A retrospective assessment of the incidence of respiratory depression after neuraxial morphine administration for postcesarean delivery analgesia

Routine External Iliac Artery Cannulation in Robotic Cardiac Surgery: Role of the Corona "Vitae" in Distal Limb Perfusion

OBJECTIVE

Femoral artery cannulation is the most commonly used approach for cardiopulmonary bypass (CPB) in robotic cardiac procedures. However, without adding a distal perfusion cannula, leg ischemia can occur in up to 11.5% of patients. There is a well-described 2 to 4 mm size arterial branch that originates from the medial side of the external iliac artery or inferior epigastric artery, immediately above the inguinal ligament, and connects to the obturator artery. Therefore, it was historically named the corona mortis, which means "crown of death" in Latin. When peripheral cannulation is performed above this branch in the external iliac artery, we consider it a corona "vitae" because of its role as a limb-saving collateral. We report herein our standard technique of peripheral cannulation without the need of a distal perfusion cannula and preventing limb ischemia.

METHODS

We included all patients who underwent robotic cardiac surgery with peripheral cannulation over a 16-month period at our institution. We cannulated just above the level of the inguinal ligament through a 2 to 3 cm transverse skin incision. The incidence of limb ischemia and vascular complications was recorded and analyzed.

RESULTS

During the study period, 133 patients underwent robotic cardiac procedures with peripheral "external iliac" CPB. The size of the cannula was 21F or larger in 73% and 23F in 54% of the patients. No leg ischemia or femoral artery complications requiring additional intervention occurred.

CONCLUSIONS

External iliac cannulation can be successfully performed in robot-assisted cardiac surgery using relatively large cannulas without the need of a distal limb perfusion catheter, with good results. In our view, given the importance of the corona mortis ("crown of death" in Latin) in perfusing the limb during CPB, we propose a new name for this artery in robotic cardiac surgery, namely, the corona vitae ("crown of life" in Latin).

Effects of Intrathecal Morphine Administration in Patients Undergoing Primary Total Hip Arthroplasty Under Spinal Anesthesia With Quadratus Lumborum Block for Postoperative Analgesia

Introduction Quadratus lumborum (QL) block has previously been shown to provide improved analgesia in patients undergoing primary total hip arthroplasty (THA) under spinal anesthesia when compared to spinal anesthesia alone. Additionally, recent studies have shown the addition of intrathecal morphine (ITM) to provide superior postoperative analgesia in patients undergoing various surgical interventions including total knee arthroplasty under spinal anesthesia with peripheral nerve blockade. At this time, however, there has not been a study evaluating the effects of intrathecal morphine in patients undergoing THA under spinal anesthesia with QL block. This study aims to assess if the addition of intrathecal morphine can provide adequate or even superior postoperative analgesia in patients undergoing primary THA. Methods This retrospective study included 26 patients in the spinal/QL block/intrathecal morphine (SA+QLB+ITM) group, 31 patients in the spinal/QL block group (SA+QLB), and 28 patients in the spinal only (SA or control) group. Twenty-six patients undergoing primary THA under a combination of spinal anesthesia and peripheral nerve blockade (quadratus lumborum block) were given a dose of 100 mcg of intrathecal morphine. Various parameters were evaluated including Post-Anesthesia Care Unit (PACU) and 24-hour visual analog scale (VAS) scores, time to first opioid use, 24- and 48-hour total opioid use as oral morphine equivalents (OME), 24-hour ambulation distance, and time from block placement to hospital discharge. The results were analyzed and compared to patients undergoing primary THA under spinal anesthesia with QL block (no intrathecal morphine) and compared to a control group of patients undergoing primary THA under spinal anesthesia only. Results The study analysis included 26 patients in the SA+QLB+ITM group, 31 patients in the SA+QLB group, and 28 patients in the SA (control) group. When compared with the control group, the SA+QLB+ITM had lower 24-hour total opioid usage (mean difference 20.80 OME, CI 6.454 to 35.15, p-value 0.0025), longer time to 1st opioid use (mean difference -20.51 hours later, p-value .0052), lower 24-hr VAS (difference 2.421, p-value 0.0012, CI 0.8559 to 3.987), and faster time to discharge (16.00 hr earlier, p-value 0.0459). When compared to the SA+QLB group, the SA+QLB+ITM group only showed a statistically significant difference in faster time to discharge (19.46 hr earlier, p-value 0.0068). However, while there was no statistically significant difference in time to 1st opioid use between the control and SA+QLB group, the difference did become significant when comparing the control to the SA+QLB+ITM group (mean difference -20.51 hours later (p-value .0052). There was no significant difference in either of the three groups in ambulation distance at 24 hours, PACU VAS, or 48-hour total opioid use. Conclusion Our study concludes that the addition of 100 mcg ITM for total hip arthroplasty under spinal anesthesia improved postoperative analgesia compared to the control group. Also, the ITM group did better with respect to delay in first opioid use and decreased hospital stay compared to the control and block-only groups. Our study warrants no more concerns of PONV, pruritus, or respiratory depression with this dose of ITM and requires standard postoperative care.

Comparison of the Efficacies of Three Different Intrathecal Doses of Morphine in Achieving Postcesarean Delivery Analgesia

PURPOSE

The objective of this study is to compare the efficacies of 3 different intrathecal doses (80, 120, and 160 mcg) of morphine in achieving postcesarean delivery analgesia and the severity of the side effects thereof.

DESIGN

A prospective, randomized, double-blind study.

METHODS

A total of 150 pregnant women between the ages of 18 and 40, with a gestational week >36, who were planned to have elective cesarean section were included in the study. Patients were randomized into 3 groups based on the dosages of intrathecal doses of morphine (80, 120, and 160 mcg) they will receive in addition to 10 mg 0.5% hyperbaric bupivacaine and 20 mcg fentanyl. Intravenous (IV) patient-controlled analgesia (PCA) prepared with fentanyl was administered to each patient after the surgery. Postoperative 24-hour total IV PCA-fentanyl consumption was recorded. The patients were evaluated for side effects such as pain, nausea-vomiting, pruritus, sedation score, and respiratory depression after the surgery.

FINDINGS

PCA-fentanyl consumption was significantly higher in Group 1 compared to Group 2 and 3 (P = .047). There was no significant differences between the groups in terms of nausea-vomiting scores. The pruritus scores were significantly higher in Group 3 compared to Group 1 (P = .020). The pruritus scores were significantly higher in all groups at the postoperative 8th-hour (P = .013). Respiratory depression, which would require treatment, was not observed in any patient.

CONCLUSIONS

Based on the study findings, it was concluded that 120 mcg intrathecal morphine provides adequate analgesia with minimal side effects in cesarean sections.

Intrathecal Morphine versus Morphine-Dexmedetomidine Combination for Postoperative Pain Control After Total Knee Replacement: A Randomized Controlled Trial

Objective

This prospective study aimed to compare the analgesic efficacy and adverse effects of intrathecal morphine, dexmedetomidine, and a combination of both in patients undergoing total knee replacement (TKR).

