Ventilatory support

Congenital myotonic dystrophy is a relatively rare condition in which myotonia (defined electrically) is mostly absent in the affected newborn infant, but becomes apparent in the older infant. Histopathology shows a consistent feature of arrested development and maturation of muscle fibers, but there is, currently, no adequate explanation for this phenomenon. Patients with congenital myotonic dystrophy rarely survive without aggressive ventilatory support, and survivors, without exception, are severely multiply handicapped. 

While selection of antimicrobial therapy may be a major consideration in treating infectious diseases, it may not be the only therapeutic intervention. Other important therapies may include adequate hydration, ventilatory support, and other supportive medications. In addition, antimicrobials are unlikely to be effective if the process or source that leads to the infection is not controlled. Source control refers to this process and may involve removal of prosthetic materials such as catheters and infected tissue or drainage of an abscess. Source-control considerations should be a fundamental component of any infectious diseases treatment. It is also important to recognize that there may be many different antimicrobial regimens that may cure the patient. While the following therapy sections... 

Additional doses of atropine and 2-PAMC1 depending on severity. Diazepam or lorazepam to prevent seizures if >4 mg atropine given ventilatory support. 

Disseminated histoplasmosis Acute (Infantile) Subacute Progressive histoplasmosis (immunocompetent patients and immunosuppressed patients without AIDS) 0.02-0.05 Disseminated histoplasmosis Untreated mortality 83% to 93% relapse 5% to 23% in non-AIDS patients therapy is recommended tor all patients Nonimmunosuppressedpatients Ketoconazole 400 mj day orally x 6-12 months or amphotericin B 35 mg/kg IV Immunosuppressed patients (non-AIDS) or endocarditis or CNS disease Amphotericin B >35 mg/kg x 3 months followed by fluconazole or itraconazole 200 mg orally twice daily x 12 months Life-threatening disease Amphotericin B 0.7-1 mg/kg/day IV for a total dosage of 35 mj kg over 2-4 months once the patient is afebrile, able to take oral medications, and no longer requires blood pressure or ventilatory support therapy can be changed to itraconazole 200 mg orally twice daily for 6-18 months Non-life-threatening disease Itraconazole 200-400 mg orally daily for 6-18 months fluconazole therapy 400-800 mg daily should be reserved for patients intolerant to itraconazole, and the development of resistance can lead to relapses... 

Noninvasive positive-pressure ventilation (NPPV) provides ventilatory support with oxygen and pressurized airflow using a face or nasal mask with a tight seal but without endotracheal intubation. In patients with acute respiratory failure due to COPD exacerbations, NPPV was associated with lower mortality, lower intubation rates, shorter hospital stays, and greater improvements in serum pH in 1 hour compared with usual care. Use of NPPV reduces the complications that often arise with invasive mechanical ventilation. NPPV is not appropriate for patients with altered mental status, severe acidosis, respiratory arrest, or cardiovascular instability. 

Respiratory disease Appropriate ventilatory support is the primary treatment of patients with serious lung disease who experience serious respiratory depression due to benzodiazepines rather than the administration of flumazenil. 

If there is reason to suspect a phosphorylating inhibitor was ingested or the patient is descending further into severe respiratory distress, treatment with an oxime might be warranted. However, if the patient s condition appears to be stable and adequate ventilatory support is available, it might be better to treat the patient symptomatically. 

MacIntyre NR, Cook DJ, Ely WE, Epstein SK, Eink JB, Heffner JE, Hess D, Hubmayer RD, Scheinhorn DJ (2001) Evidence-based guidelines for weaning and discontinuing ventilatory support. Chest 120(6) 375-395... 

Addicts use cocaine intravenously or by snorting the powder. After intravenous injections, coma and respiratory depression can occur rapidly. It has been reported that fatalities associated with snorting usually occur shortly after the abrupt onset of major motor seizures, which may develop within minutes to an hour after several nasal ingestions. Similar results occur if the substance is taken by mouth Treatment is directed toward ventilatory support and control of seizures—although in many instances a victim may not be discovered in time to prevent death. It is interesting to note that cocaine smugglers, who have placed cocaine-filled condoms in their rectum or alimentary tract, have died (Suarez et al.. 1977). The structural formula of cocaine is given in Fig 1. 

A 36-year-old HIV-infected woman who had been receiving stavudine, saquinavir, ritonavir, and didanosine developed lactic acidosis (serum lactate 11.4 mmol/1) and hepatomegaly. She had acute pancreatitis and, despite ventilatory support for respiratory failure, died after 8 weeks. 

Physiological Basis of Ventilatory Support, edited by J. J. Marini and A. S. Slutsky... 

Toronjadze T, Polena S, Santucci T, Naik S, Watson C, Lakovou C, Babury MA, Gintautas J. Prolonged requirement for ventilatory support in a patient with Eskalith overdose. Proc West Pharmacol Soc 2005 48 148-9. 

