Signs to Know That My Vp Shunt Is Working Again
Ventriculoperitoneal shunt block: what are the best predictive clinical indicators?
Abstract
Aims: To evaluate the predictive value of symptoms, signs, and radiographic findings accompanying presumed ventriculoperitoneal (VP) shunt malfunction, past comparison presentation with operative findings and subsequent clinical grade.
Methods: Prospective study of all 53 patient referrals to a paediatric neurosurgical eye betwixt April and Nov 1999 with a diagnosis of presumed shunt malfunction. Referral pattern, presenting symptoms and signs, results of computed tomography (CT) scanning, operative findings, and clinical event were recorded. Two patient groups were defined, one with proven shunt cake, the other with presumed normal shunt function. Symptomatology, CT scan findings, and the subsequent clinical course for each grouping were then compared.
Results: Common presenting features were headache, drowsiness, and vomiting. CT scans were performed in all patients. Thirty vii had operatively proven shunt malfunction, of whom 34 had shunt block and three shunt infection; 84% with shunt block had increased ventricle size when compared with previous imaging. For the two patient groups (with and without shunt block), odds ratios with 95% conviction intervals on their presenting symptoms were headache 1.v (0.27 to ten.9), vomiting 0.9 (0.25 to iii.65), drowsiness 10 (0.69 to 10.7), and fever 0.19 (0.03 to 6.95). Every patient with ventricular enlargement greater than their known baseline had a proven blocked shunt.
Conclusions: Drowsiness is by far the best clinical predictor of VP shunt cake. Headache and airsickness were less predictive of acute shunt block in this study. Wherever possible CT scan findings should be interpreted in the context of previous imaging. Nosotros would caution that non all cases of proven shunt blockage present with an increase in ventricle size.
- hydrocephalus
- shunt blockage
- ventriculoperitoneal shunt
- CSF, cerebrospinal fluid
- CT, computed tomography
- GCS, Glasgow coma scale
- VP, ventriculoperitoneal
Statistics from Altmetric.com
- hydrocephalus
- shunt blockage
- ventriculoperitoneal shunt
- CSF, cerebrospinal fluid
- CT, computed tomography
- GCS, Glasgow coma scale
- VP, ventriculoperitoneal
Cerebrospinal fluid (CSF) shunts remain the mainstay of treatment for most cases of hydrocephalus in the paediatric population. All are prone to malfunction, with block being the commonest reported complexity in about series. In the largest reported cohort of 1719 patients, 56% experienced at to the lowest degree one episode of shunt block in the 12 years following insertion.1 Similarly, Lazareff and colleagues2 recently reported a 44% prevalence of shunt malfunction, including block, in 244 children with CSF shunts followed up over a flow of up to six years mail service initial insertion. The superlative "danger" menstruation for blockage is in the kickoff year subsequently insertion, with rates every bit high as 20% recorded in some series.three Annual rates of shunt blockage have been estimated by Rekate to be approximately 5%.4 These findings are in keeping with our published unit of measurement experience in which we noted a 28% incidence of shunt cake over a 10 twelvemonth flow, and that 55% of patients experienced at least i episode of shunt malfunction during this time.v
The presentation of shunt block may undoubtedly be with what might be termed "classical" symptoms, namely headache, vomiting, and drowsiness,vi or may on occasion be more than atypical and misleading.7 Documented more atypical presentations include seizures, intestinal pseudocyst, syringomyelia, cranial nervus palsies, and hemiparesis.6 Parkinson similar rigidity,6 visual failure,viii and developmental standstill have also been documented.
The importance of prompt diagnosis and operative handling of blocked ventriculoperitoneal (VP) shunts cannot be overemphasised. Death or major neurological sequelae, including blindness, are well described sequelae of delayed treatment.5 Difficulty in making the diagnosis may stem from a considerable symptom overlap with other common childhood illnesses. This is compounded further by the fact that an accurate first manus history may not show forthcoming, as a event either of patient age, or that up to threescore% attend special school and and so a first hand history may not be possible.v, 9, 10
We present a blinded prospective written report in which we evaluate which symptoms unremarkably prompting an urgent neurosurgical opinion are truly predictive of acute shunt cake. This is further correlated with the results of computed tomography (CT) scanning in each patient and ultimate clinical outcome.