Patients and Methods

This randomized prospective study was carried out in Tanta university hospital in orthopedic surgery for 6 months on 105 adult patients with American Society of Anesthesiologists Physical Status Class II and III, aged > 50 years, and scheduled for total knee replacement surgery randomly allocated into morphine group received 0.5% heavy bupivacaine plus 0.1 mg of morphine, morphine/ dexmedetomidine group, received 0.5% heavy bupivacaine plus 0.1 mg of morphine and 5 mcg of dexmedetomidine and dexmedetomidine group received 0.5% heavy bupivacaine plus 5 mcg of dexmedetomidine. The time of the first required analgesia, postoperative pain severity, the total dose of morphine, postoperative complication, and the patient's level of sedation were recorded.

Results

About half of the patients in the dexmedetomidine group requested first rescue analgesia 6 hours after the operation, significantly shorter than the other two groups. On the other hand, the other two groups show no significant difference between them regarding the first required analgesia. At rest, the dexmedetomidine group have significantly higher VAS with a significant increase in patients who required morphine as rescue analgesia than the other two groups. While at movement, patients in the dexmedetomidine group felt pain at 4 hrs postoperatively with significantly higher VAS than the other two groups. At the same time, the sedation score was significantly lower in the dexmedetomidine group than in the other two groups. 22.2% of cases in the morphine group developed nausea and vomiting with a significant difference between the three groups.

Conclusion

Despite the absence of substantial side effects, our findings did not suggest enhanced analgesia with the combination of intrathecal morphine and dexmedetomidine.

Intrathecal Morphine Use Improves Postoperative Analgesia and Reduces Opioid Consumption in Patients Undergoing Total Knee Arthroplasty Under Spinal Anesthesia: A Retrospective Study

Background Intrathecal morphine (ITM) provides effective postoperative analgesia for patients undergoing total knee arthroplasty (TKA) under spinal anesthesia (SA). The management of pain in patients undergoing TKA has remained a challenge for anesthesiologists, as no single regional anesthesia technique is adequate with regard to balancing effective analgesia with minimal side effects. Severe postoperative pain following TKA has been shown to negatively impact patient outcomes and mortality. This study is aimed to describe the effect of intrathecal morphine in patients undergoing total knee arthroplasty. Methods This was a retrospective, descriptive, and single-center study conducted on patients undergoing total knee arthroplasty from June 1, 2022, to June 1, 2023. The sample size consisted of 50 patients who were 18 years and older, American Society of Anesthesiology (ASA) class 1-3, and patients who had received either 150 mcg (experimental) or no ITM dose under spinal anesthesia. Oral morphine requirement (OME) and visual analog pain scale (VAS) were used to assess pain in the first 24 hours after surgery. Results The experimental group had significantly lower OME usage in the post-anesthesia care unit (PACU) (p < 0.001) and at six hours (p = 0.040) postoperatively. At 12 hours and 24 hours postoperatively, the two groups had similar OME use (p > 0.20, for both). The experimental group had significantly less total OME use over the first 24-hour postoperative period. The experimental group had significantly lower pain scores in the PACU (p < 0.001) and at six hours postop (p = 0.002); there were no significant differences between groups at 12- and 24-hours postop. The ambulation distance was clinically significant and better in the ITM group but was not statistically significant (p = 0.080). There was no difference between groups in the incidence of postoperative nausea and vomiting (PONV). Conclusion The careful use of ITM with the optimal dose offers an effective addition to regional anesthesia for improved analgesia with minimal side effects. The 150 mcg ITM dose provided good analgesic effects with longer duration and was not associated with respiratory depression.

Respiratory depression following cesarean section with single-shot spinal with 100 μg morphine

PURPOSE

Little evidence is available regarding bradypnea measured using continuous monitoring following cesarean section. We aimed to evaluate the rate of cumulative bradypnea time (total bradypnea time/total monitoring time) and its related factors in these parturients.

METHODS

This prospective observational study included women undergoing cesarean section under single-shot spinal anesthesia of 0.1 mg morphine. The Berlin Questionnaire was used to screen for sleep apnea syndrome preoperatively. Respiratory rate and oxygen saturation (SpO₂) were monitored continuously using an adhesive acoustic respiration sensor and pulse oximeter, respectively, at least 6 h after cesarean section. Bradypnea was defined as a respiratory rate < 8 breaths/min lasting at least 25 s (sustained bradypnea) or at least 15 s (immediate bradypnea). Hypoxemia was defined as SpO₂ < 92% lasting at least 25 s (sustained hypoxemia) or at least 15 s (immediate hypoxemia). Multiple regression analysis was applied to assess factors related to the rate of cumulative sustained bradypnea.

RESULTS

Of 159 patients, the Berlin Questionnaire was positive in 16.3%, and 77 (48.4%) experienced sustained bradypnea. The median rate of cumulative sustained bradypnea time was 0.70% (interquartile range 0.35-1.45%) without any related factors. The incidence of immediate bradypnea and sustained and immediate hypoxemia were 58.5%, 24.5%, and 37.7%, respectively. However, none of the factors were significant.

CONCLUSION

After cesarean section was performed with 0.1 mg intrathecal morphine, respiratory depression events were commonly observed. However, the rate of cumulative bradypnea time was very low and there were no related factors.

Comparison of low-dose morphine intrathecal analgesia and sufentanil PCIA in elderly patients with hip fracture undergoing single spinal anesthesia - a randomized clinical trial

Background

The complications of postoperative pain, such as hypertension, hypermetabolism, irritability, and postoperative cognitive dysfunction, significantly affect the postoperative rehabilitation of elderly patients. Intrathecal morphine prolongs analgesia after surgery, but has been implicated in nausea and vomiting, pruritus, postoperative respiratory depression, or apneic episodes. The present study explored the effect and safety of low-dose morphine used adjunctively with bupivacaine during single spinal anesthesia or sufentanil patient-controlled intravenous analgesia (PCIA) in elderly patients with hip fracture surgery. Since elderly patients often need anticoagulant therapy in the early postoperative period, single spinal anesthesia was involved in completing the operation in this study.

Methods

Eighty elderly patients aged 70–85 years who underwent elective hip fracture surgery with single spinal anesthesia were divided into two groups, 12.5 mg of 0.5% hyperbaric bupivacaine with 100 µg of morphine (morphine group, group M) and 12.5 mg of 0.5% hyperbaric bupivacaine with 100 µg of sufentanil PCIA (sufentanil group, group S). The analgesia scores using the visual analogue scale (VAS), the Brinell comfort scale (BCS) were evaluated at 6, 12, 24, and 48 h after operation, and adverse reactions were recorded such as nausea and vomiting, pruritus, sedation, respiratory depression, and POD (postoperative delirium) with Delirium Rating Scale-r 98.

Results

Within 24 h after operation, the analgesic and BCS scores of group M were better than those of group S (P < 0.05). Group M had higher frequency of skin pruritus than group S within 24 h, and the difference was statistically significant. The incidence of POD in group M (2 cases) was lower than that in group S (6 cases) (5.71% vs 18.18%) (P < 0.05) with the DRS-r 98 scores. No significant difference was observed in nausea and vomiting between the two groups, and the difference of severe respiratory depression was not found in both groups.