The safety of benzodiazepines in neonates has been assessed in a retrospective chart review of 63 infants who received benzodiazepines (lorazepam and/or midazolam) as sedatives or anticonvulsants (57). Five infants had hypotension and three had respiratory depression. In all cases of respiratory depression, ventilatory support was initiated or increased. Significant hypotension was treated with positive inotropic drugs in two cases. Thus, respiratory depression and hypotension are relatively common when benzodiazepines are prescribed in these patients. However, both depression and hypotension could also have been due to the severe underlying illnesses and concomitant medications. Matched controls were not studied. 

Pitfalls in the diagnosis of botulism include failure to recognize the symptoms and to institute adequate ventilatory support. Botulism is likely underdiagnosed and can be mistaken for a number of neuromuscular and neurologic disorders. Diphtheria, encephalitis, poliomyelitis, Guillain-Barre syndrome, congenital... 

The mainstays of botulism therapy include ventilatory support as well as the administration of botulinum antitoxin. Botulinum antitoxin is a trivalent, equine antitoxin that provides antibodies to botulinum toxin Types A, B, and E. It acts only against unbound toxin and therefore its efficacy is greatest early in the patient s clinical course. Cathartics and enemas have also been recommended for elimination of botulinum toxin from the GI tract. Antibiotics are not recommended except for the treatment of secondary infectious complications... 

Infantile Botulism—Ingestion ot botulism spores, often in honey, produces flaccid paralysis, poor feeding and suck reflexes, floppy baby syndrome. Wound Botulism—Contamination of wounds with C. botulinum spores can produce systemic symptoms. THERAPY Ventilatory support (often for weeks) Trivalent botulinum antitoxin Enemas and cathartics... 

Other clinical forms of the disease share many of these signs and symptoms. The presentation and duration of disease are coupled to the relative persistence of the toxin in blocking the release of ACh at peripheral nerve synapses. Although untreated botuhsm is potentially deadly, the availability of antiserum has dramatically reduced the mortality rates for the common clinical manifestations of the disease. Severe cases of foodbome botuhsm may still require ventilatory support for over a month, and neurological symptoms can sometimes persist for more than a year (Mackle et al, 2001). 

The overall treatment approach to nerve agent exposure focuses on airway and ventilatory support, aggressive use of antidotes (atropine and pralidoxime), prompt control of... 

Suxamethonium is destroyed by plasma pseudocholinesterase and so its persistence in the body is increased by neostigmine, which inactivates that enzyme, and in patients with hepatic disease or severe malnutrition whose plasma enzyme concentrations are lower than normal. Approximately 1 in 3000 of the European population have hereditary defects in amount or kind of enzyme, and cannot destroy the drug as rapidly as normal individuals. Paralysis can then last for hours and the individual requires ventilatory support and sedation until recovery occurs spontaneously. 

The accidental transformation of epidural to subarachnoid block can be dramatic, and tracheal intubation and ventilatory support may be necessary (102). Severe hypotension can result after inadvertent intrathecal local anesthesia (SEDA-21, 131). In women in labor, fetal bradycardia can occur. Postdural puncture headache can also be a sign of catheter migration. 

However, inadequate muscular activity requiring ventilatory support has been reported in babies born to mothers with atypical plasma cholinesterase. 

In addition, several autoimmune reactions to penicillamine can secondarily affect pulmonary function. PeniciUamine-induced polymyositis (56) or myasthenia gravis can cause respiratory failure, even requiring ventilatory support (57). The diagnosis and management of lupus-induced pleurisy have been reviewed (58). 

Effective treatment of polymyxin-induced neuromuscular blockade requires awareness of the complication, with appropriate supervision and immediate ventilatory support, if required. Calcium gluconate and neostigmine are not of proven efficacy and should not be relied on (11). 

Propofol caused marked prolongation of the QTc interval in a 71-year-old woman with an acute myocardial infarction who required ventilatory support (19). Substituting midazolam for propofol was associated with normalization of the QT interval. Rechallenge with propofol was associated with further prolongation. There were no malignant ventricular dysrhythmias. 

A 33-year-old man attempted suicide by selfinjection of strychnine intramuscularly (4). A few seconds after the first injection he developed dizziness and light-headedness. Ten minutes after the second injection he had seizures, opisthotonos, and tetany. He was rescued with a benzodiazepine and ventilatory support. 

Two 19-year-old-girls developed pulmonary edema after taking massive overdoses of verapamil (6000 mg and 7200 mg). In each case a chest X-ray showed diffuse bilateral patchy infiltration. Left ventricular size and function was normal on transthoracic echocardiography. They were both treated successfully with mechanical ventilatory support. 

If SE continues, proceed to phenobarbital. Patients who receive phenobarbital after being treated with IV benzodiazepines should be carefully monitored for respiratory depression and hypotension as the effects are additive. Ventilatory support should be immediately available. 

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