Biomedical subjects

H M Horst

Publications and source records attributed to H M Horst.

At least 19 recordsLinked to original sources

PubMed2001

Adrenal insufficiency in high-risk surgical ICU patients.

STUDY OBJECTIVES: To examine the incidence and response to treatment of adrenal insufficiency (AI) in high-risk postoperative patients. DESIGN: Prospective observational case series. SETTING: Large urban tertiary-care surgical ICU (SICU). PARTICIPANTS: Adults > 55 years of age who required vasopressor therapy after adequate volume resuscitation in the immediate postoperative period. INTERVENTIONS: Each patient underwent a cosyntropin (ACTH) stimulation test; at the discretion of the clinical team, some patients were empirically given hydrocortisone (100 mg IV q8h for three doses) before serum cortisol values became available. MEASUREMENTS: Adrenal dysfunction (AD), defined as serum cortisol < 20 microg/dL at all time points, with Delta cortisol (60 min post-ACTH minus baseline) of < or = 9 microg/dL; functional hypoadrenalism (FH), defined as serum cortisol < 30 microg/dL at all time points or Delta cortisol (60 min post-ACTH minus baseline) < or = 9 microg/dL; and AI, as the presence of either AD or FH. RESULTS: One hundred four patients were enrolled with a mean age (SD) of 65.2 +/- 16.9 years. AI (AD plus FH) was found in 34 of 104 patients (32.7%): AD was found in 9 patients (8.7%), FH in 25 patients (24%), and normal adrenal function in 70 patients (67.3%). The absolute eosinophil count was significantly higher in the combined AD and FH groups compared with the group with normal adrenal function (p < 0.05). Forty-six of 104 patients (44.2%) received hydrocortisone; 29 (63%) could be weaned from treatment with vasopressors within 24 h. This beneficial effect of hydrocortisone reached statistical significance in the FH group when compared with untreated patients (p < 0.031); a similar trend was seen in the AD group (p = 0.083). Mortality was also lower in the hydrocortisone-treated AI patients (5 of 23 [21%] vs 5 of 11 [45%] in those not receiving hydrocortisone; p < 0.01). CONCLUSION: There is a high incidence of AI among SICU patients > 55 years of age with postoperative hypotension requiring vasopressors. There is also a significant association between hydrocortisone replacement therapy, resolution of vasopressor requirements, and improved survival.

Adrenal Insufficiency↗

PubMed2001

Primary venorrhaphy for traumatic inferior vena cava injuries.

Primary venorrhaphy for traumatic inferior vena cava (IVC) injury has been criticized because of the potential for stenosis, thrombosis, and embolism. A retrospective study was performed to evaluate the morbidity and outcome of this method. Thirty-eight patients at our institution had traumatic injuries to the IVC between 1994 and 1999. Thirty (79%) were from firearms, five (13%) from stab wounds, and three (8%) from blunt trauma. Six patients died in the emergency department. The remaining 32 patients underwent exploratory celiotomy with 23 survivors and nine intraoperative deaths for a mortality rate of 28 per cent (nine of 32). Vascular control was achieved by manual compression in 44 per cent and by local clamping directly above and below the injury in 38 per cent. All repairs were by primary venorrhaphy, and no patient was treated with patch angioplasty or venous reconstruction. Three patients had caval ligation. Follow-up IVC imaging in 11 patients revealed that the IVC was patent in eight, narrowed in two, and thrombosed below the renal veins in one. One patient developed a pulmonary embolus. The vast majority of traumatic injuries to the IVC can be managed by direct compression or local clamping and primary venorrhaphy. Direct repairs are associated with a low thrombosis and embolic complication rate.

Adolescent↗

PubMed1999

Motor Activity Assessment Scale: a valid and reliable sedation scale for use with mechanically ventilated patients in an adult surgical intensive care unit.