Conclusion

Compared with sufentanil PCIA, low-dose intrathecal morphine has a satisfactory analgesic effect, and little effect on the patient's cognitive function with low medical cost. Under effective respiratory monitoring, it can be used safely and effectively in elderly patients with hip fracture.

Trial registration

Registered with the Chinese Clinical Trial Registry under ChiCTR2100042706. 26/01/2021.

Obstructive sleep apnea in pregnant women

The prevalence of OSA in the low-risk obstetric population is thought to be low; best estimates have been extrapolated from the one available large prospective study and likely range between 3–8%.1 OSA prevalence in high-risk pregnant women such as those with obesity and chronic hypertension is significantly higher as extrapolated from several smaller prospective studies which have reported a prevalence as high as 37% in obese women.2 –6 Despite the high prevalence of OSA in high-risk pregnant women, it remains underdiagnosed due to several factors.

An emerging body of literature suggests that OSA may also have serious implications for the health of mothers and fetuses during and beyond pregnancy, but there is still no data to determine if OSA treatment mitigates these adverse outcomes. In this review, we will examine this body of literature from the perspective of the anesthesiologist: the association between pregnancy and the development or worsening of OSA; OSA as it relates to adverse maternal and fetal outcomes; antepartum and screening considerations for OSA in pregnant women; and recommendations regarding the peripartum management of OSA.

Postoperative Respiratory Compromise following Cesarean Birth: The Impact of Obesity and Systemic Opioids

Objective  The aim of this study was to measure the effect of obesity and systemic opioids on respiratory events within the first 24 hours following cesarean. Methods  Opioid-naive women undergoing cesarean between January 2016 and December 2017 were included in this retrospective cohort study. The primary outcome was the proportion of women experiencing at least one composite respiratory outcome (oxygen saturation less than 95% lasting 30+ seconds or need for respiratory support) within 24 hours of cesarean. The impact of obesity and total systemic opioid dose in 24 hours (measured in morphine milligram equivalents [MMEs]) on the composite respiratory compromise outcome were evaluated. Results  Of 2,230 cesarean births, 790 women had at least one composite respiratory event. Predictors of the composite respiratory outcome included body mass index (BMI) as a continuous variable (odds ratio = 1.063 for every one unit increase in BMI [95% confidence interval (CI): 1.021-1.108], p  = 0.003), and MME (odds ratio = 1.005 [95% CI: 1.002-1.008], p  = 0.003), adjusting for magnesium sulfate use. The interaction between obesity and opioid dose demonstrated an odds ratio of 1.000 (95% CI: 0.999-1.000, p  = 0.030). Conclusion  The proportion of women experiencing respiratory events following cesarean birth increases with the degree of obesity and opioid dose. Key Points Respiratory events increase with obesity.Respiratory events increase with systemic opioid use.Odds ratio of respiratory events is 1.063/unit BMI increase.

Predicting opioid-induced oversedation in hospitalised patients: a multicentre observational study

OBJECTIVES

Opioid-induced respiratory depression (OIRD) and oversedation are rare but potentially devastating adverse events in hospitalised patients. We investigated which features predict an individual patient's risk of OIRD or oversedation; and developed a risk stratification tool that can be used to aid point-of-care clinical decision-making.

DESIGN

Retrospective observational study.

SETTING

Twelve acute care hospitals in a large not-for-profit integrated delivery system.

PARTICIPANTS

All inpatients ≥18 years admitted between 1 July 2016 and 30 June 2018 who received an opioid during their stay (163 190 unique hospitalisations).

MAIN OUTCOME MEASURES

The primary outcome was occurrence of sedation or respiratory depression severe enough that emergent reversal with naloxone was required, as determined from medical record review; if naloxone reversal was unsuccessful or if there was no evidence of hypoxic encephalopathy or death due to oversedation, it was not considered an oversedation event.

RESULTS

Age, sex, body mass index, chronic obstructive pulmonary disease, concurrent sedating medication, renal insufficiency, liver insufficiency, opioid naïvety, sleep apnoea and surgery were significantly associated with risk of oversedation. The strongest predictor was concurrent administration of another sedating medication (adjusted HR, 95% CI=3.88, 2.48 to 6.06); the most common such medications were benzodiazepines (29%), antidepressants (22%) and gamma-aminobutyric acid analogue (14.7%). The c-statistic for the final model was 0.755. The 24-point Oversedation Risk Criteria (ORC) score developed from the model stratifies patients as high (>20%, ≥21 points), moderate (11%-20%, 10-20 points) and low risk (≤10%, <10 points).

CONCLUSIONS

The ORC risk score identifies patients at high risk for OIRD or oversedation from routinely collected data, enabling targeted monitoring for early detection and intervention. It can also be applied to preventive strategies-for example, clinical decision support offered when concurrent prescriptions for opioids and other sedating medications are entered that shows how the chosen combination impacts the patient's risk.

Postpartum Respiratory Depression

Postpartum respiratory depression is a complex, multifactorial issue that encompasses a patient's baseline preexisting conditions, certain pregnancy-specific conditions or complications, as well as the iatrogenic element of various medications given in the peripartum period. In this review, we discuss many of these factors including obesity, sleep-disordered breathing, chronic lung disease, neuromuscular disorders, opioids, preeclampsia, peripartum cardiomyopathy, postpartum hemorrhage, amniotic fluid embolism, sepsis, acute respiratory distress syndrome (ARDS), and medications such as analgesics, sedatives, anesthetics, and magnesium. Current recommendations for screening, treatment, and prevention are also discussed.

Efficacy and safety of intrathecal morphine for analgesia after lower joint arthroplasty: a systematic review and meta-analysis with meta-regression and trial sequential analysis

Widespread adoption of intrathecal morphine into clinical practice is hampered by concerns about its potential side‐effects. We undertook a systematic review, meta‐analysis and trial sequential analysis with the primary objective of determining the efficacy and safety of intrathecal morphine. Our secondary objective was to determine the dose associated with greatest efficacy and safety. We also assessed the impact of intrathecal morphine on respiratory depression. We systematically searched the literature for trials comparing intrathecal morphine with a control group in patients undergoing hip or knee arthroplasty under spinal anaesthesia. Our primary efficacy outcome was rest pain score (0–10) at 8–12 hours; our primary safety outcome was the rate of postoperative nausea and vomiting within 24 hours. Twenty‐nine trials including 1814 patients were identified. Rest pain score at 8–12 hours was significantly reduced in the intrathecal morphine group, with a mean difference (95%CI) of −1.7 (−2.0 to −1.3), p < 0.0001 (19 trials; 1420 patients; high‐quality evidence), without sub‐group differences between doses (p = 0.35). Intrathecal morphine increased postoperative nausea and vomiting, with a risk ratio (95%CI) of 1.4 (1.3–1.6), p < 0.0001 (24 trials; 1603 patients; high‐quality evidence). However, a sub‐group analysis by dose revealed that rates of postoperative nausea and vomiting within 24 hours were similar between groups at a dose of 100 µg, while the risk significantly increased with larger doses (p value for sub‐group difference = 0.02). Patients receiving intrathecal morphine were no more likely to have respiratory depression, the risk ratio (95%CI) being 0.9 (0.5–1.7), p = 0.78 (16 trials; 1173 patients; high‐quality evidence). In conclusion, there is good evidence that intrathecal morphine provides effective analgesia after lower limb arthroplasty, without an increased risk of respiratory depression, but at the expense of an increased rate of postoperative nausea and vomiting. A dose of 100 µg is a ‘ceiling’ dose for analgesia and a threshold dose for increased rate of postoperative nausea and vomiting.

