Microbiological findings and adequacy of antibiotic treatment in the critically ill patient with drowning-associated pneumonia

Microbiological features of drowning-associated pneumonia: a systematic review and meta-analysis

BACKGROUND

Drowning-associated pneumonia (DAP) is frequent in drowned patients, and possibly increases mortality. A better understanding of the microorganisms causing DAP could improve the adequacy of empirical antimicrobial therapy. We aimed to describe the pooled prevalence of DAP, the microorganisms involved, and the impact of DAP on drowned patients.

METHODS

Systematic review and meta-analysis of studies published between 01/2000 and 07/2023 reporting on DAP occurrence and microorganisms involved.

RESULTS

Of 309 unique articles screened, 6 were included, involving 688 patients. All were retrospective cohort studies, with a number of patients ranging from 37 to 270. Studies were conducted in Europe (France N = 3 and Netherland N = 1), United States of America (N = 1) and French West Indies (N = 1). Mortality ranged between 18 to 81%. The pooled prevalence of DAP was 39% (95%CI 29-48), similarly following freshwater (pooled prevalence 44%, 95%CI 36-52) or seawater drowning (pooled prevalence 42%, 95%CI 32-53). DAP did not significantly impact mortality (pooled odds ratio 1.43, 95%CI 0.56-3.67) but this estimation was based on two studies only. Respiratory samplings isolated 171 microorganisms, mostly Gram negative (98/171, 57%) and mainly Aeromonas sp. (20/171, 12%). Gram positive microorganisms represented 38/171 (22%) isolates, mainly Staphylococcus aureus (21/171, 12%). Water salinity levels had a limited impact on the distribution of microorganisms, except for Aeromonas sp. who were exclusively found following freshwater drowning (19/106, 18%) and never following seawater drowning (0%) (p = 0.001). No studies reported multidrug-resistant organisms but nearly 30% of the isolated microorganisms were resistant to amoxicillin-clavulanate, the drug that was the most commonly prescribed empirically for DAP.

CONCLUSIONS

DAP are commonly caused by Gram-negative bacteria, especially Aeromonas sp. which is exclusively isolated following freshwater drowning. Empirical antimicrobial therapy should consider covering them, noting than amoxicillin-clavulanate may be inadequate in about one-third of the cases. The impact of DAP on patients' outcome is still unclear.

Wide-spectrum antibiotic prophylaxis guarantees optimal outcomes in drowned donor kidney transplantation

BACKGROUND

Drowned victims possibly obtain various pathogens from drowning sites. Using drowned renal donors to expand the donor pool still lacks consensus due to the potential risk of disease transmission.

RESEARCH DESIGN AND METHODS

This retrospective study enrolled 38 drowned donor renal recipients in a large clinical center from August 2012 to February 2021. A 1:2 matched cohort was generated with donor demographics, including age, gender, BMI, and ICU durations. Donor microbiological results, recipient perioperative infections, and early post-transplant and first-year clinical outcomes were analyzed.

RESULTS

Compared to the control group, drowned donors had significantly increased positive fungal cultures (36.84% vs.13.15%, p = 0.039). Recipients in the drowned group had significantly higher rates of gram-negative bacteria (GNB) and multidrug-resistant GNB infections (23.68% vs.5.26%, 18.42% vs. 3.95%, both p < 0.05). Other colonization and infections were also numerically more frequent in the drowned group. Drowned donor recipients receiving inadequate antibiotic prophylaxis had more perioperative bloodstream infections, higher DGF incidences, and more first-year respiratory tract infections and recipient loss than those receiving adequate prophylaxis (all p < 0.05). Clinical outcomes were similar between the adequate group and the control group.

CONCLUSIONS

Drowned donors could be suitable options under wide-spectrum and adequate antimicrobial prophylaxis.

Clinical and microbiological features of drowning-associated pneumonia: a retrospective multicentre cohort study

OBJECTIVE

Pneumonia is the most frequent infectious complication in patients who have experienced drowning that requires intensive care unit (ICU) admission. We aimed to describe clinical, microbiological, and therapeutic data as well as predictors and impacts of such pneumonia on patients' outcomes.

