Outcomes after emergency appendicectomy in patients with liver cirrhosis: a population-based cohort study from England

INTRODUCTION

The mortality risk after appendicectomy in patients with liver cirrhosis is predicted to be higher than in the general population given the associated risk of perioperative bleeding, infections and liver decompensation. This population-based cohort study aimed to determine the 90-day mortality risk following emergency appendicectomy in patients with cirrhosis.

METHODS

Adult patients undergoing emergency appendicectomy in England between January 2001 and December 2018 were identified from two linked primary and secondary electronic healthcare databases, the clinical practice research datalink and hospital episode statistics data. Length of stay, re-admission, case fatality and the odds ratio of 90-day mortality were calculated for patients with and without cirrhosis, adjusting for age, sex and co-morbidity using logistic regression.

RESULTS

A total of 40,353 patients underwent appendicectomy and of these 75 (0.19%) had cirrhosis. Patients with cirrhosis were more likely to be older (p < 0.0001) and have comorbidities (p < 0.0001). Proportionally, more patients with cirrhosis underwent an open appendicectomy (76%) compared with 64% of those without cirrhosis (p = 0.03). The 90-day case fatality rate was 6.67% in patients with cirrhosis compared with 0.56% in patients without cirrhosis. Patients with cirrhosis had longer hospital length of stay (4 (IQR 3-9) days versus 3 (IQR 2-4) days and higher readmission rates at 90 days (20% vs 11%, p = 0.019). Most importantly, their odds of death at 90 days were 3 times higher than patients without cirrhosis, adjusted odds ratio 3.75 (95% CI 1.35-10.49).

CONCLUSION

Patients with cirrhosis have a threefold increased odds of 90-day mortality after emergency appendicectomy compared to those without cirrhosis.

Cholecystectomy in patients with cirrhosis: a population-based cohort study from England

BACKGROUND

This population-based cohort study aimed to determine postoperative outcomes after emergency and elective cholecystectomy in patients with cirrhosis.

METHODS

Linked electronic healthcare data from England were used to identify all patients undergoing cholecystectomy between January 2000 and December 2017. Length of stay (LOS), re-admission, case fatality and the odds ratio of 90-day mortality were calculated for patients with and without cirrhosis, adjusting for age, sex and co-morbidity using logistic regression.

RESULTS

Of the total 69,141 eligible patients who underwent a cholecystectomy, 511 (0.74%) had cirrhosis. In patients without cirrhosis 86.55% underwent a laparoscopic procedure compared with 57.53% in patients with cirrhosis (p < 0.0001). LOS was longer in those with cirrhosis (3 IQR 1-8 vs 1 IQR 1-3 days,p < 0.0001). 90-day re-admission was greater in patients with cirrhosis, 36.79% compared with 14.95% in those without cirrhosis. 90-day case fatality after elective cholecystectomy in patients with and without cirrhosis was 2.79% and 0.43%; and 12.82% and 2.39% following emergency cholecystectomy. This equated to a 3-fold (OR 3.22, IQR 1.72-6.02) and a 4-fold (OR 4.52, IQR 2.46-8.33) increased odds of death at 90-days following elective and emergency cholecystectomy after adjusting for confounders.

CONCLUSION

Patients with cirrhosis undergoing cholecystectomy have an increased 90-day risk of postoperative mortality, which is significantly worse after emergency procedures.

The palliative management of non-islet cell tumour hypoglycaemia with glucocorticoids and somatostatin analogues in an unresectable hepatocellular carcinoma

Non-islet cell tumour hypoglycaemia (NICTH) results from paraneoplastic insulin-like growth factor-II (IGF-II) secretion and its potent insulin-like effect. It causes recurrent, often severe, hypoglycaemic episodes, which is detrimental to quality of life. There is limited evidence regarding best supportive care in unresectable tumours. A 76-year-old woman presented with hypoglycaemic collapse. A new diagnosis of unresectable hepatocellular carcinoma (HCC) was made. The IGF-II:IGF-I ratio was 11.0, which confirmed NICTH. The octreoscan showed avid disease. The main problem was symptomatic nocturnal hypoglycaemia. Curative treatment options were not possible in this case and treatment focused on preventing symptomatic hypoglycaemia. Inpatient treatment was with high carbohydrate nasogastric (NG) feeds, prednisolone and somatostatin analogue (octreotide) infusion. Once stabilised, the patient was discharged with NG feeds, prednisolone and a long-acting somatostatin analogue (sandostatin). The patient received successful end-of-life care with her family as per her wishes, without requiring readmission. The treatments were well-tolerated and effective in preventing symptomatic hypoglycaemic episodes. The combination of high carbohydrate NG feed with prednisolone and somatostatin analogues was effective in preventing symptomatic hypoglycaemia. Somatostatin analogues had a useful steroid sparing role. Larger case series are warranted to clarify the management of NICTH patients with placebo-controlled studies to determine the role of somatostatin analogues.

Mortality following elective and emergency colectomy in patients with cirrhosis: a population-based cohort study from England

BACKGROUND

Patients with cirrhosis undergoing colectomy have a higher risk of postoperative mortality, but contemporary estimates are lacking and data on associated risk and longer term outcomes are limited. This study aimed to quantify the risk of mortality following colectomy by urgency of surgery and stage of cirrhosis.

DATA SOURCES

Linked primary and secondary-care electronic healthcare data from England were used to identify all patients undergoing colectomy from January 2001 to December 2017. These patients were classified by the absence or presence of cirrhosis and severity. Case fatality rates at 90 days and 1 year were calculated, and cox regression was used to estimate the hazard ratio of postoperative mortality controlling for age, gender and co-morbidity.

RESULTS

Of the total, 36,380 patients undergoing colectomy, 248 (0.7%) had liver cirrhosis, and 70% of those had compensated cirrhosis. Following elective colectomy, 90-day case fatality was 4% in those without cirrhosis, 7% in compensated cirrhosis and 10% in decompensated cirrhosis. Following emergency colectomy, 90-day case fatality was higher; it was 16% in those without cirrhosis, 35% in compensated cirrhosis and 41% in decompensated cirrhosis. This corresponded to an adjusted 2.57 fold (95% CI 1.75-3.76) and 3.43 fold (95% CI 2.02-5.83) increased mortality risk in those with compensated and decompensated cirrhosis, respectively. This higher case fatality in patients with cirrhosis persisted at 1 year.

CONCLUSION

Patients with cirrhosis undergoing emergency colectomy have a higher mortality risk than those undergoing elective colectomy both at 90 days and 1 year. The greatest mortality risk at 90 days was in those with decompensation undergoing emergency surgery.

