Moving towards a standardized definition of antimicrobial resistance: a comparison of the antimicrobial susceptibility profile of difficult-to-treat resistance (DTR) versus multidrug-resistant (MDR) Pseudomonas aeruginosa clinical isolates (CANWARD, 2016-2021)

Pseudomonas aeruginosa clinical isolates demonstrating difficult-to-treat resistance (DTR) and multidrug-resistant (MDR) phenotypes were evaluated by broth microdilution. Susceptibility was lower for all antimicrobials versus DTR relative to MDR isolates. Ceftazidime-avibactam, ceftolozane-tazobactam, and imipenem-relebactam susceptibility was 35.9%, 64.5%, and 47.0% for DTR isolates and 60.5%, 80.6%, and 71.5% for MDR isolates.

Antimicrobial susceptibility of clinical isolates of Neisseria gonorrhoeae to alternative antimicrobials with therapeutic potential

Background

The prevalence of MDR Neisseria gonorrhoeae is increasing globally and represents a public health emergency. Development and approval of new anti-gonococcal agents may take years. As a concurrent approach to developing new antimicrobials, the laboratory and clinical evaluation of currently licensed antimicrobials not widely used for the treatment of gonorrhoea may provide new options for the treatment of gonococcal infections.

Objectives

To determine the in vitro activity of nine alternative, currently licensed and late-development antimicrobials with the potential to treat gonococcal infections against 112 clinical isolates of N. gonorrhoeae resistant to one or multiple antimicrobials.

Methods

The MICs of conventional anti-gonococcal antimicrobials (penicillin, ceftriaxone, cefixime, azithromycin, ciprofloxacin, tetracycline and spectinomycin) and alternative antimicrobials (ertapenem, gentamicin, netilmicin, tigecycline, eravacycline, fosfomycin, linezolid, ceftazidime/avibactam and ceftaroline) were determined by agar dilution.

Results

Ertapenem and the novel cephalosporins demonstrated similar MIC values to the third-generation cephalosporins, but increased MICs were observed for isolates with increased cefixime and ceftriaxone MICs. Tigecycline and eravacycline had MIC values below expected serum concentrations for all isolates tested. The aminoglycosides gentamicin and netilmicin were generally more potent than spectinomycin, with netilmicin demonstrating the greatest potency. Fosfomycin MICs were elevated compared with other agents, but remained within the MIC range for susceptible organisms, while linezolid MICs were generally higher than those for organisms considered resistant.

Conclusions

Among potentially therapeutically useful alternative agents, the aminoglycosides, eravacycline, tigecycline and fosfomycin had good in vitro activity. The novel cephalosporins and ertapenem had comparable activity to cefixime and ceftriaxone.

In vitro activity of oritavancin against Gram-positive pathogens isolated in Canadian hospital laboratories from 2011 to 2013

Gram-positive pathogens isolated in 15 Canadian hospital laboratories between 2011 and 2013 were tested for susceptibility to oritavancin and comparative antimicrobial agents using the Clinical and Laboratory Standards Institute broth microdilution method. Oritavancin demonstrated in vitro activity equivalent to, or more potent than, vancomycin, daptomycin, linezolid, and tigecycline against the isolates of methicillin-susceptible Staphylococcus aureus (n=1460; oritavancin MIC90, 0.06 μg/mL; 99.7% oritavancin-susceptible), methicillin-resistant S. aureus (n=427; oritavancin MIC90, 0.06 μg/mL; 99.5% oritavancin-susceptible), Streptococcus pyogenes (n=132; oritavancin MIC90, 0.25 μg/mL; 99.2% oritavancin-susceptible), Streptococcus agalactiae (n=156; oritavancin MIC90, 0.12 μg/mL; 100% oritavancin-susceptible), and Enterococcus faecalis (n=304; oritavancin MIC90, 0.06 μg/mL; 98.7% oritavancin-susceptible) tested.