[Neuraxial Morphine for Postoperative Analgesia after Caesarean Deliveries]

The use of neuraxial morphine, in combination with nonopioid analgesic regimens for postoperative analgesia after Caesarean deliveries is common practice, especially in the Anglo-American world. Neuraxial morphine offers a longer-lasting superior analgesia than intravenous opioids or patient-controlled analgesia. If neuraxial anaesthesia is being used for a caesarean delivery, it may be recommended to concomitantly administer neuraxial morphine for the postoperative analgesia.A low dose of neuraxial morphine in a healthy parturient bears a low morbidity and mortality risk. The optimal frequency, duration and modality of respiratory monitoring for patients at low risk for respiratory depression is dependent on the dose of morphine administered and the patient-specific and obstetric risk profile.

Quantifying the incidence of clinically significant respiratory depression in women with and without obesity class III receiving neuraxial morphine for post-cesarean analgesia: a retrospective cohort study

BACKGROUND

Obesity is a suspected risk factor for respiratory depression following neuraxial morphine for post-cesarean analgesia, however monitoring guidelines for obese obstetric patients are based on small, limited studies. We tested the hypothesis that clinically significant respiratory depression following neuraxial morphine occurs more commonly in women with body mass index (BMI) ≥40 kg/m² compared with BMI <40 kg/m².

METHODS

We conducted a single-center, retrospective chart review (2006-2017) of obstetric patients with clinically significant respiratory depression following neuraxial morphine, defined as: (1) opioid antagonist administration; (2) rapid response team activation (initiated in April 2010); or (3) tracheal intubation due to a respiratory event. The incidence of respiratory depression was compared between women with BMI ≥40 kg/m² and BMI <40 kg/m².

RESULTS

In total, 11 327 women received neuraxial morphine (n=1945 BMI ≥40 kg/m²; n=9382 BMI <40 kg/m²). Women with BMI ≥40 kg/m² had higher rates of sleep apnea, hypertensive disorders, and magnesium administration. Sixteen cases of clinically significant respiratory depression occurred within seven days postpartum. The incidence did not significantly differ between groups (odds ratio 2.2, 95% CI 0.6 to 6.9, P=0.174). Neuraxial morphine was not deemed causative in any case, however women with BMI ≥40 kg/m² had higher rates of tracheal intubation unrelated to neuraxial morphine (2/1945 vs. 0/9382, P=0.029).

CONCLUSIONS

Respiratory depression in this population is rare. A larger sample (∼75 000) is required to determine whether the incidence is higher with BMI ≥40 kg/m². Tracheal intubation was higher among the BMI ≥40 kg/m² cohort, likely due to more comorbidities.

Strategies of analgesic treatment after cesarean delivery. Current state and new alternatives

The number of caesarean sections performed worldwide is increasing, and with it, the need for the optimal analgesia strategies. Deficient postoperative analgesia increases the need for opioids, delays recovery, and is associated with chronic pain and postpartum depression. It is essential to find good postoperative pain control strategies that facilitate early mobility, early recovery, and early hospital discharge with minimal side effects on the mother and infant. Multimodal analgesia based on neuroaxial anaesthesia with morphine in combination with non-opioids such as non-steroidal anti-inflammatory drugs and paracetamol, gives the best post-caesarean analgesia outcome, and allows anaesthesiologists to reserve opioids, corticoids, gabapentin, magnesium or ketamine for situations where neuroaxial anaesthesia cannot be performed, for high-risk patients, or when pain is difficult to control. Peripheral nerve block techniques can also be added, such as transverse abdominis plane block, erector spinae block, or continuous wound infiltration.

Prospective Observational Investigation of Capnography and Pulse Oximetry Monitoring After Cesarean Delivery With Intrathecal Morphine

BACKGROUND

Intrathecal morphine provides excellent analgesia after cesarean delivery; however, respiratory events such as apnea, bradypnea, and hypoxemia have been reported. The primary study aim was to estimate the number of apneas per subject, termed "apnea alert events" (AAEs) defined by no breath for 30-120 seconds, using continuous capnography in women who underwent cesarean delivery.

METHODS

We performed a prospective, observational study with institutional review board approval of women who underwent cesarean delivery with spinal anesthesia containing 150-µg intrathecal morphine. A STOP-Bang obstructive sleep apnea assessment was administered to all women. Women were requested to use continuous capnography and pulse oximetry for 24 hours after cesarean delivery. Nasal sampling cannula measured end-tidal carbon dioxide (EtCO2) and respiratory rate (RR), and oxygen saturation (SpO2) as measured by pulse oximetry. Capnography data were defined as "valid" when EtCO2 >10 mm Hg, RR >5 breaths per minute (bpm), SpO2 >70%, or during apnea (AAE) defined as "no breath" (EtCO2, <5 mm Hg) for 30-120 seconds. Individual respiratory variable alerts were 10-second means of EtCO2 <10 mm Hg, RR <8 bpm, and SpO2 <94%. Nurse observations of RR (hourly and blinded to capnography) are reported.

RESULTS

We recruited 80 women, mean (standard deviation [SD]) 35 (5) years, 47% body mass index >30 kg/m2/weight >90 kg, and 11% with suspected obstructive sleep apnea (known or STOP-Bang score >3). The duration of normal capnography and pulse oximetry data was mean (SD) (range) 8:28 (7:51) (0:00-22:32) and 15:08 (6:42) (1:31-23:07) hours:minutes, respectively; 6 women did not use the capnography. There were 198 AAEs, mean (SD) duration 57 (27) seconds experienced by 39/74 (53%) women, median (95% confidence interval for median) (range) 1 (0-1) (0-29) per subject. Observation of RR by nurses was ≥14 bpm at all time-points for all women, r = 0.05 between capnography and nurse RR (95% confidence interval, -0.04 to 0.14). There were no clinically relevant adverse events for any woman. Sixty-five women (82%) had complaints with the capnography device, including itchy nose, nausea, interference with nursing baby, and overall inconvenience.

CONCLUSIONS

We report 198 AAEs detected by capnography among women who underwent cesarean delivery after receiving intrathecal morphine. These apneas were not confirmed by the intermittent hourly nursing observations. Absence of observer verification precludes distinction between real, albeit nonclinically significant alerts with capnography versus false apneas. Discomfort with the nasal sampling cannula and frequent alerts may impact capnography application after cesarean delivery. No clinically relevant adverse events occurred.

