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Hospital-acquired bacterial infections in patients with cirrhosis undergoing selective intestinal decontamination
262
LETTERS TO THE EDITOR
HEPAT 01342
Hospital-acquired bacterial infections in patients with cirrhosis undergoing selective intestinal decontamination Cirrhotic patients show a higher incidence of hospitalacquired bacterial infections (17-35%) than the general hospital population (3-6%). Enteric aerobic gramnegative bacilli are the bacteria most frequently involved. Since bacterial infections in cirrhotic patients are re-
TABLE 1
lated to a poor prognosis and a low short-term survival rate, prophylaxis of infection is a logical approach and inhibition of enteric gram-negative bacilli by means of oral antibiotics has been proposed (1). Two controlled trials have demonstrated the useful-
Patients Numberof infections SBP CNNAa Bacterascitesb Bacteremia Respiratory Urinary Perinealabscess
ness of selective intestinal decontamination (SID) with oral norfloxacin in the prevention of bacterial infections in cirrhotic patients at high risk of infection (2,3). Interestingly, it seems that SID causes a change in the bacteria responsible for the infections in cirrhosis, since the bacteria most frequently isolated in treated patients from these two studies were gram-positive cocci instead of gram-negative bacilli. In the present study, hospital-acquired bacterial infections of 156 cirrhotic patients at high risk of infection undergoing SID with norfloxacin have been analyzed. Eighty-seven patients were hospitalized with ascites and ascitic fluid total protein < 1.5 g/dl (group I) and 69 patients were hospitalized because of gastrointestinal hemorrhage (group II). Patients from group I were treated with oral norfloxacin 400 mg/day during the entire hospitalization period and group II received 400 mg b.i.d, orally or through nasogastric tube during the first 7 days of hospitalization. Table 1 shows the 15 episodes of infection observed in 14 of the 156 patients, six with ascites (6.8%) and eight with gastrointestinal hemorrhage (11.5%). The incidence of infection was similar to that previously reported in patients belonging to the same groups at high risk submitted to SID and lower than in non-SID patients from other series (3,4). The bacteria responsible for the infections are listed in Table 2. Twelve infections were microbiologically proven (80%) and a total of 14 bacteria were isolated. Gram-positive cocci were present in 10 infections (66.6%), anaerobic bacteria in 2 (13.3%) and gramnegative bacilli in only one (6.6%). Therefore, the incidence of gram-positive cocci and gram-negative bacilli
Incidence (%) and source of infection in each group Group I (n = 87)
GroupII (n = 69)
Total (n = 156)
6 (6.8%) 6 2 1 0 3 0 0 0
8 (11.5%) 9 3 0
14 (8.9%) 15 5 1
1
1
0 4*
3 4
1
I
1
1
aCulture-negative neutrocytic ascites. bNot included as an infection. *P < 0.05.
TABLE 2 Bacteria isolated in the several cultures Blood Urine AF Others Typeof infection Group I viridans
+
-
St. viridans
+
-
-
st.
viridans
-
-
+
st.
viridans
-
-
+
+
-
+
-
+ +
-
st.
s. aureus
Group II St. st.
viridans viridans a
Haemophilus Bacteroides
spa spa
st. pneumoniae
-
-
st. pneumoniae
+
-
s. aureus
-
-
Bacteremia Bacteremia SBP SBP Bacteremia
-
+
+ +
+b
Coagulase-neg. staphylococcusc +b
Peptoestreptococcus
sp
P. a e r u g i n o s a
+
bacteria isolated in the same blood culture. isolated from the local exudate. CCoagulase-negative staphylococcus. dThe two infections appeared in the same patient. aThree bBacteria
Bacterascites Pneumonia Pneumonia Pneumonia SBP SBP Pyopneumothorax Urinaryd Perineal abscessd SBP
263
LETTERS TO THE EDITOR
infections was 7% and 0.7%, respectively. These results support those previously observed in cirrhotic patients submitted to SID with norfloxacin (2,3) and show that the decrease in the incidence of bacterial infections in these patients is due to a lower incidence of infections caused by gram-negative bacilli. This may be explained by the high sensitivity of aerobic gram-negative bacilli to norfloxacin, whereas gram-positive cocci are less sensitive to this antibiotic. In addition, in our series the incidence of infection from gram-positive cocci was similar to that of cirrhotics belonging to the same high risk groups who did not undergo SID (3,4). This suggest that SID does not increase the incidence of infections due to norfloxacin-resistant bacteria. Antibiograms of the bacteria responsible for the infections showed that many of them were sensitive to amoxicillin/clavulanic acid, imipenem, vancomycin, cephalothin, cefotaxime and rifampicin. However, vancomycin and rifampicin are not usually considered suitable unless an infection due to methicillin-resistant staphylococcus is highly suspected. Imipenem is less selective than cefotaxime or amoxiciUin/clavulanic acid for bacteria normally involved in the infections of cirrhotics submitted to SID and is relatively more expensive.
