From measurements of airway and esophageal pressures and flow, we calculated the elastance and resistance of the total respiratory system (Ers and Rrs), chest wall (Ecw and Rcw), and lungs (EL and RL) in 11 anesthetized-paralyzed patients immediately before cardiac surgery with cardiopulmonary bypass and immediately after chest closure at the end of surgery. Measurements were made during mechanical ventilation in the frequency and tidal volume ranges of normal breathing. Before surgery, frequency and tidal volume dependences of the elastances and resistances were similar to those previously measured in awake seated subjects (Am. Rev. Respir. Dis. 145: 110-113, 1992). After surgery, Ers and Rrs increased as a result of increases in EL and RL (P < 0.05), whereas Ecw and Rcw did not change (P > 0.05). EL and RL exhibited nonlinearities (i.e., decreases with increasing tidal volume) that were not seen before surgery, and RL showed a greater dependence on frequency than before surgery. The changes in RL or EL after surgery were not correlated with the duration of surgery or cardiopulmonary bypass time (P > 0.05). We conclude that 1) frequency and tidal volume dependences of respiratory system properties are not affected by anesthesia, paralysis, and the supine posture, 2) open-chest surgery with cardiopulmonary bypass does not affect the mechanical properties of the chest, and 3) cardiac surgery involving cardiopulmonary bypass causes changes in the mechanical behavior of the lung that are generally consistent with those caused by pulmonary edema induced by oleic acid (J. Appl. Physiol. 73: 1040-1046, 1992) and decreases in lung volume.

To our knowledge, this is the largest study of the benefit of percutaneous tracheostomy in a critically injured trauma population. The risk of SSI is significantly lower after percutaneous than open tracheostomy.

INTRODUCTIONThis monograph is concerned primarily with the pharmacology of analgesic agents with regard to their modification of pain perception a t various levels in the central nervous system. Pain is also of interest to adrenal physiologists such as ourselves, since it constitutes a most potent activator of the pituitary adrenal system. Drugs that act upon the central nervous system to suppress pain would be expected also to affect those adrenal cortical responses that are physiological concomitants of painful stimuli, such as the rise in cortisol secretion. Thus it seemed of interest to invektigate the influence of various psychotropic agents upon adrenal cortical activation.Certain areas of the brain, notably the hypothalamus,'-a critically influence the regulation and release of corticotropin by the hypophysis. Several wellknown pharmacological suppressants of cerebral function such as m~r p h i n e ,~ barbiturates,6 and diphenylhydantoine have been reported to impair pituitary ACTH secretion, probably through inhibition of hypothalamic centers? Animal studies indicate that chl~rpromazine~ and reserpines also suppress corticotropin release through hypothalamic inhibition. In man, chlorpromazine has been found to prevent the increase in plasma 17-hydroxycorticoids induced by insulin hypoglycemia? However, the noxious nature of the stimuli necessary to evoke corticotropin release has somewhat limited investigations regarding the influence of analgesic and ataractic drugs upon pituitary-adrenal-cortical function in human subjects.A quantitative as well as more convenient approach to this problem was suggested by recent work on a relatively nontoxic analogue of amphenone, SU-4885.lo This agent acts within the adrenal cortex to inhibit enzymatic hydroxylation of carbon 11 in the cortisol molecule, thereby reducing synthesis of biologically active cortiso1.l1 ~2 The decline in circulating cortisol that follows provides a nontraumatic stimulus to corticotropin secretion by the pituitary (FIGURE 1). The increase in urinary 17-ketogenic steroids (17-KGS) that the adrenal is stimulated to secrete under these conditions, particularly 11desoxycortisol and related compounds, can then be measured. Thus the rise in 17-KGS excretion above basal levels noted after administration of SU-4885 reflects secretion of endogenous ACTH.In the preliminary studies presented here, a standardized test procedure with SU-4885 has been employed to evaluate the effect of various drugs known to affect the central nervous system upon pituitary and adrenal function.

At the inaugural Frontiers in Hydrology Meeting in San Juan, Puerto Rico in the summer of 2022, the Hydrology Section organized a poster session and invited our 2020 and 2021 Classes of AGU Fellows, with the initial goal of both celebrating their careers as well as to provide an opportunity for an informal exchange and connection between the section's early career members and our more senior and established scientists and engineers. Due to the challenges of time zones, virtual poster presentations and other logistics, the formal poster session was adjourned but continued as a hybrid “meet‐up” with six of our Section's Fellows (Suzanne Anderson, Paul Brooks, Aaron Packman, Remko Uijlenhoet, Andrew Western, and Xubin Zeng) from around the world. As you will see, what started as an informal chat quickly took deep dives into pressing issues in our section and science in general, including thoughts on how our community values (or in some cases doesn't value) multi‐ and interdisciplinary accomplishments, critiques of our system of rewards and awards including how we assess publication impacts and finally, a frank and honest discussion of our current efforts to diversify our community and where/why are we still failing. We hope that by sharing this open and impromptu dialogue that these discussions can expand to our entire community, and to encourage future Fellows exchanges such as this to reach our entire community of scientists and engineers.