Renal failure in the respiratory intensive care unit

Aetiology and Short-Term Outcome of Acute Respiratory Distress Syndrome: A Real-World Experience from a Medical Intensive Care Unit in Southern India

Background

Acute respiratory distress syndrome (ARDS) is a highly fatal syndrome especially in resource constrained settings. In this study we prospectively studied the aetiology of ARDS and its short-term outcome.

Methods

Consecutive adults with suspected ARDS were screened. ARDS was diagnosed by the Berlin criteria. Aetiology was determined clinically, and by imaging and microbiological investigations. Patients presenting with fever, prominent cough and expectoration had a throat swab tested for influenza H1N1 virus. Outcome was discharge from hospital or death.

Results

A total of 42 patients, mean age 42.6 years, were studied. All received mechanical ventilation. Thirteen (31%) had pulmonary ARDS: H1N1 virus infection (n = 5), pneumonia (n = 7) and tuberculosis (n = 1). Twenty nine (69%) had extrapulmonary ARDS: sepsis (n = 16) and scrub typhus (n = 8). Thirty three (79%) died, of the nine survivors scrub typhus was diagnosed in seven patients.

Conclusion

The aetiology of ARDS in tropical medical setting is infection related. ARDS due to scrub typhus appeared to be mild with good outcome.

Etiology and Outcomes of ARDS in a Resource Limited Urban Tropical Setting

BACKGROUND

Several studies have been published in the western literature on the incidence, clinical course and outcome of patients with ARDS. However, there is limited data about ARDS in the tropics and moreover, the etiology and outcomes of ARDS in tropical countries are different from those of western nations. In tropical countries like India, resources are limited and costs of therapy play a major role in deciding treatment options. This prospective observational study was designed to analyze the clinical profile, outcomes and predictors of mortality of patients with ARDS in an urban tropical setting.

METHODS

75 patients ≥13 years, admitted in the medical intensive care unit of a teaching hospital in Kerala, India between March 2013 and February 2014, satisfying Berlin definition for ARDS were enrolled in the study. Lung protective ventilation strategy as laid by ARDS Network protocol was followed for every patient on mechanical ventilation. Due to scarcity of ventilators in our institution, invasive ventilation could not be provided for all ARDS patients. The criteria used for patient selection for non-invasive ventilation were hemodynamic stability, well compliant to the use of NIV mask and PaO2/FiO2 ratio >180 at the time of admission.

RESULTS

Out of the 75 patients, 51% were females and the mean age of the study population was 39.8 ± 3.3 years. Common aetiologies were leptospirosis (18.7%), bronchopneumonia (17.3%), scrub typhus and dengue (12% each). Lung injury score and sequential organ failure assessment score scores had statistically significant association with the severity of ARDS. Forty patients (53.3%) received invasive mechanical ventilation and 35 patients were managed with non-invasive ventilation at the time of admission. The mortality in our study was 45%. Altered sensorium (p-0.002), central cyanosis (p-0.024), elevated creatinine (p-0.036), acidosis (p < 0.001), hypotension (p < 0.001), multiorgan dysfunction (p-0.017), PEEP >12 cm H2O (p-0.036), days on ventilator <7 (p-0.014), PaO2/FiO2 Ratio <100 (p < 0.001), LIS>2.5 (p < 0.001) and SOFA score>11 (p < 0.001) were individual predictors of mortality.

CONCLUSION

Tropical infections form a major etiological component of ARDS in a developing country like India. More studies are required for determining criteria for using NIV in mild ARDS patients which would be helpful in resource limited countries. Timely administration of effective antimicrobial therapy in patients in the rural tropics may help to reduce mortality and financial burden due to ARDS.

Drug Dosing in Critically Ill Patients with Renal Failure: A Pharmacokinetic Approach

Accurate pharmacotherapy management in the intensive care unit (ICU) patient is crucial to minimize adverse drug events. Pharmacokinetic principles including absorption, distribution, metabolism, and excretion (ADME) all play an important role in determining the fate of medications used in the critical care setting. Renal failure in this setting further alters pharmacokinetic parameters, resulting in drug dosing changes. This article highlights and applies principles of drug dosing in normal patients and in the pharmacokinetically challenging environment of critically ill patients with renal failure. Specific drug dosing tables serve as a guide for the clinician to renally adjust medication doses in the critically ill patient with renal failure.

Acute Renal Failure in Critically Ill Patients

Acute renal failure is an important cause of morbidity in critically ill patients. Acute renal failure results from pre renal and postrenal causes and, most importantly, acute tubular necrosis (ATN). Although it is known that renal toxins and renal ischemia are the most common causes of ATN in hospitalized patients, the exact pathogenesis of this entity is still not fully understood. Patients in the intensive care unit are at high risk for ATN because of hemodynamic instability, the administration of neph rotoxic antibiotics or chemotherapeutic agents, and ex posure to radiographic contrast agents. The acquired immunodeficiency syndrome is also associated with an increased risk of renal failure development, either from complications of the disease itself or from its treatment. Many consequences of acute renal failure such as vol ume overload, acidosis, hyperkalemia, and serositis can be managed adequately with peritoneal dialysis, hemo dialysis, or a newer technique, continuous arteriove nous hemofiltration. Despite improvements in treat ment, however, the mortality of ATN remains high. In this review, we recommend measures to prevent ATN in certain clinical situations that commonly occur among critically ill patients. We also review therapeutic options for treating patients in whom acute renal failure devel ops and discuss newer developments that may begin to reduce the excessive morbidity associated with ATN.

Comparison between early and delayed acute kidney injury secondary to infectious disease in the intensive care unit

BACKGROUND

Results from a number of studies suggest that the delayed manifestation of acute kidney injury (AKI) is associated with higher in-hospital mortality, while other studies were unable to demonstrate any difference among early and delayed AKI in terms of in-hospital mortality.

