Thomas L. Archer

Like methylene blue, indigo carmine might counteract vasoplegia: hemodynamic evidence obtained with pulse contour analysis

maintenance [4]. Automated induction required 0.9 mg kg−1 of propofol and 1.9 μg kg−1 of remifentanil, followed by administration of atracurium 70 mg to facilitate tracheal intubation after documenting uncomplicated manual ventilation with a large face mask. On first attempt at direct laryngoscopy with a #6 Macintosh blade, the glottic opening was seen and a grade 2 Cormack and Lehane view was noted without laryngeal manipulation. Tracheal intubation was accomplished using a size 8.5 ID cuffed endotracheal tube. During the procedure, a fiberoptic bronchoscope was available in the operating room. Anesthesia duration was 102 minutes. During maintenance, BIS values were maintained between 40 and 60 during 83% of the time (Fig. 3), without any episode of burst suppression. A total of 42 and 40 modifications of propofol and remifentanil concentrations, respectively, were automatically made; no modification was made by the attending anesthesiologist. BIS, systolic blood pressure, heart rate values, and calculated blood concentrations of propofol and remifentanil are shown in Fig. 3. No vasodilator or vasopressor was administered. The macro-adenoma was removed via the transnasal approach. Thirty minutes before the end of surgery, the patient received IV morphine 10 mg for postoperative analgesia. After termination of surgery, the propofol and remifentanil infusions were stopped. Tracheal extubation was performed 7 minutes later, and the patient was able to transfer himself to a specially constructed bed. After 24 hours of postoperative care in the recovery room (as per local practice for all neurosurgical cases), the patient was transferred to the surgical ward. No intraoperative recall was reported. Target-controlled infusion systems for propofol and remifentanil are based on averaged pharmacokinetic models [6,7] derived from healthy volunteers. Our patient was obviously not comparable to the usual population of volunteers. Another approach is to bypass the pharmacokinetic model and to measure the drug effect directly by the electro-cortical activity. Using a dual closed-loop controller, propofol and remifentanil concentrations were continuously adjusted to avoid underdosing (limiting the risk of awareness) or overdosing (allowing a quick recovery). Furthermore, automatic anesthetic drug delivery decreases the workload during the induction phase when the clinical priority is airway management. Occurrence of this disease has almost completely disappeared by the early recognition of developing gigantism at a young age. However, in some developing countries, excessive production of growth hormone still remains undiagnosed.

Electrical velocimetry demonstrates the increase in cardiac output and decrease in systemic vascular resistance accompanying cesarean delivery and oxytocin administration

pain returned again in a few hours to NRS 5 to 6, and it took approximately 5 hours before the pain level was back to NRS 2 to 3. She used this combination for three months with persistent pain reduction. This treatment regimen reduced the pain more than 50% from baseline. Side effects such as a sensation of slight derealization due to the psychotropic effects of both drugs, were mild. Blood pressure was not affected. Furthermore, careful titration of ketamine cream volume and the cannabis cookies is possible so as to achieve an optimal balance between efficacy and psychotropic side effects. Cannabis is available in the Netherlands as a prescription drug. One of the main indications for its use is neuropathic pain [5], for which cannabis is generally seen as acceptable third-line treatment [4]. Cannabinoids are agonists for the central and peripheral cannabinoid receptors, CB1 and CB2, both playing an important role in pain modulation [6,7]. Ketamine acts on the N-Methyl-D-aspartate (NMDA) receptors, which, as with the cannabinoid receptors, are located centrally and peripherally [8]. Besides the NMDA receptors, ketamine acts also on many others, such as opioid, monoaminergic, and muscarinic receptors [9]. Ketamine and cannabis may act synergistically because cross-talk exists and the cannabinoid and the opioid receptor systems also have synergistic interactions [10,11].

