Bacteremia, Lumbar Punctures, and Meningitis punctures (LPs) Howshould lumbar performed during
many hosbe pitalization for proper management of a case of meningitis? To date this question has not been answered to ev-
eryone's satisfaction. However, a new
dilemma concerning LP and meningitis has arisen. This is related to the need for a second LP to make an initial diagnosis of meningitis. Fischer and his associates, elsewhere in this issue (see page 590), as well as Rapkin,1 have reported a number of cases of meningitis in which the cerebrospinal fluid CSF obtained on the initial LP was essentially normal. A second LP, at times performed only a few hours later, disclosed purulent fluid. A common denominator in many of these cases was a positive blood culture that was obtained on admission to the hospital. These observations led to the conclusion that "a positive blood culture mandates a repeat LP,"1 particularly in small infants according to Fischer et al (page
590).
If there were no hazards associated with the procedure of LP, the ques¬ tion of a mandatory second LP would be moot. However, LP is an invasive procedure and, as such, has been asso¬ ciated with infection,2albeit rare, epi¬ thelial rests resulting in neoplasms,3·4 and cardiorespiratory arrest, partic¬ ularly in pediatrie patients with car¬ diac or pulmonary disease.5
Another theoretic hazard associ¬ ated with LP has been raised by the experimental work of Petersdorf et al.6 They produced meningitis in dogs by performing a cisternal puncture after the animals had been given a large inoculum of bacteria intrave¬ nously. The importance of their ob¬ servation as related to human infec¬ tion has been questioned primarily because it was believed that bacteremic patients rarely achieved an intravascular bacterial count as high as those utilized in the meningitis stud¬ ies in dogs. However, recent observa¬ tions suggest that these concentra¬ tions of bacteria are commonly seen in neonatal septicemia.7 It was also noted that the higher the concentra¬ tion of bacteria in the blood, the more likely the association of meningitis. However, it is not clear whether an LP performed during bacteremia in humans is pathogenetically associ¬ ated with meningitis. In one study, the incidence of meningitis in chil¬ dren who had an LP during the course of pneumococcal bacteremia was no greater than in bacteremic patients who did not have a prior CSF exami¬ nation.8 In the face of these observations, the question reasonably may be asked, does bacteremia imply the probable association of meningitis? Metastatic deposition of bacteria on the men¬ inges is not an inevitable conse-
Downloaded From: http://archpedi.jamanetwork.com/ by a New York University User on 06/02/2015
quence of bacteremia. Whether
or
not
patient develops meningitis de¬ pends on a number of factors, includ¬ ing the nature of the host, the num¬ bers of circulating organisms, and the type of organism involved. For ex¬ ample, Haemophilus influenzae bac¬ teremia associated with epiglottitis, otitis media, tracheobronchitis, or other foci of infection is usually not followed by meningitis.9 Other orga¬ nisms such as Diplococcus pneu¬ a
monias may cause febrile illness and bacteremia without localized infec¬ tion or meningitis.1" It seems reason¬ able to conclude, therefore, that the mere presence of bacteremia does not justify an LP in every case, but that the procedure should be done when meningitis is suspected. In infants, on the other hand, Gramnegative bacteremia is frequently as¬ sociated with meningeal infection.11·12 Recent evidence by McCracken et al suggests that an important factor in this situation is the virulence of the invading organism.13 They have clearly shown that some strains of Escherichia coli are more invasive than others. Signs and symptoms of disease are frequently absent in the newborn infant with meningeal in¬ fection. Therefore, in these patients the burden is on the clinician to prove the absence of meningitis. Is a second LP mandatory when the initial tap shows normal CSF and the
patient is known to have bacteremia?
