patients who underwent elective gynecological surgery with postoperative patient controlled analgesia (PCA) with morphine were recruited. The subjects were followed up from their admission to the recovery room/ ward for at least 24 h until assessment of patient satisfaction on the VPIA analgesic infusion pump.

Results

The primary outcome measure of incidence of oxygen desaturation showed all patients had at least one episode of oxygen desaturation (< 95%) during the study period. Only 6 (31.6%) patients had oxygen desaturation that persisted for more than 5 min. The median percentage time spent during treatment that oxygen saturation fell below 95% was 1.9%. Fourteen (73.7%) out of 19 patients encountered safety pause, due to transient oxygen desaturation or bradycardia. The patients’ median [IQR] pain scores at rest and at movement after post-op 24 h were 0.0 [2.0] and 3.0 [2.0], respectively. The average morphine consumption in the first 24 h was 12.5 ± 7.1 mg. All patients were satisfied with their experience with the VPIA analgesic infusion pump.

Conclusions

The use of VPIA analgesic infusion pump, when integrated with continuous vital signs monitor and variable lockout algorithm, was able to provide pain relief with good patient satisfaction.

Trial registration

This study was registered on clinicaltrials.gov registry (NCT02804022) on 28 Feb 2016.

Non-Opioid Perioperative Pain Strategies for the Clinician: A Narrative Review

Alternative and non-opioid options for pain management are necessary in perioperative patient care. Opioids are no longer touted as cure-all medications, and furthermore, there have been tremendous advances in alternative therapies such as in interventional pain, physical therapy, exercise, and nutritional counseling that have proven benefits to combat pain. The center for disease control now strongly recommends the use of multimodal analgesia and multidisciplinary approaches based on the individual needs of patients: personalized medicine. In this manuscript, the specifics of non-opioid pharmacological and non-pharmacological analgesic approaches will be discussed as well as their possible indications and uses to reduce the need for excessive use of opioids for adequate pain control.

Effects of low-dose intraoperative fentanyl on postoperative respiratory complication rate: a pre-specified, retrospective analysis

BACKGROUND

Fentanyl is one of the most frequently administered intraoperative drugs and may increase the risk of postoperative respiratory complications (PRCs).

METHODS

We performed a pre-specified analysis of 145 735 adult non-cardiac surgical cases under general anaesthesia. Using multivariable logistic regression, we evaluated the association of intraoperative fentanyl dose and PRCs within 3 days after surgery (defined as reintubation, respiratory failure, pneumonia, pulmonary oedema, or atelectasis). We examined effect modification by patient characteristics, surgical site, and anaesthetics used.

RESULTS

PRCs within 3 days after surgery occurred in 18 839 (12.9%) patients. In comparison with high intraoperative fentanyl doses [median: 3.85; inter-quartile range (IQR): 3.42-4.50 μg kg^-1, quartile 4 (Q4)], low intraoperative fentanyl dose [median: 0.80, IQR: 0.00-1.14 μg kg^-1, quartile 1 (Q1)] was significantly associated with lower odds of PRCs [Q1 vs Q4: 10.9% vs 16.2%; adjusted odds ratio (aOR) 0.79; 95% confidence intervals (CI) 0.75-0.84; P<0.001; adjusted absolute risk difference (aARD) -1.7%]. This effect was augmented by thoracic surgery (P for interaction <0.001; aARD -6.2%), high doses of inhalation anaesthetics (P for interaction=0.016; aARD -2.2%) and neuromuscular blocking agents (NMBAs) (P for interaction=0.001; aARD -3.4%). Exploratory analysis demonstrated that compared with no fentanyl, low-dose fentanyl was associated with lower rates of PRCs (decile 2 vs decile 1: aOR 0.82, CI 0.75-0.89, P<0.001).

CONCLUSIONS

Intraoperative low-dose fentanyl (about 60-120 μg for a 70 kg patient) was associated with lower risk of postoperative respiratory complications compared with both no fentanyl and high-dose fentanyl. Beneficial effects of low-dose fentanyl were magnified in specific patient subgroups.

CLINICAL TRIAL REGISTRATION

NCT03198208.

Comparison of tapentadol with tramadol for analgesia after cardiac surgery

Background:

Tapentadol is a relatively new analgesic. We decided to compare it with tramadol for their various effects after cardiac surgery.

Setting:

A study in a tertiary care hospital.

