SIMPLE ASPIRATION OF PNEUMOTHORAX

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REDUCING CONSULTATIONS FOR UPPER RESPIRATORY INFECTIONS GENERAL practitioners spend far too much time dealing with coughs and colds and other minor upper respiratory symptoms. Many strategies have been devised for preventing unnecessary consultations but few have so far been tested objectively. Now Roberts and co-workers,’ from the family medicine care centre of the University of Missouri, Columbia, have reported a controlled randomised trial of a health education programme designed to decrease unnecessary consultation for upper respiratory tract infections in a fee-for-service clinic. The first step was to establish criteria of need for a consultation, and this was done by a panel of three family doctors, one paediatrician, one physician, and one health educator. They recommended consultation for patients over the age of two years with a symptom cluster that suggested either a diagnosis other than an upper respiratory infection or an indication for drug therapy: the agreed criteria incorporated severity and duration of fever, rhinorrhoea, sore throat, a combination of all three, and various other symptoms. Families attending the clinic, comparable in demographic characteristics and prealternately to the study consultation rates, -were study and the control group-443 to the former and 444 to the latter. For the control families no action was taken apart from the usual clinical care, whereas adult members of the study group were interviewed by specially trained health educators who instilled into them the concept of responsibility for personal and family care. They were then given an educational package consisting of information about the common cold and how to treat it, as well as a symptom-based algorithm that listed the following indications for a consultation: temperature above 103°F, bad pain in the chest, head, stomach, ears, or glands in the neck; shortness of breath or wheezing; sore throat getting worse with a temperature of 101 ° F for 24 h; sore throat with a temperature above 100°F for 48 h; temperature above 100°F for 3 days; fever, sore throat, or rhinorrhoea for a full week. They were also given an oral thermometer and told that they could consult their doctor if they felt the need, even if their symptoms did not conform to the algorithm. Consultations by both study and control group families were monitored for the next 11-17 months and classified by two independent family doctors and a health educator, according to the predetermined criteria, as either necessary or unnecessary. On review, the study families proved to have made 44% fewer unnecessary consultations than the controls and 15% fewer necessary ones. The total of upper respiratory infections recorded, including those associated with other conditions, was 29% less in the study families, and there was no compensating increase in consultations for respiratory complications. Consultation rates for other respiratory diseases and for otitis media were identical in the two groups. Roberts and co-workers compare their study with two others, both in pre-paid insurance plan group practices. The results from the first, in Seattle, suggest that explicit criteria may actually increase consultation for upper respiratory infections, but the Seattle criteria for a consultation were different in that 77% were classified as necessary in contrast to the 60% of Roberts et al. There was no educational intervention and the patients in the practice were already participating in a virus watch for which they kept health diaries subject to bi-weekly inspection, which may well have

assigned

1. Roberts

CR, Imrey PB, Turner JD, Hosokawa MC, Alster JM. Reducing physician through consumer education. JAMA 1983; 250: 1986-90.

visits for cold

increased the likelihood of contact with a doctor. The other report was from a group practice near Sacramento using the same algorithms as Seattle, and again without personal educational input; there was no significant reduction in consultations for upper respiratory infections. Would Columbia’s educational package and algorithms reduce unnecessary consultations elsewhere? It is difficult to know because there are so -many imponderables. Did Columbia succeed where Seattle and Sacramento failed because it was a fee-for-service clinic (thus providing a financial incentive not to consult) or was the interview with a health educator the vital factor in success? If it was the interview, which averaged a mere 5 minutes, general practitioners themselves might find it time-effective in the long run to do it themselves. Many patients who cannot get an immediate appointment will readily accept a doctor’s advice about treatment over the telephone; but for those who repeatedly attend with upper respiratory infections an algorithm could be helpful to one and all.