OBJECTIVE: To establish the validity and reliability of a new sedation scale, the Motor Activity Assessment Scale (MAAS). DESIGN: Prospective, psychometric evaluation. SETTING: Sixteen-bed surgical intensive care unit (SICU) of a 937-bed tertiary care, university-affiliated teaching hospital. PATIENTS: Twenty-five randomly selected, adult, mechanically ventilated, nonneurosurgical patients who were admitted to the SICU > or = 12 hrs after surgery and were not receiving neuromuscular blockers. INTERVENTION: Four hundred assessments (eight per patient) were completed consecutively but independently, in pairs, at standardized times (both day and night) by two nurses who were preselected for each assessment from a pool of 32 pretrained SICU nurses. MEASUREMENTS AND MAIN RESULTS: To estimate validity, paired assessments (four/patient) compared the MAAS result with the subjective assessment using a 10-cm visual analog sedation scale, the percent change in blood pressure and heart rate from the previous 4-hr baselines, and the number of recent agitation-related sequelae. To estimate reliability, paired assessments (four/patient) measured correlation between assessments of the same type (e.g., MAAS-MAAS). Generalized estimating equations, which accounted for the four repeated measures in each patient, supported MAAS validity by finding a linear trend between MAAS and the visual analog scale (p < .001), blood pressure (p < .001), heart rate (p < .001), and agitation-related sequelae (p < .001) end points. The MAAS (kappa = 0.83 [95% confidence interval, 0.72 to 0.94]) was found to be more reliable than subjective assessment using the visual analog scale (intraclass correlation coefficient = 0.32 [95% confidence interval, 0.05 to 0.55]). CONCLUSIONS: The MAAS is a valid and reliable sedation scale for use with mechanically ventilated patients in the SICU. Further studies are warranted regarding the effect of MAAS implementation in our SICU on patient outcomes, such as quality of sedation and length of mechanical ventilation, as well as the use of the MAAS in other patient populations (e.g., medical).

Adult↗

PubMed1999

Anterior mediastinal abscess after closed sternal fracture.

BACKGROUND: Although sternal fractures after blunt chest trauma are markers for significant impact, the fracture itself is generally not associated with any specific wound complications. Mediastinal abscess and sternal osteomyelitis rarely occur after blunt trauma or cardiopulmonary resuscitation. Management of such complications is difficult, and requires a spectrum of operative procedures that range from simple closure to muscle flap reconstruction. METHODS: The trauma registry of a Level I trauma center was used to identify patients suffering a sternal fracture between January of 1994 and August of 1997. Records were reviewed for the mechanism of injury, length of hospital stay, and posttraumatic mediastinal abscess. RESULTS: Twenty-six patients were identified with sternal fracture. No clinically significant cardiac or aortic complications were noted. Three patients, all with a history of intravenous drug abuse and requiring central venous access in the emergency room, developed methicillin resistant Staphylococcus aureus mediastinitis. Sternal re-wiring and placement of an irrigation system successfully treated all three patients. CONCLUSION: Posttraumatic mediastinal abscess is an uncommon complication of blunt trauma in general and sternal fracture in particular. It can be recognized by the development of sternal instability. Risk factors include the presence of hematoma, intravenous drug abuse, and source of staphylococcal infection. Treatment with early debridement and irrigation can avoid the need for muscle flap closure.

Abscess↗

PubMed1998

Decrease in ventilation time with a standardized weaning process.

OBJECTIVE: To test the hypothesis that standardizing the process of weaning from mechanical ventilation would decrease ventilation times and length of stay in a surgical intensive care unit. DESIGN: Comparison of historic ventilation times with physician-directed weaning with those obtained with protocol-guided weaning by respiratory therapists. SETTING: Urban, teaching surgical intensive care unit with open admission policy and no dominant diagnosis related group. RESULTS: From January 1, 1995, through December 31, 1995, 378 patients who underwent physician-directed weaning from a ventilator had 64488 hours of ventilation, compared with 57796 ventilation hours in 515 patients with protocol-guided weaning (April 1, 1996, through May 31, 1997). The mean hours of ventilation decreased by 58 hours, a 46% decrease (P<.001). The length of hospital stay decreased by 1.77 days (29% change), while the Acute Physiology and Chronic Health Evaluation III score remained at 50 to 51. The number of reintubations did not change. The marginal cost savings was $603580. CONCLUSION: Protocol-guided weaning from mechanical ventilation leads to more rapid extubation than physician-directed weaning and has great potential for cost savings.

