Effect of expiratory flow limitation on ventilation/perfusion mismatch and perioperative lung function during pneumoperitoneum and Trendelenburg position

BACKGROUND

Laparoscopic surgery and Trendelenburg position may affect the respiratory function and alter the gas exchange. Further the reduction of the lung volumes may contribute to the development of expiratory flow limitation (EFL). The latter is associated with an increased risk of postoperative pulmonary complications. Our aim was to investigate the incidence of EFL and to evaluate its effect on pulmonary function and intraoperative V/Q mismatch.

METHODS

This is a prospective study on patients undergoing elective laparoscopic gynecological surgery. We evaluated respiratory mechanics, V/Q mismatch and presence of EFL after anesthesia induction, during pneumoperitoneum and Trendelenburg position and at the end of surgery. Intraoperative gas exchange and hemodynamic were also recorded. Clinical data were collected until seven days after surgery to evaluate the onset of pulmonary postoperative complications (PPCs).

RESULTS

Among the 66 patients enrolled, 25/66 (38%) exhibited EFL during surgery, of whom 10/66 (15%) after anesthesia induction, and the remaining 15 patients after pneumoperitoneum and Trendelenburg position. Median PEEP able to reverse flow limitation was 7 [7-10] cmH2O after anesthesia induction and 9 [8-15] cmH2O after pneumoperitoneum and Trendelenburg position. Patients with EFL had significantly higher shunt (17 [2-25] vs. 9 [1-19]; P=0.05), low V̇/Q̇ (27 [20-70] vs. 15 [10-22]; P=0.05) and high V̇/Q̇ (10 [7-14] vs. 6 [4-7]; P=0.024). At the end of surgery, only high V/Q was significantly higher in EFL patients. Further, they exhibited higher incidence of postoperative pulmonary complication (48% (12/25) vs. 15% (6/41), P=0.005), hypoxemia and hypercapnia (80% [20/25] vs. 32% [13/41]; P<0.001).

CONCLUSIONS

Expiratory flow limitation is a common phenomenon during gynecological laparoscopic surgery associated with worsen gas exchange, increased V/Q mismatch and altered lung mechanics. Our study showed that patients experiencing EFL during surgery showed a higher risk for PPCs.

Comparison of airway management without neuromuscular blockers in laparoscopic gynecological surgery

New generation supraglottic airway devices are suitable for airway management in many laparoscopic surgeries. In this study, we evaluated and compared the ventilation parameters of the laryngeal mask airway-supreme (LM-S) and endotracheal tube (ETT) when a neuromuscular blocker (NMB) agent was not used during laparoscopic gynecological surgery. The second outcome was based on the evaluation of the surgical view because it may affect the surgical procedure.This was a randomized study that enrolled 100 patients between 18 and 65 years old with an ASA I-II classification. Patients were divided into 2 groups: Group ETT and Group LM-S. Standard anesthesia and ventilation protocols were administered to patients in each group. Ventilation parameters [airway peak pressure (Ppeak), mean airway pressure (Pmean), total volume, and oropharyngeal leak pressure] were recorded before, after, and during peritoneal insufflation and before desufflation, as well as after the removal of the airway device. Perioperative surgical view quality and the adequacy of the pneumoperitoneum were also recorded.The data of 100 patients were included in the statistical analysis. The Ppeak values in Group ETT were significantly higher in the second minute after airway device insertion. The Ppeak and Pmean values in Group ETT were significantly higher before desufflation and after removal of the airway device. No significant differences were found between the groups in terms of adequacy of the pneumoperitoneum or quality of the surgical view.The results of this study showed that gynecological laparoscopies can be performed without using a NMB. Satisfactory conditions for ventilation and surgery can be achieved while sparing the use of muscle relaxants in both groups despite the Trendelenburg position and the pneumoperitoneum of the patients, which are typical for laparoscopic gynecological surgery. The results are of clinical significance because they show that the use of a muscle relaxant is unnecessary when supraglottic airways are used for these surgical procedures.

Assessment of efficacy and safety of EUS-guided biliary drainage: a systematic review

BACKGROUND AND AIMS

EUS-guided biliary drainage (EUS-BD) has emerged as an alternative procedure after failed ERCP. However, limited data on the efficacy and safety of EUS-BD are available. Therefore, a systematic review was conducted to evaluate the efficacy and safety of EUS-BD and to evaluate transduodenal (TD) and transgastric (TG) approaches.

METHODS

PubMed and EMBASE were searched to identify relevant studies published in the English language for inclusion in this systematic review and meta-analysis. Data from eligible studies were combined to calculate the cumulative technical success rate (TSR), functional success rate (FSR), and adverse-event rate of EUS-BD and the pooled odds ratio of TSR, FSR, and adverse-event rate of the TD approach when compared with the TG approach.