OBJECTIVE

The aim of this study was to investigate differences in outcome among patients with AKI upon admission to an intensive care unit (ICU) and those who develop AKI post-admission.

METHODS

We studied patients with AKI secondary to infectious diseases admitted to the ICU. We retrospectively compared data on patients admitted with AKI (early AKI) with data on those who developed AKI 24 h after admission (delayed AKI).

RESULTS

Acute kidney injury occurred in 147 of 829 (17.7%) patients admitted to the ICU. Of these, 96 (65%) had early AKI and 51 (35%) had delayed AKI. Renal failure was classified according to RIFLE criteria-an AKI-specific severity score that is used to place patients into one of five categories: risk, injury, failure, loss or end-stage renal disease. Based on these criteria, 6% of the early AKI and 4% of the delayed AKI patients were in risk category, 18% of the early AKI and 27% of the delayed AKI patients were in the injury category and 76% of the early AKI and 69% of the delayed AKI patients were in the failure category. We found no significant association between RIFLE and death. On admission, patients with early AKI had statistically significantly higher serum urea and creatinine levels than delayed AKI patients (P<0.0001). Arterial bicarbonate was lower in early AKI (P=0.02). Sepsis, hypotension and use of mechanical ventilation were more frequent in delayed AKI (P<0.05). The APACHE II score was higher in early AKI (P=0.05) patients. In total, 98 (66.7%) patients died, with a tendency towards higher mortality in patients with delayed AKI (61.5 vs. 76.5%, P=0.07).

CONCLUSION

Mortality among patients with infectious diseases-associated AKI admitted to the ICU is high, with a trend to be higher in those who developed delayed AKI.

Incidence and risk factors for the development of acute renal failure in patients with ventilator-associated pneumonia

AIM

Infections are one of the most important risk factors for the development of acute renal failure (ARF) and ventilator-associated pneumonia (VAP) has been reported as one of the most frequent infection in intensive care units (ICU). Sepsis, shock, multiorgan dysfunction syndrome (MODS), use of nephrotoxic antibiotics and mechanical ventilation are potential risk factors for development of ARF during VAP. The objective of the study was to evaluate the incidence of ARF in patients with VAP and the role of VAP-related potential risk factors in the development of ARF.

METHODS

One hundred and eight patients who were admitted to the pulmonary ICU of a university hospital and developed VAP were included in this prospective observational cohort study. Only first episodes of VAP were studied. Diagnosis was based on microbiologically confirmed clinical findings. Potential outcome variables including responsible pathogens, recurrence, polymicrobial aetiology, bacteraemia, multidrug resistance of microorganisms, late/early VAP and sepsis and other known risk factors for development of ARF were evaluated. Risk factors were analysed by logistic regression analysis for significance.

RESULTS

Incidence of ARF was 38% (n = 41). Pneumonia with multidrug resistant pathogens (odds ratio, (OR) 5; 95% confidence interval (95%CI), 1.5-18; P = 0.011), sepsis (OR, 5.6; 95%CI, 1.7-18; P = 0.005) and severity of admission disease (Acute Physiology and Chronic Health Evaluation II score: OR, 1.1; 95%CI, 1.02-1.3; P = 0.017) were independent risk factors for the development of ARF during VAP episodes in multivariate analysis.

CONCLUSION

These results showed that the incidence of ARF is high during the VAP episodes and that VAP developed with multidrug resistant pathogens and sepsis have an independent effect on the development of ARF.

Incidence, risk factors and prognostic factors of acute renal failure in patients admitted to an intensive care unit

The objective of the present study was to assess the incidence, risk factors and outcome of patients who develop acute renal failure (ARF) in intensive care units. In this prospective observational study, 221 patients with a 48-h minimum stay, 18-year-old minimum age and absence of overt acute or chronic renal failure were included. Exclusion criteria were organ donors and renal transplantation patients. ARF was defined as a creatinine level above 1.5 mg/dL. Statistics were performed using Pearsons' chi2 test, Student t-test, and Wilcoxon test. Multivariate analysis was run using all variables with P < 0.1 in the univariate analysis. ARF developed in 19.0% of the patients, with 76.19% resulting in death. Main risk factors (univariate analysis) were: higher intra-operative hydration and bleeding, higher death risk by APACHE II score, logist organ dysfunction system on the first day, mechanical ventilation, shock due to systemic inflammatory response syndrome (SIRS)/sepsis, noradrenaline use, and plasma creatinine and urea levels on admission. Heart rate on admission (OR = 1.023 (1.002-1.044)), male gender (OR = 4.275 (1.340-13642)), shock due to SIRS/sepsis (OR = 8.590 (2.710-27.229)), higher intra-operative hydration (OR = 1.002 (1.000-1004)), and plasma urea on admission (OR = 1.012 (0.980-1044)) remained significant (multivariate analysis). The mortality risk factors (univariate analysis) were shock due to SIRS/sepsis, mechanical ventilation, blood stream infection, potassium and bicarbonate levels. Only potassium levels remained significant (P = 0.037). In conclusion, ARF has a high incidence, morbidity and mortality when it occurs in intensive care unit. There is a very close association with hemodynamic status and multiple organ dysfunction.

Has mortality from acute renal failure decreased? A systematic review of the literature

PURPOSE

To determine mortality rates in patients with acute renal failure during the past decades.

METHODS

We performed a MEDLINE search using the keywords "acute renal failure" crossed with "outcome," "mortality," "ICU," "critically ill" or "prognosis" in the period from January 1970 to December 2004. Abstracts and full articles were eligible if mortality rates were reported. We also reviewed the bibliographies of available studies for further potentially eligible studies. The dates of the observation period for each study and not the publication dates were considered for the analysis, so the earliest data were from 1956.

