Feeding the intensive care patient

The present review highlights recent findings (focusing on papers published between October 1999 and December 2000) in nutritional support of intensive care unit patients. During the past year, research focused on the use of enteral nutrition versus parenteral nutrition, and on the best composition of enteral nutrition and parenteral nutrition according to the clinical condition of the patient. With regard to enteral nutrition, the pH of nutritional support, the timing of administration and the technique of tube placement were debated. Immunomodulating agents and hormonal manipulations may improve outcomes of critically ill patients, but still warrant further research before they can be recommended for routine clinical use.     

Vascular access for dialysis in the intensive care unit

Management of the vascular access (VA) for renal replacement therapy (RRT) in acute renal failure (ARF) patients is faced with a twofold problem: first, the creation of an angio-access that is adequate for RRT in the acute setting; second, the preservation of the patient's vascular network in order not to preclude further use of the vessel in the event of evolution to chronic renal failure. Central venous catheters are the preferred VA for RRT in the intensive care setting. Semi-rigid double-lumen polyurethane catheters may be considered for short-time use (up to 2-3 weeks). Soft silicone double-lumen or twin-catheters, preferably with subcutaneous tunnelling, are highly desirable for prolonged RRT (over 3 weeks). The femoral route is the first option in the presence of associated risk factors (respiratory failure, pulmonary oedema, bleeding...). The internal jugular route should be considered for mid-term use in order to facilitate the patient's mobilization and to reduce the risk of infection. The subclavian route should be avoided because of the risk of stenosis and/or thrombosis of the outflow vein. Catheter insertion must be performed by a trained physician with ultrasound guidance using either skin mapping or continuous vein guidance. Catheter handling and care should comply with best practice guidelines and should be part of a continuous quality improvement programme in order to reduce catheter-related morbidity. Preservation of the upper limb vascular network of the patient consists of sparing the native vessels (artery and vein) of the patient and preserving the functionality of the permanent VA in chronic renal failure patient. This 'lifeline' of chronic renal failure patients may be maintained by preventing inflammation, infection and thrombosis of the superficial vessels of the arm and forearm of patient.     

Diagnostic laparoscopy in the intensive care patient

Summary Evaluation of a potential acute abdomen in patients who require intensive care for concurrent medical/surgical problems is often difficult due to ambiguities in the physical exam and ancillary diagnostic tests. Between August 1990, and February 1992, 25 ICU patients underwent diagnostic laparoscopy to evaluate a suspected acute intraabdominal process. Thirteen laparoscopies were negative, and 12 were positive. The overall accuracy for laparoscopy was 96% as confirmed by subsequent laparotomy, autopsy, or clinical course. Laparoscopic findings led to a change in management in nine patients (36%), leading to earlier exploration in four patients, and avoidance of laparotomy in five. No significant hemodynamic effects were noted during laparoscopy, and the procedure-related morbidity was low (8.0%).Diagnostic laparoscopy is a safe and accurate guide for managing the ICU patient with a suspected acute surgical abdomen. The use of laparoscopy can help avoid nontherapeutic laparotomy or confirm the need for operative intervention in these complex cases.     

Liver intensive care for the general intensivist

Liver injury or failure is observed in up to 20% of patients admitted to the intensive care unit and is associated with poor prognosis. Timely recognition and initiation of appropriate management are the most important steps in minimising adverse outcome for patients. Distinguishing between primary or secondary liver failure, and between acute or chronic liver disease aids appropriate management. This can be challenging in cases of limited history and delayed or protracted presentation. Liver failure should be considered as a multisystem disease, with numerous systemic manifestations that must be considered to optimise supportive intensive care unit care. In this narrative review, we summarise an approach to patients with deranged liver biochemistry admitted to a general intensive care unit. We focus on interpretation of patterns of deranged liver biochemistry and the necessary investigations required to identify the related aetiologies. We also propose an evidence-based approach to the management of liver failure and its extrahepatic manifestations. This review, in addition, clarifies when to seek expert advice or refer patients to a tertiary centre.     

Management of the airway in intensive care

Airway management in intensive care is often routine; however there is a higher incidence of problems with a difficult airway that is under-reported. Management of these patients is by a multidisciplinary team who may have less familiarity and experience to manage the difficult airway than that which is commonly found in the operating theatre environment. In this article we explain the predictable and unpredictable aspects of airway management in this important group of patients. Particular emphasis is placed on the specific problems associated with extubation in the ICU and there is detailed discussion of the aspects of multiple organ failure that are commonly experienced in the critically ill patient and the impact they have on airway management. Problems with oxygen delivery and ventilation/perfusion mismatch are touched upon. The important role of early tracheostomy in the management of the complex airway in ICU is addressed in some detail. We also address the importance of non-technical skills, rehearsal and planning to increase the safe and effective management of airway problems in the critically ill. We provide generic suggestions for the drugs and equipment immediately required to optimise the safe management of these patients.     