RESULTS

Forty-two studies with 1192 patients were included in this study, and the cumulative TSR, FSR, and adverse-event rate were 94.71%, 91.66%, and 23.32%, respectively. The common adverse events associated with EUS-BD were bleeding (4.03%), bile leakage (4.03%), pneumoperitoneum (3.02%), stent migration (2.68%), cholangitis (2.43%), abdominal pain (1.51%), and peritonitis (1.26%). Ten studies were included in the meta-analysis for comparative evaluation of TD and TG approaches for EUS-BD. Compared with the TG approach, the pooled odds ratio of the TSR, FSR, and adverse-event rate of the TD approach were 1.36 (95% CI, .66-2.81; P > .05), .84 (95% CI, .50-1.42; P > .05), and .61 (95% CI, .36-1.03; P > .05), respectively, which indicated no significant difference in the TSR, FSR, and adverse-event rate between the 2 groups.

CONCLUSIONS

Although it is associated with significant morbidity, EUS-BD is an effective alternative procedure for relieving biliary obstruction. There was no significant difference between the TD and TG approaches for EUS-BD.

[Prognostic factors related to mortality in newborns with jejunoileal atresia]

BACKGROUND

Jejuno-ileal atresia is one of the main causes of intestinal obstruction in neonates. The origin is vascular accidents in the fetal intestine. It is an entity that requires early and specialist management.

OBJECTIVE

to know the factors related to mortality in neonates with jejunoileal atresia.

METHODS

Case-control nested in a cohort design, comparative study during ten years, between deceased and survivors analyzing factors related to mortality before surgery and during surgery and in the postoperative course.

RESULTS

We analyzed 70 patients in 10 years, there were 10 deaths (14.2%). No one had a prenatal diagnosis. Factors related to mortality were: intestinal perforation with a relative risk (RR) of 4.4, peritonitis (RR: 5.6), the need of stomas (RR: 4.9), the presence of sepsis (RR: 4.6) and when the residual small bowel length was below 1 meter (RR: 7.4).

CONCLUSION

The delay in diagnosis causes late intervention and increased mortality delayed diagnosis promotes late transport of the neonate and enhances mortality, factors associated with mortality related to intestinal perforation. It is necessary to spread this disease in the medical community to improve prenatal and postnatal diagnosis.

Pneumoperitoneum after percutaneous endoscopic gastrostomy among adults in the intensive care unit: incidence, predictive factors, and clinical significance

The significance of post percutaneous endoscopic gastrostomy (PEG) pneumoperitoneum (PNP) is unclear. We studied patients in our intensive car unit who underwent PEG placement to better understand the significance of post PEG PNP at our institution. We identified all intensive care unit patients who underwent PEG placement between the years of 2000 and 2009. A review of 318 consecutive PEG procedures was performed. Radiographic imaging was reviewed for up to 14 days post PEG, noting the presence of PNP. The presence of common comorbidities and PEG-related complications were recorded. Of the 318 patients, radiologic imaging was not taken within 14 days in 37 patients. Forty-five patients were found to have PNP on imaging for an incidence of 16 per cent (45/281). Eight patients were found to require either surgical or endoscopic emergent intervention post PEG. Four of these had PNP on imaging. Post PEG PNP was associated with increased likelihood for complications requiring emergent surgical intervention (P = 0.0078) and 30-day mortality post PEG insertion (P = 0.0216). The presence of common comorbid conditions was not a significant determinant of post PEG PNP.

The incidence and clinical significance of pneumoperitoneum after percutaneous endoscopic gastrostomy: a review of 722 cases

Percutaneous endoscopic gastrostomy (PEG) is the procedure of choice for establishing enteral access in patients unable to take oral feedings. Serious complications are rare; however, misplaced PEGs and PEG/Jejunums can lead to hollow viscus injuries with intra-abdominal contamination and subsequent peritonitis, septicemia, and death. The presence of free intra-abdominal air is a reliable indicator of a perforated viscus and often points to a surgical emergency; however, in the case of PEGs, pneumoperitoneum without a perforated viscus, or "benign pneumoperitoneum" creates a diagnostic dilemma. To determine the incidence and clinical significance of pneumoperitoneum after PEG or PEG/Jejunum (J) we reviewed the records of 722 patients who underwent these procedures at our institution. Of 39 patients found to have free air after PEG/PEG/J placement, 33 (85%) had "benign pneumoperitoneum" and were discharged without complication or surgical intervention. Of the six patients with serious complications related to their procedure, five (83%) had clinical signs of intra-abdominal complications (peritonitis) that helped guide their management. Of these six patients, the two receiving abdominal radiographs instead of abdominal CT scanning had a 50 per cent negative laparotomy rate. We present an algorithm for the management of patients found to have pneumoperitoneum after PEG or PEG/J placement.