O2 Mortality following elective and emergency colorectal surgery in patients with cirrhosis: a population-based cohort study

Introduction

This population based cohort study, aimed to quantify the risk of mortality following colectomy in patients with cirrhosis by urgency of surgery and stage of cirrhosis.

Method

Linked primary and secondary-care electronic healthcare data from England was used to identify all patients undergoing colectomy from January 2001 to December 2017. Patients were classified into three cohorts, non-cirrhotics, compensated cirrhotics and decompensated cirrhosis and followed up for 90-days from the date of surgery. Cox proportional hazards models were used to estimate the hazard ratio (HR) of postoperative mortality.

Result

A total of 36380 eligible patients were included. Of these, 248(0.7%) had liver cirrhosis and 70% had compensated disease. The proportion undergoing a colectomy who had a diagnosis of cirrhosis increased from 0.40% in 2001 to 1.07% in 2017 (χ2(16, N = 36380)=50.53, P &lt; 0.0001).

Following elective colectomy, 90-day case fatality was 4% in non-cirrhotics , 7% in compensated cirrhotics and 10% in decompensated cirrhotics. Following emergency colectomy 90-day case fatality was higher, it was 16% in non-cirrhotics, 35% in compensated cirrhotics and 41% in decompensated cirrhotics. This corresponded to an adjusted 2-fold (HR 2.57(95% CI 1.75–3.76)) and 3-fold (3.43(95% CI 2.02–5.83)) increased mortality rate in compensated and decompensated cirrhotics respectively compared to non-cirrhotics following emergency colectomy.

Conclusion

Over the study period, the proportion of patients undergoing colectomy who had liver cirrhosis increased to 1 in every 100 colectomies. The 90-day case fatality rates were high in all patients with cirrhosis in both emergency and elective settings but the greatest mortality risk was seen in those with decompensation following emergency surgery.

Take-home Message

1 in 100 colectomy procedures are in patients with cirrhosis. These cirrhotic patients have a very high risk of postoperative mortality, especially, emergency colectomy in patients with decompensated cirrhosis.

A systematic review of the impact of portal vein pressure changes on clinical outcomes following hepatic resection

BACKGROUND

There are evolving data correlating elevated post-hepatic resection portal vein pressure (PVP) with risk of developing post-resection liver failure (PLF) and other complications. As a consequence, modulation of PVP presents a potential strategy to improve outcomes following liver resection (LR). The primary aim of this study was to review the existing evidence regarding the impact of post-resection PVP on clinical outcomes in patients undergoing a LR.

METHODS

Systematic literature searches of electronic databases in accordance with PRISMA were conducted. Changes in PVP and clinical outcomes following liver resection were defined according to the existing literature.

RESULTS

Ten studies, consisting of 712 patients with a median age 61 (52-68) years, were identified that met the inclusion criteria. Of those, 77% (n = 550) underwent a major LR and 27% (n = 195) of patients had cirrhosis. Following LR, the median (range) PVP increased from 11.4 mmHg (median baseline, range 7.3-16.4) to 15.9 mmHg (7.9-19). The overall median incidence of PLF was 19%. Six of the ten studies found an elevated PVP after LR predicted PLF. One study found elevated PVP after LR predicted mortality after LR.

CONCLUSION

Elevated PVP following hepatic resection was associated with increased rates of PLF. It was not possible to define a specific threshold PVP for predicting PLF. Modulation of PVP therefore presents a potential strategy to mitigate the incidence of LR. Future studies should standardize on reporting liver remnant and haemodynamics to better characterize clinical outcomes following LR.

Meta-analysis of survival outcomes following surgical and non surgical treatments for colorectal cancer metastasis to the lung

BACKGROUND

Controversy exists regarding the optimal management of colorectal lung metastases (CRLM). This meta-analysis compared surgical (Surg) versus interventional (chemotherapy and/or radiotherapy) and observational non-surgical (NSurg) management of CRLM.

METHODS

A systematic review of the major databases including Medline, Embase, SCOPUS and the Cochrane library was performed.

RESULTS

One randomized and nine observational studies including 2232 patients: 1551 (69%) comprised the Surg cohort, 521 (23%) the interventional NSurg group and 160 (7%) the observational NSurg group. A significantly higher overall survival (OS) was observed when Surg was compared to interventional NSurg at 1 year (Surg 88%, 310/352; interventional NSurg 64%, 245/383; odds ratio (OR) 2.77 (confidence interval (CI) 1.94-3.97), P = 0.001), at 3 years (Surg 59%, 857/1444; interventional NSurg 26%, 138/521; OR 2.61 (CI 1.65-4.15), P = 0.002), at 5 years (Surg 47%, 533/1144; interventional NSurg 23%, 45/196; OR 3.24 (CI 1.42-7.39), P = 0.009) and at 10 years (Surg 27%, 306/1122; interventional NSurg 1%, 2/168; OR 15.64 (CI 1.87-130.76), P = 0.031). Surg was associated with a greater OS than observational NSurg at only 1 year (Surg 92%, 98/107; observational NSurg 83%, 133/160; OR 6.69 (CI 1.33-33.58), P = 0.037) and was similar to observational NSurg at all other OS time points. Comparable survival was observed among Surg and overall NSurg cohorts at 3- and 5-year survival in articles published within the last 3 years.

CONCLUSIONS

Recent evidence suggests comparable survival with Surg and NSurg modalities for CRLM, contrasting to early evidence where Surg had an improved survival. Significant selection bias contributes to this finding, prompting the need for high powered randomized controlled trials and registry data.

Prehabilitation prior to surgery for pancreatic cancer: A systematic review

INTRODUCTION

Prehabilitation aims to improve fitness and outcomes of patients undergoing major surgery. This systematic review aimed to appraise current available evidence regarding the role of prehabilitation in patients undergoing oncological pancreatic resection.

METHODS

A systematic literature search of PUBMED, MEDLINE, EMBASE databases identified articles describing prehabilitation programmes before pancreatic resection for malignancy. Data collected included timing of prehabilitation, programme type, duration, adherence and post-operative outcome reporting.

RESULTS

Six studies, including 193 patients were included in the final analysis. Three studies included patients undergoing neoadjuvant therapy followed by resection and 3 studies included patients undergoing upfront resection. Time from diagnosis to surgery ranged between 2 and 22 weeks across all studies. Two studies reported a professionally supervised exercise programme, and four described unsupervised programmes. Exercise programmes varied from 5 days to 6 months in duration. Adherence to exercise programmes was better with supervised programmes (99% reaching weekly activity goal vs 85%) and patients not undergoing neoadjuvant therapy (90% reaching weekly activity goal vs 82%). All studies reported improvement in muscle mass or markers of muscle function following prehabilitation. Two studies reported the impact of Prehabilitation on postoperative outcomes and Prehabilitation was associated with lower delayed gastric emptying and a shorter hospital stay with no impact on other postoperative outcomes.

