Epidemiology and impact of methicillin-sensitive Staphylococcus aureus with β-lactam antibiotic inoculum effects in adults with cystic fibrosis

Staphylococcus aureus is the most prevalent cystic fibrosis (CF) pathogen. Several phenotypes are associated with worsened CF clinical outcomes including methicillin-resistance and small-colony-variants. The inoculum effect (IE) is characterized by reduced β-lactam susceptibility when assessed at high inoculum. The IE associates with worse outcomes in bacteremia and other high-density infections, and may therefore be relevant to CF. The prevalence of IE amongst a CF cohort (age ≥18 years), followed from 2013 to 2016, was investigated. Yearly methicillin-sensitive S. aureus (MSSA) isolates were screened at standard (5 × 105 CFU/mL) and high (5 × 107 CFU/mL) inoculum against narrow-spectrum anti-Staphylococcal β-lactams and those with anti-pseudomonal activity common to CF. A ≥ 4-fold increase in minimum inhibitory concentration between standard and high inoculum defined IE. Isolates underwent blaZ sequencing and genotyping and were compared against published genomes. Fifty-six percent (99/177) of individuals had MSSA infection. MSSA was observed at ≥105 CFU/mL in 44.8% of entry sputum samples. The prevalence of the IE was 25.0%-cefazolin; 13.5%-cloxacillin; 0%-meropenem; 1.0%-cefepime; 5.2%-ceftazidime; and 34.4%-piperacillin-tazobactam amongst baseline MSSA isolates assessed. blaZ A associated with cefazolin IE (P = 0.0011), whereas blaZ C associated with piperacillin-tazobactam IE (P < 0.0001). Baseline demographics did not reveal specific risk factors for IE-associated infections, nor were long-term outcomes different. Herein, we observed the IE in CF-derived MSSA disproportionally for cefazolin and piperacillin-tazobactam and this phenotype strongly associated with underlying blaZ genotype. The confirmation of CF being a high density infection, and the identification of high prevalence of MSSA with IE in CF supports the need for prospective pulmonary exacerbation treatment studies to understand the impact of this phenotype.

Casemix, management, and mortality of patients rreseceiving emergency neurosurgery for traumatic brain injury in the Global Neurotrauma Outcomes Study: a prospective observational cohort study

BACKGROUND

Traumatic brain injury (TBI) is increasingly recognised as being responsible for a substantial proportion of the global burden of disease. Neurosurgical interventions are an important aspect of care for patients with TBI, but there is little epidemiological data available on this patient population. We aimed to characterise differences in casemix, management, and mortality of patients receiving emergency neurosurgery for TBI across different levels of human development.

METHODS

We did a prospective observational cohort study of consecutive patients with TBI undergoing emergency neurosurgery, in a convenience sample of hospitals identified by open invitation, through international and regional scientific societies and meetings, individual contacts, and social media. Patients receiving emergency neurosurgery for TBI in each hospital's 30-day study period were all eligible for inclusion, with the exception of patients undergoing insertion of an intracranial pressure monitor only, ventriculostomy placement only, or a procedure for drainage of a chronic subdural haematoma. The primary outcome was mortality at 14 days postoperatively (or last point of observation if the patient was discharged before this time point). Countries were stratified according to their Human Development Index (HDI)-a composite of life expectancy, education, and income measures-into very high HDI, high HDI, medium HDI, and low HDI tiers. Mixed effects logistic regression was used to examine the effect of HDI on mortality while accounting for and quantifying between-hospital and between-country variation.