While a second LP under these cir¬ cumstances must seriously be consid¬ ered, the decision should be made on the basis of all available data, includ¬ ing a careful clinical appraisal of the patient's condition. It should be em¬ phasized that clinical features may mandate a second LP a few hours later and before the result of the blood culture is available (page 590).' Moreover, recovery of purulent CSF on a second LP following an initial negative LP may be found in the absence of concomitant bacteremia (page 590). Another caveat involving LP and meningitis includes those cases in which the CSF is clear but does indeed contain bacteria.14 It is clear that the pediatrician should not be satisfied with normal results from a single LP to exclude meningitis—especially when the pa¬ tient has bacteremia. Pediatricians are not reluctant to do an initial tap when indicated. It is well to remem-
ber that in some situations an addi¬ tional LP may be required for proper diagnosis and treatment. HENRY R. SHINEFIELD, MD Department of Pediatrics Permanente Medical Group 2200 O'Farrell St San Francisco, CA 94115 References 1. Rapkin RH: Repeat lumbar punctures in the diagnosis of meningitis. Pediatrics 54:34-37, 1974. 3. Findlay L, Kemp FH: Osteomyelitis of the spine following lumbar puncture. Arch Dis Child 18:102-105, 1943. 3. Choremis C, Economos D, Papadatos D, et al: Intraspinal epidermoid tumours (cholesteatomas) in patients treated for tuberculous meningitis. Lancet 2:437-439, 1956. 4. Shaywitz BA: Epidermoid spinal cord tumors and previous lumbar punctures. J Pediatr 80:638-640, 1972. 5. Margolis CZ, Cook CD: Risk of lumbar puncture in pediatric patients with cardiac and/or pulmonary disease. Pediatrics 51:562-564, 1973. 6. Petersdorf RG, Swarner DR, Garcia M: Studies on the pathogenesis of meningitis: II. Development of meningitis during pneumococcal bacteremia. J Clin In-
Second
41:320-327, 1962. 7. Dietzman Fischer DE, GW, Schoenknecht FD: Neonatal Escherichia coli septicemia: Bacterial counts in blood. J Pediatr 85:128-130, 1974. 8. Pray LG: Lumbar puncture as a factor in the pathogenesis of meningitis. Am J Dis Child 62:295-308, 1941. 9. McGowan JE, Klein JO, Bratton L, et al: Meningitis and bacteremia due to influenzae: Occurrence and Haemophilus mortality at Boston City Hospital in 12 selected years, 1935-1972. J Infect Dis 130:119-124, 1974. 10. McGowan JE, Klein JO, Findland M: Bacteremia in febrile children seen in a "walk-in" pediatric clinic. N Engl J Med vest
288:1309-1312,
1973.
11. Johnston RB, Sell SH: Septicemia in infants and children. Pediatrics 34:473-479, 1964. 12. Buetow KC, Klein SW, Lane RB: Septicemia in premature infants: The characteristics, treatment, and prevention of septicemia in premature infants. Am J Dis Child 110:29-41, 1965. 13. McCracken GH, Sarr LD, Glode M, et al: Relationship between Escherichia coli K 1 capsular polysaccharide antigen and clinical outcome in neonatal meningitis. Lancet 2:246-250, 1974. 14. Moore CM, Ross M: Acute bacterial meningitis with absent or minimal cerebrospinal fluid abnormalities. Clin Pediatr
12:117-118, 1973.
Writing: V. As previously stated, medical writing is—or ought to be—for readers. And the con¬ struction of paragraphs may offer a greater opportunity to assist the reader than the Thoughts
on
Medical
structure of their individual sentences.
Division of composition into paragraphs is not merely a means of telling the reader where to take a physical or mental breath. Nor is it just a device for pleasantly varying the right and left margins of the printed page. While it does confer both these benefits, it is, more fundamentally, the writer's signal of a slight change: to a different aspect of his subject, such as a difference of place, person, thing, time, to name but a few of the more obvious. The difference may be very slight, but the sign of it encourages the reader. For it tells him he is going somewhere, has turned a corner, is making progress. But unless this expectation is borne out by what the first few lines of the new para¬ graph suggest to him, his hope of progress will be short-lived. The opening sentence of a paragraph, therefore, should somehow indicate, sometimes explicitly, perhaps better implicitly, the new subject. Similarly, the closing sentence of the paragraph may well hint at least that something, however small, has been dealt with. We shall have more to say about this next month. Paragraphs, thus, are of themselves small compositions, whose beginning and ending sentences (and those intervening between) offer the reader some evidences of progress within each of these small units. A useful test of your writing, as you create and recre¬ ate the necessary succession of drafts, is to examine them paragraph by paragraph, first for unity and then, sentence by sentence, for progress, asking yourself about each: "Does this sentence get me anywhere?" You may equally well ask: "Is this sentence necessary?" If the answer to either question is "No," the sentence should be deleted. This may be painful but there are few better ways of improving a manuscript—or a
grant application.