CONCLUSION

Early evidence demonstrates that Prehabilitation programmes may improve postoperative outcomes following pancreatic surgery. However current Prehabilitaton programmes for patients undergoing pancreatic resection report diverse exercise regimens with no consensus regarding timing or length of Prehabilitation, warranting a need for standardisation of Prehabilitation programmes in pancreatic surgery.

Meta-Analysis and Meta-Regression of Risk Factors for Surgical Site Infections in Hepatic and Pancreatic Resection

BACKGROUND

The risk factors for surgical site infection (SSI) after HPB surgery are poorly defined. This meta-analysis aimed to quantify the SSI rates and risk factors for SSI after pancreas and liver resection.

METHODS

The PUBMED, MEDLINE and EMBASE databases were systematically searched using the PRISMA framework. The primary outcome measure was pooled SSI rates. The secondary outcome measure was risk factor profile determination for SSI.

RESULTS

The overall rate of SSI after pancreatic and liver resection was 25.1 and 10.4%, respectively (p < 0.001). 32% of pancreaticoduodenectomies developed SSI vs 23% after distal pancreatectomy (p < 0.001). The rate of incisional SSI in the pancreatic group was 9% and organ/space SSI 16.5%. Biliary resection during liver surgery was a risk factor for SSI (25.0 vs 15.7%, p = 0.002). After liver resection, the incisional SSI rate was 7.6% and the organ space SSI rate was 10.2%. Pancreas-specific SSI risk factors were pre-operative biliary drainage (p < 0.001), chemotherapy (p < 0.001) and radiotherapy (p = 0.007). Liver-specific SSI risk factors were smoking (p = 0.046), low albumin (p < 0.001) and significant blood loss (p < 0.001). The rate of organ/space SSI in patients with POPF was 47.7% and in patients without POPF 7.3% (p < 0.001). Organ/space SSI rate was 43% in patients with bile leak and 10% in those without (p < 0.001).

CONCLUSIONS

The risk factors for SSI following pancreatic and liver resections are distinct from each other, with higher SSI rates after pancreatic resection. Pancreaticoduodenectomy has increased risk of SSI compared to distal pancreatectomy. Similarly, biliary resections during liver surgery increase the rates of SSI.

A systematic review and network meta-analysis of parenchymal transection techniques during hepatectomy: an appraisal of current randomised controlled trials

BACKGROUND

Major liver resection can lead to significant morbidity and mortality. Blood loss is one of the most important factors predicting a good outcome. Although various transection methods have been reported, there is no consensus on the best technique. This systematic review and network meta-analysis aims to characterise and identify the best reported technique for elective parenchymal liver transection based on published randomised controlled trials (RCT's).

METHODS

A systematic review was conducted using MEDLINE, EMBASE, and Cochrane Central to identify RCT's up to 5th June 2019 that examined parenchymal transection for liver resection. Data including study characteristics and outcomes including intraoperative (blood loss, operating time) and postoperative measures (overall and major complications, bile leaks) were extracted. Indirect comparisons of all regimens were simultaneously compared using random-effects network meta-analyses (NMA) which maintains randomisation within trials.

RESULTS

This study identified 22 RCT's involving 2360 patients reporting ten parenchymal transection techniques. Bipolar cautery has lower blood loss and shorter operating time than stapler (mean difference: 85 mL; 22min) and Tissue Link (mean difference: 66 mL; 29min). Bipolar cautery was ranked first for blood loss and operating time followed by stapler and TissueLink. Harmonic scalpel is associated with lower overall complications than Hydrojet (Odds ratio (OR): 0.48), BiClamp forceps (OR: 0.46) and clamp crushing (OR: 0.41).

CONCLUSION

Bipolar cautery techniques appear to best at reducing blood loss and associated with shortest operating time. In contrast, Harmonic scalpel appears best for overall and major complications. Given the paucity of data and selective outcome reporting, it is still hard to identify what is the best technique for liver resection. Therefore, further high-quality large-scale RCT's are still needed.

The effects of terlipressin and direct portacaval shunting on liver hemodynamics following 80% hepatectomy in the pig

Liver failure is the major cause of death following liver resection. Post-resection portal venous pressure (PVP) predicts liver failure, is implicated in its pathogenesis, and when PVP is reduced, rates of liver dysfunction decrease. The aim of the present study was to characterize the hemodynamic, biochemical, and histological changes induced by 80% hepatectomy in non-cirrhotic pigs and determine if terlipressin or direct portacaval shunting can modulate these effects. Pigs were randomized (n=8/group) to undergo 80% hepatectomy alone (control); terlipressin (2 mg bolus + 0.5-1 mg/h) + 80% hepatectomy; or portacaval shunt (PCS) + 80% hepatectomy, and were maintained under terminal anesthesia for 8 h. The primary outcome was changed in PVP. Secondary outcomes included portal venous flow (PVF), hepatic arterial flow (HAF), and biochemical and histological markers of liver injury. Hepatectomy increased PVP (9.3 ± 0.4 mmHg pre-hepatectomy compared with 13.0 ± 0.8 mmHg post-hepatectomy, P<0.0001) and PVF/g liver (1.2 ± 0.2 compared with 6.0 ± 0.6 ml/min/g, P<0.0001) and decreased HAF (70.8 ± 5.0 compared with 41.8 ± 5.7 ml/min, P=0.002). Terlipressin and PCS reduced PVP (terlipressin = 10.4 ± 0.8 mmHg, P=0.046 and PCS = 8.3 ± 1.2 mmHg, P=0.025) and PVF (control = 869.0 ± 36.1 ml/min compared with terlipressin = 565.6 ± 25.7 ml/min, P<0.0001 and PCS = 488.4 ± 106.4 ml/min, P=0.002) compared with control. Treatment with terlipressin increased HAF (73.2 ± 11.3 ml/min) compared with control (40.3 ± 6.3 ml/min, P=0.026). The results of the present study suggest that terlipressin and PCS may have a role in the prevention and treatment of post-resection liver failure.