SIMPLE ASPIRATION OF PNEUMOTHORAX WHEN

a spontaneous pneumothorax occupies more than of lung volume, or is big enough to cause dyspnoea, air must be evacuated from the pleural cavity by intercostal

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intubation and underwater seal drainage.’-4 This, at least, is the policy in most hospitals, and its efficacy cannot be questioned; but is such an aggressive approach necessary? Emerson5recommended that, if there is no evidence of tension or persisting broncho-pleural fistula, the air should be aspirated with a pneumothorax machine. Unfortunately few hospitals have such a device, and in those that do it will probably be gathering dust in the rooms of one of the more mature physicians-a memento of bygone days. Now Hamilton and Archersuggest that a 60 ml plasticsyringe will serve almost as well. A 16-gauge intravenous cannula is inserted through the chest wall under local anaesthesia and connected to the syringe via a 3-way tap. Air is then aspirated and expelled through plastic tubing with its end in a jug of sterile water (so that air is seen to be leaving the pneumothorax). Hamilton and Archer tried this method in 10 patients with "uncomplicated" pneumothorax admitted in the course of twelve months, the indications being continuing symptoms or a chest X-ray showing more than 30% lung deflation. (Tension pneumothorax apart, they do not say what they mean by "complicated".) In 9 patients the pneumothorax was spontaneous and in 1 it was a complication of central venous pressure line insertion. The treatment was judged successful in 7 patients though 2 of them required two procedures and another 2 required three. The remaining 3 patients eventually had intercostal intubation with underwater seal drainage. A 7007o success rate for this simple treatment is superficially impressive, but the report could usefully have included

1. Home NW. Spontaneous pneumothorax: diagnosis and management. Br Med J 1966; i: 281-84. 2. Read AE, Barritt DW, Langton Hewer R. Modern medicine. A textbook for students. Tunbridge Wells: Pitman Medical, 1979. 3. Crompton GK. Diagnosis and management of respiratory diseases. Oxford: Blackwell, 1980. 4. Crofton J, Douglas A. Respiratory diseases. Oxford: Blackwell, 1981. 5. Emerson P. Thoracic medicine. London: Butterworths, 1981. 6. Hamilton AAD, Archer GJ. Treatment of pneumothorax by simple aspiration. Thorax 1983; 38: 934-36.

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information on duration of hospital admission, especially for the 4 patients who had to be treated more than once and, more importantly, how long intercostal intubation was delayed in those unsuccessfully treated by the syringe method. Nevertheless, the fact that 70% of this small group were spared intercostal intubation must make us question use of intercostal catheter drainage in all patients with uncomplicated pneumothoraces requiring treatment. The introduction of a Malecot or Argyle intercostal catheter should be painless, but on occasions is not; when in place, a catheter can cause severe continuing discomfort; and removal, especially of selfretaining catheters, can be very painful indeed. Advocates of routine intercostal intubation declare that a prime objective is to create adhesions which help prevent recurrence. Does this really happen? If creation of adhesions is the objective, might this not be better done by routine kaolin insufflation ? Perhaps all pneumothoraces that do not respond to treatment by simple aspiration as described by Hamilton and Archer should have kaolin pleurodesis (preferably done by a surgeon, under general anaesthesia). Another argument is that, with aspiration, the visceral pleura may be lacerated by the needle;’ but this clearly does not apply if a small plastic cannula is used. Simple aspiration of a pneumothorax leaves no scars, physical or psychological, and should be evaluated as firstline treatment for uncomplicated pneumothoraces. This management is, of course, not suitable for traumatic pneumothorax and those complicated by tension or large amounts of pleural liquid. Pneumothoraces occurring in patients being ventilated, or even those being considered for assisted ventilation, must be treated by intercostal intubation and underwater seal drainage.

MENINGITIS: ASEPTIC OR PYOGENIC? A PATIENT who arrives in hospital with a diagnosis of meningitis is quite likely to have received antibiotics for a day or more. Such early treatment is associated with a good

outcome,1 but the association may not be causal: the chance of treatment may be greater in those whose of slow onset. Although the clinical picture may be

receiving home

disease is altered by antibiotics, the experienced physician usually has little difficulty in deciding whether the meningitis is bacterial or aseptic (viral). Clinical pointers are the mode and speed of onset, level of consciousness, presence of haemorrhagic or other septicaemic signs, and general severity of symptoms; and the cerebrospinal fluid (CSF) is likely to show typical changes even if bacteria are not seen on the gram-stained films. In a small proportion of patients, however, including some who have received antibiotics, no such clear distinction can be made. Two hazards then arise-failure to continue or initiate treatment in a case of bacterial meningitis; and, less important, unnecessary treatment with antibiotics. In bacterial meningitis two chemical features are a reduction of CSF/blood glucose ratio and an increase of CSF protein. Other potentially useful indicators are CSF lactate, aminoacid, and pH. Bland and co-workers2 measured lactic acid and pH in aseptic, purulent, and partly treated cases: for both indices the values were low, intermediate, and high,