Management of the airway in intensive care

Airway management in the intensive care unit (ICU) is largely uneventful; there is a higher incidence of airway difficulties, however, than those encountered in the operating suite. Management of the airway in the ICU presents challenges unique to this environment that must be coped with by a multidisciplinary team that may be less experienced in airway management than clinicians in the operating theatre. The risks associated with this situation, I believe, may be ameliorated by planning and forethought. This article outlines some of the specific difficulties faced by clinicians in ICU and attempts to provide some guidance as to how these may be overcome, or at least abated. Drug choices are discussed, as are equipment choices. A suggestion for a difficult airway algorithm for use in the ICU is put forward. The timing of tracheostomy is discussed. Finally, the importance of the team and the human factors that are at play are touched upon.     

Management of the airway in intensive care

Airway management in the intensive care unit (ICU) is largely uneventful; there is a higher incidence of airway difficulties, however, than those encountered in the operating suite. Management of the airway in the ICU presents challenges unique to this environment that must be coped with by a multidisciplinary team that may be less experienced in airway management than clinicians in the operating theatre. The risks associated with this situation, we believe, may be ameliorated by planning and forethought. This article outlines some of the specific difficulties faced by clinicians in ICU and attempts to provide some guidance as to how these may be overcome, or at least abated. Drug and equipment choices are discussed. A suggestion for a difficult airway algorithm for use in the ICU is put forward. The timing of tracheostomy is discussed. Finally, the importance of the team and the human factors that are at play are touched upon.     

The polytrauma patient in the intensive care unit

Patients admitted to an intensive care unit with the diagnosis "polytrauma" differ from other patients by their typical trauma-associated morbidity (diffusive bleeding, traumatic brain injury, lung contusion), and by the staged surgical treatment of multiple injuries. The complexity of the clinical picture, and the complexity of the chronological order of the operative phases require a close cooperation of the medical specialist disciplines involved. The perioperative morbidity and mortality of polytrauma victims has been reduced significantly within the last 30 years due to an adapted transfusion- and substitution regime (rational utilization of anemia tolerance, calculated substitution of coagulation factors), due to modern therapeutic regimes for the patient with traumatic brain injury (stabilization of cerebral perfusion pressure, stabilization of adequate cerebral oxygenation), and due to the modern therapeutic strategies of mechanical ventilation (lung-protective ventilation, kinetic therapy, non-invasive ventilation). The aim of this review is to describe these modern therapeutic principles of the intensive care unit treatment of the polytrauma patient.     

Bedside diagnostic minilaparoscopy in the intensive care patient

BACKGROUND: The diagnosis of acute abdominal conditions in the critically ill patient remains difficult. The goal of this study is to demonstrate the use of bedside minilaparoscopy as a diagnostic aid in the intensive care unit (ICU) in patients with possible intra-abdominal catastrophic condition. METHODS: Between February 1998 and May 1999, intensive care patients with abdominal pain, unexplained acidosis or sepsis, or suspected mesenteric ischemia were eligible for bedside diagnostic minilaparoscopy (3.3-mm laparoscope and instruments). The procedure was performed at bedside in the ICU with the patient under local anesthesia and intravenous sedation. Pneumoperitoneum was established with nitrous oxide (N(2)O) to a pressure of 8 to 10 mm Hg. Hemodynamics and ventilatory parameters were monitored before, during, and after the procedure. RESULTS: Nineteen patients underwent bedside diagnostic minilaparoscopy, including 1 patient who underwent 2 diagnostic laparoscopies. Total procedure time was 9 to 68 minutes (mean, 21 minutes). Three patients were found to have extensive mesenteric ischemia and did not undergo laparotomy. One patient found to have questionably viable bowel at laparoscopy underwent a nontherapeutic formal laparotomy. One patient had a gangrenous gallbladder, and another had a small ischemic segment of bowel; each underwent later open laparotomy and resection. The remaining laparoscopic examinations either showed a nonsurgical cause for the patient's condition or were normal. Nontherapeutic laparotomy was avoided in 19 of 20 patients. One gallbladder perforation occurred during laparoscopy in a patient with a necrotic gallbladder. CONCLUSIONS: Bedside minilaparoscopy can be a safe and accurate method to evaluate critically ill patients in whom the possibility of mesenteric ischemia or other intra-abdominal process is entertained. Nontherapeutic laparotomy can be avoided in many critically ill patients. Bedside diagnostic laparoscopy can be a useful replacement for diagnostic laparotomy in the operating room. It should be included in the diagnostic algorithm in the evaluation of the unstable patient in the ICU with a suspected acute intra-abdominal process.     

