Retrospective Review of Intrathecal Hydromorphone Dose Range and Complications

BACKGROUND

Optimal intrathecal dosing regimens for hydromorphone are not well established for analgesia after abdominal surgery.

OBJECTIVES

We reviewed intrathecal hydromorphone doses and complications because dosing variability has been observed among anesthesiologists. We hypothesized that increasing doses of intrathecal hydromorphone would be associated with improved postoperative analgesia, but with increased rates of opioid-related adverse events.

STUDY DESIGN

Retrospective analysis.

SETTING

A high-volume academic referral center in the United States.

METHODS

A retrospective study was conducted of adults undergoing abdominal surgery under general anesthesia supplemented preoperatively with intrathecal hydromorphone for postoperative analgesia from May 5, 2018, through May 31, 2021. Patients were categorized into 3 hydromorphone dosing groups: low-dose (50-100 µg), middle-dose (101-199 µg), and high-dose (200-300 µg). Multivariable logistic regression models were used to assess rates of severe postoperative pain, severe opioid-related adverse events, oversedation, and pruritus in the postanesthesia care unit (PACU) and within 24 hours after PACU discharge.

RESULTS

Of 1,846 patients identified, 1,235 (66.9%) were in the low-dose group; 321 (17.3%), middle-dose group; and 290 (15.7%), high-dose group. Patients receiving the 2 higher doses had more extensive procedures. An unadjusted analysis showed differing rates of severe pain in the PACU by group: 306 (24.8%) in the low-dose, 73 (22.7%) middle-dose, and 45 (15.5%) in the high-dose group (P = 0.003); these differences, however, were no longer significant after an adjusted analysis (P = 0.34). Ten severe opioid-related events occurred; all were recognized in the PACU. Five events each occurred in the low-dose and high-dose groups versus none in the middle-dose group (P = 0.02). No other differences were identified with adjusted analyses.

LIMITATIONS

Limitations of our study include its retrospective design and its conduct at a single center, along with the apparent, but difficult to characterize, treatment biases in hydromorphone dosing.

CONCLUSIONS

No dose response was observed between intrathecal hydromorphone dose and postoperative analgesia, a finding that may reflect treatment bias. Higher rates of severe opioid-related events were detected for patients receiving high-dose hydromorphone in the PACU, but all other safety outcomes were similar between dosing regimens.

KEY WORDS

Drug-related side effects, opioid analgesics, outcome assessment, postoperative pain, spinal injections.

Effect of an oxytocin protocol on secondary uterotonic use in patients undergoing Cesarean delivery

PURPOSE

Protocol-driven oxytocin regimens can reduce oxytocin administration compared with a nonprotocol free-flow continuous infusion. Our aim was to compare secondary uterotonic use between a modified "rule of threes" oxytocin protocol and a free-flow continuous oxytocin infusion after Cesarean delivery.

METHODS

We conducted a retrospective before-and-after study to compare patients who underwent Cesarean delivery between 1 January 2010 and 31 December 2013 (preprotocol) with patients who underwent Cesarean delivery between 1 January 2015 and 31 August 2017 (postprotocol). The preprotocol group received free-flow oxytocin administration and the postprotocol group received oxytocin according to a modified rule of threes algorithm. The primary outcome was secondary uterotonic use and the secondary outcomes included blood transfusion, hemoglobin value < 8 g·dL-1, and estimated blood loss.

RESULTS

In total, 4,010 Cesarean deliveries were performed in 3,637 patients (2,262 preprotocol and 1,748 postprotocol). The odds of receiving secondary uterotonic drugs were increased in the postprotocol group (odds ratio [OR], 1.33; 95% confidence interval [CI], 1.04 to 1.70; P = 0.02). Patients in the postprotocol group were less likely to receive a blood transfusion. Nevertheless, the two groups were similar for the composite end point of transfusion or hemoglobin < 8 g·dL-1 (OR, 0.86; 95% CI, 0.66 to 1.11; P = 0.25). The odds of an estimated blood loss greater than 1,000 mL were reduced in the postprotocol group (OR, 0.64; 95% CI, 0.50 to 0.84; P = 0.001).

CONCLUSIONS

Patients in the modified rule of threes oxytocin protocol group were more likely to receive a secondary uterotonic than those in the preprotocol group. Estimated blood loss and transfusion outcomes were similar.

