Analgesic Effects of Intravenous Ketamine during Spinal Anesthesia in Pregnant Women Undergone Caesarean Section; A Randomized Clinical Trial

Multimodal Acute Pain Management in the Parturient with Opioid Use Disorder: A Review

The opioid epidemic in the United States has led to an increasing number of pregnant patients with opioid use disorder (OUD) presenting to obstetric units. Caring for this complex patient population requires an interdisciplinary approach involving obstetricians, anesthesiologists, addiction medicine physicians, psychiatrists, and social workers. The management of acute pain in the parturient with OUD can be challenging due to several factors, including respiratory depression, opioid tolerance, and opioid-induced hyperalgesia. Patients with a history of OUD can present in one of three categories: 1) those with untreated OUD; 2) those who are currently abstinent from opioids; 3) those being treated with medications to prevent withdrawal. A patient-centered, multimodal approach is essential for optimal peripartum pain relief and prevention of adverse maternal and neonatal outcomes. Medications for opioid use disorder (MOUD), previously referred to as medication-assisted therapy (MAT), include opioids like methadone, buprenorphine, and naltrexone. These are prescribed for pregnant patients with OUD, but appropriate dosing and administration of these medications are critical to avoid withdrawal in the mother. Non-opioid analgesics such as acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs) can be used in a stepwise approach, and regional techniques like neuraxial anesthesia and truncal blocks offer opioid-sparing options. Other medications like ketamine, clonidine, dexmedetomidine, nitrous oxide, and gabapentinoids show promise for pain management but require further research. Overall, a comprehensive pain management strategy is essential to ensure the well-being of both the mother and the fetus in pregnant patients with OUD.

Effect of Intravenous Ketamine Infusion on Hemodynamics of Patients Undergoing Cesarean Delivery after Spinal Anaesthesia: A Randomized, Double-Blind, Controlled Trial

Objective

Hypotension is the most frequent side effect of intrathecal anaesthesia, with an incidence of more than 80%. Following neuraxial anaesthesia, perioperative shivering is a serious complication affecting 40-60% of patients undergoing surgery. This study aimed to determine the effectiveness of low-dose ketamine on blood pressure in patients undergoing cesarean delivery after spinal anaesthesia.

Methods

We included 126 female patients undergoing cesarean deliveries, American Society of Anesthesiologists (ASA)-(II and III), and aged 21-40 selected from the outpatient clinics of the anaesthesia department. Patients were randomized to two groups; Group K (63 patients), who received 0.3 mg kg-1 of ketamine IV diluted to 10 mL, followed by an infusion of 0.1 mg kg-1 h-1. Group C (Controlled) (63 patients) received 10 mL of normal saline, followed by an infusion of 0.1 mL kg-1 h-1, which started before spinal anaesthesia.

Results

Compared with the saline group, the average heart rate, blood pressure, and level of sedation were significantly higher in the ketamine group (P < 0.05). The ketamine group reported a significantly lower incidence of shivering (P < 0.01). The ketamine groups exhibited significantly less mild or severe hypotension (P < 0.05). There was no significant difference between the two groups in terms of nystagmus, diplopia, hallucinations, or neonatal outcomes (P > 0.05).

Conclusion

Ketamine decreases the incidence of hypotension and shivering in patients undergoing spinal anaesthesia during cesarean delivery. In addition, it resulted in improved sedation for the mother and prolonged postoperative analgesia without neonatal illness.

The Effect of Intravenous Ketamine After Spinal Anesthesia on the Duration of Postoperative Analgesia and Analgesic Requirement

Background

One of the most unpleasant aspects of surgery for a patient is postoperative discomfort. To treat the pain prophylactically, deliberate action should be taken. Exogenous opioids, such as morphine or fentanyl, have been used as the cornerstone of treatment to date. Opioid use is frequently linked to negative consequences. Ketamine is by far the most adaptable anesthetic medication accessible, possibly in all of medicine. Ketamine’s principal analgesic impact is because of its antagonism to N-methyl-D-aspartate receptors (NMDA) receptors. Ketamine affects pain processing in the central nervous system in this way. Ketamine has proven to be an effective antihyperalgesic, preventing opioid-induced hyperalgesia. Therefore, we investigated the impact of ketamine following spinal anesthesia on the duration of postoperative analgesia and the need for analgesics.