APACHE↗

PubMed1998

A comparison of rigid -v- video thoracoscopy in the management of chest trauma.

Between December 1, 1994 and April 1,1998, 44 thoracoscopic procedures were performed in 42 patients following chest injuries. Indications included exploration in 15, retained haemothorax in 10, continued bleeding after chest tube placement in 3, air leak in 5 and empyema in 11. Video thoracoscopy was used in 24 cases and rigid thoracoscopy in 20, including 14 patients in whom video thoracoscopy was contraindicated. There was no difference in the operative times, length of stay or incidence of complications. Two formal and 3 "mini" thoracotomies were used in the video thoracoscopy group. Three "mini" thoracotomies were required in the rigid thoracoscopy group. Rigid thoracoscopy is an effective tool that, in selected cases, increases the utility of thoracoscopy in the management of chest trauma and its complications.

Contraindications↗

PubMed1998

Reducing the duration of mechanical ventilation: three examples of change in the intensive care unit.

Mechanical ventilation is one of the most common medical therapies administered within ICUs. Similarly, the "weaning" or "liberation" of patients from mechanical ventilation is a common and extremely important task performed in ICUs and specialized ventilator units within hospitals. Various methods exist for assessing a patient's readiness to be liberated from mechanical ventilation and for conducting the weaning process. Clinicians working in ICUs frequently develop their own personal preferences regarding the best approach to weaning patients from ventilatory support. Therefore, variability in the practice of weaning patients from mechanical ventilation is frequently demonstrated, even within a single ICU. Recently, several randomized clinical trials have produced conflicting results regarding the best technique for carrying out the weaning process (e.g., spontaneous breathing trials, intermittent mandatory ventilation, pressure-support ventilation). Such conflicting findings have further illustrated the complexity of the weaning process and the difficulties in identifying the "best" medical practices for carrying out this endeavor. However, other investigations have suggested that the selection of an individual technique for weaning patients from mechanical ventilation may not be as important as employing a systematic approach to this medical process. Protocol-guided weaning of mechanical ventilation in the ICU setting, often performed by nonphysicians, has gained in acceptance as a result of these investigations. We describe the recent experiences of three ICUs which have demonstrated significant improvements in patient outcomes (e.g., shorter durations of mechanical ventilation, lower incidence of ventilator-associated pneumonia, fewer patient complications) as a result of implementing formal weaning protocols. Our hope is that these data will assist other hospitals in developing their own systematic guidelines and protocols for weaning patients from mechanical ventilation.

Clinical Protocols↗

PubMed1997

Rigid thorascopic debridement and continuous pleural irrigation in the management of empyema.

STUDY OBJECTIVE: To determine the role of rigid thoracoscopy and continuous pleural irrigation as an alternative to thoracotomy in critically ill patients. DESIGN/SETTING/PATIENTS/INTERVENTIONS: Thirteen patients with empyema (one bilateral) underwent thorascopic decortication and continuous postoperative irrigation with normal saline solution. Seven patients required preoperative ventilator support. MEASUREMENTS AND RESULTS: Double-lumen intubation was utilized in only two cases. Empyemas were drained effectively in all patients, including nine patients in whom dense adhesions were encountered. Mean duration of irrigation was 3.5 +/- 0.5 days. There were no deaths. One patient developed a recurrent empyema 1 week after resolution of symptoms and underwent thoracotomy. CONCLUSIONS: Rigid thorascopic decortication is an effective method for treating empyemas and can be considered before thoracotomy. It can be performed in patients who might not be candidates for video-assisted thorascopic approaches owing to inability to tolerate one-lung anesthesia or who have dense adhesions preventing lung collapse.

Adult↗

PubMed1996

Trauma pneumonectomy revisited: the role of simultaneously stapled pneumonectomy.