C. A. Smith
Downloaded From: http://archpedi.jamanetwork.com/ by a New York University User on 06/02/2015
many hosbe pitalization for proper management of a case of meningitis? To date this question has not been answered to ev-
eryone's satisfaction. However, a new
dilemma concerning LP and meningitis has arisen. This is related to the need for a second LP to make an initial diagnosis of meningitis. Fischer and his associates, elsewhere in this issue (see page 590), as well as Rapkin,1 have reported a number of cases of meningitis in which the cerebrospinal fluid CSF obtained on the initial LP was essentially normal. A second LP, at times performed only a few hours later, disclosed purulent fluid. A common denominator in many of these cases was a positive blood culture that was obtained on admission to the hospital. These observations led to the conclusion that "a positive blood culture mandates a repeat LP,"1 particularly in small infants according to Fischer et al (page
590).
If there were no hazards associated with the procedure of LP, the ques¬ tion of a mandatory second LP would be moot. However, LP is an invasive procedure and, as such, has been asso¬ ciated with infection,2albeit rare, epi¬ thelial rests resulting in neoplasms,3·4 and cardiorespiratory arrest, partic¬ ularly in pediatrie patients with car¬ diac or pulmonary disease.5
Another theoretic hazard associ¬ ated with LP has been raised by the experimental work of Petersdorf et al.6 They produced meningitis in dogs by performing a cisternal puncture after the animals had been given a large inoculum of bacteria intrave¬ nously. The importance of their ob¬ servation as related to human infec¬ tion has been questioned primarily because it was believed that bacteremic patients rarely achieved an intravascular bacterial count as high as those utilized in the meningitis stud¬ ies in dogs. However, recent observa¬ tions suggest that these concentra¬ tions of bacteria are commonly seen in neonatal septicemia.7 It was also noted that the higher the concentra¬ tion of bacteria in the blood, the more likely the association of meningitis. However, it is not clear whether an LP performed during bacteremia in humans is pathogenetically associ¬ ated with meningitis. In one study, the incidence of meningitis in chil¬ dren who had an LP during the course of pneumococcal bacteremia was no greater than in bacteremic patients who did not have a prior CSF exami¬ nation.8 In the face of these observations, the question reasonably may be asked, does bacteremia imply the probable association of meningitis? Metastatic deposition of bacteria on the men¬ inges is not an inevitable conse-
Downloaded From: http://archpedi.jamanetwork.com/ by a New York University User on 06/02/2015
quence of bacteremia. Whether
or
not
patient develops meningitis de¬ pends on a number of factors, includ¬ ing the nature of the host, the num¬ bers of circulating organisms, and the type of organism involved. For ex¬ ample, Haemophilus influenzae bac¬ teremia associated with epiglottitis, otitis media, tracheobronchitis, or other foci of infection is usually not followed by meningitis.9 Other orga¬ nisms such as Diplococcus pneu¬ a
monias may cause febrile illness and bacteremia without localized infec¬ tion or meningitis.1" It seems reason¬ able to conclude, therefore, that the mere presence of bacteremia does not justify an LP in every case, but that the procedure should be done when meningitis is suspected. In infants, on the other hand, Gramnegative bacteremia is frequently as¬ sociated with meningeal infection.11·12 Recent evidence by McCracken et al suggests that an important factor in this situation is the virulence of the invading organism.13 They have clearly shown that some strains of Escherichia coli are more invasive than others. Signs and symptoms of disease are frequently absent in the newborn infant with meningeal in¬ fection. Therefore, in these patients the burden is on the clinician to prove the absence of meningitis. Is a second LP mandatory when the initial tap shows normal CSF and the
patient is known to have bacteremia?