respectively. The protein concentration was also high in the intermediate cases (mean 209 mg/dl) and low in the aseptic group, and seemed to give as much information as the lactate and pH. Bland et al claimed that a decreasing lactic acid concentration indicated effective therapy and resolution. The same can usually be said for decreasing levels of protein. Briem3has investigated 53 patients, mostly adults, with proven bacterial meningitis untreated before admission, 102 patients with aseptic meningitis, and 108 controls, none of whom had infections of the nervous system. With an arbitrary discrimination limit of 115 µmol/l the CSF lactate proved to be the most sensitive and the most efficient chemical test with no false negatives in the bacterial cases, although 4 patients with aseptic meningitis had false positives. These 4 patients all had herpetic infections-3 due to herpes simplex virus and 1 to cytomegalovirus. 53 patients had a repeat CSF examination 24-48 h after admission, the 34 with bacterial meningitis having received antibiotics during this time. The lactate test was appreciably less sensitive at this time than before treatment, whereas a test for aminoacids had increased in sensitivity and efficiency. The rise in aminoacids at this stage is thought to be due not to leakage from plasma but to deranged metabolism of local tissue.4 Its value lies in persistence when cell counts, sugar, protein, and lactate are all tending to become normal. (In an earlier study of 185 CSF specimens from children, Rutledge and his colleagues5 judged that lactate determination gave no additional information. Indeed they believed that, if reliance had been placed on it, several children would have been treated unnecessarily. Their controls, unlike those in other series, included patients with other central nervous system diseases.) How important are these additional tests in clinical practice? In a review of 171 cases of bacterial meningitis Ispahani6 points out that, although pre-admission antibiotic therapy can change the cell count, type of cellular response, and protein and glucose concentrations of CSF, it is unlikely to alter all of the variables substantially and the low glucose characteristic of pyogenic meningitis is often retained. In difficult cases lactate and aminoacid measurements do have a small part to play. In Briem’s series lactate was the most efficient chemical test in the untreated case and was raised above the discrimination limit in all cases of bacterial aetiology. It is noteworthy that the four false-positive tests were all from patients with herpetic infections (2 with severe meningoencephalitis). Maybe a raised CSF lactate will prove a helpful pointer to herpetic neurological illness when other findings exclude a bacterial cause. Viral cultures from the CSF can also help in differential diagnosis, positive cultures 7 being obtained in some instances within two or three days. In partly treated patients a raised aminoacid concentration is highly suggestive of bacterial infection, 3,4,8 whereas lactate concentration depends largely on the duration and dose of 2 antibiotic, the decrease parallelling the fall in the cell count. Comparison between cerebrospinal fluid concentrations of glucose, total protein, chloride, lactate and total amino acids for the differential diagnosis of patients with meningitis. Scand J Infect Dis 1983; 15: 277-84. 4. San Joaquin VH, Khai N, Seale TW, Rennert OM. Increased cerebrospinal fluid free ammo acid concentrations in children with bacterial meningitis. Scand J Infect Dis 1982; 14: 23. 5. Rutledge J, Benjamin D, Hood L, Smith A. Is the CSF lactate measurement useful in 3. Briem H.

the management of children with suspected bacterial meningitis. J Pediatr 1981; 98: Ruckley CV, McCormack RJM. The management of spontaneous pneumothorax. Thorax 1966; 21: 139-44. 1. McKendrick GDW. The treatment of pyogenic meningitis. J Neurol Neurosurg Psychiatry 1968; 31: 528-31. 2. Bland RD, Lister RC, Ries JP. Cerebrospinal fluid lactic acid level and pH in meningitis: aids in differential diagnosis. Am J Dis Child 1974; 128: 151. 7.

20. 6. Ispahani P. Bacterial meningitis in Nottingham. J Hyg 1983; 91: 189-201. 7. Editorial. Viral cultures from cerebro-spinal fluid. Lancet 1982; ii: 250-51. 8. Briem H, Hultman EH, Kalin ME, Lundbergh PR. Increased total concentration of amino acids in the cerebro-spinal fluid of patients with purulent meningitis. J Infect Dis 1982; 145: 346.