The Composition of Poly(Ethylene Terephthalate) (PET) Surface Precipitates Determined at High Resolving Power by Tandem Mass Spectrometry Imaging

We present the first demonstration of a general method for the chemical characterization of small surface features at high magnification via simultaneous collection of mass spectrometry (MS) imaging and tandem MS imaging data. High lateral resolution tandem secondary ion MS imaging is employed to determine the composition of surface features on poly(ethylene terephthalate) (PET) that precipitate during heat treatment. The surface features, probed at a lateral resolving power of<200 nm using a surface-sensitive ion beam, are found to be comprised of ethylene terephthalate trimer at a greater abundance than is observed in the surrounding polymer matrix. This is the first chemical identification of PET surface precipitates made without either an extraction step or the use of a reference material. The new capability employed for this study achieves the highest practical lateral resolution ever reported for tandem MS imaging.

Portoenterostomy as a Salvage Procedure for Major Biliary Complications Following Hepaticojejunostomy

Major biliary complications that require surgical intervention after hepaticojejunostomy are rare and technically challenging. While the hepaticojejunostomy can be refashioned in most patients requiring surgical reexploration after anastomotic dehiscence, a selected few may require a portoenterostomy, which involves anastomosis of the jejunum to a decapsulated area of the liver to establish a conduit from the intrahepatic bile ducts to the intestine. Herein, we describe the technique where a portoenterostomy has been used to restore bilioenteric continuity in three patients where reconstruction with a hepaticojejunostomy was not feasible. All patients survived the procedure and two needed percutaneous transhepatic biliary dilatation after 5 years and 6 months, respectively. One patient died of unrelated causes 12 years after the initial procedure and the other two are alive with normal bilirubin and intrahepatic ducts at 14 and 4 years. In rare cases where hepaticojejunostomy is not feasible due to small, friable or inflamed hepatic ducts, portoenterostomy with transanastomotic stenting provides an effective way of saving life and restoring bilioenteric continuity. Although this is not a procedure to be recommended without due consideration of other options, we have shown it can be life-saving and provide good long-term results in combination with postoperative radiological intervention, when necessary.

Gemcitabine transcatheter arterial chemoembolization for unresectable hepatocellular carcinoma

BACKGROUND/AIMS

Transcatheter arterial chemoembolization (TACE) has been shown to increase survival in patients with unresectable hepatocellular carcinoma (HCC), however toxicity from commonly used agents limits its use in unresectable disease. Gemcitabine is a well tolerated chemotherapeutic agent with a high first pass clearance. In this study we evaluated a cohort of patients with unresectable HCC treated with gemcitabine-TACE alone.

METHODOLOGY

A review of all patients that underwent gemcitabine-TACE for unresectable HCC from 2002 to 2006 was performed. No patients were eligible for resection, liver transplantation or ablation. All patients received gemcitabine-TACE alone. The primary outcome measure was survival from first treatment. Secondary outcome measures included radiological response and toxicity.

RESULTS

55 patients underwent a total of 172 gemcitabine-TACE treatments for unresectable HCC. Median age was 64.7 years. All patients had Barcelona-Clinic Liver Cancer (BCLC) stage B (44%) or C (56%) disease. Median survival following gemcitabine-TACE was 8.8 months. 22% demonstrated a partial response and 61% had stable disease. 6% experienced grade 3/4 adverse events. There was 1 treatment related death.

CONCLUSIONS

Gemcitabine-TACE is well tolerated and appears to provide an alternative agent for patients with unresectable HCC undergoing chemoembolization.

Adherence to enhanced recovery after surgery protocols across a high-volume gastrointestinal surgical service

BACKGROUND AND AIMS

Enhanced recovery after surgery (ERAS) has been shown to improve outcomes for patients following gastrointestinal surgery. Data on protocol adherence and how this impacts on outcome are limited. This study examines how protocol adherence changes over time and determines how this impacts on outcome across a large-volume gastrointestinal surgical service.

MATERIALS AND METHODS

A prospective review of patients eligible for colorectal, liver and oesophagogastric ERAS over two 3-month periods in 2010 and 2011 was performed. End points included: length of stay (LOS), overall protocol adherence, individual modality adherence, reason for pathway deviation and patient outcomes.

RESULTS

172 patients (110 colorectal, 31 liver and 31 oesophagogastric) were evaluated. For each sub-speciality, the introduction of ERAS led to significant reductions in LOS that were sustained for the duration of the study. Adherence was achieved across 60% (colorectal), 75% (liver) and 88% (oesophagogastric) of individual pathway modalities. The major causes of pathway deviation were: post-operative nausea and vomiting (colorectal), pain (liver) and pulmonary complications (oesophagogastric).

CONCLUSIONS

Large-scale implementation of ERAS at a high-volume centre is feasible and offers many of the benefits demonstrated in controlled trials, but adherence may diminish over time.

Spatially resolved correlation of active and total doping concentrations in VLS grown nanowires

Controlling axial and radial dopant profiles in nanowires is of utmost importance for NW-based devices, as the formation of tightly controlled electrical junctions is crucial for optimization of device performance. Recently, inhomogeneous dopant profiles have been observed in vapor–liquid–solid grown nanowires, but the underlying mechanisms that produce these inhomogeneities have not been completely characterized. In this work, P-doping profiles of axially modulation-doped Si nanowires were studied using nanoprobe scanning Auger microscopy and Kelvin probe force microscopy in order to distinguish between vapor–liquid–solid doping and the vapor–solid doping. We find that both mechanisms result in radially inhomogeneous doping, specifically, a lightly doped core surrounded by a heavily doped shell structure. Careful design of dopant modulation enables the contributions of the two mechanisms to be distinguished, revealing a surprisingly strong reservoir effect that significantly broadens the axial doping junctions.

Surgical endoscopy training: the Joint Advisory Group on gastrointestinal endoscopy national review

BACKGROUND AND AIMS

Endoscopy performance is dependent on the technical ability and experience of the operator. There is anxiety among surgical trainees that certification to perform independent endoscopy to agreed national standards by the date of award of certificate of completion of training is not achievable. The aim of this study was to evaluate the delivery of endoscopy training to UK-based general surgery trainees.

MATERIALS AND METHODS

An electronic survey of general surgery trainees holding a national training number or in a locum appointment to training post between July and September 2010 was undertaken.

RESULTS

Two hundred and thirty-three trainees responded from all UK training regions. Stated subspeciality interests included coloproctology (47%), oesophagogastric/bariatric (22%) and hepatobiliary/pancreatic (10%) general surgery. 92% of trainees were training or planned to train in endoscopy, 62% of whom had registered with the Joint Advisory Group (JAG). Thirteen trainees had JAG certification in diagnostic upper GI endoscopy and eight in colonoscopy. There were high rates of dissatisfaction with endoscopy training nationally. Two thirds of trainees had no scheduled training lists. Conflicting elective/emergency commitments, competition and absence of training lists were the most common reasons for a failure to access endoscopy training.

