Photoplethysmography (PPG) has been extensively used for pulse oximetry monitoring in perioperative and intensive care. However, some components of PPG signal have been employed for other purposes, such as non-invasive hemodynamic monitoring. Perfusion index (PI) is derived from PPG signal and represents the ratio of pulsatile on non-pulsatile light absorbance or reflectance of the PPG signal. PI determinants are complex and closely interlinked, involving and reflecting the interaction between peripheral and central hemodynamic characteristics, such as vascular tone and stroke volume. Several studies have shed light on the interesting performances of this variable, especially for hemodynamic monitoring in perioperative and intensive care.

In the first section of this chapter the physiological and pathophysiological determinants of PI are exposed, along with relevant measuring techniques and potential limitations. Second, the existing data concerning the usefulness of PI in different clinical settings are presented and discussed. Lastly, we review known perspectives and identify new perceptions concerning the use of PI that should be explored regarding its utilization.

The most important indication for electroencephalography (EEG) in critically ill patients is to evaluate fluctuating or persistently abnormal mental status (or other focal neurological deficits) that cannot otherwise be explained. Commonly, these symptoms are a manifestation of physiological diffuse cerebral dysfunction (encephalopathy), or they may be due to seizure activity without apparent clinical manifestations. Such “nonconvulsive” seizures (NCS), that may only be detected by EEG, occur in at least 8–10% of critically ill patients. Continuous or frequent NCS is called nonconvulsive status epilepticus (NCSE), and may result in secondary neurological injury, including neuronal death or alteration of neuronal networks. Left untreated, NCSE can become increasingly refractory to treatment. EEGs may be indicated in acute brain injury to detect seizure activity. They are useful in monitoring the depth of anesthesia and in the management of refractory status epilepticus. EEGs may also be used in the intensive care unit to characterize paroxysmal clinical events and in prognostication after cardiac arrest or determining brain death.

Ultrasonography is a safe, relatively inexpensive, and portable imaging modality. With the increasing availability of mobile, portable, and pocket-sized ultrasound machines, point-of-care transthoracic echocardiography has become a bedside tool to serve in medical emergencies and in peri-operative settings to assess the hemodynamically unstable obstetric patient in a timely fashion. In managing obstetric critical illness, some characteristics of pregnant women facilitate a focused cardiac examination, including anterior and left lateral displacement of the heart, spontaneous ventilation, and familiarity with ultrasound use. It supplements the physical examination, basic investigations, and aids in the diagnosis of significant cardiac pathology. While many acronyms exist, such as bedside echocardiography, point-of-care echocardiography, hand-held echocardiography, or goal-directed echocardiography, national and international scientific bodies have agreed on the terminology “focused cardiac ultrasound” or FoCUS. This chapter provides an overview of the definition, techniques, and diagnostic aims of a FoCUS examination and its clinical applications in obstetric cardiac disease. The chapter concludes by summarizing certification standards and training requirements.

Genetic disorders commonly present or show severe manifestations early in life and in reproductive-age women. The impacts of such disorders in pregnancy are complex, often involving both mother and fetus. This chapter provides an overview of key concepts in genetics, focusing on the patterns of inheritance of monogenic disorders. The features and management of several common disorders are discussed, including alpha-1 antitrypsin deficiency, autosomal dominant polycystic kidney disease, Charcot Marie Tooth disease, Ehlers Danlos syndrome, Loeys-Dietz syndrome, glucose-6-phosphate dehydrogenase deficiency, Down syndrome, Turner syndrome, and mitochondrial disorders with a focus on management considerations, relevant for the practice of the obstetric anesthesiologist.

Many inherited conditions result from disorders of intermediary metabolism. Many more are discovered annually using advanced gene sequencing and other tools. These diseases cause symptoms because of the accumulation of precursors, absence of the final product, excessive toxic intermediaries, or a combination of all three mechanisms. Many are fatal in childhood, but some are compatible with adult life and pregnancy. A better understanding of the enzymatic deficiencies and new technologies have made recombinant enzyme replacement therapy possible. Along with early diet manipulation, current management allows many patients to live relatively normal lives. Because fertility may not be affected, some of these conditions will be encountered by the anesthesiologist. This chapter describes diseases caused by certain enzyme deficiencies and the by-products that cause symptoms. Some are exacerbated by pregnancy and the stress of labor and delivery. The anesthesiologist plays an essential role in reducing physiologic stress and avoiding triggering agents and routines that cause severe metabolic derangements or cardiopulmonary decompensation. The final portion of the chapter describes the most recent advances in the prevention and treatment of malignant hyperthermia in pregnancy, discussing the impact on mother and baby.