RESULTS

Of 85 articles fulfilling the criteria, 5 were excluded because of duplicate publications using the same database, so that 80 were included in our review with a total of 15897 patients. Mortality rates in most studies exceeded 30%, and there was no consistent change over time.

CONCLUSION

Despite technical progress in the management of acute renal failure over the last 50 years, mortality rates seem to have remained unchanged at around 50%.

Drug-Induced Renal Failure in the ICU

Drug-induced renal failure is a frequent complication in the setting of ICU. Generally spoken pathomechanisms leading to drug-induced renal failure can be divided into hemodynamic effects, epithelial toxicity or crystalline nephropathy. The risk of drug-induced renal failure is increased by any form of hypovolemia (i.e. true hypovolemia or reduced effective circulating volume), older age, pre-existent renal impairment, and concomitant application of two or more nephrotoxins. This article reviews drugs most frequently responsible for renal failure in the ICU and discusses preventive measures. (Int J Artif Organs 2004; 27: 1034-42)

Acute renal failure in medical and surgical intensive care units--a one year prospective study

The spectrum of acute renal failure is different in intensive care unit (ICU) vs. non-ICU population. This one year prospective study carried out in medical and surgical intensive care units showed an incidence of 8.6% of acute renal failure. The incidence of acute renal failure was highest in medical ICU (17.2%) followed by burns ICU (5.3%), pulmonary ICU (5.2%), stroke ICU (4.4%), surgical ICU (3.1%) and least in coronary ICU (1.3%). The acute renal failure was attributable to medical causes in 68% followed by surgery and trauma in 21.2%, burns in 5.6% and pregnancy related in 5.1%. In majority, acute renal failure was multifactorial. Septicemia was the commonest cause in both medical (50%) and surgical (86%) ICUs. Multi organ system failure was present in 77.3% of patients with acute renal failure. Approximately 40% required dialysis. The mortality of acute renal failure was 62% and the mortality was correlated with the number of organ system failures, presence of oliguria and septicemia. The mean ICU stay was significantly shorter in the non-survivors.

Renal failure in the ICU: comparison of the impact of acute renal failure and end-stage renal disease on ICU outcomes

BACKGROUND

Acute renal failure (ARF) is associated with a persistent high mortality in critically ill patients in intensive care units (ICUs). Most studies to date have focused on patients with established, intrinsic ARF or relatively severe ARF due to multiple factors. None have examined outcomes of dialysis-dependent chronic renal failure [end-stage renal disease (ESRD)] patients in the ICU. We examined the incidence and outcomes of ARF in the ICU using a standard definition and compared these to outcomes of ICU patients with either ESRD or no renal failure. We sought to determine the impact of renal dysfunction and/or loss of organ function on outcome.

METHODS

We prospectively scored 1530 admissions to eight ICUs over a 10-month period for illness severity at ICU admission using the Acute Physiological and Chronic Health Evaluation (APACHE III) evaluation tool. Patients were defined as having ARF based on the definition of Hou et al (Am J Med 74:243-248,1983) designed to detect significant measurable declines in renal function based on serum creatinine. ESRD patients were identified as being chronically dialysis-dependent prior to ICU admission and the remainder had no renal failure. Clinical characteristics at ICU admission and ICU and hospital outcomes were compared between the three groups.

RESULTS

We identified 254 cases of ARF, 57 cases of ESRD and 1219 cases of no renal failure for an incidence of ARF of 17%. Roughly half the ARF patients had ARF at ICU admission and the remainder developed ARF during their ICU stay. Only 11% of ARF patients required dialysis support. ARF patients had significantly higher acute illness severity scores than those with no renal failure, whereas patients with ESRD had intermediate severity scores. ICU mortality was 23% for patients with ARF, 11% for those with ESRD, and 5% for those with no renal failure. There was no difference in outcome between patients who had ARF at ICU admission and those who developed ARF in the ICU. Patients with ARF severe enough to require dialysis had a mortality of 57%. APACHE III predicted outcome very well in patients with no renal failure and patients with ARF at the time of scoring but underpredicted mortality in those who developed ARF after ICU admission and overestimated mortality in patients with ESRD.

CONCLUSIONS

ARF is common in ICU patients and has a persistent negative impact on outcomes, although the majority of ARF is not severe enough to require dialysis support. The mortality of patients with ARF from all causes is almost exactly similar to that noted using the same criteria two decades ago. More profound ARF requiring dialysis continues to have an even greater mortality. Nevertheless, acute declines in renal function are associated with a mortality that is not well explained simply by loss of organ function. The majority of ARF patients who did not require dialysis still had a considerably higher mortality than the ESRD patients, all of whom required dialysis; while ARF patients who did require dialysis had a much higher morality than ESRD patients. APACHE III performs well and captures the mortality of patients with ARF at the time of scoring. Development of ARF after scoring has a profound effect on standardized mortality. We were unable to identify a unique mortality associated with ARF, but the presence of measurable renal insufficiency continues to be a sensitive marker for poor outcome.

Acute renal failure and dialysis in the chronically critically ill patient

Acute renal failure is a common clinical problem in the intensive care unit (ICU) and is associated with significant morbidity and mortality. There is no "magic bullet" to prevent acute renal failure or to modify the clinical course of established renal failure. The approach to therapy is directed to the early initiation of dialysis therapy. Continuous dialysis therapy is becoming the preferred form of dialysis in the ICU.

Acute renal failure in the cardiac care unit: etiologies, outcomes, and prognostic factors

BACKGROUND

Heart disease is a leading cause of hospitalizations, and its prevalence is expected to grow rapidly over the next few decades. The purpose of this study was to examine the incidence, etiologies, outcomes, and risk factors for mortality of acute renal failure (ARF) in cardiac care unit (CCU) patients.

METHODS

A retrospective, cohort study examining all patients who developed ARF while in the CCU at Barnes-Jewish Hospital over a 17-month time period was performed. Charts were reviewed to determine etiologies, hospital mortality rates, and risk factors for mortality.

