The effect of fiberoptic bronchoscopy on cerebral hemodynamics in patients with severe head injury.

STUDY OBJECTIVE: Concerns exist about the effect of flexible fiberoptic bronchoscopy (FFB) on intracranial pressure (ICP). We studied the effect of FFB on cerebral hemodynamics in patients with severe head injury. DESIGN: Prior to FFB, patients were anesthetized and muscle relaxants were given as necessary to eliminate coughing. Comparisons were made of mean arterial pressure (MAP), ICP, and cerebral perfusion pressure (CPP) prior to, during, and after FFB, as well as comparisons of mean cerebral hemodynamic values in an 8-hour period before and after FFB. Observations were made of changes in neurologic status post-FFB. SETTING: Surgical intensive care unit of Level 1 Trauma Center. PATIENT POPULATION: Fifteen patients with severe head injury in whom ICP was monitored and who required FFB for diagnosis of nosocomial pneumonia or treatment of lobar collapse. RESULTS: Pre-FFB ICP averaged 14.3 mm Hg (range, 6 to 26 mm Hg). During FFB, patients experienced a mean increase in ICP of 13.5 mm Hg above basal values (p = 0.0001). At peak ICP, MAP increased from a baseline of 92.3 mm Hg (SD +/- 16.1) to 111.5 mm Hg (+/- 13.9). Mean CPP was 83.7 mm Hg at peak ICP (range, 52 to 121 mm Hg), a 14.0% increase over baseline. The ICP and MAP returned to basal levels following bronchoscopy. No patient had a clinically significant increase in ICP or demonstrated any deterioration in Glasgow Coma Scale score or neurologic examination findings post-FFB. CONCLUSIONS: Although FFB causes an increase in ICP in patients with severe head injury, MAP also rises, and an adequate CPP is maintained. The ICP returns to basal levels after the procedure. When properly performed, FFB does not adversely affect neurologic status in patients with severe head injury.

Skin complications in the intensive care unit.

Critically ill patients usually have multiple risk factors for the development of pressure ulcers. Pressure ulcers involve all levels of tissue from bone to skin, and result from excessive pressure and shearing. Control of incontinence, maintenance of adequate oxygen delivery and nutritional support is the key to minimizing the effects of skin breakdown in the intensive care unit. Consistent assessment and surveillance of skin for early signs of pressure ulcer development are essential, as is an interdisciplinary approach with nursing specialists and surgical consultants for pressure ulcers that have developed.

Atrial septal lipomatous hypertrophy and ischemic heart disease: an unusual presentation.

Lipomatous hypertrophy of the interatrial septum consists of the abnormal accumulation of fatty tissue. We report a patient with unsuspected massive lipomatous hypertrophy of the interatrial septum scheduled to undergo coronary artery surgery. This patient had experienced atrial arrhythmias and obstructive symptoms preoperatively that were ascribed to her coronary artery disease (CAD). The perioperative anesthetic and surgical management of patients with lipomatous hypertrophy of the interatrial septum and CAD is discussed.

Fluid management of the trauma patient.

Hemodynamic instability in the trauma patient is most commonly secondary to blood loss and the accumulation of fluid in injured tissue. The etiologies of shock unrelated to hypovolemia must also be investigated. The treatment of hypovolemia in patients with non-cerebral trauma should begin with Ringer's lactate solution. Normal saline (0.9% sodium chloride) is appropriate for patients with head injury, alkalosis, or hyponatremia, but in large volumes may lead to metabolic acidosis. The role of colloids, hypertonic saline, and hemoglobin solutions in trauma resuscitation is unclear at the present time. Base deficit and lactate levels are useful as predictors of morbidity and mortality and can be used to guide resuscitation.

Comparison of methods of measurements of oxygen consumption in mechanically ventilated patients with multiple trauma: the Fick method versus indirect calorimetry.