METHODS
Setting
The department of neurosurgery at Slap-up Ormond Street Hospital provides tertiary level paediatric neurosurgical care to a big part of London and southeast England. The unit carries out approximately seventy operative procedures per twelvemonth on patients with newly diagnosed hydrocephalus or related conditions, with the workload divided every bit betwixt three consultant neurosurgeons. Once shunted, patients are followed upwards in a paediatric neurosurgical clinic, and an try made to larn a baseline CT scan postoperatively on all patients. They are additionally offered "open up door" access to the unit should they develop symptoms suggestive of a shunt cake. These symptoms are detailed in an information booklet given to every parent once a shunt has been inserted.
Patients
The study menstruum was from April to Nov 1999. All children referred to the Department of Neurosurgery at Swell Ormond Street Infirmary with a tentative diagnosis of shunt malfunction were entered into the study. Fifty three such admissions were recorded over this period. These comprised 34 patients, 11 of whom were seen on more than one occasion.
Definitions
The diagnosis of shunt blockage was considered confirmed when peroperative test revealed no CSF flow from the ventricular catheter, or when manometric evaluation revealed abnormal or no flow through the valve or distal catheter. The diagnosis of "no shunt blockage", which resulted in no surgical intervention, was considered confirmed if the patient fabricated the recovery anticipated from their alternative diagnosis and did not re-present with further symptoms and signs suggesting shunt malfunction.
Data collection
This was a prospective study. None of the surgeons were aware the information was being collected during the fourth dimension period it was carried out. Table ane illustrates the data recorded on each of the 53 occasions patients were admitted during the study period.
View this tabular array:
- View inline
Table 1
Data recorded on each patient admission referred with possible VP shunt malfunction over the study period
Statistical analysis
Four patient access groups were initially defined:
All admissions referred with suspected shunt block/malfunction (n = 53)
Those admissions nosotros diagnosed preoperatively as having shunt block/malfunction, group B1 (northward = 37); and those nosotros diagnosed equally non having shunt block/malfunction, grouping B2 (n = 16)
Admissions with confirmed shunt block (n = 34) or shunt infection (due north = 3)
Admissions with an initially incorrect clinical diagnosis of "normal shunt part" who afterwards re-presented during the study catamenia with proven cake (n = 4).
Surgical proof of shunt blockage was required for inclusion in group C. Odds ratios were then calculated to compare the symptomatology betwixt groups C and B2. In this way nosotros compared the presenting symptomatology in those referred with proven shunt malfunction (group C) with those in whom we considered shunt role to be normal on access (group B2). Ratios were calculated for headache, vomiting, drowsiness, and fever. The low incidence of other presenting symptoms negated against meaningful statistical analysis equally to their significance. Odds ratios were and then recalculated with the admissions from group D transferred to grouping C. By this process symptomatology was compared between 2 groups; those with proven shunt malfunction, and those with proven normal shunt office.
RESULTS
Patient age ranged from 6 weeks to 17.7 years of historic period, median 7.ii years. Table ii summarises the aetiology of hydrocephalus in this cohort.
View this tabular array:
- View inline
Table 2
Aetiology of hydrocephalus
Referral pattern
Xl of the 53 admissions were referred direct by their parents every bit per the unit "open up door" policy. A further ten came from outlying district general hospitals. Ii were admitted directly from clinic at Great Ormond Street Hospital. Ane was transferred in by air ambulance from abroad. In 39 of the 53 admissions during this study menstruation, the patients involved had suffered a previous episode of shunt malfunction necessitating revision. One patient was admitted on seven occasions during the study period, necessitating five shunt revisions in full. Thirty four private patients were seen during the written report period. Table iii illustrates the presenting symptoms and the results of CT scanning in each patient admission (53 admissions of 34 individual patients).
View this table:
- View inline
Table 3
Presenting symptoms in each case, with the results of CT scanning
On eleven occasions patients were unable to vocalise their symptomatology on admission. Reasons for such included young age, obtundation on access, and longstanding learning disability.