Electrical velocimetry elucidates the hemodynamics of hypertension caused by indigo carmine

To the Editor: In a recent letter to the Journal of Clinical Anesthesia, pulse contour analysis was used to observe an increase in systemic vascular resistance (SVR) caused by intravenous (IV) indigo carmine [1]. In this letter the use of electrical velocimetry (a type of impedance cardiography) describes a similar response in another patient. An anxious 34 year old, G11 P10 woman presented in labor for repeat cesarean section. Her medical history and laboratory values were unremarkable. At 09:25 a combined spinal epidural was performed with intrathecal bupivacaine 12 mg, fentanyl 25 μg, and morphine 100 μg. The epidural catheter was never injected. Cutaneous block to cold sensation was achieved to the T5 level, and a vigorous infant was delivered at 09:56. When the patient was informed that surgery would be prolonged due to bladder injury, she became more anxious and she and her husband insisted that she be put to sleep, despite the fact that she felt no pain. Intravenous fentanyl 75 μg, propofol 170 mg, and succinylcholine 120 mg were administered, and at 11:18 the trachea was intubated. Anesthesia was maintained with 70% nitrous oxide in oxygen and midazolam 2.0 mg was administered at 11:22. No potent inhaled agents were used. At 11:30 IV indigo carmine 5 mL was given for visualization of the ureteral orifices at

Unrecognized Uterine Hyperstimulation Due to Oxytocin and Combined Spinal-Epidural Analgesia

The anesthesia resident was called to evaluate a 32-year-old gravida 1 para 0 in labor at term for epidural placement because of severe labor pain at 6–7 cm of cervical dilation. She performed a combined spinal-epidural anesthetic, and the patient received rapid and complete pain relief, which was rapidly followed by fetal bradycardia. The resident treated mild maternal hypotension with vasopressors, left lateral positioning, fluids, and oxygen, but the fetal bradycardia persisted and preparations were made for emergency cesarean section. Uterine hypertonus (“hyperstimulation”) was diagnosed by the obstetric attending prior to cesarean section, and the administration of terbutaline to relax the hypertonic uterus avoided the need for a cesarean section.

A Pregnant Patient with Mitral Stenosis

This case describes a pregnant patient who presented prior to delivery with an unspecified cardiac condition that was determined to be severe mitral stenosis Although a scheduled cesarean section was planned, the patient presented prior to the planned procedure in active labor with uncontrolled pain. Management of this patient, the pathophysiology of mitral stenosis, and considerations relevant to this condition in pregnancy are discussed.

Acute Pulmonary Dysfunction Immediately After Cesarean Delivery Under General Anesthesia

A woman with known von Willebrand (vW) disease type 2b presented with vaginal bleeding at 38 and 2/7 weeks of gestation for repeat cesarean section. Prior to surgery she received exogenous, structurally normal vW factor in the form of Humate-P, which contains both factor 8 and vW factor. She was unintentionally overloaded with fluid prior to the induction of general anesthesia and suffered acute pulmonary dysfunction immediately after delivery, perhaps due to heart failure caused by fluid overload and light anesthesia. Incipient mainstem intubation was ruled out since it is often misdiagnosed as “bronchospasm.” She was treated with diuretics and by deepening the anesthesia and she rapidly recovered. vW disease types 1 and 3 involve an insufficient quantity of structurally normal vW factor, whereas type 2 disease involves structurally abnormal vW factor. DDAVP, which releases stored vW factor from vascular endothelium, should probably not be used in vW disease type 2.

Labor Epidural with Unrecognized Dural Puncture, Causing High Sensory Block, Hypotension, Fetal Bradycardia, and Post-dural Puncture Headache

A healthy parturient had an epidural placed with difficulty which then worked “too well” after placement. Unrecognized dural puncture is common and is more dangerous than a recognized dural puncture since it can lead to a high block, hypotension, fetal hypoxia and bradycardia, and even maternal death. Negative test doses do not rule out the possibility of an accidental dural puncture, and vigilance and eternal skepticism about one’s “epidural” are essential to safe obstetric anesthesia practice. A post-dural puncture headache can be a very disabling complication for an otherwise healthy woman with a new baby to care for. Ultrasound may be helpful for reducing the incidence of accidental dural puncture, but this is unproven.

