Hospital Surveys by the Centers for Medicare and Medicaid Services: An Analysis of More Than 34,000 Deficiencies.

Objectives: The aims of the study were to analyze hospital deficiencies reported by the Centers for Medicare and Medicaid Services (CMS) for a 10-year period (2007-2017) and thereby determine the specific conditions of participation (CoP) cited in each deficiency.

Methods: Deficiency data from the CMS Web site was downloaded and analyzed. A determination was made regarding the CoP assigned to each deficiency.

How many operating rooms are needed to manage non-elective surgical cases? A Monte Carlo simulation study.

Background: Patients often wait to have urgent or emergency surgery. The number of operating rooms (ORs) needed to minimize waiting time while optimizing resources can be determined using queuing theory and computer simulation. We developed a computer program using Monte Carlo simulation to determine the number of ORs needed to minimize patient wait times while optimizing resources.

Optimizing the OR: a bottom-up approach.

Efficiency in the operating room (OR) has important implications on finances, access, and patient and staff satisfaction. UC Davis Medical Center (UCDMC) launched an initiative to increase OR efficiency by using multidisciplinary staff-based teams. The initiative freed up 5,500 annual hours-about 1 hr per operating room per day-in the OR by improving the percentage of first case on-time starts, reducing OR turnover times, improving scheduling predictability and reducing the number of controllable cancellations.

Effect of high-frequency alternating current on spinal afferent nociceptive transmission.

Objective: The study was performed to test the hypothesis that high-frequency alternating current (HFAC) ranging from 2 to 100 kHz delivered to the spinal dorsal roots reduces activity of spinal wide dynamic range (WDR) dorsal horn neurons (DHNs) during noxious peripheral stimulation.

Materials And Methods: This hypothesis was tested in both small and large animal in vivo preparations. Single-unit extracellular spinal DHN recordings were performed in seven adult rats and four adult goats while testing various parameters of HFAC delivered to the nerve roots or dorsal root entry zone using various electrode types.

Propofol and etomidate depress cortical, thalamic, and reticular formation neurons during anesthetic-induced unconsciousness.

Background: The sites where anesthetics produce unconsciousness are not well understood. Likely sites include the cerebral cortex, thalamus, and reticular formation. We examined the effects of propofol and etomidate on neuronal function in the cortex, thalamus, and reticular formation in intact animals.

Perioperative hypotension and myocardial ischemia: diagnostic and therapeutic approaches.

Although perioperative hypotension is a common problem, its true incidence is largely unknown. There is evidence that postoperative outcome, including the incidence of myocardial adverse events, may be linked to the prolonged episodes of perioperative hypotension. Despite this, there are very few comprehensive resources available in the literature regarding diagnosis and management of these not so uncommon clinical occurrences, especially during non-cardiac surgery.

Perioperative pharmacology in elderly patients.

Purpose Of Review: Populations across the world are getting older and requiring more surgery. Elderly patients present unique challenges to the anesthesiologist and anesthesia-care team. This review addresses some concerns when caring for an elderly patient.

Nitrous oxide-induced analgesia does not influence nitrous oxide's immobilizing requirements.

Background: Nitrous oxide (N(2)O) acts on supraspinal noradrenergic neurons to produce analgesia, but it is unclear if analgesia contributes to N(2)O's immobilizing effects. We tested the hypothesis that N(2)O minimum alveolar anesthetic concentration (MAC) is unchanged after selective ablation of supraspinal noradrenergic neurons, or in naïve animals at N(2)O exposure timepoints when analgesia is absent.

Methods: We determined tailflick latency (TFL) and hindpaw withdrawal latency (HPL) under 70% N(2)O, N(2)O MAC, and isoflurane MAC before and after intracerebroventricular injections of anti-dopamine-beta hydroxylase conjugated to saporin (SAP-DBH; n = 7), or a control antibody conjugated to saporin (n = 5).

Modeling the effects of midazolam on cortical and thalamic neurons.

Controversy exists regarding the site where anesthetics act in the brain to produce sedation and unconsciousness. Actions in the cerebral cortex and thalamus are likely, although the relative importance of each site is unclear. We used in computo modeling to investigate the sensitivity of cortical and thalamic neurons to midazolam (MDZ) at concentrations that produce unconsciousness.

Rat dorsal horn nociceptive-specific neurons are more sensitive than wide dynamic range neurons to depression by immobilizing doses of volatile anesthetics: an effect partially reversed by the opioid receptor antagonist naloxone.

Background: The mechanism and site of action within the spinal cord by which volatile anesthetics produce immobility are not well understood. Little work has been done directly comparing anesthetic effects on neurons with specific functional characteristics that mediate transfer of nociceptive information within the spinal cord.

Methods: Adult male rats were anesthetized and prepared for extracellular single-unit recordings from the lumbar dorsal horn.

Propofol produces immobility via action in the ventral horn of the spinal cord by a GABAergic mechanism.

Background: We investigated the actions of propofol and isoflurane on nociceptive responses of neurons in the spinal cord.

Methods: We determined nociceptive responses of lumbar neurons in the dorsal horn (<1200 microm) and ventral horn (>1200 microm) of decerebrate rats before and during propofol (1 effective dose, ED(50)) or isoflurane (1 minimum alveolar concentration) anesthesia. During recording of ventral horn neurons, we administered picrotoxin by infusion to determine whether isoflurane and propofol differed in their effects at the gamma aminobutyric acid (GABA) Type A receptors.

Perioperative drug therapy in elderly patients.