Simulation Training Effects on Resident-Perceived Readiness for Obstetric Anesthesia Rotation

Background

Beginning an unfamiliar rotation can be challenging as residents must expand their knowledge and skills to meet new clinical expectations, work with a new team of providers, and sometimes care for a new patient demographic. This may detract from learning, resident well-being, and patient care.

Methods

We implemented an obstetric anesthesia simulation session for anesthesiology residents prior to their first obstetric anesthesia rotation and measured the effect on residents' self-perceived preparedness.

Results

The simulation session increased residents' feelings of preparedness for the rotation and increased residents' confidence in specific obstetric anesthesia skills.

Conclusions

Importantly, this study shows the potential for the use of a prerotation, rotation-specific simulation session to better prepare learners for rotations.

Peripartum anesthetic management in patients with left ventricular noncompaction: a case series and review of the literature

BACKGROUND

This retrospective review focuses on peripartum anesthetic management and outcome of a series of five pregnant women with left ventricular noncompaction (LVNC).

METHODS

The Mayo Clinic Advanced Cohort Explorer medical database was utilized to identify women diagnosed with LVNC who had been admitted for delivery at the Mayo Clinic in Rochester, Minnesota between January 2001 and September 2021. Echocardiograms were independently reviewed by two board-certified echocardiographers, and those determined by both to meet the Jenni criteria and/or having compatible findings on magnetic resonance imaging (MRI) were included. Electronic medical records were reviewed for information pertaining to cardiac function, labor, delivery, and postpartum management.

RESULTS

We identified 44 patients whose medical record included the term "noncompaction" or "hypertrabeculation" and who had delivered at our institution during the study period. Upon detailed review of the medical records, 36 did not meet criteria for LVNC, and three additional patients did not receive the diagnosis until after delivery, leaving five patients with confirmed LVNC who had undergone six deliveries during the study interval. All five patients had a history of arrhythmias or had developed arrhythmias during pregnancy. One patient underwent emergency cesarean delivery due to sustained ventricular tachycardia requiring three intra-operative cardioversions.

CONCLUSIONS

This case series adds new evidence to that already available about pregnancies among women with LVNC. Favorable obstetrical outcomes were achievable when multidisciplinary teams were prepared to manage the maternal and fetal consequences of intrapartum cardiac arrhythmias and hemodynamic instability.

Obstetric Anesthetic Management for Parturients with Hereditary Angioedema: A Case Report and Suggested Protocol

Hereditary angioedema (HAE) is a disease manifested by repeated episodes of localized submucosal or subcutaneous edematous episodes, potentially triggered by emotional stress, mechanical trauma, or intake of estrogens. We present our experience managing two parturients with HAE. Multidisciplinary care is essential for planning and executing the specialized care of these patients, and management included extensive planning among obstetric, anesthesiology, and allergy and immunology teams. Pregnancy has been shown to have a variable effect on triggering HAE episodes. First-line treatment includes C1 esterase inhibitor concentrate, which can also be used for prophylaxis in high-risk patients. Neuraxial analgesia is recommended to avoid general anesthesia and was established early in both individuals. Vaginal delivery was well tolerated without need for emergent treatment for angioedema symptoms.

Effect of penicillin allergy on prophylactic antibiotic administration in the parturient undergoing cesarean delivery

BACKGROUND

Administering antibiotics is often difficult in patients with specific medication allergies. This investigation aimed to determine if a penicillin or cephalosporin allergy increased the risk for not receiving correct timing of prophylactic antibiotics at cesarean delivery. We hypothesized that patients with a penicillin or cephalosporin allergy would be less likely to receive antibiotics prior to incision for cesarean delivery.

METHODS

All women undergoing cesarean delivery at Mayo Clinic Hospital, from 1 March 2008, to 28 February 2018 were retrospectively identified by electronic medical record query. Patients were grouped based on allergy status to penicillin/cephalosporins. Data recorded included the type and time of antibiotic given in relation to surgical incision. The primary outcome of this study was administration of antibiotics within 60 minutes prior to surgical incision. Characteristics potentially associated with the primary outcome were assessed using logistic regression.