Surgery was undertaken for 37 of the 53 admissions for a preoperative diagnosis of shunt blockage in 34 and for shunt infection in three. This resulted in resolution of the presenting symptoms in all 34 children with blocked shunts, 84% of whom had increased ventricle size noted on their preoperative CT scanning when admission images were compared with those on file. In the other three operations an infected shunt was removed and replaced with an external ventricular drain. All 3 had a farther ventriculoperitoneal shunt reinserted post-obit intrathecal and intravenous antibody therapy.
Of the remaining 16 admissions, alternative diagnoses were proven in 5 cases. These comprised viral illness (two admissions) and CSF overdrainage (three). For the other eleven admissions, no identifiable unifying diagnosis was apparent. In four of these cases (group D), the patients re-presented inside the study period and were later found to take shunt block. In all four shunt revision resulted in symptom resolution. On first presentation none of these 4 patients had a Glasgow coma scale (GCS) less than 15 or evidence of a contempo increment in ventricle size on CT scanning. Symptoms on their kickoff access comprised headache or vomiting, or both. On re-presentation, symptomatology was different in each case. Three of the 4 had a Glasgow coma scale less than fifteen, and 2 had increased ventricle size on CT scanning. The patients who accounted for the other seven admissions for which no specific diagnosis was made did not re-present during the study menses with shunt malfunction.
Statistical analysis
For admissions with and without shunt malfunction, groups C and B2 respectively, the odds ratios with 95% confidence intervals for comparison of the symptomatology were headache ane.5 (0.27 to ten.ix), airsickness 0.9 (0.25 to 3.65), drowsiness 10 (0.69 to 10.7), and fever 0.ii (0.03 to 6.95). The equivalent odds ratio for enlarged ventricle size on CT scanning was space, equally every admission with ventricular enlargement greater than their previous baseline had a proven blocked shunt, in contrast to the admission group "without shunt block" (group B2), in which ventricular size was uniformly unchanged. In the presence of headache, vomiting, and drowsiness, simply no fever, 82% of admissions were later proven to take astute shunt cake. A further half-dozen% (three cases) had an infected VP shunt (admissions 5, 47, and 48 in table three). In only one instance was fever an initial presenting sign. All iii presented with airsickness and drowsiness; one presented with headache.
If the four admissions (group D) originally considered to have normal shunt function are instead included in the "shunt malfunction group" (group C) (every bit their initial presentation likely represented shunt block), and the odds ratios for symptomatology in each recalculated, the results are equally follows: drowsiness 4.8, headache two.5, vomiting 1.3, fever 0.1.
Eight of the x admissions referred via their commune general hospital subsequently had proven shunt block, compared with 24 of 40 (threescore%) seen every bit a result of the "open door policy". The four admissions initially incorrectly considered to have normal shunt role had all presented straight to the unit of measurement via the open door policy.
Word
This cohort illustrates the broad aetiology of hydrocephalus. Many afflicted have other medical bug and most are looked after by a multidisciplinary squad. Equally a result, the paediatrician working in the district general hospital setting is not infrequently faced with the question "Is this shunt blocked?".
The results of this study signal that the presence of headache, airsickness, and drowsiness together make it very likely that an affected patient has shunt dysfunction; in most cases this volition mean acute shunt block. A minority will have an infected shunt, though in the absence of fever this study shows at that place is piddling to easily clinically distinguish between shunt infection and block. The calculated odds ratios for symptomatology illustrate the striking positive relation betwixt drowsiness and acute shunt cake. It is this sign in particular that should prompt urgent neurosurgical referral. Headache or vomiting in isolation is less predictive of astute block, and though one should adopt a low threshold for seeking a neurosurgical stance, a careful search for an alternative diagnosis is warranted. Recent reported figureshalf dozen, 11 for symptomatology in proven shunt malfunction (which includes infection in some cases) are headache (47–55% of cases), vomiting (40–ninety%), and drowsiness (xxx–60%). Relatively comparable figures from this study, which focuses on shunt block equally opposed to all causes of malfunction, are headache 74%, vomiting 73%, and drowsiness 73%.