While a second LP under these cir¬ cumstances must seriously be consid¬ ered, the decision should be made on the basis of all available data, includ¬ ing a careful clinical appraisal of the patient's condition. It should be em¬ phasized that clinical features may mandate a second LP a few hours later and before the result of the blood culture is available (page 590).' Moreover, recovery of purulent CSF on a second LP following an initial negative LP may be found in the absence of concomitant bacteremia (page 590). Another caveat involving LP and meningitis includes those cases in which the CSF is clear but does indeed contain bacteria.14 It is clear that the pediatrician should not be satisfied with normal results from a single LP to exclude meningitis—especially when the pa¬ tient has bacteremia. Pediatricians are not reluctant to do an initial tap when indicated. It is well to remem-
ber that in some situations an addi¬ tional LP may be required for proper diagnosis and treatment. HENRY R. SHINEFIELD, MD Department of Pediatrics Permanente Medical Group 2200 O'Farrell St San Francisco, CA 94115 References 1. Rapkin RH: Repeat lumbar punctures in the diagnosis of meningitis. Pediatrics 54:34-37, 1974. 3. Findlay L, Kemp FH: Osteomyelitis of the spine following lumbar puncture. Arch Dis Child 18:102-105, 1943. 3. Choremis C, Economos D, Papadatos D, et al: Intraspinal epidermoid tumours (cholesteatomas) in patients treated for tuberculous meningitis. Lancet 2:437-439, 1956. 4. Shaywitz BA: Epidermoid spinal cord tumors and previous lumbar punctures. J Pediatr 80:638-640, 1972. 5. Margolis CZ, Cook CD: Risk of lumbar puncture in pediatric patients with cardiac and/or pulmonary disease. Pediatrics 51:562-564, 1973. 6. Petersdorf RG, Swarner DR, Garcia M: Studies on the pathogenesis of meningitis: II. Development of meningitis during pneumococcal bacteremia. J Clin In-
Second
41:320-327, 1962. 7. Dietzman Fischer DE, GW, Schoenknecht FD: Neonatal Escherichia coli septicemia: Bacterial counts in blood. J Pediatr 85:128-130, 1974. 8. Pray LG: Lumbar puncture as a factor in the pathogenesis of meningitis. Am J Dis Child 62:295-308, 1941. 9. McGowan JE, Klein JO, Bratton L, et al: Meningitis and bacteremia due to influenzae: Occurrence and Haemophilus mortality at Boston City Hospital in 12 selected years, 1935-1972. J Infect Dis 130:119-124, 1974. 10. McGowan JE, Klein JO, Findland M: Bacteremia in febrile children seen in a "walk-in" pediatric clinic. N Engl J Med vest
288:1309-1312,
1973.
11. Johnston RB, Sell SH: Septicemia in infants and children. Pediatrics 34:473-479, 1964. 12. Buetow KC, Klein SW, Lane RB: Septicemia in premature infants: The characteristics, treatment, and prevention of septicemia in premature infants. Am J Dis Child 110:29-41, 1965. 13. McCracken GH, Sarr LD, Glode M, et al: Relationship between Escherichia coli K 1 capsular polysaccharide antigen and clinical outcome in neonatal meningitis. Lancet 2:246-250, 1974. 14. Moore CM, Ross M: Acute bacterial meningitis with absent or minimal cerebrospinal fluid abnormalities. Clin Pediatr
12:117-118, 1973.
Writing: V. As previously stated, medical writing is—or ought to be—for readers. And the con¬ struction of paragraphs may offer a greater opportunity to assist the reader than the Thoughts
on
Medical
structure of their individual sentences.
Division of composition into paragraphs is not merely a means of telling the reader where to take a physical or mental breath. Nor is it just a device for pleasantly varying the right and left margins of the printed page. While it does confer both these benefits, it is, more fundamentally, the writer's signal of a slight change: to a different aspect of his subject, such as a difference of place, person, thing, time, to name but a few of the more obvious. The difference may be very slight, but the sign of it encourages the reader. For it tells him he is going somewhere, has turned a corner, is making progress. But unless this expectation is borne out by what the first few lines of the new para¬ graph suggest to him, his hope of progress will be short-lived. The opening sentence of a paragraph, therefore, should somehow indicate, sometimes explicitly, perhaps better implicitly, the new subject. Similarly, the closing sentence of the paragraph may well hint at least that something, however small, has been dealt with. We shall have more to say about this next month. Paragraphs, thus, are of themselves small compositions, whose beginning and ending sentences (and those intervening between) offer the reader some evidences of progress within each of these small units. A useful test of your writing, as you create and recre¬ ate the necessary succession of drafts, is to examine them paragraph by paragraph, first for unity and then, sentence by sentence, for progress, asking yourself about each: "Does this sentence get me anywhere?" You may equally well ask: "Is this sentence necessary?" If the answer to either question is "No," the sentence should be deleted. This may be painful but there are few better ways of improving a manuscript—or a
grant application.
C. A. Smith
Downloaded From: http://archpedi.jamanetwork.com/ by a New York University User on 06/02/2015