RESULTS

Of the 818 patients with a penicillin or cephalosporin allergy, 75 (9.2%) did not receive prophylactic antibiotic within 60 minutes prior to skin incision. Conversely, 326 (6.9%) of the 4744 patients without a penicillin or cephalosporin allergy did not receive their prophylactic antibiotic within 60 minutes prior to skin incision (P = .019). Patients undergoing an emergent cesarean delivery were also at an increased risk of not receiving their prophylactic antibiotic within 60 minutes prior to skin incision (P < .001).

CONCLUSION

Patients with a penicillin or cephalosporin allergy were less likely to receive prophylactic antibiotics within the recommended 60 minutes prior to surgical incision. Clear plans and communication are important for ensuring proper antibiotic administration at cesarean delivery to prevent surgical site infection.

Creating a model to predict time intervals from induction of labor to induction of anesthesia and delivery to coordinate workload

BACKGROUND

Induction of labor continues to become more common. We analyzed induction of labor and timing of obstetric and anesthesia work to create a model to predict the induction-anesthesia interval and the induction-delivery interval in order to co-ordinate workload to occur when staff are most available.

METHODS

Patients who underwent induction of labor at a single medical center were identified and multivariable linear regression was used to model anesthesia and delivery times. Data were collected on date of birth, race/ethnicity, body mass index, gestational age, gravidity, parity, indication for labor induction, number of prior deliveries, time of induction, induction agent, cervical dilation, effacement, and fetal station on admission, date and time of anesthesia administration, date and time of delivery, and delivery type.

RESULTS

A total of 1746 women met inclusion criteria. Associations which significantly influenced time from induction of labor to anesthesia and delivery included maternal age (anesthesia P <0.001, delivery P =0.002), body mass index (both P <0.001), prior vaginal delivery (both P <0.001), gestational age (anesthesia P <0.001, delivery P <0.018), simplified Bishop score (both P <0.001), and first induction agent (both P <0.001). Induction of labor of nulliparous women at 02:00 h and parous women at 04:00 or 05:00 h had the highest estimated probability of the mother having her first anesthesia encounter and delivering during optimally staffed hours when our institution's specialty personnel are most available.

CONCLUSIONS

Time to obstetric and anesthesia tasks can be estimated to optimize induction of labor start times, and shift anesthesia and delivery workload to hours when staff are most available.

Complication rate of ultrasound-guided paravertebral block for breast surgery

Background and objectives

Thoracic paravertebral blockade is often used as an anesthetic and/or analgesic technique for breast surgery. With ultrasound guidance, the rate of complications is speculated to be lower than when using landmark-based techniques. This investigation aimed to quantify the incidence of pleural puncture and pneumothorax following non-continuous ultrasound-guided thoracic paravertebral blockade for breast surgery.

Methods

Patients who received thoracic paravertebral blockade for breast surgery were identified by retrospective query of our institution’s electronic database over a 5-year period. Data collected included patient demographics, level of block, type and volume of local anesthetic, occurrence of pleural puncture, occurrence of pneumothorax, evidence of local anesthetic toxicity, and patient vital signs. The incidence of block complications, including pleural puncture, pneumothorax, and local anesthetic toxicity, were ascertained.

Results

529 patients underwent 2163 thoracic paravertebral injections. Zero pleural punctures were identified during block performance; however, two patients were found to have a pneumothorax on postoperative chest X-ray (3.6 per 1000 surgeries, 95% CI 0.5 to 13.6; 0.9 per 1000 levels blocked, 95% CI 0.1 to 3.3). There were no cases of local anesthetic systemic toxicity or associated lipid emulsion therapy administration.

Conclusions

Pneumothorax following non-continuous ultrasound-guided thoracic paravertebral block using a parasagittal approach is an uncommon occurrence, with a similar rate to pneumothorax following breast surgery alone.

In Utero Restoration of Hindbrain Herniation in Fetal Myelomeningocele as Part of Prenatal Regenerative Therapy Program at Mayo Clinic

OBJECTIVE

To assess our initial experience with prenatal restoration of hindbrain herniation following in utero repair of myelomeningocele (MMC).

PATIENTS AND METHODS

Three consecutive patients with prenatally diagnosed MMC (between January 1, 2018 and September 30, 2018) were managed with open in utero surgery. As per institutional review board approval and following a protocol designed at the Mayo Clinic Maternal & Fetal Center, fetal intervention was offered between 19 0/7 and 25 6/7 weeks of gestation. Prenatal improvement of hindbrain herniation was the declared restorative end point. Obstetrical and perinatal outcomes were also assessed.

