The fog of Alzheimer’s is a commonly used metaphor, and I think it’s a pretty good one. It refers to the loss of mental acuity, disorientation, and forgetfulness that are common in Alzheimer’s. But one aspect of the metaphor that is not emphasized is that like the fog bank on the ocean, the fog of Alzheimer’s can come and go. It does for me. Sometimes there is an obvious cause such as running a fever, getting too tired, or having a second glass of wine. On the day after I got my second Covid-19 vaccination I was not mentally sharp and had trouble concentrating despite not having any other side effects. Once or twice a week on first awakening in the morning, I think I am in my childhood bedroom. It only takes a few seconds to get reoriented, and it actually is a pleasant rather than scary experience. Sometimes the fog comes in for no apparent reason, lasts a few minutes or a few hours, and then goes away. I wonder what is behind these mysterious, seemingly unprovoked but temporary episodes of cognitive impairment.

• Sickle cell disease (SCD) is caused by an autosomal recessive mutation in the β-globin chain of hemoglobin A (HbA), causing the mutated hemoglobin S (HbS). In a vaso-occlusive crisis (VOC), sickled red blood cells (RBCs) increase the viscosity of blood and cause microvascular occlusion, contributing to hypoxia, acidosis and further sickling. The clinical manifestations of SCD are diverse and are related to chronic hemolysis with periodic episodes of vascular occlusion that can affect nearly every organ system.

• Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused the pandemic declared in March 2020. While many of the manifestations (i.e., acute respiratory distress syndrome [ARDS]) are similar to other severe respiratory viruses, there is an increasing number of specific therapeutics found to be effective in combating coronavirus disease 2019 (COVID-19). As data emerge on the optimal treatment of COVID-19, the recommendations in this chapter are based on the current consensus from large global health and infectious disease authorities but are subject to evolution of the evidence.

Alpine birds face many challenges to live in habitats characterized by low temperatures, high winds, short growing seasons and delayed breeding schedules. Breeding in alpine environments is always a race against time due to the shortened egg laying period and frequent storms that may result in delayed development or reproductive failure. Since daily temperatures in the alpine zone can range from below freezing to >450C, developing embryos may require cooling as well as heating to maintain homeothermy. To cope with such conditions, birds breeding in alpine habitats have developed physiological, morphological and behavioural adaptations, and have adopted a slower lifestyle where they may produce fewer offspring each year compared to populations at low elevations, but may live longer. In the northern hemisphere, only a few birds live exclusively in the alpine zone, with many mountain species breeding in both alpine and lower elevation habitats, while in the Southern Andes, most alpine birds breed exclusively above the treeline. In summary, there may be high ecological costs to living in open habitats at high elevations. However, alpine birds likely experience lower levels of interspecific competition, habitat degradation and parasites and diseases than birds living at lower elevations.

Sudden infant death syndrome (SIDS) is multifactorial, associated with inadequate cardiac, breathing, autonomic and/or arousal control. Although cases are usually found collapsed in the early hours of the morning, collapse can occur in daytime. If resuscitation is successful, these infants may die later (delayed SIDS). In these circumstances, hypoxic ischaemic injury to vital organs, including the central nervous system will likely develop: haemorrhages (subdural (SDH), intradural, subgaleal, subarachnoid and/or brain), oedema, spinal and/or retinal haemorrhages (RH). The SDH and encephalopathy are well described in young infants dying of natural causes, especially following successful advanced resuscitation. Infants who develop the triad of SDH, RH, and encephalopathy share many epidemiological features with infants dying of SIDS: age, male sex, prematurity, small for gestational age, young mothers, multiple births, high parity, low socioeconomic status, smoking during pregnancy, minor respiratory infections. Hence, it seems reasonable to hypothesise that there is an overlap between some features in SIDS and SBS, and that the latter may correspond to a resuscitated SIDS.

The high-medieval demographic and economic growth in which fishers and their customers shared had detectable environmental consequences. Prevailing agricultural practices plus increased human and other wastes damaged river systems and polluted both flowing and still waters. Contemporaries were aware of some such effects; others emerge only in modern scientific archaeology. Rulers and others blamed perceived declines in the quantity and quality of fish on overfishing. Present-day studies of long-running assemblages of fish remains detect local depletion of favoured varieties and shrinking average size of more common species. Some fishes (eel) and some fisheries (for herring) of previously limited importance increased their contribution to European diets. An exotic species, common carp, hitherto present in Europe only in the lower Danube, spread westwards into waters made warmer and siltier by human activities. In large thirteenth-century assemblages (but with regional variations), more accessible herring, eel, codfishes, and small cyprinids become dominant. Not all change had human origin; natural dynamics also played a role. High medieval centuries saw the crest, then decline, of climatic warming, with concomitant regional differences in precipitation, seasonality, riverine and estuarine hydrology, and even shifts in stratification and water chemistry of the Baltic. Changed habitats let heat-tolerant fishes spread west, while a herring-dominated regime in the Baltic peaked and slowly yielded to greater presence of cod. Knowingly or not, humans and animals had to adapt.

A 33-year-old nulligravid woman is undergoing hysteroscopic removal of a 5 cm FIGO type 1 submucosal myoma due to heavy menstrual bleeding and mild anemia. She is otherwise in good health and has no significant medical or surgical history. She is not on any medications and denies drug allergy. The patient receives general anesthesia without difficulty. The procedure commences with use of a fluid management system and a bipolar resectoscope to remove myoma fragments. Approximately 30 minutes into the surgery, the anesthesiologist becomes concerned due to sudden decrease of oxygen saturation to 87%. The total fluid deficit is approaching 2300 mL. The anesthesiologist administers intravenous (IV) furosemide and asks the surgeon to terminate the procedure. Several minutes later, oxygen saturations increase to 92%. The patient is awakened from anesthesia and proceeds to the recovery room in a stable condition.

Key Learning Points

1. 1. Drowning is a leading global killer of children and young adults.

2. 2. Outcomes from drowning are uncertain, principally determined by the time of cerebral anoxia, and not the extent of pulmonary aspiration and soiling.

3. 3. Trauma should be considered as a potential cause or consequence of drowning; hence, protective C-spine measures should be considered.

4. 4. Rescue breaths should be administered to both adult and paediatric drowned patients with or without spontaneous circulation.

5. 5. Hypothermia is commonplace in drowned patients and should be managed with active rewarming to 34°C.

Prenatal fetal monitoring allows for the detection of abnormal physiologic conditions in the fetus. The different available methods can detect abnormalities in utero-placental perfusion, as well as physiologic changes during and after in-utero fetal surgery. Basic antepartum fetal monitoring in viable fetuses has advanced over the years and now involves not only the nonstress test but more advanced methods which also take into account the ultrasound findings. Comprehension of the different fetal heart rate tracings allow for rapid intervention where necessary. Unfortunately, while many modes of surveillance exist, no single method can accurately identify a fetus that will progress to being stillbirth.