Fetal heart rate monitoring in nonobstetric surgery: a systematic review of the evidence.

OBJECTIVE: Concern for fetal well-being during maternal nonobstetric surgery may result in obstetricians and other maternity care providers being asked to perform intraoperative fetal heart rate (FHR) monitoring. We systematically reviewed the evidence regarding the use of FHR monitoring during nonobstetric surgery after potential fetal viability (>22 weeks gestational age), and examined the FHR patterns and outcomes reported. DATA SOURCES: A systematic review of the evidence was performed. Sources included databases (MEDLINE, EMBASE, Cochrane, and CENTRAL), hand searching, guidelines, conference proceedings, and literature reviews. Online searching was performed to include literature published from 1966 to May 2019. STUDY ELIGIBILITY CRITERIA: All studies reviewing care of pregnant women undergoing nonobstetric surgery where FHR monitoring was performed intraoperatively. Data were extracted from appropriate full-text articles using a data abstraction form. STUDY APPRAISAL AND SYNTHESIS: Case reports and case series only were identified. A total of 74 cases were reviewed, encompassing maternal general surgery (n = 41, cardiovascular surgery (n = 13) and neurosurgery/orthopedics (n = 20). Median gestational age at time of maternal surgery was 30 weeks (range, 22-36 weeks). In 41 cases, findings of FHR monitoring were not reported. Abnormal tracings were observed in 29 cases, as either reduced variability (n = 13) or fetal bradycardia (n = 17). All but 3 bradycardias reported occurred during maternal cardiac surgery involving aortic clamping and cardiopulmonary bypass. In 1 case, FHR monitoring was not possible because of a surgical pneumoperitoneum; there was 1 fetal tachycardia associated with maternal pyrexia, and three cases in which FHR monitoring was deemed stable or normal. Three preterm infants were delivered simultaneously at the time of general surgery as a result of FHR abnormalities (at 30, 33, and 34 weeks respectively), 2 as a result of fetal bradycardia and 1 because of protracted reduced variablity. CONCLUSION: The evidence for intraoperative fetal monitoring is based on case reports and cases series. Maternal cardiac surgery involving cardiopulmonary bypass commonly results in fetal bradycardia, which may be challenging to interpret. Obstetricians should be aware of FHR pattern changes in response to anesthesia and surgery that do not justify iatrogenic preterm cesarean delivery.

Intravenous lidocaine for the treatment of background or procedural burn pain.

BACKGROUND: This is an update of the review on "Lidocaine for pain relief in burn injured patients" first published in Issue 3, 2007, and first updated in 2012. Pain is a major issue for people with many different types of wounds, in particular those people with burn injuries. Prompt, aggressive use of opioid analgesics such as morphine has been suggested as critical to avert the cycle of pain and anxiety, but adverse effects are encountered. It has been proposed that newer agents such as lidocaine could be effective in reducing pain and alleviating the escalating opioid dosage requirements in people with burn injury. OBJECTIVES: To assess the safety and effectiveness of intravenous lidocaine as a means of pain relief versus no therapy, placebo, other drugs, or a combination of these therapies in people with burn injury. SEARCH METHODS: For this third update, we searched the Cochrane Central Register of Controlled Trials (Issue 11, 2013), and Ovid MEDLINE, MEDLINE in Process and Ovid EMBASE (up to December 2013). SELECTION CRITERIA: We included randomised controlled trials (RCTs) and controlled clinical trials (CCTs), published and unpublished, which assessed the efficacy of intravenous lidocaine in varying doses as a single-agent therapy with no therapy, placebo, other analgesics (such as opioids), lidocaine plus another drug, or a combination of these therapies as a means of pain relief in people with burn injury. DATA COLLECTION AND ANALYSIS: Two review authors independently abstracted data and assessed the risk of bias of the studies identified. MAIN RESULTS: In this 2014 update, we found no new studies. The one small randomised double-blind placebo-controlled cross-over trial found in 2012, which included only 45 participants and compared intravenous lidocaine against placebo as a means of pain relief in people with burns still remains central to this review. We assessed this study as being at a high risk of bias due to its small size (fewer than 50 participants per treatment arm). Subjective pain ratings, as measured by the verbal rating scale, increased during procedures for both treatment arms; however, the increase was less in the lidocaine treatment group. There were no significant clinical or statistical differences regarding the effects of lidocaine and placebo on opioid requests and consumption, anxiety or level of satisfaction during a wound care procedure, but the small included study provided insufficient data to draw any conclusions. AUTHORS' CONCLUSIONS: As current clinical evidence is based on only one RCT as well as case series and reports, intravenous lidocaine must be considered a pharmacological agent under investigation in burns care, the effectiveness of which is yet to be determined with further well-designed and conducted clinical trials.