RESULTS

Diagnosis of MMC was confirmed upon referral between 20 and 21 weeks' gestation by using fetal ultrasound and magnetic resonance imaging. In all cases reported here, the spinal defect was lumbosacral with evidence of hindbrain herniation. Open in utero MMC repair was performed between 24 and 25 weeks' gestation with no notable perioperative complications. Postprocedure fetal magnetic resonance imaging performed 6 weeks after in utero repair documented improvement of hindbrain herniation. Deliveries were at 37 weeks by cesarean section without complications. Most recent postnatal follow-ups were unremarkable at both 11 months (baby 1) and 3 months of age (baby 2), with mild ventriculomegaly. Antenatal and postnatal follow-up of baby 3 at 1 month of age was also unremarkable.

CONCLUSION

Our study highlights the prenatal restoration of hindbrain herniation following in utero MMC repair in all cases presented here as an example of a prenatal regenerative therapy program in our institution.

Need for additional anesthesia after single injection spinal analgesia for labor: a retrospective cohort study

BACKGROUND

There is little information about the use and efficacy of single injection spinal blocks for labor analgesia; specifically, how frequently subsequent analgesia or anesthesia is needed. This study determined how frequently an additional anesthetic intervention was needed in women who received single injection spinal analgesia.

METHODS

This retrospective study examined electronic medical records to find all single injection spinal analgesic blocks for labor analgesia over a 14-year (2003-2016) period. Patient and block characteristics and patient outcomes were recorded. The primary outcome was need for an additional anesthetic intervention following single injection spinal for labor analgesia.

RESULTS

Four-hundred-and-twenty-eight patients received single injection spinal blocks for labor and 60 (14.0%) needed an additional anesthetic either for labor analgesia (n=49) or an unexpected procedure (n=11). Two of these (0.5%) required general anesthesia. Parity of zero (nulliparous), a low cervical dilation at the time of the spinal injection, and induction of labor status, were associated with an increased risk of needing an additional anesthetic intervention.

CONCLUSIONS

This retrospective review provides evidence that single injection spinal anesthesia may be used for multiparous women with spontaneous labor and more advanced cervical dilation.

Fetoscopic Therapy for Severe Pulmonary Hypoplasia in Congenital Diaphragmatic Hernia: A First in Prenatal Regenerative Medicine at Mayo Clinic

OBJECTIVE

To introduce the prenatal regenerative medicine service at Mayo Clinic for fetal endoscopic tracheal occlusion (FETO) care for severe congenital diaphragmatic hernia (CDH).

PATIENTS AND METHODS

Two cases of prenatal management of severe CDH with FETO between January and August 2017 are reported. Per protocol, FETO was offered for life-threatening severe CDH at between 26 and 29 weeks' gestation. Regenerative outcome end point was fetal lung growth. Gestational age at procedure and maternal and perinatal outcomes were additional monitored parameters.

RESULTS

Diagnosis by ultrasonography of severe CDH was based on extremely reduced lung size (observed-to-expected lung area to head circumference ratio [o/e-LHR], eg, o/e-LHR of 20.3% for fetus 1 and 23.0% for fetus 2) along with greater than one-third of the liver herniated into the chest in both fetuses. Both patients underwent successful FETO at 28 weeks. At the time of intervention, no maternal or fetal complications were observed. Postintervention, fetal lung growth was observed in both fetuses, reaching an o/e-LHR of 62.7% at 36 weeks in fetus 1 and 52.4% at 32 weeks in fetus 2. The balloons were removed successfully at 35 weeks and 4 days by ultrasound-guided puncture in the first patient and at 32 weeks and 3 days by ex utero intrapartum therapy-to-airway procedure in the second patient. Postnatal management followed standard of care with patch CDH therapy. At discharge, one patient was breathing normally, whereas the other required minimal nasal cannula oxygen support.

CONCLUSION

The successful launch of the first fetoscopic therapy for CDH at Mayo Clinic reveals its feasibility and safety, with early signs of benefit documented by fetal lung growth and reversal of severe pulmonary hypoplasia.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: G170062.