RESULTS

Four percent of admissions to the CCU met criteria for ARF while in the unit. The etiologies of ARF were congestive heart failure (CHF; 35%), multifactorial (usually involving CHF; 26%), arrest/arrhythmia (13%), contrast (11%), volume depletion (6%), sepsis (6%) and obstruction (3%). The mortality rate was 50%. Oliguria, mechanical ventilation, and decreased cardiac function were statistically significant risk factors for mortality by univariate but not multivariate analysis. Thirty percent of patients with a cardiac index of less than 2.0 liter/min/m2 survived to discharge.

CONCLUSIONS

ARF occurs commonly in CCU patients and is associated with a high mortality rate. However, there are a significant number of survivors even among patients with severely depressed cardiac function.

Transcutaneous renal function monitor: precision during unsteady hemodynamics

OBJECTIVE

Hospital acquired renal dysfunction, most commonly caused by renal hypoperfusion, dramatically increases mortality in intensive care patients. Glomerular filtration rate (GFR) is rapidly altered during renal hypoperfusion, and a more rapid means of GFR measurement may prompt institution of renal-specific therapy. We hypothesized that a transcutaneous renal function monitor can rapidly and accurately assess acute changes in GFR within a time frame much shorter than the 2-4 hours currently available.

METHODS

The study design was a prospective determination of the capability to measure GFR transcutaneously. In three different studies, concurrent transcutaneous measurement of GFR, using the rate of disappearance of 99mTc-diethylenetriaminepentaacetic acid (DTPA), was compared by correlation and standard deviation (SD) to reference standards of DTPA plasma clearance, serum inulin clearance, or serum creatinine.

RESULTS

Continuous transcutaneous clearance (TC) measurement correlated with standard DTPA plasma clearance techniques (r = 0.93). Acute pharmacologically induced changes in GFR are detectable by TC measurement within 12-20 min, a time interval significantly affected by the data acquisition interval. Excess patient movement in the ICU patients created clearance artifacts in 50% of clearance traces. Retrospective analysis of ICU patient data reveal TC measurements are 93% specific and 92% sensitive for serum creatinine levels in critically ill patients.

CONCLUSIONS

TC monitoring provides prompt indication of directional changes in GFR and may provide the clinician warning of inadequate resuscitation. Prospective analysis of the specificity, sensitivity, and TC guided renal-specific resuscitation is needed.

Renal involvement in the systemic inflammatory reaction syndrome

Uncontrolled infection quite often leads to systemic inflammatory reaction syndrome (SIRS) and multiorgan dysfunction (MOD) syndrome. Thirty-five consecutive patients (19 males) fulfilling strict diagnostic criteria for SIRS were enrolled in two multicenter prospective double-blind trials involving new therapies for SIRS. The patients were followed prospectively up to day 28 after the enrollment. In the 35 patients with SIRS, males predominated in the age group below 40 (10/12, 83%) compared to the older group (nine males out of 23, 39%). Out of 16 females presenting with SIRS, only two were below the age of 40. This distribution was statistically different than our general MICU population. The serum albumin in these patients was uniformly low, with a mean of 22.5 gm/L. The bulk of SIRS patients (22/35; 63%) went on to develop acute renal failure (ARF). Although statistically not different, skin and peritoneal infections were more common in ARF group while pulmonary infections in non-ARF group. The majority of blood-cultures grew gram-positive organisms. Resolution of SIRS occurred within first 3 days in greater number of non-ARF survivors than ARF survivors (6/9, 66.7% vs. 6/16, 37.5%). Of the 22 ARF patients, 17 showed improvement in their renal function; the five who did not, died before day 28. The overall mortality (about 32%) was similar in both groups. Patients who developed both ARF and ARDS did not survive. In conclusion. SIRS occurs mostly in elderly patients, almost always in patients with low albumin levels. Premenopausal women seem to be protected. Blood cultures isolated a gram-positive organism in the majority of cases. Improvement in serum creatinine suggests good prognosis. The mortality in ARF and non-ARF groups is similar.

Impact of renal dysfunction on weaning from prolonged mechanical ventilation

BACKGROUND: In the intensive care unit (ICU) setting, the combination of mechanical ventilation and renal replacement therapy (RRT) has been associated with prolonged length of hospital stay, high cost of care and poor outcome. We gathered outcome data on patients who had severe renal dysfunction on transfer to our regional weaning center (RWC) for attempted weaning from prolonged mechanical ventilation (PMV). We screened the admission laboratory values of 1077 patients transferred to our RWC over an 8-year period. We reviewed the medical records of patients with serum creatinine > 2.5 mg/dl. RESULTS: Sixty-three patients met screening criteria and 40 patients were on RRT at the time of transfer. Eighteen patients had begun chronic RRT at least 2 months prior to admission to the transferring hospital for their current illness. Twenty-two patients had RRT initiated at the transferring hospital. Ten patients had RRT initiated at the RWC; eight patients had improvement or resolution of azotemia at our facility. RRT was withheld at patient/family request in five patients with progressive renal failure. None of the 50 patients who received RRT recovered renal function during treatment at our RWC. Intermittent hemodialysis was the standard RRT at the RWC. Duration of mechanical ventilation prior to transfer to the RWC was 49.7 +/- 33.5 days (mean +/- SD).Outcome of weaning attempts in the 63 patients was as follows: 13% weaned, 3% failed to wean and 84% died. These outcomes were significantly worse (P<0.001) than those in the 1014 patients whose admission serum creatinine was </= 2.5 mg/dl (58% weaned, 15% failed to wean, 27% died). The five patients in whom RRT was withheld were predominantly in progressive multisystem organ failure, and were unlikely to have survived regardless of RRT. From the study cohort, only one of the 10 patients discharged alive returned home, in contrast to 42% of the control group. No patient with severe renal dysfunction survived to 1 year post-discharge, compared to a 1-year survival of 38% in the control group (P = 0.029). Only four of the 10 patients survived more than 1 month, with the longest survival being 122 days. CONCLUSIONS: Patients who require PMV and RRT have a very poor prognosis. The small number of patients with renal insufficiency not requiring RRT had a more favorable hospital outcome and mortality, but long-term survival remained poor.