Jehovah’s Witness with Placenta Previa and Increta for Cesarean Hysterectomy

A 34-year-old woman, gravida 3 para 2, who had undergone two previous classical cesarean sections, was referred at 32 weeks and 6 days estimated gestational age for management of placenta previa. Placenta accreta was suspected and placenta increta was confirmed by magnetic resonance imaging (MRI). The patient was a Jehovah’s Witness who refused allogeneic red blood cell transfusion, but would accept crystalloid and colloid solutions, fresh frozen plasma, cryoprecipitate, factor VIIa, dialysis, and autologous transfusion via a continuous circuit which did not lose its connection with her body, including both acute normovolemic hemodilution (ANH) and intraoperative cell salvage. Extensive preparations were made, including preoperative treatment with erythropoietin, adequate intravenous access, and an arterial line. General anesthesia was used after ANH. Blood loss was minimal and the blood removed by ANH was returned to her in a continuous circuit. Extensive planning and preparation are crucial in these cases.

Super-Morbidly Obese Patient for Elective Repeat Cesarean Section

A 32-year-old woman, gravida 2 para 1, was referred to the University of California San Diego (UCSD) Obstetric Anesthesia consultation service at an estimated gestational age of 36 weeks and 4 days because of super-morbid obesity and a prior history of a failed epidural and severe labor pain. Obese patients can be very challenging and we have found it helpful to have an extensive plan in place for the care of the obese parturient. This “obesity bundle” of interventions involves everything from psychological preparation of and “buy-in” from the patient to the gathering of needed physical devices such as table wideners, positioning ramps, and long epidural needles. Preprocedural ultrasound can be of great value in facilitating neuraxial block placement, and my technique (learned from Jose Carvalho, MD) is described in detail.

Don't forget aortocaval compression when imaging abdominal veins in pregnant patients

A recent review by Gyselaers et al. in this journal1 discussed the role of the abdominal venous system in regulating cardiac output (CO) in pregnancy and speculated that abdominal and pelvic venous congestion may contribute to placental and uterine dysfunction and pre-eclampsia. The authors did not mention, however, the role of compression of the inferior vena cava (IVC) by the gravid uterus in causing uterine venous congestion and uterine ischemia, especially when the patient is in the supine position. Even renal perfusion may be affected by increased intra-abdominal pressure, whether or not the pressure is applied above or below the level of the renal veins2. All of their measurements were taken using the supine position and no comparisons were made of renal venous flow in the lateral and supine positions. We have been intrigued by the possibility that obstruction of the IVC by the gravid uterus and resultant abdominal and pelvic venous congestion might cause poor placental and uterine function and might contribute to pre-eclampsia3,4. The placenta and uterus must function best when they are well perfused and optimal perfusion requires decompressed, low-pressure venous outflow. But how does one know when the uterine veins are decompressed? We have proposed that a new impedance cardiographic technique for measuring CO, known as electrical cardiometry (EC), might be useful for determining when the IVC is unobstructed and, by inference, when uterine venous pressure has been minimized3,4. With this approach, the maximization of CO is used as a marker to identify the maternal position in which the IVC is unobstructed and uterine venous pressure is presumably at its minimum. Figure 1 illustrates how position affects maternal CO (and presumably pelvic venous congestion) at an estimated gestational age of 26 + 3 weeks. This effect of maternal position on CO is well known. What is new is that we may now have an easy-to-apply, non-invasive and continuous means of measuring CO and, by inference, a method of predicting whether or not the pelvic venous system is congested due to an obstructed IVC. In the patients we have studied to date, the full left lateral position usually