OBJECTIVE: The aim of this study was to compare simultaneously stapled pneumonectomy (SSP) with individual ligation (IND) as a method for performing urgent pneumonectomy (Py) for trauma. METHODS: Twelve patients who required Py were reviewed. SSP was performed in nine cases and IND in three cases. The two groups had statistically similar injury severity scores, presenting systolic blood pressures, and Trauma and Injury Severity Score derived probabilities of survival. An animal model of Py was developed, in which seven animals underwent SSP and seven underwent IND methods. Burst pressures of the pulmonary artery and bronchus were calculated after 14 days. RESULTS: There were no differences noted in survival rates between SSP (5 (56%)) and IND (1 (33%)), nor in incidence of bronchopleural fistula. The SSP group had a significantly shorter operative time compared with that of IND (88.9 +/- 14.3 minutes vs 213 +/- 57.8 minutes, respectively, p - 0.01). The animal study revealed no difference in burst pressures of the bronchus (SSP = 662.9 +/- 169.9 mm Hg vs. IND = 591.4 +/- 193.2 mm Hg, p = 0.752) or of the pulmonary artery (SSP = 554.3 +/- 195.1 mm Hg vs. IND = 477.7 +/- 247.5 mm Hg, p = 0.529). CONCLUSION: Survival after pulmonary injuries that require Py depends upon the rapidity of hilar control and of the procedures itself. Simultaneously stapled pneumonectomy is an effective and rapid method of dealing with such rare injuries.

Adult↗

PubMed1995

A technique revisited: hemodynamic comparison of closed- and open-chest cardiac massage during human cardiopulmonary resuscitation.

OBJECTIVE: To compare the hemodynamics of closed-chest cardiac massage vs. open-chest cardiac massage in patients resuscitated from cardiac arrest that occurred outside of the hospital. DESIGN: Prospective, non-outcome, case series. SETTING: Large urban emergency department. PATIENTS: Ten adult, normothermic, nontraumatic, out-of-hospital, cardiac arrest patients who failed advanced cardiac life support (ACLS) therapy. INTERVENTIONS: Patients presenting to the hospital in cardiac arrest were managed according to the ACLS protocol at the clinician's discretion. Proximal aortic and central venous pressure catheters were placed to measure arteriovenous compression- and relaxation-phase pressure gradients. After 5 mins of baseline measurements during closed-chest cardiac massage, patients underwent a left lateral thoracotomy, and open-chest cardiac massage was performed for 5 mins. MEASUREMENTS AND MAIN RESULTS: The mean coronary perfusion pressure and compression-phase pressure gradients were 7.3 +/- 5.7 and 6.2 +/- 5.4 mm Hg, respectively, during closed-chest cardiac massage, while increasing to 32.6 +/- 17.8 and 32.6 +/- 29.9 mm Hg, respectively, during open-chest cardiac massage. The differences between both measurements were statistically significant (p < .05). CONCLUSIONS: Open-chest cardiac massage is superior to closed-chest cardiac massage in providing relaxation-phase and compression-phase pressure gradients during cardiac arrest in patients failing current ACLS protocols. During open-chest cardiac massage, all patients exceeded the minimum coronary perfusion pressure of 15 mm Hg, which is recommended to obtain a return of spontaneous circulation. Further outcome studies are needed to determine the timeliness and appropriate indications for open-chest cardiac massage.

Aged↗

PubMed1995

Use of absorbable mesh as an aid in abdominal wall closure in the emergent setting.

A surgeon has many options available to aid in the closure of abdominal wall defects in the elective setting. In the emergent setting, active infection or contamination increases the likelihood of infection of permanent prosthetic material and limits the surgical options. In such settings, we have used absorbable mesh (Dexon) as an adjunct to fascial closure until the acute complications resolve. To evaluate the effectiveness of this technique, we reviewed the outcome of such closures in 26 critically ill patients. Between July 1987 and June 1993, 26 patients were identified who had placement of absorbable mesh as part of an emergent laparotomy at a major urban trauma center. Through a retrospective chart review, the incidence of complications and outcome of the closure were tabulated. Seven patients were initially operated on for trauma. Two of the patients had mesh placement at their initial procedure secondary to fascial loss from trauma. The remainder of the patients hd mesh placement during a subsequent laparotomy for complications related to their initial procedure. Indications for these laparotomies included combinations of wound dehiscence, intra-abdominal abscess, anastomotic disruption, and perforation. Mesh placement in patients with intra-abdominal infection created effectively open abdominal wounds that allowed continued abdominal drainage, but required extensive wound care. Despite the absorbable nature of the mesh and often prolonged hospital stay in these ill patients, none of them required reoperation for dehiscence, recurrence of intra-abdominal abscess, or infection of the mesh.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdominal Abscess↗

PubMed1994

Coagulation defects resulting from ambient temperature-induced hypothermia.