Risk Factors to Predict Renal Failure and Death in the Medical Intensive Care Unit

The ability to predict outcomes based on admission criteria has important implications, both prognostically and for assessing interventions on comparable groups. Use of severity of disease scoring systems such as the APACHE II score for predicting mortality has become widespread. There is no comparable formula for acute renal failure. We prospectively evaluated 115 consecutive admissions to the medical intensive care unit to define risk for renal failure from admission data and to assess the impact of admission hypoalbuminemia levels on outcome. Diagnosis, age, serum creatinine and albumin levels, urinary electrolyte concentrations and osmolality, daily serum creatinine levels, and urine output were recorded. Admission APACHE II score was calculated. Admission hypoalbuminemia (57% of patients) was associated with both acute renal failure and death (odds ratios, 16.19 and 8.06, respectively). The Glasgow coma score distinguished between patients in whom acute renal failure developed and in those it did not. Low urine osmolality (<400 mOsm/kg) was the most significant factor in predicting mortality (odds ratio, 9.87). Mortality was lowest in the normal albumin group (2%), intermediate in the low albumin/no renal failure group (12%), and highest in the low albumin/acute renal failure group (53%). The APACHE II score was accurate in 3 of 14 deaths in the hypoalbuminemic population and in the one normal albumin patient who died. We conclude that at admission, hypoalbuminemia, urinary hypo-osmolality, and abnormal creatinine levels are predictive of acute renal failure and death, diagnosis, and mental status impact on the risk for acute renal failure. APACHE II lacks predictive value in hypoalbuminemic patients.

Polyethylene glycol nephrotoxicity secondary to prolonged high-dose intravenous lorazepam

OBJECTIVE

To report a patient with a probable acute tubular necrosis (ATN) induced by chronic exposure to polyethylene glycol (PEG)-400 via long-term, massive dosage of intravenous lorazepam.

CASE SUMMARY

A 57-year-old man with a history of alcohol abuse was admitted to the intensive care unit for acute respiratory failure. Lorazepam therapy was initiated in anticipation of alcohol withdrawal. Dosages up to 18 mg/h were required to provide adequate sedation and optimize ventilation. On day 43, the patient developed oliguric ATN of unknown etiology. The cumulative intravenous lorazepam dose was 4089 mg, equivalent to approximately 220 mL of PEG-400. Blood urea nitrogen concentrations followed a pattern that paralleled lorazepam dosage increases and decreases. Protein and granular casts were evident in urinalyses performed on days 12 and 29. The patient eventually experienced complete recovery.

DISCUSSION

ATN associated with intravenous PEG was last reported in 1959 in 6 of 32 patients receiving a cumulative PEG-300 dose of 120-200 mL over 3-5 days via an intravenous nitrofurantoin preparation. Two of the 6 patients died. Chronic administration of intravenous PEG to rabbits over a 5-week period has caused cloudy swelling of the renal tubular epithelium, increased blood urea concentrations, and death in some animals.

CONCLUSIONS

ATN probably resulted from chronic PEG exposure via massive doses of lorazepam injection, possibly enhanced by concurrent administration of vancomycin.

Mild renal ischemia activates primed neutrophils to cause acute renal failure

The role of neutrophils (PMN) in acute renal failure (ARF) is controversial. Although the development of acute renal failure (ARF) frequently occurs in situations where there is partial activation of PMN (primed PMN) and mild renal ischemia, the interaction between primed PMN and ischemic organs has not been studied in any biological system. To define the interaction between primed PMN and mild renal ischemia, kidneys were made ischemic for 10 minutes in situ and reperfused by the isolated kidney technique with untreated PMN or PMN primed with low concentrations of lipopolysaccharide (LPS) or phorbol myristate acetate (PMA). We found that primed PMN had no effect on control (non-ischemic) kidneys and that untreated PMN did not cause injury to kidneys previously subjected to mild ischemia. However, addition of primed PMN to mildly ischemic kidneys caused severe injury. To determine the nature of renal injury, ischemic kidneys were reperfused with primed PMN and catalase (CAT) or the elastase inhibitor, Eglin C. In ischemic kidneys reperfused with LPS-primed PMN, Eglin C (but not CAT) was partially protective while in ischemic kidneys reperfused with PMA-primed PMN, CAT (but not Eglin C) was partially protective. Reperfusion with both CAT and Eglin C completely prevented the damaging effects of either LPS- or PMA-primed PMN. In conclusion, addition of primed but not untreated PMN causes ARF in mildly ischemic kidneys by PMN oxidant- and/or protease-mediated mechanisms. This synergism could account for the high frequency of ARF in conditions associated with prerenal azotemia and primed PMN.

Comparison of pump-driven and spontaneous continuous haemofiltration in postoperative acute renal failure

In a comparison of spontaneous continuous arteriovenous haemofiltration (CAVH) and pump-driven haemofiltration (PDHF) for acute renal failure after surgery, 116 patients admitted to a surgical intensive care unit were assigned CAVH (48) or PDHF (68). The method of assignment was that a patient was treated by PDHF if he or she was the only patient requiring treatment at that time (only one pump was available); any other patient coming to the unit would be treated by CAVH. The groups were slightly unbalanced because there were fewer simultaneous cases than expected. The main endpoints were survival rate, control of uraemia, and additional application of haemodialysis. There were no differences between the patient groups in age, duration of treatment, severity of illness, serum creatinine concentration at the start of treatment, or cause of acute renal failure. Both treatments adequately controlled uraemia and fluid overload. However, the survival rate was significantly higher with PDHF than with CAVH (6 [12.5%] vs 20 [29.4%]; p less than 0.05). The daily ultrafiltrate volume was significantly higher with PDHF than with CAVH (15.7 [95% confidence interval 13.6-17.8] vs 7.0 [6.6-7.4] l/day; p less than 0.05). The volume of ultrafiltrate in patients with ischaemic or sepsis-induced acute renal failure was correlated with the survival rate. This finding suggests that the better survival rate in the PDHF group was due to faster elimination of toxic mediators (of molecular weight 800-1000 daltons) through the filter membrane by high-volume haemofiltration.