Obesity And Obstetric Anesthesia: Current Insights

Obesity is a significant global health problem. It results in a higher incidence of complications for pregnant women and their neonates. Cesarean deliveries are more common in obese parturients as well. The increased burden of comorbidities seen in this population, such as obstructive sleep apnea, necessitates antepartum anesthetic consultation. These patients pose unique challenges for the practicing anesthesiologist and may benefit from optimization prior to delivery. Complications from anesthesia and overall morbidity and mortality are higher in this population. Neuraxial anesthesia can be challenging to place in the obese parturient, but is the preferred anesthetic for cesarean delivery to avoid airway manipulation, minimize aspiration risk, prevent fetal exposure to volatile anesthetic, and decrease risk of post-partum hemorrhage from volatile anesthetic exposure. Monitoring and positioning of these patients for surgery may pose specific challenges. Functional labor epidural catheters can be topped up to provide conditions suitable for surgery. In the absence of a working epidural catheter, a combined spinal epidural anesthetic is often the technique of choice due to relative ease of placement versus a single shot spinal technique as well as the ability to extend the anesthetic through the epidural portion. For cesarean delivery with a vertical supraumbilical skin incision, a two-catheter technique may be beneficial. Concern for thromboembolism necessitates early mobilization and a multimodal analgesic regimen can help accomplish this. In addition, thromboprophylaxis is recommended in this population after delivery—especially cesarean delivery. These patients also need close monitoring in the post-partum period when they are at increased risk for several complications.

Obstructive Sleep Apnea in Pregnant Women: A Review of Pregnancy Outcomes and an Approach to Management

Among obese pregnant women, 15%-20% have obstructive sleep apnea (OSA) and this prevalence increases along with body mass index and in the presence of other comorbidities. Prepregnancy obesity and pregnancy-related weight gain are certainly risk factors for sleep-disordered breathing in pregnancy, but certain physiologic changes of pregnancy may also increase a woman's risk of developing or worsening OSA. While it has been shown that untreated OSA in postmenopausal women is associated with a range of cardiovascular, pulmonary, and metabolic comorbidities, a body of literature is emerging that suggests OSA may also have serious implications for the health of mothers and fetuses during and after pregnancy. In this review, we discuss the following: pregnancy as a vulnerable period for the development or worsening of OSA; the associations between OSA and maternal and fetal outcomes; the current screening modalities for OSA in pregnancy; and current recommendations regarding peripartum management of OSA.

Incidence of respiratory depression after epidural administration of morphine for cesarean delivery: findings using a continuous respiratory rate monitoring system

BACKGROUND

Epidural morphine is widely used for postoperative analgesia after cesarean delivery. However, respiratory depression can occur after neuraxial administration of morphine. Previous reports describing respiratory depression in obstetric patients have relied on intermittent visual counting of the respiratory rate. In this study, we estimated the incidence of respiratory depression in patients who had received epidural morphine after cesarean delivery, using a continuous respiratory rate monitoring system with a finger sensor.

METHODS

One hundred patients scheduled to undergo elective cesarean delivery and receive intraoperative neuraxial morphine between April and December 2016 were recruited for this single-center, prospective observational study. Postoperatively, all patients received epidural morphine 3 mg and were equipped with the Nellcor respiratory rate monitoring system. Respiratory depression was defined as both bradypnea (respiratory rate ≤10 breaths/min) and oxygen desaturation (mild ≤95%; moderate ≤90%; severe ≤85%) for longer than one minute. The number of patients with respiratory depression between administration of morphine and first ambulation was recorded hourly.

RESULTS

Complete monitoring was obtained for 89 of 100 women. The median duration of monitoring was 19.0 hours. Forty-six patients (52%) developed mild respiratory depression at least once before ambulation, but only one (1%) developed moderate respiratory depression. None required supplemental oxygen or naloxone.

CONCLUSIONS

Approximately half the women experienced mild respiratory depression, but only one developed moderate respiratory depression. Continuous respiratory rate monitoring until ambulation may assist in early identification of respiratory depression after neuraxial administration of morphine.

Neuraxial morphine after unintentional dural puncture is not associated with reduced postdural puncture headache in obstetric patients

STUDY OBJECTIVE

To examine the relationship between neuraxial morphine exposure after unintentional dural puncture and the risk for postdural puncture headache in obstetric patients.

DESIGN

Retrospective cohort study.

SETTING

Obstetrical unit at a tertiary care referral center.

PATIENTS

Parturients receiving labor epidural analgesia with recognized unintentional dural puncture.

INTERVENTIONS

Cases in which neuraxial morphine was given for any reason were compared to cases in which it was not for the outcome of postdural puncture headache.

MEASUREMENTS

Development of postdural puncture headache, headache severity, number of epidural blood patches, hospital length of stay.

MAIN RESULTS

Of the 80 cases that were included, 38 women received neuraxial morphine and 42 did not. There was no significant difference in the incidence of headache between the two morphine groups (Headache present: Morphine: 27/56 [48.2%], No morphine: 29/56 [51.8%]; Headache free: Morphine: 11/24 [45.8%], No morphine: 13/24 [54.2%], P = 0.84). There was no difference in the need for epidural blood patch (Morphine: 24/42 [57.1%], No morphine: 18/38 [47.4%], P = 0.50) and headache severity (mean headache pain score: Morphine: 7.9 ± 1.8 vs. No morphine: 7.3 ± 2.4, P = 0.58). Hospital length of stay was higher in the morphine group (4.4 ± 2.9 days vs. 3.0 ± 1.5 days respectively, P = 0.008). Using logistic regression, morphine did not affect headache risk after controlling for covariates (morphine vs. no morphine: adjusted OR 1.24 [0.75]; P = 0.72; pre-eclampsia vs. no pre-eclampsia: adjusted OR 0.56 [0.41], P = 0.42; cesarean vs. normal spontaneous vaginal delivery: adjusted OR 0.97 [0.67]; P = 0.96).

CONCLUSION

In cases of unintentional dural puncture, exposure to neuraxial morphine for any reason may not be protective against the risk of postdural puncture headache. Although an overall protective effect of neuraxial morphine was not observed in this study, its role in specific subsets of patients remains to be investigated.

Management of Obstructive Sleep Apnea in Pregnancy

The spectrum of sleep-disordered breathing (SDB) ranges from mild snoring to obstructive sleep apnea, the most severe form of SDB. Current recommendations are to treat these women with continuous positive airway pressure despite limited data. SDB in early and mid-pregnancy is associated with preeclampsia and gestational diabetes. Pregnant women with a diagnosis of obstructive sleep apnea at delivery were at significantly increased risk of having cardiomyopathy, congestive heart failure, pulmonary embolism, and in-hospital death. These effects were exacerbated in the presence of obesity. Postpartum, these women are at risk for respiratory suppression and should be monitored.