Ondansetron is a better prophylactic antiemetic than droperidol for tonsillectomy in children

Both intravenous ondansetron (OND) and droperidol (DROP) have been observed to reduce vomiting after tonsillectomy in children. This randomized, double-blind investigation compared the effect of OND and DROP on vomiting after outpatient tonsillectomy in 276 healthy children age 2-12 yr. All subjects received a standardized anaesthetic, which consisted of induction with either propofol or halothane/N2O, vecuronium 0.1 mg x kg(-1) on an as needed basis, maintenance with halothane/N2O, midazolam and codeine, and reversal of neuromuscular blockade with neostigmine and atropine on an as needed basis. Subjects were given either OND 150 micrograms x kg(-1) or DROP 50 micrograms x kg(-1)iv after induction of anaesthesia. Rescue antiemetics in the hospital were administered to patients who vomited X 2 and X 4, respectively. Postoperative pain was treated with morphine, codeine and/or acetaminophen. For 24 hr following surgery, emesis was recorded by nursing staff while subjects were in the hospital, and by parents following discharge from hospital. The two groups were similar with respect to demographic data, induction technique and anaesthesia time. The frequency of in-hospital emesis was 16% in the OND-patients and 30% in the DROP-group, P <0.05. The OND-subjects required fewer rescue antiemetics, 5% vs 13%, P <0.05. The overall incidence of emesis was 45% in the OND-group and 57% in the DROP-group, P <0.05. In conclusion, ondansetron was a superior prophylactic antiemetic for tonsillectomy in children when compared to droperidol.

Oral ondansetron decreases vomiting after tonsillectomy in children

Vomiting is a common, unpleasant aftermath of tonsillectomy in children. Intraoperative intravenous ondansetron (OND) reduces vomiting after this operation. Our double-blind, placebo-controlled, randomized investigation studied the effect of the oral form of OND on vomiting after outpatient tonsillectomy in children. We studied 233 healthy children age 2-14 yr undergoing elective tonsillectomy. Subjects were given placebo (PLAC) or OND 0.1 mg.kg-1 rounded off to the nearest 2 mg one hr before surgery. Anaesthesia was induced with either propofol or halothane/N2O. Vecuronium 0.1 mg.kg-1 was administered at the discretion of the anaesthetist. Anaesthesia was maintained with halothane/N2O, 50 micrograms.kg-1 midazolam iv and 1-1.5 mg.kg-1 codeine im. At the end of surgery, residual neuromuscular blockade was reversed with neostigmine and atropine. All episodes of in-hospital emesis were recorded by nursing staff. Rescue antiemetics in the hospital were 1 mg.kg-1 dimenhydrinate iv for vomiting x 2 and 50 micrograms.kg-1 droperidol iv for vomiting x 4. Parents kept a diary of emesis after discharge. Postoperative pain was treated with morphine, codeine and/or acetaminophen. The two groups were similar with respect to demographic data, induction technique and anaesthesia time. Oral OND (n = 109) reduced postoperative emesis from 54% to 39%, P < 0.05. This effect was most dramatic in-hospital, where 10% of the OND-patients and 30% of the PLAC-group vomited, P < 0.05. The OND-subjects required fewer rescue antiemetics, 7% vs 17%, P < 0.05. In conclusion, oral ondansetron decreased the incidence of vomiting after outpatient tonsillectomy in children.

The welfare problems of laying hens in battery cages

So far as feeding, health and protection from cannibalism are concerned, the welfare needs of laying hens can be well catered for in cages. In other respects, however, cages fail to provide for hens' welfare needs. Deprived of litter, caged hens are prevented from dust bathing and foraging. Without access to a nest site, nesting motivation is frustrated and without a perch, roosting is prevented. Restrictions on movement within a cage cause frustration and prevent normal bone maintenance, particularly in the legs and wings. Confinement in a battery cage is concluded to cause suffering to laying hens in several different ways.

Congenital laryngomalacia

There is at present, very little information on congenital laryngomalacia in the anaesthetic literature. The purpose of this article is to review this topic, which in 90% of patients represents a benign self-limiting condition, disappearing by the age of two to five years. However, if untreated, the remaining 10% of cases can prove fatal. This severe form presents as persistent sternal recession, feeding difficulties, and failure to thrive, progressing to apnoeic attacks, cor pulmonale and eventually death. The developmental and functional anatomy of the larynx will be included, with a discussion of the pathophysiology and history of the disorder. Its diagnosis and a résumé of the various treatment strategies, will be presented. The anaesthetic management is controversial as is the surgical technology. Our technique, for diagnosis or definitive repair, is based upon suspension laryngoscopy using topical local analgesia and spontaneous ventilation. Halothane is then administered by insufflation into the pharynx, using a #8 nasopharyngeal catheter, and suction is applied to the mouth. During the surgical repair, an endotracheal tube (ETT), may be inserted, at the discretion of the anaesthetist and surgeon. Finally, the role of the dioxide CO2 laser and its hazards will be introduced.

