The role of Vitamin B12 in the critically ill--a review.

Vitamin B12 is an essential micronutrient, as humans have no capacity to produce the vitamin and it needs to be ingested from animal proteins. The ingested Vitamin B12 undergoes a complex process of absorption and assimilation. Vitamin B12 is essential for cellular function. Deficiency affects 15% of patients older than 65 and results in haematological and neurological disorders. Low levels of Vitamin B12 may also be an independent risk factor for coronary artery disease. High levels of Vitamin B12 are associated with inflammation and represent a poor outlook for critically ill patients. Treatment of Vitamin B12 deficiency is simple, but may be lifelong.

Increased Vitamin B12 levels are associated with mortality in critically ill medical patients.

BACKGROUND & AIMS: We describe an observational study in critically ill medical patients showing the association between serum Vitamin B12 levels measured on or near admission and the outcome in these patients. METHODS: We used the database of patients admitted to the Medical Intensive Care Unit (MICU) at the Hadassah-Hebrew University Medical Center in Jerusalem, Israel, to analyze associations between patient demographics, background, diagnoses and serum Vitamin B12 levels with hospital and 90 day outcomes. RESULTS: Higher mean Vitamin B12 levels were found in patients who did not survive their hospital stay (1719 pg/ml vs 1003 pg/ml, p < 0.01). Those who had died by 90 days after admission to the MICU also had higher Vitamin B12 levels than survivors (1593 pg/ml vs 990 pg/ml). Regression analysis showed that elevated Vitamin B12 levels were associated with increased 90 day mortality, even after controlling for other variables. Survival analysis also showed an increased mortality rate in patients with Vitamin B12 levels over 900 pg/ml (p < 0.0002). CONCLUSIONS: Our data show that high serum Vitamin B12 levels are associated with increased mortality in critically ill medical patients. We suggest that Vitamin B12 levels should be included in the work-up of all medical intensive care patients, particularly those with a chronic health history and increased severity of illness.

Adaptive Support Ventilation as the sole mode of ventilatory support in chronically ventilated patients.

OBJECTIVE: To describe the outcome of patients admitted to a new private facility for chronically ventilated patients in the Ashdod area of Israel. METHODS: On arrival, all patients were placed on Adaptive Support Ventilation (ASV) at 90% of target minute ventilation for lean body weight, reducing progressively in weekly decrements of 10% down to 60% of target minute ventilation if adequate spontaneous ventilation was maintained by the patient. RESULTS: Almost half (12/27) of these patients admitted in the first 12 months following establishment of the facility were successfully weaned from mechanical ventilation within 2 weeks to 2 months of admission. CONCLUSIONS: The cost effectiveness of this form of closed loop mechanical ventilation in achieving weaning automatically, without the need for respiratory therapists or continuous attendance by intensive care specialists to conduct weaning trials is demonstrated by these results.

Non-invasive Mechanical Ventilation Enhances Patient Autonomy in Decision-Making Regarding Chronic Ventilation.

OBJECTIVE: Patients with respiratory failure due to progressive muscle weakness often require chronic ventilatory support, but many do not make decisions regarding ventilation prior to a crisis. We studied the use of non-invasive ventilation as a tool to enable communication and facilitate decision-making regarding chronic ventilation. METHODS: Patients with profound muscle weakness and acute respiratory failure, were supported or weaned by non-invasive positive or negative pressure ventilation. The patients were then interviewed and their informed autonomous decisions were used to plan their future management. RESULTS: Non-invasive ventilation could be used safely to support patients with acute respiratory failure until decisions regarding chronic ventilation are made and as an alternative means of ventilation for those who refuse tracheostomy. CONCLUSIONS: Non-invasive ventilation may be used in patients with profound muscle weakness, as a means of enhancing patient autonomy by improving communication and maintaining ventilation until decisions about ongoing care are made.

Cuirass ventilation: a review and update.

OBJECTIVE: This review highlights the development and application of modern chest wall cuirass ventilators. DATA SOURCES: Initial animal studies and subsequent publications of applications of various modes of noninvasive cuirass ventilation are recorded. SUMMARY OF REVIEW: Use of the modern cuirass ventilator in continuous negative, intermittent negative or biphasic (negative and positive) modes is described. Techniques of synchronisation of the cuirass ventilation to the patient's inspiratory and expiratory demands, or even to the patient's cardiac cycle are described. Use of noninvasive cuirass ventilation at normal physiological respiratory rates and at high frequency is highlighted in published studies and in the authors' clinical practice in intensive care. Case reports of patients with cardiac, respiratory and neurological diseases having been successfully managed are used in the review to highlight the desirability, versatility and safety of noninvasive cuirass ventilation for optimal patient care in selected cases. CONCLUSIONS: Cuirass ventilation is a valid and valuable method of ventilation in a subset of patients as illustrated by the case reports in this review. Future possibilities for the use of noninvasive cuirass ventilation including in emergency situations where expertise for endotracheal intubation is unavailable; or where physicians or paramedics are unlikely to be able to intubate unconscious/paralysed patients quickly enough to save their lives (e.g. in biological or chemical warfare situations).

