Intra-aortic balloon counterpulsation: augmentation of cerebral blood flow after aneurysmal subarachnoid haemorrhage.

OBJECTIVE: To measure cerebral blood flow before and after intra-aortic balloon counterpulsation (IABC) in patients at high risk of developing delayed cerebral ischaemia after aneurysm surgery following subarachnoid haemorrhage. METHODS: Six prospectively selected patients at high risk of developing delayed ischaemia had elective IABC after clipping of their cerebral aneurysm(s). The IAB inflates in early diastole and deflates at the end of diastole to increase cardiac perfusion and decrease afterload. This results in enhanced cardiac efficiency. It also augments cerebral blood flow (CBF). RESULTS: We demonstrated a significant increase in the mean hemispheric CBF from the preoperative (preIABC) value of 35.6 mls/100 g/min to 50.9 +/- 12.3 mls/100 g/min (p = 0.0042) as a result of balloon augmentation. Each patient developed a neurological deficit as a result of delayed cerebral ischaemia. These were reversed in 5 patients with increased CBF. There were minimal balloon related complications. CONCLUSION: IABC consistently enhanced CBF in these patients and resulted in stable cardiovascular parameters. This represents a possible new technique in the management of cerebral ischaemia following subarachnoid haemorrhage and needs further assessment to ascertainlits role.

Traumatic cerebrospinal fluid leakage: risk factors and the use of prophylactic antibiotics.

Cerebrospinal fluid (CSF) leakage following head trauma is often difficult to diagnose, but is of considerable importance in view of the possibility of fistula formation and meningitis. It is unclear whether specific clinical or radiological signs point to an increased risk of CSF leakage. Previous studies have been largely anecdotal and uncontrolled, leading us to perform a retrospective control study comparing the clinical and radiological features of patients with overt CSF leakage, and those without. Of the 293 patients studied, 115 had clinical CSF leakage and 170 did not, with incomplete documentation in eight patients. The group with CSF rhinorrhoea had significantly greater incidence of periorbital haematoma (chi square = 8.642). This suggests that patients with head injuries and features of periorbital haematoma are at greater risk of unobserved dural tear and delayed CSF leakage. Frontal and ethmoid fractures in particular were also associated with CSF leakage (chi square = 5.46). The use of prophylactic antibiotics was studied. There was a significantly greater incidence of meningitis in the group which received prophylactic antibiotics (p = 0.024). There was no significant difference in the incidence of meningitis in those patients with CSF fistulae treated by surgical or conservative methods.

Combined aztreonam and gentamicin therapy for pseudomonal lower respiratory tract infections.

A multicenter, open-label study was performed to assess the efficacy and safety of aztreonam plus gentamicin in the treatment of lower respiratory tract infections due to Pseudomonas aeruginosa. Patients with documented P aeruginosa infections were given aztreonam 2 g every 8 hours (q8h) plus gentamicin 3 to 5 mg/kg per day in three equal doses. Clindamycin, 600 mg q8h, was added to the regimen for patients with infections also involving gram-positive and/or anaerobic bacteria. Therapy was continued for at least 5 days or until obvious failure to respond to treatment. Of 64 patients with suspected P aeruginosa infections, 57 were eligible for clinical evaluation and 51 for microbiologic evaluation. At entry, impaired host defense was present in 35% of patients, and chronic obstructive pulmonary disease in 28%, in addition to other predisposing conditions such as emphysema, history of tuberculosis, and pneumothorax. The clinical response rate for the combination regimen was 48/57 (84%), which included 27 (47%) cures and 21 (37%) partial responses. The microbiologic response rate was 35/51 (69%), of which 25 (49%) outcomes were classified as eradication and 10 (20%) as eradication with relapse. Superinfection was observed in 3 (6%) patients. The combination of aztreonam and gentamicin was synergistic in the initial isolates obtained from 33 (72%) patients. A total of 16 patients died of pulmonary or other underlying disease, for a mortality rate of 28%. The monobactam-aminoglycoside combination was generally well tolerated. Two other patients were withdrawn because rashes emerged on treatment. This study demonstrates that aztreonam can be administered as one component of a synergistic monobactam-aminoglycoside therapy in the treatment of nosocomial lower respiratory tract infections involving P aeruginosa.