METHODS

We conducted a retrospective, multicentre study (2013-2020) of 270 consecutive patients admitted for drowning to 14 ICUs in Western France. Their baseline characteristics and outcomes were compared according to the occurrence of drowning-associated pneumonia (DAP), defined as pneumonia diagnosed within 48 hours of ICU admission. A Cox regression model was used to compare survival on day 28, and logistic regression was used to identify risk factors for DAP. Microbiological characteristics and empirical antibacterial treatment were also analysed.

RESULTS

Among the 270 patients admitted to the ICU for drowning, 101 (37.4%) and 33 (12.2%) experienced pneumonia and microbiologically proven DAP, respectively. The occurrence of pneumonia was associated with higher severity scores at ICU admission (median Simplified Acute Physiology Score II, 34 [interquartile range {IQR}, 25-55] vs. 45 [IQR, 28-67]; p 0.006) and longer ICU length of stay (2 days [IQR, 1-3] vs. 4 days [IQR, 2-7]; p < 0.001). The 28-day mortality rate was higher among these patients (29/101 [28.7%] vs. 26/169 [15.4%]; p 0.013). Microbiologically proven DAP remained associated with higher 28-day mortality after adjustments for cardiac arrest and water salinity (adjusted hazard ratio, 1.86 [95% CI, 1.06-3.28]; p 0.03). A microbiological analysis of respiratory samples showed a high proportion of gram-negative bacilli (23/56; 41.1%), with a high prevalence of amoxicillin-clavulanate resistance (12/33; 36.4%).

CONCLUSIONS

Pneumonia is a common complication in patients admitted in the ICU for drowning and is associated with increased mortality.

[Clinical and microbiological characteristics of children with drowning-associated aspiration pneumonia]

OBJECTIVES

To study the clinical and microbiological characteristics of children with drowning-associated aspiration pneumonia, so as to provide a reference for empirical selection of antibacterial agents.

METHODS

A retrospective analysis was performed on the medical data of 185 children with drowning-associated aspiration pneumonia who were admitted to Children's Hospital of Chongqing Medical University from January 2010 to October 2020. According to the drowning environment, these children were divided into four groups: fecal group (n=44), freshwater group (n=69), swimming pool group (n=41), and contaminant water group (n=31). The clinical characteristics and pathogen detection results were reviewed and compared among the four groups.

RESULTS

The 185 children had an age of 4 months to 17 years (median 34 months). Sputum cultures were performed on 157 children, and 103 were tested positive (65.6%), with 87 strains of Gram-negative bacteria (68.5%), 37 strains of Gram-positive bacteria (29.1%), and 3 strains of fungi (2.4%). Gram-negative bacteria were the main pathogen in the fecal group and the contaminant water group, accounting for 88.2% (30/34) and 78.3% (18/23), respectively. The freshwater group had a significantly higher detection rate of Gram-positive bacteria than the fecal group (P<0.008), and the swimming pool group had an equal detection rate of Gram-negative bacteria and Gram-positive bacteria.

CONCLUSIONS

For pulmonary bacterial infection in children with drowning in feces or contaminant water, antibiotics against Gram-negative bacteria may be applied empirically, while for children with drowning in a swimming pool or freshwater, broad-spectrum antibiotics may be used as initial treatment, and subsequently the application of antibiotics may be adjusted according to the results of the drug sensitivity test.

Evaluation of Antimicrobial Utilization in the Pediatric Drowning Population

BACKGROUND

Management of pediatric drowning often includes evaluation and treatment of infectious disease. There are few data describing the infections associated with pediatric drowning.

METHODS

A descriptive retrospective study was designed, and patients aged < 19 years admitted for > 24 hours to our institution after a drowning were included from January 2011 through June 30, 2017. Data collection included patient demographics, submersion injury details, resuscitation details, patient admission details, chest radiograph on admission, use of intubation and mechanical ventilation, hospital length of stay, culture data, antimicrobial use, and mortality. Descriptive statistical methods (mean and standard deviation, median and range, percentage) were used to characterize the patient population, and Fisher exact test was used to evaluate the association between antimicrobial use in the first 72 hours of admission and mortality.