Severe influenza infection in a chronic hepatitis C carrier: failure of protective serum HI antibodies after IM vaccination.

BACKGROUND: Influenza is an important cause of morbidity and mortality in immunocompromised hosts. Recommendations exists for vaccination each year, yet disease can still occur. OBJECTIVES: To describe the course of fulminant influenza infection in a patient with HCV. STUDY DESIGN: Case study in which correlation was made between immunoglobulin response to influenza vaccination to the disease and its unique clinical course caused by influenza virus. RESULTS: Influenza A/Jerusalem 17/98 (H(1)N(1)) was isolated from the throat of a chronic hepatitis C carrier who, presented with shortness of breath, and subsequent massive bilateral pneumonia. The patient was previously immunized IM with inactive influenza vaccine. He developed protective levels of humoral antibodies (1:80 hemagglutination inhibition (HI) antibodies) against the three strains of the vaccine that evidently did not prevent respiratory infection. The development of massive bilateral pneumonia and continued presence of influenza virus in the respiratory tract may have been due to his underlying medical condition and possible lack of mucosal secretory IgA (SIgA) antibodies. CONCLUSION: We have presented a case of prolonged influenza infection post vaccination. This case emphasizes the importance of an improved vaccine that would stimulate a better immunologic response, especially in immunocompromised patients.

Adaptive lung ventilation.

Adaptive lung ventilation (ALV) is a method of closed-loop mechanical ventilation analogous to modern closed-loop technology in aviation such as the autopilot and automatic landing system. The algorithm of the controller of ALV is designed to automatically provide pressure-controlled synchronized intermittent mandatory ventilation (P-SIMV) and weaning as individually required in any clinical situation. The synchronized pressure limited breaths constantly adapt to the patient requirements to encourage optimal alveolar ventilation with minimal adverse physiological disturbance and timely weaning. The ease of application, efficiency, and safety of the first ALV controllers have been demonstrated in lung models, in patients with normal lungs undergoing general anesthesia, in patients requiring unusual positioning, in transition to and from one-lung anesthesia, and in long-term ventilation of patients with various lung pathologies and in weaning patients who have restrictive or obstructive pulmonary disease. Prospective comparative studies of ALV versus other currently used manually selected modes of mechanical ventilation, such as the one reported in this article, should confirm the safety and identify the benefits of this form of advanced closed-loop mechanical ventilation technology.

Plasmapheresis for thrombotic thrombocytopenic purpura following bone marrow transplantation.

Recognition of thrombotic thrombocytopenic purpura (TTP)/hemolytic uremic syndrome (HUS) following bone marrow transplantation (BMT) has increased in recent years. The use of plasma exchange has greatly improved the outlook of de novo TTP. Fewer data are available on its use in post-BMT TTP but small uncontrolled series showed poor results with low response rates. We present here a case of a young patient who developed manifestations of TTP 10 months after BMT with complete recovery following treatment with plasma exchange for 1 month. This case suggests that plasma exchange could be life saving and should be tried in every patient with post-BMT TTP.

Ticlopidine-induced thrombotic thrombocytopenic purpura.

Thrombotic thrombocytopenic purpura (TTP) occurs in association with a wide variety of disorders including infections, connective tissue diseases, and solid organ tumors. It also may coincide with administration of drugs such as mitomycin, metronidazole, oral contraceptives, cyclosporine, and many others. We report the occurrence of TTP in a patient shortly after the initiation of ticlopidine.

Severe necrotizing pancreatitis caused by organophosphate poisoning.

Pancreatitis secondary to organophosphate insecticide toxicity is rare and is believed to follow a subclinical and uneventful course. We report two cases of severe acute pancreatitis complicated by pancreatic necrosis and retroperitoneal sepsis in which the diagnosis was obscured by the systemic effects of organophosphate toxicity. Awareness of this complication should prompt earlier investigation because early diagnosis coupled with timely therapeutic measures may improve patient prognosis.

Fatal Capnocytophaga canimorsus (DF-2) septicaemia. A case report.

A 45-year-old man died 2 months after being bitten on the hand by a dog. He developed the rare but characteristic clinical picture of fulminant septicaemia and peripheral gangrene caused by a Gram-negative bacillus, Capnocytophaga canimorsus, previously known as dysgonic fermenter type 2 (DF-2), which is an occasional commensal in the oral flora of dogs and cats. This disease must be anticipated and dog bites appropriately managed to avoid the mortality associated with infection by this micro-organism. Initial treatment includes appropriate prophylactic antibiotics and debridement, while early exchange transfusion and emergency amputation may be of value in fulminant cases.