Anesthetic management of two parturients with cerebral palsy and prior selective dorsal rhizotomy

Selective dorsal rhizotomy is a surgical spine procedure used to reduce spasticity in patients with upper motor neuron dysfunction caused by conditions such as cerebral palsy. The optimal anesthetic approach for obstetric patients who have undergone a selective dorsal rhizotomy is unknown. The use and efficacy of neuraxial anesthesia in these patients has not been described. We describe the use of neuraxial anesthesia in two patients with prior selective dorsal rhizotomy. Unless contraindicated for other reasons, a neuraxial anesthetic approach appears to be an effective option in patients with a history of a selective dorsal rhizotomy.

Continuous Posterior Lumbar Plexus Nerve Block Versus Periarticular Injection with Ropivacaine or Liposomal Bupivacaine for Total Hip Arthroplasty: A Three-Arm Randomized Clinical Trial

BACKGROUND

Debate surrounds the issue of whether peripheral nerve blockade or periarticular infiltration (PAI) should be employed within a contemporary, comprehensive multimodal analgesia pathway for total hip arthroplasty. We hypothesized that patients treated with a continuous posterior lumbar plexus block (PNB) would report less pain and consume less opioid medication than those treated with PAI.

METHODS

This investigator-initiated, independently funded, 3-arm randomized clinical trial (RCT) performed at a single high-volume institution compared postoperative analgesia interventions for elective, unilateral primary total hip arthroplasty: (1) PNB; (2) PAI with ropivacaine, ketorolac, and epinephrine (PAI-R); and (3) PAI with liposomal bupivacaine, ketorolac, and epinephrine (PAI-L) using computerized randomization. The primary outcome was maximum pain during the morning (06:00 to 12:00) of the first postoperative day (POD) on an ascending numeric rating scale (NRS) from 0 to 10. Pairwise treatment comparisons were performed using the rank-sum test, with a p value of <0.017 indicating significance (Bonferroni adjusted). A sample size of 150 provided 80% power to detect a difference of 2.0 NRS units.

RESULTS

We included 159 patients (51, 54, and 54 patients in the PNB, PAI-R, and PAI-L groups, respectively). No significant differences were found with respect to the primary end point on the morning of the first POD (median, 3.0, 4.0, and 3.0, respectively; p > 0.033 for all). Opioid consumption was low and did not differ across groups at any intervals. Median maximum pain on POD 1 was 5.0, 5.5, and 4.0, respectively, and was lower for the PAI-L group than for the PAI-R group (p = 0.006). On POD 2, maximum pain (median, 3.5, 5.0, and 3.5, respectively) was lower for the PNB group (p = 0.014) and PAI-L group (p = 0.016) compared with the PAI-R group. The PAI-L group was not significantly different from the PNB group with respect to any outcomes: postoperative opioid use including rescue intravenous opioid medication, length of stay, and hospital adverse events, and 3-month follow-up data including any complication.

CONCLUSIONS

In this RCT, we found a modest improvement with respect to analgesia in patients receiving PNB compared with those receiving PAI-R, but not compared with those who had PAI-L. Secondary analyses suggested that PNB or PAI-L provides superior postoperative analgesia compared with PAI-R. For primary total hip arthroplasty, a multimodal analgesic regimen including PNB or PAI-L provides opioid-limiting analgesia.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Velamentous Umbilical Cord Insertion and Ruptured Fetal Vessel: A Cause of Fetal-Maternal Hemorrhage: A Case Report

BACKGROUND

Fetal hemorrhage is rare but can result in rapid fetal compromise. Abnormally located fetal vessels within the membranes increase the risk for their rupture and subsequent hemorrhage. The classic example of this is vasa previa.

CASE

We present a case of acute fetal hemorrhage resulting from a ruptured fetal vessel. During induction of labor, significant fetal heart rate deceleration occurred, coinciding with acute vaginal bleeding and amniotomy. A depressed, live female neonate was delivered by emergency cesarean section. Examination of the placenta revealed a velamentous cord insertion and a ruptured fetal vessel coursing through the chorioamniotic membranes. Neonatal resuscitation included red blood cell transfusion for hypotension and low hematocrit. The neonate made a full recovery.

CONCLUSION

Acute fetal hemorrhage from the rupture of aberrant fetal vessels often coincides with rupture of membranes. Identifying ruptured fetal vessels abnormally coursing through the chorioamniotic membranes on examination of the placenta provides supporting evidence for suspected fetal hemorrhage.