RESULTS

A total of 114 patients met study criteria (male, 59.7%; median age, 3.7 years [range, 0.15-17.79 years]). Median hospital length of stay was 2 days (range, 1-60 days). Intensive care unit admission occurred in 80.7%, intubation occurred in 46.5%, and mortality was 18.4%. The most common submersion location was a pool (76.3% [n = 87]) with water primarily characterized as freshwater (82.5% [n = 94]). Reported submersion time for the majority of patients was < 5 minutes (54.4%) with cardiopulmonary resuscitation in 78.1%. In the first 72 hours after admission, culture were obtained in 40 patients (35.1%), and 27.5% of these cultures were positive. The primary organisms identified were consistent oropharyngeal flora. Antimicrobials were initiated in 50% of the patient population with clindamycin as most common. There was not a significant association between antimicrobial use in the first 72 hours after admission and mortality (17.2% vs 19.6%, P = .81).

CONCLUSIONS

Infectious disease associated with pediatric drowning in pools is uncommon. Empiric use of antimicrobials does not appear to affect outcomes.

[Near-drowning associated Aeromonas pneumonia]

INTRODUCTION

Aeromonas pneumonia associated with near-drowning, though uncommon, is serious and a major morbidity factor for patients.

CLINICAL CASE

A healthy 30-year-old man nearly drowned in a pound. He was admitted to the medical intensive care unit and required intubation and mechanical ventilation. He was given antibiotic therapy in the form of amoxicillin/clavulanic acid. After a brief stable period post immersion, he rapidly developed fever and respiratory failure. The thoracic scan revealed bilateral alveolar infiltrates and led to a fibreoptic bronchoscopy. Aeromonas veroniiandPseudomonas aeruginosa were found on culture of the bronchial aspirate. A change of antibiotic therapy appropriate to these bacteria led to clinical improvement and allowed complete withdrawal of ventilation.

CONCLUSION

Rapid respiratory deterioration following near-drowning should raise the suspicion of pulmonary infection with the bacteria usually found in the respiratory tract during ventilation but without overlooking the possibility of unusual organisms, particularly Aeromonas.It is usuallysensitive to third generation cephalosporins and fluoroquinolones. Ideally, Aeromonas should be sought in pulmonary aspirates and samples of the water where immersion occurred.

Seawater drowning-associated pneumonia: a 10-year descriptive cohort in intensive care unit

BACKGROUND

Pneumonia is one of the major complications of drowning, but the optimal empirical antibiotic treatment is not clearly defined. Multidrug-resistant (MDR) bacteria and fungi have been identified in a recent series of freshwater drowning-associated pneumonia. However, microbial data in seawater drowning are scarce. The objective of the study is to describe the microorganisms isolated in early respiratory specimens obtained from seawater drowning-associated pneumonia and to provide their antibiotic susceptibility pattern.

METHODS

All patients admitted for seawater drowning between 2003 and 2013 to two intensive care units, from the region in France with the highest drowning rate, were retrospectively included. Demographics, antimicrobial therapy and microbiological data from respiratory samples collected within the first 48 h after admittance were analyzed.

RESULTS

Seventy-four drowned patients were included, of which 36 (49%) were diagnosed by the clinician as having early pneumonia. Concerning the overall population, the median simplified acute physiology score (version 2) was 45 (30-65), and the mortality was 26%. Twenty-four respiratory samples from different patients were obtained within the first 48 h. Sixteen were positive. The main microorganisms found were Enterobacteriaceae (Enterobacter spp., Klebsiella spp. and Escherichia coli) and Gram-positive aerobic cocci (Streptococcus pneumonia and Staphylococcus aureus) with a low rate of antimicrobial resistance. No MDR bacteria or fungi were identified. However, among the positive respiratory samples collected, 5/16 (31%) grew bacteria with natural resistance to amoxicillin-clavulanate, the first-line antibiotic commonly used in our cohort. Resistance was only found among Gram-negative bacteria and from respiratory samples of patients with a higher drowning grade at admission (p = 0.01).

CONCLUSIONS

This 10-year descriptive study, the largest cohort to date, provides early respiratory samples from seawater drowning patients. The microorganisms retrieved were either mostly part of the human oro-pharyngeal flora or Enterobacteriaceae and displayed low rates of antimicrobial resistance. Respiratory samples should nonetheless be collected at admittance to the ICU to avoid inappropriate treatment. Empiric use of cephalosporin could be restricted to severe patients or if Gram-negative bacilli are found after direct examination.