CONCLUSIONS

Higher surgical trainees are failing to achieve national standards for endoscopy practice. There is an urgent need to address the deficiencies in endoscopy training to ensure a competent cohort of surgical endoscopists.

Comparison of liver parenchymal ablation and tissue necrosis in a cadaveric bovine model using the Harmonic Scalpel, the LigaSure, the Cavitron Ultrasonic Surgical Aspirator and the Aquamantys devices

OBJECTIVES

The amount of tissue that is ablated or necrosed at the line of parenchymal transection is of clinical significance in the interpretation of resection margin status following hepatic resection. The aim of this study was to define the extent of parenchymal ablation and necrosis in liver tissue using the Harmonic Scalpel, the LigaSure, the Cavitron Ultrasonic Surgical Aspirator (CUSA) and the Aquamantys dissector ex vivo.

METHODS

Mounted blocks of non-perfused bovine liver were transected using the Harmonic Scalpel, LigaSure, CUSA and Aquamantys devices. Outcome measures included parenchymal ablation (ablation band widths and weights) and tissue necrosis band widths along the line of transection. Each experiment was replicated five times.

RESULTS

All devices were associated with parenchymal ablation (Harmonic Scalpel, 4.73 ± 1.62 mm; LigaSure, 4.55 ± 2.02 mm; CUSA, 7.16 ± 2.87 mm; Aquamantys, 4.75 ± 1.43 mm) and tissue necrosis (Harmonic Scalpel, 1.07 ± 0.46 mm; LigaSure, 1.36 ± 0.36 mm; CUSA, 0.81 ± 0.21 mm; Aquamantys, 0.81 ± 0.36 mm).

CONCLUSIONS

The Harmonic Scalpel, LigaSure, CUSA and Aquamantys devices were associated with bands of tissue loss along the hepatic parenchymal transection line in this benchtop cadaveric model. This should be taken into account in the interpretation of resection margin status following liver resection.

Emerging roles for biomaterials in the treatment of liver disease

This review explores potential roles for biomaterials in the field of liver surgery and hepatology. The studies reviewed are presented in three sections. The first section discusses liver regeneration and strategies to modulate it. The second section outlines the pathophysiology of liver inflammation and fibrosis and highlights novel therapeutic targets. The final section summarises the current challenges in liver surgery and discusses how biomaterials may be used to address these challenges and focuses on early translational applications for biomaterials for drug delivery and liver surgery.

Prediction, prevention and management of postresection liver failure

Background

Postresection liver failure (PLF) is the major cause of death following liver resection. However, there is no unified definition, the pathophysiology is understood poorly and there are few controlled trials to optimize its management. The aim of this review article is to present strategies to predict, prevent and manage PLF.

Methods

The Web of Science, MEDLINE, PubMed, Google Scholar and Cochrane Library databases were searched for studies using the terms ‘liver resection’, ‘partial hepatectomy’, ‘liver dysfunction’ and ‘liver failure’ for relevant studies from the 15 years preceding May 2011. Key papers published more than 15 years ago were included if more recent data were not available. Papers published in languages other than English were excluded.

Results

The incidence of PLF ranges from 0 to 13 per cent. The absence of a unified definition prevents direct comparison between studies. The major risk factors are the extent of resection and the presence of underlying parenchymal disease. Small-for-size syndrome, sepsis and ischaemia–reperfusion injury are key mechanisms in the pathophysiology of PLF. Jaundice is the most sensitive predictor of outcome. An evidence-based approach to the prevention and management of PLF is presented.

Conclusion

PLF is the major cause of morbidity and mortality after liver resection. There is a need for a unified definition and improved strategies to treat it.

Management of unresectable symptomatic focal nodular hyperplasia with arterial embolization

Symptomatic focal nodular hyperplasia (FNH) of the liver can usually be treated safely with liver resection. However, in those patients in whom resection is not possible because of the location or size of the tumor or other patient factors, selective arterial embolization should be considered. Herein, the authors describe the use of arterial embolization to treat three women with symptomatic FNH and provide a review of the literature.

The effect of hepatic vascular inflow occlusion on liver tissue pH, carbon dioxide, and oxygen partial pressures: defining the optimal clamp/release regime for intermittent portal clamping

BACKGROUND

The optimal duration of hepatic vascular inflow occlusion (Pringle maneuver) and reperfusion during liver resection are not defined. The aim of this study was to describe the changes that occur in liver tissue pH, partial pressure of carbon dioxide (P(L)CO(2)), and partial pressure of oxygen (P(L)O(2)) and by using the P(L)CO(2) as a predictor of hepatocellular damage define the optimal clamp/release regime for intermittent portal clamping during liver resection.

METHODS

Continuous pH, P(L)CO(2), and P(L)O(2) measurements were obtained using a Paratrend multi-parameter sensor (Diametrics Medical Inc., Roseville, MN) in 13 patients undergoing elective partial liver resection. Patients were randomly allocated to undergo a 10-min clamp/5-min release regime (group 1) or a 20-min clamp/10-min release regime (group 2).

RESULTS

In group 1 (n = 6) P(L)CO(2) increased and pH decreased significantly after 10 min of clamping and returned to baseline within 5 min of reperfusion. In group 2 (n = 7) the P(L)CO(2) increased and pH decreased significantly after 10 min of clamping, with a further significant change after 20 min. Following 10 min of reperfusion, pH and P(L)CO(2) had not returned to baseline. P(L)O(2) did not change significantly with either intermittent portal clamping regime.

CONCLUSIONS

A reperfusion of 5 min is sufficient to restore the P(L)CO(2) and liver tissue pH to normal after 10 min of clamping, but more than 10 min of reperfusion is required after 20 min of clamping. To minimize hepatic ischemia during liver resection, a 10-min clamp/5-min release regime should be used.

Scaffolds for liver tissue engineering

This review focuses on the expanding role for biomaterials and polymer scaffolds in liver tissue engineering. Studies are subdivided into in vitro and in vivo approaches. The in vitro section of the review discusses the challenges specific to liver tissue engineering, and how the choice of scaffold and its structure influences the success of the regenerative medicine strategy. The in vivo section evaluates early attempts to stimulate liver repair with cell and growth factor therapies, their failings and how current approaches aim to solve these problems.

Surgeons and injury prevention: what you don't know can hurt you!