Pneumoperitoneum after percutaneous endoscopic gastrostomy in patients in the intensive care unit

Percutaneous endoscopic gastrostomy (PEG) has been associated with up to a 55 per cent incidence of pneumoperitoneum in the literature. A review was conducted of 120 consecutive PEG tube insertions in patients in the intensive care unit (ICU) to determine the incidence and significance of postprocedural pneumoperitoneum in this population. One hundred twenty consecutive PEG insertions in patients in the ICU were retrospectively reviewed. Chest radiographs were reviewed for 48 hours postprocedure, noting if any pneumoperitoneum was apparent on radiologic examination. If present, the time to resolution was noted. Documented PEG complications were also examined. Post-PEG pneumoperitoneum was detected in 6.7 per cent of patients in the ICU. Mean time to resolution was 2.7 days. The complication rate was 10.8 per cent, including dislodgement requiring laparotomy, transcolonic placement, and upper gastrointestinal bleeding. There were no complications resulting from PEG placement in patients with postprocedural pneumoperitoneum. Two transcolonic PEGs were undetected by postprocedure chest radiographs. The incidence of post-PEG pneumoperitoneum in our ICU population was 6.7 per cent. We believe that this incidence, although lower than historical rates, accurately reflects the current rate of detectable pneumoperitoneum in patients in the ICU. PEG-related complications were not associated with postprocedure pneumoperitoneum.

Clinical significance of elevated intraabdominal pressure during common conditions and procedures

INTRODUCTION

Pregnancy, obesity, peritoneal dialysis, pneumoperitoneum, prone position and application of positive end-expiratory pressure are associated with elevated intraabdominal pressure (lAP).

OBJECTIVE

To review the relation between these conditions and procedures, and intraabdominal hypertension (IAH) or abdominal compartment syndrome (ACS).

METHODS

Search of PubMed and Google Scholar and review of article bibliographies.

RESULTS AND CONCLUSION

Only obesity, peritoneal dialysis, and pneumoperitoneum are associated with symptoms related to IAH and these symptoms are reversible.

True incidence and clinical significance of pneumoperitoneum after PEG placement: a prospective study

BACKGROUND

PEG is a widely used method for providing nutritional support. Although pneumoperitoneum is a known finding after PEG placement, its true incidence is subject to debate. Small retrospective studies have found varied rates of free air after PEG placement.

PATIENTS

There were a total of 65 patients.

OBJECTIVE

To assess the true incidence of pneumoperitoneum and its clinical significance.

DESIGN

Prospective study.

SETTING

Long Island Jewish Medical Center.

INTERVENTIONS

We obtained upright and anterior-posterior chest radiographs of 65 patients within 3 hours after PEG placement. Type of PEG tube, gauge of the needle used, number of sticks, and indications were recorded. The presence of pneumoperitoneum on the initial chest film was considered to be a positive finding. After a positive result, a repeat chest film was obtained 72 hours later to determine whether there was progression or resolution of the free air. Patients enrolled in the study were also monitored clinically for evidence of peritonitis.

MAIN OUTCOME

Of the 65 patients who underwent PEG placement, 13 developed a pneumoperitoneum on the initial chest radiograph; there was complete resolution of pneumoperitoneum at 72 hours in 10 of the 13 patients. In 3 patients, the free air persisted but was of no clinical significance.

MEASUREMENTS

The free air was quantified by measuring the height of the air column under the diaphragm and was graded with a scoring system (0, no air; 1, small; 2, moderate; 3, large).

RESULTS

Eleven patients who underwent PEG died during the hospitalization; none of the deaths were related to the PEG placement or pneumoperitoneum. The other 54 patients were discharged to a skilled nursing facility. No patients in the study had clinical evidence of peritonitis. There were no adverse events, ie, infection or bleeding, associated with the PEG placement in any of the patients.

CONCLUSIONS

Our data suggest that pneumoperitoneum after PEG placement is common and, in the absence of clinical symptoms, is of no clinical significance and does not warrant any further intervention.