The impact of neuraxial clonidine on postoperative analgesia and perioperative adverse effects in women having elective Caesarean section-a systematic review and meta-analysis

Neuraxial clonidine improves postoperative analgesia in the general surgical population. The efficacy and safety of neuraxial clonidine as a postoperative analgesic adjunct in the Caesarean section population still remains unclear. This systematic review and meta-analysis aims to evaluate the effect of perioperative neuraxial clonidine on postoperative analgesia in women having Caesarean section under neuraxial anaesthesia. We included randomized controlled trials comparing the analgesic efficacy of the perioperative administration of neuraxial clonidine alone or in combination with a local anaesthetic and/or opioids in women having elective Caesarean section under neuraxial anaesthesia when compared with placebo. PubMed, the Cochrane Central Register of Controlled Trials, and EMBASE were searched until February 2017. Eighteen studies were included in the meta-analysis. Neuraxial clonidine reduced 24 h morphine consumption [mean difference (MD): -7.2 mg; 95% confidence interval (CI): -11.4, -3.0 mg; seven studies] and prolonged time to first analgesic request (MD: 135 min; 95% CI: 102, 168 min; 16 studies) when compared with the control group. Neuraxial clonidine increased intraoperative hypotension [odds ratio (OR): 2.849; 95% CI: 1.363, 5.957], intraoperative sedation (OR: 2.355; 95% CI: 1.016, 5.459), but reduced the need for intraoperative analgesic supplementation (OR: 0.224; 95% CI: 0.076, 0.663). The effect of clonidine on intraoperative bradycardia, intraoperative and postoperative nausea and vomiting, postoperative sedation, and pruritus were inconclusive. Neuraxial clonidine did not negatively impact neonatal umbilical artery pH or Apgar scores. This review demonstrates that neuraxial clonidine enhances postoperative analgesia in women having Caesarean section with neuraxial anaesthesia, but this has to be balanced against increased maternal adverse effects.

Portable respiratory polygraphy monitoring of obese mothers the first night after caesarean section with bupivacaine/morphine/fentanyl spinal anaesthesia

Background: Obesity, abdominal surgery, and intrathecal opioids are all factors associated with a risk for respiratory compromise. The aim of this explorative trial was to study the apnoea/hypopnea index 1st postoperative night in obese mothers having had caesarean section (CS) in spinal anaesthesia with a combination of bupivacaine/morphine and fentanyl. Methods: Consecutive obese (BMI >30 kg/m 2) mothers, ≥18 years, scheduled for CS with bupivacaine/morphine/fentanyl spinal anaesthesia were monitored with a portable polygraphy device Embletta /NOX on 1 st postoperative night. The apnoea/hypopnea index (AHI) was identified by clinical algorithm and assessed in accordance to general guidelines; number of apnoea/hypopnea episodes per hour: <5 "normal", ≥5 and <15 mild sleep apnoea, ≥15 and <30 moderate sleep apnoea, ≥ 30 severe sleep apnoea. Oxygen desaturation events were in similar manner calculated per hour as oxygen desaturation index (ODI). Results: Forty mothers were invited to participate: 27 consented, 23 were included, but polysomnography registration failed in 3. Among the 20 mothers studied: 11 had an AHI <5 ( normal), 7 mothers had AHI ≥5 but <15 ( mild OSAS) and 2 mothers had AHI ≥15 ( moderate OSA), none had an AHI ≥ 30. The ODI was on average 4.4, and eight patients had an ODI >5. Mothers with a high AHI (15.3 and 18.2) did not show high ODI. Mean saturation was 94% (91-96%), and four mothers had mean SpO 2 90-94%, none had a mean SpO2 <90%. Conclusion: Respiratory polygraphy 1 st night after caesarean section in spinal anaesthesia with morphine in moderately obese mothers showed AHIs that in sleep medicine terms are considered normal, mild and moderate. Obstructive events and episodes of desaturation were commonly not synchronised. Further studies looking at preoperative screening for sleep apnoea in obese mothers are warranted but early postop respiratory polygraphy recording is cumbersome and provided sparse important information.

Portable respiratory polygraphy monitoring of obese mothers the first night after caesarean section with bupivacaine/morphine/fentanyl spinal anaesthesia

Background: Obesity, abdominal surgery, and intrathecal opioids are all factors associated with a risk for respiratory compromise. The aim of this observational study was to explore the use of portable respiratory polygraphy for monitoring of obese mothers for respiratory depression the first night after caesarean section (CS) with bupivacaine/morphine/fentanyl spinal anaesthesia. Methods: Consecutive obese (BMI >30 kg/m 2) mothers, ≥18 years, scheduled for CS with bupivacaine/morphine/fentanyl spinal anaesthesia were monitored with a portable polygraphy device Embletta /NOX on the first postoperative night. The apnoea-hypopnea index (AHI) was identified by clinical algorithm and assessed in accordance to general guidelines. Results: Forty mothers were invited to participate: 27 consented, 23 were included, but polysomnography registration failed in 3. Among the 20 mothers: 11 had an AHI <5; 7, AHI 5-15; and 2, AHI >15. The oxygen desaturation index (ODI) was on average 4.4, and eight patients had an ODI >5. Those mothers with a high AHI (15.3 and 18.2) did not show high ODI or signs of hypercapnia on transcutaneous CO 2 registration. Mean saturation was 94% (91-96), and four mothers had mean saturation between 90-94%, but none had a mean SpO 2 <90%. Mean nadir saturation was 71% (range, 49-81%).  None of the mothers showed clinical signs or symptoms of severe respiratory depression, shown by routine clinical monitoring. Conclusion: We found portable polygraphy registration during early post-CS in moderately obese mothers having had intrathecal morphine/fentanyl cumbersome and although episodes of oxygen saturation decrease were noticed, obstructive events and episodes of desaturation were commonly not synchronised. Upper airway obstructions seem not be of major importance in this clinical setting. Monitoring of respiratory rate, SpO 2 and possibly transcutaneous CO 2 in mothers at high risk of respiratory distress warrants further studies. Preoperative screening in obese patients, at risk for sleep breathing disorder, is of course of value.

Effect of oxycodone patient-controlled intravenous analgesia after cesarean section: a randomized controlled study

Background

Oxycodone is a semisynthetic μ-opioid receptor agonist with a potentially good analgesic efficacy in visceral pain. This study aims to compare the efficacy of oxycodone with sufentanil patient-controlled intravenous analgesia (PCIA).

Methods

One hundred and twenty primiparas undergoing elective cesarean section were randomized into four groups by different drugs of PCIA: group S (sufentanil 100 μg), group OS1 (sufentanil 70 μg, oxycodone 30 mg), group OS2 (sufentanil 50 μg, oxycodone 50 mg), and group O (oxycodone 100 mg). Ramosetron 0.3 mg was added to each group. In all groups, drugs were diluted to 100 mL and managed with a continuous infusion of 1 mL·h⁻¹, a bolus dose of 2 mL, and a lockout interval of 15 min. The maximum dose of PCIA per hour was 10 mL. After surgery, pain scores, PCIA doses, and side effects were compared among groups.