Methods

This was a prospective, randomized, double-blinded study done over a period of two years. A total of 60 patients undergoing elective surgeries under spinal anesthesia were randomized into two groups. After 10 min of spinal anesthesia and achieving the required level of sensory and motor blockade, both groups were given Inj. Midazolam 1 mg intravenously, followed by Inj. Ketamine 0.25 mg/kg, volume made up to 10 mL with normal saline, given intravenously in Group K and Inj. Normal Saline 10 mL was given intravenously in Group N. Hemodynamic monitoring was done intraoperatively, and the postoperative visual analog score (VAS), sedation score, the mean time for the first rescue analgesia, and the total dose of postoperative analgesic required in 24 h were tabulated.

Results

There was no statistical difference between the two groups in terms of age, weight, ASA grade, and duration of surgery. In Group K, the VAS scores were significantly lower and patients were comfortable when compared to Group N ( P-value <.01). The mean time to first rescue analgesia was longer in Group K (6.4 ± 1.69 h) when compared to Group N (2.9 ± 1.01 h), and the total dose of postoperative analgesia (Tramadol) required in 24 h was also significantly less in Group K (143.33 ± 56.83 mg) when compared to Group N (236 ± 49.01 mg). Changes in hemodynamic parameters (heart rate and mean arterial pressure (MAP) were statistically and clinically not significant in both the intraoperative and postoperative periods in both the groups.

Conclusion

Patients in Group K were more comfortable, had a longer duration of postoperative analgesia, and required less dose of rescue analgesia in the postoperative period. Ketamine is a safe drug that is readily available, and it decreases the use of opioids and opioid-related side effects. Therefore, ketamine can serve effectively as an adjunctive analgesic drug.

Analgesic effects of intravenous ketamine after spinal anaesthesia for non-elective caesarean delivery: a randomised controlled trial

OBJECTIVES

This study aimed to determine if low dose intravenous ketamine is effective in reducing opioid use and pain after non-elective caesarean delivery.

DESIGN

Prospective, randomised, double-blind.

SETTING

Tertiary hospital, Bisheshwar Prasad Koirala Institute of Health Sciences, Dharan, Nepal PARTICIPANTS: 80 patients undergoing non-elective caesarean section with spinal anaesthesia.

INTERVENTIONS

Patients were allocated in 1:1 ratio to receive either intravenous ketamine 0.25 mg/kg or normal saline before the skin incision.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was the total amount of morphine equivalents needed up to postoperative 24 hours. Secondary outcome measures were postoperative pain scores, time to the first perception of pain, maternal adverse effects (nausea, vomiting, hypotension, shivering, diplopia, nystagmus, hallucination) and neonatal Apgar score at 1 and 5 min, neonatal respiratory depression and neonatal intensive-care referral.

RESULTS

The median (range) cumulative morphine consumption during the first 24 hours of surgery was 0 (0-4.67) mg in ketamine group and 1 (0-6) mg in saline group (p=0.003). The median (range) time to the first perception of pain was 6 (1-12) hours and 2 (0.5-6) hours in ketamine and saline group, respectively (p<0.001). A significant reduction in postoperative pain scores was observed only at 2 hours and 6 hours in the ketamine group compared with placebo group (p<0.05). Maternal adverse effects and neonatal outcomes were comparable between the two groups.

CONCLUSIONS

Intravenous administration of low dose ketamine before surgical incision significantly reduced the opioid requirement in the first 24 hours in patients undergoing non-elective caesarean delivery.

TRIAL REGISTRATION NUMBER

NCT03450499.