OBJECTIVE: The purpose of this study was to compare the measurements of whole body oxygen consumption determined by the Fick method and by indirect calorimetry in mechanically ventilated patients with multiple trauma. DESIGN: A prospective, correlational, within-subjects design. SETTING: Surgical intensive care unit of a Level I trauma center. PATIENTS: Thirty-eight mechanically ventilated adults with multiple injuries who received a pulmonary artery catheter within 24 hrs of admission to the surgical intensive care unit. MEASUREMENTS AND MAIN RESULTS: After the initial resuscitation, simultaneous measurements of oxygen consumption (V(O2) by the reverse Fick equation and by indirect calorimetry were performed every 6 hrs for 24 hrs in normothermic patients who were at rest for at least 30 mins. At each measurement period, the mean V(O2) values determined by indirect calorimetry were significantly greater than the mean V(O2) values determined by the Fick method (time 1: 172+/-38 vs. 125+/-47 mL/min/m2, p < .0001; time 2: 170+/-31 vs. 130+/-48 mL/min/m2, p < .0001; time 3: 170+/-32 vs. 132+/-53 mL/min/m2, p < .0001; time 4: 169+/-29 vs. 130+/-60 mL/min/m2, p < .0002). By using the Bland and Altman technique, the mean bias was 41+/-3.95 mL/min/m2. Correlation coefficients of VO2 values between methods of measurements were statistically significant (r2 = .32, p = .0001; r2 = .32, p = .0001; r2 = .33, p = .0001; r2 = .18, p = .0001). CONCLUSIONS: Indirect calorimetry should be the preferred standard for measurement of oxygen consumption in severely injured patients.

Oxygen delivery is an important predictor of outcome in patients with ruptured abdominal aortic aneurysms.

OBJECTIVE: The purpose of this study was to evaluate the relation of oxygen delivery (DO2) to the occurrence of multiple organ dysfunction (MOD) in patients with ruptured abdominal aortic aneurysms (AAA). SUMMARY BACKGROUND DATA: Patients with ruptured AAA are at high risk for the development of MOD and death. Previous reports of high-risk general surgical patients have shown improved survival when higher levels of DO2 are achieved. METHODS: Hemodynamic data were collected at 4-hour intervals on 57 consecutive patients (mean age, 70.5 years) who survived 24 hours after repair of infrarenal ruptured AAA. Patients were resuscitated to standard parameters of perfusion (pulse, blood pressure, urine output, normal base deficit). MOD was determined based on six organ systems. Standard parametric (analysis of variance, t tests) and nonparametric (chi square, Wilcoxon) tests were used to compare hemodynamic data, red blood cell requirements, colon ischemia, and organ failure for patients with and without MOD. RESULTS: Patients who developed MOD had a significantly lower cardiac index and DO2 for the first 12 hours; the difference was most significant at 8 hours. Logistic regression analysis demonstrated that the strongest predictors of MOD were DO2, early onset of renal failure, and total number of red blood cells transfused. CONCLUSIONS: DO2 is an earlier and better predictor of MOD after ruptured AAA than previously identified risk factors. Failure to achieve a normal DO2 in the first 8 hours after repair is strongly associated with the development of MOD and a high mortality. Strategies to restore normal DO2 may be useful to improve outcome in these high-risk patients.

Oxygen consumption in the early postinjury period: use of continuous, on-line indirect calorimetry.

OBJECTIVE: To determine the patterns of oxygen consumption (Vo2) using indirect calorimetry (IC) for the first 24 hrs after serious blunt traumatic injury. DESIGN: Prospective, observational study. SETTING: Surgical intensive care unit of a Level 1 trauma center. PATIENTS: Sixty-six mechanically ventilated patients with blunt traumatic injury and Injury Severity Score >15. INTERVENTIONS: IC for 24 hrs postinjury. Patients were resuscitated to standard parameters of perfusion. MEASUREMENTS AND MAIN RESULTS: Mean patient age was 50.1+/-18.7 yrs with a mean Injury Severity Score 30.7+/-11.3). Mean Vo2 for all patients for the 24-hr study period was 168.5+/-29.5 mL/min/m2. The level of Vo2 was not related to Injury Severity Score, the number or combination of organ systems injured, or to the use of vasoactive agents. Patients >65 yrs of age had significantly lower Vo2 (P = .0038) compared with patients < or =50 yrs. Vo2 did not change over time after resuscitation to normal parameters of perfusion. Mean Vo2 was 156.5+/-63.2 mL/min/m2 in patients who developed multiple organ dysfunction, and 172.4+/-33.3 mL/min/m2 in those who did not develop multiple organ dysfunction (p = .16). CONCLUSIONS: Seriously injured patients are hypermetabolic in the early postinjury period. The level of Vo2 is unrelated to injury severity or number of organ systems involved. Elderly patients can be expected to have lower levels of Vo2. Vo2 does not change significantly in response to resuscitation to normal parameters of perfusion. Vo2 measured by IC did not predict the development of multiple organ dysfunction.