Benign pneumoperitoneum after colonoscopy: a prospective pilot study

Benign pneumoperitoneum is asymptomatic free intraabdominal air and is reported to occur occasionally with colonoscopy. Management of benign pneumoperitoneum after colonoscopy is controversial and may depend on incidence or etiology. No previous studies prospectively investigated the incidence or inciting factors of benign pneumoperitoneum resulting from colonoscopy. In this study, 100 patients underwent colonoscopy and then radiography of the chest and abdomen to detect free air. The average age was 58 +/- 6.2 years, and 48 of the colonoscopies were therapeutic. No cases of benign pneumoperitoneum were detected, estimating the incidence at 0% to 3% for diagnostic and therapeutic colonoscopy. These data indicate that benign pneumoperitoneum attributable to colonoscopy is rare and possibly nonexistent. Given the paucity of data favoring the occurrence of benign pneumoperitoneum after colonoscopy, we advocate treating all cases of free intraabdominal air after colonoscopy as perforations.

Evaluation of risk factors for mortality in perforated peptic ulcer in Ankara Numune Teaching Hospital, Ankara, Turkey

OBJECTIVE

To assess the risk factor that influence mortality from perforated peptic ulcer.

DESIGN

Retrospective study.

SETTING

Ankara Numune Teaching and Research Hospital, Ankara, Turkey.

SUBJECTS

A total of 342 patients with perforated peptic ulcer disease were identified from April 1997 to January 2004. Data for the patients were extracted from the hospital records, operative notes and clinic charts.

MAIN OUTCOME MEASURES

Age, sex, coexisting medical illness, use of non-steroidal anti-inflammatory drugs (NSAID) or steroids, preoperative shock, delay in treatment location of ulcer size, type of operation time, albumin concentration postoperative complications, postoperative hospitals stay and mortality results for all patients were obtained.

RESULTS

Patients were aged from 17 to 80 years (mean 63 years, median 68 years) there were 210 males and 132 females. The mortality rate was 8.8% (30/342), and 62 patients had postoperative complications. Multivariate analysis showed that co-existing medical illness, preoperative shock, delay in treatment and low albumin concentrations were independent risk factors that significantly contributed to mortality.

CONCLUSION

This study confirms co-existing medical illness, preoperative shock, delay in treatment and low albumin concentration as significant risk factors that increase mortality in patients with perforated peptic ulcers. These factors could serve as a guide to opine the risk and to improve the outcome in patients with perforated peptic ulcer. Mortality could be reduced by preventing delay in diagnosis and treatment for any co-existing medical illness and providing appropriate nutrition support.

Postoperative pneumoperitoneum: prevalence, duration, and possible significance

Free intraperitoneal air after abdominal surgery is a confounding finding with uncertain significance. A diagnostic dilemma often arises as to its origin: does it merely represent residual postoperative pneumoperitoneum (PP), which will need no intervention, or does it indicate a complication such as an anastomotic leak or a perforation of the gastrointestinal tract. Residual PP is usually well tolerated, as it will be absorbed over time and requires no therapy. On the other hand, air escaping through a gastrointestinal tract perforation or leak usually represents an intra-abdominal catastrophe requiring urgent intervention. This intriguing subject has been dealt with quite extensively based on plain film radiography findings in the past 50 years, and has lately also been studied on CT. This review discusses factors influencing the prevalence of PP and its range of duration.

Duration of pneumoperitoneum on chest radiograph after open colorectal surgery

BACKGROUND

Postoperative pneumoperitoneum on a plain chest radiograph is a potentially important medicolegal document of possible complication. However, pneumoperitoneum may be observed without significance after intra-abdominal procedures.

METHODS

Between April 2001 and March 2002, 204 consecutive open laparotomies for colorectal surgery were studied. Sixty-three patients had 97 chest radiographs taken before the twenty-fifth postoperative day.

RESULTS

Only one patient had subdiaphragmatic air (height >20 mm) on the tenth postoperative day associated with a visceral perforation. Normal subdiaphragmatic pneumoperitoneum was observed on 11 films in 8 patients (13%). Small amounts of air (<15 mm high) were observed in 7 (15%) of 47 radiographs on days 0-5, in 4 (18%) of 25 radiographs on days 6-10, but in no radiograph of 24 after day 10.

CONCLUSIONS

Subdiaphragmatic pneumoperitoneum less than 20 mm high is often observed between the sixth and tenth postoperative days, without clinical importance.

Management of peritoneal tear during endoscopic extraperitoneal inguinal hernioplasty

BACKGROUND

Peritoneal tear during endoscopic extraperitoneal inguinal hernioplasty (TEP) results in pneumoperitoneum and loss of extraperitoneal space. To avoid bowel adhesions, internal herniation, and mesh migration, closure of the peritoneal opening is preferred. The present study was conducted to evaluate the efficacy of various operative techniques for the closure of peritoneal laceration.

METHODS

Between April 2000 and May 2001, 100 consecutive patients undergoing 123 TEPs were recruited for the present study. The incidence of peritoneal tear and techniques for the closure of peritoneal opening were documented. Operative time and postoperative morbidity were compared among groups for which different closure methods of peritoneal laceration were used.