Effect of uremia and its treatment on pulmonary function

Alterations in respiratory drive, mechanics, muscle function, and gas exchange are frequent if not invariable consequences of uremia. Pulmonary dysfunction may be the direct result of circulating uremic toxins or may result indirectly from volume overload, anemia, immune suppression, extraosseous calcification, malnutrition, electrolyte disorders, and/or acidbase imbalances. The pulmonary system is unique because it is affected by the disease and its treatment. Acetate hemodialysis reduces alveolar ventilation and PaO2 due to extrapulmonic CO2 unloading. Peritoneal dialysis increases alveolar ventilation and intraperitoneal pressure. The latter leads to an elevated and lengthened diaphragm, a reduced functional residual capacity, basilar atelectasis, possible hypoxemia, and altered respiratory muscle function. In patients on chronic peritoneal dialysis, adaptations may occur that limit the reductions in lung volumes, PaO2, and respiratory muscle strength that are often observed during acute peritoneal dialysis. This review details how uremia and dialysis interact to alter pulmonary function.

Clearance of ceftriaxone in critical care patients with acute renal failure

Serum concentrations of ceftriaxone (RocephinTM), a third generation cephalosporin, were monitored in 5 operative intensive care patients suffering from acute renal failure (ARF) and compared to those of 7 patients without renal disturbance. For a period of 7 days, a fixed dose of 2 g/day was given by a 15 min infusion. Pharmacokinetic parameters were calculated by fitting all serum and urine data measured over the period of treatment. Ceftriaxone free fraction was measured on days 2 and 7. There was no evidence for an intraindividual change in ceftriaxone-clearance during the observation period. Ceftriaxone renal clearance was closely dependent on creatinine clearance according to a linear regression expressed by Clren = 0.14 Clcrea + 2.2 (r = 0.951, p less than 0.0001). Total clearance was also associated with creatinine clearance: Cltot = 0.19 Clcrea + 8.2 (r = 0.964, p less than 0.0001). Related to the free fraction, renal clearance was in the range of the glomerular filtration rate. Non-renal clearance was strongly decreased when related to the free fraction indicating that biliary excretion is also impaired in patients with acute renal failure. Obviously no compensatory increase in hepatic ceftriaxone clearance takes place. It is concluded that elimination of ceftriaxone may be strongly impaired during acute renal failure in surgical intensive care patients and that dosage should be restricted according to degree of the impairment of creatinine clearance.

An early test of survival in patients with the adult respiratory distress syndrome. The PaO2/FIo2 ratio and its differential response to conventional therapy. Prostaglandin E1 Study Group

Patients with established adult respiratory distress syndrome (ARDS) have a mortality rate that exceeds 50 percent. We analyzed the magnitude of hypoxemia as manifest by the PaO2/FIO2 ratio and its early response to conventional therapy including positive end-expiratory pressure (PEEP) in the placebo group of a large multicenter study. The PaO2/FIO2 ratio was not different at the time of diagnosis of ARDS in those patients who lived compared to those who subsequently died. After one day of conventional therapy including PEEP, those patients who survived increased their PaO2/FIO2 ratio. The nonsurvivors did not improve over a seven-day course. The difference in the PaO2/FIO2 ratio was significant throughout the seven-day observation period. We conclude that the early response to conventional therapy picks a patient population with a good prognosis and can be used as a test of likely survival from ARDS.

Neutrophil accumulation and structural changes in nonpulmonary organs after acute lung injury induced by phorbol myristate acetate

Multiple nonpulmonary organ failure contributes significantly to the high mortality rate associated with the adult respiratory distress syndrome (ARDS). However, little is known about specific structural and/or functional alterations that occur in nonpulmonary organs in this syndrome. Therefore, the present study was designed to test the hypothesis that inflammatory cell infiltration and structural changes occur both in the lungs and in nonpulmonary organs in ARDS. To test this hypothesis, neutrophil accumulation and structural alterations were evaluated in nonpulmonary organs from dogs with acute lung injury produced by intravenous phorbol myristate acetate (PMA) (30 micrograms/kg; n = 5). As expected, morphologic changes were present in the lungs of the PMA-treated animals and included a diffuse neutrophilic pneumonitis with interstitial, vascular, and alveolar components. PMA-treated dogs had significant increases in neutrophils (expressed as PMN/mm2 tissue section area) compared with those in control animals in the following organs: heart, 14 +/- 3 versus 4 +/- 1; brain, 2.5 +/- 0.3 versus 0.7 +/- 0.3; duodenum, 34 +/- 7 versus 10 +/- 2; liver, 397 +/- 16 versus 103 +/- 12 (p less than 0.025, all comparisons). In addition, severe necrosis and inflammation of vessels, sinusoidal thrombosis, and hepatic necrosis were noted in the liver. Like the changes noted in the lung, hepatic lesions appeared to be vascular in origin and were consistent with lesions produced by the intravascular activation of neutrophils. No microscopic lesions were detected in the brain, kidney, duodenum, and heart. Taken together, the finding of concurrent lung injury, liver injury, and nonpulmonary organ neutrophil accumulation suggests the possibility of a common pathway of injury in this model of ARDS.