Assessments of Heart Rate and Sympathetic and Parasympathetic Nervous Activities of Normal Mouse Fetuses at Different Stages of Fetal Development Using Fetal Electrocardiography

Heart rate is controlled by the activity of the autonomic nervous system: the sympathetic and parasympathetic nervous systems increase and suppress heart rate, respectively. To evaluate the activity of the autonomic nervous system, it is possible to determine heart rate variability using electrocardiography (ECG). During the fetal period, the heart and autonomic nerves develop in coordination; however, physiological changes, including autonomic nervous activities that occur during the fetal stage, remain largely unknown. Therefore, in this study, we measured ECG signals of mouse fetuses using our established method to evaluate the development of heart rate and autonomic nervous activity at different fetal developmental stages. We found that heart rate was significantly increased in fetal mice at embryonic day (E) 18.5 compared with that at E13.5, E15.5, and E17.5, indicating that fetal heart rate increases only at the stage immediately prior to birth. Interestingly, fetal parasympathetic nervous activity was reduced at E17.5 and E18.5 compared with that at E13.5, whereas fetal sympathetic nervous activity remained unchanged, at least from E13.5 to E18.5. These results indicate that parasympathetic activity rather than sympathetic activity affects fetal heart rate and that the decrease in parasympathetic activity toward the end of pregnancy could result in the observed increase in fetal heart rate.

The use of adjunct anesthetic medication with regional anesthesia and rates of general anesthesia for 1867 cesarean deliveries from 2014 to 2018 in a community hospital

The number of cesarean deliveries performed with a general anesthetic decreased when regional anesthesia for cesarean delivery was reported to be associated with lower maternal mortality. Anesthetic adjunct administration for cesarean deliveries performed with regional anesthesia is typically not reported alongside general anesthesia rates for cesarean delivery. This retrospective study analyzed rates of general anesthesia and systemic anesthetic adjunct administration for cesarean deliveries performed under regional anesthesia at a community hospital from 2014 to 2018. We used the hospital electronic medical record system to collect data on cesarean deliveries during the study period. A total of 1867 cesarean deliveries were performed, corresponding to a cesarean delivery rate of 30.4%. Of the subjects, 104 (5.6%) received general anesthesia and 333 (17.8%) received regional anesthesia with at least one systemic anesthetic adjunct. These adjuncts included a variety of intravenous agents-midazolam (1.7%), fentanyl (5.2%), morphine (6.6%), propofol (7.9%), and ketamine (1.7%)-as well as inhaled nitrous oxide (1.4%) and sevoflurane (0.1%). These data on anesthetic adjunct administration with regional anesthesia provide clinical context for the rates of general anesthesia reported for cesarean delivery.

Effect of Low-Dose Intravenous Ketamine on Prevention of Headache After Spinal Anesthesia in Patients Undergoing Elective Cesarean Section: A Double-Blind Clinical Trial Study

Background

Spinal anesthesia is the most commonly used method for elective cesarean section, which is a popular technique due to its simplicity, reliability, and speed to achieve adequate anesthesia. Headache following dura perforation is the most important delayed complication following spinal and epidural anesthesia.

Objectives

To evaluate the impact of low-dose intravenous ketamine in patients undergoing cesarean section under spinal anesthesia on the prevention of dura perforation headache (PDPH).

Methods

This clinical trial study was performed on 64 pregnant women undergoing cesarean section at Vali-e-Asr Hospital. The patients were divided into two groups. In the case group, 0.15 mg/kg body weight ketamine was injected intravenously and in the control group, normal saline was used as the placebo. The incidence of headache and its severity at one, 4, 12, and 24 hours postoperatively, nausea and its severity were also measured and compared. Independent t-test, Mann-Whitney U and chi-square tests were used. A P value < 0.05 was considered statistically significant.

Results

The data revealed that low dose intravenous ketamine significantly decreased patients’ headaches (P = 0.001), the sensation of pruritus (P = 0.009), and the need for analgesic (P = 0.001). Furthermore, the sensation of postoperative nausea was less in the case group. The patients in the case and control groups had no significant difference in terms of hypertension or bradycardia (P = 0.717 and 0.939, respectively).

Conclusions

The injection of ketamine as a premedication in the cesarean section can reduce the severity of postoperative headache in mothers. Therefore, it is recommended to use ketamine as an anti-headache drug in pregnant women.

