Intracranial pressure and cerebral perfusion pressure in experimental streptococcus pneumoniae meningitis.

Clinical studies have demonstrated the prognostic importance of increased intracranial pressure in central nervous system infections. To delineate development of intracranial pressure in meningitis experiments were carried out in rabbits. Meningitis was induced by injecting streptococcus pneumoniae bacteria into the cisterna magna and blood, and intracranial pressures were continuously recorded. In the experimental model, three stages were seen: incubation period (0-8 h)--in which CSF becomes positive for the infecting organism and biochemical changes occur, but there are no hemodynamic or intracranial pressure changes; stage of slowly increasing intracranial pressure - because blood pressure remains normal, cerebral perfusion pressure is maintained adequate for cerebral metabolic need (9-24 h); terminal stage (greater than 25 h)--with hemodynamic collapse, critical reduction of cerebral perfusion pressure, cerebral ischemia, and death of the experimental animals. It is suggested that a similar sequence occurs in human disease. The clinical implication stresses the need for early recognition and treatment of intracranial hypertension as an important adjunct to antibiotic treatment of the infecting organism.

Effect of endotracheal suctioning on arterial blood gases in children.

The occurrence of hypoxia during endotracheal tube suctioning and its prevention was examined in 25 hemodynamically stable and non-cyanosed pediatric patients. In each patient 4 suction and treatment protocols were studied: 1. pre- and post-suction arterial blood gases (ABG) with no treatment (control). 2. ABG with pre-suction oxygenation. 3. ABG with presuction hyperinflation. 4. ABG with postsuction hyperinflation. With no presuction treatment the PO2 and saturation fell significantly after suctioning from control level of 116.6 +/- 9.4 mmHg to 93 +/- 9.3 mmHg post-suction and 97.2 +/- 0.4% to 92.8 +/- 1.4% (p less than 0.001) respectively. In 6 patients with low but adequate pre-suction PO2, hypoxic levels (PO2 less than 60 mmHg) were found post-suction. The significant fall in PO2 was completely prevented by pre-suction oxygenation. Post-suction hyperinflation induced a rapid return of the PO2 to control levels. These results suggest that severe hypoxia might occur during endotracheal suctioning and can be prevented by pre-oxygenation. We recommend 1 min oxygenation with FiO2 1.0 prior to suctioning procedures and intermittent hyperinflation with 100% oxygen during repeated endotracheal suction passes to prevent hypoxia, especially in children in respiratory failure who already have low or borderline pre-suction PO2.

Prolonged electrocerebral silent barbiturate coma in intractable seizure disorders.

Barbiturate coma (BC) is a known modality for terminating resistant convulsive status epilepticus. It is usually applied until seizure activity ends. We recently adopted a modified protocol of prolonged, electrocerebral silent BC to treat patients with chronic seizure activity resistant to multiple regimens of antiepileptic drugs. Four patients, aged 4 months to 10 years, with long-standing intractable generalized seizures were treated. Seizure frequency ranged from one to two to numerous times per day. Following BC, one patient has been seizure free during 8 months of follow-up, and another has had only two seizures in 18 months. A 4-month-old infant was seizure-free for 2 weeks after BC and then died from underlying CNS disease. A 10-year-old girl died during BC from shock and hyperpyrexia. The results obtained in our patients indicate that prolonged electrocerebral silent BC may exert a beneficial long-term effect in treatment of intractable seizure disorders. This procedure might also be beneficial in other forms of epilepsy.

Arhinia revisited.

Arhinia is a rare anomaly in which a total absence of the nose and parts of the olfactory system occurs. It is frequently associated with various multiple central nervous system (CNS) and somatic anomalies of different degrees of severity, with high mortality rate. Twelve cases that have been reported in the literature are analyzed according to multiple criteria. The anomalies that have been found to be associated with arhinia are: lack of olfactory bulbs and nerves, missing paranasal sinuses, high arched or cleft palate, various eye anomalies, low set ears - all in a very high incidence. Various degrees of CNS malformations have been found in part of the cases. Somatic anomalies have been reported in 50% of the cases. In two cases chromosome 9 anomalies have been reported. A classification is suggested in which arhinia is classified into arhinia (total absence of the nose and rhinencephalon) and partial arhinia (partial absence of the nose), each may or may not be associated with other malformations (facial, CNS and somatic).

Scoring system to assess disease severity in children.