Hepatic dysfunction in the adult respiratory distress syndrome

Multiple organ system failure is a major cause of mortality in the adult respiratory distress syndrome (ARDS). We serially evaluated parameters of multiple organ function in 24 patients during the first week after the diagnosis of ARDS and related them to outcome. The adult respiratory distress syndrome was associated with sepsis (n = 16), postoperation (n = 7), and trauma (n = 1). Fourteen of the 24 patients (58 percent) died. Although there were no significant differences in the indices of pulmonary or renal dysfunction between survivors and nonsurvivors, evidence of hepatic dysfunction was different in the two groups. On the day we identified ARDS, serum bilirubin was 1.2 mg/dl +/- 0.9 mg/dl in patients who survived, and was 2.3 mg/dl +/- 2.8 mg/dl (chi +/- SD) in those who died. Initial serum glutamic oxalacetic transaminase (SGOT) and alkaline phosphatase levels were lower in survivors than in those who died (71 +/- 44 IU/L vs 399 +/- 807 IU/L, and 121 +/- 53 IU/L vs 269 +/- 243 IU/L, respectively). These abnormalities persisted during the first week of respiratory failure, with significant differences in serum bilirubin and alkaline phosphatase between survivors and nonsurvivors (p less than 0.01). The degree of pulmonary and renal dysfunction was similar in both groups. These data suggest that liver function may be a major determinant of survival in patients with the adult respiratory distress syndrome.

Common complications in critically ill patients

Patients in intensive care units (ICUs) are subject to many complications connected with the advanced therapy required for their serious illnesses. Complications of ventilatory support include problems associated with short-term and long-term intubation, barotrauma, gastrointestinal tract bleeding, and weaning errors. Cardiac tachyarrhythmias can arise from a patient's intrinsic cardiac disease, as well as from drug therapy itself. Hemodynamic monitoring is crucial to careful patient management, but it is associated with technical complications during insertion such as pneumothorax, as well as interpretive errors such as those caused by positive end-inspiratory pressure. Acute renal failure can develop as a result both of therapy with drugs such as aminoglycosides and hypotension of many etiologies, as well as the use of contrast media. Nosocomial infection, which is a dreaded complication in ICU patients, usually arises from sources in the urinary tract, bloodstream, or lung. Complications frequently can arise if the interactions of drugs commonly used in the ICU are not recognized. Further, the ICU patient is subject to nutritional complications, acid base problems, and psychological disturbances. This monograph deals with the frequency, etiology, and prevention of these common ICU complications.

Improving the prognosis in acute renal and respiratory failure

We have achieved smooth homeostasis in patients with acute renal and respiratory failure by means of machine-controlled, continuous ultrafiltration and simultaneous bicarbonate hemodialysis with a polysulfone, biocompatible membrane (CUPID). No adverse effects were seen, even after 22 days of continued treatment. Mortality was reduced (7/14) when compared to that of a similar group given short conventional daily acetate hemodialysis and ultrafiltration with a cuprophane membrane (12/18).

Clinical outcome of respiratory failure in patients requiring prolonged (greater than 24 hours) mechanical ventilation

Patients requiring prolonged (greater than 24 hours) mechanical ventilation have various conditions that result in respiratory failure. All patients requiring prolonged mechanical ventilation were subdivided into the following six groups: uncomplicated acute lung injury; respiratory failure complicated by multisystem failure; previous lung disease; trauma; other medical causes; and routine postoperative ventilation. During a one-year period, 327 patients required prolonged mechanical ventilation; acute lung injury and chronic obstructive pulmonary disease were the predominant conditions. Sepsis was both the major predisposing factor for and complication of acute lung injury. Mortality for patients with acute lung injury was 40 percent in the uncomplicated group and 81 percent in patients with acute lung injury complicated by multisystem failure. Acute respiratory failure in association with acute renal failure had a mortality of 89 percent. Number of organ systems involved also correlated with mortality. In patients with chronic obstructive pulmonary disease and pneumonitis or retained secretions, mortality was lower (30 percent), but a significant percentage of these patients (43 percent) became ventilator-dependent. Ventilator dependence did not significantly increase mortality during the course of respiratory failure.

Complications of acute respiratory failure

Many complications can occur during the management of acute respiratory failure and may involve multiple organs. Some of these complications can be avoided by preventive measures. We find evaluation of serial chest roentgenograms extremely useful for the early detection of several complications (figure 4). In addition, prophylactic use of heparin to prevent pulmonary emboli, prophylactic antacid or cimetidine therapy to prevent gastric bleeding, careful monitoring of renal function, appropriate measures to reduce the incidence of colonization and nosocomial infection, and early recognition of nosocomial infections are some of the measures essential to increased survival of patients with acute respiratory failure.

Acute renal failure in an intensive care unit: incidence, prediction and outcome

A review of the case notes of 475 patients with no history of renal disorder admitted to an intensive care unit, showed that 23% (109) developed acute renal failure. This complication occurred more commonly in patients with major burns (75%), and following surgery to the abdominal aorta (38%), but less commonly after self-poisoning episodes (5%). Scores were provided from stepwise multiple regression analysis which were derived from the diagnostic group, the presence of sepsis, the presence of systolic hypotension and age, and correctly predicted development of acute renal failure in 79% of the cases studied. Attempted prophylaxis appears to have little effect on the incidence of acute renal failure whilst dialysis reduced the mortality from 95% to 72%. Use of the scoring system to allow earlier diagnosis and treatment of acute renal failure could reduce the present mortality by 43%.

Complications of acute respiratory failure

Acute respiratory failure is frequently fatal. Attempts to decrease mortality must include attention to pulmonary and extrapulmonary complications. Pulmonary complications include pulmonary emboli, barotrauma, fibrosis, and pneumonia. Swan-Ganz catheters, tracheal intubation, and mechanical ventilation can also result in pulmonary complications. Extra-pulmonary complications such as gastrointestinal hemorrhage, renal failure, infection, and thrombocytopenia may increase mortality. Early diagnosis, aggressive treatment, and prophylaxis of complications should increase survival.