BACKGROUND

The most effective treatment for traumatic injuries is to prevent them from occurring. Currently, few surgeons receive any formal training in injury' control and prevention. This study was designed to test the knowledge of injury prevention principles among practicing surgeons, in order to identify areas in need of intensified educational efforts.

STUDY DESIGN

Survey questions designed by members of the American College of Surgeons Committee on Trauma were programmed into a specialized touch-screen computer, which was displayed at four different surgery and trauma meetings, including the ACS Clinical Congress in 1999 and 2000. Participants were questioned about their knowledge of trauma epidemiology, bicycle helmet effectiveness, child safety seat usage, suicide, and domestic violence.

RESULTS

Seventy-nine surveys were completed by surgeons, including 33 specializing in trauma care, and by 106 nurses attending trauma courses. Overall, the percentage of correct answers was 50%. There were no significant differences in survey scores between trauma surgeons and general surgeons, although both scored higher than trauma nurses. Areas where knowledge deficits were the most apparent included proper use of child safety seats, the effectiveness of airbags, the prevalence of suicide, and the annual cost of injury in America.

CONCLUSIONS

The majority of practicing surgeons and nurses, including those working at trauma centers, are unaware of the basic concepts of injury prevention. Advancements in the field of injury control will require efforts to educate medical professionals and the public.

Nonoperative management of pediatric blunt hepatic trauma

The purpose of this study was to examine the effect of operative versus nonoperative management of blunt hepatic trauma in children including transfusion practices. We reviewed the experience at our American College of Surgeons-verified Level I trauma center with pediatric commitment over a 5-year period. Children < or = 16 years of age suffering blunt liver injury as documented on admission CT scan were included in the study. Liver injuries identified on CT scan were classified according to the American Association for the Surgery of Trauma's Organ Injury Scaling system. All data are presented as mean +/- standard error. One case of pediatric liver trauma not identified on CT was excluded (prehospital cardiopulmonary resuscitation). Twenty-seven patients were included [age 9.3 +/- 1.0 years (range 3-16)]. Mechanisms of injury included motor vehicle crash (14), pedestrian struck by motor vehicle (7), bicycle crash (4), fall from height (1), and pedestrian struck by falling object (1). Trauma Score was 11.5 +/- 0.3. Distribution of Liver Injury Grade was as follows: grade I, 13; grade II, 9; grade III, 3; grade IV, 2; and grade V, 0. All five patients who underwent operative management had multiple organ injuries; three had concomitant splenic injury requiring operative repair; the remaining two had small bowel injury requiring repair. Hepatorrhaphy did not correlate with severity of liver injury: grade I, n = 1; II, n = 2; III, n = 1; and IV, n = 1. Three operated patients received blood transfusions. Twenty-two patients were managed with nonoperative treatment, of these only one required blood transfusion. No patients in the study died, three were transferred to subacute rehabilitation, one was transferred to another hospital, and 23 were discharged home. Our findings indicate that a majority of children with blunt hepatic injury as documented on CT scan can be managed with nonoperative treatment, and few require blood transfusions. Patients with multiple organ injury including simultaneous splenic injury are likely ideally managed through operative exploration and repair, whereas those with isolated liver injuries can be successfully managed nonoperatively.

Surgical residents' knowledge of injury prevention principles

BACKGROUND

Injury prevention is not routinely taught in medical school or surgical residency curricula. Because of the integral role surgeons play in the diagnosis and treatment of trauma, we sought to determine the knowledge base of injury prevention concepts of surgical residents training in a state's level 1 trauma centers.

METHODS

A written survey was given to general surgery residents at our state's three level 1 trauma centers. Twenty-one questions related to injury prevention were asked in addition to demographic data. Basic concepts of injury prevention, statistical knowledge of injury patterns, and knowledge of intentional violence were tested.

RESULTS

Sixty-two residents completed the survey. Only 9 respondents reported prior formal instruction in injury prevention. Overall performance was (mean +/- SD) 10.6 +/- 2.5 of 31 possible points, for a mean average score of 34% correct answers. Postgraduate year level, prior medical school instruction in injury prevention or months of experience on a trauma service did not correlate with improved scores. Specific question performance ranged from 2% to 82% correct responses. Questions regarding domestic violence (60%), risk of burns (65%), and incidence of trauma deaths (82%) were answered correctly most often, while injury prevention theory questions, such as components of the Injury Prevention Triangle (5%), definition of YPLL (2%), and annual cost attributable to injury (19%) were least often answered correctly.

CONCLUSIONS

These data indicate that general surgery residents are poorly educated regarding basic concepts of injury prevention. Importantly, a majority of respondents (69%) felt formal instruction in injury prevention should be included in their surgical residency curriculum.

Development and use of a prehospital-oriented EMS computer bulletin board service

OBJECTIVE

To describe a Level 1 trauma center's response to the need for centralized information for EMS providers by implementing a computer bulletin board service (BBS). This service permits rapid retrieval of continuing education and reference information as well as an electronic forum for EMS-related issues.

METHODS

A desktop computer with a modem supporting 14.4 kbps running Remote Access v2.01 is accessed by both local and toll-free telephone numbers. Users may connect using any personal computer or terminal equipped with a modem as no proprietary formats are used. The service is available 24 hours a day, free of charge, and requires users to register online.

RESULTS

The first 41 months of experience has seen 9,592 calls answered by the BBS. 1,372 users, who may be individuals or groups, have registered on the service. Usage occurs in every county in the sponsor's state. In one sample period, 49% of the activity was educationally related, followed by discussion forums (26%). The BBS is used most heavily in the afternoon and evening hours.

CONCLUSIONS

A prehospital-oriented EMS BBS has seen increasing utilization in its first 41 months of existence. It has rapidly established itself as a statewide mainstay of EMS information while being inexpensive to develop and maintain. It provides focused service to a target audience and is easily accessible. The development of similar local resources elsewhere is encouraged.

Longitudinal analysis of the impact of a level 1 trauma center designation at a university hospital

BACKGROUND

There have been no quantitative, longitudinal studies on the effect of Level 1 Trauma Center (TC) designation on a facility. The purpose of this study was to evaluate the impact of such designation.

STUDY DESIGN

In September 1990, a 416-bed core affiliate hospital of the state medical school system was state-designated as the Level 1 TC for 6 counties. Data collected from five concurrent 1-year periods after TC designation included case number and acuity of condition, length of hospital and ICU stays, preventable death rates, financial coverage, and neurosurgery and orthopaedic volume. No registry data were available before TC designation.