Materials and Methods:

Sixty adults undergoing cardiac surgery were divided into 2 groups of 30 each by computerized random allotment (Group X = tapentadol 50 mg oral and Group Y = tramadol 100 mg oral). Informed Consent and Institutional Ethics Committee approval were obtained. The patients were given either drug X or drug Y after extubation in this single blinded study, wherein the data collectors and analyzers were blinded to the study. All patients received oral paracetamol qds and either drug X or drug Y tds. The pain score was noted on a Visual Analog Scale before each drug dose, 3 h later and on coughing. Heart rate, respiratory rate, and blood pressure were recorded before the drug dose and 3 h later. Postoperative nausea or vomiting (PONV), temperature, and modified Glasgow Coma Scale readings were recorded. The above readings were obtained for 6 doses (up to 48 h after extubation).

Statistics:

t-test, Pearson Chi-square test, Fisher exact test, and Mantel–Haenszel test were used for statistics.

Results:

Tapentadol group patients had significantly better analgesia 3 h after the drug and “on coughing” than tramadol group. The difference in their effects on blood creatinine levels, temperature, hemodynamics, oxygen saturation, and respiratory rate were not clinically significant. Tapentadol produced lesser drowsiness and lesser vomiting than tramadol.

Conclusions:

Tapentadol, due to its norepinephrine reuptake inhibition properties, in addition to mu agonist, is a better analgesic than tramadol and has lesser PONV.

Pain management in dermatologic procedures: before and after

BACKGROUND

Periprocedural analgesic therapy is an often overlooked, but critical component of ensuring adequate surgical patient care and overall satisfaction with surgical outcomes. Adequate pain management requires thorough assessment of pain and complete knowledge and understanding of the various therapeutic agents available.

OBJECTIVES

To further the knowledge and understanding of current strategies in pain management.

METHODS

A literature review was conducted through PubMed to define current pain assessment and management strategies.

RESULTS AND CONCLUSIONS

Appropriate pain assessment leads to the selection of optimal pharmacologic options for pain control in the acute postoperative setting.

Potentiation of local anesthetic activity of neosaxitoxin with bupivacaine or epinephrine: development of a long-acting pain blocker

Local anesthetics effectively block and relieve pain, but with a relatively short duration of action, limiting its analgesic effectiveness. Therefore, a long-acting local anesthetic would improve the management of pain, but no such agent is yet available for clinical use. The aim of this study is to evaluate the potentiation of the anesthetic effect of neosaxitoxin, with bupivacaine or epinephrine in a randomized double-blind clinical trial. Ten healthy males were subcutaneously injected into the left and right forearms with a randomized pair of the following treatments: (i) bupivacaine (5 mg); (ii) neosaxitoxin (10 microg); (iii) neosaxitoxin (10 microg) plus bupivacaine (5 mg), and (iv) neosaxitoxin (10 microg) plus epinephrine (1:100.000), but all participant received all four formulations (in 2 ml; s.c.), with 1 month elapsing between the two round of experiments. A validated sensory and pain paradigm was used for evaluating the effect of the treatment 0-72 h after the injections, measuring sensory, pain, and mechanical touch perception threshold. The duration of the effect produced by combined treatments was longer than that by the single drugs. In conclusion, bupivacaine and epinephrine potentiate the local anesthetic effect of neosaxitoxin in humans when co-injected subcutaneously. The present results support the idea that neosaxitoxin is a new long-acting local pain blocker, with highly potential clinical use.

Pharmacotherapy for acute pain: implications for practice

Effective treatment of perioperative acute pain requires that information about the patient's goals for pain relief, previous history with analgesics, and type of surgical procedure is used to guide decisions about analgesic regimens. Analgesics are selected based on the location of surgery, degree of anticipated pain, and patient characteristics (such as comorbidities), and routes of administration and dosing schedules are determined to maximize the effectiveness and safety of analgesia while minimizing the potential for adverse events. Pain management therapy is then extended into the postsurgical phase of recovery. To accomplish this, nurses must have a thorough understanding of the pharmacology of analgesics. This article provides useful information for commonly used analgesics, primarily nonsteroidal antiinflammatory drugs (NSAIDs), opioids, and local anesthetics for control of acute postoperative pain.

Pharmacotherapy for acute pain: implications for practice

Effective treatment of perioperative acute pain requires that information about the patient's goals for pain relief, previous history with analgesics, and type of surgical procedure is used to guide decisions about analgesic regimens. Analgesics are selected based on the location of surgery, degree of anticipated pain, and patient characteristics such as comorbidities, and routes of administration and dosing schedules are determined to maximize the effectiveness and safety of analgesia, while minimizing the potential for adverse events. Pain management therapy is then extended into the postsurgical phase of recovery. To accomplish this, nurses must have a thorough understanding of the pharmacology of analgesics. This article provides useful information for commonly used analgesics, primarily nonsteroidal antiinflammatory drugs (NSAIDs), opioids, and local anesthetics for control of acute postoperative pain.