We are realistic that eliciting a history in this setting may sometimes prove difficult5, 9, x and justify early neurosurgical advice, just the results of this study are encouraging, with a low false positive charge per unit (20%) of referral from district full general hospitals. Furthermore, they are in keeping with previous published studies.11 This includes the recorded 5% incidence of overdrainage symptoms,five a status probably underestimated past hospital access rates.
During the fourth dimension period of this report, in a minority of cases (northward = 4), an incorrect diagnosis of presumed normal shunt office was made when each initially presented. In none of the four on first presentation was drowsiness a presenting feature. Following discharge each later re-presented during the study period with a dissimilar symptom profile, which included drowsiness in three cases. All four were institute to have operatively proven shunt block. In each no discernible neurological morbidity was apparent as a consequence. The "recalculated" odds ratios show a nigh identical trend in symptom significance, and again highlight drowsiness as an of import positive predictive clinical sign of shunt block.
The limitations of performing CT scanning without the facility to compare with previous images are well illustrated, as are the pitfalls of over reliance on scan findings. However, the observation that in 16% of admissions the CT scans were unhelpful should non detract from the fact that in 84% the diagnosis was effectively confirmed by an increase in ventricle size when compared with the most recent previous CT examination. Given the importance of arriving swiftly at an authentic diagnosis, we would recommend that all children have a baseline CT study performed a few weeks after either their initial shunt insertion or a shunt revision. Paediatric units with the facility to bear out scans on children with suspected shunt blockage should hold copies of these images, as should, of grade, the regional neurosurgical unit. In some situations, particularly when a family is moving from place to place, it may exist sensible for copies to besides exist held past the child'due south carers. This may prove an invaluable arrangement for those (often nocturnal) situations when the radiology department is unable to locate a patient's previous studies.
The importance of paying careful attention to the observations of the kid's parents and other carers, specially if they take had feel of shunt cake in the past, cannot exist overemphasised. In a previous study11 (which excluded children who had had recent shunt problems) we showed that families were at least as accurate as paediatricians in diagnosing shunt block. Indeed, information technology is the neurosurgeons who may be reviewing a child perchance only once a year (or who may have delegated follow upward completely to a local paediatric department12), who may have the least knowledge of the kid'south "regular" country of health, complicated by a variety of disabilities.
Key messages
-
Always doubtable shunt malfunction in a child with a shunt and no alternative convincing explanation for their symptoms
-
Be particularly suspicious if drowsiness is a prominent symptom in shunted patients
-
In trying to interpret a child'south presenting symptoms, ever defer to the feel of the family if the child has had previous shunt block
-
When in dubiousness ever hash out with a tertiary centre
-
All patients should accept a CT scan performed equally a routine at some stage after a primary shunt insertion or revision procedure, and a copy held at non only the tertiary middle but also at the local district full general hospital if it has a CT scanning facility
-
An increase in ventricle size is highly suggestive of shunt blockage, but no alter, particularly if the ventricles are slit like, does non rule information technology out
Conclusions
Information technology is well documented that the presentation of astute shunt block is heterogeneous. Furthermore, there is a significant morbidity and mortality in belatedly diagnosis. In conclusion, this study illustrates the importance of considering shunt malfunction in a child with a shunt and no culling disarming explanation for their symptoms, specially if drowsiness is a prominent feature. In trying to interpret a kid's presenting symptoms, always defer to the experience of the family if the child has had previous shunt block, and if in doubtfulness, ever discuss with a 3rd heart. An increment in ventricle size is highly suggestive of shunt blockage, but no modify in size, particularly if the ventricles are slit like, does not dominion it out.
REFERENCES
- ↵
- ↵
- ↵
- ↵
- ↵
- ↵
- ↵
- ↵
- ↵
- ↵
- ↵
- ↵
Request Permissions
If y'all wish to reuse any or all of this article please employ the link below which will take you to the Copyright Clearance Centre's RightsLink service. You will exist able to get a quick toll and instant permission to reuse the content in many different ways.
Copyright data:
Copyright 2002 Athenaeum of Disease in Childhood
Linked Articles
- Atoms
Source: https://adc.bmj.com/content/87/3/198
0 Response to "Signs to Know That My Vp Shunt Is Working Again"
Post a Comment