Intravenous lidocaine for the treatment of background or procedural burn pain.

BACKGROUND: This is an update of the review on 'Lidocaine for pain relief in burn injured patients' first published in Issue 3, 2007. Pain is a major issue for patients suffering from many different types of wounds, in particular those with burn injuries. Prompt, aggressive use of opioid analgesics such as morphine has been suggested as critical to avert the cycle of pain and anxiety, but side effects are encountered. It is proposed that newer agents such as lidocaine could be effective in reducing pain and alleviating the escalating opioid dosage requirements in patients with burn injury. OBJECTIVES: To assess the safety and effectiveness of intravenous lidocaine as a means of pain relief versus no therapy, placebo, other drugs or two or more of the above therapies in combination in patients exposed to burn injury. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library 2011, Issue 2), MEDLINE (1966 to April 2011 week 4) and EMBASE (1980 to 2011 week 17). SELECTION CRITERIA: We included randomised controlled trials (RCTs) and controlled clinical trials (CCTs), published and unpublished, which assessed the efficacy of intravenous lidocaine in varying doses as a single-agent therapy with no therapy, placebo, other analgesics such as opioids, lidocaine plus another drug, or two or more of the above therapies as a means of pain relief in patients exposed to burn injury. DATA COLLECTION AND ANALYSIS: Two review authors independently abstracted data and assessed the risk of bias of the studies identified. MAIN RESULTS: This update identified one new randomised, double-blind, placebo-controlled, cross-over trial which included 45 participants and compared intravenous lidocaine against placebo as a means of pain relief in those with burns. Subjective pain ratings as measured by the verbal rating scale increased during procedures for both treatment arms, however, the increase was less for the lidocaine treatment arm. There were no significant clinical or statistical differences regarding the effects of lidocaine and placebo on opioid requests and consumption, anxiety or level of satisfaction during a wound care procedure. AUTHORS' CONCLUSIONS: As current clinical evidence is based on only one single RCT as well as case series and reports, intravenous lidocaine must be considered a pharmacological agent under investigation in burns care, the effectiveness of which is yet to be determined with further well-designed and conducted clinical trials.

A systematic review of ketamine as an analgesic agent in adult burn injuries.

OBJECTIVE: To assess the current literature regarding the effectiveness and side-effect profile of intravenous ketamine as a means of pain relief when compared with placebo or as an adjunct to opioid analgesia in patients exposed to burn injury. DESIGN: Electronic searches of MEDLINE, CINAHL, Embase, and The Cochrane Library databases from 1966 onward were used to identify clinical trials comparing ketamine with placebo in the adult burn population. OUTCOMES MEASURED: Effectiveness and side-effect profile of ketamine as an analgesic agent in burn injuries. RESULTS: Four experimental trials involving 67 patients were identified. Due to heterogeneity of studies, pooling of the results and meta-analysis were not possible. Intravenous ketamine showed some efficacy as an analgesic for burn injuries, with a reduction in secondary hyperalgesia when compared with opioid analgesia alone. Combination therapy of ketamine and morphine resulted in the abolishment of windup pain phenomena. The side-effect profile did not result in the withdrawal of any participants included in the studies' results. CONCLUSIONS: Further well-designed randomized controlled trials conducted in burn-specific populations are warranted, thus enabling the development of a relevant evidence base to support its clinical use.