Symptoms relating to the musculoskeletal system are among the most common complaints registered by pregnant women. The maternal axial skeleton is subjected to considerable gestational changes and stresses; congenital and acquired skeletal anomalies may impact both the process and outcome of gestation and labor. The most common anomaly is scoliosis, arising either in the idiopathic form or from an underlying neuromuscular disorder. Other less common conditions include symptomatic lumbar disc herniation, ankylosing spondylitis, spondylolysis, and spondylolisthesis. Most scoliotic patients will experience pregnancy, labor, and delivery with a similar incidence of complications as the general population. However, within the population of scoliotic parturients, there is a subpopulation at higher risk for morbidity and mortality. These patients include those with scoliosis resulting from neuromuscular disorders and severe restrictive pulmonary disease complicated by pulmonary hypertension. A multidisciplinary team approach best serves these patients. The obstetric and anesthetic management of patients with less common and less extreme vertebral syndromes is guided by individual case characteristics.

Hematological disorders are a heterogeneous group that may be inherited or acquired. During pregnancy the condition may improve, stabilize, or deteriorate due to normal physiological changes. Major risks in women are hemorrhage or thrombosis; inherited conditions may affect fetus as well. A multidisciplinary team is required to manage the pregnancy, delivery, and postpartum. This chapter reviews and summarizes the literature on maternal and fetal outcomes with a focus on anesthetic considerations and publications.

During your obstetric call duty in a tertiary hospital center, you receive a telephone call from a colleague at an external center for an incidental isolated platelet count of 69 × 109/L in a 22-year-old primigravida with a singleton pregnancy at 24+3 weeks’ gestation by early dating sonography. The full/complete blood count (FBC/CBC) was performed to follow up on iron-deficiency anemia. Fetal activity is normal.

The focus of this chapter is to discuss a multidisciplinary approach to maternal-fetal patients undergoing minimally invasive (shunt or fetoscopic) procedures, open fetal surgery, or the ex-utero intrapartum therapy (EXIT) procedure. The team requires a diverse group of personnel. We will discuss the nature of this team and the pertinent aspects of the preoperative, intraoperative, and postoperative phase of care for the maternal-fetal patient. The preparation required for the team members providing care for these patients as well as the long-term follow-up and research aspects are outlined. Comprehensive expert care for these interventions requires administrative, institutional, research, and philanthropic support.

Sacrococcygeal teratoma (SCT) is a common tumor of the neonatal period. Prenatal diagnosis of SCT carries a high mortality rate because of the potential for high output heart failure and hydrops. Tumors can also rupture, leading to severe anemia and death. The mother’s health is also at risk if maternal mirror syndrome develops. Prenatal evaluation includes high resolution ultrasound, fetal echocardiography, and magnetic resonance imaging. Pregnancy management includes frequent assessment of the tumor size, growth, and the effects on the fetal cardiovascular system. Treatment options depend on the tumor characteristics and cardiac function, as well as maternal health and support. Fetal therapy aims to debulk or devascularize the tumor, thereby alleviating high output failure and minimizing the risk of spontaneous rupture and hemorrhage. Decisions regarding a symptomatic fetus with SCT may include prenatal intervention or early delivery. Anesthetic management of fetal treatment for SCT is tailored to the mode of therapy chosen; this may include a minimally invasive approach, in-utero surgery, or an EXIT procedure. The nuances of management of this condition center on understanding of the pathophysiology of a hydropic fetus as a result of the SCT and being prepared for resultant cardiovascular instability and massive hemorrhage.

Total anomalous pulmonary venous return is a rare disorder characterized by the lack of direct connection of the pulmonary veins to the left atrium; instead, the pulmonary veins connect either directly to the right atrium or indirectly via a vein connected to the right atrium. This results in oxygenated blood ultimately draining into the right atrium and mixing with deoxygenated blood, necessitating a right-to-left atrial shunt to survive. Although it can be an isolated defect, in approximately two-thirds of cases total anomalous pulmonary venous return is associated with complex cardiac defects and frequently with heterotaxy syndrome, an embryologic disruption of right and left laterality of the thoracic and abdominal organs. Children with heterotaxy and total anomalous pulmonary venous return have even higher rates of early and late morbidity and mortality. This chapter details the perioperative management of a patient with recurrent pulmonary venous stenosis and intestinal malrotation requiring urgent abdominal surgery and outlines the appropriate management strategies for high-risk patients with this physiology.

Critical aortic stenosis is defined as the presence of severe aortic valve stenosis with systemic perfusion that is dependent on right ventricular output through a patent ductus arteriosus. Critical aortic stenosis is not defined by an absolute valve area or gradient because in patients with ventricular dysfunction (either systolic or diastolic) it may exist with larger valve areas and gradients may be underestimated. The degree of left ventricular hypertrophy in these neonates, though not as severe as in older patients, still exists, and the ventricle may be dilated and poorly contractile. This chapter discusses available interventions for the neonate with critical aortic stenosis: surgical aortic valvotomy vs. balloon aortic valvuloplasty in the cardiac catheterization laboratory. Preparation for care of the critically ill neonate in the cardiac catheterization laboratory is outlined, as well as perioperative and anesthetic management considerations for a neonate with critical aortic stenosis.