The Trinidad and Tobago coup of July 1990: a surgeon's view - abstract

The Coup of July, 1990, was a unique disaster in Trinidad. It lasted six (6) days, most of the violent actions occurred in Port-of-Spain and resulted in an unprecedented number and variety of injuries being brought to the General Hospital, Port-of-Spain. This study examines the number and type of injuries seen, and the mortality and management aspects at the hospital during the diaster. Three doctors kept daily records of casualty attendance, admission, types of injuries, circumstances surrounding the injury and treatment. Over the 6 days, 560 patients were seen at the Accident and Emergency Department. Of these 302 were admitted, 250 were treated and discharged (of the 50 were coup-related), and 8 died. There were 187 surgical admissions of which 170 were coup-related and 107 injuries were due to gunshots. Of 231 persons injured as a result of the coup, 133 (58 percent) were looters. Extraordinary efforts were required to cope with the overwhelming demands on the staff and hospital facilities. The unique nature of the calamity exposed areas of weakness in our disaster plan. Special circumstances such as the curfew and catering for large numbers of staff over a prolonged period needed specific attention. Effective comunication between the disaster area and health care facilities has to be established. Hospital specialist should participate in the planning for such a disaster (AU)

Induction of effective immunity to Moloney murine sarcoma virus using monoclonal anti-idiotypic antibody as immunogen.

We have isolated an anti-idiotypic mAb (RS1.1.3), which recognizes an idiotope present on several IgM mAb specific for Moloney murine leukemia virus (M-MuLV)-determined cell surface Ag. The binding of RS1.1.3 to idiotypic antibody could be inhibited by specific Ag. Intraperitoneal immunization of mice with purified RS1.1.3 antibody-induced effective immunity against Moloney murine sarcoma virus challenge. A single injection of RS1.1.3 7 days before virus challenge resulted in a 27% reduction in tumor load compared to non-immune control mice challenged with the same dose of virus, whereas multiple injections of RS1.1.3 before virus challenge resulted in a 75% reduction in tumor load. The protective effect of anti-idiotype immunization appeared to be T dependent, because immunization of athymic mice had no effect on their susceptibility to tumor virus challenge. Administration of the anti-idiotypic antibody after virus inoculation caused an increase in tumor load of nearly 50% compared to non-immune controls. BALB/c mice immunized with RS1.1.3 developed anti-anti-idiotypic antibodies, as well as M-MuLV Ag-specific antibodies. Analysis of sera from RS1.1.3-immune mice subsequently challenged with Moloney murine sarcoma virus indicated an inverse relationship between tumor load and M-MuLV-specific serum IgG titers induced by the RS1.1.3 immunization. These results indicate that anti-idiotypic mAb may be used as immunogen to induce Ag-specific antibody responses, and to cause effective immunity to a retro-virus-induced tumor.

Activation of a functional idiotype network response by monoclonal antibody specific for a virus (M-MuLV)-induced tumor antigen.

BALB/c mice were injected with IgM mAb specific for Moloney murine leukemia virus (M-MuLV)-determined cell surface Ag in an attempt to inhibit Moloney sarcoma growth. The monoclonal IgM significantly inhibited sarcoma growth when given to the mice after inoculation with Moloney murine sarcoma/leukemia virus, and also potentiated the in vivo antibody response specific for M-MuLV Ag. These responses were significantly greater than the primary response to the virus alone in age- and sex-matched control mice, and were also seen in mice which were injected with the IgM antibody only and not with virus, suggesting that an Ag-independent mechanism may be involved. The M-MuLV-specific serum antibody responses induced by the monoclonal IgM, with or without prior virus inoculation, were predominantly of the IgG1 isotype, with some IgG2a; no other isotypes were found to have titers significantly higher than in the normal response to virus alone. M-MuLV-specific IgG1 was detected only in mice injected with monoclonal IgM, and not in the response to virus alone. The same sera also had high titers of anti-idiotypic antibodies, (Ab2), as well as anti-anti-idiotypic antibodies (Ab3). It appears, therefore, that passive immunization with M-MuLV-specific IgM mAb activates an idiotypic network, which results in both Ab2 and Ab3 responses; the M-MuLV-specific response may be considered a subset of Ab3.