Ambient temperature-induced hypothermia noted in trauma patients is frequently accompanied by a bleeding diathesis despite "laboratory normal" coagulation values. To document this impression, the following experiment was conducted. Coagulation studies and platelet function studies were performed in ten minipigs during induced whole body hypothermia (40 degrees C to 34 degrees C) and rewarming. Cooling was achieved in 2 to 3 hours and rewarming took 4 to 5 hours. In addition, similar coagulation and platelet function studies were conducted on plasma samples from the same animals that were cooled and then rewarmed in a water bath. Platelet counts and function as measured by Sonoclot analysis and aggregation did not decrease significantly with hypothermia in either model. Plasma cooled in a water bath demonstrated abnormal PT and aPTT (p < 0.001). Whole body hypothermia demonstrated abnormal bleeding time and PT (p < 0.001). Ambient temperature-induced hypothermia produced significant coagulation defects in a porcine model. Some of the coagulation defects were most pronounced during rewarming.

Animals↗

PubMed1994

Primary common bile duct closure following exploration: an effective alternative to routine biliary drainage.

Primary closure of the common bile duct following exploration has been safely and effectively performed, as advocated by Halsted, provided no evidence of pancreatitis, cholangitis, or ampullary obstruction exists. Using this precedent, the operative management and clinical course of 29 patients undergoing common bile duct exploration (CBDE) for choledocholithiasis from 1986 to 1992 were reviewed. Ten patients had primary closure of the common bile duct (CBD) following choledochotomy and exploration, and 17 patients had t-tube placement. Two patients had CBDE through an enlarged cystic duct that was then ligated. Patients were selected for t-tube placement if they had pancreatitis, ascending cholangitis, evidence of retained stones, or ampullary obstruction. Two patients in this series died. No patient with primary closure of the CBD suffered a biliary complication including retained stones, biliary fistula, pancreatitis, or bile peritonitis. Serious systemic complications were comparable in both groups. The results of this series support the safety of primary common bile duct closure in selected cases.

Cholecystectomy↗

PubMed1993

Determination of gentamicin pharmacokinetics by bioelectrical impedance in critically ill adults.

This investigation compares the accuracy of calculating gentamicin pharmacokinetic parameters by a noninvasive body composition technique (bioelectrical impedance analysis; BIA) with an empiric method, against the two-point method as the criterion standard. A prospective concurrent open label design was used. The 32 medical and surgical intensive care unit beds at Henry Ford Hospital, a not-for-profit, university-affiliated teaching hospital, served as the setting. Twenty critical ill adults, Therapeutic Index Scoring System (TISS) = 4, who required gentamicin as part of their normal course of therapy for gram-negative bacillary infections, were evaluated. Gentamicin Vd and k were calculated by three methods. After measurement of body composition parameters by BIA, previously derived gentamicin dosing equations were used to predict gentamicin volume of distribution (Vd) and elimination rate constant (k) (BIA method). Empiric estimates of these parameters (Vd = 0.3L/kg and k derived from creatinine clearance) were compared with the BIA parameters against a criterion standard Vd and k determined from a two-point sampling of gentamicin serum concentrations. Measurements of BIA parameters and gentamicin serum concentrations were made in duplicate with coefficients of variation, < or = 2% and < or = 3%, respectively. The BIA and empiric methods produced resultant pharmacokinetic parameters (Vd and k) not different than those measured by the two-point method. There were no statistically significant differences in mean error (bias), or mean squared error (precision) for both Vd and k assessed by the empiric or BIA methods.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1993

The management of massive lower gastrointestinal bleeding.