FINDINGS

Our study included 1635 records from 159 hospitals in 57 countries, collected between Nov 1, 2018, and Jan 31, 2020. 328 (20%) records were from countries in the very high HDI tier, 539 (33%) from countries in the high HDI tier, 614 (38%) from countries in the medium HDI tier, and 154 (9%) from countries in the low HDI tier. The median age was 35 years (IQR 24-51), with the oldest patients in the very high HDI tier (median 54 years, IQR 34-69) and the youngest in the low HDI tier (median 28 years, IQR 20-38). The most common procedures were elevation of a depressed skull fracture in the low HDI tier (69 [45%]), evacuation of a supratentorial extradural haematoma in the medium HDI tier (189 [31%]) and high HDI tier (173 [32%]), and evacuation of a supratentorial acute subdural haematoma in the very high HDI tier (155 [47%]). Median time from injury to surgery was 13 h (IQR 6-32). Overall mortality was 18% (299 of 1635). After adjustment for casemix, the odds of mortality were greater in the medium HDI tier (odds ratio [OR] 2·84, 95% CI 1·55-5·2) and high HDI tier (2·26, 1·23-4·15), but not the low HDI tier (1·66, 0·61-4·46), relative to the very high HDI tier. There was significant between-hospital variation in mortality (median OR 2·04, 95% CI 1·17-2·49).

INTERPRETATION

Patients receiving emergency neurosurgery for TBI differed considerably in their admission characteristics and management across human development settings. Level of human development was associated with mortality. Substantial opportunities to improve care globally were identified, including reducing delays to surgery. Between-hospital variation in mortality suggests changes at an institutional level could influence outcome and comparative effectiveness research could identify best practices.

FUNDING

National Institute for Health Research Global Health Research Group.

Liver dysfunction and hypoglycaemia as presentations of hypopituitarism in a child

Not required for Clinical Vignette.

Appendicitis in pregnancy: new information that contradicts long-held clinical beliefs

OBJECTIVE

Our purpose was to elicit a better understanding of the presentation of acute appendicitis in pregnancy and to clarify diagnostic dilemmas reported in the literature.

STUDY DESIGN

We retrospectively reviewed 66,993 consecutive deliveries from 1986 to 1995 by a computer program. Selected records were reviewed for gestational age; signs and symptoms at presentation; complications including preterm contractions, preterm labor, and appendiceal rupture; and histologic diagnosis of appendicitis.

RESULTS

Of 66, 993 deliveries, 67 (0.1%) were complicated by a preoperative diagnosis of probable appendicitis. Acute appendicitis was confirmed histologically in 45 (67%) of the 67 cases, for an incidence of 1 in 1493 pregnancies in this population. Distribution of suspected appendicitis in pregnancy was as follows: first trimester, 17 cases (25%); second trimester, 27 (40%); and third trimester, 23 (34%). Right-lower-quadrant pain was the most common presenting symptom regardless of gestational age (first trimester, 12 [86%] of 14 cases; second trimester, 15 [83%] of 18 cases; and third trimester, 10 [78%] of 13 cases). The mean maximal temperature for proven appendicitis was 37.6 degrees C (35.5 degrees C-39.4 degrees C), in comparison with 37.8 degrees C (36.7 degrees C-38.9 degrees C; not significant) for those with normal histologic findings. The mean leukocyte count in patients with proven appendicitis was 16.4 x 10(9)/L (8.2-27.0 x 10(9)/L), in comparison with 14.0 x 10(9)/L (5. 9-25.0 x 10(9)/L) for patients with normal histologic findings. At the time of surgery, perforation had occurred in 8 cases. Of 23 patients at > or =24 weeks' gestational age, 19 (83%) had contractions and an additional 3 patients (13%) had preterm labor with documented cervical change. One patient was delivered in the immediate postoperative period because of abruptio placentae.

CONCLUSION

Pain in the right lower quadrant of the abdomen is the most common presenting symptom of appendicitis in pregnancy regardless of gestational age. Fever and leukocytosis are not clear indicators of appendicitis in pregnancy and preterm labor is a problem after appendectomy, but preterm delivery is rare.

[Combined lateral gaze palsy with unilateral internuclear ophthalmoplegia in high mesencephalic-pontine hemorrhage. Report of a case]

The authors report a case of right midbrain and high pons haemorrhage with complete external ophthalmoplegia, except bilateral convergence, voluntary and automatic-reflex abduction of the left eye and adduction of this eye with vestibulo-ocular reflex ("one-and-a-half syndrome"). There is voluntary-automatic dissociation of the eyelids motricity and the vertical gaze. Still, there is sensitive-motor hemiplegia at left and asterixis.