RESULTS

While the yearly number of cases remained stable, the overall severity of cases increased coincident with a 50% reduction in overtriage. The need for ICU services increased over 50%. Mean Injury Severity Score increased from 11.0 in year 1 to 13.8 in year 5. There was a 25% to 30% increase in severe neurosurgery injuries and in major orthopaedic trauma. There was no change in the "self-pay" financial category (12% to 16%) or the ratio of blunt to penetrating trauma (90:10).

CONCLUSIONS

With Level 1 TC designation in a noninner city setting, planners can expect a shift to more severely injured patients, but should not expect an increase in nonpaying patients. Increases in severe injuries will continue to place strain on the ICU. Impact on neurosurgeons and orthopaedic surgeons mandates their support in TC planning.

The hidden traps in decision making

Bad decisions can often be traced back to the way the decisions were made--the alternatives were not clearly defined, the right information was not collected, the costs and benefits were not accurately weighed. But sometimes the fault lies not in the decision-making process but rather in the mind of the decision maker. The way the human brain works can sabotage the choices we make. Eight psychological traps that are particularly likely to affect the way we make business decisions are examined. The anchoring trap leads us to give disproportionate weight to the first information we receive. The status-quo trap biases us toward maintaining the current situation--even when better alternatives exist. The sunk-cost trap inclines us to perpetuate the mistakes of the past. The confirming-evidence trap leads us to seek out information supporting an existing predilection and to discount opposing information. The framing trap occurs when we misstate a problem, undermining the entire decision-making process. The overconfidence trap makes us over-estimate the accuracy of our forecasts. The prudence trap leads us to be overcautious when we make estimates about uncertain events. And the recallability trap leads us to give undue weight to recent, dramatic events. The best way to avoid all the traps is awareness--forewarned is forearmed. The authors show how to take action to ensure that important business decisions are sound and reliable.

Assessment of executive function in patients with mild traumatic brain injury

BACKGROUND

The nature of functional deficit after mild traumatic brain injury (TBI) defined by Glasgow Coma Score of 13-15 is not fully described. This study explored the sensitivity of several neuropsychological tests to identify sequelae of mild traumatic brain injury (TBI).

METHODS

Eleven adult patients with mild TBI admitted to a Level 1 trauma center were studied. The battery of tests included the Wechsler Intelligence Scale for Children -Revised: Mazes Subtest, Trails A and B, the Boston Naming Test, The Multilingual Aphasia Examination: Controlled Oral Word Association Test, and the Paced Auditory Serial Addition Task.

RESULTS

Control subjects performed significantly better than patients with mild TBI on Trails A and B, the Controlled Oral Word Association Test, and Paced Auditory Serial Addition Task (subtests 2-4). No significant differences in performances between patients and controls was found for the Wechsler Intelligence Scale for Children -Revised: Mazes Subtest, Boston Naming Test, and Paced Auditory Serial Addition Task Subtest 1.

CONCLUSION

The results suggest that tests of specific frontal lobe executive functions are valuable in diagnosing and monitoring recovery from mild TBI.

The hidden traps in decision making

Bad decisions can often be traced back to the way the decisions were made--the alternatives were not clearly defined, the right information was not collected, the costs and benefits were not accurately weighted. But sometimes the fault lies not in the decision-making process but rather in the mind of the decision maker. The way the human brain works can sabotage the choices we make. John Hammond, Ralph Keeney, and Howard Raiffa examine eight psychological traps that are particularly likely to affect the way we make business decisions: The anchoring trap leads us to give disproportionate weight to the first information we receive. The statusquo trap biases us toward maintaining the current situation--even when better alternatives exist. The sunk-cost trap inclines us to perpetuate the mistakes of the past. The confirming-evidence trap leads us to seek out information supporting an existing predilection and to discount opposing information. The framing trap occurs when we misstate a problem, undermining the entire decision-making process. The overconfidence trap makes us overestimate the accuracy of our forecasts. The prudence trap leads us to be overcautious when we make estimates about uncertain events. And the recallability trap leads us to give undue weight to recent, dramatic events. The best way to avoid all the traps is awareness--forewarned is forearmed. But executives can also take other simple steps to protect themselves and their organizations from the various kinds of mental lapses. The authors show how to take action to ensure that important business decisions are sound and reliable.

Patient recall of therapeutic paralysis in a surgical critical care unit

STUDY OBJECTIVE

To investigate patient recall of therapeutic paralysis (TP) in a surgical critical care unit.

DESIGN

Prospectively applied structured interview of patients undergoing TP over 18 months.

SETTING

Surgical critical care unit with 27 beds at a tertiary care university teaching hospital.

PATIENTS

Forty patients admitted for postoperative care after coronary artery bypass graft surgery, trauma, or gastrointestinal surgery.

INTERVENTIONS

Patients received TP and concurrent sedation with benzodiazepines, propofol, and narcotics.

MEASUREMENTS AND MAIN RESULTS

After the end of TP patients were asked to recall the experience, and their responses were ranked on a four-point ordinal scale. Four of 11 patients recalled mostly negative events and experiences with TP, such as sleeplessness, discomfort, pain, anxiety, and inconsistent caregiver communication. All patients with recall experienced fear, anxiety, and sleeplessness. Single-drug therapy with propofol and inadequate benzodiazepine dosing were linked to patient recall.

CONCLUSIONS

Patient recollection from TP may be more common than appreciated and is generally unpleasant. Adequate dosing with benzodiazepines and narcotics is warranted to prevent recall and discomfort.

Even swaps: a rational method for making trade-offs

Making wise trade-offs is one of the most important and difficult challenges in decision making. Needless to say, the more alternative you're considering and the more objectives you're pursuing, the more trade-offs you'll need to make. The sheer volume of trade-offs, however, is not what makes decision making so hard. It's the fact that each objective has its own basis of comparison, from precise numbers (34% versus 38%) to relationships (high versus low) to descriptive terms (red versus blue). You're not just trading off apples and oranges; you're trading off apples and oranges and elephants. How do you make trade-offs when comparing widely disparate things? In the past, decision makers have relied mostly on instinct, common sense, and guesswork. They've lacked a clear, rational, and easy-to-use trade-off methodology. To help fill that gap, the authors have developed a system-which they call even swaps-that provides a practical way of making trade-offs among a range of objectives across a range of alternatives. The even-swap method will not make complex decisions easy; you'll still have to make hard choices about the values you set and the trades you make. What it does provide is a reliable mechanisms for making trades and a coherent framework in which to make them. By simplifying and codifying the mechanical elements of trade-offs, the even-swap method lets you focus all your mental energy on the most important work of decision making: deciding the real value to your company of different courses of action.