RESULTS

The incidence of peritoneal tear was 47%. The mean operative times of unilateral TEPs with and without peritoneal laceration were 66 min and 53 min, respectively (p<0.05). Techniques for the closure of the peritoneal opening included endoscopic stapling (n = 12), endoscopic suturing (n = 14), and pretied suture loop ligation (n = 21). The mean operative times for unilateral TEPs with endoscopic stapling, pretied suture loop ligation, and endoscopic suturing of peritoneal tear were 53, 64, and 82 min, respectively (p<0.05). Comparison of postoperative morbidity showed no significant differences among the three groups.

CONCLUSION

Peritoneal tear is a frequent and challenging intraoperative event during TEP. Its occurrence significantly prolongs the length of operation. Endoscopic stapling and pretied suture loop ligation are safe and quick techniques for the closure of peritoneal tear during TEP.

The incidence and significance of free air after percutaneous endoscopic gastrostomy

Percutaneous endoscopic gastrostomy (PEG) is well established as a safe and effective means of providing enteral feeding access in patients unable to tolerate oral feeding. There is some question, however, as to the true incidence of free air after PEG and the clinical significance of free air in these patients. We report our experience with 119 patients over 4 years who underwent placement of a percutaneous gastrostomy tube. This study is a retrospective review of percutaneous endoscopic gastrostomies performed by the Critical Care Service for Surgery (CCSS). A database of percutaneous endoscopic gastrostomies performed by the CCSS was maintained from September 1997 through December 2001. Complications of percutaneous gastrostomies were added to the database when noted. The electronic medical record of all patients was reviewed for the results of radiographic studies. Prior abdominal operations were noted as well as gastrostomy tube complications and outcome. A total of 115 intensive care unit patients underwent PEG placement by the CCSS. This total includes 18 patients who had undergone prior upper abdominal surgery, Three additional patients who underwent placement of a gastrostomy tube by vascular interventional radiology and one patient who underwent PEG placement by the ear, nose, and throat service were brought to the attention of CCSS secondary to complications for a total of 119 patients. Only four patients (3.4%) were found to have free air on subsequent chest radiograph. Six patients (5.2%) were found to have free air on abdominal CT scans. Two patients with free air on CT underwent exploratory celiotomy as a result of additional signs of peritonitis. Both were negative explorations. The incidence of free air after PEG in our experience is significantly less than the incidence in previous studies. In patients with free air after PEG placement exploratory celiotomy is not indicated in the absence of other clinical findings of peritonitis. Additionally it was noted that PEG placement could safely be performed in patients with prior upper abdominal surgery with a low incidence of complications.

Pneumatosis intestinalis in non-neonatal pediatric patients

OBJECTIVES

To describe fully pneumatosis intestinalis (PI) in non-neonatal pediatric patients and to characterize those patients with higher risk of poor outcome, including need for surgery and death.

METHODS

A retrospective chart review was conducted of all patients 30 days of age and older with PI in a tertiary care children's hospital during an 8-year period. Underlying medical condition, presenting signs and symptoms, radiologic grade of pneumatosis, and events that immediately preceded the onset of PI were reviewed, and their correlation with outcome was assessed.

RESULTS

Thirty-seven episodes of PI occurred in 32 patients. Seventy-eight percent of patients were male, and the median age was 29 months. Major patient diagnostic groups identified with PI included healthy children (22%), patients with organ and bone marrow transplant (22%), patients with decompensated congenital heart disease (12.5%), motility disorders (12.5%), gastroschisis (9%), and short bowel syndrome (6%). The most common events that immediately preceded the onset of PI were noninfectious colitis (32%), acute enteric infection or toxin (27%), bowel ischemia (20%), and gastrointestinal dysmotility (17%). Resolution of PI with medical management occurred in 78% of episodes (good outcome). Twenty-two percent of episodes resulted in a poor outcome: patient death (8%) or surgery (14%). The presence of portal venous gas and low mean serum bicarbonate concentration were the only clinical factors that correlated significantly with poor outcome. Only 25% of patients with pneumoperitoneum required surgery. Poor outcome was seen most commonly in 2 patient diagnostic groups: transplant patients (43% of patients) and decompensated cardiac disease (50% of patients). The event that preceded PI also had an impact on outcome. PI preceded by ischemia or graft versus host disease colitis was associated with poor outcome in 50% and 75% of cases, respectively.

CONCLUSIONS

PI is a radiologic sign that occurs in a variety of settings in non-neonates. PI preceded by bowel ischemia or graft versus host disease colitis has the worst prognosis, and the presence of portal venous gas and acidosis correlate with poor outcome. Not all patients with pneumoperitoneum require surgical intervention. Overall, outcome of PI in non-neonatal patients was better than that reported in neonates with necrotizing enterocolitis.pneumatosis intestinalis, necrotizing enterocolitis, non-neonatal.