Anesthesia considerations and post-operative pain management in pregnant women with chronic opioid use

The prevalence of opioid use disorder in pregnancy has escalated markedly in recent years. Chronic opioid use during pregnancy poses several challenges for providing adequate analgesia and anesthesia in the peripartum period. These challenges include the potential for withdrawal, opioid tolerance and opioid-induced hyperalgesia. Here we discuss alterations in analgesic pharmacokinetics and pharmacodynamics that are associated with chronic opioid use. In addition, when treating pain in patients with opioid use disorder it is important to distinguish between different subgroups. In this review, we will discuss practical management strategies for parturients with (1) untreated opioid use disorder, (2) parturients on medication-assisted treatment (methadone, buprenorphine) and (3) patients recovering from opioid use disorder that are currently abstinent. Finally, we offer an overview of non-opioid strategies that may be utilized as part of a multimodal approach to providing optimal analgesia in this patient population.

Comparison of Dexmedetomidine and Fentanyl as an Adjuvant to Lidocaine 5% for Spinal Anesthesia in Women Candidate for Elective Caesarean

AIM

This study aimed to compare the effect of Dexmedetomidine and fentanyl as an adjuvant to lidocaine 5% in spinal anaesthesia to increase post-operative analgesia among women candidates for elective caesarean.

METHODS

Eighty-four pregnant women candidates for caesarian were randomly divided into fentanyl and Dexmedetomidine groups. In the first group, 25 μg fentanyl was added to lidocaine 5% while in the second group, 0.5 μg per kilogram Dexmedetomidine was added to lidocaine 5%. After the operation, a pain score of the patients in recovery and within 4, 12 and 24 hours after the operation, the average length of analgesia and the average amount of the analgesics taken within 24 hours and after the operation were recorded.

RESULTS

The average length of postoperative anaesthesia and the average amount of the drug taken within the first 24 hours after the operation in fentanyl group was more than the Dexmedetomidine group (P = 0.01). Shivering in Dexmedetomidine group was more common than what was observed in the fentanyl group (P = 0.001). Higher rates of nausea-vomiting were observed in the fentanyl group (P = 0.001).

CONCLUSIONS

Fentanyl results in a longer period of postoperative analgesia and less consumption of drugs after the operation. Fentanyl is recommended in caesarian.

Association of hemodynamics during caesarean section, outcomes after caesarean section and hormone changes with different anesthesia in pregnant women with severe pulmonary arterial hypertension

In the present study we aimed to analyze the effects of different anesthesia methods on the hemodynamics of caesarean section, outcomes after caesarean section and hormone changes in pregnancy complicated with severe pulmonary arterial hypertension (PAH). A total of 75 pregnancy complicated with severe PAH that were treated in Jining First People's Hospital from January 2016 to January 2017 were selected. Three groups were set according to the anesthesia methods, including the subarachnoid combined epidural anesthesia group (group I, n=25), the epidural anesthesia group (group II, n=25) and the general anesthesia group (group III, n=25). Effects on the outcomes of caesarean section of pregnancy complicated with PAH were observed. Sex hormone levels before and 24, 48 and 72 h after the operation were measured. There were remarkable changes in the postoperative hemodynamics compared with those before anesthesia, but changes in groups I and II were significantly smaller than those in group III (P<0.05). No significant differences in maternal mortality rate, neonatal mortality rate and neonatal asphyxia rate among the three groups were found (P>0.05). Time of postoperative mechanical ventilation, ICU residence and hospitalization in groups I and II were shorter than those in group III, the differences were statistically significant (P<0.05). Postoperative levels of sex hormones, including estradiol (E2), human chorionic gonadotrophin (HCG), prolactin (PRL) and plasma total testosterone (TT) decreased, while postoperative levels of sex hormones follicle stimulating hormone (FSH), luteinizing hormone (LH) and progestogen increased, and differences in the decreased E2 and TT at each time-point were statistically significant (P<0.05). In conclusion, there is no remarkable difference in the effects of three anesthesia methods on pregnancy outcomes. However, compared with general anesthesia, intravertebral anesthesia achieve shorter time of postoperative mechanical ventilation, ICU residence and hospitalization in pregnancy complicated with severe PAH, which is preferred in pregnancy without contraindication of the anesthesia.