Onset of maximum neuromuscular block following succinylcholine or vecuronium in four age groups

BACKGROUND

Increasing age appears to be associated with a slower onset of neuromuscular blockade, but such an effect has not been studied with the same doses of the same drugs across pediatric and adult age groups.

METHODS

The authors measured the evoked compound action potential of the adductor pollicis muscle in response to 0.1-Hz stimulation of the ulnar nerve, during fentanyl-thiopental-oxygen anesthesia, in 160 patients aged 1-3 yr, 3-10 yr, 20-40 yr, or 60-80 yr. Subparalyzing doses of vecuronium (0.03 mg/kg) or succinylcholine (0.3 mg/kg), or paralyzing doses of vecuronium (0.1 mg/kg) or succinylcholine (1.0 mg/kg), were administered to ten patients in each age group.

RESULTS

Onset time, defined as the time from injection to maximum depression of response with a subparalyzing dose or the time from injection to ablation of visible response with a paralyzing dose, varied with age in all groups (P < 0.001). For 0.3 mg/kg succinylcholine, it increased from 49 +/- 6 s in 1-3-yr-old patients, to 104 +/- 9 s in 60-80-yr-old patients (P < 0.00001). For 0.03 mg/kg vecuronium, onset time was 3.6-5.9 times longer than for succinylcholine, increasing from 219 +/- 15 s in 3-10-yr-old patients to 473 +/- 30 s in 60-80-yr-old patients (P < 0.00001 by linear regression). For paralyzing doses, succinylcholine 1.0 mg/kg had an onset time of 58 +/- 7 s and 95 +/- 7 s, in 1-3-yr-old and 60-80-yr-old patients, respectively (P < 0.001). For 0.1 mg/kg vecuronium, onset time varied between 125 +/- 19 s in 1-3-yr-old patients to 295 +/- 31 s in 60-80-yr-old patients (P < 0.00001), and was 2.1-3.3 times longer than 1 mg/kg succinylcholine.

CONCLUSIONS

Increasing age is associated with slower onset for both succinylcholine and vecuronium. When equipotent, subparalyzing doses of succinylcholine and vecuronium are compared, onset time is 4.5 times as long with vecuronium.

Postoperative neuromuscular function in pediatric day-care patients

After anesthesia employing nondepolarizing muscle relaxants, 30%-40% of adult patients demonstrate residual paralysis with a train-of-four ratio less than 70%, but it is not known if the same is true for children. This study was designed to investigate neuromuscular transmission in 91 ASA physical status I or II day-care children (aged 0-10 yr) after halothane anesthesia in which pancuronium (n = 34), atracurium (n = 32), or vecuronium (n = 25) was administered. Peripheral nerve stimulation was used clinically to assess neuromuscular blockade during surgery. In the recovery room, the evoked response of the adductor pollicis muscle was measured by train-of-four stimulation of the ulnar nerve. This measurement was made (mean +/- SEM) at 18.0 +/- 1.5, 15.0 +/- 1.3, and 15.0 +/- 1.7 min after pharmacologic antagonism with 0.02 mg/kg atropine and 0.06 mg/kg neostigmine in the pancuronium, atracurium, and vecuronium groups, respectively. There were no differences in the ages of the patients in the three groups at 4.3 +/- 0.4, 4.0 +/- 0.4, and 5.0 +/- 0.5 yr, with 17 children less than 2 yr. Recovery from neuromuscular blockade in all three groups was almost complete. The train-of-four ratio (height of fourth twitch compared with the first) was similar in patients who had received pancuronium (96.7% +/- 0.9%), atracurium (95.5% +/- 0.9%), or vecuronium (96.3% +/- 1.3%). Therefore, postoperative muscle weakness or respiratory impairment is unlikely in pediatric day-care surgical patients more than 2 yr old when these anesthetic techniques are used.

Intensive housing: the last straw for pigs?

The concept of coping can be used to relate the environmental conditions provided for livestock to their responses--their productivity and their welfare. Pigs are "ecological generalists" and hence are "designed" to cope with a wide variety of environmental conditions. They, however, show clear limits to their adaptability both in terms of the space they require and the pen materials they can endure without injury. Even where they adapt to a wide range of conditions, there often is a particular environment that gives optimum performance. Examples of temperature requirements and feeding facilities are discussed. The process of coping is shown to impose a biological "cost" in some instances and, although a pig has adapted to a specific environment, questions still remain concerning whether keeping a pig in that environment is justifiable.