Acute renal failure. Multivariate analysis of causes and risk factors

Accepted causes (acute insults) and risk factors for the development of acute renal failure were defined, quantitatively assessed, and tested for statistical significance in 143 patients with acute tubular necrosis. Sixty-two percent of patients had more than one acute insult, and 48 percent had more than one suspected risk factor. Hypotension, excessive aminoglycoside exposure, pigmenturia, and dehydration were identified as highly significant acute insults, while it was concluded that sepsis and administration of radiocontrast material could not be incriminated as causes of acute tubular necrosis. An additive interaction between acute insults was demonstrated, and the severity of acute renal failure was related to the number and severity of acute insults. Patients with oliguric renal failure had more severe acute insults than patients with nonoliguric renal failure. Preexisting renal disease and chronic hypertension were significant risk factors, the latter only when hypotension had been one of the acute insults. An age of more than 59 years, gout and/or chronic hyperuricemia, diabetes, and long-term diuretic administration were not found to be significant risk factors.

Metabolic disorders in severe abdominal sepsis: Glutamine deficiency in skeletal muscle

The metabolic profiles of 14 patients with prolonged abdominal sepsis were analysed on the second day after laparotomy. The profiles of survivors were compared with those of non-survivors who died one to five days after the time of evaluation due to uncontrollable multiple organ failure. In the non-surviving patients plasma glucose and glucagon levels were significantly higher than in surviving patients. The plasma concentrations of phosphoserine, cysteine, valine, phenylalanine, and 3-methylhistidine were found to be significantly increased in non-survivors and their muscle tissue showed significantly decreased concentrations of glutamine, proline and lysine with increases in valine and leucine. A correct classification of non-survivors and survivors could be obtained from the plasma and muscle amino acid concentrations, the highest discriminant power being from muscle glutamine. In severe sepsis metabolic changes correlate with the outcome of the patients, and amino acid metabolism seems to be characterised by low concentrations of muscle glutamine and high levels of the branched chain amino acids possibly indicating an inhibited intracellular glutamine formation in muscle tissue.

The early detection of the effects of surgical shock on the viscera

One hundred and one patients, in shock after operations were reviewed to examine the visceral effects on their prognoses. The shock was caused in 65 cases by hypovolaemia and in 36 cases by sepsis. The effects were studied on the heart and cardiovascular system, liver, kidneys, gastrointestinal system, central nervous system, lungs and blood clotting system. Surgical shock affected more frequently the lung and liver (P less than 0.05 and P less than 0.01). The lungs were most frequently involved in hypovolaemia (25 patients) and sepsis (25 cases). Pathology of the lung was associated with the highest mortality rate (P less than 0.005), followed by kidney (P less than 0.01) then heart and central nervous system (P less than 0.025). Involvement of the gastrointestinal tract or clotting system alone was not associated with higher mortality rates, except in the presence of other visceral derangements. Lung affection also had a greater mortality followed by kidney and the central nervous system. Involvement of one or several organs in failure to survive septic shock is dealt with in the discussion. It is concluded that visceral involvement secondary to shock could be of importance for prognosis.

Results of gastric neutralization with hourly antacids and cimetidine in 320 intubated patients with respiratory failure

In a retrospective analysis massive upper gastrointestinal (GI) hemorrhage, defined as blood loss requiring more than two units of blood transfusion over a 24-hour period, occurred in 40 (9.5 percent) of 420 intubated, mechanically ventilated patients with respiratory failure, irrespective of the etiology of the respiratory failure. In a prospective study hourly antacid gastric neutralization, maintaining the gastric pH over 5, the incidence of massive gastric bleeding was reduced to 3 (1.4 percent) of 210 patients. In 110 additional patients, cimetidine, a histamine H2 receptor blocker, was used to prevent gastric acid secretion; 3 (2.7 percent) of 110 patients had massive upper GI bleeding; all three had solitary chronic pyloric ulcers. We conclude that gastric neutralization, either with hourly antacids or with cimetidine, is effective in reducing the incidence of massive gastric hemorrhage in intubated, mechanically ventilated patients during respiratory failure. We recommend the use of either in all intubated patients with respiratory failure. In addition, in 17 patients who had gastric bleeding at the time of transfer to the respiratory intensive care unit, gastric neutralization with hourly antacids in 14 patients and with cimetidine in three patients stopped the bleeding in all 17 patients within 24 to 48 hours.

Synergistic effect of acute renal failure and respiratory failure in the surgical intensive care unit

A retrospective evaluation of the effect of renal and respiratory failure on mortality in our surgical intensive care unit was undertaken. The coexistence of combined renal and respiratory failure had a synergistic adverse effect on survival. Combined pulmonary and kidney failure appeared to develop simultaneously. A subset of patients with severe prerenal azotemia but without uremia had the highest mortality. These results are not consistent with the simple combination of single systems failure but rather suggest that renal and respiratory failure are makers of a generalized underlying defect.

Survial from acute renal failure with and without multiple organ dysfunction

A 10-year retrospective analysis has been carried out of 114 patients dialysed for acute renal failure. Fifty-eight patients, predominantly suffering from multiple organ failure, required treatment in an Intensive Therapy Unit (ITU); 56 less severely ill patients were treated in a Renal Unit. Overall survival in the former group was 36% and in the latter group 63%. In the first 5 years of the study, survival in the ITU patients was 31% and in the second 5 years, was 38% in spite of a trend towards increased severity of illness. These results challenge the view that haemodialysis is rarely worth-while in patients with multiple organ failure, and suggest that current management techniques have improved prognosis. The most important adverse factors continue to be old age, sepsis and gastrointestinal disease.