Advances in modern medicine and public health have resulted in increased longevity, which in turn has resulted in more elderly patients (arbitrarily defined as aged 65 yr or older) coming to the operating room for a variety of surgical procedures. Even in the absence of comorbidities, these patients, as compared with their younger cohorts, respond differently to various perioperative physiologic trespasses and pharmacologic interventions. In this clinical commentary, we focus on the altered pharmacologic responses elderly patients have during the perioperative period.

Proprioceptive function is more sensitive than motor function to desflurane anesthesia.

Background: Evaluating the effects of sub-immobilizing anesthetic doses on movement will identify target neural circuits for investigation as sites of action for anesthetic-induced immobility.

Methods: Eleven pithed Northern Leopard frogs received 0, 0.4, 0.

Modeling the GABAergic action of etomidate on the thalamocortical system.

Background: We have used a computational model of the thalamocortical system to investigate the effects of a GABAergic anesthetic (etomidate) on cerebral cortical and thalamic neuronal function. We examined the effects of phasic and tonic inhibition, as well as the relative importance of anesthetic action in the thalamus and cortex.

Methods: The amount of phasic GABAergic inhibition was adjusted in the model to simulate etomidate concentrations of between 0.

Increases in spinal cerebrospinal fluid potassium concentration do not increase isoflurane minimum alveolar concentration in rats.

Background: Previous studies demonstrated that MAC for isoflurane directly correlates with the concentration of Na(+) in cerebrospinal fluid surrounding the spinal cord, the primary site for mediation of the immobility produced by inhaled anesthetics. If this correlation resulted from increased irritability of the cord, then infusion of increased concentrations of potassium (K(+)) might be predicted to act similarly. However, an absence of effect of K(+) might be interpreted to indicate that K(+) channels do not mediate the immobility produced by inhaled anesthetics whereas Na(+) channels remain as potential mediators.

The effects of aromatic anesthetics on dorsal horn neuronal responses to noxious stimulation.

Background: Gamma-aminobutyric acid type A receptor potentiation and/or N-methyl-d-aspartate (NMDA) receptor inhibition might explain the anesthetic properties of fluorinated aromatic compounds. We hypothesized that depression of dorsal horn neuronal responses to noxious stimulation would correlate with the magnitude of effect of benzene (BNZ), o-difluorobenzene, and hexafluorobenzene (HFB) on NMDA receptors.

Methods: Rats were anesthetized with desflurane.

Immobilizing doses of halothane, isoflurane or propofol, do not preferentially depress noxious heat-evoked responses of rat lumbar dorsal horn neurons with ascending projections.

Background: The spinal cord is an important site where volatile anesthetics decrease sensation and produce immobility. Beyond this knowledge, our understanding of a site of anesthetic action is limited. Previous evidence suggests that dorsal horn neurons with ascending projections may be more susceptible to depression by general anesthetics than local spinal interneurons.

Temporal and spatial determinants of sacral dorsal horn neuronal windup in relation to isoflurane-induced immobility.

Background: Windup is a progressive increase in response of dorsal horn neurons to repetitive C-fiber stimulation that may underlie temporal summation of pain. We investigated the frequency- and intensity-dependency of windup, and the effects of isoflurane and N-methyl-d-aspartate (NMDA) receptor blockade, to determine if they parallel the influence of temporal and spatial summation of noxious stimuli on anesthetic requirements.

Methods: We recorded responses of rat sacral dorsal horn neurons to 20-s trains of electrical tail stimulation at different frequencies (0.

Glutamate receptor blockade in the rostral ventromedial medulla reduces the force of multisegmental motor responses to supramaximal noxious stimuli.

The rostral ventromedial medulla (RVM) has been established as part of a descending pain-modulatory pathway. While the RVM has been shown to modulate homosegmental nociceptive reflexes such as tail flick or hindpaw withdrawal, it is not known what role the RVM plays in modulating the magnitude of multisegmental, organized motor responses elicited by noxious stimuli. Using local blockade of glutamate receptors with the non-specific glutamate receptor antagonist kynurenate (known to selectively block nociceptive facilitatory ON-cells), we tested the hypothesis that the RVM facilitates the magnitude of multi-limb movements elicited by intense noxious stimuli.

Neurons in the ventral spinal cord are more depressed by isoflurane, halothane, and propofol than are neurons in the dorsal spinal cord.

Background: Volatile anesthetics act primarily in the spinal cord to produce immobility but their exact site of action is unclear. Between 0.8 and 1.

Isoflurane depression of spinal nociceptive processing and minimum alveolar anesthetic concentration are not attenuated in mice expressing isoflurane resistant gamma-aminobutyric acid type-A receptors.

Anesthetics produce immobility and depress spinal nociceptive processing, but the exact sites and mechanisms of anesthetic action are unknown. The gamma-aminobutyric acid type-A (GABAA) receptor is thought to be important to anesthetic action. We studied knock-in mice that had mutations in the alpha1 subunit of the GABAA receptor that imparts resistance to isoflurane in in vitro systems.

The excitatory and inhibitory effects of nitrous oxide on spinal neuronal responses to noxious stimulation.

Background: Because of the logistical obstacles to measurement under hyperbaric conditions, the effect of nitrous oxide (N2O) alone on spinal neuronal responses has not been tested. We hypothesized that, like other inhaled anesthetics, N2O would depress spinal neuronal responses to noxious stimulation.

Methods: The lumbar spinal cord was exposed in rats anesthetized with isoflurane.