A scoring system to assess disease severity in children, based on therapeutic and diagnostic interventions, is suggested. The charts of 475 consecutive admissions to a multidisciplinary pediatric intensive care unit (PICU) were reviewed and therapeutic and diagnostic interventions (TDI) associated with more than 20% mortality identified. These were scored: TDI associated with 20-30% mortality - 1 point; 31-40% - 2 points; 41-50% - 3 points and more than 51% - 4 points. According to these values, a Pediatric Therapeutic and Diagnostic Intervention Score (PTDIS) was calculated for each patient. The study population may be divided, according to PTDIS and mortality, into three groups: moderately severe disease associated with up to 2.7% mortality and PTDIS less than 20; severe disease associated with up to 25% mortality and PTDIS less than 35; critically ill patients with more than 50% mortality and PTDIS greater than 36. PTDIS in survivors was 15.2 +/- 0.6 (mean +/- SE) and 43.6 +/- 1.1 in non-survivors. Pearson's correlation between PTDIS and mortality was R = 0.7162 at a significance level of p less than 0.0001. PTDIS and mortality were not found to be significantly correlated with sex, age or duration of hospitalization in the Unit. Sepsis, central nervous system infections and burns were the primary diseases, and shock, coma and patients after cardiopulmonary resuscitation the indications for admission to the Unit, associated with the highest mortality and PTDIS. This study demonstrates the efficacy of the suggested PTDIS system in accurately assessing severity of disease in a PICU patient population.

An unusual case of non-traumatic pneumococcal mediastinal abscess.

A 16-month old baby developed severe respiratory failure because of acute laryngitis and required mechanical ventilation. Intubation was complicated by aspiration and development of chemical pneumonia. Following 4 days of treatment the child was successfully extubated. Thirty six hours after extubation the patient again developed respiratory failure and on chest X-ray pneumomediastinum was seen and later evidence of a mediastinal abscess. Conservative treatment, with antibiotics, effected complete cure.

Incidence of aspiration in endotracheally intubated infants and children.

A prospective study is reported to examine the incidence of aspiration in 50 infants and children intubated with a noncuffed endotracheal tube in a multidisciplinary PICU. Aspiration was assessed by applying Evans blue dye on the tongue and searching for the dye during suctioning, in the endotracheal aspirate. Twenty-nine (58%) were medical patients and 21 (42%) surgical; ages ranged between 25 h and 4 yr (mean 18.5 months). Respiratory failure was the major indication for endotracheal intubation and mechanical ventilation in 26 (52%) of the patients, hyperventilation for increased intracranial pressure in 12 (24%), congestive heart failure in 8 (16%), and protection of airway in deeply comatose patients in 4 (8%). The patients remained intubated from 18 h to 12 days (mean 70.4 h). Evidence of aspiration was found in 8 (16%) of the patients, accompanied by changes in chest x-ray in 5 (63%) patients and a significant fall in PO2 in 3 (37%). Aspiration was not significantly affected by the presence of a nasogastric tube, level of consciousness or ventilator setting. We conclude that noncuffed endotracheal tubes of proper size that adequately seal the trachea and effectively prevent clinically significant aspiration in endotracheally intubated infants and children.

Cerebral perfusion pressure and auditory brain-stem responses in childhood CNS diseases.

Intracranial hypertension, complicating CNS diseases of childhood, reduces effective cerebral perfusion pressure (CPP) with resultant cerebral ischemia. The auditory brain-stem evoked response (ABR) is an important diagnostic tool that enables evaluation of brain-stem function and prognostication during the acute stage of the illness. We studied CPP and ABRs in 25 infants and children with CNS infection and cerebral ischemia. In all survivors, CPP could be maintained above 30 mm Hg, and the ABR remained normal or with partial pathology. In nonsurvivors, CPP could not be maintained above this level, and the ABR waves were completely absent. Long-term outcome was not correlated with the minimal CPP recorded during the disease or with examination of the ABR.

Cerebral perfusion pressure in central nervous system infections of infancy and childhood.

Central nervous system infections may be complicated by development of severe brain edema, which can be a significant factor in mortality and morbidity. Increased intracranial pressure can cause additional damage to the central nervous system by impairment of cerebral blood flow, which is dependent on cerebral perfusion pressure. A reduction of cerebral perfusion pressure, caused by elevation of intracranial pressure, may cause cerebral ischemia. We studied cerebral perfusion pressure in 17 patients, ages 45 days to 11 years, with severe central nervous system infections and who were in deep coma. Meningitis was diagnosed in 64.7%, and encephalitis in 29.4%. The patients who survived (64.7%) did not differ significantly from those who died (36.5%) in severity of disease and maximal intracranial pressure during the course of the illness. A striking difference in minimal cerebral perfusion pressure recorded was found between survivors and nonsurvivors: all patients with minimal cerebral perfusion pressure greater than 30 mm Hg survived, whereas those with lower pressure died. In survivors, cerebral perfusion pressure could be maintained adequately by reduction of intracranial pressure, but nonsurvivors developed noncompliance of brain tissue, and cerebral perfusion pressure could not be maintained at levels that ensure adequate cerebral blood flow, resulting in cerebral ischemia and death. Continuous monitoring of mean arterial blood pressure and intracranial pressure in children with severe central nervous system infections will enable rapid diagnosis and initiation of treatment when cerebral perfusion pressure is reduced to critical levels. Such treatment might improve the prognosis.