Pneumoperitoneum: a review of nonsurgical causes

OBJECTIVE

To review causes of nonsurgical pneumoperitoneum (NSP), identify nonsurgical etiologies, and guide conservative management where appropriate.

DATA SOURCE

We conducted a computerized MEDLINE database search from 1970 to 1999 by using key words pneumoperitoneum and benign, nonsurgical, spontaneous, iatrogenic, barotrauma, pneumatosis, diaphragmatic defects, free air, mechanical ventilation, gynecologic, and pelvic. We identified 482 articles by using these keywords and reviewed all articles. Additional articles were identified and selectively reviewed by using key words laparotomy, laparoscopy, and complications.

STUDY SELECTION

We reviewed all case reports and reviews of NSP, defined as pneumoperitoneum that was successfully managed by observation and supportive care alone or that required a nondiagnostic laparotomy.

DATA SYNTHESIS

Each unique cause of nonsurgical pneumoperitoneum was recorded. When available, data on nondiagnostic exploratory laparotomies were noted. Case reports were organized by route of introduction of air into the abdominal cavity: abdominal, thoracic, gynecologic, and idiopathic.

CONCLUSIONS

Most cases of NSP occurred as a procedural complication or as a complication of medical intervention. The most common abdominal etiology of NSP was retained postoperative air (prevalence 25% to 60%). NSP occurred frequently after peritoneal dialysis catheter placement (prevalence 10% to 34%) and after gastrointestinal endoscopic procedures (prevalence 0.3% to 25%, varying by procedure). The most common thoracic causes included mechanical ventilation, cardiopulmonary resuscitation, and pneumothorax. One hundred ninety-six case reports of NSP were recorded, of which 45 involved surgical exploration without evidence of perforated viscus. The clinician should maintain a high index of suspicion for nonsurgical causes of pneumoperitoneum and should recognize that conservative management may be indicated in many cases.

Incidence and significance of subdiaphragmatic air following laparoscopic cholecystectomy

Subdiaphragmatic free-air may be indicative of a perforated viscus; however, it is normally present after open abdominal surgery. The objective of this study was to determine the significance and incidence of subdiaphragmatic free air following laparoscopic cholecystectomy (LC). Cases of intestinal perforation following laparoscopic cholecystectomy from 1991 to 1995 at The University of Texas Health Science Center at San Antonio were reviewed and their association with subdiaphragmatic free air was determined. Twenty-five patients undergoing LC and 20 patients undergoing open cholecystectomy (OC) were prospectively evaluated with chest radiographs to determine the incidence and quantity of nonpathologic postoperative free air. Four cases of intestinal perforation resulting from trocar injuries or electrocautery burns occurred among 1603 LCs during this study period, for an incidence of 0.2 per cent. Three of the four patients with perforations were diagnosed postoperatively (2-5 days), and two patients had a moderate volume of subdiaphragmatic free air that aided the diagnosis. The incidence of subdiaphragmatic air following LC was 24 per cent, compared to 60 per cent for OC (P < 0.05). Eighty-three per cent of patients with retained air after LC had a minimal volume, compared to 67 per cent of patients after OC (P < 0.05). Nonpathologic subdiaphragmatic free air may normally be present following laparoscopic cholecystectomy but is uncommon 24 hours after the operation. When present, only a small volume is usually detectable. In the rare situation of intestinal perforation resulting from LC, subdiaphragmatic free air may be an important diagnostic finding.

A review of computerized tomography in blunt abdominal trauma at Christchurch Hospital

A review was undertaken of computerized tomography (CT) of the abdomen, performed between March 1993 and December 1994 for blunt abdominal trauma at Christchurch Hospital. CT findings were correlated with the clinical outcome. The outcome was either recovery from an abdominal point of view with or without laparotomy, or postmortem. A total of 116 CTs were reviewed, of which 76 were abnormal. CT was highly sensitive and specific for a variety of abdominal traumatic lesions. There were 1 false positive and 4 false negatives (only 2 of these significant). There was 1 non-therapeutic laparotomy based on CT findings. There was only 1 case of delayed treatment based on CT results. Three patients had unexplained findings of pneumoperitoneum. Care should be taken when interpreting the presence of free intraperitoneal air on CT scan. The possibility of missed bowel perforation should be considered, especially in the presence of free intra-abdominal fluid and no solid organ injury to account for it. CT scans are useful in the conservative management of solid organ injuries.