A rare combination of undiagnosed hypertrophic cardiomyopathy revealed by intraoperative anaphylaxis resulting in acute left ventricular outflow obstruction and cardiac arrest

A 75-year-old female presented for left total hip reimplantation and suffered pulseless electrical activity arrest upon lateral positioning and administering vancomycin. Resuscitation was achieved according to Advanced Cardiac Life Support protocol. Post-event echocardiography showed hypertrophic cardiomyopathy with asymmetrical septal thickening, an under-filled left ventricle, dynamic left ventricular outflow obstruction, and severe mitral regurgitation related to systolic anterior motion of the mitral valve. Laboratory analysis showed a tryptase level of 209 ng/mL. After multispecialty evaluation, it was concluded that the patient's arrest was due to vancomycin anaphylaxis in the setting of previously undiagnosed hypertrophic cardiomyopathy leading to acute left ventricular outflow tract obstruction. After medical optimization of the patient's cardiomyopathy and an evaluation of potential intraoperative allergic triggers, the patient underwent a successful hip reimplantation without incident. This case presents a novel combination of events leading to intraoperative cardiac arrest. Rapid identification and an understanding of the cause(s) of cardiac arrest in this setting are critical for effective perioperative care.

Maternal anesthesia for fetal surgery

This article describes the anesthetic management of pregnant women undergoing fetal surgery. Discussion includes general principles common to all fetal surgeries as well as specifics pertaining to open fetal surgery, minimally invasive fetal surgery, and ex utero intrapartum therapy (EXIT) procedures.

Needle echogenicity in sonographically guided regional anesthesia: blinded comparison of 4 enhanced needles and validation of visual criteria for evaluation

OBJECTIVES

Needle visualization is important for sonographically guided regional anesthesia procedures. Needle characteristics that improve needle visualization are therefore important to anesthesiologists. This study compared several echogenic needle designs by defining characteristics of needle echogenicity and assessing regional anesthesiologist preferences for these characteristics across various needle angles.

METHODS

Twelve blinded regional anesthesiologists graded 5 randomized block needles (1 nonechogenic control and 4 echogenic) on 4 predefined characteristics (overall brightness of the needle, overall clarity of the needle, brightness of the needle tip, and clarity of the needle tip). In-plane needle images in a gel phantom were obtained at 4 needle angles (15°, 30°, 45°, and 60°). Participants rated specific needle characteristics for each needle at each angle and then ranked their overall needle preferences.

RESULTS

Significant differences in all 4 needle characteristics were found across needle types (P< .01). Clarity of the needle tip was significantly associated with overall needle rank (P = .009). Other needle visualization characteristics were not significantly correlated with needle rank. The SonoPlex Stim needle (Pajunk Medical Systems, Tucker, GA) was rated highest in all 4 predefined needle characteristics as well as overall needle rank.

CONCLUSIONS

This study shows that anesthesiologists prefer certain visual characteristics of needles used in sonographically guided regional anesthesia procedures. Specifically, needle tip clarity most closely predicted clinician needle preferences. These results support the idea that all echogenic needle designs do not uniformly enhance needle visualization. Further studies are needed to determine whether needles with superior tip clarity predict not only clinician preferences but also improved sonographically guided regional anesthetic outcomes.

Autonomic cardiovascular control during a novel pharmacologic alternative to ganglionic blockade

The purpose of this study was to compare ganglionic blockade with trimethaphan (TMP) and an alternative drug strategy using combined muscarinic antagonist (glycopyrrolate, GLY) and alpha-2 agonist (dexmedetomidine, DEX). Protocol 1: incremental phenylephrine was administered during control and combined GLY-DEX, or control and TMP on two control combined GLY and DEX or TMP infusion on two randomized days. Protocol 2: muscle sympathetic nerve activity (MSNA) and the baroreflex MSNA relationship was determined before and after GLY-DEX. Blood pressure was higher with GLY-DEX (99+/-3 mm Hg) and lower with TMP (78+/-3 mm Hg) relative to control (GLY-DEX: 90+/-2 mm Hg; TMP: 91+/-2 mm Hg; P<0.05). Incremental phenylephrine increased pressure during GLY-DEX (P<0.01 vs control) and TMP (P<0.01 vs control) to a similar degree. Both GLY-DEX and TMP infusion inhibited norepinephrine release (P<0.01 vs control). GLY-DEX inhibited baseline MSNA (P<0.05) and baroreflex changes in MSNA (P<0.01). We conclude that the GLY-DEX alternative drug strategy can be used as a reasonable alternative to pharmacologic ganglionic blockade to examine autonomic cardiovascular control.