Intravenous ketamine during spinal and general anaesthesia for caesarean section: systematic review and meta-analysis

BACKGROUND

Intravenous ketamine has been used during general and regional anaesthesia for caesarean section. No systematic review and meta-analysis on the desired effects and adverse effects of ketamine administration during caesarean section have yet been performed.

METHODS

After a systematic literature search a meta-analysis was conducted with the random effects model. Weighted mean difference (WMD) or risk ratio and 95% confidence intervals (CIs) were computed.

RESULTS

Twelve randomised controlled double-blind trials comprising 953 patients were included: seven studies reported on spinal anaesthesia and five on general anaesthesia. Significant differences in the aforementioned outcome variables were found only in the spinal anaesthesia studies. In the spinal anaesthesia studies the time to the first analgesic request was significantly longer in ketamine-treated women, the WMD was 49.36 min (95% CI 43.31-55.41); visual analogue scale pain scores at rest 2 h after surgery were significantly lower. No differences were observed for maternal nausea, vomiting, pruritus, and psychomimetic effects. Only few data were found for neonatal outcomes.

CONCLUSIONS

We conclude that ketamine enhances post-operative analgesia after caesarean section under spinal anaesthesia. There is a paucity of data for several maternal adverse effects as well as for neonatal well-being. Further studies are needed for general anaesthesia.

The effect of low-dose intravenous ketamine on postoperative pain following cesarean section with spinal anesthesia: a randomized clinical trial

OBJECTIVES

Low-dose ketamine has been considered a good substitute for opioids for controlling postoperative pain. The purpose of this study was to determine the effect of low-dose intravenous ketamine following cesarean section with spinal anesthesia on postoperative pain and its potential complications.

METHODS

One hundred and sixty pregnant women volunteered to participate in this randomized controlled trial. Participants were randomly divided into two groups (n=80 for each group). Five minutes after delivery, the experimental group received 0.25mg/kg ketamine while the control group received the same amount of normal saline.

RESULTS

There was a significant difference between the two groups in the severity of pain at one, two, six, and 12 hours following surgery. Postoperative pain was significantly less severe in the experimental group. Compared to the control group, the experimental group felt pain less frequently and therefore asked for analgesics less often. On average, the number of doses of analgesics used for the participants in the experimental group was significantly less than the number of doses used for the control group. Analgesic side effects (including nausea, itching, and headache) were not significantly different between the two groups. However, vomiting was significantly more prevalent in the control group and hallucination was more common in the experimental group.

CONCLUSION

We conclude that administration of low doses of ketamine after spinal anesthesia reduces the need for analgesics and has fewer side effects than using opioids. Further studies are required to determine the proper dose of ketamine which offers maximum analgesic effect. Furthermore, administration of low-dose ketamine in combination with other medications in order to minimize its side effects warrants further investigation.

Effect of intravenous patient controlled ketamine analgesiaon postoperative pain in opium abusers

Background:

Acutepostoperative pain is among the worst experience that patient scan undergo, and many analgesics have been used to suppress it; especially in chronic opium abusers. Ketamine is an N-methyl-D-aspartate antagonist analgesic, having both anesthetic and analgesic properties, which are not affected to the same extent in chronic opium abusers.

Objectives:

In this study, we assessed the analgesic effects of ketamine added to morphine as a patient-controlled analgesia method for acute pain management, compared with a placebo, inchronic maleopium abusers.

Patients and Methods:

After institutional review board approval for ethical considerations, a randomized double-blinded placebo controlled clinical trial was conducted. A total of 140 male patients aged 18-65 years, undergoing orthopedic surgery, were entered into the study after matching inclusion and exclusion criteria. All patients received the same anesthesia method; while the first group received ketamine (1mg/mL) and morphine (0.5 mg/mL) as a patient-controlled analgesia (70 patients), the second group received morphine (0.5 mg/mL) plus normal saline (70 patients). P value less than 0.05 was considered statistically significant.

Results:

The ketamine and morphine group of patients experienced less postoperative pain and required less postoperative rescue analgesia. However, the unwanted postoperative side effects were nearly the same; although increased levels of postoperative nausea and vomiting were observed in the ketamine and morphine group

Conclusions:

This study demonstrated improved analgesic effects after using intravenous patient controlled analgesia with ketamine on postoperative pain in opium abusers.