In conclusion, the current study shows that cirrhotic patients submitted to SID with norfloxacin develop a low rate of infections, most of which are caused by gram-positive cocci. Amoxicillin/clavulanic acid or cefotaxime may be a suitable empiric antibiotic treatment when infection is suspected in these patients. Albert Tom~.s, Germfin Soriano, Carlos Guarner, Reinaldo Portorreal, Maria Teresa Novella and Francisco Vilardell Liver Section and Gastrointestinal Hemorrhage Unit, Department of Gastroenterology, Hospital de la Santa Creu i Sant Pau, Avinguda Sant Antoni Maria Claret, 167, 08025, Barcelona, Spain
References 1 2
3 4
Rimola A. Infecciones bacterianas en la cirrosis hep~itica. MTAMedicina Interna 1987; 5(4): 161-224. Gin6s P, Rimola A, Planas R, et al. Norfloxacin prevents spontaneous bacterial peritonitis recurrence in cirrhosis. Results of a double-blind placebo-controlled trial. Hepatology 1990; 12: 716-24. Soriano G, Guarner C, Teixid6 M, et al. Selective intestinal decontamination prevents spontaneous bacterial peritonitis. Gastroenterology 1991; 100: 477-81. Rimola A, Bory F, Ter6s J, P6rez-Ayuso RM, Arroyo V, Rodds J. Oral, nonabsorbable antibiotics prevent infection in cirrhotics with gastrointestinal hemorrhage. Hepatology 1985; 5: 463-7.
LETTERS TO THE EDITOR
HEPAT 01342
Hospital-acquired bacterial infections in patients with cirrhosis undergoing selective intestinal decontamination Cirrhotic patients show a higher incidence of hospitalacquired bacterial infections (17-35%) than the general hospital population (3-6%). Enteric aerobic gramnegative bacilli are the bacteria most frequently involved. Since bacterial infections in cirrhotic patients are re-
TABLE 1
lated to a poor prognosis and a low short-term survival rate, prophylaxis of infection is a logical approach and inhibition of enteric gram-negative bacilli by means of oral antibiotics has been proposed (1). Two controlled trials have demonstrated the useful-
Patients Numberof infections SBP CNNAa Bacterascitesb Bacteremia Respiratory Urinary Perinealabscess
ness of selective intestinal decontamination (SID) with oral norfloxacin in the prevention of bacterial infections in cirrhotic patients at high risk of infection (2,3). Interestingly, it seems that SID causes a change in the bacteria responsible for the infections in cirrhosis, since the bacteria most frequently isolated in treated patients from these two studies were gram-positive cocci instead of gram-negative bacilli. In the present study, hospital-acquired bacterial infections of 156 cirrhotic patients at high risk of infection undergoing SID with norfloxacin have been analyzed. Eighty-seven patients were hospitalized with ascites and ascitic fluid total protein < 1.5 g/dl (group I) and 69 patients were hospitalized because of gastrointestinal hemorrhage (group II). Patients from group I were treated with oral norfloxacin 400 mg/day during the entire hospitalization period and group II received 400 mg b.i.d, orally or through nasogastric tube during the first 7 days of hospitalization. Table 1 shows the 15 episodes of infection observed in 14 of the 156 patients, six with ascites (6.8%) and eight with gastrointestinal hemorrhage (11.5%). The incidence of infection was similar to that previously reported in patients belonging to the same groups at high risk submitted to SID and lower than in non-SID patients from other series (3,4). The bacteria responsible for the infections are listed in Table 2. Twelve infections were microbiologically proven (80%) and a total of 14 bacteria were isolated. Gram-positive cocci were present in 10 infections (66.6%), anaerobic bacteria in 2 (13.3%) and gramnegative bacilli in only one (6.6%). Therefore, the incidence of gram-positive cocci and gram-negative bacilli
Incidence (%) and source of infection in each group Group I (n = 87)
GroupII (n = 69)
Total (n = 156)
6 (6.8%) 6 2 1 0 3 0 0 0
8 (11.5%) 9 3 0
14 (8.9%) 15 5 1
1
1
0 4*
3 4
1
I
1
1
aCulture-negative neutrocytic ascites. bNot included as an infection. *P < 0.05.