Results

At all time points (6, 12, and 24 h after surgery), Numerical Rating Scale (NRS) of uterine cramping pain (NRS-U) scores in group O were lower than those in groups OS1 and S (P<0.008) and NRS-U scores in groups OS2 and OS1 were lower than that in group S (P<0.008). NRS of moving into the sitting position (NRS-S) scores in group O were lower than those in the other groups (P<0.008). NRS-S scores in group OS2 were lower than those in groups OS1 and S (P<0.008). At 12 and 24 h after surgery, NRS of incision pain at rest (NRS-R) scores in group O were lower than those in the other groups (P<0.008). At all time points, NRS-R scores in group OS2 were lower than those in groups OS1 and S (P<0.008). The number of PCIA boluses and amount of opioid consumption in group O were lower than those in groups OS1 and S at all time points (P<0.008).

Conclusion

Oxycodone PCIA may be more effective than sufentanil PCIA for pain relief after cesarean section but the incidence of side effects needs further investigation.

Intra-incisional liposomal bupivacaine and its impact on postcesarean analgesia: a retrospective study

PURPOSE

The efficacy of long-acting intraincisional bupivacaine in reducing postoperative opioid use among women who have undergone a cesarean is currently unknown.

MATERIALS AND METHODS

This was a retrospective case-control study with a 1:1 allocation. We identified 40 patients in each group, for a total of 80. The treatment group was administered 266 mg of liposomal bupivacaine after completion of the cesarean and was compared to historical controls. Data regarding anesthesia administered, opioid consumption, nonsteroidal anti-inflammatory use, acetaminophen use, type of cesarean, reason for cesarean, and length of postoperative stay were recorded.

RESULTS

The treatment group used 41.51 mg of morphine equivalents, while the control group consumed 69.90 mg (p < .001); multivariate analysis demonstrated a mean difference of 26.52 mg (95%CI 12.76-40.28). Univariate analysis demonstrated mean difference in intravenous (IV) ketorolac (40.77 mg, p < .001) and IV acetaminophen (1333.33 mg, p < .001) was different and greater in the treatment group; this was controlled for in the multivariate model. There was no difference in oral and IV ibuprofen or oral acetaminophen use between groups. There were no differences between the type of anesthesia, length of stay, reason for cesarean, and classical sections between groups.

CONCLUSIONS

Incisional administration of liposomal bupivacaine may be an effective adjunct in reducing opioid use postoperatively and may be a useful adjunct within an enhanced recovery program.

Transcutaneous Carbon Dioxide Measurements in Women Receiving Intrathecal Morphine for Cesarean Delivery: A Prospective Observational Study

BACKGROUND

Neuraxial morphine is the most commonly used analgesic technique after cesarean delivery. The incidence of respiratory depression is reported to be very low (0%-1.2%) in this patient population as measured by pulse oximetry and respiratory rates. However, hypercapnia may be a more sensitive measure of respiratory depression. In the current study, the incidence of hypercapnia events (transcutaneous CO2 [TcCO2] >50 mm Hg) for ≥2-minute duration was evaluated using the Topological Oscillation Search with Kinematical Analysis monitor in women who received intrathecal morphine for postcesarean delivery analgesia.

METHODS

Healthy women (>37 weeks of gestation) scheduled for a cesarean delivery with spinal anesthesia with intrathecal morphine were recruited. Baseline STOP-BANG sleep apnea questionnaire and TcCO2 readings were obtained. Spinal anesthesia was initiated with 12 mg hyperbaric bupivacaine, 15 µg fentanyl, and 150 µg morphine. The Topological Oscillation Search with Kinematical Analysis monitor was reapplied in the postanesthesia care unit and TcCO2 measurements obtained for up to 24 hours. Supplemental opioid administration and adverse respiratory events were recorded. The primary outcome was the incidence of hypercapnia events, defined as a TcCO2 reading >50 mm Hg for ≥2 minutes in the first 24 hours after delivery.

RESULTS

Of the 120 women who were recruited, 108 completed the study. Thirty-five women (32%; 99.15% confidence interval, 21%-45%) reached the primary outcome of a sustained hypercapnia event. The median time (interquartile range [IQR]) from intrathecal morphine administration to the hypercapnia event was 300 (124-691) minutes. The median (IQR) number of events was 3 (1-6) and longest duration of an event was 25.6 (8.4-98.7) minutes. Baseline median (IQR) TcCO2 measurements were 35 (30-0) mm Hg and postoperatively, median (IQR) TcCO2 measurements were 40 (36-43) mm Hg, a difference of 5 mm Hg (99.15% confidence interval of the difference 2-8 mm Hg, P < .001). The incidence of hypercapnia events was 5.4% in women with a baseline TcCO2 value ≤31 mm Hg, 22.5% with a baseline TcCO2 between 32 and 38 mm Hg, and 77.4% with a baseline TcCO2 >38 mm Hg (P < .001).

CONCLUSIONS

Hypercapnia events (>50 mm Hg for ≥2-minute duration) occurred frequently in women receiving 150 μg intrathecal morphine for postcesarean analgesia. Higher baseline TcCO2 readings were observed in women who had hypercapnia events.

A prospective study of post-cesarean delivery hypoxia after spinal anesthesia with intrathecal morphine 150μg

INTRODUCTION

Delayed respiratory depression is a feared complication of intrathecal morphine in patients undergoing cesarean delivery. The incidence, timing and risk factors for hypoxia in this population are not known.

METHODS

Patients undergoing cesarean delivery under spinal anesthesia at a tertiary care center from October 2012 to March 2016 were included in the study. The Berlin sleep apnea Questionnaire was completed before surgery. Oxygen saturation was recorded every second for 24hours after the initiation of spinal anesthesia. Desaturation events were defined as a median saturation of <90% (mild) or <85% (severe) across a 30-s period. Multivariable logistic regression was used to determine predictors of a desaturation event.

RESULTS

A total of 721 patients were included in the analysis. Within this cohort, 169 women (23%) experienced at least one mild desaturation event, 91 (13%) experienced two or more mild desaturations, and 26 (4%) suffered a severe desaturation event. After the administration of intrathecal morphine, the median times to first mild or first severe desaturation were 7.4 (IQR 4.1-13.5)h and 12.0 (IQR 5.4-19.6)h, respectively. Patients who screened positive for sleep apnea had increased odds of having a mild desaturation event (OR 2.31, 95% CI 1.40 to 3.79, P=0.001), as did patients who were obese (OR 1.80, 95% CI 1.05 to 3.09, P=0.033).

CONCLUSIONS

Mild hypoxemia occurred frequently in women receiving intrathecal morphine 150μg for post-cesarean analgesia. Desaturations were observed most frequently 4-8hours after administration of intrathecal morphine. Obesity and a positive Berlin Questionnaire were risk factors for hypoxemic events.

