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Rotational Thromboelastometry (ROTEM) Delta has been described in several postpartum hemorrhage algorithms, but this device requires pipetting and careful mixing of reagents to initiate the clotting reaction. In contrast, thromboelastography (TEG 6s) and the Quantra devices operate utilizing an automated pre-mixed cartridge that only requires a blood sample to start the clot strength analysis. We compared the correlation between 3 point of care viscoelastic testing (POCVT) devices to laboratory Clauss fibrinogen and platelets, their inter-device correlation, and the total running time difference between Quantra and ROTEM. A high correlation was noted between the Clauss fibrinogen and the fibrinogen parameters from ROTEM (r = 0.76-0.84, P 0.0001), TEG6s (r = 0.71, P 0.0001) and Quantra (r = 0.72, P = 0.0001). A moderate correlation between laboratory platelets and the ROTEM (r = 0.54;0.45, P 0.0001; P = 0.0013) and Quantra (r = 0.66, P = 0.0001) parameters was noted. The inter-device correlation showed to be high when comparing the fibrinogen parameters of TEG6s and Quantra to that of ROTEM (r = 0.88 and 0.74, P 0.0001, respectively). In contrast, a moderate correlation was noted between the platelet parameters of Quantra and ROTEM (r = 0.51, p = 0.0036). The Quantra device resulted 20.9 min (95% CI -0.2 to 4.7, P = 0.07) faster than the ROTEM if the warming and pipetting of reagents of the latter were considered. All the POCVT devices demonstrated a high correlation to laboratory Clauss fibrinogen, making each beneficial for the early recognition and management of hypofibrinogenemia.

Objective: To study the photoplethysmographic (PPG) waveforms of different locations (ear and finger) during lower body negative pressure (LBNP) induced hypovolemia. Then, to determine whether the PPG waveform can be used to detect hypovolemia during the early stage of LBNP. Approach: 36 healthy volunteers were recruited for progressive LBNP induced hypovolemia, with an endpoint of -60 mmHg or development of hypoperfusion symptoms, whichever comes first. Subjects tolerating the entire protocol without symptoms were designated as high tolerance (HT), while symptomatic subjects were designated as low tolerance (LT). Subjects were monitored with an electrocardiogram, continuous noninvasive blood pressure monitor (CNAP), and two pulse oximetry probes, one on the ear (Xhale) and one the finger (Nellcor). Stroke volume (SV) was measured non-invasively utilizing NICOM (Cheetah Medical). The waveform morphology was analyzed using novel PPG waveforms indices, including phase hemodynamic index (PHI) and amplitude hemodyamaic index (AHI) and were evaluated from the ear PPG and finger PPG at different LBNP stages. Main Results: The PHI, particularly the phase relationship between the second harmonic and the fundamental component of the ear PPG denoted as 〖∇φ〗_2, during the early stage of LBNP (-15 mmHg) in the HT and LT groups is statistically significantly different (p value=0.0033) with the area under curve 0.81 (CI: 0.616-0.926). The other indices are not significantly different. The 5 fold cross validation shows that 〖∇φ〗_2 during the early stage of LBNP (-15 mmHg) as the single index could predict the tolerance of the subject with the sensitivity, specificity, accuracy and F1 as 0.771±0.192, 0.71±0.107, 0.7±0.1 and 0.771±0.192 respectively. Significance: The ear’s PPG PHI which compares the phases of the fundamental and second harmonic has the potential to be used as an early predictor of central hypovolemia.

A 35-year-old parturient with antiphospholipid syndrome and a working diagnosis of hemolysis, elevated liver enzyme, and low platelets (HELLP) underwent a cesarean delivery 9 hours after receiving heparin. Her preoperative activated partial thromboplastin time and rotational thromboelastometry (ROTEM) intrinsic pathway (INTEM) clotting time were 120 and 1870 seconds, respectively. Fresh frozen plasma was administered for heparin neutralization. The ROTEM INTEM/heparinase assay (HEPTEM) ratio can help confirm heparin neutralization and guide intraoperative transfusion management.