Alternative to ganglionic blockade with anticholinergic and alpha-2 receptor agents

The ganglionic blocking agent trimethaphan (TMP) is no longer produced. Therefore, a need exists for alternative pharmacological approaches to investigate baroreflex control of the circulation. The aim of the present study was to examine baroreflex-mediated cardiovascular responses during the administration of a muscarinic receptor antagonist (glycopyrrolate; GLY: ) and a selective alpha-2 receptor agonist (dexmedetomidine; DEX: ) and to compare responses to ganglionic blockade with TMP. We hypothesized that combined GLY-: DEX: would inhibit the baroreflex similar to TMP. Ten volunteers participated in two study days and were instrumented with pulse oximeter, nasal cannula, ECG, continuous blood pressure monitoring (Finapres), and I.V. catheter for drug infusions. Each study day consisted of a control condition followed by either combined GLY: -DEX: or TMP on alternating days. A Valsalva maneuver was performed under each condition with every subject and six subjects received bolus phenylephrine (25 mug) during GLY: -DEX: and TMP. Combined GLY: -DEX: increased (P < 0.05) blood pressure (99 +/- 4 mmHg) and heart rate (99 +/- 3 bpm) relative to control condition (BP: 90 +/- 2 mmHg; HR: 64 +/- 3 bpm) and TMP infusion decreased (P < 0.05) blood pressure (79 +/- 3 mmHg) while increasing heart rate (88 +/- 3 bpm). Valsalva maneuver elicited a persistent drop in arterial pressure (no phase IIb recovery) with the absence of a phase IV overshoot during both GLY: -DEX: and TMP conditions. Phenylephrine increased systolic pressure 34 +/- 4 mmHg under GLY: -DEX: and 23 +/- 3 mmHg with TMP (P < 0.05). Heart rate only decreased 1 +/- 2 bpm during GLY: -DEX: and 1 +/- 1 bpm with TMP. Taken together, our results suggest that GLY: -DEX: is a reasonable alternative to TMP for baroreflex inhibition.

Dermatologic Adverse Effects of Lenalidomide Therapy for Amyloidosis and Multiple Myeloma

OBJECTIVES

To examine dermatologic adverse effects of lenalidomide in patients with amyloidosis and multiple myeloma and to determine whether the adverse effects are different when lenalidomide is used alone compared with when it is used in combination with dexamethasone.

DESIGN

Retrospective review of medical records.

SETTING

Tertiary referral center.

PATIENTS

Seventy-five patients with multiple myeloma and 23 patients with amyloidosis participating in clinical trials.

INTERVENTION

In the 75 patients with multiple myeloma, lenalidomide was the treatment in 24 and lenalidomide and dexamethasone in 51. In the 23 patients with amyloidosis, lenalidomide was used alone.

MAIN OUTCOME MEASURES

The frequency, type, severity, and time of onset of all skin eruptions that were temporally related to lenalidomide treatment were recorded.

RESULTS

In the patients with amyloidosis treated with lenalidomide, 10 (43%) had rashes. In the patients with multiple myeloma, rashes occurred in 7 (29%) of those receiving lenalidomide alone and in 15 (29%) of those receiving lenalidomide and dexamethasone. The rashes were characterized as morbilliform, urticarial, dermatitic, acneiform, and undefined. Severe rashes required permanent discontinuation of lenalidomide therapy in 2 patients. In 23 patients (72%), rashes occurred in the first month after therapy was initiated; however, delayed-onset rashes occurred in 9 (28%).

CONCLUSIONS

The prevalence of dermatologic adverse effects in patients receiving lenalidomide was higher in those with amyloidosis than in those with multiple myeloma. The prevalence of skin eruptions was not diminished by the concurrent use of systemic corticosteroids. Most skin eruptions were mild and did not necessitate withdrawal of lenalidomide therapy.