Anesthetic Considerations in the Obese Parturient

The provision of anesthesia to the morbidly obese parturient is technically challenging. The anesthesia provider anticipates difficulty with intravenous access, positioning, monitoring, and placement of neuraxial anesthesia. There is a higher incidence of hypotension in obese parturients during neuraxial anesthesia most likely due to concealed aortocaval compression as positioning these patients is difficult. Most providers will provide either epidural or combined spinal/epidural anesthesia for cesarean delivery due to the variable duration of the surgical procedure. Among obese gravidas, there is a lower risk of the development of a headache from an accidental dural puncture, due not to the body habitus, but rather to the group's higher cesarean delivery rate. It is the process of bearing down during delivery that increases the chance of the development of a headache following dural puncture.

Managing anesthesia for cesarean section in obese patients: current perspectives

Obesity is a worldwide epidemic. It is associated with increased comorbidities and increased maternal, fetal, and neonatal complications. The risk of cesarean delivery is also increased in obese parturients. Anesthetic management of the obese parturient is challenging and requires adequate planning. Therefore, those patients should be referred to antenatal anesthetic consultation. Anesthesia-related complications and maternal mortality are increased in this patient population. The risk of difficult intubation is increased in obese patients. Neuraxial techniques are the preferred anesthetic techniques for cesarean delivery in obese parturients but can be technically challenging. An existing labor epidural catheter can be topped up for cesarean delivery. In patients who do not have a well-functioning labor epidural, a combined spinal epidural technique might be preferred over a single-shot spinal technique since it is technically easier in obese parturients and allows for extending the duration of the block as required. A continuous spinal technique can also be considered. Studies suggest that there is no need to reduce the dose of spinal bupivacaine in the obese parturient, but there is little data about spinal dosing in super obese parturients. Intraoperatively, patients should be placed in a ramped position, with close monitoring of ventilation and hemodynamic status. Adequate postoperative analgesia is crucial to allow for early mobilization. This can be achieved using a multimodal regimen incorporating neuraxial morphine (with appropriate observations) with scheduled nonsteroidal anti-inflammatory drugs and acetaminophen. Thromboprophylaxis is also important in this patient population due to the increased risk of thromboembolic complications. These patients should be monitored carefully in the postoperative period, since there is increased risk of postoperative complications in the morbidly obese parturients.

Ultrasound-guided transversus abdominis plane block for post-operative analgesia in patients undergoing caesarean section

BACKGROUND AND AIMS

Transversus abdominis plane (TAP) block is a fascial plane block providing post-operative analgesia in patients undergoing surgery with infra-umbilical incisions. We evaluated analgesic efficacy of TAP block with ropivacaine for 24 h after caesarean section through a Pfannenstiel incision.

METHODS

Sixty patients undergoing caesarean section under spinal anaesthesia were randomised to undergo TAP block with ropivacaine (n = 30) versus control group (n = 30) with normal saline, in addition to standard analgesia with intravenous paracetamol and tramadol. At the end of the surgery, ultrasound-guided TAP plane block was given bilaterally using ropivacaine or normal saline (15 ml on either side). Each patient was assessed post-operatively by a blinded investigator at regular intervals up to 24 h for visual analogue score (VAS) and requirement of analgesia. SPSS version 18.0 software was used. Demographic data were analysed using Student's t-test and the other parameters using paired t-test.

RESULTS

TAP block with ropivacaine compared with normal saline reduced post-operative VAS at 24 h (P = 0.004918). Time for rescue analgesia in the study group was prolonged from 4.1 to 9.53 h (P = 0.01631). Mean requirement of tramadol in the first 24 h was reduced in the study group.

CONCLUSION

US guided TAP block after caesarean section reduces the analgesic requirement in the first 24 h.

Anesthetic management of super-morbidly obese parturients for cesarean delivery with a double neuraxial catheter technique: a case series

Parturients with super-morbid obesity, defined as body mass index greater than 50kg/m(2), represent a growing segment of patients who require anesthetic care for labor and delivery. Severe obesity and its comorbid conditions place the parturient and fetus at greater risk for pregnancy complications and cesarean delivery, as well as surgical and anesthetic complications. The surgical approach for cesarean delivery in these patients may require a supra-umbilical vertical midline incision due to a large pannus. The dense T4-level of spinal anesthesia can cause difficulties with ventilation for the obese patient during the procedure, which can be prolonged. Patients also may have respiratory complications in the postoperative period due to pain from the incision. We describe the anesthetic management of three parturients with body mass index ranging from 73 to 95kg/m(2) who had a cesarean delivery via a supra-umbilical vertical midline incision. Continuous lumbar spinal and low thoracic epidural catheters were placed in each patient for intraoperative anesthesia and postoperative analgesia, respectively. Continuous spinal catheters were dosed with incremental bupivacaine boluses to achieve surgical anesthesia. In one case, the patient required respiratory support with non-invasive positive pressure ventilation. Two cases were complicated by intraoperative hemorrhage. All patients had satisfactory postoperative analgesia with a thoracic epidural infusion. None suffered postoperative respiratory complications or postdural puncture headache. The use of a continuous lumbar spinal catheter and a low thoracic epidural provides several advantages in the anesthetic management of super-morbidly obese parturients for cesarean delivery.

Endogenous opiates and behavior: 2013

This paper is the thirty-sixth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2013 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia; stress and social status; tolerance and dependence; learning and memory; eating and drinking; alcohol and drugs of abuse; sexual activity and hormones, pregnancy, development and endocrinology; mental illness and mood; seizures and neurologic disorders; electrical-related activity and neurophysiology; general activity and locomotion; gastrointestinal, renal and hepatic functions; cardiovascular responses; respiration and thermoregulation; and immunological responses.

Investigation and analysis of oncologists' knowledge of morphine usage in cancer pain treatment

Purpose

To examine oncologists’ knowledge of cancer pain and morphine’s clinical application in the People’s Republic of China. In addition, this study analyzes and discusses the negative factors that currently affect the clinical application of morphine.

Patients and methods

A questionnaire survey was given to a random sample of 150 oncologists from Tianjin Medical University Cancer Institute and Hospital. The statistical results were analyzed and processed using SPSS version 21.0 and Matlab version 2012a statistical software. Single-factor analysis of variance, Kruskal–Wallis nonparametric test, and independent samples t-test were adopted to analyze the difference in knowledge scores of morphine usage. The study also identified major impediment factors on clinical use of morphine.

Results

Among the 127 respondents, morphine controlled-release tablets were the most popular drug chosen to treat severe cancer pain (76 respondents, 35.8%). Participants who reported having received training in cancer pain management and drug use demonstrated a significantly higher mean score of basic knowledge compared with their untrained peers (11.51±2.60 versus 9.28±3.68, t=2.48, P=0.022). The top four barriers to widespread clinical use of morphine for cancer pain were 1) insufficient analgesia administration training for medical personnel, 2) poor patient compliance, 3) drug side effects, and 4) concerns surrounding drug addiction.

Conclusion

The oncologists in the People’s Republic of China simultaneously lack comprehensive knowledge and harbor misconceptions with regard to cancer pain treatment and morphine’s clinical application. Creating professional training initiatives for oncologists is necessary to enhance their awareness and expertise in morphine use for cancer pain treatment.