1. Spondylolysis is a defect in the pars interarticularis of the vertebra. This defect usually involves the L5 vertebra (95%) [1]. “Spondylo” derives from the Greek word for vertebra, and “lysis” refers to a defect [2] (see Fig. 148.1). 2. Spondylolisthesis is defined as a forward slip of the vertebrae relative to the one below with or without an accompanying pars defect. “Olisthesis” is the Greek word for slippage [2]. The displacement of the vertebra could be secondary to one of the following: a congenital defect, spondylolysis (isthmic spondylolisthesis), degeneration of facet joints and/or intervertebral disk degeneration (degenerative spondylolisthesis), trauma, or pathologic [1]. 3. Only a subset of patients with spondylolysis will have progression to spondylolisthesis if bilateral defects are present [3].

A healthy 25-year-old G3P2002 patient at 38-week gestation was referred to the high-risk obstetric anesthesia service due to the presence of abnormal placentation. Her past surgical history included 2 previous cesarean deliveries. The ultrasound examination was suspicious for a complete anterior placenta previa with multiple placental lakes, which looked even more likely after magnetic resonance imaging (MRI).

The obstetrical team (OB) calls the anesthesia resident to inform him that one of the laboring patients will have a cesarean delivery for failure to progress. The anesthesia resident calls his attending: “I am calling to discuss our 24-year-old G1P0 parturient in labor room 8 who will be having a cesarean delivery for failure to progress. The patient’s medical history is significant only for obesity. She denies any surgeries in the past. Her airway examination reveals a Mallampati 3, with good mouth opening, normal thyromental distance, full range of motion, and a short, thick neck. We placed her epidural this morning, and I have been asked to give additional medication (top-up) three times since then.

Rarely, epidural catheters may fracture upon removal or insertion. Understanding some of the mechanical properties of epidural catheters, such as their tensile strength and how external factors (including temperature) can influence their strength, will aid physicians in making decisions if faced with an entrapped catheter. In the present study, we evaluated the impact in tensile strength when catheters are exposed to 37 ± 1°C, after the removal of the inner metal coil and after the injection of sterile saline through the catheter.We analyzed the tensile strength of a total of 120 catheters (19-gauge) from 3 different brands and materials. The reinforced epidural catheters were affixed to opposing, specially designed tensile test fixtures and then installed in an Applied Test System tensile test apparatus. We evaluated the strength of 10 catheters from different brands and materials for each of the following variables: at room temperature (control group), after the removal of the inner wire present in all the flexible catheters tested, injection of normal saline, and at 37 ± 1°C.When compared with their control groups, the Arrow catheter (2.85 kg) was shown to be superior to B-Braun (2.17 kg; P0.0001) and Smith catheters (2.33 kg; P0.0005). No statistical difference was noted between the Smith and B-Braun catheters (P = 0.39). When comparing catheters after wire removal against their respective control group, no statistical difference was noted. A decrease in tensile strength was noted in the B-Braun catheters (1.53 kg) when tested at 37°C (P ≤ 0.0001). In contrast, the Smith and the Arrow catheters did not show a statistically significant change when tested at 37°C (P = 1.0 and P = 0.063, respectively). After the injection of normal saline, the Arrow (2.33 kg) and the B-Braun (1.58 kg) catheters showed a decrease in tensile strength (P = 0.0010 and P = 0.0001, respectively).The current recommendation of injecting saline through an entrapped catheter resulted in a decrease in tensile strength of the Arrow and B-Braun catheters. A decrease in tensile strength also was noted in the B-Braun catheters when tested at 37°C. There is no benefit, at least in terms of tensile strength, in removing the wire or inner coil from any of the tested brands. The Smith catheter was the most resilient, showing no decrease in tensile strength at 37°C and after the injection of normal saline when compared with control.

Coagulation is an organized and well-orchestrated process that depends on the intrinsic balance between procoagulants, anticoagulants, and fibrinolytic systems. During pregnancy, this balance is affected in various ways and becomes more critical due to the physiologic changes and obligate hemorrhage after delivery. In some instances, this equilibrium will be disrupted. In this article, we describe the anesthetic implications of bleeding disorders, thrombophilias, and anticoagulation for the safe management of the parturient, with an emphasis on how this impacts decision-making by the anesthesiologist.