Pneumoperitoneum in peritoneal dialysis patients

There has been recent controversy regarding the clinical significance of pneumoperitoneum in patients undergoing peritoneal dialysis. The incidence of pneumoperitoneum has been estimated to be 21.2% to 33.7% in prior studies of peritoneal dialysis patients. Of the peritoneal dialysis patients with pneumoperitoneum, only a small percentage (5.9% to 14.3%) had documented visceral perforations. The controversy arises in that anywhere from 20% to 100% of peritoneal dialysis patients with pneumoperitoneum and peritonitis had visceral perforation, and 32.4% to 57.1% of chronic ambulatory peritoneal dialysis patients had asymptomatic pneumoperitoneum of unknown etiology. These disparate incidences made clinical interpretation of pneumoperitoneum difficult. In addition, prior study result disagreed as to the usefulness of the extent of pneumoperitoneum in predicting visceral perforation. We retrospectively reviewed 694 chest x-ray film and acute abdominal series reports from 1982 to 1993 in 75 peritoneal dialysis patients, with 9.3 +/- 1.3 (mean +/- SEM) x-ray films per patient. The reports were confirmed by reviewing 363 x-ray films (52%). Eight patients (10.7%) had 10 episodes of pneumoperitoneum. Six of these eight patients had asymptomatic pneumoperitoneum from a known etiology: four had undergone abdominal surgery for catheter placement the prior week and two had catheter manipulation immediately preceding the x-ray. One patient had three episodes of pneumoperitoneum: one after catheter placement and two not associated with a known etiology for pneumoperitoneum while on the cycler. One patient had a surgically confirmed colonic perforation with a large pneumoperitoneum and peritonitis.(ABSTRACT TRUNCATED AT 250 WORDS)

Pneumoperitoneum after laparoscopic cholecystectomy: frequency and duration as seen on upright chest radiographs

OBJECTIVE

This study aimed to determine the frequency and duration of pneumoperitoneum after laparoscopic cholecystectomy, as detected on upright chest radiographs.

MATERIALS AND METHODS

Fifty-five patients who underwent laparoscopic cholecystectomy were studied prospectively. Upright posteroanterior chest radiographs were obtained 6 hr after surgery (day 1); additional radiographs were obtained on days 2, 4, 7, and 14, if required, until the pneumoperitoneum resolved. A perpendicular measurement of any pneumoperitoneum detected between the diaphragm and the liver was obtained. The pneumoperitoneum was graded as absent, trace (1-5 mm), mild (6-10 mm), or moderate (10-15 mm).

RESULTS

No evidence of pneumoperitoneum was seen on chest radiographs taken 6 hr after surgery (day 1) in 27 (54%) of the 50 patients who completed the study. Of the remaining 23 patients (46%), all but one showed resolution of the pneumoperitoneum in the first week. Of these 23 patients, 17 showed trace pneumoperitoneum and six showed mild pneumoperitoneum on chest radiographs.

CONCLUSION

Despite the use of carbon dioxide gas during laparoscopic cholecystectomy, a significant number of patients have postsurgery pneumoperitoneum that is visible on upright chest radiographs. The pneumoperitoneum resolves in most patients within the first week after surgery.

Incidence and significance of pneumoperitoneum in continuous ambulatory peritoneal dialysis

In a retrospective study we reviewed upright chest x-ray films of 101 continuous ambulatory peritoneal dialysis (CAPD) patients to determine the incidence and significance of free subdiaphragmal air. A pneumoperitoneum (PP) was diagnosed if a minimal shadow of free air was detected under the diaphragm. The amount of free air was determined by measuring the height and width of the subdiaphragmal air shadow. Of all CAPD patients, 33.6% (34 of 101) had at least one occurrence of PP. Thirteen of these 34 patients (38.2%) were diagnosed within 30 days after catheter implantation, 10 patients (29.5%) acquired a PP during an episode of peritonitis, and in 11 patients (32.4%) no additional risk factor could be determined. Patients radiographed within 30 days after catheter implantation showed a statistically significant higher incidence of PP compared with the same patients radiographed later (22% v 10%; P < 0.05). The incidence of PP in CAPD patients suffering from peritonitis (33%) was significantly higher than in patients without peritonitis (10%; P < 0.001). The amount of free air did not differ statistically significantly between the investigated groups. Only two patients with PP and peritonitis had surgically confirmed visceral perforation. Therefore, the main reason for PP seemed to be handling faults during CAPD bag exchange. There was no correlation between the organisms causing peritonitis and PP or the CAPD connector system and PP. In conclusion, a PP occurs in approximately one third of all CAPD patients and a visceral perforation cannot be diagnosed by the occurrence and amount of free subdiaphragmal air.