Air bags alone compared with the combination of mechanical restraints and air bags: implications for the emergency evaluation of crash victims

BACKGROUND

Air bags (ABs) may be perceived by the public and physicians as protection for thoracoabdominal injuries. This study compares injury patterns when air bags are used alone with injury patterns when air bags plus mechanical restraints (MRs) are used.

METHODS

Patients treated over a 4-year period with emergency medical services-documented AB deployment alone (n = 16) or AB plus MR (n = 22) were identified by trauma registry query. Medical records were reviewed and injuries recorded.

RESULTS

Air bag-alone users had more severe overall (injury severity score > or = 15:9 vs 5), chest (abbreviated injury score [AIS] > or = 3:5 vs 1), and abdominal injuries (AIS > or = 3:6 vs 0). They required more tube thoracostomies (5 vs 0) and laparotomies (6 vs 0), longer hospitalizations (11.9 +/- 3.2 vs 5.3 +/- 1.4 days), and more intensive care unit admissions (8 vs 1). Craniofacial injuries (AIS > or = 3:6 vs 6) and fractures were similar. More victims using air bags alone required impatient rehabilitation and some patients died (6 vs 1).

CONCLUSIONS

Crash victims using air bags alone (vs AB plus MR) had increased injury severity, hospitalizations, thoracoabdominal procedures, and rehabilitation. Physicians must be aware of the incomplete protection by air bags alone.

Cognitive trauma care is undervalued: adult splenic injury as a paradigm

Nonoperative management (NOM) of adult splenic injury is evolving. Economic aspects of NOM have not been examined. We hypothesize that NOM reduces hospital and professional charges. Surgeon, radiologist, and hospital charges and reimbursements, and clinical outcome were obtained for 77 consecutive adult splenic injury patients (> or = 15 years old) over a 3-year period. NOM succeeded in 30 of 31 patients. NOM was associated with lower surgeon fee ($1,148 vs $4,452; P < 0.0001), surgeon reimbursement ($587 vs $2,773; P = 0.0001), and hospital charge ($18,982 vs $48,790; P = 0.001) relative to operative management. Radiologist fee ($1,776 vs $2,285) and reimbursement ($1,069 vs $1,537) were not significantly affected. No significant difference existed between surgeon (primary care provider) and radiologist reimbursement for NOM. ISS poorly correlated with economic variables. We conclude that cost reductions are another potential advantage of NOM. Surgeon reimbursement for the cognitive skills involved in NOM is minimal. Future health finance policy should recognize the cognitive aspects of trauma care.

Sternal fractures in blunt chest trauma: a practical algorithm for management

A retrospective review of the medical records of blunt trauma patients with sternal fracture admitted to a level 1 trauma center from June 1990 to June 1993 was undertaken to determine the relationship between sternal fractures and clinically significant myocardial injury, and to assess the usefulness of cardiac evaluation and monitoring in these patients. Of 33 patients with sternal fracture, 31 were in motor vehicle crashes and 2 were pedestrians struck. All had Glasgow Coma Scale score = 15. No patient had a severe, life-threatening, associated injury (Abbreviated Injury Score of >3). No electrocardiogram or echocardiogram showed evidence of acute injury or ischemia. No arrhythmias requiring treatment were noted. No CPK-MB fraction was >5%. These results show that sternal fracture is not a marker for clinically significant myocardial injury. The management of sternal fracture patients should be directed toward the treatment of associated injuries.

Drugs for amnesia in the ICU

OBJECTIVE

This review focuses on how patients' recall of their stay in the ICU can be modified pharmacologically.

DATA SOURCES

Computerized MEDLINE and PAPERCHASE searches of English- and foreign-language published research from 1966 to 1995, bibliographies, pharmaceutical and personal files, and conference abstract reports.

STUDY SELECTION

All abstracts from uncontrolled and controlled clinical trials were reviewed.

DATA EXTRACTION

Study design, population, results, and safety information were retained. Efficacy conclusions were drawn from controlled trials.

DATA SYNTHESIS

Patients without cerebral injury may recall mental and physical discomfort during their stay in the ICU. All benzodiazepines produce amnestic effects, but the short duration of action, lack of long-acting metabolites, and potent amnestic effects make lorazepam and midazolam preferable in this setting. Infusions of propofol for conscious sedation produce concentrations below those required for consistent amnesia. Opioids generally do not produce amnesia; however, end-organ failure and use of high doses of opioids may increase plasma concentrations to levels that produce impairment of learning and various degrees of amnesia. High infusion rates of ketamine may be required for satisfactory amnesia and pain control (with coadministration of benzodiazepine). Barbiturates and haloperidol do not impair memory in patients who are not critically ill. Antihistamines and anticholinergics that do not penetrate the central nervous system do not produce amnesia. Flumazenil may induce recall.

CONCLUSIONS

Patients may remember their stay in the ICU, depending on the type of injury and the drug therapy. Of the drugs presented, benzodiazepines most reliably provide anterograde amnesia, whereas ketamine and propofol exhibit dose-dependent effects on memory.

Drugs for amnesia in the ICU

OBJECTIVE: This review focuses on how patients' recall of their stay in the ICU can be modified pharmacologically. DATA SOURCES: Computerized MEDLINE and PAPERCHASE searches of English- and foreign-language published research from 1966 to 1995, bibliographies, pharmaceutical and personal files, and conference abstract reports. STUDY SELECTION: All abstracts from uncontrolled and controlled clinical trials were reviewed. DATA EXTRACTION: Study design, population, results, and safety information were retained. Efficacy conclusions were drawn from controlled trials. DATA SYNTHESIS: Patients without cerebral injury may recall mental and physical discomfort during their stay in the ICU. All benzodiazepines produce amnestic effects, but the short duration of action, lack of long-acting metabolites, and potent amnestic effects make lorazepam and midazolam preferable in this setting. Infusions of propofol for conscious sedation produce concentrations below those required for consistent amnesia. Opioids generally do not produce amnesia; however, end-organ failure and use of high doses of opioids may increase plasma concentrations to levels that produce impairment of learning and various degrees of amnesia. High infusion rates of ketamine may be required for satisfactory amnesia and pain control (with coadministration of benzodiazepine). Barbiturates and haloperidol do not impair memory in patients who are not critically ill. Antihistamines and anticholinergics that do not penetrate the central nervous system do not produce amnesia. Flumazenil may induce recall. CONCLUSIONS: Patients may remember their stay in the ICU, depending on the type of injury and the drug therapy. Of the drugs presented, benzodiazepines most reliably provide anterograde amnesia, whereas ketamine and propofol exhibit dose-dependent effects on memory.