Treatment of status epilepticus with thiopentone sodium anaesthesia in a child.

A 4-month-old infant was admitted to the Pediatric Intensive Care Unit with Pneumococcal meningitis. A few hours after admission he developed intractable convulsions that could not be stopped with phenytoin, phenobarbitone and a continuous drip of diazepam. Thiopentone sodium anaesthesia was induced for 24 h terminating the status epilepticus. The clinical course, correlary EEG findings, treatment protocol and blood levels of the drugs given are described in detail.

Intracranial pressure in central nervous system infections and cerebral ischaemia of infancy.

Intracranial pressure was continuously monitored in 23 patients aged between 24 hours and 20 months. Fourteen had severe infections of the central nervous system (CNS) and 9 sustained prolonged cerebral ischaemia. The intracranial pressure measured at catheter placement was not a reliable indicator of the intracranial pressure that developed during the course of the disease. The mean maximal intracranial pressure in infants with CNS infection (57.4 +/- 25.8 mmHg) was significantly higher than in infants with cerebral ischaemia (34.6 +/- 17.6 mmHg). Mortality in CNS infections (36%) was closely correlated with the degree of increased intracranial pressure, while mortality in cerebral ischaemia (67%) was not. Continuous monitoring of intracranial pressure enables treatment to be started early so that intracranial pressure can be reduced and adequate cerebral perfusion pressure maintained. This may help to reduce morbidity and mortality.

Diagnostic and prognostic value of auditory nerve brainstem evoked responses in comatose children.

The efficacy of auditory nerve brainstem evoked response (ABR) in the diagnosis and localization of brainstem lesions and its prognostic value in determining outcome were examined in 30 deeply comatose children. The ABR recordings obtained from each patient were correlated with the clinical, ancillary examinations and final outcome of these children. Clinical and ancillary examinations indicated damage to the cerebrum alone in 14 patients. In these children, ABR was found to be within normal limits. Isolated brainstem lesion was suggested by these examinations in 4 patients and their ABR recording showed absence of one or more of the brainstem response wave components or a prolonged brainstem transmission time (BTT). In 12 patients, damage to both the cerebrum and brainstem was suspected by clinical and laboratory examinations. In 8 patients, partial absence of brainstem waves or prolonged BTT was found. In 4, there was complete absence of all brainstem waves. All patients, regardless of etiology or depth of coma, with normal ABR, survived. Conversely, all children with complete absence of brainstem response waves succumbed. The prognosis of patients with partial absence of brainstem waves or prolonged BTT was variable. Some survived while others remained in a vegetative state or died. Our study demonstrates the importance of ABR in the diagnosis and localization of brainstem lesions and its value as a prognosticator of outcome in deeply comatose children.

Intracranial pressure during prolonged experimental convulsions in cats.

Experiments were carried out in cats to examine the relationship between prolonged convulsions and intracranial pressure. The convulsions were induced by pentylenetetrazole or bicuculline. Blood pressure, intracranial pressure and electroencephalogram were continuously monitored. Generalized tonic-clonic convulsions appeared with typical changes in the electroencephalogram 7-35 s after administration of the epileptogenic drugs. These convulsions persisted for 1-2 h. Concomitant with the clinical convulsions, intracranial pressure increased three- to fivefold, reaching maximal pressures of 20-94 mm Hg after 20-420s. The intracranial pressure remained high for between 47 s and 10 min, then began to fall gradually, reaching preictal levels after 2-30 min despite the continuation of convulsions. The variations in intracranial pressure were found to be independent of changes in blood pressure. The intracranial pressure, after dropping to preictal values, remained unchanged for up to 6 h after the induction of convulsions.

Incidence of convulsions and encephalopathy in childhood Shigella infections. Survey of 117 hospitalized patients.

Of 117 children ill enough to be hospitalized with Shigella gastroenteritis, 53 per cent had neurologic symptoms, the majority during the onset of high fever: 11 per cent had convulsions alone, 22 per cent had encephalopathy alone, and 20 per cent had convulsions and encephalopathy. The neurologic manifestations preceded the gastrointestinal symptoms in one fourth of the patients. Shigella sonnei was the predominant organism found in this study, especially in patients with neurologic symptoms.