To evaluate what has been the most effective surgical treatment for massive lower gastrointestinal bleeding, we reviewed the records of 31 patients who underwent colon resection for hemodynamic instability and/or the need for continued transfusions. These 31 patients underwent either segmental colectomy (21 patients) or subtotal colectomy (10 patients). Resections were performed for diverticular disease (19 patients), angiodysplasia (eight patients), acute ulceration (three patients), and polyps (one patient). The re-bleeding rate (mean follow-up 1 year) for subtotal colectomy was 0 per cent, segmental resection with positive angiography was 14 per cent, and segmental resection with negative angiography was 42 per cent. The complication rate including myocardial infarction, ARDS, pneumonia, and renal failure was highest (83 per cent) in those patients receiving segmental resection with a negative angiogram. The mortality rate was also highest for segmental resection patients with negative angiography (57 per cent). The results of this review suggest that segmental resection should be performed when the bleeding site is identified angiographically. Subtotal colectomy should be reserved for massive bleeding with negative angiography.

Aged↗

PubMed1993

Arterial injuries of the thoracic outlet: a ten-year experience.

Arterial injuries of the thoracic outlet are complex and require a precise plan for adequate management and prompt exposure of injured vessels. Our 10-year experience with 28 such injuries is reviewed. Arteriography was performed whenever possible in stable patients (15) and aided in planning the operative approach. Unstable patients with active bleeding, pulsatile or expanding hematoma, or pulse deficit were taken to the operating room without delay. A thoracic approach was required in 15 patients, and the exposure was extrathoracic in 12 patients. Airway was secured with liberal use of emergency endotracheal intubation (16 patients). Primary repair was possible in 16 patients, with grafting performed in eight and ligation in three. One vertebral artery injury was successfully controlled with embolization. Venous injuries were repaired in six patients and ligation was necessary in eight; there was no significant morbidity. Two patients died in this series from complications of severe hemorrhage. Significant morbidity was encountered from associated neurologic injuries in 15 patients. Stroke was evident in two patients, both of whom were moribund preoperatively. Proximal subclavian artery injuries were particularly more problematic and frequently required an interim anterior thoracotomy for early control of exsanguinating hemorrhage. Our philosophy in the management of these injuries and choices of exposure are discussed in detail.

Adolescent↗

PubMed1992

Necrotizing cellulitis caused by Legionella micdadei.

Legionella micdadei is primarily considered a pathogen of the pulmonary tract of immunocompromised patients, the majority of whom have been renal transplant recipients. We report the case of a necrotizing soft tissue infection in a cadaveric renal transplant recipient resulting in amputation of the left arm. Only one other extrathoracic bacteriologically documented L. micdadei infection has been reported in the literature.

Adult↗

PubMed1992

Severe pancreatico-duodenal injuries: the effectiveness of pyloric exclusion with vagotomy.

The operative management and clinical course of 17 patients treated for severe pancreatico-duodenal injuries from 1983 to 1990 was reviewed. The etiology of these injuries was gunshot wound in 15 patients; stab wound in 1 patient; and a motor vehicle accident in 1 patient. Seven patients presented in shock with a systolic blood pressure of less than 80. At exploration, 57 associated injuries were found in the 17 patients including 16 major vascular injuries. All patients were treated with pyloric exclusion and drainage. Vagotomy was performed in eight patients. None of these 17 patients were felt to have extensive enough damage to require pancreatico-duodenectomy. Two patients died in the immediate postoperative period of severe coagulopathy and two patients died of sepsis. Seven patients had complications related to the pancreatico-duodenal injury. All seven developed pancreatic fistulas; three also had pancreatitis and two developed multiple enterocutaneous fistulas. Systemic complications included pulmonary complications in eight patients and sepsis in five patients, including two patients with abdominal abscesses. Six patients bled in the immediate postoperative period secondary to coagulopathy. Three patients had complications related to pyloric exclusion. One developed afferent loop syndrome necessitating reoperation. The other two had marginal ulcers, which either perforated or bled and required reoperation. Of interest, neither of these two patients had vagotomy initially. The results of this series confirm the effectiveness of pyloric exclusion with vagotomy for severe pancreatico-duodenal injury.

Adolescent↗