TABLE 2 Bacteria isolated in the several cultures Blood Urine AF Others Typeof infection Group I viridans
+
-
St. viridans
+
-
-
st.
viridans
-
-
+
st.
viridans
-
-
+
+
-
+
-
+ +
-
st.
s. aureus
Group II St. st.
viridans viridans a
Haemophilus Bacteroides
spa spa
st. pneumoniae
-
-
st. pneumoniae
+
-
s. aureus
-
-
Bacteremia Bacteremia SBP SBP Bacteremia
-
+
+ +
+b
Coagulase-neg. staphylococcusc +b
Peptoestreptococcus
sp
P. a e r u g i n o s a
+
bacteria isolated in the same blood culture. isolated from the local exudate. CCoagulase-negative staphylococcus. dThe two infections appeared in the same patient. aThree bBacteria
Bacterascites Pneumonia Pneumonia Pneumonia SBP SBP Pyopneumothorax Urinaryd Perineal abscessd SBP
263
LETTERS TO THE EDITOR
infections was 7% and 0.7%, respectively. These results support those previously observed in cirrhotic patients submitted to SID with norfloxacin (2,3) and show that the decrease in the incidence of bacterial infections in these patients is due to a lower incidence of infections caused by gram-negative bacilli. This may be explained by the high sensitivity of aerobic gram-negative bacilli to norfloxacin, whereas gram-positive cocci are less sensitive to this antibiotic. In addition, in our series the incidence of infection from gram-positive cocci was similar to that of cirrhotics belonging to the same high risk groups who did not undergo SID (3,4). This suggest that SID does not increase the incidence of infections due to norfloxacin-resistant bacteria. Antibiograms of the bacteria responsible for the infections showed that many of them were sensitive to amoxicillin/clavulanic acid, imipenem, vancomycin, cephalothin, cefotaxime and rifampicin. However, vancomycin and rifampicin are not usually considered suitable unless an infection due to methicillin-resistant staphylococcus is highly suspected. Imipenem is less selective than cefotaxime or amoxiciUin/clavulanic acid for bacteria normally involved in the infections of cirrhotics submitted to SID and is relatively more expensive.
In conclusion, the current study shows that cirrhotic patients submitted to SID with norfloxacin develop a low rate of infections, most of which are caused by gram-positive cocci. Amoxicillin/clavulanic acid or cefotaxime may be a suitable empiric antibiotic treatment when infection is suspected in these patients. Albert Tom~.s, Germfin Soriano, Carlos Guarner, Reinaldo Portorreal, Maria Teresa Novella and Francisco Vilardell Liver Section and Gastrointestinal Hemorrhage Unit, Department of Gastroenterology, Hospital de la Santa Creu i Sant Pau, Avinguda Sant Antoni Maria Claret, 167, 08025, Barcelona, Spain
References 1 2
3 4
Rimola A. Infecciones bacterianas en la cirrosis hep~itica. MTAMedicina Interna 1987; 5(4): 161-224. Gin6s P, Rimola A, Planas R, et al. Norfloxacin prevents spontaneous bacterial peritonitis recurrence in cirrhosis. Results of a double-blind placebo-controlled trial. Hepatology 1990; 12: 716-24. Soriano G, Guarner C, Teixid6 M, et al. Selective intestinal decontamination prevents spontaneous bacterial peritonitis. Gastroenterology 1991; 100: 477-81. Rimola A, Bory F, Ter6s J, P6rez-Ayuso RM, Arroyo V, Rodds J. Oral, nonabsorbable antibiotics prevent infection in cirrhotics with gastrointestinal hemorrhage. Hepatology 1985; 5: 463-7.