Propofol-induced hyperamylasaemia in a general intensive care unit

This study examined the incidence of hyperamylasaemia, in the absence of other plausible causes of pancreatic dysfunction, in intensive care unit (ICU) patients who received propofol. One-hundred-and-seventy-two consecutive patients of a general ICU who stayed for more than 24 hours were studied. Patients with a diagnosis consistent with elevated serum amylase levels at admission were excluded from the study, as were patients who had received medications known to raise serum amylase levels. Forty-four patients 53 +/- 20 years of age and median duration of ICU stay of five days (range two to 55) were eligible. Thirty of those, aged 54 +/- 21 years and median duration of ICU stay of five days (range two to 27) received continuous infusion of propofol for sedation (maximum dose 45 microg/kg/min). Of the 30 patients who received propofol, 16 (53%) developed hyperamylasaemia (125 to 466 IU/l) after two to nine days of continuous infusion. Liver and kidney function remained normal throughout the observation period. Of the 14 patients who did not receive propofol (aged 51 +/- 18 years), only two (14%) developed hyperamylasaemia, a significantly lower incidence (P = 0.021). Propofol infusion is associated with biochemical evidence of pancreatic injury. Amylase levels monitoring of propofol-sedated patients is warranted.     

Basics in microbiology for the patient requiring intensive care

The major aim of the article is to clearly define the basic concepts of carriage, colonization and infection. The individuals defence system consisting of three potent lines of defence against carriage, colonization and infection is described in detail. Surveillance samples of throat and rectum are required to measure carriage defence and are distinguished from diagnostic samples including lower airway secretions and blood for the evaluation of the quality of the last two defence barriers against colonization and infection.Microbes and infections are classified using the concept of the carrier state. Low level pathogens are distinguished from high level pathogens and potentially pathogenic microorganisms. Low level pathogens including viridans streptococci, enterococci and coagulase negative staphylococci only cause morbidity. High level pathogens including Salmonella and potential pathogens such as Streptococcus pneumoniae, Staphylococcus aureus, Klebsiella, Acinetobacter baumannii and Pseudomonas aeruginosa causing pneumonia and/or septicaemia, cause attributable mortality. The concept of the carrier state allows the distinction of primary endogenous from secondary endogenous and exogenous infections. Seven recent studies demonstrate that the major infection problem is primary endogenous due to potential pathogens imported into the unit, varying between 50% and 75% in adult and paediatric units respectively. Nosocomial infections due to intensive care unit (ICU) microbes only include secondary endogenous and exogenous infections. Infection control targets the three types of infection mainly due to potential pathogens. To control primary endogenous infections parenteral antibiotics are administered immediately on admission. Eradication of digestive tract overgrowth by abnormal flora using enteral non-absorbable antibiotics controls secondary endogenous infections besides restoring systemic immunity. A high level of hygiene is required to prevent exogenous infection. Surveillance cultures are indispensable for the evaluation of the efficacy and compliance of this protocol, termed selective decontamination of the digestive tract (SDD) which has been shown to reduce morbidity and mortality by 65% and 20%, respectively.     

Evaluation of sinusitis in the intensive care unit patient.

OBJECTIVE: The purposes of this study were to evaluate the effectiveness of radiologic studies in diagnosing sinusitis in the intensive care unit (ICU) patient and to compare it with the effectiveness of endoscopic examination of the middle meatus. METHODS: We conducted a prospective collection of data in 141 ICU patients consulted for sinusitis over a 5-year period beginning in the 1994. RESULTS: Antral lavage was performed at least unilaterally in 112 patients, with a total of 195 lavages performed. Plain films and computer tomography scans predicted purulence in 41% (chi(2) = 2.9, P = 0.09) and 47% (chi(2) = 2.2, P = 0.14) of the cases, respectively, whereas the presence of purulence in the middle meatus as seen on endoscopy predicted purulence in the maxillary sinus in 78% of the lavages (chi(2) = 28.9, P = 8 x 10(-8)). When there was no evidence of purulence in the middle meatus on endoscopy, 73% of the lavages were negative. CONCLUSION: The most important predictor of a positive antral lavage in the ICU patient with suspected sinusitis is evidence of purulence on endoscopic examination of the middle meatus.     