Pneumoperitoneum following percutaneous endoscopic gastrostomy. Does the timing of panendoscopy matter?

Percutaneous endoscopic gastrostomy (PEG) has had a significant impact on enteral alimentation in patients unable to maintain adequate oral caloric intake. PEG avoids the morbidity and mortality associated with the traditional feeding gastrostomies placed by celiotomy. Several authors have documented benign, self-limiting pneumoperitoneum following PEG placement. No study has addressed whether the timing of panendoscopy in relation to gastric puncture has an effect on the incidence of post-PEG pneumoperitoneum. The authors prospectively studied 30 patients undergoing PEG. Panendoscopy was either performed before or after gastric puncture, and each patient then had abdominal radiographs to determine the presence of pneumoperitoneum. Four of 16 patients (25%) having panendoscopy prior to gastric puncture had radiographic evidence of pneumoperitoneum compared to three of 14 patients (23%) having panendoscopy following gastric puncture. The authors conclude that the timing of panendoscopy in relation to gastric puncture does not significantly effect the incidence of post-PEG pneumoperitoneum.

[The diagnostic value of the plain abdominal radiogram in differentiating rotavirus-negative and rotavirus-positive necrotizing enterocolitis]

Clinical data and radiographic findings of 32 newborn suffering from necrotising enterocolitis were analysed [12 patients with rotavirus-positive necrotising enterocolitis (RV + NEC), 20 patients with rotavirus-negative necrotising enterocolitis (RV-NEC)]. The presence and degree of pneumatosis intestinalis, portal venous gas and pneumoperitoneum on abdominal radiographs were graded after Kosloske et al. according to "mild, moderate, and severe". Pneumatosis intestinalis occurred twice as often in the ascending colon in RV-NEC compared to RV + NEC, whereas the transverse colon was involved nearly as frequently as the descending colon in both groups. Portal venous gas was present in 10% of the cases with RV-NEC and was absent in RV + NEC. Pneumoperitoneum only occurred in 8% of RV + NEC but in 20% of RV-NEC. Radiographic findings are helpful in the differentiation between both groups of NEC. Conservative therapy is preferable especially in mainly distal colon distribution of pneumatosis intestinalis without pneumoperitoneum.

Traumatic pneumoperitoneum. Implications of computed tomography diagnosis

Pneumoperitoneum detected on plain radiographs following blunt abdominal trauma is nearly pathognomonic of bowel perforation and usually mandates exploratory laparotomy. To determine the significance of computed tomography (CT)-detected pneumoperitoneum, we reviewed the clinical records and imaging studies of all trauma patients in our hospital over a seven-year period whose abdominal CT scans showed free intraperitoneal gas. Patients who had penetrating injuries or peritoneal lavage prior to CT were excluded. Of the 18 patients who met these inclusion criteria, surgically confirmed bowel injury was found in only four (22%). In the remaining 14 patients, no evidence of gastrointestinal perforation was found by exploratory laparotomy (2 patients), diagnostic peritoneal lavage (4 patients), GI studies and clinical follow-up (6 patients), or clinical follow-up alone (5 patients). Seven patients had a pneumothorax as a possible cause for pneumoperitoneum. Two additional patients were on mechanical ventilation. Unlike pneumoperitoneum seen on plain film, CT-detected pneumoperitoneum is not pathognomonic of bowel perforation. While laparotomy is not mandatory in the non-surgically explored patient, close clinical observation is essential, and additional diagnostic tests such as peritoneal lavage or radiographic contrast studies can be beneficial to confirm the absence of intestinal injury.

Incidence and significance of pneumoperitoneum after inguinal herniorrhaphy

Previous studies have shown pneumoperitoneum either to be extremely rare or to not occur after inguinal herniorrhaphy, and that its presence signifies a serious intra-abdominal complication. A prospective study has been carried out to consider the incidence and significance of pneumoperitoneum after herniorrhaphy for indirect inguinal hernias. In a 1-year period, 100 patients were studied. Pneumoperitoneum was detected in six patients. In five patients, the amount of free gas was minimal and was reabsorbed after 48 h. The pneumoperitoneum was large and of increasing amount in one patient. Faecal fistula developed 7 days after operation due to an injury from the hernial repair to the sigmoid colon. The result of this study suggested that detectable pneumoperitoneum of small amount may be present after inguinal herniorrhaphy and, if it persists for longer than 48 h, the presence of a perforated viscus should be considered.

[Postoperative pneumoperitoneum. Incidence, significance, duration]

The phenomenon of post-operative pneumoperitoneum is considered and its formation modalities, incidence, site and duration evaluated. The phenomenon is related to the constitution of the patient and the extent of the operation performed. Differences between post-operative and perforation forms are pointed out.