Preparation of the intensive care patient for major surgery

Improved methods for monitoring and treating critically ill patients have increased the number of surgical candidates with multiorgan system impairment. Whereas such patients may have been considered too sick to undergo surgery in the past, many such patients linger in the intensive care unit unless definitive therapy is accomplished. Specific attention to review of the patient's preoperative preparation for surgery on a system-by-system basis may improve outcome substantially. The need for possible mechanical ventilation prior to transport to the operating room must receive particular attention. Pneumothorax, if present, must be treated prior to institution of positive-pressure ventilation so progression to tension pneumothorax can be avoided. Deficits in the circulating blood volume must be identified and corrected preoperatively if possible. A need for enhancement of cardiac output or alteration of vascular tone requires pulmonary arterial catheterization and indicates an increased operative risk. Metabolic abnormalities such as disturbances of acid-base balance, sodium or potassium concentration, and endocrinopathies are identified and corrected as much as possible prior to operation. Antibiotics are instituted as appropriate. Replacement of the red blood cell mass is dictated primarily by anticipated or actual blood loss. Factors of coagulation are infused on a replacement basis as necessary. Great care must be taken during transport to the operating room, as maintenance of intravascular monitoring devices, therapeutic infusions, and mechanical ventilation must continue during transport. Precautions must be taken to avoid hypothermia during transport and institution of anesthesia. Critical illness mandates specific considerations of the anesthetic agents to be utilized.

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Resumen Los métodos avanzados de monitoría y tratamiento de pacientes en estado crítico han resultado en un incremento en el número de candidatos a cirugía con alteraciones orgánicas multisistémicas. En tanto que tales pacientes puedan ser considerados como demasiado enfermos para ser sometidos a cirugía, muchos de ellos pueden quedar confinados por largos periodos a menos que se emprenda una terapia quirúrgica definitiva. El cuidado especial hacia revisar la preparación preoperatoria con bases en el análisis sitema-por-sistema puede mejorar sustancialmente el resultado final. Especial atención se debe prestar a la necesidad de posible ventilación mecánica con anterioridad al transporte a la sala de cirugía; si existe neumotórax, éste debe ser tratado antes de instaurar ventilación de presión positiva, con el objeto de evitar que progrese a un neumotórax a tensión. Los déficits en el volumen circulatorio deben ser identificados con certeza y, en lo posible, ser corregidos preoperatoriamente. La necesidad de mejorar el débito cardiaco o de alterar el tono vascular exige la cateterización arterial pulmonar y es indicativa de mayor riesgo operatorio. Las alteraciones metabólicas tales como desequilibrio ácidobase o en la concentración del sodio y del potasio, así como la presencia de endocrinopatías, deben ser identificadas y corregidas tanto como sea factible con anterioridad a la operación. Se deben administrar antibióticos en forma apropiada. El reemplazo de la masa corpuscular roja esta primordialmente indicado por las pérdidas de sangre previsibles o reales. Los factores de coagulación son infundidos según necesidad. Gran cuidado debe prestarse al transporte a la sala de cirugía, por cuanto el mantenimiento de los sistemas de monitoría intravascular, de las infusiones terapéuticas y de la ventilación mecánica es essencial en el curso del transporte. Se deben tomar precausiones para evitar la hipotermia durante el tranporte y durante la inducción de la anestesia. El estado crítico exige consideraciones específicas en cuanto a los agentes anestésicos que deban ser usados.

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Résumé L'amélioration des méthodes de surveillance et de prise en charge des patients de réanimation fait que l'on est de plus en plus souvent amené à opérer des patients dont plusieurs fonctions vitales sont gravement perturbées. Beaucoup de ces patients, qui autrefois auraient été jugés inopérables, vont rester en unité de soins intensifs à moins qu'un traitement définitif ne soit réalisé. L'étude pré-opératoire de ces patients organe par organe permet le plus souvent d'améliorer de façon importante les suites opératoires. La nécessité d'une éventuelle ventilation artificielle pré-opératoire doit notamment être envisagée. Un pneumothorax devra être drainer avant de débuter une ventilation en pression positive afin d'éviter la survenue d'un pneumothorax suffocant. Une hypovolémie doit être évaluée précisément et corrigée dans la mesure du possible avant l'intervention. La nécessité d'améliorer le débit cardiaque ou des modifications des résistances vasculaires périphériques témoignent d'un risque opératoire accru et nécessitent la prise de la pression artérielle pulmonaire. Des perturbations métaboliques telles qu'un déséquilibre acido-basique, ou des modifications de la kaliémie ou de la natrémie de même que des perturbations endocriniennes doivent être reconnues et corrigées autant que possible avant l'intervention. Une antibiothérapie est débutée lorsqu'elle est indiquée. Les transfusions de culots globulaires sont indiquées en fonction des pertes sanguines escomptées ou en cours. Des facteurs de coagulation sont administrés pour corriger des déficits lorsque cela est nécessaire. De grande précautions doivent être prises durant le transport en salle d'opération pour ne pas arracher les cathéters de mesure de pressions centrales et les cathéters de perfusions, la ventilation artificielle doit être maintenue pendant le transport. Des précautions doivent être prises pour éviter un refroidissement durant le transport et au moment de l'induction anesthésique. Les drogues anesthésiques utilisées seront sélectionnées en fonction de l'état du patient.